Merge pull request #85514 from DougGregor/asmname-c-fixes-6.3

[6.3] SIL `asmname`, `@c` serialization, and calling-convention fixes

Author: DougGregor

lib/ClangImporter/ClangImporter.cpp

@@ -4766,8 +4766,10 @@ void ClangImporter::Implementation::getMangledName(
     auto ctorGlobalDecl =
         clang::GlobalDecl(ctor, clang::CXXCtorType::Ctor_Complete);
     mangler->mangleCXXName(ctorGlobalDecl, os);
-  } else {
+  } else if (mangler->shouldMangleDeclName(clangDecl)) {
     mangler->mangleName(clangDecl, os);
+  } else {
+    os << clangDecl->getName();
   }
 }
 

lib/LLVMPasses/LLVMARCContract.cpp

@@ -403,6 +403,11 @@ void SwiftARCContract::getAnalysisUsage(llvm::AnalysisUsage &AU) const {
 llvm::PreservedAnalyses
 SwiftARCContractPass::run(llvm::Function &F,
                           llvm::FunctionAnalysisManager &AM) {
+  // Don't touch those functions that implement reference counting in the
+  // runtime.
+  if (!allowArcOptimizations(F.getName()))
+    return PreservedAnalyses::all();
+
   bool changed = SwiftARCContractImpl(F).run();
   if (!changed)
     return PreservedAnalyses::all();

lib/LLVMPasses/LLVMARCOpts.cpp

@@ -1015,6 +1015,12 @@ void SwiftARCOpt::getAnalysisUsage(llvm::AnalysisUsage &AU) const {
 
 static bool runSwiftARCOpts(Function &F, SwiftRCIdentity &RC) {
   bool Changed = false;
+
+  // Don't touch those functions that implement reference counting in the
+  // runtime.
+  if (!allowArcOptimizations(F.getName()))
+    return Changed;
+
   ARCEntryPointBuilder B(F);
 
   // First thing: canonicalize swift_retain and similar calls so that nothing

lib/LLVMPasses/LLVMARCOpts.h

@@ -26,6 +26,62 @@ enum RT_Kind {
 #include "LLVMSwift.def"
 };
 
+inline RT_Kind classifyFunctionName(StringRef name) {
+  return llvm::StringSwitch<RT_Kind>(name)
+#define SWIFT_FUNC(Name, MemBehavior, TextualName) \
+    .Case("swift_" #TextualName, RT_ ## Name)
+#define SWIFT_INTERNAL_FUNC_NEVER_NONATOMIC(Name, MemBehavior, TextualName) \
+    .Case("__swift_" #TextualName, RT_ ## Name)
+#include "LLVMSwift.def"
+
+    // Identify "Client" versions of reference counting entry points.
+#define SWIFT_FUNC(Name, MemBehavior, TextualName) \
+    .Case("swift_" #TextualName "Client", RT_ ## Name)
+#define SWIFT_INTERNAL_FUNC_NEVER_NONATOMIC(Name, MemBehavior, TextualName) \
+    .Case("__swift_" #TextualName "Client", RT_ ## Name)
+#include "LLVMSwift.def"
+
+    // Support non-atomic versions of reference counting entry points.
+#define SWIFT_FUNC(Name, MemBehavior, TextualName) \
+    .Case("swift_nonatomic_" #TextualName, RT_ ## Name)
+#define OBJC_FUNC(Name, MemBehavior, TextualName) \
+    .Case("objc_nonatomic_" #TextualName, RT_ ## Name)
+#define SWIFT_INTERNAL_FUNC_NEVER_NONATOMIC(Name, MemBehavior, TextualName)
+#include "LLVMSwift.def"
+
+    .Default(RT_Unknown);
+}
+
+/// Whether to allow ARC optimizations for a function with the given name.
+inline bool allowArcOptimizations(StringRef name) {
+  switch (classifyFunctionName(name)) {
+  case RT_UnknownObjectRetainN:
+  case RT_BridgeRetainN:
+  case RT_RetainN:
+  case RT_UnknownObjectReleaseN:
+  case RT_BridgeReleaseN:
+  case RT_ReleaseN:
+  case RT_UnknownObjectRetain:
+  case RT_UnknownObjectRelease:
+  case RT_Retain:
+  case RT_ObjCRetain:
+  case RT_ObjCRelease:
+  case RT_RetainUnowned:
+  case RT_Release:
+  case RT_BridgeRetain:
+  case RT_BridgeRelease:
+    return false;
+
+  case RT_Unknown:
+  case RT_NoMemoryAccessed:
+  case RT_CheckUnowned:
+  case RT_AllocObject:
+  case RT_FixLifetime:
+  case RT_EndBorrow:
+    return true;
+  }
+}
+
 /// Take a look at the specified instruction and classify it into what kind of
 /// runtime entrypoint it is, if any.
 inline RT_Kind classifyInstruction(const llvm::Instruction &I) {
@@ -57,29 +113,7 @@ inline RT_Kind classifyInstruction(const llvm::Instruction &I) {
   if (F == nullptr)
     return RT_Unknown;
 
