MS compatibility: always emit dllexported in-class initialized static data members...

This makes us emit dllexported in-class initialized static data members (which
are treated as definitions in MSVC), even when they're not referenced.

It also makes their special linkage reflected in the GVA linkage instead of
getting massaged in CodeGen.

Differential Revision: http://reviews.llvm.org/D4563

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@213304 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/AST/ASTContext.h b/include/clang/AST/ASTContext.h
index 0a991cc4cee9e8b095b81f36c26cc455b4b5fcd5..8134f6b080b7e72a811a9527bbaa1017ae1ca122 100644 (file)
--- a/include/clang/AST/ASTContext.h
+++ b/include/clang/AST/ASTContext.h
@@ -2283,6 +2283,10 @@ public:
   void getObjCEncodingForMethodParameter(Decl::ObjCDeclQualifier QT,
                                          QualType T, std::string& S,
                                          bool Extended) const;
+
+  /// \brief Returns true if this is an inline-initialized static data member
+  /// which is treated as a definition for MSVC compatibility.
+  bool isMSStaticDataMemberInlineDefinition(const VarDecl *VD) const;
   
 private:
   const ASTRecordLayout &

diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index 5c271f027fe175be28b14dc7b248ed90778cfa0a..bccdae91d2ebcb91ed48426845c0d097a8016b57 100644 (file)
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -4781,6 +4781,12 @@ CharUnits ASTContext::getObjCEncodingTypeSize(QualType type) const {
   return sz;
 }
 
+bool ASTContext::isMSStaticDataMemberInlineDefinition(const VarDecl *VD) const {
+  return getLangOpts().MSVCCompat && VD->isStaticDataMember() &&
+         VD->getType()->isIntegralOrEnumerationType() &&
+         !VD->getFirstDecl()->isOutOfLine() && VD->getFirstDecl()->hasInit();
+}
+
 static inline 
 std::string charUnitsToString(const CharUnits &CU) {
   return llvm::itostr(CU.getQuantity());
@@ -7849,6 +7855,12 @@ static GVALinkage basicGVALinkageForVariable(const ASTContext &Context,
                                                : StaticLocalLinkage;
   }
 
+  // MSVC treats in-class initialized static data members as definitions.
+  // By giving them non-strong linkage, out-of-line definitions won't
+  // cause link errors.
+  if (Context.isMSStaticDataMemberInlineDefinition(VD))
+    return GVA_DiscardableODR;
+
   switch (VD->getTemplateSpecializationKind()) {
   case TSK_Undeclared:
   case TSK_ExplicitSpecialization:
@@ -7934,7 +7946,8 @@ bool ASTContext::DeclMustBeEmitted(const Decl *D) {
   const VarDecl *VD = cast<VarDecl>(D);
   assert(VD->isFileVarDecl() && "Expected file scoped var");
 
-  if (VD->isThisDeclarationADefinition() == VarDecl::DeclarationOnly)
+  if (VD->isThisDeclarationADefinition() == VarDecl::DeclarationOnly &&
+      !isMSStaticDataMemberInlineDefinition(VD))
     return false;
 
   // Variables that can be needed in other TUs are required.

diff --git a/lib/CodeGen/CGCXXABI.h b/lib/CodeGen/CGCXXABI.h
index b49c68a4df1405398718ae1edc2117adc4361586..91e49707bae683b1b0ee2b09b2b44e083b3cdf32 100644 (file)
--- a/lib/CodeGen/CGCXXABI.h
+++ b/lib/CodeGen/CGCXXABI.h
@@ -403,10 +403,6 @@ public:
   /// Gets the deleted virtual member call name.
   virtual StringRef GetDeletedVirtualCallName() = 0;
 
-  /// \brief Returns true iff static data members that are initialized in the
-  /// class definition should have linkonce linkage.
-  virtual bool isInlineInitializedStaticDataMemberLinkOnce() { return false; }
-
   /**************************** Array cookies ******************************/
 
   /// Returns the extra size required in order to store the array

diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp
index 66ac524f2b9a32d1c008102287ea2935253d046d..6c33f9227926cd9814c11b908306fd36983fc762 100644 (file)
--- a/lib/CodeGen/CodeGenModule.cpp
+++ b/lib/CodeGen/CodeGenModule.cpp
@@ -1256,7 +1256,8 @@ void CodeGenModule::EmitGlobal(GlobalDecl GD) {
     const auto *VD = cast<VarDecl>(Global);
     assert(VD->isFileVarDecl() && "Cannot emit local var decl as global.");
 
