[clang] 47039a1 - [WebAssembly] Remove restriction on main name mangling

[Sam Clegg via cfe-commits]

Author: Sam Clegg
Date: 2022-06-06T14:04:27-07:00
New Revision: 47039a1a4b299c01dfa0ec531fbc0d24718bb8eb

URL: https://github.com/llvm/llvm-project/commit/47039a1a4b299c01dfa0ec531fbc0d24718bb8eb
DIFF: https://github.com/llvm/llvm-project/commit/47039a1a4b299c01dfa0ec531fbc0d24718bb8eb.diff

LOG: [WebAssembly] Remove restriction on main name mangling

Summary: Emscripten now handles/supports this new mode.

Subscribers: dschuff, jgravelle-google, aheejin, sunfish, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D75277

Added: 
    

Modified: 
    clang/lib/AST/Mangle.cpp
    clang/lib/CodeGen/CodeGenModule.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/AST/Mangle.cpp b/clang/lib/AST/Mangle.cpp
index 984da9909ce23..c1a345390091b 100644
--- a/clang/lib/AST/Mangle.cpp
+++ b/clang/lib/AST/Mangle.cpp
@@ -70,9 +70,7 @@ static CCMangling getCallingConvMangling(const ASTContext &Context,
 
   // On wasm, the argc/argv form of "main" is renamed so that the startup code
   // can call it with the correct function signature.
-  // On Emscripten, users may be exporting "main" and expecting to call it
-  // themselves, so we can't mangle it.
-  if (Triple.isWasm() && !Triple.isOSEmscripten())
+  if (Triple.isWasm())
     if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND))
       if (FD->isMain() && FD->hasPrototype() && FD->param_size() == 2)
         return CCM_WasmMainArgcArgv;

diff  --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index afb28c1e5cc97..c3507fad0d79d 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -554,10 +554,8 @@ void CodeGenModule::Release() {
     CodeGenFunction(*this).EmitCfiCheckStub();
   }
   emitAtAvailableLinkGuard();
-  if (Context.getTargetInfo().getTriple().isWasm() &&
-      !Context.getTargetInfo().getTriple().isOSEmscripten()) {
+  if (Context.getTargetInfo().getTriple().isWasm())
     EmitMainVoidAlias();
-  }
 
   if (getTriple().isAMDGPU()) {
     // Emit reference of __amdgpu_device_library_preserve_asan_functions to
@@ -6352,8 +6350,10 @@ void CodeGenModule::EmitMainVoidAlias() {
   // new-style no-argument main is in used.
   if (llvm::Function *F = getModule().getFunction("main")) {
     if (!F->isDeclaration() && F->arg_size() == 0 && !F->isVarArg() &&
-        F->getReturnType()->isIntegerTy(Context.getTargetInfo().getIntWidth()))
-      addUsedGlobal(llvm::GlobalAlias::create("__main_void", F));
+        F->getReturnType()->isIntegerTy(Context.getTargetInfo().getIntWidth())) {
+      auto *GA = llvm::GlobalAlias::create("__main_void", F);
+      GA->setVisibility(llvm::GlobalValue::HiddenVisibility);
+    }
   }
 }