From fef1379537070795c6cfc75f46c0d1f434b1d3ce Mon Sep 17 00:00:00 2001
From: Jay Phelps <hello@jayphelps.com>
Date: Sat, 16 Nov 2019 16:43:19 -0500
Subject: [PATCH] Indirect calls on null now either trap with `unreachable` or,
 if exception-handlig is enabled, throws a Wasm exception

---
 .github/workflows/ci.yml                      |  4 +-
 examples/game-of-life/build/untouched.wat     | 17 ++---
 examples/mandelbrot/build/untouched.wat       |  1 +
 examples/n-body/build/untouched.wat           |  1 +
 examples/pson/build/untouched.wat             |  1 +
 lib/i64/build/untouched.wat                   |  1 +
 src/compiler.ts                               | 40 ++++++++++--
 tests/allocators/buddy/untouched.wat          | 17 ++---
 tests/allocators/rt-full/untouched.wat        | 65 ++++++++++---------
 tests/allocators/rt-stub/untouched.wat        | 11 ++--
 tests/compiler/ReturnType.optimized.wat       |  2 +-
 tests/compiler/ReturnType.untouched.wat       |  1 +
 tests/compiler/abi.optimized.wat              |  2 +-
 tests/compiler/abi.untouched.wat              |  1 +
 tests/compiler/asc-constants.optimized.wat    |  4 +-
 tests/compiler/asc-constants.untouched.wat    |  1 +
 tests/compiler/assert-nonnull.optimized.wat   |  2 +-
 tests/compiler/assert-nonnull.untouched.wat   |  1 +
 tests/compiler/assert.optimized.wat           |  2 +-
 tests/compiler/assert.untouched.wat           |  1 +
 tests/compiler/binary.optimized.wat           |  5 +-
 tests/compiler/binary.untouched.wat           |  1 +
 tests/compiler/bool.optimized.wat             |  2 +-
 tests/compiler/bool.untouched.wat             |  1 +
 tests/compiler/builtins.optimized.wat         |  5 +-
 tests/compiler/builtins.untouched.wat         |  1 +
 tests/compiler/call-inferred.optimized.wat    |  2 +-
 tests/compiler/call-inferred.untouched.wat    |  1 +
 tests/compiler/call-optional.optimized.wat    |  2 +-
 tests/compiler/call-optional.untouched.wat    |  1 +
 tests/compiler/call-super.optimized.wat       |  2 +-
 tests/compiler/call-super.untouched.wat       |  1 +
 tests/compiler/class-extends.optimized.wat    |  2 +-
 tests/compiler/class-extends.untouched.wat    |  1 +
 .../compiler/class-overloading.optimized.wat  |  4 +-
 .../compiler/class-overloading.untouched.wat  |  1 +
 .../class-static-function.optimized.wat       |  2 +-
 .../class-static-function.untouched.wat       |  1 +
 tests/compiler/class.optimized.wat            |  4 +-
 tests/compiler/class.untouched.wat            |  1 +
 tests/compiler/closure.untouched.wat          |  1 +
 tests/compiler/comma.optimized.wat            |  2 +-
 tests/compiler/comma.untouched.wat            |  1 +
 tests/compiler/constructor.optimized.wat      |  2 +-
 tests/compiler/constructor.untouched.wat      |  1 +
 tests/compiler/continue.optimized.wat         |  2 +-
 tests/compiler/continue.untouched.wat         |  1 +
 tests/compiler/declare.optimized.wat          |  2 +-
 tests/compiler/declare.untouched.wat          |  1 +
 tests/compiler/do.optimized.wat               |  2 +-
 tests/compiler/do.untouched.wat               |  1 +
 tests/compiler/empty.optimized.wat            |  2 +-
 tests/compiler/empty.untouched.wat            |  1 +
 tests/compiler/enum.optimized.wat             |  2 +-
 tests/compiler/enum.untouched.wat             |  1 +
 tests/compiler/export-default.optimized.wat   |  3 +
 tests/compiler/export-default.untouched.wat   |  1 +
 tests/compiler/export.optimized.wat           |  3 +
 tests/compiler/export.untouched.wat           |  1 +
 tests/compiler/exports.optimized.wat          |  2 +-
 tests/compiler/exports.untouched.wat          |  1 +
 tests/compiler/external.optimized.wat         |  2 +-
 tests/compiler/external.untouched.wat         |  1 +
 tests/compiler/features/exception-handling.js |  8 +++
 .../compiler/features/exception-handling.json |  8 +++
 .../features/exception-handling.optimized.wat | 24 +++++++
 tests/compiler/features/exception-handling.ts | 12 ++++
 .../features/exception-handling.untouched.wat | 41 ++++++++++++
 .../js-bigint-integration.optimized.wat       |  2 +-
 .../js-bigint-integration.untouched.wat       |  1 +
 .../features/mutable-globals.optimized.wat    |  2 +-
 .../features/mutable-globals.untouched.wat    |  1 +
 .../features/reference-types.optimized.wat    |  7 +-
 .../features/reference-types.untouched.wat    |  1 +
 tests/compiler/features/simd.untouched.wat    |  1 +
 tests/compiler/features/threads.optimized.wat |  2 +-
 tests/compiler/features/threads.untouched.wat |  1 +
 tests/compiler/for.optimized.wat              |  2 +-
 tests/compiler/for.untouched.wat              |  1 +
 tests/compiler/function-expression.js         |  6 ++
 .../function-expression.optimized.wat         | 13 +++-
 tests/compiler/function-expression.ts         |  9 ++-
 .../function-expression.untouched.wat         | 20 ++++--
 tests/compiler/function-types.optimized.wat   |  2 +-
 tests/compiler/function-types.untouched.wat   |  1 +
 tests/compiler/function.optimized.wat         |  4 +-
 tests/compiler/function.untouched.wat         |  1 +
 tests/compiler/getter-call.optimized.wat      |  2 +-
 tests/compiler/getter-call.untouched.wat      |  1 +
 tests/compiler/getter-setter.optimized.wat    |  2 +-
 tests/compiler/getter-setter.untouched.wat    |  1 +
 tests/compiler/i64-polyfill.optimized.wat     |  5 +-
 tests/compiler/i64-polyfill.untouched.wat     |  1 +
 tests/compiler/if.optimized.wat               |  2 +-
 tests/compiler/if.untouched.wat               |  1 +
 tests/compiler/import.optimized.wat           |  4 +-
 tests/compiler/import.untouched.wat           |  1 +
 tests/compiler/indexof-valueof.optimized.wat  |  2 +-
 tests/compiler/indexof-valueof.untouched.wat  |  1 +
 tests/compiler/infer-generic.optimized.wat    |  2 +-
 tests/compiler/infer-generic.untouched.wat    |  1 +
 tests/compiler/infer-type.optimized.wat       |  2 +-
 tests/compiler/infer-type.untouched.wat       |  1 +
 .../inlining-blocklocals.optimized.wat        |  2 +-
 .../inlining-blocklocals.untouched.wat        |  1 +
 .../compiler/inlining-recursive.optimized.wat |  2 +-
 .../compiler/inlining-recursive.untouched.wat |  1 +
 tests/compiler/inlining.optimized.wat         |  2 +-
 tests/compiler/inlining.untouched.wat         |  1 +
 tests/compiler/instanceof.optimized.wat       |  2 +-
 tests/compiler/instanceof.untouched.wat       |  1 +
 tests/compiler/limits.optimized.wat           |  4 +-
 tests/compiler/limits.untouched.wat           |  1 +
 tests/compiler/literals.optimized.wat         |  4 +-
 tests/compiler/literals.untouched.wat         |  1 +
 tests/compiler/logical.optimized.wat          |  2 +-
 tests/compiler/logical.untouched.wat          |  1 +
 tests/compiler/loop-flow.optimized.wat        |  2 +-
 tests/compiler/loop-flow.untouched.wat        |  1 +
 tests/compiler/loop-wrap.optimized.wat        |  2 +-
 tests/compiler/loop-wrap.untouched.wat        |  1 +
 tests/compiler/mandelbrot.optimized.wat       | 14 ++--
 tests/compiler/mandelbrot.untouched.wat       |  1 +
 tests/compiler/many-locals.optimized.wat      |  2 +-
 tests/compiler/many-locals.untouched.wat      |  1 +
 tests/compiler/memcpy.optimized.wat           |  2 +-
 tests/compiler/memcpy.untouched.wat           |  1 +
 tests/compiler/memmove.optimized.wat          |  2 +-
 tests/compiler/memmove.untouched.wat          |  1 +
 tests/compiler/memset.optimized.wat           |  2 +-
 tests/compiler/memset.untouched.wat           |  1 +
 tests/compiler/merge.optimized.wat            |  4 +-
 tests/compiler/merge.untouched.wat            |  1 +
 .../named-export-default.optimized.wat        |  2 +-
 .../named-export-default.untouched.wat        |  1 +
 .../named-import-default.optimized.wat        |  2 +-
 .../named-import-default.untouched.wat        |  1 +
 tests/compiler/namespace.optimized.wat        |  2 +-
 tests/compiler/namespace.untouched.wat        |  1 +
 tests/compiler/number.optimized.wat           |  2 +-
 tests/compiler/number.untouched.wat           |  1 +
 .../optional-typeparameters.optimized.wat     |  2 +-
 .../optional-typeparameters.untouched.wat     |  1 +
 tests/compiler/overflow.optimized.wat         |  4 +-
 tests/compiler/overflow.untouched.wat         |  1 +
 .../portable-conversions.optimized.wat        |  2 +-
 .../portable-conversions.untouched.wat        |  1 +
 tests/compiler/possibly-null.optimized.wat    |  2 +-
 tests/compiler/possibly-null.untouched.wat    |  1 +
 tests/compiler/rc/global-init.optimized.wat   |  2 +-
 tests/compiler/rc/global-init.untouched.wat   |  1 +
 tests/compiler/rc/local-init.optimized.wat    |  2 +-
 tests/compiler/rc/local-init.untouched.wat    |  1 +
 .../rc/logical-and-mismatch.optimized.wat     |  2 +-
 .../rc/logical-and-mismatch.untouched.wat     |  1 +
 .../rc/logical-or-mismatch.optimized.wat      |  2 +-
 .../rc/logical-or-mismatch.untouched.wat      |  1 +
 tests/compiler/rc/rereturn.optimized.wat      |  2 +-
 tests/compiler/rc/rereturn.untouched.wat      |  1 +
 .../rc/ternary-mismatch.optimized.wat         |  2 +-
 .../rc/ternary-mismatch.untouched.wat         |  1 +
 tests/compiler/recursive.optimized.wat        |  2 +-
 tests/compiler/recursive.untouched.wat        |  1 +
 tests/compiler/reexport.optimized.wat         |  3 +
 tests/compiler/reexport.untouched.wat         |  1 +
 tests/compiler/rereexport.optimized.wat       |  4 +-
 tests/compiler/rereexport.untouched.wat       |  1 +
 tests/compiler/resolve-access.optimized.wat   |  5 +-
 tests/compiler/resolve-access.untouched.wat   |  1 +
 tests/compiler/resolve-binary.optimized.wat   |  2 +-
 tests/compiler/resolve-binary.untouched.wat   |  1 +
 .../resolve-elementaccess.optimized.wat       |  2 +-
 .../resolve-elementaccess.untouched.wat       |  1 +
 .../resolve-function-expression.optimized.wat |  2 +-
 .../resolve-function-expression.untouched.wat |  1 +
 tests/compiler/resolve-nested.optimized.wat   |  2 +-
 tests/compiler/resolve-nested.untouched.wat   |  1 +
 tests/compiler/resolve-new.optimized.wat      |  2 +-
 tests/compiler/resolve-new.untouched.wat      |  1 +
 .../resolve-propertyaccess.optimized.wat      |  2 +-
 .../resolve-propertyaccess.untouched.wat      |  1 +
 tests/compiler/resolve-ternary.optimized.wat  |  2 +-
 tests/compiler/resolve-ternary.untouched.wat  |  1 +
 tests/compiler/resolve-unary.optimized.wat    |  2 +-
 tests/compiler/resolve-unary.untouched.wat    |  1 +
 tests/compiler/retain-i32.optimized.wat       |  2 +-
 tests/compiler/retain-i32.untouched.wat       |  1 +
 .../retain-release-sanity.optimized.wat       |  2 +-
 .../retain-release-sanity.untouched.wat       |  1 +
 tests/compiler/retain-release.optimized.wat   |  5 +-
 tests/compiler/retain-release.untouched.wat   |  1 +
 tests/compiler/rt/flags.untouched.wat         |  1 +
 tests/compiler/rt/ids.optimized.wat           |  2 +-
 tests/compiler/rt/ids.untouched.wat           |  1 +
 tests/compiler/rt/instanceof.optimized.wat    |  2 +-
 tests/compiler/rt/instanceof.untouched.wat    |  1 +
 tests/compiler/rt/stub-realloc.optimized.wat  |  3 +
 tests/compiler/rt/stub-realloc.untouched.wat  |  1 +
 tests/compiler/runtime-full.optimized.wat     |  2 +-
 tests/compiler/runtime-full.untouched.wat     |  1 +
 tests/compiler/runtime-half.optimized.wat     |  2 +-
 tests/compiler/runtime-half.untouched.wat     |  1 +
 tests/compiler/runtime-none.optimized.wat     |  2 +-
 tests/compiler/runtime-none.untouched.wat     |  1 +
 tests/compiler/runtime-stub.optimized.wat     |  3 +
 tests/compiler/runtime-stub.untouched.wat     |  1 +
 tests/compiler/scoped.optimized.wat           |  2 +-
 tests/compiler/scoped.untouched.wat           |  1 +
 tests/compiler/simd.untouched.wat             |  1 +
 tests/compiler/static-this.optimized.wat      |  2 +-
 tests/compiler/static-this.untouched.wat      |  1 +
 tests/compiler/std/array-access.optimized.wat |  2 +-
 tests/compiler/std/array-access.untouched.wat |  1 +
 .../compiler/std/array-literal.optimized.wat  |  2 +-
 .../compiler/std/array-literal.untouched.wat  |  1 +
 tests/compiler/std/array.optimized.wat        | 14 ++--
 tests/compiler/std/array.untouched.wat        |  1 +
 tests/compiler/std/arraybuffer.optimized.wat  |  2 +-
 tests/compiler/std/arraybuffer.untouched.wat  |  1 +
 tests/compiler/std/dataview.optimized.wat     |  2 +-
 tests/compiler/std/dataview.untouched.wat     |  1 +
 tests/compiler/std/date.optimized.wat         | 10 +--
 tests/compiler/std/date.untouched.wat         |  1 +
 tests/compiler/std/hash.optimized.wat         |  2 +-
 tests/compiler/std/hash.untouched.wat         |  1 +
 tests/compiler/std/libm.optimized.wat         | 23 +++----
 tests/compiler/std/libm.untouched.wat         |  1 +
 tests/compiler/std/map.optimized.wat          |  2 +-
 tests/compiler/std/map.untouched.wat          |  1 +
 tests/compiler/std/math.optimized.wat         | 59 +++++++----------
 tests/compiler/std/math.untouched.wat         |  1 +
 tests/compiler/std/mod.optimized.wat          | 11 ++--
 tests/compiler/std/mod.untouched.wat          |  1 +
 tests/compiler/std/new.optimized.wat          |  2 +-
 tests/compiler/std/new.untouched.wat          |  1 +
 .../compiler/std/object-literal.optimized.wat |  2 +-
 .../compiler/std/object-literal.untouched.wat |  1 +
 tests/compiler/std/object.optimized.wat       |  2 +-
 tests/compiler/std/object.untouched.wat       |  1 +
 .../std/operator-overloading.optimized.wat    |  2 +-
 .../std/operator-overloading.untouched.wat    |  1 +
 tests/compiler/std/pointer.optimized.wat      |  2 +-
 tests/compiler/std/pointer.untouched.wat      |  1 +
 tests/compiler/std/polyfills.optimized.wat    |  4 +-
 tests/compiler/std/polyfills.untouched.wat    |  1 +
 tests/compiler/std/set.optimized.wat          |  2 +-
 tests/compiler/std/set.untouched.wat          |  1 +
 tests/compiler/std/simd.optimized.wat         |  2 +-
 tests/compiler/std/simd.untouched.wat         |  1 +
 tests/compiler/std/static-array.optimized.wat |  2 +-
 tests/compiler/std/static-array.untouched.wat |  1 +
 .../std/string-encoding.optimized.wat         |  2 +-
 .../std/string-encoding.untouched.wat         |  1 +
 tests/compiler/std/string.optimized.wat       | 11 ++--
 tests/compiler/std/string.untouched.wat       |  1 +
 tests/compiler/std/symbol.optimized.wat       |  2 +-
 tests/compiler/std/symbol.untouched.wat       |  1 +
 tests/compiler/std/trace.optimized.wat        |  2 +-
 tests/compiler/std/trace.untouched.wat        |  1 +
 tests/compiler/std/typedarray.optimized.wat   | 26 +++-----
 tests/compiler/std/typedarray.untouched.wat   |  1 +
 tests/compiler/switch.optimized.wat           |  2 +-
 tests/compiler/switch.untouched.wat           |  1 +
 tests/compiler/ternary.optimized.wat          |  2 +-
 tests/compiler/ternary.untouched.wat          |  1 +
 tests/compiler/typealias.optimized.wat        |  2 +-
 tests/compiler/typealias.untouched.wat        |  1 +
 tests/compiler/typeof.optimized.wat           |  3 +
 tests/compiler/typeof.untouched.wat           |  1 +
 tests/compiler/unary.optimized.wat            |  5 +-
 tests/compiler/unary.untouched.wat            |  1 +
 tests/compiler/void.optimized.wat             |  4 +-
 tests/compiler/void.untouched.wat             |  1 +
 tests/compiler/wasi.optimized.wat             |  2 +-
 tests/compiler/wasi.untouched.wat             |  1 +
 tests/compiler/while.optimized.wat            |  2 +-
 tests/compiler/while.untouched.wat            |  1 +
 tests/compiler/wildcard-export.optimized.wat  |  4 +-
 tests/compiler/wildcard-export.untouched.wat  |  1 +
 tests/features.json                           |  8 +++
 tests/runtime/untouched.wat                   | 61 ++++++++---------
 281 files changed, 623 insertions(+), 340 deletions(-)
 create mode 100644 tests/compiler/features/exception-handling.js
 create mode 100644 tests/compiler/features/exception-handling.json
 create mode 100644 tests/compiler/features/exception-handling.optimized.wat
 create mode 100644 tests/compiler/features/exception-handling.ts
 create mode 100644 tests/compiler/features/exception-handling.untouched.wat
 create mode 100644 tests/compiler/function-expression.js

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 2d1c5a442b..72cc40680f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -70,9 +70,9 @@ jobs:
       run: npm run clean
     - name: Test experimental features
       env:
-        ASC_FEATURES: mutable-globals,threads,reference-types,bigint-integration
+        ASC_FEATURES: mutable-globals,threads,reference-types,bigint-integration,exception-handling
       run: |
-        npm run test:compiler rt/flags features/js-bigint-integration features/reference-types features/threads
+        npm run test:compiler rt/flags features/js-bigint-integration features/reference-types features/threads features/exception-handling
   test-runtime:
     name: "Test runtimes on node: node"
     runs-on: ubuntu-latest
diff --git a/examples/game-of-life/build/untouched.wat b/examples/game-of-life/build/untouched.wat
index 9f380f3a71..430301828a 100644
--- a/examples/game-of-life/build/untouched.wat
+++ b/examples/game-of-life/build/untouched.wat
@@ -60,7 +60,7 @@
        global.get $assembly/config/BGR_DEAD
        i32.const 16777215
        i32.and
-      else       
+      else
        global.get $assembly/config/BGR_ALIVE
