From 0a2a59fae573c2d793501720a2faf986118ee4f4 Mon Sep 17 00:00:00 2001 From: "Soni L." Date: Mon, 23 Sep 2024 17:01:18 -0300 Subject: wasm2c: Use wrappers for function references (#2465) Clang 17(?) tightened UBSAN checks, so that you now get this: ``` - test/wasm2c/spec/call_indirect.txt expected error code 0, got 1. STDERR MISMATCH: --- expected +++ actual @@ -0,0 +1,3 @@ +out/test/wasm2c/spec/call_indirect/call_indirect.0.c:2144:12: runtime error: call to function w2c_call__indirect__0__wasm_f0 through pointer to incorrect function type 'unsigned int (*)(void *)' +/home/runner/work/wabt/wabt/out/test/wasm2c/spec/call_indirect/call_indirect.0.c:1925: note: w2c_call__indirect__0__wasm_f0 defined here +SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior out/test/wasm2c/spec/call_indirect/call_indirect.0.c:2144:12 STDOUT MISMATCH: --- expected +++ actual @@ -1 +0,0 @@ -134/134 tests passed. ``` This happens because emitted functions use a typed module instance, while function references use a `void*` instance. It is UB in C to call the former with the latter, so clang is correct here. We had to pick one of two ways to fix this: either emit `void*` wrapper functions that do the appropriate downcasting for any module functions that go into a table (potentially including imported functions), or the approach that takes significantly less effort of changing everything to `void*` and downcasting internally. ~~We obviously chose the latter.~~ We eventually started emitting wrapper functions. --- .github/workflows/build.yml | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to '.github') diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml index 92b5a088..99ffb6eb 100644 --- a/.github/workflows/build.yml +++ b/.github/workflows/build.yml @@ -99,7 +99,7 @@ jobs: sanitize: name: sanitize - runs-on: ubuntu-latest + runs-on: ubuntu-24.04 env: USE_NINJA: "1" CC: "clang" -- cgit v1.2.3