[clang] [lld] [llvm] [WebAssembly] WASIP3 and component model threading support (PR #175800)

[Sy Brand via llvm-commits]

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@@ -407,10 +418,11 @@ WebAssemblyTargetInfo::getTargetBuiltins() const {
 void WebAssemblyTargetInfo::adjust(DiagnosticsEngine &Diags, LangOptions &Opts,
                                    const TargetInfo *Aux) {
   TargetInfo::adjust(Diags, Opts, Aux);
-  // Turn off POSIXThreads and ThreadModel so that we don't predefine _REENTRANT
-  // or __STDCPP_THREADS__ if we will eventually end up stripping atomics
-  // because they are unsupported.
-  if (!HasAtomics || !HasBulkMemory) {
+  // If not using component model threading intrinsics, turn off POSIXThreads 
+  // and ThreadModel so that we don't predefine _REENTRANT or __STDCPP_THREADS__ 
+  // if we will eventually end up stripping atomics because they are unsupported.
+  if (!HasComponentModelThreadContext &&
+      (!HasAtomics || !HasBulkMemory)) {
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TartanLlama wrote:

Yeah I don't see a strong reason to disallow it. Maybe you're compiling some code that uses atomics and targeting WASIp3; the operations don't *need* to be atomic, but we shouldn't necessitate making code changes just to save them cycles

https://github.com/llvm/llvm-project/pull/175800