MS ABI: Don't use the Itanium scheme for numbering lambdas

The Itanium ABI will give out the same mangling number for two different
lambdas if their call operators have different types.  The MS ABI cannot
do the same because it does not mangle the return type into it's
lambdas.

This fixes PR20719.

llvm-svn: 216259

6 files changed, 85 insertions, 56 deletions

diff --git a/clang/include/clang/AST/MangleNumberingContext.h b/clang/include/clang/AST/MangleNumberingContext.h
index 56aec73f245..7a818557fdb 100644
--- a/clang/include/clang/AST/MangleNumberingContext.h
+++ b/clang/include/clang/AST/MangleNumberingContext.h
@@ -30,23 +30,20 @@ class VarDecl;
 
 /// \brief Keeps track of the mangled names of lambda expressions and block
 /// literals within a particular context.
-class MangleNumberingContext 
-    : public RefCountedBase<MangleNumberingContext> {
-  llvm::DenseMap<const Type *, unsigned> ManglingNumbers;
-
+class MangleNumberingContext : public RefCountedBase<MangleNumberingContext> {
 public:
   virtual ~MangleNumberingContext() {}
 
   /// \brief Retrieve the mangling number of a new lambda expression with the
   /// given call operator within this context.
-  unsigned getManglingNumber(const CXXMethodDecl *CallOperator);
+  virtual unsigned getManglingNumber(const CXXMethodDecl *CallOperator) = 0;
 
   /// \brief Retrieve the mangling number of a new block literal within this
   /// context.
-  unsigned getManglingNumber(const BlockDecl *BD);
+  virtual unsigned getManglingNumber(const BlockDecl *BD) = 0;
 
   /// Static locals are numbered by source order.
-  unsigned getStaticLocalNumber(const VarDecl *VD);
+  virtual unsigned getStaticLocalNumber(const VarDecl *VD) = 0;
 
   /// \brief Retrieve the mangling number of a static local variable within
   /// this context.
@@ -58,6 +55,6 @@ public:
   virtual unsigned getManglingNumber(const TagDecl *TD,
                                      unsigned MSLocalManglingNumber) = 0;
 };
-  
+
 } // end namespace clang
 #endif
diff --git a/clang/lib/AST/CMakeLists.txt b/clang/lib/AST/CMakeLists.txt
index 9006be64f73..6ce347b4a31 100644
--- a/clang/lib/AST/CMakeLists.txt
+++ b/clang/lib/AST/CMakeLists.txt
@@ -35,7 +35,6 @@ add_clang_library(clangAST
   ItaniumCXXABI.cpp
   ItaniumMangle.cpp
   Mangle.cpp
-  MangleNumberingContext.cpp
   MicrosoftCXXABI.cpp
   MicrosoftMangle.cpp
   NestedNameSpecifier.cpp
diff --git a/clang/lib/AST/ItaniumCXXABI.cpp b/clang/lib/AST/ItaniumCXXABI.cpp
index b5f8c0f4bc8..03428bfa79b 100644
--- a/clang/lib/AST/ItaniumCXXABI.cpp
+++ b/clang/lib/AST/ItaniumCXXABI.cpp
@@ -32,10 +32,32 @@ namespace {
 /// \brief Keeps track of the mangled names of lambda expressions and block
 /// literals within a particular context.
 class ItaniumNumberingContext : public MangleNumberingContext {
-  llvm::DenseMap<IdentifierInfo*, unsigned> VarManglingNumbers;
-  llvm::DenseMap<IdentifierInfo*, unsigned> TagManglingNumbers;
+  llvm::DenseMap<const Type *, unsigned> ManglingNumbers;
+  llvm::DenseMap<IdentifierInfo *, unsigned> VarManglingNumbers;
+  llvm::DenseMap<IdentifierInfo *, unsigned> TagManglingNumbers;
 