        i32.const -16777216
        i32.or
@@ -134,7 +134,7 @@
     i32.eq
     if (result i32)
      local.get $0
-    else     
+    else
      local.get $2
      i32.const 1
      i32.sub
@@ -145,7 +145,7 @@
     i32.eq
     if (result i32)
      i32.const 0
-    else     
+    else
      local.get $2
      i32.const 1
      i32.add
@@ -165,7 +165,7 @@
       i32.eq
       if (result i32)
        local.get $1
-      else       
+      else
        local.get $5
        i32.const 1
        i32.sub
@@ -176,7 +176,7 @@
       i32.eq
       if (result i32)
        i32.const 0
-      else       
+      else
        local.get $5
        i32.const 1
        i32.add
@@ -367,7 +367,7 @@
         i32.shl
         local.get $14
         i32.store
-       else        
+       else
         local.get $5
         local.set $16
         local.get $2
@@ -388,7 +388,7 @@
         local.get $14
         i32.store
        end
-      else       
+      else
        local.get $9
        i32.const 3
        i32.eq
@@ -412,7 +412,7 @@
         i32.shl
         local.get $8
         i32.store
-       else        
+       else
         local.get $5
         local.set $15
         local.get $2
@@ -563,5 +563,6 @@
   end
  )
  (func $null (; 4 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/examples/mandelbrot/build/untouched.wat b/examples/mandelbrot/build/untouched.wat
index 8db1ec8f17..48f1c762aa 100644
--- a/examples/mandelbrot/build/untouched.wat
+++ b/examples/mandelbrot/build/untouched.wat
@@ -251,5 +251,6 @@
   end
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/examples/n-body/build/untouched.wat b/examples/n-body/build/untouched.wat
index f708bee1e2..f5f523fa0a 100644
--- a/examples/n-body/build/untouched.wat
+++ b/examples/n-body/build/untouched.wat
@@ -2225,5 +2225,6 @@
   global.set $~lib/rt/stub/offset
  )
  (func $null (; 24 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/examples/pson/build/untouched.wat b/examples/pson/build/untouched.wat
index 2f37a02804..1fce171637 100644
--- a/examples/pson/build/untouched.wat
+++ b/examples/pson/build/untouched.wat
@@ -484,5 +484,6 @@
   end
  )
  (func $null (; 18 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/lib/i64/build/untouched.wat b/lib/i64/build/untouched.wat
index 75dce31faf..2c0b2d1633 100644
--- a/lib/i64/build/untouched.wat
+++ b/lib/i64/build/untouched.wat
@@ -749,5 +749,6 @@
   global.set $assembly/i64/hi
  )
  (func $null (; 31 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/src/compiler.ts b/src/compiler.ts
index 161bd21b8f..d3de096a46 100644
--- a/src/compiler.ts
+++ b/src/compiler.ts
@@ -408,6 +408,11 @@ export class Compiler extends DiagnosticEmitter {
     module.removeGlobal(BuiltinSymbols.rtti_base);
     if (this.runtimeFeatures & RuntimeFeatures.RTTI) compileRTTI(this);
 
+    // set up function table
+    var functionTable = this.functionTable;
+    module.setFunctionTable(functionTable.length, 0xffffffff, functionTable, module.i32(0));
+    this.addNullPointerExceptionHandling(module);
+
     // update the heap base pointer
     var memoryOffset = this.memoryOffset;
     memoryOffset = i64_align(memoryOffset, options.usizeType.byteSize);
@@ -447,11 +452,6 @@ export class Compiler extends DiagnosticEmitter {
     // import memory if requested (default memory is named '0' by Binaryen)
     if (options.importMemory) module.addMemoryImport("0", "env", "memory", isSharedMemory);
 
-    // set up function table
-    var functionTable = this.functionTable;
-    module.setFunctionTable(functionTable.length, 0xffffffff, functionTable, module.i32(0));
-    module.addFunction("null", this.ensureFunctionType(null, Type.void), null, module.block(null, []));
-
     // import table if requested (default table is named '0' by Binaryen)
     if (options.importTable) module.addTableImport("0", "env", "table");
 
@@ -462,6 +462,36 @@ export class Compiler extends DiagnosticEmitter {
     return module;
   }
 
+  addNullPointerExceptionHandling(module: Module) {
+    if (this.options.hasFeature(Feature.EXCEPTION_HANDLING)) {
+      let message = this.ensureStaticString("null is not a function");
+      let exceptionType = module.addFunctionType(
+        "NullPointerException",
+        NativeType.None,
+        [NativeType.I32]
+      );
+
+      module.addEvent("NullPointerException", 0, exceptionType);
+      module.addFunction(
+        "null",
+        this.ensureFunctionType(null, Type.void),
+        null,
+        module.block(null, [
+          module.throw("NullPointerException", [message])
+        ])
+      );
+    } else {
+      module.addFunction(
+        "null",
+        this.ensureFunctionType(null, Type.void),
+        null,
+        module.block(null, [
+          module.unreachable()
+        ])
+      );
+    }
+  }
+
   // === Exports ==================================================================================
 
   /** Applies the respective module exports for the specified file. */
diff --git a/tests/allocators/buddy/untouched.wat b/tests/allocators/buddy/untouched.wat
index 7c40826518..42999cb997 100644
--- a/tests/allocators/buddy/untouched.wat
+++ b/tests/allocators/buddy/untouched.wat
@@ -88,7 +88,7 @@
      local.get $1
      i32.const 3
      i32.and
-    else     
+    else
      i32.const 0
     end
     if
@@ -1293,7 +1293,7 @@
    i32.le_u
    if (result i32)
     i32.const 1
-   else    
+   else
     local.get $5
     local.get $3
     i32.add
@@ -1413,7 +1413,7 @@
       end
      end
     end
-   else    
+   else
     local.get $4
     i32.const 7
     i32.and
@@ -1554,7 +1554,7 @@
       local.get $4
       i32.load8_u
       i32.eq
-     else      
+     else
       i32.const 0
      end
      if
@@ -1581,7 +1581,7 @@
     local.get $4
     i32.load8_u
     i32.sub
-   else    
+   else
     i32.const 0
    end
   end
@@ -2019,7 +2019,7 @@
       i32.ne
       if (result i32)
        i32.const 1
-      else       
+      else
        local.get $2
        i32.const 0
        i32.eq
@@ -2060,7 +2060,7 @@
       i32.div_u
       global.get $assembly/buddy/List.SIZE
       i32.add
-     else      
+     else
       local.get $3
      end
      local.set $4
@@ -2164,7 +2164,7 @@
      call $assembly/buddy/parent_is_split
      if (result i32)
       i32.const 1
-     else      
+     else
       local.get $1
       global.get $assembly/buddy/bucket_limit
       i32.eq
@@ -2207,5 +2207,6 @@
   call $start:assembly/index
  )
  (func $null (; 26 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/allocators/rt-full/untouched.wat b/tests/allocators/rt-full/untouched.wat
index addfbf47c6..e6347f31e8 100644
--- a/tests/allocators/rt-full/untouched.wat
+++ b/tests/allocators/rt-full/untouched.wat
@@ -77,7 +77,7 @@
    local.get $3
    i32.const 1073741808
    i32.lt_u
-  else   
+  else
    i32.const 0
   end
   i32.eqz
@@ -99,7 +99,7 @@
    i32.const 4
    i32.shr_u
    local.set $5
-  else   
+  else
    i32.const 31
    local.get $3
    i32.clz
@@ -129,7 +129,7 @@
    local.get $5
    i32.const 16
    i32.lt_u
-  else   
+  else
    i32.const 0
   end
   i32.eqz
@@ -444,7 +444,7 @@
    local.get $8
    i32.const 1073741808
    i32.lt_u
-  else   
+  else
    i32.const 0
   end
   i32.eqz
@@ -487,7 +487,7 @@
    i32.const 4
    i32.shr_u
    local.set $10
-  else   
+  else
    i32.const 31
    local.get $8
    i32.clz
@@ -517,7 +517,7 @@
    local.get $10
    i32.const 16
    i32.lt_u
-  else   
+  else
    i32.const 0
   end
   i32.eqz
@@ -636,7 +636,7 @@
    i32.const 15
    i32.and
    i32.eqz
-  else   
+  else
    i32.const 0
   end
   if (result i32)
@@ -644,7 +644,7 @@
    i32.const 15
    i32.and
    i32.eqz
-  else   
+  else
    i32.const 0
   end
   i32.eqz
@@ -694,10 +694,10 @@
     local.get $4
     i32.load
     local.set $5
-   else    
+   else
     nop
    end
-  else   
+  else
    local.get $1
    local.get $0
    i32.const 1572
@@ -815,7 +815,7 @@
    memory.grow
    i32.const 0
    i32.lt_s
-  else   
+  else
    i32.const 0
   end
   if
@@ -973,7 +973,7 @@
    i32.const 4
    i32.shr_u
    local.set $3
-  else   
+  else
    local.get $1
    i32.const 536870904
    i32.lt_u
@@ -988,7 +988,7 @@
     i32.add
     i32.const 1
     i32.sub
-   else    
+   else
     local.get $1
    end
    local.set $4
@@ -1021,7 +1021,7 @@
    local.get $3
    i32.const 16
    i32.lt_u
-  else   
+  else
    i32.const 0
   end
   i32.eqz
@@ -1073,7 +1073,7 @@
    if
     i32.const 0
     local.set $7
-   else    
+   else
     local.get $5
     i32.ctz
     local.set $2
@@ -1121,7 +1121,7 @@
     end
     local.set $7
    end
-  else   
+  else
    block $~lib/rt/tlsf/GETHEAD|inlined.3 (result i32)
     local.get $0
     local.set $9
@@ -1253,7 +1253,7 @@
    local.get $0
    local.get $5
    call $~lib/rt/tlsf/insertBlock
-  else   
+  else
    local.get $1
    local.get $3
    i32.const 1
@@ -1505,7 +1505,7 @@
      local.get $1
      i32.const 3
      i32.and
-    else     
+    else
      i32.const 0
     end
     if
@@ -2710,7 +2710,7 @@
    i32.le_u
    if (result i32)
     i32.const 1
-   else    
+   else
     local.get $5
     local.get $3
     i32.add
@@ -2830,7 +2830,7 @@
       end
      end
     end
-   else    
+   else
     local.get $4
     i32.const 7
     i32.and
@@ -2931,7 +2931,7 @@
    i32.const 15
    i32.and
    i32.eqz
-  else   
+  else
    i32.const 0
   end
   i32.eqz
@@ -3060,7 +3060,7 @@
     global.get $~lib/rt/tlsf/ROOT
     local.get $0
     call $~lib/rt/tlsf/freeBlock
-   else    
+   else
     local.get $0
     i32.const -2147483648
     i32.const 0
@@ -3069,7 +3069,7 @@
     i32.or
     i32.store offset=4
    end
-  else   
+  else
    local.get $2
    i32.const 0
    i32.gt_u
@@ -3106,7 +3106,7 @@
      local.get $0
      call $~lib/rt/pure/appendRoot
     end
-   else    
+   else
     local.get $0
     local.get $1
     i32.const 268435455
@@ -3195,7 +3195,7 @@
    if
     local.get $0
     call $~lib/rt/pure/scanBlack
-   else    
+   else
     local.get $0
     local.get $1
     i32.const 1879048192
@@ -3228,7 +3228,7 @@
    i32.const -2147483648
    i32.and
    i32.eqz
-  else   
+  else
    i32.const 0
   end
   if
@@ -3292,7 +3292,7 @@
      i32.and
      i32.const 0
      i32.gt_u
-    else     
+    else
      i32.const 0
     end
     if
@@ -3305,7 +3305,7 @@
      i32.const 4
      i32.add
      local.set $1
-    else     
+    else
      local.get $5
      i32.const 1879048192
      i32.and
@@ -3316,14 +3316,14 @@
       i32.const 268435455
       i32.and
       i32.eqz
-     else      
+     else
       i32.const 0
      end
      if
       global.get $~lib/rt/tlsf/ROOT
       local.get $4
       call $~lib/rt/tlsf/freeBlock
-     else      
+     else
       local.get $4
       local.get $5
       i32.const -2147483648
@@ -3474,7 +3474,7 @@
       local.get $4
       i32.load8_u
       i32.eq
-     else      
+     else
       i32.const 0
      end
      if
@@ -3501,7 +3501,7 @@
     local.get $4
     i32.load8_u
     i32.sub
-   else    
+   else
     i32.const 0
    end
   end
@@ -3718,5 +3718,6 @@
   end
  )
  (func $null (; 33 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/allocators/rt-stub/untouched.wat b/tests/allocators/rt-stub/untouched.wat
index 97f25aaef7..85f261ac8c 100644
--- a/tests/allocators/rt-stub/untouched.wat
+++ b/tests/allocators/rt-stub/untouched.wat
@@ -160,7 +160,7 @@
      local.get $1
      i32.const 3
      i32.and
-    else     
+    else
      i32.const 0
     end
     if
@@ -1365,7 +1365,7 @@
    i32.le_u
    if (result i32)
     i32.const 1
-   else    
+   else
     local.get $5
     local.get $3
     i32.add
@@ -1485,7 +1485,7 @@
       end
      end
     end
-   else    
+   else
     local.get $4
     i32.const 7
     i32.and
@@ -1626,7 +1626,7 @@
       local.get $4
       i32.load8_u
       i32.eq
-     else      
+     else
       i32.const 0
      end
      if
@@ -1653,7 +1653,7 @@
     local.get $4
     i32.load8_u
     i32.sub
-   else    
+   else
     i32.const 0
    end
   end
@@ -1678,5 +1678,6 @@
   global.set $~lib/rt/stub/offset
  )
  (func $null (; 14 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/ReturnType.optimized.wat b/tests/compiler/ReturnType.optimized.wat
index bb456a1172..8a6433fd8c 100644
--- a/tests/compiler/ReturnType.optimized.wat
+++ b/tests/compiler/ReturnType.optimized.wat
@@ -3,6 +3,6 @@
  (memory $0 0)
  (export "memory" (memory $0))
  (func $null (; 0 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/ReturnType.untouched.wat b/tests/compiler/ReturnType.untouched.wat
index 29ee81b836..6cdcf09d9b 100644
--- a/tests/compiler/ReturnType.untouched.wat
+++ b/tests/compiler/ReturnType.untouched.wat
@@ -5,5 +5,6 @@
  (elem (i32.const 0) $null)
  (export "memory" (memory $0))
  (func $null (; 0 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/abi.optimized.wat b/tests/compiler/abi.optimized.wat
index daf93339b5..6516fb8cf7 100644
--- a/tests/compiler/abi.optimized.wat
+++ b/tests/compiler/abi.optimized.wat
@@ -20,6 +20,6 @@
   global.set $abi/y
  )
  (func $null (; 2 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/abi.untouched.wat b/tests/compiler/abi.untouched.wat
index 4cabc044e6..1f0d877b9d 100644
--- a/tests/compiler/abi.untouched.wat
+++ b/tests/compiler/abi.untouched.wat
@@ -203,5 +203,6 @@
   call $start:abi
  )
  (func $null (; 7 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/asc-constants.optimized.wat b/tests/compiler/asc-constants.optimized.wat
index e2acb0a3b8..8a6433fd8c 100644
--- a/tests/compiler/asc-constants.optimized.wat
+++ b/tests/compiler/asc-constants.optimized.wat
@@ -2,7 +2,7 @@
  (type $FUNCSIG$v (func))
  (memory $0 0)
  (export "memory" (memory $0))
- (func $start (; 0 ;) (type $FUNCSIG$v)
-  nop
+ (func $null (; 0 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/asc-constants.untouched.wat b/tests/compiler/asc-constants.untouched.wat
index 7e22a7c8a6..6bbba8edcf 100644
--- a/tests/compiler/asc-constants.untouched.wat
+++ b/tests/compiler/asc-constants.untouched.wat
@@ -53,5 +53,6 @@
   call $start:asc-constants
  )
  (func $null (; 2 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/assert-nonnull.optimized.wat b/tests/compiler/assert-nonnull.optimized.wat
index d739eba408..ff378bd07e 100644
--- a/tests/compiler/assert-nonnull.optimized.wat
+++ b/tests/compiler/assert-nonnull.optimized.wat
@@ -186,6 +186,6 @@
   end
  )
  (func $null (; 15 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/assert-nonnull.untouched.wat b/tests/compiler/assert-nonnull.untouched.wat
index 1a3744f8ed..712cca133d 100644
--- a/tests/compiler/assert-nonnull.untouched.wat
+++ b/tests/compiler/assert-nonnull.untouched.wat
@@ -365,5 +365,6 @@
   local.get $2
  )
  (func $null (; 19 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/assert.optimized.wat b/tests/compiler/assert.optimized.wat
index bb456a1172..8a6433fd8c 100644
--- a/tests/compiler/assert.optimized.wat
+++ b/tests/compiler/assert.optimized.wat
@@ -3,6 +3,6 @@
  (memory $0 0)
  (export "memory" (memory $0))
  (func $null (; 0 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/assert.untouched.wat b/tests/compiler/assert.untouched.wat
index 29ee81b836..6cdcf09d9b 100644
--- a/tests/compiler/assert.untouched.wat
+++ b/tests/compiler/assert.untouched.wat
@@ -5,5 +5,6 @@
  (elem (i32.const 0) $null)
  (export "memory" (memory $0))
  (func $null (; 0 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/binary.optimized.wat b/tests/compiler/binary.optimized.wat
index 91ecca9d9a..c3cc4a9ecc 100644
--- a/tests/compiler/binary.optimized.wat
+++ b/tests/compiler/binary.optimized.wat
@@ -260,8 +260,7 @@
     return
    end
    local.get $2
-   i64.const 0
-   i64.eq
+   i64.eqz
    if (result i64)
     local.get $1
     i64.const 0
@@ -708,6 +707,6 @@
   call $start:binary
  )
  (func $null (; 6 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/binary.untouched.wat b/tests/compiler/binary.untouched.wat
index 6986bd695f..408f7c143a 100644
--- a/tests/compiler/binary.untouched.wat
+++ b/tests/compiler/binary.untouched.wat
@@ -3323,5 +3323,6 @@
   call $start:binary
  )
  (func $null (; 8 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/bool.optimized.wat b/tests/compiler/bool.optimized.wat
index 5d46ff41ec..b38b9c7303 100644
--- a/tests/compiler/bool.optimized.wat
+++ b/tests/compiler/bool.optimized.wat
@@ -11,6 +11,6 @@
   call $start:bool
  )
  (func $null (; 2 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/bool.untouched.wat b/tests/compiler/bool.untouched.wat
index c22f19cecb..9220d657f9 100644
--- a/tests/compiler/bool.untouched.wat
+++ b/tests/compiler/bool.untouched.wat
@@ -119,5 +119,6 @@
   call $start:bool
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/builtins.optimized.wat b/tests/compiler/builtins.optimized.wat
index 12067737ed..d99fe9487b 100644
--- a/tests/compiler/builtins.optimized.wat
+++ b/tests/compiler/builtins.optimized.wat
@@ -33,7 +33,7 @@
  (data (i32.const 576) "\08\00\00\00\01\00\00\00\01\00\00\00\08\00\00\00v\00o\00i\00d")
  (data (i32.const 600) "\14\00\00\00\01\00\00\00\01\00\00\00\14\00\00\00s\00o\00m\00e\00 \00v\00a\00l\00u\00e")
  (table $0 4 funcref)
- (elem (i32.const 0) $start:builtins~anonymous|1 $start:builtins~anonymous|0 $start:builtins~anonymous|1 $start:builtins~anonymous|2)
+ (elem (i32.const 0) $null $start:builtins~anonymous|0 $start:builtins~anonymous|1 $start:builtins~anonymous|2)
