fix: issue with for .. in .. loop returning undefined value instead…

… of false. Closes #87
VirusTotal · Feb 29, 2024 · ce6f7e8 · ce6f7e8
1 parent 889a7cd
commit ce6f7e8
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Showing 2 changed files with 27 additions and 9 deletions.
diff --git a/lib/src/compiler/emit.rs b/lib/src/compiler/emit.rs
@@ -1617,17 +1617,29 @@ fn emit_for_in_range(
         |ctx, instr, n, loop_end| {
             // Set n = upper_bound - lower_bound + 1;
             set_var(ctx, instr, n, |ctx, instr| {
-                emit_expr(ctx, instr, &mut range.upper_bound);
-                emit_expr(ctx, instr, &mut range.lower_bound);
+                // Catch undefined values in upper_bound and lower_bound
+                // expressions. In such cases n = 0.
+                catch_undef(
+                    ctx,
+                    I64,
+                    instr,
+                    |ctx, instr| {
+                        emit_expr(ctx, instr, &mut range.upper_bound);
+                        emit_expr(ctx, instr, &mut range.lower_bound);
 
-                // Store lower_bound in temp variable, without removing
-                // it from the stack.
-                instr.local_tee(ctx.wasm_symbols.i64_tmp);
+                        // Store lower_bound in temp variable, without removing
+                        // it from the stack.
+                        instr.local_tee(ctx.wasm_symbols.i64_tmp);
 
-                // Compute upper_bound - lower_bound + 1.
-                instr.binop(BinaryOp::I64Sub);
-                instr.i64_const(1);
-                instr.binop(BinaryOp::I64Add);
+                        // Compute upper_bound - lower_bound + 1.
+                        instr.binop(BinaryOp::I64Sub);
+                        instr.i64_const(1);
+                        instr.binop(BinaryOp::I64Add);
+                    },
+                    |instr| {
+                        instr.i64_const(0);
+                    },
+                )
             });
 
             // If n <= 0, exit from the loop.

diff --git a/lib/src/tests/mod.rs b/lib/src/tests/mod.rs
@@ -470,6 +470,12 @@ fn for_in() {
     condition_true!(r#"for 2 s in ("foo", "bar", "baz") : (s contains "ba")"#);
     condition_true!(r#"for all x in (1.0, 2.0, 3.0) : (x >= 1.0)"#);
     condition_true!(r#"for none x in (1.0, 2.0, 3.0) : (x > 4.0)"#);
+
+    // https://github.com/VirusTotal/yara-x/issues/87
+    #[cfg(feature = "test_proto2-module")]
+    condition_true!(
+        r#"not for any i in (0..test_proto2.int64_undef) : (true)"#
+    );
 }
 
 #[test]