[clang codegen] Add CreateRuntimeFunction overload that takes a clang type. (#113506)

Correctly computing the LLVM types/attributes is complicated in general,
so add a variant which does that for you.

1 files changed, 49 insertions, 15 deletions

diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index ba376f9..e1537e8 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -4903,6 +4903,52 @@ GetRuntimeFunctionDecl(ASTContext &C, StringRef Name) {
   return nullptr;
 }
 
+static void setWindowsItaniumDLLImport(CodeGenModule &CGM, bool Local,
+                                       llvm::Function *F, StringRef Name) {
+  // In Windows Itanium environments, try to mark runtime functions
+  // dllimport. For Mingw and MSVC, don't. We don't really know if the user
+  // will link their standard library statically or dynamically. Marking
+  // functions imported when they are not imported can cause linker errors
+  // and warnings.
+  if (!Local && CGM.getTriple().isWindowsItaniumEnvironment() &&
+      !CGM.getCodeGenOpts().LTOVisibilityPublicStd) {
+    const FunctionDecl *FD = GetRuntimeFunctionDecl(CGM.getContext(), Name);
+    if (!FD || FD->hasAttr<DLLImportAttr>()) {
+      F->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
+      F->setLinkage(llvm::GlobalValue::ExternalLinkage);
+    }
+  }
+}
+
+llvm::FunctionCallee CodeGenModule::CreateRuntimeFunction(
+    QualType ReturnTy, ArrayRef<QualType> ArgTys, StringRef Name,
+    llvm::AttributeList ExtraAttrs, bool Local, bool AssumeConvergent) {
+  if (AssumeConvergent) {
+    ExtraAttrs =
+        ExtraAttrs.addFnAttribute(VMContext, llvm::Attribute::Convergent);
+  }
+
+  QualType FTy = Context.getFunctionType(ReturnTy, ArgTys,
+                                         FunctionProtoType::ExtProtoInfo());
+  const CGFunctionInfo &Info = getTypes().arrangeFreeFunctionType(
+      Context.getCanonicalType(FTy).castAs<FunctionProtoType>());
+  auto *ConvTy = getTypes().GetFunctionType(Info);
+  llvm::Constant *C = GetOrCreateLLVMFunction(
+      Name, ConvTy, GlobalDecl(), /*ForVTable=*/false,
+      /*DontDefer=*/false, /*IsThunk=*/false, ExtraAttrs);
+
+  if (auto *F = dyn_cast<llvm::Function>(C)) {
+    if (F->empty()) {
+      SetLLVMFunctionAttributes(GlobalDecl(), Info, F, /*IsThunk*/ false);
+      // FIXME: Set calling-conv properly in ExtProtoInfo
+      F->setCallingConv(getRuntimeCC());
+      setWindowsItaniumDLLImport(*this, Local, F, Name);
+      setDSOLocal(F);
+    }
+  }
+  return {ConvTy, C};
+}
+
 /// CreateRuntimeFunction - Create a new runtime function with the specified
 /// type and name.
 llvm::FunctionCallee
@@ -4922,24 +4968,12 @@ CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy, StringRef Name,
   if (auto *F = dyn_cast<llvm::Function>(C)) {
     if (F->empty()) {
       F->setCallingConv(getRuntimeCC());
-
-      // In Windows Itanium environments, try to mark runtime functions
-      // dllimport. For Mingw and MSVC, don't. We don't really know if the user
-      // will link their standard library statically or dynamically. Marking
-      // functions imported when they are not imported can cause linker errors
-      // and warnings.
-      if (!Local && getTriple().isWindowsItaniumEnvironment() &&
-          !getCodeGenOpts().LTOVisibilityPublicStd) {
-        const FunctionDecl *FD = GetRuntimeFunctionDecl(Context, Name);
-        if (!FD || FD->hasAttr<DLLImportAttr>()) {
-          F->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
-          F->setLinkage(llvm::GlobalValue::ExternalLinkage);
-        }
-      }
+      setWindowsItaniumDLLImport(*this, Local, F, Name);
       setDSOLocal(F);
       // FIXME: We should use CodeGenModule::SetLLVMFunctionAttributes() instead
       // of trying to approximate the attributes using the LLVM function
-      // signature. This requires revising the API of CreateRuntimeFunction().
+      // signature.  The other overload of CreateRuntimeFunction does this; it
+      // should be used for new code.
       markRegisterParameterAttributes(F);
     }
   }