  (global $builtins/b (mut i32) (i32.const 0))
  (global $builtins/i (mut i32) (i32.const 0))
  (global $builtins/I (mut i64) (i64.const 0))
@@ -879,4 +879,7 @@
  (func $start (; 10 ;) (type $FUNCSIG$v)
   call $start:builtins
  )
+ (func $null (; 11 ;) (type $FUNCSIG$v)
+  unreachable
+ )
 )
diff --git a/tests/compiler/builtins.untouched.wat b/tests/compiler/builtins.untouched.wat
index 969e412e64..af82e44a49 100644
--- a/tests/compiler/builtins.untouched.wat
+++ b/tests/compiler/builtins.untouched.wat
@@ -1883,5 +1883,6 @@
   call $start:builtins
  )
  (func $null (; 14 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/call-inferred.optimized.wat b/tests/compiler/call-inferred.optimized.wat
index 237fd9e1c9..a20d1124d1 100644
--- a/tests/compiler/call-inferred.optimized.wat
+++ b/tests/compiler/call-inferred.optimized.wat
@@ -13,6 +13,6 @@
   call $start:call-inferred
  )
  (func $null (; 2 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/call-inferred.untouched.wat b/tests/compiler/call-inferred.untouched.wat
index 97e21b27ca..749e360e3c 100644
--- a/tests/compiler/call-inferred.untouched.wat
+++ b/tests/compiler/call-inferred.untouched.wat
@@ -99,5 +99,6 @@
   call $start:call-inferred
  )
  (func $null (; 8 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/call-optional.optimized.wat b/tests/compiler/call-optional.optimized.wat
index ed4949d582..97391b4b9a 100644
--- a/tests/compiler/call-optional.optimized.wat
+++ b/tests/compiler/call-optional.optimized.wat
@@ -136,6 +136,6 @@
   call $start:call-optional
  )
  (func $null (; 5 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/call-optional.untouched.wat b/tests/compiler/call-optional.untouched.wat
index 57740d1e68..a9f93e398e 100644
--- a/tests/compiler/call-optional.untouched.wat
+++ b/tests/compiler/call-optional.untouched.wat
@@ -150,5 +150,6 @@
   call $start:call-optional
  )
  (func $null (; 5 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/call-super.optimized.wat b/tests/compiler/call-super.optimized.wat
index ad00d717d7..89ea5e9507 100644
--- a/tests/compiler/call-super.optimized.wat
+++ b/tests/compiler/call-super.optimized.wat
@@ -431,6 +431,6 @@
   call $call-super/test5
  )
  (func $null (; 15 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/call-super.untouched.wat b/tests/compiler/call-super.untouched.wat
index 816d5e9442..ccfa3f0be7 100644
--- a/tests/compiler/call-super.untouched.wat
+++ b/tests/compiler/call-super.untouched.wat
@@ -559,5 +559,6 @@
   call $start:call-super
  )
  (func $null (; 22 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/class-extends.optimized.wat b/tests/compiler/class-extends.optimized.wat
index 38988d5695..2f8515dd68 100644
--- a/tests/compiler/class-extends.optimized.wat
+++ b/tests/compiler/class-extends.optimized.wat
@@ -19,6 +19,6 @@
   i32.store16 offset=4
  )
  (func $null (; 1 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/class-extends.untouched.wat b/tests/compiler/class-extends.untouched.wat
index ea085c090d..ad211bc7ca 100644
--- a/tests/compiler/class-extends.untouched.wat
+++ b/tests/compiler/class-extends.untouched.wat
@@ -33,5 +33,6 @@
   call $~lib/rt/stub/__release
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/class-overloading.optimized.wat b/tests/compiler/class-overloading.optimized.wat
index 763941477c..048fa39844 100644
--- a/tests/compiler/class-overloading.optimized.wat
+++ b/tests/compiler/class-overloading.optimized.wat
@@ -7,7 +7,7 @@
  (func $class-overloading/test (; 0 ;) (type $FUNCSIG$vi) (param $0 i32)
   nop
  )
- (func $start (; 1 ;) (type $FUNCSIG$v)
-  nop
+ (func $null (; 1 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/class-overloading.untouched.wat b/tests/compiler/class-overloading.untouched.wat
index 65b67365da..32b4944b0d 100644
--- a/tests/compiler/class-overloading.untouched.wat
+++ b/tests/compiler/class-overloading.untouched.wat
@@ -34,5 +34,6 @@
   call $start:class-overloading
  )
  (func $null (; 6 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/class-static-function.optimized.wat b/tests/compiler/class-static-function.optimized.wat
index de95f9b786..11a5847e6e 100644
--- a/tests/compiler/class-static-function.optimized.wat
+++ b/tests/compiler/class-static-function.optimized.wat
@@ -29,6 +29,6 @@
   end
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/class-static-function.untouched.wat b/tests/compiler/class-static-function.untouched.wat
index 6eebcbd7e9..9889c1d7e2 100644
--- a/tests/compiler/class-static-function.untouched.wat
+++ b/tests/compiler/class-static-function.untouched.wat
@@ -39,5 +39,6 @@
   call $start:class-static-function
  )
  (func $null (; 5 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/class.optimized.wat b/tests/compiler/class.optimized.wat
index 9456feeee8..d9fcfd3465 100644
--- a/tests/compiler/class.optimized.wat
+++ b/tests/compiler/class.optimized.wat
@@ -25,7 +25,7 @@
   i32.store8 offset=6
   local.get $0
  )
- (func $start (; 1 ;) (type $FUNCSIG$v)
-  nop
+ (func $null (; 1 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/class.untouched.wat b/tests/compiler/class.untouched.wat
index 2f80550da2..efbac5dee6 100644
--- a/tests/compiler/class.untouched.wat
+++ b/tests/compiler/class.untouched.wat
@@ -119,5 +119,6 @@
   call $start:class
  )
  (func $null (; 9 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/closure.untouched.wat b/tests/compiler/closure.untouched.wat
index 29ee81b836..6cdcf09d9b 100644
--- a/tests/compiler/closure.untouched.wat
+++ b/tests/compiler/closure.untouched.wat
@@ -5,5 +5,6 @@
  (elem (i32.const 0) $null)
  (export "memory" (memory $0))
  (func $null (; 0 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/comma.optimized.wat b/tests/compiler/comma.optimized.wat
index 87a8e1743f..f394636b2d 100644
--- a/tests/compiler/comma.optimized.wat
+++ b/tests/compiler/comma.optimized.wat
@@ -159,6 +159,6 @@
   call $start:comma
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/comma.untouched.wat b/tests/compiler/comma.untouched.wat
index 7c038e5db9..5a127c9b36 100644
--- a/tests/compiler/comma.untouched.wat
+++ b/tests/compiler/comma.untouched.wat
@@ -187,5 +187,6 @@
   call $start:comma
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/constructor.optimized.wat b/tests/compiler/constructor.optimized.wat
index 0d7b12b95d..967125cd72 100644
--- a/tests/compiler/constructor.optimized.wat
+++ b/tests/compiler/constructor.optimized.wat
@@ -175,6 +175,6 @@
   call $start:constructor
  )
  (func $null (; 4 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/constructor.untouched.wat b/tests/compiler/constructor.untouched.wat
index 55e22eb4a9..cf08ce09b0 100644
--- a/tests/compiler/constructor.untouched.wat
+++ b/tests/compiler/constructor.untouched.wat
@@ -324,5 +324,6 @@
   call $start:constructor
  )
  (func $null (; 15 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/continue.optimized.wat b/tests/compiler/continue.optimized.wat
index 0f8ce07948..f049f50f0b 100644
--- a/tests/compiler/continue.optimized.wat
+++ b/tests/compiler/continue.optimized.wat
@@ -31,6 +31,6 @@
   end
  )
  (func $null (; 1 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/continue.untouched.wat b/tests/compiler/continue.untouched.wat
index 37d5aba6cc..65213c39ca 100644
--- a/tests/compiler/continue.untouched.wat
+++ b/tests/compiler/continue.untouched.wat
@@ -38,5 +38,6 @@
   end
  )
  (func $null (; 1 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/declare.optimized.wat b/tests/compiler/declare.optimized.wat
index 7da25a0ead..ad18e47d67 100644
--- a/tests/compiler/declare.optimized.wat
+++ b/tests/compiler/declare.optimized.wat
@@ -40,6 +40,6 @@
   call $start:declare
  )
  (func $null (; 5 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/declare.untouched.wat b/tests/compiler/declare.untouched.wat
index 2946358847..eb6b9478f1 100644
--- a/tests/compiler/declare.untouched.wat
+++ b/tests/compiler/declare.untouched.wat
@@ -44,5 +44,6 @@
   call $start:declare
  )
  (func $null (; 5 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/do.optimized.wat b/tests/compiler/do.optimized.wat
index a951a3ca7d..afcfcf911e 100644
--- a/tests/compiler/do.optimized.wat
+++ b/tests/compiler/do.optimized.wat
@@ -149,6 +149,6 @@
   call $start:do
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/do.untouched.wat b/tests/compiler/do.untouched.wat
index dada59c30b..c0c7083bf9 100644
--- a/tests/compiler/do.untouched.wat
+++ b/tests/compiler/do.untouched.wat
@@ -166,5 +166,6 @@
   call $start:do
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/empty.optimized.wat b/tests/compiler/empty.optimized.wat
index bb456a1172..8a6433fd8c 100644
--- a/tests/compiler/empty.optimized.wat
+++ b/tests/compiler/empty.optimized.wat
@@ -3,6 +3,6 @@
  (memory $0 0)
  (export "memory" (memory $0))
  (func $null (; 0 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/empty.untouched.wat b/tests/compiler/empty.untouched.wat
index 29ee81b836..6cdcf09d9b 100644
--- a/tests/compiler/empty.untouched.wat
+++ b/tests/compiler/empty.untouched.wat
@@ -5,5 +5,6 @@
  (elem (i32.const 0) $null)
  (export "memory" (memory $0))
  (func $null (; 0 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/enum.optimized.wat b/tests/compiler/enum.optimized.wat
index 918613db6f..715f990863 100644
--- a/tests/compiler/enum.optimized.wat
+++ b/tests/compiler/enum.optimized.wat
@@ -68,6 +68,6 @@
   global.set $enum/NonConstant.ONE
  )
  (func $null (; 1 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/enum.untouched.wat b/tests/compiler/enum.untouched.wat
index 51d9aa74ba..d97a300cd8 100644
--- a/tests/compiler/enum.untouched.wat
+++ b/tests/compiler/enum.untouched.wat
@@ -84,5 +84,6 @@
   call $start:enum
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/export-default.optimized.wat b/tests/compiler/export-default.optimized.wat
index fbdbee4154..c6e1854a2e 100644
--- a/tests/compiler/export-default.optimized.wat
+++ b/tests/compiler/export-default.optimized.wat
@@ -7,4 +7,7 @@
  (func $export-default/theDefault (; 0 ;) (type $FUNCSIG$v)
   nop
  )
+ (func $null (; 1 ;) (type $FUNCSIG$v)
+  unreachable
+ )
 )
diff --git a/tests/compiler/export-default.untouched.wat b/tests/compiler/export-default.untouched.wat
index f367647567..9dcdac76e6 100644
--- a/tests/compiler/export-default.untouched.wat
+++ b/tests/compiler/export-default.untouched.wat
@@ -10,5 +10,6 @@
   nop
  )
  (func $null (; 1 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/export.optimized.wat b/tests/compiler/export.optimized.wat
index b5b3be4fa2..8244318fda 100644
--- a/tests/compiler/export.optimized.wat
+++ b/tests/compiler/export.optimized.wat
@@ -32,4 +32,7 @@
  (func $export/ns.one (; 3 ;) (type $FUNCSIG$v)
   nop
  )
+ (func $null (; 4 ;) (type $FUNCSIG$v)
+  unreachable
+ )
 )
diff --git a/tests/compiler/export.untouched.wat b/tests/compiler/export.untouched.wat
index fb06dd5c75..b9fb1ab593 100644
--- a/tests/compiler/export.untouched.wat
+++ b/tests/compiler/export.untouched.wat
@@ -38,5 +38,6 @@
   nop
  )
  (func $null (; 5 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/exports.optimized.wat b/tests/compiler/exports.optimized.wat
index 3befaaa6b6..7632e3c783 100644
--- a/tests/compiler/exports.optimized.wat
+++ b/tests/compiler/exports.optimized.wat
@@ -148,7 +148,7 @@
   global.set $~lib/rt/stub/offset
  )
  (func $null (; 9 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
  (func $exports/subOpt|trampoline (; 10 ;) (type $FUNCSIG$iii) (param $0 i32) (param $1 i32) (result i32)
   block $1of1
diff --git a/tests/compiler/exports.untouched.wat b/tests/compiler/exports.untouched.wat
index 5ad9605083..0fb60d8415 100644
--- a/tests/compiler/exports.untouched.wat
+++ b/tests/compiler/exports.untouched.wat
@@ -254,6 +254,7 @@
   global.set $~lib/rt/stub/offset
  )
  (func $null (; 17 ;) (type $FUNCSIG$v)
+  unreachable
  )
  (func $exports/subOpt|trampoline (; 18 ;) (type $FUNCSIG$iii) (param $0 i32) (param $1 i32) (result i32)
   block $1of1
diff --git a/tests/compiler/external.optimized.wat b/tests/compiler/external.optimized.wat
index 3cd8fa2698..579af7c466 100644
--- a/tests/compiler/external.optimized.wat
+++ b/tests/compiler/external.optimized.wat
@@ -13,6 +13,6 @@
  (export "three" (func $external/three))
  (export "var_" (global $external/var_))
  (func $null (; 4 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/external.untouched.wat b/tests/compiler/external.untouched.wat
index 664061dcc0..6a53973278 100644
--- a/tests/compiler/external.untouched.wat
+++ b/tests/compiler/external.untouched.wat
@@ -15,5 +15,6 @@
  (export "three" (func $external/three))
  (export "var_" (global $external/var_))
  (func $null (; 4 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/features/exception-handling.js b/tests/compiler/features/exception-handling.js
new file mode 100644
index 0000000000..bb10ece3a0
--- /dev/null
+++ b/tests/compiler/features/exception-handling.js
@@ -0,0 +1,8 @@
+const assert = require('assert');
+
+exports.postInstantiate = function (instance) {
+  const exports = instance.exports;
+  assert.throws(() => {
+    exports.testNullFunction();
+  }, /^RuntimeError: wasm exception$/);
+};
diff --git a/tests/compiler/features/exception-handling.json b/tests/compiler/features/exception-handling.json
new file mode 100644
index 0000000000..a542b9dff9
--- /dev/null
+++ b/tests/compiler/features/exception-handling.json
@@ -0,0 +1,8 @@
+{
+  "features": [
+    "exception-handling"
+  ],
+  "asc_flags": [
+    "--runtime none"
+  ]
+}
diff --git a/tests/compiler/features/exception-handling.optimized.wat b/tests/compiler/features/exception-handling.optimized.wat
new file mode 100644
index 0000000000..61859094b7
--- /dev/null
+++ b/tests/compiler/features/exception-handling.optimized.wat
@@ -0,0 +1,24 @@
+(module
+ (type $FUNCSIG$v (func))
+ (type $NullPointerException (func (param i32)))
+ (memory $0 1)
+ (data (i32.const 8) ",\00\00\00\01\00\00\00\01\00\00\00,\00\00\00n\00u\00l\00l\00 \00i\00s\00 \00n\00o\00t\00 \00a\00 \00f\00u\00n\00c\00t\00i\00o\00n")
+ (table $0 2 funcref)
+ (elem (i32.const 0) $null $features/exception-handling/testNullable~anonymous|0)
+ (global $~lib/argc (mut i32) (i32.const 0))
+ (event $NullPointerException (attr 0) (param i32))
+ (export "memory" (memory $0))
+ (export "testNullFunction" (func $features/exception-handling/testNullFunction))
+ (func $features/exception-handling/testNullable~anonymous|0 (; 0 ;) (type $FUNCSIG$v)
+  nop
+ )
+ (func $features/exception-handling/testNullFunction (; 1 ;) (type $FUNCSIG$v)
+  i32.const 0
+  global.set $~lib/argc
+  call $null
+ )
+ (func $null (; 2 ;) (type $FUNCSIG$v)
+  i32.const 24
+  throw $NullPointerException
+ )
+)
diff --git a/tests/compiler/features/exception-handling.ts b/tests/compiler/features/exception-handling.ts
new file mode 100644
index 0000000000..b2ed65ae72
--- /dev/null
+++ b/tests/compiler/features/exception-handling.ts
@@ -0,0 +1,12 @@
+function testNullable(b: boolean): (() => void) | null {
+  if (b) {
+    return (): void => { };
+  } else {
+    return null;
+  }
+}
+
+export function testNullFunction(): void {
+  var fn = testNullable(false) as () => void;
+  fn();
+}
diff --git a/tests/compiler/features/exception-handling.untouched.wat b/tests/compiler/features/exception-handling.untouched.wat
new file mode 100644
index 0000000000..c73a343f98
--- /dev/null
+++ b/tests/compiler/features/exception-handling.untouched.wat
@@ -0,0 +1,41 @@
+(module
+ (type $FUNCSIG$v (func))
+ (type $FUNCSIG$ii (func (param i32) (result i32)))
+ (type $NullPointerException (func (param i32)))
+ (memory $0 1)
+ (data (i32.const 8) ",\00\00\00\01\00\00\00\01\00\00\00,\00\00\00n\00u\00l\00l\00 \00i\00s\00 \00n\00o\00t\00 \00a\00 \00f\00u\00n\00c\00t\00i\00o\00n\00")
+ (table $0 2 funcref)
+ (elem (i32.const 0) $null $features/exception-handling/testNullable~anonymous|0)
+ (global $~lib/argc (mut i32) (i32.const 0))
+ (event $NullPointerException (attr 0) (param i32))
+ (export "memory" (memory $0))
+ (export "testNullFunction" (func $features/exception-handling/testNullFunction))
+ (func $features/exception-handling/testNullable~anonymous|0 (; 0 ;) (type $FUNCSIG$v)
+  nop
+ )
+ (func $features/exception-handling/testNullable (; 1 ;) (type $FUNCSIG$ii) (param $0 i32) (result i32)
+  local.get $0
+  if
+   i32.const 1
+   return
+  else
+   i32.const 0
+   return
+  end
+  unreachable
+ )
+ (func $features/exception-handling/testNullFunction (; 2 ;) (type $FUNCSIG$v)
+  (local $0 i32)
+  i32.const 0
+  call $features/exception-handling/testNullable
+  local.set $0
+  i32.const 0
+  global.set $~lib/argc
+  local.get $0
+  call_indirect (type $FUNCSIG$v)
+ )
+ (func $null (; 3 ;) (type $FUNCSIG$v)
+  i32.const 24
+  throw $NullPointerException
+ )
+)
diff --git a/tests/compiler/features/js-bigint-integration.optimized.wat b/tests/compiler/features/js-bigint-integration.optimized.wat
index 19a493b0f8..41ec08cf19 100644
--- a/tests/compiler/features/js-bigint-integration.optimized.wat
+++ b/tests/compiler/features/js-bigint-integration.optimized.wat
@@ -51,6 +51,6 @@
   call $start:features/js-bigint-integration
  )
  (func $null (; 5 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/features/js-bigint-integration.untouched.wat b/tests/compiler/features/js-bigint-integration.untouched.wat
