Don't dllimport inline functions when targeting MinGW (PR21366)

It turns out that MinGW never dllimports of exports inline functions.
This means that code compiled with Clang would fail to link with
MinGW-compiled libraries since we might try to import functions that
are not imported.

To fix this, make Clang never dllimport inline functions when targeting
MinGW.

llvm-svn: 221154

1 files changed, 8 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 4262377..7ecd95e 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -2003,6 +2003,8 @@ void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) {
     GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass);
   else if (D->hasAttr<DLLExportAttr>())
     GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass);
+  else
+    GV->setDLLStorageClass(llvm::GlobalVariable::DefaultStorageClass);
 
   if (Linkage == llvm::GlobalVariable::CommonLinkage)
     // common vars aren't constant even if declared const.
@@ -2338,6 +2340,12 @@ void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD,
   // declarations).
   auto *Fn = cast<llvm::Function>(GV);
   setFunctionLinkage(GD, Fn);
+  if (D->hasAttr<DLLImportAttr>())
+    GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass);
+  else if (D->hasAttr<DLLExportAttr>())
+    GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass);
+  else
+    GV->setDLLStorageClass(llvm::GlobalVariable::DefaultStorageClass);
 
   // FIXME: this is redundant with part of setFunctionDefinitionAttributes
   setGlobalVisibility(Fn, D);