2 files changed, 17 insertions, 0 deletions
diff --git a/clang/lib/Basic/Targets/WebAssembly.cpp b/clang/lib/Basic/Targets/WebAssembly.cpp
index af25d25..e362350e 100644
--- a/clang/lib/Basic/Targets/WebAssembly.cpp
+++ b/clang/lib/Basic/Targets/WebAssembly.cpp
@@ -64,6 +64,7 @@ bool WebAssemblyTargetInfo::hasFeature(StringRef Feature) const {
       .Case("mutable-globals", HasMutableGlobals)
       .Case("nontrapping-fptoint", HasNontrappingFPToInt)
       .Case("reference-types", HasReferenceTypes)
+      .Case("gc", HasGC)
       .Case("relaxed-simd", SIMDLevel >= RelaxedSIMD)
       .Case("sign-ext", HasSignExt)
       .Case("simd128", SIMDLevel >= SIMD128)
@@ -106,6 +107,8 @@ void WebAssemblyTargetInfo::getTargetDefines(const LangOptions &Opts,
     Builder.defineMacro("__wasm_nontrapping_fptoint__");
   if (HasReferenceTypes)
     Builder.defineMacro("__wasm_reference_types__");
+  if (HasGC)
+    Builder.defineMacro("__wasm_gc__");
   if (SIMDLevel >= RelaxedSIMD)
     Builder.defineMacro("__wasm_relaxed_simd__");
   if (HasSignExt)
@@ -307,6 +310,14 @@ bool WebAssemblyTargetInfo::handleTargetFeatures(
       HasReferenceTypes = false;
       continue;
     }
+    if (Feature == "+gc") {
+      HasGC = true;
+      continue;
+    }
+    if (Feature == "-gc") {
+      HasGC = false;
+      continue;
+    }
     if (Feature == "+relaxed-simd") {
       SIMDLevel = std::max(SIMDLevel, RelaxedSIMD);
       continue;
@@ -353,6 +364,11 @@ bool WebAssemblyTargetInfo::handleTargetFeatures(
     return false;
   }
 
+  // gc implies reference-types
+  if (HasGC) {
+    HasReferenceTypes = true;
+  }
+
   // bulk-memory-opt is a subset of bulk-memory.
   if (HasBulkMemory) {
     HasBulkMemoryOpt = true;
diff --git a/clang/lib/Basic/Targets/WebAssembly.h b/clang/lib/Basic/Targets/WebAssembly.h
index 57b366c..c47c8cc 100644
--- a/clang/lib/Basic/Targets/WebAssembly.h
+++ b/clang/lib/Basic/Targets/WebAssembly.h
@@ -69,6 +69,7 @@ class LLVM_LIBRARY_VISIBILITY WebAssemblyTargetInfo : public TargetInfo {
   bool HasMutableGlobals = false;
   bool HasNontrappingFPToInt = false;
   bool HasReferenceTypes = false;
+  bool HasGC = false;
   bool HasSignExt = false;
   bool HasTailCall = false;
   bool HasWideArithmetic = false;