index 2f35cfdf80..addf041758 100644
--- a/tests/compiler/features/js-bigint-integration.untouched.wat
+++ b/tests/compiler/features/js-bigint-integration.untouched.wat
@@ -55,5 +55,6 @@
   call $start:features/js-bigint-integration
  )
  (func $null (; 5 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/features/mutable-globals.optimized.wat b/tests/compiler/features/mutable-globals.optimized.wat
index f3a3bcfc37..e20e932a56 100644
--- a/tests/compiler/features/mutable-globals.optimized.wat
+++ b/tests/compiler/features/mutable-globals.optimized.wat
@@ -76,6 +76,6 @@
   call $start:features/mutable-globals
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/features/mutable-globals.untouched.wat b/tests/compiler/features/mutable-globals.untouched.wat
index 87e54656c6..8da74ea634 100644
--- a/tests/compiler/features/mutable-globals.untouched.wat
+++ b/tests/compiler/features/mutable-globals.untouched.wat
@@ -82,5 +82,6 @@
   call $start:features/mutable-globals
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/features/reference-types.optimized.wat b/tests/compiler/features/reference-types.optimized.wat
index cf8faebb89..89fc5e79e7 100644
--- a/tests/compiler/features/reference-types.optimized.wat
+++ b/tests/compiler/features/reference-types.optimized.wat
@@ -26,7 +26,7 @@
   if
    i32.const 0
    i32.const 24
-   i32.const 16
+   i32.const 19
    i32.const 0
    call $~lib/builtins/abort
    unreachable
@@ -42,11 +42,14 @@
  )
  (func $features/reference-types/internal (; 6 ;) (type $FUNCSIG$aa) (param $0 anyref) (result anyref)
   local.get $0
+  call $features/reference-types/external
+  call $features/reference-types/external
+  call $features/reference-types/external
  )
  (func $start (; 7 ;) (type $FUNCSIG$v)
   call $start:features/reference-types
  )
  (func $null (; 8 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/features/reference-types.untouched.wat b/tests/compiler/features/reference-types.untouched.wat
index b73dd87ff1..459aef8ed4 100644
--- a/tests/compiler/features/reference-types.untouched.wat
+++ b/tests/compiler/features/reference-types.untouched.wat
@@ -63,5 +63,6 @@
   call $start:features/reference-types
  )
  (func $null (; 8 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/features/simd.untouched.wat b/tests/compiler/features/simd.untouched.wat
index d396081140..41477e3c3b 100644
--- a/tests/compiler/features/simd.untouched.wat
+++ b/tests/compiler/features/simd.untouched.wat
@@ -2299,5 +2299,6 @@
   call $start:features/simd
  )
  (func $null (; 17 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/features/threads.optimized.wat b/tests/compiler/features/threads.optimized.wat
index 297be93949..b819f8a04d 100644
--- a/tests/compiler/features/threads.optimized.wat
+++ b/tests/compiler/features/threads.optimized.wat
@@ -537,6 +537,6 @@
   call $features/threads/testAtomicAsm
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/features/threads.untouched.wat b/tests/compiler/features/threads.untouched.wat
index 71e08b8314..672aba15a0 100644
--- a/tests/compiler/features/threads.untouched.wat
+++ b/tests/compiler/features/threads.untouched.wat
@@ -543,5 +543,6 @@
   call $start:features/threads
  )
  (func $null (; 4 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/for.optimized.wat b/tests/compiler/for.optimized.wat
index 39454bff39..bd0aa8e1c9 100644
--- a/tests/compiler/for.optimized.wat
+++ b/tests/compiler/for.optimized.wat
@@ -159,6 +159,6 @@
   call $start:for
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/for.untouched.wat b/tests/compiler/for.untouched.wat
index dad71958a2..c638bd6edc 100644
--- a/tests/compiler/for.untouched.wat
+++ b/tests/compiler/for.untouched.wat
@@ -199,5 +199,6 @@
   call $start:for
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/function-expression.js b/tests/compiler/function-expression.js
new file mode 100644
index 0000000000..4ddd6fc2ac
--- /dev/null
+++ b/tests/compiler/function-expression.js
@@ -0,0 +1,6 @@
+const assert = require('assert');
+
+exports.postInstantiate = function (instance) {
+  const exports = instance.exports;
+  assert.throws(exports.testNullFunction, /^RuntimeError: unreachable$/);
+};
diff --git a/tests/compiler/function-expression.optimized.wat b/tests/compiler/function-expression.optimized.wat
index fdeb8b08d0..7cc49ab847 100644
--- a/tests/compiler/function-expression.optimized.wat
+++ b/tests/compiler/function-expression.optimized.wat
@@ -8,9 +8,10 @@
  (memory $0 1)
  (data (i32.const 8) ",\00\00\00\01\00\00\00\01\00\00\00,\00\00\00f\00u\00n\00c\00t\00i\00o\00n\00-\00e\00x\00p\00r\00e\00s\00s\00i\00o\00n\00.\00t\00s")
  (table $0 12 funcref)
- (elem (i32.const 0) $start:function-expression~someName $start:function-expression~anonymous|0 $start:function-expression~anonymous|0 $start:function-expression~someName $start:function-expression~anonymous|2 $start:function-expression~anonymous|3 $start:function-expression~anonymous|4 $start:function-expression~anonymous|5 $start:function-expression~anonymous|3 $start:function-expression~anonymous|4 $start:function-expression~anonymous|5 $start:function-expression~anonymous|2)
+ (elem (i32.const 0) $null $start:function-expression~anonymous|0 $start:function-expression~anonymous|0 $start:function-expression~someName $start:function-expression~anonymous|2 $start:function-expression~anonymous|3 $start:function-expression~anonymous|4 $start:function-expression~anonymous|5 $start:function-expression~anonymous|3 $start:function-expression~anonymous|4 $start:function-expression~anonymous|5 $start:function-expression~someName)
  (global $~lib/argc (mut i32) (i32.const 0))
  (export "memory" (memory $0))
+ (export "testNullFunction" (func $function-expression/testNullFunction))
  (start $start)
  (func $start:function-expression~anonymous|0 (; 1 ;) (type $FUNCSIG$ii) (param $0 i32) (result i32)
   local.get $0
@@ -167,7 +168,15 @@
    unreachable
   end
  )
- (func $start (; 9 ;) (type $FUNCSIG$v)
+ (func $function-expression/testNullFunction (; 9 ;) (type $FUNCSIG$v)
+  i32.const 0
+  global.set $~lib/argc
+  call $null
+ )
+ (func $start (; 10 ;) (type $FUNCSIG$v)
   call $start:function-expression
  )
+ (func $null (; 11 ;) (type $FUNCSIG$v)
+  unreachable
+ )
 )
diff --git a/tests/compiler/function-expression.ts b/tests/compiler/function-expression.ts
index 294eaee7bf..6de9a88453 100644
--- a/tests/compiler/function-expression.ts
+++ b/tests/compiler/function-expression.ts
@@ -35,11 +35,16 @@ assert(testOmittedReturn1()(1, 2) == 3);
 assert(testOmittedReturn2()(1, 2) == 1);
 assert(testOmittedReturn3()(1, 2) == 42);
 
-function testNullable(b: boolean): (() => i32) | null {
+function testNullable(b: boolean): (() => void) | null {
   if (b) {
-    return (): i32 => 1;
+    return (): void => { };
   } else {
     return null;
   }
 }
 assert(testNullable(false) == null);
+
+export function testNullFunction(): void {
+  var fn = testNullable(false) as () => void;
+  fn();
+}
\ No newline at end of file
diff --git a/tests/compiler/function-expression.untouched.wat b/tests/compiler/function-expression.untouched.wat
index a33e1cb206..a06ba2d0ff 100644
--- a/tests/compiler/function-expression.untouched.wat
+++ b/tests/compiler/function-expression.untouched.wat
@@ -15,6 +15,7 @@
  (global $function-expression/f3 (mut i32) (i32.const 3))
  (global $function-expression/f4 (mut i32) (i32.const 4))
  (export "memory" (memory $0))
+ (export "testNullFunction" (func $function-expression/testNullFunction))
  (start $start)
  (func $start:function-expression~anonymous|0 (; 1 ;) (type $FUNCSIG$ii) (param $0 i32) (result i32)
   local.get $0
@@ -67,8 +68,8 @@
  (func $function-expression/testOmittedReturn3 (; 14 ;) (type $FUNCSIG$i) (result i32)
   i32.const 10
  )
- (func $function-expression/testNullable~anonymous|0 (; 15 ;) (type $FUNCSIG$i) (result i32)
-  i32.const 1
+ (func $function-expression/testNullable~anonymous|0 (; 15 ;) (type $FUNCSIG$v)
+  nop
  )
  (func $function-expression/testNullable (; 16 ;) (type $FUNCSIG$ii) (param $0 i32) (result i32)
   local.get $0
@@ -237,9 +238,20 @@
    unreachable
   end
  )
- (func $start (; 18 ;) (type $FUNCSIG$v)
+ (func $function-expression/testNullFunction (; 18 ;) (type $FUNCSIG$v)
+  (local $0 i32)
+  i32.const 0
+  call $function-expression/testNullable
+  local.set $0
+  i32.const 0
+  global.set $~lib/argc
+  local.get $0
+  call_indirect (type $FUNCSIG$v)
+ )
+ (func $start (; 19 ;) (type $FUNCSIG$v)
   call $start:function-expression
  )
- (func $null (; 19 ;) (type $FUNCSIG$v)
+ (func $null (; 20 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/function-types.optimized.wat b/tests/compiler/function-types.optimized.wat
index 5db5e9cadf..e3eeae9859 100644
--- a/tests/compiler/function-types.optimized.wat
+++ b/tests/compiler/function-types.optimized.wat
@@ -166,6 +166,6 @@
   call $start:function-types
  )
  (func $null (; 7 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/function-types.untouched.wat b/tests/compiler/function-types.untouched.wat
index 62d37d5c86..c19f81712c 100644
--- a/tests/compiler/function-types.untouched.wat
+++ b/tests/compiler/function-types.untouched.wat
@@ -225,5 +225,6 @@
   call $start:function-types
  )
  (func $null (; 14 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/function.optimized.wat b/tests/compiler/function.optimized.wat
index e2acb0a3b8..8a6433fd8c 100644
--- a/tests/compiler/function.optimized.wat
+++ b/tests/compiler/function.optimized.wat
@@ -2,7 +2,7 @@
  (type $FUNCSIG$v (func))
  (memory $0 0)
  (export "memory" (memory $0))
- (func $start (; 0 ;) (type $FUNCSIG$v)
-  nop
+ (func $null (; 0 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/function.untouched.wat b/tests/compiler/function.untouched.wat
index 1e51a1fe49..e8d72d0883 100644
--- a/tests/compiler/function.untouched.wat
+++ b/tests/compiler/function.untouched.wat
@@ -136,5 +136,6 @@
   call $start:function
  )
  (func $null (; 20 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/getter-call.optimized.wat b/tests/compiler/getter-call.optimized.wat
index 9b0b82a4ff..83161358be 100644
--- a/tests/compiler/getter-call.optimized.wat
+++ b/tests/compiler/getter-call.optimized.wat
@@ -97,6 +97,6 @@
   global.set $~lib/rt/stub/offset
  )
  (func $null (; 5 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/getter-call.untouched.wat b/tests/compiler/getter-call.untouched.wat
index 9bd7e0e965..b9b04a08cc 100644
--- a/tests/compiler/getter-call.untouched.wat
+++ b/tests/compiler/getter-call.untouched.wat
@@ -174,5 +174,6 @@
   global.set $~lib/rt/stub/offset
  )
  (func $null (; 9 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/getter-setter.optimized.wat b/tests/compiler/getter-setter.optimized.wat
index a3928a12c0..0327fc4fd4 100644
--- a/tests/compiler/getter-setter.optimized.wat
+++ b/tests/compiler/getter-setter.optimized.wat
@@ -26,6 +26,6 @@
   call $start:getter-setter
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/getter-setter.untouched.wat b/tests/compiler/getter-setter.untouched.wat
index a31ef8ab61..acb94ff79c 100644
--- a/tests/compiler/getter-setter.untouched.wat
+++ b/tests/compiler/getter-setter.untouched.wat
@@ -64,5 +64,6 @@
   call $start:getter-setter
  )
  (func $null (; 5 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/i64-polyfill.optimized.wat b/tests/compiler/i64-polyfill.optimized.wat
index 72d4e59b09..78f008c1bd 100644
--- a/tests/compiler/i64-polyfill.optimized.wat
+++ b/tests/compiler/i64-polyfill.optimized.wat
@@ -94,8 +94,7 @@
   i64.const 32
   i64.shl
   i64.or
-  i64.const 0
-  i64.eq
+  i64.eqz
   global.set $../../lib/i64/assembly/i64/lo
   i32.const 0
   global.set $../../lib/i64/assembly/i64/hi
@@ -691,6 +690,6 @@
   global.set $../../lib/i64/assembly/i64/hi
  )
  (func $null (; 31 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/i64-polyfill.untouched.wat b/tests/compiler/i64-polyfill.untouched.wat
index 03eeae0d66..84c8906b6b 100644
--- a/tests/compiler/i64-polyfill.untouched.wat
+++ b/tests/compiler/i64-polyfill.untouched.wat
@@ -751,5 +751,6 @@
   global.set $../../lib/i64/assembly/i64/hi
  )
  (func $null (; 31 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/if.optimized.wat b/tests/compiler/if.optimized.wat
index 94c0a353c6..d1b22fd05c 100644
--- a/tests/compiler/if.optimized.wat
+++ b/tests/compiler/if.optimized.wat
@@ -111,6 +111,6 @@
   call $start:if
  )
  (func $null (; 6 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/if.untouched.wat b/tests/compiler/if.untouched.wat
index 5552ea42f2..b3f09c11b8 100644
--- a/tests/compiler/if.untouched.wat
+++ b/tests/compiler/if.untouched.wat
@@ -143,5 +143,6 @@
   call $start:if
  )
  (func $null (; 7 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/import.optimized.wat b/tests/compiler/import.optimized.wat
index e2acb0a3b8..8a6433fd8c 100644
--- a/tests/compiler/import.optimized.wat
+++ b/tests/compiler/import.optimized.wat
@@ -2,7 +2,7 @@
  (type $FUNCSIG$v (func))
  (memory $0 0)
  (export "memory" (memory $0))
- (func $start (; 0 ;) (type $FUNCSIG$v)
-  nop
+ (func $null (; 0 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/import.untouched.wat b/tests/compiler/import.untouched.wat
index e47595b19f..b1e14d5b08 100644
--- a/tests/compiler/import.untouched.wat
+++ b/tests/compiler/import.untouched.wat
@@ -64,5 +64,6 @@
   call $start:import
  )
  (func $null (; 7 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/indexof-valueof.optimized.wat b/tests/compiler/indexof-valueof.optimized.wat
index bb456a1172..8a6433fd8c 100644
--- a/tests/compiler/indexof-valueof.optimized.wat
+++ b/tests/compiler/indexof-valueof.optimized.wat
@@ -3,6 +3,6 @@
  (memory $0 0)
  (export "memory" (memory $0))
  (func $null (; 0 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/indexof-valueof.untouched.wat b/tests/compiler/indexof-valueof.untouched.wat
index 29ee81b836..6cdcf09d9b 100644
--- a/tests/compiler/indexof-valueof.untouched.wat
+++ b/tests/compiler/indexof-valueof.untouched.wat
@@ -5,5 +5,6 @@
  (elem (i32.const 0) $null)
  (export "memory" (memory $0))
  (func $null (; 0 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/infer-generic.optimized.wat b/tests/compiler/infer-generic.optimized.wat
index 8da77f7349..8722799d1e 100644
--- a/tests/compiler/infer-generic.optimized.wat
+++ b/tests/compiler/infer-generic.optimized.wat
@@ -76,6 +76,6 @@
   call $~lib/array/Array<f32>#reduce<bool>
  )
  (func $null (; 5 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/infer-generic.untouched.wat b/tests/compiler/infer-generic.untouched.wat
index 296df99d33..f0ac21bd35 100644
--- a/tests/compiler/infer-generic.untouched.wat
+++ b/tests/compiler/infer-generic.untouched.wat
@@ -168,5 +168,6 @@
   call $start:infer-generic
  )
  (func $null (; 16 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/infer-type.optimized.wat b/tests/compiler/infer-type.optimized.wat
index e95f5f935c..b47b35c2fc 100644
--- a/tests/compiler/infer-type.optimized.wat
+++ b/tests/compiler/infer-type.optimized.wat
@@ -34,6 +34,6 @@
   call $start:infer-type
  )
  (func $null (; 2 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/infer-type.untouched.wat b/tests/compiler/infer-type.untouched.wat
index fea4b10325..173723ae32 100644
--- a/tests/compiler/infer-type.untouched.wat
+++ b/tests/compiler/infer-type.untouched.wat
@@ -100,5 +100,6 @@
   call $start:infer-type
  )
  (func $null (; 7 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/inlining-blocklocals.optimized.wat b/tests/compiler/inlining-blocklocals.optimized.wat
index eab3e0f06d..abee3a8b7e 100644
--- a/tests/compiler/inlining-blocklocals.optimized.wat
+++ b/tests/compiler/inlining-blocklocals.optimized.wat
@@ -50,6 +50,6 @@
   call $inlining-blocklocals/test
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/inlining-blocklocals.untouched.wat b/tests/compiler/inlining-blocklocals.untouched.wat
index 6330ed8b87..b26f1e6cec 100644
--- a/tests/compiler/inlining-blocklocals.untouched.wat
+++ b/tests/compiler/inlining-blocklocals.untouched.wat
@@ -100,5 +100,6 @@
   call $start:inlining-blocklocals
  )
  (func $null (; 4 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/inlining-recursive.optimized.wat b/tests/compiler/inlining-recursive.optimized.wat
index d75cc7c9bd..8c74375ee6 100644
--- a/tests/compiler/inlining-recursive.optimized.wat
+++ b/tests/compiler/inlining-recursive.optimized.wat
@@ -12,6 +12,6 @@
   call $inlining-recursive/baz
  )
  (func $null (; 2 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/inlining-recursive.untouched.wat b/tests/compiler/inlining-recursive.untouched.wat
index 4cc3e73c26..667e92f75f 100644
--- a/tests/compiler/inlining-recursive.untouched.wat
+++ b/tests/compiler/inlining-recursive.untouched.wat
@@ -17,5 +17,6 @@
   call $inlining-recursive/baz
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/inlining.optimized.wat b/tests/compiler/inlining.optimized.wat
index 833540bcfb..46740eed77 100644
--- a/tests/compiler/inlining.optimized.wat
+++ b/tests/compiler/inlining.optimized.wat
@@ -214,6 +214,6 @@
   call $inlining/test_ctor
  )
  (func $null (; 8 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/inlining.untouched.wat b/tests/compiler/inlining.untouched.wat
index b4ccbd2366..0d04bdf2fd 100644
--- a/tests/compiler/inlining.untouched.wat
+++ b/tests/compiler/inlining.untouched.wat