 public:
+  unsigned getManglingNumber(const CXXMethodDecl *CallOperator) override {
+    const FunctionProtoType *Proto =
+        CallOperator->getType()->getAs<FunctionProtoType>();
+    ASTContext &Context = CallOperator->getASTContext();
+
+    QualType Key =
+        Context.getFunctionType(Context.VoidTy, Proto->getParamTypes(),
+                                FunctionProtoType::ExtProtoInfo());
+    Key = Context.getCanonicalType(Key);
+    return ++ManglingNumbers[Key->castAs<FunctionProtoType>()];
+  }
+
+  unsigned getManglingNumber(const BlockDecl *BD) {
+    const Type *Ty = nullptr;
+    return ++ManglingNumbers[Ty];
+  }
+
+  unsigned getStaticLocalNumber(const VarDecl *VD) override {
+    return 0;
+  }
+
   /// Variable decls are numbered by identifier.
   unsigned getManglingNumber(const VarDecl *VD, unsigned) override {
     return ++VarManglingNumbers[VD->getIdentifier()];
diff --git a/clang/lib/AST/MangleNumberingContext.cpp b/clang/lib/AST/MangleNumberingContext.cpp
deleted file mode 100644
index 5f40f0347d0..00000000000
--- a/clang/lib/AST/MangleNumberingContext.cpp
+++ /dev/null
@@ -1,45 +0,0 @@
-//===--- MangleNumberingContext.cpp - Context for mangling numbers --------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-//  This file defines the LambdaMangleContext class, which keeps track of
-//  the Itanium C++ ABI mangling numbers for lambda expressions.
-//
-//===----------------------------------------------------------------------===//
-
-#include "clang/AST/MangleNumberingContext.h"
-#include "clang/AST/ASTContext.h"
-#include "clang/AST/DeclCXX.h"
-
-using namespace clang;
-
-unsigned
-MangleNumberingContext::getManglingNumber(const CXXMethodDecl *CallOperator) {
-  const FunctionProtoType *Proto
-    = CallOperator->getType()->getAs<FunctionProtoType>();
-  ASTContext &Context = CallOperator->getASTContext();
-
-  QualType Key = Context.getFunctionType(Context.VoidTy, Proto->getParamTypes(),
-                                         FunctionProtoType::ExtProtoInfo());
-  Key = Context.getCanonicalType(Key);
-  return ++ManglingNumbers[Key->castAs<FunctionProtoType>()];
-}
-
-unsigned
-MangleNumberingContext::getManglingNumber(const BlockDecl *BD) {
-  // FIXME: Compute a BlockPointerType?  Not obvious how.
-  const Type *Ty = nullptr;
-  return ++ManglingNumbers[Ty];
-}
-
-unsigned
-MangleNumberingContext::getStaticLocalNumber(const VarDecl *VD) {
-  // FIXME: Compute a BlockPointerType?  Not obvious how.
-  const Type *Ty = nullptr;
-  return ++ManglingNumbers[Ty];
-}
diff --git a/clang/lib/AST/MicrosoftCXXABI.cpp b/clang/lib/AST/MicrosoftCXXABI.cpp
index 6870315b216..64b3c1f152e 100644
--- a/clang/lib/AST/MicrosoftCXXABI.cpp
+++ b/clang/lib/AST/MicrosoftCXXABI.cpp
@@ -28,7 +28,28 @@ namespace {
 /// \brief Numbers things which need to correspond across multiple TUs.
 /// Typically these are things like static locals, lambdas, or blocks.
 class MicrosoftNumberingContext : public MangleNumberingContext {
+  llvm::DenseMap<const Type *, unsigned> ManglingNumbers;
+  unsigned LambdaManglingNumber;
+  unsigned StaticLocalNumber;
+
 public:
+  MicrosoftNumberingContext()
+      : MangleNumberingContext(), LambdaManglingNumber(0),
+        StaticLocalNumber(0) {}
+
+  unsigned getManglingNumber(const CXXMethodDecl *CallOperator) override {
+    return ++LambdaManglingNumber;
+  }
+
+  unsigned getManglingNumber(const BlockDecl *BD) {
+    const Type *Ty = nullptr;
+    return ++ManglingNumbers[Ty];
+  }
+
+  unsigned getStaticLocalNumber(const VarDecl *VD) override {
+    return ++StaticLocalNumber;
+  }
+
   unsigned getManglingNumber(const VarDecl *VD,
                              unsigned MSLocalManglingNumber) override {
     return MSLocalManglingNumber;
diff --git a/clang/test/CodeGenCXX/pr20719.cpp b/clang/test/CodeGenCXX/pr20719.cpp
new file mode 100644
index 00000000000..208d1113584
--- /dev/null
+++ b/clang/test/CodeGenCXX/pr20719.cpp
@@ -0,0 +1,35 @@
+// RUN: %clang_cc1 -triple i686-windows-msvc -emit-llvm -std=c++11 -o - %s | FileCheck %s
+
+// Make sure that we emit H's constructor twice: once with the first lambda
+// inside of 'lep' and again with the second lambda inside of 'lep'.
+// CHECK-DAG: @"\01??0?$H@V<lambda_1>@??$lep@X@@YAXXZ@@@QAE@XZ"
+// CHECK-DAG: @"\01??0?$H@V<lambda_2>@??$lep@X@@YAXXZ@@@QAE@XZ"
+
+template <typename>
+struct H {
+  H() {}
+};
+
+template <typename Fx>
+int K_void(const Fx &) {
+  H<Fx> callee;
+  return 0;
+}
+template <typename Fx>
+int K_int(const Fx &) {
+  H<Fx> callee;
+  return 0;
+}
+
+struct pair {
+  pair(int, int);
+};
+
+struct E1;
+
+template <typename>
+void lep() {
+  pair x(K_void([] {}), K_int([] {}));
+}
+
+auto z = lep<void>;