make the NoInstructionsRemaining error variant uncatchable

boa-dev · Nov 6, 2022 · a8a8f83 · a8a8f83
1 parent 06c4807
commit a8a8f83
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Showing 2 changed files with 10 additions and 10 deletions.
diff --git a/boa_engine/src/error.rs b/boa_engine/src/error.rs
@@ -632,9 +632,9 @@ impl JsNativeError {
             JsNativeErrorKind::Uri => (constructors.uri_error().prototype(), ErrorKind::Uri),
             #[cfg(feature = "fuzz")]
             JsNativeErrorKind::NoInstructionsRemain => {
-                // we can propagate out from try/catch since the catch block will also perform some
-                // operation
-                (constructors.error().prototype(), ErrorKind::Error)
+                unreachable!(
+                    "The NoInstructionsRemain native error cannot be converted to an opaque type."
+                )
             }
         };
 

diff --git a/boa_engine/src/vm/mod.rs b/boa_engine/src/vm/mod.rs
@@ -112,13 +112,6 @@ pub(crate) enum ReturnType {
 
 impl Context {
     fn execute_instruction(&mut self) -> JsResult<ShouldExit> {
-        #[cfg(feature = "fuzz")]
-        if self.insns_remaining == 0 {
-            return Err(JsError::from_native(JsNativeError::no_instructions_remain()));
-        } else {
-            self.insns_remaining -= 1;
-        }
-
         let opcode: Opcode = {
             let _timer = Profiler::global().start_event("Opcode retrieval", "vm");
             let opcode = self.vm.frame().code.code[self.vm.frame().pc]
@@ -186,6 +179,13 @@ impl Context {
             });
 
         while self.vm.frame().pc < self.vm.frame().code.code.len() {
+            #[cfg(feature = "fuzz")]
+            if self.insns_remaining == 0 {
+                return Err(JsError::from_native(JsNativeError::no_instructions_remain()));
+            } else {
+                self.insns_remaining -= 1;
+            }
+
             let result = if self.vm.trace {
                 let mut pc = self.vm.frame().pc;
                 let opcode: Opcode = self