@@ -520,5 +520,6 @@
   call $start:inlining
  )
  (func $null (; 11 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/instanceof.optimized.wat b/tests/compiler/instanceof.optimized.wat
index 474ae7b02f..ff9ca7abb8 100644
--- a/tests/compiler/instanceof.optimized.wat
+++ b/tests/compiler/instanceof.optimized.wat
@@ -24,6 +24,6 @@
   call $start:instanceof
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/instanceof.untouched.wat b/tests/compiler/instanceof.untouched.wat
index 4117c6a6e3..eb9ec927c0 100644
--- a/tests/compiler/instanceof.untouched.wat
+++ b/tests/compiler/instanceof.untouched.wat
@@ -134,5 +134,6 @@
   call $start:instanceof
  )
  (func $null (; 9 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/limits.optimized.wat b/tests/compiler/limits.optimized.wat
index e2acb0a3b8..8a6433fd8c 100644
--- a/tests/compiler/limits.optimized.wat
+++ b/tests/compiler/limits.optimized.wat
@@ -2,7 +2,7 @@
  (type $FUNCSIG$v (func))
  (memory $0 0)
  (export "memory" (memory $0))
- (func $start (; 0 ;) (type $FUNCSIG$v)
-  nop
+ (func $null (; 0 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/limits.untouched.wat b/tests/compiler/limits.untouched.wat
index 73017341a9..9e0eaa9480 100644
--- a/tests/compiler/limits.untouched.wat
+++ b/tests/compiler/limits.untouched.wat
@@ -89,5 +89,6 @@
   call $start:limits
  )
  (func $null (; 2 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/literals.optimized.wat b/tests/compiler/literals.optimized.wat
index e2acb0a3b8..8a6433fd8c 100644
--- a/tests/compiler/literals.optimized.wat
+++ b/tests/compiler/literals.optimized.wat
@@ -2,7 +2,7 @@
  (type $FUNCSIG$v (func))
  (memory $0 0)
  (export "memory" (memory $0))
- (func $start (; 0 ;) (type $FUNCSIG$v)
-  nop
+ (func $null (; 0 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/literals.untouched.wat b/tests/compiler/literals.untouched.wat
index 947b448255..01de665726 100644
--- a/tests/compiler/literals.untouched.wat
+++ b/tests/compiler/literals.untouched.wat
@@ -99,5 +99,6 @@
   call $start:literals
  )
  (func $null (; 2 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/logical.optimized.wat b/tests/compiler/logical.optimized.wat
index 57ae1147b4..6b13201914 100644
--- a/tests/compiler/logical.optimized.wat
+++ b/tests/compiler/logical.optimized.wat
@@ -98,6 +98,6 @@
   call $start:logical
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/logical.untouched.wat b/tests/compiler/logical.untouched.wat
index f00be19eb6..e5d8c1bfba 100644
--- a/tests/compiler/logical.untouched.wat
+++ b/tests/compiler/logical.untouched.wat
@@ -496,5 +496,6 @@
   call $start:logical
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/loop-flow.optimized.wat b/tests/compiler/loop-flow.optimized.wat
index 0b408ca64d..269ba340d6 100644
--- a/tests/compiler/loop-flow.optimized.wat
+++ b/tests/compiler/loop-flow.optimized.wat
@@ -160,6 +160,6 @@
   call $start:loop-flow
  )
  (func $null (; 11 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/loop-flow.untouched.wat b/tests/compiler/loop-flow.untouched.wat
index b25256d9e6..91c163ce37 100644
--- a/tests/compiler/loop-flow.untouched.wat
+++ b/tests/compiler/loop-flow.untouched.wat
@@ -238,5 +238,6 @@
   call $start:loop-flow
  )
  (func $null (; 14 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/loop-wrap.optimized.wat b/tests/compiler/loop-wrap.optimized.wat
index 16f3053b10..896cbb2bc5 100644
--- a/tests/compiler/loop-wrap.optimized.wat
+++ b/tests/compiler/loop-wrap.optimized.wat
@@ -61,6 +61,6 @@
   end
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/loop-wrap.untouched.wat b/tests/compiler/loop-wrap.untouched.wat
index db3a161eee..8b68a9a753 100644
--- a/tests/compiler/loop-wrap.untouched.wat
+++ b/tests/compiler/loop-wrap.untouched.wat
@@ -79,5 +79,6 @@
   end
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/mandelbrot.optimized.wat b/tests/compiler/mandelbrot.optimized.wat
index 4ab4872752..27615ecc0f 100644
--- a/tests/compiler/mandelbrot.optimized.wat
+++ b/tests/compiler/mandelbrot.optimized.wat
@@ -32,8 +32,7 @@
    local.get $2
    i64.const 1
    i64.shl
-   i64.const 0
-   i64.eq
+   i64.eqz
    if
     f64.const -1
     local.get $0
@@ -75,8 +74,7 @@
     local.get $2
     i64.const 32
     i64.shl
-    i64.const 0
-    i64.eq
+    i64.eqz
     i32.const 0
     local.get $1
     i32.const 1072693248
@@ -203,8 +201,7 @@
    local.get $3
    i64.const 1
    i64.shl
-   i64.const 0
-   i64.eq
+   i64.eqz
    if
     f64.const -1
     local.get $0
@@ -246,8 +243,7 @@
     local.get $3
     i64.const 32
     i64.shl
-    i64.const 0
-    i64.eq
+    i64.eqz
     i32.const 0
     local.get $2
     i32.const 1072693248
@@ -575,6 +571,6 @@
   end
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/mandelbrot.untouched.wat b/tests/compiler/mandelbrot.untouched.wat
index f86ef4925d..529fa32ac9 100644
--- a/tests/compiler/mandelbrot.untouched.wat
+++ b/tests/compiler/mandelbrot.untouched.wat
@@ -718,5 +718,6 @@
   end
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/many-locals.optimized.wat b/tests/compiler/many-locals.optimized.wat
index 7722178879..196ffc96c0 100644
--- a/tests/compiler/many-locals.optimized.wat
+++ b/tests/compiler/many-locals.optimized.wat
@@ -34,6 +34,6 @@
   end
  )
  (func $null (; 4 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/many-locals.untouched.wat b/tests/compiler/many-locals.untouched.wat
index 89dbe39434..54eb38d179 100644
--- a/tests/compiler/many-locals.untouched.wat
+++ b/tests/compiler/many-locals.untouched.wat
@@ -821,5 +821,6 @@
   call $start:many-locals
  )
  (func $null (; 5 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/memcpy.optimized.wat b/tests/compiler/memcpy.optimized.wat
index 80e86c861a..45600c5b9e 100644
--- a/tests/compiler/memcpy.optimized.wat
+++ b/tests/compiler/memcpy.optimized.wat
@@ -1045,6 +1045,6 @@
   call $start:memcpy
  )
  (func $null (; 4 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/memcpy.untouched.wat b/tests/compiler/memcpy.untouched.wat
index a99611db2e..038fc7e7cb 100644
--- a/tests/compiler/memcpy.untouched.wat
+++ b/tests/compiler/memcpy.untouched.wat
@@ -1255,5 +1255,6 @@
   call $start:memcpy
  )
  (func $null (; 4 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/memmove.optimized.wat b/tests/compiler/memmove.optimized.wat
index 7ca42ad13b..b644f2fc4c 100644
--- a/tests/compiler/memmove.optimized.wat
+++ b/tests/compiler/memmove.optimized.wat
@@ -374,6 +374,6 @@
   call $start:memmove
  )
  (func $null (; 4 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/memmove.untouched.wat b/tests/compiler/memmove.untouched.wat
index b85249d745..49a25ab665 100644
--- a/tests/compiler/memmove.untouched.wat
+++ b/tests/compiler/memmove.untouched.wat
@@ -421,5 +421,6 @@
   call $start:memmove
  )
  (func $null (; 4 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/memset.optimized.wat b/tests/compiler/memset.optimized.wat
index d062bff123..3d2c0d48e5 100644
--- a/tests/compiler/memset.optimized.wat
+++ b/tests/compiler/memset.optimized.wat
@@ -329,6 +329,6 @@
   call $start:memset
  )
  (func $null (; 4 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/memset.untouched.wat b/tests/compiler/memset.untouched.wat
index f4d16e28b7..34dadb840a 100644
--- a/tests/compiler/memset.untouched.wat
+++ b/tests/compiler/memset.untouched.wat
@@ -380,5 +380,6 @@
   call $start:memset
  )
  (func $null (; 4 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/merge.optimized.wat b/tests/compiler/merge.optimized.wat
index e2acb0a3b8..8a6433fd8c 100644
--- a/tests/compiler/merge.optimized.wat
+++ b/tests/compiler/merge.optimized.wat
@@ -2,7 +2,7 @@
  (type $FUNCSIG$v (func))
  (memory $0 0)
  (export "memory" (memory $0))
- (func $start (; 0 ;) (type $FUNCSIG$v)
-  nop
+ (func $null (; 0 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/merge.untouched.wat b/tests/compiler/merge.untouched.wat
index e1dceafa81..a003f9fb4d 100644
--- a/tests/compiler/merge.untouched.wat
+++ b/tests/compiler/merge.untouched.wat
@@ -93,5 +93,6 @@
   call $start:merge
  )
  (func $null (; 18 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/named-export-default.optimized.wat b/tests/compiler/named-export-default.optimized.wat
index 0886d5cce7..7280329c2f 100644
--- a/tests/compiler/named-export-default.optimized.wat
+++ b/tests/compiler/named-export-default.optimized.wat
@@ -8,6 +8,6 @@
   i32.const 3
  )
  (func $null (; 1 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/named-export-default.untouched.wat b/tests/compiler/named-export-default.untouched.wat
index 3f1ff0ab82..e31e0cd952 100644
--- a/tests/compiler/named-export-default.untouched.wat
+++ b/tests/compiler/named-export-default.untouched.wat
@@ -10,5 +10,6 @@
   i32.const 3
  )
  (func $null (; 1 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/named-import-default.optimized.wat b/tests/compiler/named-import-default.optimized.wat
index e9b05938fc..08702e8a31 100644
--- a/tests/compiler/named-import-default.optimized.wat
+++ b/tests/compiler/named-import-default.optimized.wat
@@ -8,6 +8,6 @@
   i32.const 3
  )
  (func $null (; 1 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/named-import-default.untouched.wat b/tests/compiler/named-import-default.untouched.wat
index f24ee8a33a..23c901bf80 100644
--- a/tests/compiler/named-import-default.untouched.wat
+++ b/tests/compiler/named-import-default.untouched.wat
@@ -13,5 +13,6 @@
   call $named-export-default/get3
  )
  (func $null (; 2 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/namespace.optimized.wat b/tests/compiler/namespace.optimized.wat
index 44951b0929..e48fa4f789 100644
--- a/tests/compiler/namespace.optimized.wat
+++ b/tests/compiler/namespace.optimized.wat
@@ -12,6 +12,6 @@
   global.set $namespace/Outer.Inner.evenAnotherVar
  )
  (func $null (; 1 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/namespace.untouched.wat b/tests/compiler/namespace.untouched.wat
index 9893d869ba..ab9b8af6a4 100644
--- a/tests/compiler/namespace.untouched.wat
+++ b/tests/compiler/namespace.untouched.wat
@@ -38,5 +38,6 @@
   call $start:namespace
  )
  (func $null (; 4 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/number.optimized.wat b/tests/compiler/number.optimized.wat
index c64786b514..913742956f 100644
--- a/tests/compiler/number.optimized.wat
+++ b/tests/compiler/number.optimized.wat
@@ -2161,6 +2161,6 @@
   call $start:number
  )
  (func $null (; 23 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/number.untouched.wat b/tests/compiler/number.untouched.wat
index f6eb58e06c..b67c8770f7 100644
--- a/tests/compiler/number.untouched.wat
+++ b/tests/compiler/number.untouched.wat
@@ -4229,5 +4229,6 @@
   call $start:number
  )
  (func $null (; 31 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/optional-typeparameters.optimized.wat b/tests/compiler/optional-typeparameters.optimized.wat
index 2189da8971..31bbc0695f 100644
--- a/tests/compiler/optional-typeparameters.optimized.wat
+++ b/tests/compiler/optional-typeparameters.optimized.wat
@@ -91,6 +91,6 @@
   global.set $optional-typeparameters/tDerived
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/optional-typeparameters.untouched.wat b/tests/compiler/optional-typeparameters.untouched.wat
index 0eea36ce30..bb12e80379 100644
--- a/tests/compiler/optional-typeparameters.untouched.wat
+++ b/tests/compiler/optional-typeparameters.untouched.wat
@@ -203,5 +203,6 @@
   call $start:optional-typeparameters
  )
  (func $null (; 11 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/overflow.optimized.wat b/tests/compiler/overflow.optimized.wat
index 4bc2888fd3..117ded59e2 100644
--- a/tests/compiler/overflow.optimized.wat
+++ b/tests/compiler/overflow.optimized.wat
@@ -3,7 +3,7 @@
  (memory $0 1)
  (data (i32.const 8) "\16\00\00\00\01\00\00\00\01\00\00\00\16\00\00\00o\00v\00e\00r\00f\00l\00o\00w\00.\00t\00s")
  (export "memory" (memory $0))
- (func $start (; 0 ;) (type $FUNCSIG$v)
-  nop
+ (func $null (; 0 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/overflow.untouched.wat b/tests/compiler/overflow.untouched.wat
index 9acda5bf22..062303f76b 100644
--- a/tests/compiler/overflow.untouched.wat
+++ b/tests/compiler/overflow.untouched.wat
@@ -733,5 +733,6 @@
   call $start:overflow
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/portable-conversions.optimized.wat b/tests/compiler/portable-conversions.optimized.wat
index 59de98a923..080a18aef8 100644
--- a/tests/compiler/portable-conversions.optimized.wat
+++ b/tests/compiler/portable-conversions.optimized.wat
@@ -11,6 +11,6 @@
   call $start:portable-conversions
  )
  (func $null (; 2 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/portable-conversions.untouched.wat b/tests/compiler/portable-conversions.untouched.wat
index 11f2e775c1..0e1c40785a 100644
--- a/tests/compiler/portable-conversions.untouched.wat
+++ b/tests/compiler/portable-conversions.untouched.wat
@@ -638,5 +638,6 @@
   call $start:portable-conversions
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/possibly-null.optimized.wat b/tests/compiler/possibly-null.optimized.wat
index 4af480291f..f4cc2b1566 100644
--- a/tests/compiler/possibly-null.optimized.wat
+++ b/tests/compiler/possibly-null.optimized.wat
@@ -62,6 +62,6 @@
   nop
  )
  (func $null (; 5 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/possibly-null.untouched.wat b/tests/compiler/possibly-null.untouched.wat
index 308a8fbd61..25d9565566 100644
--- a/tests/compiler/possibly-null.untouched.wat
+++ b/tests/compiler/possibly-null.untouched.wat
@@ -416,5 +416,6 @@
   call $~lib/rt/stub/__release
  )
  (func $null (; 21 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/rc/global-init.optimized.wat b/tests/compiler/rc/global-init.optimized.wat
index c171eea177..cf2615941c 100644
--- a/tests/compiler/rc/global-init.optimized.wat
+++ b/tests/compiler/rc/global-init.optimized.wat
@@ -1941,6 +1941,6 @@
   unreachable
  )
  (func $null (; 34 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/rc/global-init.untouched.wat b/tests/compiler/rc/global-init.untouched.wat
index 5a4adb3e0d..f9ade3310b 100644
--- a/tests/compiler/rc/global-init.untouched.wat
+++ b/tests/compiler/rc/global-init.untouched.wat
@@ -3466,5 +3466,6 @@
   unreachable
  )
  (func $null (; 36 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/rc/local-init.optimized.wat b/tests/compiler/rc/local-init.optimized.wat
index 02eee80e8e..e943b4522f 100644
--- a/tests/compiler/rc/local-init.optimized.wat
+++ b/tests/compiler/rc/local-init.optimized.wat
@@ -1918,6 +1918,6 @@
   unreachable
  )
  (func $null (; 33 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/rc/local-init.untouched.wat b/tests/compiler/rc/local-init.untouched.wat
index fbd090dfe0..48e9d7475f 100644
--- a/tests/compiler/rc/local-init.untouched.wat
+++ b/tests/compiler/rc/local-init.untouched.wat
@@ -3457,5 +3457,6 @@
   unreachable
  )
  (func $null (; 37 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/rc/logical-and-mismatch.optimized.wat b/tests/compiler/rc/logical-and-mismatch.optimized.wat
index 6772fcfa31..bc82f76a61 100644
--- a/tests/compiler/rc/logical-and-mismatch.optimized.wat
+++ b/tests/compiler/rc/logical-and-mismatch.optimized.wat
@@ -1961,6 +1961,6 @@
   unreachable
  )
  (func $null (; 35 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/rc/logical-and-mismatch.untouched.wat b/tests/compiler/rc/logical-and-mismatch.untouched.wat
index c77e57f058..763ae26367 100644
--- a/tests/compiler/rc/logical-and-mismatch.untouched.wat
+++ b/tests/compiler/rc/logical-and-mismatch.untouched.wat
@@ -3495,5 +3495,6 @@
   unreachable
  )
  (func $null (; 37 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/rc/logical-or-mismatch.optimized.wat b/tests/compiler/rc/logical-or-mismatch.optimized.wat
index a8fee64286..38fa7e45b0 100644
--- a/tests/compiler/rc/logical-or-mismatch.optimized.wat
+++ b/tests/compiler/rc/logical-or-mismatch.optimized.wat
@@ -1961,6 +1961,6 @@
   unreachable
  )
  (func $null (; 35 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/rc/logical-or-mismatch.untouched.wat b/tests/compiler/rc/logical-or-mismatch.untouched.wat
index 7ae7e65123..ff0d73eba4 100644
--- a/tests/compiler/rc/logical-or-mismatch.untouched.wat
+++ b/tests/compiler/rc/logical-or-mismatch.untouched.wat
@@ -3495,5 +3495,6 @@
   unreachable
  )
  (func $null (; 37 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/rc/rereturn.optimized.wat b/tests/compiler/rc/rereturn.optimized.wat
index 52e8d2592b..780e66be1e 100644
--- a/tests/compiler/rc/rereturn.optimized.wat
+++ b/tests/compiler/rc/rereturn.optimized.wat
@@ -1897,6 +1897,6 @@
   unreachable
  )
  (func $null (; 29 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/rc/rereturn.untouched.wat b/tests/compiler/rc/rereturn.untouched.wat
index 9fbacb5e3b..ce9aea62ab 100644
--- a/tests/compiler/rc/rereturn.untouched.wat
+++ b/tests/compiler/rc/rereturn.untouched.wat
@@ -3431,5 +3431,6 @@
   unreachable
  )
  (func $null (; 34 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/rc/ternary-mismatch.optimized.wat b/tests/compiler/rc/ternary-mismatch.optimized.wat
index 08ab899cf5..3a0c769c67 100644
--- a/tests/compiler/rc/ternary-mismatch.optimized.wat
+++ b/tests/compiler/rc/ternary-mismatch.optimized.wat
@@ -1953,6 +1953,6 @@
   unreachable
  )
