[WebAssembly] Add -wasm-use-legacy-eh option (#122158)

This replaces the existing `-wasm-enable-exnref` with
`-wasm-use-legacy-eh` option, in an effort to make the new standardized
exnref proposal the 'default' state and the legacy proposal needs to be
separately enabled an option. But given that most users haven't switched
to the new proposal and major web browsers haven't turned it on by
default, this `-wasm-use-legacy-eh` is turned on by default, so nothing
will change for now for the functionality perspective.

This also removes the restriction that `-wasm-enable-exnref` be only
used with `-wasm-enable-eh` because this option is enabled by default.
This option does not have any effect when `-wasm-enable-eh` is not used.

1 files changed, 1 insertions, 4 deletions

diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp
index 9c95d73..ba8c479 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp
@@ -400,8 +400,8 @@ FunctionPass *WebAssemblyPassConfig::createTargetRegisterAllocator(bool) {
 using WebAssembly::WasmEnableEH;
 using WebAssembly::WasmEnableEmEH;
 using WebAssembly::WasmEnableEmSjLj;
-using WebAssembly::WasmEnableExnref;
 using WebAssembly::WasmEnableSjLj;
+using WebAssembly::WasmUseLegacyEH;
 
 static void basicCheckForEHAndSjLj(TargetMachine *TM) {
 
@@ -417,9 +417,6 @@ static void basicCheckForEHAndSjLj(TargetMachine *TM) {
   if (WasmEnableEmEH && WasmEnableSjLj)
     report_fatal_error(
         "-enable-emscripten-cxx-exceptions not allowed with -wasm-enable-sjlj");
-  if (WasmEnableExnref && !WasmEnableEH)
-    report_fatal_error(
-        "-wasm-enable-exnref should be used with -wasm-enable-eh");
 
   // Here we make sure TargetOptions.ExceptionModel is the same as
   // MCAsmInfo.ExceptionsType. Normally these have to be the same, because clang