-  return llvm::StringSwitch<RT_Kind>(F->getName())
-#define SWIFT_FUNC(Name, MemBehavior, TextualName) \
-    .Case("swift_" #TextualName, RT_ ## Name)
-#define SWIFT_INTERNAL_FUNC_NEVER_NONATOMIC(Name, MemBehavior, TextualName) \
-    .Case("__swift_" #TextualName, RT_ ## Name)
-#include "LLVMSwift.def"
-
-    // Identify "Client" versions of reference counting entry points.
-#define SWIFT_FUNC(Name, MemBehavior, TextualName) \
-    .Case("swift_" #TextualName "Client", RT_ ## Name)
-#define SWIFT_INTERNAL_FUNC_NEVER_NONATOMIC(Name, MemBehavior, TextualName) \
-    .Case("__swift_" #TextualName "Client", RT_ ## Name)
-#include "LLVMSwift.def"
-
-    // Support non-atomic versions of reference counting entry points.
-#define SWIFT_FUNC(Name, MemBehavior, TextualName) \
-    .Case("swift_nonatomic_" #TextualName, RT_ ## Name)
-#define OBJC_FUNC(Name, MemBehavior, TextualName) \
-    .Case("objc_nonatomic_" #TextualName, RT_ ## Name)
-#define SWIFT_INTERNAL_FUNC_NEVER_NONATOMIC(Name, MemBehavior, TextualName)
-#include "LLVMSwift.def"
-
-    .Default(RT_Unknown);
+  return classifyFunctionName(F->getName());
 }
 
 } // end namespace swift

lib/SIL/IR/SILDeclRef.cpp

@@ -1025,7 +1025,8 @@ SerializedKind_t SILDeclRef::getSerializedKind() const {
     // @objc thunks for top-level functions are serializable since they're
     // referenced from @convention(c) conversions inside inlinable
     // functions.
-    return IsSerialized;
+    if (isThunk())
+      return IsSerialized;
   }
 
   // Declarations imported from Clang modules are serialized if

lib/SIL/IR/SILFunctionType.cpp

@@ -4424,12 +4424,29 @@ TypeConverter::getDeclRefRepresentation(SILDeclRef c) {
     if (!c.hasDecl())
       return SILFunctionTypeRepresentation::CFunctionPointer;
 
-    if (auto method =
-            dyn_cast_or_null<clang::CXXMethodDecl>(c.getDecl()->getClangDecl()))
-      return isa<clang::CXXConstructorDecl>(method) || method->isStatic()
-                 ? SILFunctionTypeRepresentation::CFunctionPointer
-                 : SILFunctionTypeRepresentation::CXXMethod;
+    if (auto clangDecl = c.getDecl()->getClangDecl()) {
+      if (auto method = dyn_cast<clang::CXXMethodDecl>(clangDecl)) {
+        return isa<clang::CXXConstructorDecl>(method) || method->isStatic()
+                   ? SILFunctionTypeRepresentation::CFunctionPointer
+                   : SILFunctionTypeRepresentation::CXXMethod;
+      }
+
+      if (auto function = dyn_cast<clang::FunctionDecl>(clangDecl)) {
+        if (auto fnType = function->getType()->getAs<clang::FunctionType>()) {
+          switch (fnType->getCallConv()) {
+            case clang::CC_Swift:
+              return SILFunctionTypeRepresentation::Thin;
 
+            case clang::CC_C:
+              return SILFunctionTypeRepresentation::CFunctionPointer;
+
+            default:
+              // Fall back to heuristics below.
+              break;
+          }
+        }
+      }
+    }
 
     // For example, if we have a function in a namespace:
     if (c.getDecl()->isImportAsMember())