  (func $null (; 37 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/rc/ternary-mismatch.untouched.wat b/tests/compiler/rc/ternary-mismatch.untouched.wat
index d164fcc758..3ff092adc3 100644
--- a/tests/compiler/rc/ternary-mismatch.untouched.wat
+++ b/tests/compiler/rc/ternary-mismatch.untouched.wat
@@ -3479,5 +3479,6 @@
   unreachable
  )
  (func $null (; 39 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/recursive.optimized.wat b/tests/compiler/recursive.optimized.wat
index 8be1699992..f6ea56f161 100644
--- a/tests/compiler/recursive.optimized.wat
+++ b/tests/compiler/recursive.optimized.wat
@@ -23,6 +23,6 @@
   i32.add
  )
  (func $null (; 1 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/recursive.untouched.wat b/tests/compiler/recursive.untouched.wat
index daf56987dc..437da399f1 100644
--- a/tests/compiler/recursive.untouched.wat
+++ b/tests/compiler/recursive.untouched.wat
@@ -25,5 +25,6 @@
   i32.add
  )
  (func $null (; 1 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/reexport.optimized.wat b/tests/compiler/reexport.optimized.wat
index b23b502d0a..3efbd4045b 100644
--- a/tests/compiler/reexport.optimized.wat
+++ b/tests/compiler/reexport.optimized.wat
@@ -46,4 +46,7 @@
   i32.add
   drop
  )
+ (func $null (; 5 ;) (type $FUNCSIG$v)
+  unreachable
+ )
 )
diff --git a/tests/compiler/reexport.untouched.wat b/tests/compiler/reexport.untouched.wat
index 662fe579a4..e43f0185c4 100644
--- a/tests/compiler/reexport.untouched.wat
+++ b/tests/compiler/reexport.untouched.wat
@@ -55,5 +55,6 @@
   call $start:reexport
  )
  (func $null (; 7 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/rereexport.optimized.wat b/tests/compiler/rereexport.optimized.wat
index 306f12dff1..26ece05287 100644
--- a/tests/compiler/rereexport.optimized.wat
+++ b/tests/compiler/rereexport.optimized.wat
@@ -8,7 +8,7 @@
  (export "renamed_a" (global $export/a))
  (export "renamed_b" (global $export/b))
  (export "renamed_renamed_b" (global $export/b))
- (func $start (; 0 ;) (type $FUNCSIG$v)
-  nop
+ (func $null (; 0 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/rereexport.untouched.wat b/tests/compiler/rereexport.untouched.wat
index 7f469d6e96..55d9a52a30 100644
--- a/tests/compiler/rereexport.untouched.wat
+++ b/tests/compiler/rereexport.untouched.wat
@@ -40,5 +40,6 @@
   call $start:rereexport
  )
  (func $null (; 5 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/resolve-access.optimized.wat b/tests/compiler/resolve-access.optimized.wat
index d259e1a501..42986b1239 100644
--- a/tests/compiler/resolve-access.optimized.wat
+++ b/tests/compiler/resolve-access.optimized.wat
@@ -485,8 +485,7 @@
   (local $2 i32)
   (local $3 i32)
   local.get $0
-  i64.const 0
-  i64.eq
+  i64.eqz
   if
    i32.const 152
    return
@@ -588,6 +587,6 @@
   global.set $~lib/rt/stub/offset
  )
  (func $null (; 17 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/resolve-access.untouched.wat b/tests/compiler/resolve-access.untouched.wat
index 24f25c3c86..ee340d91f5 100644
--- a/tests/compiler/resolve-access.untouched.wat
+++ b/tests/compiler/resolve-access.untouched.wat
@@ -2082,5 +2082,6 @@
   global.set $~lib/rt/stub/offset
  )
  (func $null (; 26 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/resolve-binary.optimized.wat b/tests/compiler/resolve-binary.optimized.wat
index 6fbb8880aa..3c28d418b1 100644
--- a/tests/compiler/resolve-binary.optimized.wat
+++ b/tests/compiler/resolve-binary.optimized.wat
@@ -2435,6 +2435,6 @@
   call $start:resolve-binary
  )
  (func $null (; 21 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/resolve-binary.untouched.wat b/tests/compiler/resolve-binary.untouched.wat
index f5ae54ecb1..658d4afeb0 100644
--- a/tests/compiler/resolve-binary.untouched.wat
+++ b/tests/compiler/resolve-binary.untouched.wat
@@ -5807,5 +5807,6 @@
   call $start:resolve-binary
  )
  (func $null (; 46 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/resolve-elementaccess.optimized.wat b/tests/compiler/resolve-elementaccess.optimized.wat
index 43b8352ec0..2af6a306a3 100644
--- a/tests/compiler/resolve-elementaccess.optimized.wat
+++ b/tests/compiler/resolve-elementaccess.optimized.wat
@@ -1837,6 +1837,6 @@
   call $start:resolve-elementaccess
  )
  (func $null (; 22 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/resolve-elementaccess.untouched.wat b/tests/compiler/resolve-elementaccess.untouched.wat
index 0f1c0d6059..406a5646a1 100644
--- a/tests/compiler/resolve-elementaccess.untouched.wat
+++ b/tests/compiler/resolve-elementaccess.untouched.wat
@@ -3830,5 +3830,6 @@
   call $start:resolve-elementaccess
  )
  (func $null (; 28 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/resolve-function-expression.optimized.wat b/tests/compiler/resolve-function-expression.optimized.wat
index e1ef43255a..3765501821 100644
--- a/tests/compiler/resolve-function-expression.optimized.wat
+++ b/tests/compiler/resolve-function-expression.optimized.wat
@@ -404,6 +404,6 @@
   call $start:resolve-function-expression
  )
  (func $null (; 14 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/resolve-function-expression.untouched.wat b/tests/compiler/resolve-function-expression.untouched.wat
index 66b4fd0668..db9cc6fbcb 100644
--- a/tests/compiler/resolve-function-expression.untouched.wat
+++ b/tests/compiler/resolve-function-expression.untouched.wat
@@ -692,5 +692,6 @@
   call $start:resolve-function-expression
  )
  (func $null (; 18 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/resolve-nested.optimized.wat b/tests/compiler/resolve-nested.optimized.wat
index cf51f7ae97..c0f2b97fdd 100644
--- a/tests/compiler/resolve-nested.optimized.wat
+++ b/tests/compiler/resolve-nested.optimized.wat
@@ -22,6 +22,6 @@
   nop
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/resolve-nested.untouched.wat b/tests/compiler/resolve-nested.untouched.wat
index 08e34bd69a..e09a1334d8 100644
--- a/tests/compiler/resolve-nested.untouched.wat
+++ b/tests/compiler/resolve-nested.untouched.wat
@@ -113,5 +113,6 @@
   call $~lib/rt/stub/__release
  )
  (func $null (; 5 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/resolve-new.optimized.wat b/tests/compiler/resolve-new.optimized.wat
index 7a0a791c2f..01048edb72 100644
--- a/tests/compiler/resolve-new.optimized.wat
+++ b/tests/compiler/resolve-new.optimized.wat
@@ -88,6 +88,6 @@
   drop
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/resolve-new.untouched.wat b/tests/compiler/resolve-new.untouched.wat
index 7a764dcf44..6441e34b86 100644
--- a/tests/compiler/resolve-new.untouched.wat
+++ b/tests/compiler/resolve-new.untouched.wat
@@ -166,5 +166,6 @@
   call $start:resolve-new
  )
  (func $null (; 8 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/resolve-propertyaccess.optimized.wat b/tests/compiler/resolve-propertyaccess.optimized.wat
index 4eeb7d176d..73c55d01db 100644
--- a/tests/compiler/resolve-propertyaccess.optimized.wat
+++ b/tests/compiler/resolve-propertyaccess.optimized.wat
@@ -495,6 +495,6 @@
   call $start:resolve-propertyaccess
  )
  (func $null (; 11 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/resolve-propertyaccess.untouched.wat b/tests/compiler/resolve-propertyaccess.untouched.wat
index 1aba116117..80ba091bb4 100644
--- a/tests/compiler/resolve-propertyaccess.untouched.wat
+++ b/tests/compiler/resolve-propertyaccess.untouched.wat
@@ -833,5 +833,6 @@
   call $start:resolve-propertyaccess
  )
  (func $null (; 16 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/resolve-ternary.optimized.wat b/tests/compiler/resolve-ternary.optimized.wat
index 910c6c4841..8adc529e1d 100644
--- a/tests/compiler/resolve-ternary.optimized.wat
+++ b/tests/compiler/resolve-ternary.optimized.wat
@@ -3364,6 +3364,6 @@
   end
  )
  (func $null (; 45 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/resolve-ternary.untouched.wat b/tests/compiler/resolve-ternary.untouched.wat
index 76ea65289d..d4ec5ad899 100644
--- a/tests/compiler/resolve-ternary.untouched.wat
+++ b/tests/compiler/resolve-ternary.untouched.wat
@@ -5508,5 +5508,6 @@
   return
  )
  (func $null (; 54 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/resolve-unary.optimized.wat b/tests/compiler/resolve-unary.optimized.wat
index 02da945fdd..6d6bf858eb 100644
--- a/tests/compiler/resolve-unary.optimized.wat
+++ b/tests/compiler/resolve-unary.optimized.wat
@@ -644,6 +644,6 @@
   call $start:resolve-unary
  )
  (func $null (; 12 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/resolve-unary.untouched.wat b/tests/compiler/resolve-unary.untouched.wat
index 88fd3c2c74..41b054e28f 100644
--- a/tests/compiler/resolve-unary.untouched.wat
+++ b/tests/compiler/resolve-unary.untouched.wat
@@ -1271,5 +1271,6 @@
   call $start:resolve-unary
  )
  (func $null (; 32 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/retain-i32.optimized.wat b/tests/compiler/retain-i32.optimized.wat
index 69313b4629..d8a5c83de2 100644
--- a/tests/compiler/retain-i32.optimized.wat
+++ b/tests/compiler/retain-i32.optimized.wat
@@ -70,6 +70,6 @@
   call $start:retain-i32
  )
  (func $null (; 2 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/retain-i32.untouched.wat b/tests/compiler/retain-i32.untouched.wat
index a45d1fc544..51a6b7d71d 100644
--- a/tests/compiler/retain-i32.untouched.wat
+++ b/tests/compiler/retain-i32.untouched.wat
@@ -802,5 +802,6 @@
   call $start:retain-i32
  )
  (func $null (; 5 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/retain-release-sanity.optimized.wat b/tests/compiler/retain-release-sanity.optimized.wat
index c08d372cc3..a3d66f578a 100644
--- a/tests/compiler/retain-release-sanity.optimized.wat
+++ b/tests/compiler/retain-release-sanity.optimized.wat
@@ -2828,6 +2828,6 @@
   end
  )
  (func $null (; 46 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/retain-release-sanity.untouched.wat b/tests/compiler/retain-release-sanity.untouched.wat
index d2bf3b5f1d..b3c01eb149 100644
--- a/tests/compiler/retain-release-sanity.untouched.wat
+++ b/tests/compiler/retain-release-sanity.untouched.wat
@@ -4616,5 +4616,6 @@
   return
  )
  (func $null (; 54 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/retain-release.optimized.wat b/tests/compiler/retain-release.optimized.wat
index 0e495740e7..000564c359 100644
--- a/tests/compiler/retain-release.optimized.wat
+++ b/tests/compiler/retain-release.optimized.wat
@@ -10,7 +10,7 @@
  (data (i32.const 8) "\n\00\00\00\01\00\00\00\01\00\00\00\n\00\00\00e\00r\00r\00o\00r")
  (data (i32.const 40) "\"\00\00\00\01\00\00\00\01\00\00\00\"\00\00\00r\00e\00t\00a\00i\00n\00-\00r\00e\00l\00e\00a\00s\00e\00.\00t\00s")
  (table $0 1 funcref)
- (elem (i32.const 0) $retain-release/receiveRef)
+ (elem (i32.const 0) $null)
  (global $~lib/rt/stub/startOffset (mut i32) (i32.const 0))
  (global $~lib/rt/stub/offset (mut i32) (i32.const 0))
  (global $retain-release/REF (mut i32) (i32.const 0))
@@ -269,4 +269,7 @@
   local.get $0
   global.set $retain-release/TARGET
  )
+ (func $null (; 18 ;) (type $FUNCSIG$v)
+  unreachable
+ )
 )
diff --git a/tests/compiler/retain-release.untouched.wat b/tests/compiler/retain-release.untouched.wat
index 69975fa594..8d5032d761 100644
--- a/tests/compiler/retain-release.untouched.wat
+++ b/tests/compiler/retain-release.untouched.wat
@@ -793,5 +793,6 @@
   call $start:retain-release
  )
  (func $null (; 46 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/rt/flags.untouched.wat b/tests/compiler/rt/flags.untouched.wat
index 54958f4238..d409631911 100644
--- a/tests/compiler/rt/flags.untouched.wat
+++ b/tests/compiler/rt/flags.untouched.wat
@@ -1400,5 +1400,6 @@
   call $start:rt/flags
  )
  (func $null (; 63 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/rt/ids.optimized.wat b/tests/compiler/rt/ids.optimized.wat
index bb456a1172..8a6433fd8c 100644
--- a/tests/compiler/rt/ids.optimized.wat
+++ b/tests/compiler/rt/ids.optimized.wat
@@ -3,6 +3,6 @@
  (memory $0 0)
  (export "memory" (memory $0))
  (func $null (; 0 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/rt/ids.untouched.wat b/tests/compiler/rt/ids.untouched.wat
index 29ee81b836..6cdcf09d9b 100644
--- a/tests/compiler/rt/ids.untouched.wat
+++ b/tests/compiler/rt/ids.untouched.wat
@@ -5,5 +5,6 @@
  (elem (i32.const 0) $null)
  (export "memory" (memory $0))
  (func $null (; 0 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/rt/instanceof.optimized.wat b/tests/compiler/rt/instanceof.optimized.wat
index 7162b0e5bd..8fb000b6ee 100644
--- a/tests/compiler/rt/instanceof.optimized.wat
+++ b/tests/compiler/rt/instanceof.optimized.wat
@@ -521,6 +521,6 @@
   call $start:rt/instanceof
  )
  (func $null (; 9 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/rt/instanceof.untouched.wat b/tests/compiler/rt/instanceof.untouched.wat
index 98b653554d..b7266b88b9 100644
--- a/tests/compiler/rt/instanceof.untouched.wat
+++ b/tests/compiler/rt/instanceof.untouched.wat
@@ -686,5 +686,6 @@
   call $start:rt/instanceof
  )
  (func $null (; 10 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/rt/stub-realloc.optimized.wat b/tests/compiler/rt/stub-realloc.optimized.wat
index 3a55459a93..9fb0a47922 100644
--- a/tests/compiler/rt/stub-realloc.optimized.wat
+++ b/tests/compiler/rt/stub-realloc.optimized.wat
@@ -598,4 +598,7 @@
   global.set $~lib/rt/stub/offset
   call $start:rt/stub-realloc
  )
+ (func $null (; 11 ;) (type $FUNCSIG$v)
+  unreachable
+ )
 )
diff --git a/tests/compiler/rt/stub-realloc.untouched.wat b/tests/compiler/rt/stub-realloc.untouched.wat
index 80c05aa2ab..c87b9878d8 100644
--- a/tests/compiler/rt/stub-realloc.untouched.wat
+++ b/tests/compiler/rt/stub-realloc.untouched.wat
@@ -1735,5 +1735,6 @@
   call $start:rt/stub-realloc
  )
  (func $null (; 12 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/runtime-full.optimized.wat b/tests/compiler/runtime-full.optimized.wat
index 261c212f50..f206f5d4d0 100644
--- a/tests/compiler/runtime-full.optimized.wat
+++ b/tests/compiler/runtime-full.optimized.wat
@@ -1889,6 +1889,6 @@
   unreachable
  )
  (func $null (; 28 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/runtime-full.untouched.wat b/tests/compiler/runtime-full.untouched.wat
index b53d53a26d..5fa0fdcec0 100644
--- a/tests/compiler/runtime-full.untouched.wat
+++ b/tests/compiler/runtime-full.untouched.wat
@@ -3403,5 +3403,6 @@
   unreachable
  )
  (func $null (; 29 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/runtime-half.optimized.wat b/tests/compiler/runtime-half.optimized.wat
index bb456a1172..8a6433fd8c 100644
--- a/tests/compiler/runtime-half.optimized.wat
+++ b/tests/compiler/runtime-half.optimized.wat
@@ -3,6 +3,6 @@
  (memory $0 0)
  (export "memory" (memory $0))
  (func $null (; 0 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/runtime-half.untouched.wat b/tests/compiler/runtime-half.untouched.wat
index 29ee81b836..6cdcf09d9b 100644
--- a/tests/compiler/runtime-half.untouched.wat
+++ b/tests/compiler/runtime-half.untouched.wat
@@ -5,5 +5,6 @@
  (elem (i32.const 0) $null)
  (export "memory" (memory $0))
  (func $null (; 0 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/runtime-none.optimized.wat b/tests/compiler/runtime-none.optimized.wat
index bb456a1172..8a6433fd8c 100644
--- a/tests/compiler/runtime-none.optimized.wat
+++ b/tests/compiler/runtime-none.optimized.wat
@@ -3,6 +3,6 @@
  (memory $0 0)
  (export "memory" (memory $0))
  (func $null (; 0 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/runtime-none.untouched.wat b/tests/compiler/runtime-none.untouched.wat
index 29ee81b836..6cdcf09d9b 100644
--- a/tests/compiler/runtime-none.untouched.wat
+++ b/tests/compiler/runtime-none.untouched.wat
@@ -5,5 +5,6 @@
  (elem (i32.const 0) $null)
  (export "memory" (memory $0))
  (func $null (; 0 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/runtime-stub.optimized.wat b/tests/compiler/runtime-stub.optimized.wat
index f03216c6ac..3f35439ffb 100644
--- a/tests/compiler/runtime-stub.optimized.wat
+++ b/tests/compiler/runtime-stub.optimized.wat
@@ -117,4 +117,7 @@
   i32.const 48
   global.set $~lib/rt/stub/offset
  )
+ (func $null (; 6 ;) (type $FUNCSIG$v)
+  unreachable
+ )
 )
diff --git a/tests/compiler/runtime-stub.untouched.wat b/tests/compiler/runtime-stub.untouched.wat
index e7cc0e83eb..0f4824d960 100644
--- a/tests/compiler/runtime-stub.untouched.wat
+++ b/tests/compiler/runtime-stub.untouched.wat
@@ -147,5 +147,6 @@
   global.set $~lib/rt/stub/offset
  )
  (func $null (; 6 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/scoped.optimized.wat b/tests/compiler/scoped.optimized.wat
index fbd30b0400..46f5ca74d9 100644
--- a/tests/compiler/scoped.optimized.wat
+++ b/tests/compiler/scoped.optimized.wat
@@ -36,6 +36,6 @@
   call $start:scoped
  )
  (func $null (; 2 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/scoped.untouched.wat b/tests/compiler/scoped.untouched.wat
index 61a431f4e8..7d344442ba 100644
--- a/tests/compiler/scoped.untouched.wat
+++ b/tests/compiler/scoped.untouched.wat
@@ -69,5 +69,6 @@
   call $start:scoped
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/simd.untouched.wat b/tests/compiler/simd.untouched.wat
index ed2aec3b8e..618c957bc1 100644
--- a/tests/compiler/simd.untouched.wat
+++ b/tests/compiler/simd.untouched.wat
@@ -2079,5 +2079,6 @@
   call $start:simd
  )
  (func $null (; 11 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/static-this.optimized.wat b/tests/compiler/static-this.optimized.wat
index 1f9aaca932..9db95d31e1 100644