-    if (VD->isThisDeclarationADefinition() != VarDecl::Definition)
+    if (VD->isThisDeclarationADefinition() != VarDecl::Definition &&
+        !Context.isMSStaticDataMemberInlineDefinition(VD))
       return;
   }
 
@@ -1592,18 +1593,6 @@ bool CodeGenModule::isTypeConstant(QualType Ty, bool ExcludeCtor) {
   return true;
 }
 
-static bool isVarDeclInlineInitializedStaticDataMember(const VarDecl *VD) {
-  if (!VD->isStaticDataMember())
-    return false;
-  const VarDecl *InitDecl;
-  const Expr *InitExpr = VD->getAnyInitializer(InitDecl);
-  if (!InitExpr)
-    return false;
-  if (InitDecl->isThisDeclarationADefinition())
-    return false;
-  return true;
-}
-
 /// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module,
 /// create and return an llvm GlobalVariable with the specified type.  If there
 /// is something in the module with the specified name, return it potentially
@@ -1666,9 +1655,9 @@ CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName,
 
     // If required by the ABI, treat declarations of static data members with
     // inline initializers as definitions.
-    if (getCXXABI().isInlineInitializedStaticDataMemberLinkOnce() &&
-        isVarDeclInlineInitializedStaticDataMember(D))
+    if (getContext().isMSStaticDataMemberInlineDefinition(D)) {
       EmitGlobalVarDefinition(D);
+    }
 
     // Handle XCore specific ABI requirements.
     if (getTarget().getTriple().getArch() == llvm::Triple::xcore &&
@@ -2087,18 +2076,6 @@ llvm::GlobalValue::LinkageTypes CodeGenModule::getLLVMLinkageForDeclarator(
     return !Context.getLangOpts().AppleKext ? llvm::Function::WeakODRLinkage
                                             : llvm::Function::ExternalLinkage;
 
-  // If required by the ABI, give definitions of static data members with inline
-  // initializers at least linkonce_odr linkage.
-  auto const VD = dyn_cast<VarDecl>(D);
-  if (getCXXABI().isInlineInitializedStaticDataMemberLinkOnce() &&
-      VD && isVarDeclInlineInitializedStaticDataMember(VD)) {
-    if (VD->hasAttr<DLLImportAttr>())
-      return llvm::GlobalValue::AvailableExternallyLinkage;
-    if (VD->hasAttr<DLLExportAttr>())
-      return llvm::GlobalValue::WeakODRLinkage;
-    return llvm::GlobalValue::LinkOnceODRLinkage;
-  }
-
   // C++ doesn't have tentative definitions and thus cannot have common
   // linkage.
   if (!getLangOpts().CPlusPlus && isa<VarDecl>(D) &&

diff --git a/lib/CodeGen/MicrosoftCXXABI.cpp b/lib/CodeGen/MicrosoftCXXABI.cpp
index 41b7574e34c26c3a6b1dd39fae7a8d891158d4d2..a69d4dd3fe86802c6e591da112c6de71ec158f3a 100644 (file)
--- a/lib/CodeGen/MicrosoftCXXABI.cpp
+++ b/lib/CodeGen/MicrosoftCXXABI.cpp
@@ -55,8 +55,6 @@ public:
   // arbitrary.
   StringRef GetDeletedVirtualCallName() override { return "_purecall"; }
 
-  bool isInlineInitializedStaticDataMemberLinkOnce() override { return true; }
-
   llvm::Value *adjustToCompleteObject(CodeGenFunction &CGF,
                                       llvm::Value *ptr,
                                       QualType type) override;

diff --git a/lib/CodeGen/ModuleBuilder.cpp b/lib/CodeGen/ModuleBuilder.cpp
index c4a0e5c063d461978131372ae90f8724fecae42f..c5d18d3286a7b820ddc7efcc6872a5877de6055f 100644 (file)
--- a/lib/CodeGen/ModuleBuilder.cpp
+++ b/lib/CodeGen/ModuleBuilder.cpp
@@ -128,6 +128,19 @@ namespace {
         return;
 
