From a317958d3026632dcdeda5cc9850fd79dda59e9d Mon Sep 17 00:00:00 2001 From: Heejin Ahn Date: Thu, 15 Jun 2023 17:20:28 -0700 Subject: [EH] Add pass to remove EH instructions (#5770) This pass strips all EH stuff, including EH instructions and tags, from the input module and disables the EH feature from the features section. 1. This removes `catch` and `catch_all` blocks from the code. So ```wast (try (do (some code) ) (catch ... ) ) ``` becomes just `(some code)`. Note that all `rethrow`s will be removed with `catch`es. Note that all `rethrow`s will be removed with `catch`es. 2. This converts 'throw (...)` into `unreachable`. Note that `rethrows 3. This removes all tags from the module, which are unused anyway after 1 and 2. 4. This removes exception handling feature from the features section. You can use the pass with ```console $ wasm-opt --enable-exception-handling --strip-eh INPUT -o OUTPUT ``` This is not an optimization pass, so it is not run unless you specify the pass explicitly. This is in effect similar to Clang's `-fignore-exceptions`, in which you can throw but it will result in a crash and we compile away all landing pads. This can be used for people who don't (or can't) use `-fignore-exceptions` in their build settings or who want to compile away `catch` blocks later. Closes emscripten-core/emscripten#19585. --- test/lit/help/wasm-opt.test | 2 ++ test/lit/help/wasm2js.test | 2 ++ 2 files changed, 4 insertions(+) (limited to 'test/lit/help') diff --git a/test/lit/help/wasm-opt.test b/test/lit/help/wasm-opt.test index 2e10ed073..30369e62f 100644 --- a/test/lit/help/wasm-opt.test +++ b/test/lit/help/wasm-opt.test @@ -452,6 +452,8 @@ ;; CHECK-NEXT: ;; CHECK-NEXT: --strip-dwarf strip dwarf debug info ;; CHECK-NEXT: +;; CHECK-NEXT: --strip-eh strip EH instructions +;; CHECK-NEXT: ;; CHECK-NEXT: --strip-producers strip the wasm producers section ;; CHECK-NEXT: ;; CHECK-NEXT: --strip-target-features strip the wasm target features diff --git a/test/lit/help/wasm2js.test b/test/lit/help/wasm2js.test index 1766d771d..916dbbb4d 100644 --- a/test/lit/help/wasm2js.test +++ b/test/lit/help/wasm2js.test @@ -411,6 +411,8 @@ ;; CHECK-NEXT: ;; CHECK-NEXT: --strip-dwarf strip dwarf debug info ;; CHECK-NEXT: +;; CHECK-NEXT: --strip-eh strip EH instructions +;; CHECK-NEXT: ;; CHECK-NEXT: --strip-producers strip the wasm producers section ;; CHECK-NEXT: ;; CHECK-NEXT: --strip-target-features strip the wasm target features -- cgit v1.2.3