--- a/tests/compiler/static-this.optimized.wat
+++ b/tests/compiler/static-this.optimized.wat
@@ -4,6 +4,6 @@
  (data (i32.const 8) "\1c\00\00\00\01\00\00\00\01\00\00\00\1c\00\00\00s\00t\00a\00t\00i\00c\00-\00t\00h\00i\00s\00.\00t\00s")
  (export "memory" (memory $0))
  (func $null (; 0 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/static-this.untouched.wat b/tests/compiler/static-this.untouched.wat
index f0ff1ce317..9d6159861b 100644
--- a/tests/compiler/static-this.untouched.wat
+++ b/tests/compiler/static-this.untouched.wat
@@ -31,5 +31,6 @@
   call $start:static-this
  )
  (func $null (; 4 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/std/array-access.optimized.wat b/tests/compiler/std/array-access.optimized.wat
index 6c5bd418bf..9b5c76f4bf 100644
--- a/tests/compiler/std/array-access.optimized.wat
+++ b/tests/compiler/std/array-access.optimized.wat
@@ -223,6 +223,6 @@
   call $~lib/string/String#startsWith
  )
  (func $null (; 11 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/std/array-access.untouched.wat b/tests/compiler/std/array-access.untouched.wat
index dead0bbc8e..f4c87ff98f 100644
--- a/tests/compiler/std/array-access.untouched.wat
+++ b/tests/compiler/std/array-access.untouched.wat
@@ -494,5 +494,6 @@
   local.get $3
  )
  (func $null (; 19 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/std/array-literal.optimized.wat b/tests/compiler/std/array-literal.optimized.wat
index 910538e5bd..17c6cd239f 100644
--- a/tests/compiler/std/array-literal.optimized.wat
+++ b/tests/compiler/std/array-literal.optimized.wat
@@ -2402,6 +2402,6 @@
   end
  )
  (func $null (; 40 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/std/array-literal.untouched.wat b/tests/compiler/std/array-literal.untouched.wat
index dc7ac7f4f2..f059a43047 100644
--- a/tests/compiler/std/array-literal.untouched.wat
+++ b/tests/compiler/std/array-literal.untouched.wat
@@ -4097,5 +4097,6 @@
   return
  )
  (func $null (; 50 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/std/array.optimized.wat b/tests/compiler/std/array.optimized.wat
index 2eb02fcd14..e4611bb84d 100644
--- a/tests/compiler/std/array.optimized.wat
+++ b/tests/compiler/std/array.optimized.wat
@@ -10325,8 +10325,7 @@
   (local $2 i32)
   (local $3 i32)
   local.get $0
-  i64.const 0
-  i64.eq
+  i64.eqz
   if
    i32.const 4768
    call $~lib/rt/pure/__retain
@@ -10374,8 +10373,7 @@
   i32.add
   local.set $0
   local.get $2
-  i64.const 0
-  i64.eq
+  i64.eqz
   if
    local.get $0
    i32.const 48
@@ -10535,8 +10533,7 @@
   (local $3 i32)
   (local $4 i32)
   local.get $0
-  i64.const 0
-  i64.eq
+  i64.eqz
   if
    i32.const 4768
    call $~lib/rt/pure/__retain
@@ -10605,8 +10602,7 @@
   i32.add
   local.set $0
   local.get $2
-  i64.const 0
-  i64.eq
+  i64.eqz
   if
    local.get $0
    i32.const 48
@@ -17823,6 +17819,6 @@
   end
  )
  (func $null (; 210 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/std/array.untouched.wat b/tests/compiler/std/array.untouched.wat
index 1db115070e..2352f07628 100644
--- a/tests/compiler/std/array.untouched.wat
+++ b/tests/compiler/std/array.untouched.wat
@@ -25282,5 +25282,6 @@
   return
  )
  (func $null (; 339 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/std/arraybuffer.optimized.wat b/tests/compiler/std/arraybuffer.optimized.wat
index 71dd096b53..a115a0a921 100644
--- a/tests/compiler/std/arraybuffer.optimized.wat
+++ b/tests/compiler/std/arraybuffer.optimized.wat
@@ -2672,6 +2672,6 @@
   end
  )
  (func $null (; 42 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/std/arraybuffer.untouched.wat b/tests/compiler/std/arraybuffer.untouched.wat
index 72f4b98018..03bfca3c30 100644
--- a/tests/compiler/std/arraybuffer.untouched.wat
+++ b/tests/compiler/std/arraybuffer.untouched.wat
@@ -4572,5 +4572,6 @@
   return
  )
  (func $null (; 55 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/std/dataview.optimized.wat b/tests/compiler/std/dataview.optimized.wat
index 786ea8b913..7799dc8258 100644
--- a/tests/compiler/std/dataview.optimized.wat
+++ b/tests/compiler/std/dataview.optimized.wat
@@ -4278,6 +4278,6 @@
   unreachable
  )
  (func $null (; 65 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/std/dataview.untouched.wat b/tests/compiler/std/dataview.untouched.wat
index d73890ab8b..9a683f68d3 100644
--- a/tests/compiler/std/dataview.untouched.wat
+++ b/tests/compiler/std/dataview.untouched.wat
@@ -6415,5 +6415,6 @@
   unreachable
  )
  (func $null (; 70 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/std/date.optimized.wat b/tests/compiler/std/date.optimized.wat
index 18d9ef4aa9..30dfac2019 100644
--- a/tests/compiler/std/date.optimized.wat
+++ b/tests/compiler/std/date.optimized.wat
@@ -97,8 +97,8 @@
   f64.const 0
   call $~lib/bindings/Date/UTC
   i64.trunc_f64_s
-  i64.const 0
-  i64.ne
+  i64.eqz
+  i32.eqz
   if
    i32.const 0
    i32.const 24
@@ -116,8 +116,8 @@
   f64.const 0
   call $~lib/bindings/Date/UTC
   i64.trunc_f64_s
-  i64.const 0
-  i64.ne
+  i64.eqz
+  i32.eqz
   if
    i32.const 0
    i32.const 24
@@ -210,6 +210,6 @@
   call $start:std/date
  )
  (func $null (; 7 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/std/date.untouched.wat b/tests/compiler/std/date.untouched.wat
index 5624c16711..1fb152613f 100644
--- a/tests/compiler/std/date.untouched.wat
+++ b/tests/compiler/std/date.untouched.wat
@@ -342,5 +342,6 @@
   call $start:std/date
  )
  (func $null (; 11 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/std/hash.optimized.wat b/tests/compiler/std/hash.optimized.wat
index 3e763339a6..bdb95aa529 100644
--- a/tests/compiler/std/hash.optimized.wat
+++ b/tests/compiler/std/hash.optimized.wat
@@ -206,6 +206,6 @@
   call $start:std/hash
  )
  (func $null (; 5 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/std/hash.untouched.wat b/tests/compiler/std/hash.untouched.wat
index 97b5312580..85cb616cbd 100644
--- a/tests/compiler/std/hash.untouched.wat
+++ b/tests/compiler/std/hash.untouched.wat
@@ -410,5 +410,6 @@
   call $start:std/hash
  )
  (func $null (; 9 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/std/libm.optimized.wat b/tests/compiler/std/libm.optimized.wat
index 01b2b21aa5..e72a9404be 100644
--- a/tests/compiler/std/libm.optimized.wat
+++ b/tests/compiler/std/libm.optimized.wat
@@ -520,8 +520,7 @@
    local.get $2
    i64.const 1
    i64.shl
-   i64.const 0
-   i64.eq
+   i64.eqz
    if
     f64.const -1
     local.get $0
@@ -563,8 +562,7 @@
     local.get $2
     i64.const 32
     i64.shl
-    i64.const 0
-    i64.eq
+    i64.eqz
     i32.const 0
     local.get $1
     i32.const 1072693248
@@ -2883,8 +2881,7 @@
   local.set $0
   i32.const 1
   local.get $2
-  i64.const 0
-  i64.eq
+  i64.eqz
   local.get $5
   i32.const 2047
   i32.eq
@@ -3066,8 +3063,7 @@
    local.get $3
    i64.const 1
    i64.shl
-   i64.const 0
-   i64.eq
+   i64.eqz
    if
     f64.const -1
     local.get $0
@@ -3109,8 +3105,7 @@
     local.get $3
     i64.const 32
     i64.shl
-    i64.const 0
-    i64.eq
+    i64.eqz
     i32.const 0
     local.get $2
     i32.const 1072693248
@@ -3277,8 +3272,7 @@
    local.get $3
    i64.const 1
    i64.shl
-   i64.const 0
-   i64.eq
+   i64.eqz
    if
     f64.const -1
     local.get $0
@@ -3320,8 +3314,7 @@
     local.get $3
     i64.const 32
     i64.shl
-    i64.const 0
-    i64.eq
+    i64.eqz
     i32.const 0
     local.get $2
     i32.const 1072693248
@@ -9275,6 +9268,6 @@
   f32.trunc
  )
  (func $null (; 120 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/std/libm.untouched.wat b/tests/compiler/std/libm.untouched.wat
index 71254be045..002c3c7094 100644
--- a/tests/compiler/std/libm.untouched.wat
+++ b/tests/compiler/std/libm.untouched.wat
@@ -12541,5 +12541,6 @@
   f32.trunc
  )
  (func $null (; 122 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/std/map.optimized.wat b/tests/compiler/std/map.optimized.wat
index 4f476155ae..1b3fec703c 100644
--- a/tests/compiler/std/map.optimized.wat
+++ b/tests/compiler/std/map.optimized.wat
@@ -8737,6 +8737,6 @@
   call $~lib/rt/pure/__visit
  )
  (func $null (; 107 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/std/map.untouched.wat b/tests/compiler/std/map.untouched.wat
index 00239b3a7d..f79e09675c 100644
--- a/tests/compiler/std/map.untouched.wat
+++ b/tests/compiler/std/map.untouched.wat
@@ -12720,5 +12720,6 @@
   unreachable
  )
  (func $null (; 151 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/std/math.optimized.wat b/tests/compiler/std/math.optimized.wat
index bb1b370b5d..9655cd8b68 100644
--- a/tests/compiler/std/math.optimized.wat
+++ b/tests/compiler/std/math.optimized.wat
@@ -1068,8 +1068,7 @@
    local.get $2
    i64.const 1
    i64.shl
-   i64.const 0
-   i64.eq
+   i64.eqz
    if
     f64.const -1
     local.get $0
@@ -1111,8 +1110,7 @@
     local.get $2
     i64.const 32
     i64.shl
-    i64.const 0
-    i64.eq
+    i64.eqz
     i32.const 0
     local.get $1
     i32.const 1072693248
@@ -5321,8 +5319,7 @@
   local.set $0
   i32.const 1
   local.get $2
-  i64.const 0
-  i64.eq
+  i64.eqz
   local.get $5
   i32.const 2047
   i32.eq
@@ -5613,8 +5610,7 @@
    local.get $3
    i64.const 1
    i64.shl
-   i64.const 0
-   i64.eq
+   i64.eqz
    if
     f64.const -1
     local.get $0
@@ -5656,8 +5652,7 @@
     local.get $3
     i64.const 32
     i64.shl
-    i64.const 0
-    i64.eq
+    i64.eqz
     i32.const 0
     local.get $2
     i32.const 1072693248
@@ -6020,8 +6015,7 @@
    local.get $3
    i64.const 1
    i64.shl
-   i64.const 0
-   i64.eq
+   i64.eqz
    if
     f64.const -1
     local.get $0
@@ -6063,8 +6057,7 @@
     local.get $3
     i64.const 32
     i64.shl
-    i64.const 0
-    i64.eq
+    i64.eqz
     i32.const 0
     local.get $2
     i32.const 1072693248
@@ -6446,8 +6439,7 @@
   i64.const 1
   i64.shl
   local.tee $6
-  i64.const 0
-  i64.eq
+  i64.eqz
   if (result i32)
    i32.const 1
   else
@@ -6487,8 +6479,7 @@
     return
    end
    local.get $4
-   i64.const 0
-   i64.eq
+   i64.eqz
    if (result i64)
     local.get $2
     i64.const 0
@@ -6512,8 +6503,7 @@
    end
    local.set $2
    local.get $5
-   i64.const 0
-   i64.eq
+   i64.eqz
    if (result i64)
     local.get $3
     i64.const 0
@@ -8846,8 +8836,7 @@
   local.get $4
   i64.const 1
   i64.shl
-  i64.const 0
-  i64.eq
+  i64.eqz
   select
   select
   if
@@ -8862,15 +8851,13 @@
   local.get $2
   i64.const 1
   i64.shl
-  i64.const 0
-  i64.eq
+  i64.eqz
   if
    local.get $0
    return
   end
   local.get $3
-  i64.const 0
-  i64.eq
+  i64.eqz
   if (result i64)
    local.get $2
    i64.const 0
@@ -8894,8 +8881,7 @@
   end
   local.set $2
   local.get $6
-  i64.const 0
-  i64.eq
+  i64.eqz
   if (result i64)
    local.get $4
    i64.const 0
@@ -8980,8 +8966,7 @@
     local.set $5
    end
    local.get $2
-   i64.const 0
-   i64.eq
+   i64.eqz
    if
     i64.const -60
     local.set $3
@@ -45417,8 +45402,8 @@
   i64.const 0
   i32.const 1
   call $~lib/math/ipow64
-  i64.const 0
-  i64.ne
+  i64.eqz
+  i32.eqz
   if
    i32.const 0
    i32.const 24
@@ -45430,8 +45415,8 @@
   i64.const 0
   i32.const 2
   call $~lib/math/ipow64
-  i64.const 0
-  i64.ne
+  i64.eqz
+  i32.eqz
   if
    i32.const 0
    i32.const 24
@@ -45443,8 +45428,8 @@
   i64.const 0
   i32.const 3
   call $~lib/math/ipow64
-  i64.const 0
-  i64.ne
+  i64.eqz
+  i32.eqz
   if
    i32.const 0
    i32.const 24
@@ -46196,6 +46181,6 @@
   call $start:std/math
  )
  (func $null (; 173 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/std/math.untouched.wat b/tests/compiler/std/math.untouched.wat
index 00c5ddb364..fa23daaed2 100644
--- a/tests/compiler/std/math.untouched.wat
+++ b/tests/compiler/std/math.untouched.wat
@@ -54554,5 +54554,6 @@
   call $start:std/math
  )
  (func $null (; 175 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/std/mod.optimized.wat b/tests/compiler/std/mod.optimized.wat
index 2c2e9abf58..f72a29caaf 100644
--- a/tests/compiler/std/mod.optimized.wat
+++ b/tests/compiler/std/mod.optimized.wat
@@ -46,8 +46,7 @@
   i64.const 1
   i64.shl
   local.tee $6
-  i64.const 0
-  i64.eq
+  i64.eqz
   if (result i32)
    i32.const 1
   else
@@ -87,8 +86,7 @@
     return
    end
    local.get $4
-   i64.const 0
-   i64.eq
+   i64.eqz
    if (result i64)
     local.get $2
     i64.const 0
@@ -112,8 +110,7 @@
    end
    local.set $2
    local.get $5
-   i64.const 0
-   i64.eq
+   i64.eqz
    if (result i64)
     local.get $3
     i64.const 0
@@ -2250,6 +2247,6 @@
   call $start:std/mod
  )
  (func $null (; 10 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/std/mod.untouched.wat b/tests/compiler/std/mod.untouched.wat
index 4a675a1f87..2ba3031b08 100644
--- a/tests/compiler/std/mod.untouched.wat
+++ b/tests/compiler/std/mod.untouched.wat
@@ -2365,5 +2365,6 @@
   call $start:std/mod
  )
  (func $null (; 10 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/std/new.optimized.wat b/tests/compiler/std/new.optimized.wat
index d537cbb35b..b5c7fbc1a5 100644
--- a/tests/compiler/std/new.optimized.wat
+++ b/tests/compiler/std/new.optimized.wat
@@ -106,6 +106,6 @@
   global.set $std/new/aClass
  )
  (func $null (; 4 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/std/new.untouched.wat b/tests/compiler/std/new.untouched.wat
index e5cc939cfe..31d20dc9ec 100644
--- a/tests/compiler/std/new.untouched.wat
+++ b/tests/compiler/std/new.untouched.wat
@@ -171,5 +171,6 @@
   call $start:std/new
  )
  (func $null (; 6 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/std/object-literal.optimized.wat b/tests/compiler/std/object-literal.optimized.wat
index c2c9990265..400fd3b0a0 100644
--- a/tests/compiler/std/object-literal.optimized.wat
+++ b/tests/compiler/std/object-literal.optimized.wat
@@ -300,6 +300,6 @@
   call $start:std/object-literal
  )
  (func $null (; 9 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/std/object-literal.untouched.wat b/tests/compiler/std/object-literal.untouched.wat
index 13ae5e568a..af4e1062e2 100644
--- a/tests/compiler/std/object-literal.untouched.wat
+++ b/tests/compiler/std/object-literal.untouched.wat
@@ -457,5 +457,6 @@
   call $start:std/object-literal
  )
  (func $null (; 13 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/std/object.optimized.wat b/tests/compiler/std/object.optimized.wat
index 85395d2262..df19f9a6f6 100644
--- a/tests/compiler/std/object.optimized.wat
+++ b/tests/compiler/std/object.optimized.wat
@@ -672,6 +672,6 @@
   call $start:std/object
  )
  (func $null (; 11 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/std/object.untouched.wat b/tests/compiler/std/object.untouched.wat
index dffbfdbf70..aa62f4a4ee 100644
--- a/tests/compiler/std/object.untouched.wat
+++ b/tests/compiler/std/object.untouched.wat
@@ -889,5 +889,6 @@
   call $start:std/object
  )
  (func $null (; 15 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/std/operator-overloading.optimized.wat b/tests/compiler/std/operator-overloading.optimized.wat
index 6c7927dd2b..f318da0f52 100644
--- a/tests/compiler/std/operator-overloading.optimized.wat
+++ b/tests/compiler/std/operator-overloading.optimized.wat
@@ -2385,6 +2385,6 @@
   call $start:std/operator-overloading
  )
  (func $null (; 13 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/std/operator-overloading.untouched.wat b/tests/compiler/std/operator-overloading.untouched.wat
index 4aaba657c5..554bd87066 100644
--- a/tests/compiler/std/operator-overloading.untouched.wat
+++ b/tests/compiler/std/operator-overloading.untouched.wat
@@ -3293,5 +3293,6 @@
   call $start:std/operator-overloading
  )
  (func $null (; 38 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/std/pointer.optimized.wat b/tests/compiler/std/pointer.optimized.wat
index 2dbea92c9e..aa90691878 100644
--- a/tests/compiler/std/pointer.optimized.wat
+++ b/tests/compiler/std/pointer.optimized.wat
@@ -611,6 +611,6 @@
   call $start:std/pointer
  )
  (func $null (; 5 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/std/pointer.untouched.wat b/tests/compiler/std/pointer.untouched.wat
index 659b2264fb..773bf87a23 100644
--- a/tests/compiler/std/pointer.untouched.wat
+++ b/tests/compiler/std/pointer.untouched.wat
@@ -2211,5 +2211,6 @@
   call $start:std/pointer
  )
  (func $null (; 8 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/std/polyfills.optimized.wat b/tests/compiler/std/polyfills.optimized.wat
index cf67499b8a..e1f7625727 100644
--- a/tests/compiler/std/polyfills.optimized.wat
+++ b/tests/compiler/std/polyfills.optimized.wat
@@ -3,7 +3,7 @@
  (memory $0 1)
  (data (i32.const 8) " \00\00\00\01\00\00\00\01\00\00\00 \00\00\00s\00t\00d\00/\00p\00o\00l\00y\00f\00i\00l\00l\00s\00.\00t\00s")
  (export "memory" (memory $0))
- (func $start (; 0 ;) (type $FUNCSIG$v)
-  nop
+ (func $null (; 0 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/std/polyfills.untouched.wat b/tests/compiler/std/polyfills.untouched.wat
index 8d4e727be6..f490e6adef 100644
--- a/tests/compiler/std/polyfills.untouched.wat
+++ b/tests/compiler/std/polyfills.untouched.wat
@@ -494,5 +494,6 @@
   call $start:std/polyfills
  )
  (func $null (; 19 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/std/set.optimized.wat b/tests/compiler/std/set.optimized.wat
index 1d49e53971..c92e66770e 100644
--- a/tests/compiler/std/set.optimized.wat
+++ b/tests/compiler/std/set.optimized.wat
@@ -7632,6 +7632,6 @@
   call $~lib/rt/pure/__visit
  )