       Builder->UpdateCompletedType(D);
+
+      // For MSVC compatibility, treat declarations of static data members with
+      // inline initializers as definitions.
+      if (Ctx->getLangOpts().MSVCCompat) {
+        for (Decl *Member : D->decls()) {
+          if (VarDecl *VD = dyn_cast<VarDecl>(Member)) {
+            if (Ctx->isMSStaticDataMemberInlineDefinition(VD) &&
+                Ctx->DeclMustBeEmitted(VD)) {
+              Builder->EmitGlobal(VD);
+            }
+          }
+        }
+      }
     }
 
     void HandleTagDeclRequiredDefinition(const TagDecl *D) override {

diff --git a/test/CodeGenCXX/dllexport-members.cpp b/test/CodeGenCXX/dllexport-members.cpp
index 353b952cffe6c69b887361c35206f4c8a2b1656d..79e628ad1840760254317506f18562baf2bbe20c 100644 (file)
--- a/test/CodeGenCXX/dllexport-members.cpp
+++ b/test/CodeGenCXX/dllexport-members.cpp
@@ -1,7 +1,7 @@
-// RUN: %clang_cc1 -triple i686-windows-msvc   -emit-llvm -std=c++1y -O0 -o - %s | FileCheck --check-prefix=MSC --check-prefix=M32 %s
-// RUN: %clang_cc1 -triple x86_64-windows-msvc -emit-llvm -std=c++1y -O0 -o - %s | FileCheck --check-prefix=MSC --check-prefix=M64 %s
-// RUN: %clang_cc1 -triple i686-windows-gnu    -emit-llvm -std=c++1y -O0 -o - %s | FileCheck --check-prefix=GNU --check-prefix=G32 %s
-// RUN: %clang_cc1 -triple x86_64-windows-gnu  -emit-llvm -std=c++1y -O0 -o - %s | FileCheck --check-prefix=GNU --check-prefix=G64 %s
+// RUN: %clang_cc1 -triple i686-windows-msvc -fms-compatibility   -emit-llvm -std=c++1y -O0 -o - %s | FileCheck --check-prefix=MSC --check-prefix=M32 %s
+// RUN: %clang_cc1 -triple x86_64-windows-msvc -fms-compatibility -emit-llvm -std=c++1y -O0 -o - %s | FileCheck --check-prefix=MSC --check-prefix=M64 %s
+// RUN: %clang_cc1 -triple i686-windows-gnu                       -emit-llvm -std=c++1y -O0 -o - %s | FileCheck --check-prefix=GNU --check-prefix=G32 %s
+// RUN: %clang_cc1 -triple x86_64-windows-gnu                     -emit-llvm -std=c++1y -O0 -o - %s | FileCheck --check-prefix=GNU --check-prefix=G64 %s
 
 // Helper structs to make templates more expressive.
 struct ImplicitInst_Exported {};

diff --git a/test/CodeGenCXX/dllimport-members.cpp b/test/CodeGenCXX/dllimport-members.cpp
index 8eab9d4ca5046dbd2290f2ecc64992bf12204ad6..f2986e73a2de57c19eebb830225646367513203f 100644 (file)
--- a/test/CodeGenCXX/dllimport-members.cpp
+++ b/test/CodeGenCXX/dllimport-members.cpp
@@ -1,9 +1,9 @@
-// RUN: %clang_cc1 -triple i686-windows-msvc   -emit-llvm -std=c++1y -O0 -o - %s -DMSABI | FileCheck --check-prefix=MSC --check-prefix=M32 %s
-// RUN: %clang_cc1 -triple x86_64-windows-msvc -emit-llvm -std=c++1y -O0 -o - %s -DMSABI | FileCheck --check-prefix=MSC --check-prefix=M64 %s
-// RUN: %clang_cc1 -triple i686-windows-gnu    -emit-llvm -std=c++1y -O0 -o - %s         | FileCheck --check-prefix=GNU --check-prefix=G32 %s
-// RUN: %clang_cc1 -triple x86_64-windows-gnu  -emit-llvm -std=c++1y -O0 -o - %s         | FileCheck --check-prefix=GNU --check-prefix=G64 %s
-// RUN: %clang_cc1 -triple i686-windows-msvc   -emit-llvm -std=c++1y -O1 -o - %s -DMSABI | FileCheck --check-prefix=MO1 %s
-// RUN: %clang_cc1 -triple i686-windows-gnu    -emit-llvm -std=c++1y -O1 -o - %s         | FileCheck --check-prefix=GO1 %s
+// RUN: %clang_cc1 -triple i686-windows-msvc -fms-compatibility   -emit-llvm -std=c++1y -O0 -o - %s -DMSABI | FileCheck --check-prefix=MSC --check-prefix=M32 %s
+// RUN: %clang_cc1 -triple x86_64-windows-msvc -fms-compatibility -emit-llvm -std=c++1y -O0 -o - %s -DMSABI | FileCheck --check-prefix=MSC --check-prefix=M64 %s
+// RUN: %clang_cc1 -triple i686-windows-gnu                       -emit-llvm -std=c++1y -O0 -o - %s         | FileCheck --check-prefix=GNU --check-prefix=G32 %s
+// RUN: %clang_cc1 -triple x86_64-windows-gnu                     -emit-llvm -std=c++1y -O0 -o - %s         | FileCheck --check-prefix=GNU --check-prefix=G64 %s
+// RUN: %clang_cc1 -triple i686-windows-msvc -fms-compatibility   -emit-llvm -std=c++1y -O1 -o - %s -DMSABI | FileCheck --check-prefix=MO1 %s
+// RUN: %clang_cc1 -triple i686-windows-gnu                       -emit-llvm -std=c++1y -O1 -o - %s         | FileCheck --check-prefix=GO1 %s
 
