[CIR][Lowering] Set linkage type for LLVM functions.

Author: htyu

clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp

@@ -60,6 +60,34 @@ using namespace llvm;
 namespace cir {
 namespace direct {
 
+mlir::LLVM::Linkage convertLinkage(mlir::cir::GlobalLinkageKind linkage) {
+  using CIR = mlir::cir::GlobalLinkageKind;
+  using LLVM = mlir::LLVM::Linkage;
+
+  switch (linkage) {
+  case CIR::AvailableExternallyLinkage:
+    return LLVM::AvailableExternally;
+  case CIR::CommonLinkage:
+    return LLVM::Common;
+  case CIR::ExternalLinkage:
+    return LLVM::External;
+  case CIR::ExternalWeakLinkage:
+    return LLVM::ExternWeak;
+  case CIR::InternalLinkage:
+    return LLVM::Internal;
+  case CIR::LinkOnceAnyLinkage:
+    return LLVM::Linkonce;
+  case CIR::LinkOnceODRLinkage:
+    return LLVM::LinkonceODR;
+  case CIR::PrivateLinkage:
+    return LLVM::Private;
+  case CIR::WeakAnyLinkage:
+    return LLVM::Weak;
+  case CIR::WeakODRLinkage:
+    return LLVM::WeakODR;
+  };
+}
+
 class CIRPtrStrideOpLowering
     : public mlir::OpConversionPattern<mlir::cir::PtrStrideOp> {
 public:
@@ -276,12 +304,12 @@ class CIRCastOpLowering : public mlir::OpConversionPattern<mlir::cir::CastOp> {
       auto llvmSrcVal = adaptor.getOperands().front();
       auto llvmDstTy = getTypeConverter()->convertType(dstTy);
       auto kind = mlir::LLVM::FCmpPredicate::une;
-      
+
       // Check if float is not equal to zero.
       auto zeroFloat = rewriter.create<mlir::LLVM::ConstantOp>(
           castOp.getLoc(), llvmSrcVal.getType(),
           mlir::FloatAttr::get(llvmSrcVal.getType(), 0.0));
-      
+
       // Extend comparison result to either bool (C++) or int (C).
       mlir::Value cmpResult = rewriter.create<mlir::LLVM::FCmpOp>(
           castOp.getLoc(), kind, llvmSrcVal, zeroFloat);
@@ -662,8 +690,9 @@ class CIRFuncLowering : public mlir::OpConversionPattern<mlir::cir::FuncOp> {
       Loc = FusedLoc.getLocations()[0];
     }
     assert(Loc.isa<mlir::FileLineColLoc>() && "expected single location here");
-    auto fn =
-        rewriter.create<mlir::LLVM::LLVMFuncOp>(Loc, op.getName(), llvmFnTy);
+    auto linkage = convertLinkage(op.getLinkage());
+    auto fn = rewriter.create<mlir::LLVM::LLVMFuncOp>(Loc, op.getName(),
+                                                      llvmFnTy, linkage);
 
     rewriter.inlineRegionBefore(op.getBody(), fn.getBody(), fn.end());
     if (failed(rewriter.convertRegionTypes(&fn.getBody(), *typeConverter,
@@ -709,34 +738,6 @@ lowerConstArrayAttr(mlir::cir::ConstArrayAttr constArr,
   return std::nullopt;
 }
 
-mlir::LLVM::Linkage convertLinkage(mlir::cir::GlobalLinkageKind linkage) {
-  using CIR = mlir::cir::GlobalLinkageKind;
-  using LLVM = mlir::LLVM::Linkage;
-
-  switch (linkage) {
-  case CIR::AvailableExternallyLinkage:
-    return LLVM::AvailableExternally;
-  case CIR::CommonLinkage:
-    return LLVM::Common;
-  case CIR::ExternalLinkage:
-    return LLVM::External;
-  case CIR::ExternalWeakLinkage:
-    return LLVM::ExternWeak;
-  case CIR::InternalLinkage:
-    return LLVM::Internal;
-  case CIR::LinkOnceAnyLinkage:
-    return LLVM::Linkonce;
-  case CIR::LinkOnceODRLinkage:
-    return LLVM::LinkonceODR;
-  case CIR::PrivateLinkage:
-    return LLVM::Private;
-  case CIR::WeakAnyLinkage:
-    return LLVM::Weak;
-  case CIR::WeakODRLinkage:
-    return LLVM::WeakODR;
-  };
-}
-
 class CIRGetGlobalOpLowering
     : public mlir::OpConversionPattern<mlir::cir::GetGlobalOp> {
 public:

clang/test/CIR/CodeGen/linkage.c

@@ -0,0 +1,19 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir-enable -emit-cir %s -o %t.cir
+// RUN: FileCheck --input-file=%t.cir %s -check-prefix=CIR
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir-enable -emit-llvm %s -o %t.ll
+// RUN: FileCheck --input-file=%t.ll %s -check-prefix=LLVM
+
+
+static int bar(int i) {
+  return i;
+}
+
+int foo() {
+  return bar(5);
+}
+
+// CIR:   cir.func internal private @bar(
+// CIR:   cir.func @foo(
+
+// LLVM: define internal i32 @bar(
+// LLVM: define i32 @foo(