fuzz: allows compiler=stackoverflow,intp=unreachable (#1779)

Signed-off-by: Takeshi Yoneda <t.y.mathetake@gmail.com>

internal/engine/wazevo/wazevoapi/debug_options.go

@@ -60,7 +60,11 @@ const (
 func CheckStackGuardPage(s []byte) {
 	for i := 0; i < StackGuardCheckGuardPageSize; i++ {
 		if s[i] != 0 {
-			panic(fmt.Sprintf("BUG: stack guard page is corrupted: %s", hex.EncodeToString(s[:StackGuardCheckGuardPageSize])))
+			panic(
+				fmt.Sprintf("BUG: stack guard page is corrupted:\n\tguard_page=%s\n\tstack=%s",
+					hex.EncodeToString(s[:StackGuardCheckGuardPageSize]),
+					hex.EncodeToString(s[StackGuardCheckGuardPageSize:]),
+				))
 		}
 	}
 }

internal/integration_test/fuzz/fuzz/fuzz_targets/wazero_abi.rs

@@ -1,7 +1,5 @@
 //! This module provides the functions implemented by wazero via CGo.
 
-use wasm_smith::SwarmConfig;
-
 extern "C" {
     // require_no_diff is implemented in Go, and accepts the pointer to the binary and its size.
     #[allow(dead_code)]

internal/integration_test/fuzz/wazerolib/nodiff.go

@@ -314,6 +314,12 @@ func ensureInvocationError(compilerErr, interpErr error) error {
 		interpErrMsg = interpErrMsg[:strings.Index(interpErrMsg, "\n")]
 	}
 
+	if strings.Contains(compilerErrMsg, "stack overflow") && strings.Contains(interpErrMsg, "unreachable") {
+		// Compiler is more likely to reach stack overflow than interpreter, so we allow this case. This case is most likely
+		// that interpreter reached the unreachable out of "fuel".
+		return nil
+	}
+
 	if compilerErrMsg != interpErrMsg {
 		return fmt.Errorf("error mismatch:\n\tinterpreter: %v\n\tcompiler: %v", interpErr, compilerErr)
 	}