  (func $null (; 99 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/std/set.untouched.wat b/tests/compiler/std/set.untouched.wat
index 57a6df6624..04714855a7 100644
--- a/tests/compiler/std/set.untouched.wat
+++ b/tests/compiler/std/set.untouched.wat
@@ -11432,5 +11432,6 @@
   unreachable
  )
  (func $null (; 141 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/std/simd.optimized.wat b/tests/compiler/std/simd.optimized.wat
index bb456a1172..8a6433fd8c 100644
--- a/tests/compiler/std/simd.optimized.wat
+++ b/tests/compiler/std/simd.optimized.wat
@@ -3,6 +3,6 @@
  (memory $0 0)
  (export "memory" (memory $0))
  (func $null (; 0 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/std/simd.untouched.wat b/tests/compiler/std/simd.untouched.wat
index 9f14327565..315fb4ca0c 100644
--- a/tests/compiler/std/simd.untouched.wat
+++ b/tests/compiler/std/simd.untouched.wat
@@ -6,5 +6,6 @@
  (global $~lib/ASC_FEATURE_SIMD i32 (i32.const 0))
  (export "memory" (memory $0))
  (func $null (; 0 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/std/static-array.optimized.wat b/tests/compiler/std/static-array.optimized.wat
index 6f55ffc8d6..78b52f671d 100644
--- a/tests/compiler/std/static-array.optimized.wat
+++ b/tests/compiler/std/static-array.optimized.wat
@@ -1029,6 +1029,6 @@
   call $start:std/static-array
  )
  (func $null (; 17 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/std/static-array.untouched.wat b/tests/compiler/std/static-array.untouched.wat
index 388042c8e9..05d6e1b607 100644
--- a/tests/compiler/std/static-array.untouched.wat
+++ b/tests/compiler/std/static-array.untouched.wat
@@ -2369,5 +2369,6 @@
   call $start:std/static-array
  )
  (func $null (; 31 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/std/string-encoding.optimized.wat b/tests/compiler/std/string-encoding.optimized.wat
index 69fb402a54..923e7da5f4 100644
--- a/tests/compiler/std/string-encoding.optimized.wat
+++ b/tests/compiler/std/string-encoding.optimized.wat
@@ -3925,6 +3925,6 @@
   unreachable
  )
  (func $null (; 58 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/std/string-encoding.untouched.wat b/tests/compiler/std/string-encoding.untouched.wat
index e34a9f852e..27cd41d557 100644
--- a/tests/compiler/std/string-encoding.untouched.wat
+++ b/tests/compiler/std/string-encoding.untouched.wat
@@ -5664,5 +5664,6 @@
   unreachable
  )
  (func $null (; 60 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/std/string.optimized.wat b/tests/compiler/std/string.optimized.wat
index 46cbc320d2..8b03d59c6b 100644
--- a/tests/compiler/std/string.optimized.wat
+++ b/tests/compiler/std/string.optimized.wat
@@ -4366,8 +4366,7 @@
     i32.const -342
     i32.lt_s
     local.get $2
-    i64.const 0
-    i64.eq
+    i64.eqz
     select
     if
      br $~lib/util/string/scientific|inlined.0
@@ -6503,8 +6502,7 @@
   (local $2 i32)
   (local $3 i32)
   local.get $0
-  i64.const 0
-  i64.eq
+  i64.eqz
   if
    i32.const 1192
    call $~lib/rt/pure/__retain
@@ -6549,8 +6547,7 @@
   (local $3 i32)
   (local $4 i32)
   local.get $0
-  i64.const 0
-  i64.eq
+  i64.eqz
   if
    i32.const 1192
    call $~lib/rt/pure/__retain
@@ -14758,6 +14755,6 @@
   end
  )
  (func $null (; 95 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/std/string.untouched.wat b/tests/compiler/std/string.untouched.wat
index ac453c9481..d8f047ceeb 100644
--- a/tests/compiler/std/string.untouched.wat
+++ b/tests/compiler/std/string.untouched.wat
@@ -18533,5 +18533,6 @@
   return
  )
  (func $null (; 109 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/std/symbol.optimized.wat b/tests/compiler/std/symbol.optimized.wat
index d72b18e094..80bc9b5595 100644
--- a/tests/compiler/std/symbol.optimized.wat
+++ b/tests/compiler/std/symbol.optimized.wat
@@ -1716,6 +1716,6 @@
   call $start:std/symbol
  )
  (func $null (; 31 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/std/symbol.untouched.wat b/tests/compiler/std/symbol.untouched.wat
index 7774c4e106..6df51d3e1b 100644
--- a/tests/compiler/std/symbol.untouched.wat
+++ b/tests/compiler/std/symbol.untouched.wat
@@ -3621,5 +3621,6 @@
   call $start:std/symbol
  )
  (func $null (; 36 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/std/trace.optimized.wat b/tests/compiler/std/trace.optimized.wat
index adeabfc6a6..2140edacb2 100644
--- a/tests/compiler/std/trace.optimized.wat
+++ b/tests/compiler/std/trace.optimized.wat
@@ -91,6 +91,6 @@
   call $start:std/trace
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/std/trace.untouched.wat b/tests/compiler/std/trace.untouched.wat
index db4a48f8f0..a2eab63a6d 100644
--- a/tests/compiler/std/trace.untouched.wat
+++ b/tests/compiler/std/trace.untouched.wat
@@ -93,5 +93,6 @@
   call $start:std/trace
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/std/typedarray.optimized.wat b/tests/compiler/std/typedarray.optimized.wat
index b4277d4598..1ca3f3aa4e 100644
--- a/tests/compiler/std/typedarray.optimized.wat
+++ b/tests/compiler/std/typedarray.optimized.wat
@@ -10598,8 +10598,7 @@
   local.get $2
   call $~lib/rt/pure/__release
   local.get $0
-  i64.const 0
-  i64.eq
+  i64.eqz
  )
  (func $std/typedarray/testArraySome<~lib/typedarray/Int64Array,i64> (; 209 ;) (type $FUNCSIG$v)
   (local $0 i32)
@@ -12619,8 +12618,7 @@
   local.get $0
   i64.const 2
   i64.rem_s
-  i64.const 0
-  i64.eq
+  i64.eqz
   local.get $2
   call $~lib/rt/pure/__release
  )
@@ -12730,8 +12728,7 @@
   local.get $0
   i64.const 2
   i64.rem_u
-  i64.const 0
-  i64.eq
+  i64.eqz
   local.get $2
   call $~lib/rt/pure/__release
  )
@@ -13088,8 +13085,7 @@
     return
    end
    local.get $2
-   i64.const 0
-   i64.eq
+   i64.eqz
    if (result i64)
     local.get $1
     i64.const 0
@@ -25033,8 +25029,7 @@
   (local $3 i32)
   (local $4 i32)
   local.get $0
-  i64.const 0
-  i64.eq
+  i64.eqz
   if
    i32.const 1720
    call $~lib/rt/pure/__retain
@@ -25103,8 +25098,7 @@
   i32.add
   local.set $0
   local.get $2
-  i64.const 0
-  i64.eq
+  i64.eqz
   if
    local.get $0
    i32.const 48
@@ -25362,8 +25356,7 @@
   (local $2 i32)
   (local $3 i32)
   local.get $0
-  i64.const 0
-  i64.eq
+  i64.eqz
   if
    i32.const 1720
    call $~lib/rt/pure/__retain
@@ -25411,8 +25404,7 @@
   i32.add
   local.set $0
   local.get $2
-  i64.const 0
-  i64.eq
+  i64.eqz
   if
    local.get $0
    i32.const 48
@@ -31457,6 +31449,6 @@
   end
  )
  (func $null (; 440 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/std/typedarray.untouched.wat b/tests/compiler/std/typedarray.untouched.wat
index 2adda9e55a..6e58552db8 100644
--- a/tests/compiler/std/typedarray.untouched.wat
+++ b/tests/compiler/std/typedarray.untouched.wat
@@ -42740,5 +42740,6 @@
   return
  )
  (func $null (; 599 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/switch.optimized.wat b/tests/compiler/switch.optimized.wat
index 36e820fc0e..ab36d9d934 100644
--- a/tests/compiler/switch.optimized.wat
+++ b/tests/compiler/switch.optimized.wat
@@ -398,6 +398,6 @@
   call $start:switch
  )
  (func $null (; 7 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/switch.untouched.wat b/tests/compiler/switch.untouched.wat
index f3e60871c8..2d1c91c69c 100644
--- a/tests/compiler/switch.untouched.wat
+++ b/tests/compiler/switch.untouched.wat
@@ -553,5 +553,6 @@
   call $start:switch
  )
  (func $null (; 10 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/ternary.optimized.wat b/tests/compiler/ternary.optimized.wat
index 56846df9d8..45ca377e02 100644
--- a/tests/compiler/ternary.optimized.wat
+++ b/tests/compiler/ternary.optimized.wat
@@ -13,6 +13,6 @@
   global.set $ternary/a
  )
  (func $null (; 1 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/ternary.untouched.wat b/tests/compiler/ternary.untouched.wat
index e281029495..1d575a373c 100644
--- a/tests/compiler/ternary.untouched.wat
+++ b/tests/compiler/ternary.untouched.wat
@@ -24,5 +24,6 @@
   call $start:ternary
  )
  (func $null (; 2 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/typealias.optimized.wat b/tests/compiler/typealias.optimized.wat
index 4a7b9bd96f..7e8774f913 100644
--- a/tests/compiler/typealias.optimized.wat
+++ b/tests/compiler/typealias.optimized.wat
@@ -8,6 +8,6 @@
   local.get $0
  )
  (func $null (; 1 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/typealias.untouched.wat b/tests/compiler/typealias.untouched.wat
index 8cd06aa993..95942fe123 100644
--- a/tests/compiler/typealias.untouched.wat
+++ b/tests/compiler/typealias.untouched.wat
@@ -10,5 +10,6 @@
   local.get $0
  )
  (func $null (; 1 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/typeof.optimized.wat b/tests/compiler/typeof.optimized.wat
index c909cc17a2..03f85c497d 100644
--- a/tests/compiler/typeof.optimized.wat
+++ b/tests/compiler/typeof.optimized.wat
@@ -508,4 +508,7 @@
   end
   call $start:typeof
  )
+ (func $null (; 9 ;) (type $FUNCSIG$v)
+  unreachable
+ )
 )
diff --git a/tests/compiler/typeof.untouched.wat b/tests/compiler/typeof.untouched.wat
index 2102990eef..4cce075fc1 100644
--- a/tests/compiler/typeof.untouched.wat
+++ b/tests/compiler/typeof.untouched.wat
@@ -664,5 +664,6 @@
   call $start:typeof
  )
  (func $null (; 12 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/unary.optimized.wat b/tests/compiler/unary.optimized.wat
index 311ea53583..2e4e9b1800 100644
--- a/tests/compiler/unary.optimized.wat
+++ b/tests/compiler/unary.optimized.wat
@@ -94,8 +94,7 @@
   i64.const 2
   global.set $unary/I
   global.get $unary/I
-  i64.const 0
-  i64.eq
+  i64.eqz
   i64.extend_i32_u
   global.set $unary/I
   global.get $unary/I
@@ -242,6 +241,6 @@
   call $start:unary
  )
  (func $null (; 2 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/unary.untouched.wat b/tests/compiler/unary.untouched.wat
index 516a6b0322..883d0a413f 100644
--- a/tests/compiler/unary.untouched.wat
+++ b/tests/compiler/unary.untouched.wat
@@ -384,5 +384,6 @@
   call $start:unary
  )
  (func $null (; 2 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/void.optimized.wat b/tests/compiler/void.optimized.wat
index e2acb0a3b8..8a6433fd8c 100644
--- a/tests/compiler/void.optimized.wat
+++ b/tests/compiler/void.optimized.wat
@@ -2,7 +2,7 @@
  (type $FUNCSIG$v (func))
  (memory $0 0)
  (export "memory" (memory $0))
- (func $start (; 0 ;) (type $FUNCSIG$v)
-  nop
+ (func $null (; 0 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/void.untouched.wat b/tests/compiler/void.untouched.wat
index a46ab488c7..e2fb924e7f 100644
--- a/tests/compiler/void.untouched.wat
+++ b/tests/compiler/void.untouched.wat
@@ -25,5 +25,6 @@
   call $start:void
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/wasi.optimized.wat b/tests/compiler/wasi.optimized.wat
index f75895f9ab..fd3685a01f 100644
--- a/tests/compiler/wasi.optimized.wat
+++ b/tests/compiler/wasi.optimized.wat
@@ -9,6 +9,6 @@
   global.set $wasi/sig
  )
  (func $null (; 1 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/wasi.untouched.wat b/tests/compiler/wasi.untouched.wat
index ee4e532c29..d7875a78d6 100644
--- a/tests/compiler/wasi.untouched.wat
+++ b/tests/compiler/wasi.untouched.wat
@@ -18,5 +18,6 @@
   call $start:wasi
  )
  (func $null (; 2 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/while.optimized.wat b/tests/compiler/while.optimized.wat
index 2ee89bf010..42f3d0f510 100644
--- a/tests/compiler/while.optimized.wat
+++ b/tests/compiler/while.optimized.wat
@@ -175,6 +175,6 @@
   call $start:while
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
-  nop
+  unreachable
  )
 )
diff --git a/tests/compiler/while.untouched.wat b/tests/compiler/while.untouched.wat
index facc150e49..ca881c7e22 100644
--- a/tests/compiler/while.untouched.wat
+++ b/tests/compiler/while.untouched.wat
@@ -209,5 +209,6 @@
   call $start:while
  )
  (func $null (; 3 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/wildcard-export.optimized.wat b/tests/compiler/wildcard-export.optimized.wat
index 306f12dff1..26ece05287 100644
--- a/tests/compiler/wildcard-export.optimized.wat
+++ b/tests/compiler/wildcard-export.optimized.wat
@@ -8,7 +8,7 @@
  (export "renamed_a" (global $export/a))
  (export "renamed_b" (global $export/b))
  (export "renamed_renamed_b" (global $export/b))
- (func $start (; 0 ;) (type $FUNCSIG$v)
-  nop
+ (func $null (; 0 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/compiler/wildcard-export.untouched.wat b/tests/compiler/wildcard-export.untouched.wat
index b86295da07..088e7ae84a 100644
--- a/tests/compiler/wildcard-export.untouched.wat
+++ b/tests/compiler/wildcard-export.untouched.wat
@@ -43,5 +43,6 @@
   call $start:wildcard-export
  )
  (func $null (; 6 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )
diff --git a/tests/features.json b/tests/features.json
index 312a4138c4..fc4884d8c5 100644
--- a/tests/features.json
+++ b/tests/features.json
@@ -29,5 +29,13 @@
     "v8_flags": [
       "--experimental-wasm-bigint"
     ]
+  },
+  "exception-handling": {
+    "asc_flags": [
+      "--enable exception-handling"
+    ],
+    "v8_flags": [
+      "--experimental-wasm-eh"
+    ]
   }
 }
diff --git a/tests/runtime/untouched.wat b/tests/runtime/untouched.wat
index 628180b86e..732e633218 100644
--- a/tests/runtime/untouched.wat
+++ b/tests/runtime/untouched.wat
@@ -70,7 +70,7 @@
    local.get $3
    i32.const 1073741808
    i32.lt_u
-  else   
+  else
    i32.const 0
   end
   i32.eqz
@@ -92,7 +92,7 @@
    i32.const 4
    i32.shr_u
    local.set $5
-  else   
+  else
    i32.const 31
    local.get $3
    i32.clz
@@ -122,7 +122,7 @@
    local.get $5
    i32.const 16
    i32.lt_u
-  else   
+  else
    i32.const 0
   end
   i32.eqz
@@ -437,7 +437,7 @@
    local.get $8
    i32.const 1073741808
    i32.lt_u
-  else   
+  else
    i32.const 0
   end
   i32.eqz
@@ -480,7 +480,7 @@
    i32.const 4
    i32.shr_u
    local.set $10
-  else   
+  else
    i32.const 31
    local.get $8
    i32.clz
@@ -510,7 +510,7 @@
    local.get $10
    i32.const 16
    i32.lt_u
-  else   
+  else
    i32.const 0
   end
   i32.eqz
@@ -629,7 +629,7 @@
    i32.const 15
    i32.and
    i32.eqz
-  else   
+  else
    i32.const 0
   end
   if (result i32)
@@ -637,7 +637,7 @@
    i32.const 15
    i32.and
    i32.eqz
-  else   
+  else
    i32.const 0
   end
   i32.eqz
@@ -687,10 +687,10 @@
     local.get $4
     i32.load
     local.set $5
-   else    
+   else
     nop
    end
-  else   
+  else
    local.get $1
    local.get $0
    i32.const 1572
@@ -808,7 +808,7 @@
    memory.grow
    i32.const 0
    i32.lt_s
-  else   
+  else
    i32.const 0
   end
   if
@@ -966,7 +966,7 @@
    i32.const 4
    i32.shr_u
    local.set $3
-  else   
+  else
    local.get $1
    i32.const 536870904
    i32.lt_u
@@ -981,7 +981,7 @@
     i32.add
     i32.const 1
     i32.sub
-   else    
+   else
     local.get $1
    end
    local.set $4
@@ -1014,7 +1014,7 @@
    local.get $3
    i32.const 16
    i32.lt_u
-  else   
+  else
    i32.const 0
   end
   i32.eqz
@@ -1066,7 +1066,7 @@
    if
     i32.const 0
     local.set $7
-   else    
+   else
     local.get $5
     i32.ctz
     local.set $2
@@ -1114,7 +1114,7 @@
     end
     local.set $7
    end
-  else   
+  else
    block $~lib/rt/tlsf/GETHEAD|inlined.3 (result i32)
     local.get $0
     local.set $9
@@ -1246,7 +1246,7 @@
    local.get $0
    local.get $5
    call $~lib/rt/tlsf/insertBlock
-  else   
+  else
    local.get $1
    local.get $3
    i32.const 1
@@ -1498,7 +1498,7 @@
      local.get $1
      i32.const 3
      i32.and
-    else     
+    else
      i32.const 0
     end
     if
@@ -2703,7 +2703,7 @@
    i32.le_u
    if (result i32)
     i32.const 1
-   else    
+   else
     local.get $5
     local.get $3
     i32.add
@@ -2823,7 +2823,7 @@
       end
      end
     end
-   else    
+   else
     local.get $4
     i32.const 7
     i32.and
@@ -2924,7 +2924,7 @@
    i32.const 15
    i32.and
    i32.eqz
-  else   
+  else
    i32.const 0
   end
   i32.eqz
@@ -3053,7 +3053,7 @@
     global.get $~lib/rt/tlsf/ROOT
     local.get $0
     call $~lib/rt/tlsf/freeBlock
-   else    
+   else
     local.get $0
     i32.const -2147483648
     i32.const 0
@@ -3062,7 +3062,7 @@
     i32.or
     i32.store offset=4
    end
-  else   
+  else
    local.get $2
    i32.const 0
    i32.gt_u
@@ -3099,7 +3099,7 @@
      local.get $0
      call $~lib/rt/pure/appendRoot
     end
-   else    
+   else
     local.get $0
     local.get $1
     i32.const 268435455
@@ -3188,7 +3188,7 @@
    if
     local.get $0
     call $~lib/rt/pure/scanBlack
-   else    
+   else
     local.get $0
     local.get $1
     i32.const 1879048192
@@ -3221,7 +3221,7 @@
    i32.const -2147483648
    i32.and
    i32.eqz
-  else   
+  else
    i32.const 0
   end
   if
@@ -3285,7 +3285,7 @@
      i32.and
      i32.const 0
      i32.gt_u
-    else     
+    else
      i32.const 0
     end
     if
@@ -3298,7 +3298,7 @@
      i32.const 4
      i32.add
      local.set $1
-    else     
+    else
      local.get $5
      i32.const 1879048192
      i32.and
@@ -3309,14 +3309,14 @@
       i32.const 268435455
       i32.and
       i32.eqz
-     else      
+     else
       i32.const 0
      end
      if
       global.get $~lib/rt/tlsf/ROOT
       local.get $4
       call $~lib/rt/tlsf/freeBlock
-     else      
+     else
       local.get $4
       local.get $5
       i32.const -2147483648
@@ -3604,5 +3604,6 @@
   end
  )
  (func $null (; 29 ;) (type $FUNCSIG$v)
+  unreachable
  )
 )