 // Helper structs to make templates more expressive.
 struct ImplicitInst_Imported {};

diff --git a/test/CodeGenCXX/ms-integer-static-data-members-exported.cpp b/test/CodeGenCXX/ms-integer-static-data-members-exported.cpp
new file mode 100644 (file)
index 0000000..3f868f3
--- /dev/null
+++ b/test/CodeGenCXX/ms-integer-static-data-members-exported.cpp
@@ -0,0 +1,22 @@
+// RUN: %clang_cc1 -emit-llvm -triple=i386-pc-win32 -fms-compatibility %s -o - | FileCheck %s
+
+enum Enum { zero, one, two };
+
+struct __declspec(dllexport) S {
+  // In MS compatibility mode, this counts as a definition.
+  // Since it is exported, it must be emitted even if it's unreferenced.
+  static const short x = 42;
+
+  // This works for enums too.
+  static const Enum y = two;
+
+  struct NonExported {
+    // dllexport is not inherited by this nested class.
+    // Since z is not referenced, it should not be emitted.
+    static const int z = 42;
+  };
+};
+
+// CHECK: @"\01?x@S@@2FB" = weak_odr dllexport constant i16 42, align 2
+// CHECK: @"\01?y@S@@2W4Enum@@B" = weak_odr dllexport constant i32 2, align 4
+// CHECK-NOT: NonExported

diff --git a/test/CodeGenCXX/ms-integer-static-data-members.cpp b/test/CodeGenCXX/ms-integer-static-data-members.cpp
index 5505db1e9bbbb7eeb53c15b3743d866bcdf2b1f9..b02b679d71a137d6ab69964be9e605a929ef12da 100644 (file)
--- a/test/CodeGenCXX/ms-integer-static-data-members.cpp
+++ b/test/CodeGenCXX/ms-integer-static-data-members.cpp
@@ -1,7 +1,7 @@
-// RUN: %clang_cc1 -emit-llvm -triple=i386-pc-win32 %s -o - | FileCheck %s
-// RUN: %clang_cc1 -DINLINE_INIT -emit-llvm -triple=i386-pc-win32 %s -o - | FileCheck %s --check-prefix=CHECK-INLINE
-// RUN: %clang_cc1 -DREAL_DEFINITION -emit-llvm -triple=i386-pc-win32 %s -o - | FileCheck %s --check-prefix=CHECK-OUTOFLINE
-// RUN: %clang_cc1 -DINLINE_INIT -DREAL_DEFINITION -emit-llvm -triple=i386-pc-win32 %s -o - | FileCheck %s --check-prefix=CHECK-INLINE
+// RUN: %clang_cc1 -emit-llvm -triple=i386-pc-win32 -fms-compatibility %s -o - | FileCheck %s
+// RUN: %clang_cc1 -DINLINE_INIT -emit-llvm -triple=i386-pc-win32 -fms-compatibility %s -o - | FileCheck %s --check-prefix=CHECK-INLINE
+// RUN: %clang_cc1 -DREAL_DEFINITION -emit-llvm -triple=i386-pc-win32 -fms-compatibility %s -o - | FileCheck %s --check-prefix=CHECK-OUTOFLINE
+// RUN: %clang_cc1 -DINLINE_INIT -DREAL_DEFINITION -emit-llvm -triple=i386-pc-win32 -fms-compatibility %s -o - | FileCheck %s --check-prefix=CHECK-INLINE
 
 struct S {
   // For MS ABI, we emit a linkonce_odr definition here, even though it's really just a declaration.