From 99677afd54fba7deb6a5c8c2de52d46cbb344316 Mon Sep 17 00:00:00 2001
From: Richard Smith <richard-llvm@metafoo.co.uk>
Date: Tue, 18 Oct 2016 06:47:03 +0000
Subject: [PATCH] [c++1z] Use canonical expression equivalence to determine
 whether two different dependent noexcept specifications result in the same
 canonical function type.

We still use non-canonical hashing when deduplicating type sugar so that
diagnostics will point to the right place.

llvm-svn: 284457
---
 clang/include/clang/AST/Type.h                     |  3 ++-
 clang/lib/AST/ASTContext.cpp                       | 22 +++++++++++-----------
 clang/lib/AST/Type.cpp                             |  6 +++---
 .../test/SemaCXX/cxx1z-noexcept-function-type.cpp  | 13 +++++++++++++
 4 files changed, 29 insertions(+), 15 deletions(-)
 create mode 100644 clang/test/SemaCXX/cxx1z-noexcept-function-type.cpp

diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index e9351a9..691a7dc 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -3473,7 +3473,8 @@ public:
   void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Ctx);
   static void Profile(llvm::FoldingSetNodeID &ID, QualType Result,
                       param_type_iterator ArgTys, unsigned NumArgs,
-                      const ExtProtoInfo &EPI, const ASTContext &Context);
+                      const ExtProtoInfo &EPI, const ASTContext &Context,
+                      bool Canonical);
 };
 
 /// \brief Represents the dependent type named by a dependently-scoped
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 3da1c74..d2f01c0 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -3170,17 +3170,6 @@ ASTContext::getFunctionType(QualType ResultTy, ArrayRef<QualType> ArgArray,
                             const FunctionProtoType::ExtProtoInfo &EPI) const {
   size_t NumArgs = ArgArray.size();
 
-  // Unique functions, to guarantee there is only one function of a particular
-  // structure.
-  llvm::FoldingSetNodeID ID;
-  FunctionProtoType::Profile(ID, ResultTy, ArgArray.begin(), NumArgs, EPI,
-                             *this);
-
-  void *InsertPos = nullptr;
-  if (FunctionProtoType *FTP =
-        FunctionProtoTypes.FindNodeOrInsertPos(ID, InsertPos))
-    return QualType(FTP, 0);
-
   bool NoexceptInType = getLangOpts().CPlusPlus1z;
 
   bool IsCanonicalExceptionSpec =
@@ -3193,6 +3182,17 @@ ASTContext::getFunctionType(QualType ResultTy, ArrayRef<QualType> ArgArray,
     if (!ArgArray[i].isCanonicalAsParam())
       isCanonical = false;
 
+  // Unique functions, to guarantee there is only one function of a particular
+  // structure.
+  llvm::FoldingSetNodeID ID;
+  FunctionProtoType::Profile(ID, ResultTy, ArgArray.begin(), NumArgs, EPI,
+                             *this, isCanonical);
+
+  void *InsertPos = nullptr;
+  if (FunctionProtoType *FTP =
+        FunctionProtoTypes.FindNodeOrInsertPos(ID, InsertPos))
+    return QualType(FTP, 0);
+
   // If this type isn't canonical, get the canonical version of it.
   // The exception spec is not part of the canonical type.
   QualType Canonical;
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index 2601fa4..3e776e3 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -2850,7 +2850,7 @@ bool FunctionProtoType::isTemplateVariadic() const {
 void FunctionProtoType::Profile(llvm::FoldingSetNodeID &ID, QualType Result,
                                 const QualType *ArgTys, unsigned NumParams,
                                 const ExtProtoInfo &epi,
-                                const ASTContext &Context) {
+                                const ASTContext &Context, bool Canonical) {
 
   // We have to be careful not to get ambiguous profile encodings.
   // Note that valid type pointers are never ambiguous with anything else.
@@ -2889,7 +2889,7 @@ void FunctionProtoType::Profile(llvm::FoldingSetNodeID &ID, QualType Result,
       ID.AddPointer(Ex.getAsOpaquePtr());
   } else if (epi.ExceptionSpec.Type == EST_ComputedNoexcept &&
              epi.ExceptionSpec.NoexceptExpr) {
-    epi.ExceptionSpec.NoexceptExpr->Profile(ID, Context, false);
+    epi.ExceptionSpec.NoexceptExpr->Profile(ID, Context, Canonical);
   } else if (epi.ExceptionSpec.Type == EST_Uninstantiated ||
              epi.ExceptionSpec.Type == EST_Unevaluated) {
     ID.AddPointer(epi.ExceptionSpec.SourceDecl->getCanonicalDecl());
@@ -2905,7 +2905,7 @@ void FunctionProtoType::Profile(llvm::FoldingSetNodeID &ID, QualType Result,
 void FunctionProtoType::Profile(llvm::FoldingSetNodeID &ID,
                                 const ASTContext &Ctx) {
   Profile(ID, getReturnType(), param_type_begin(), NumParams, getExtProtoInfo(),
-          Ctx);
+          Ctx, isCanonicalUnqualified());
 }
 
 QualType TypedefType::desugar() const {
diff --git a/clang/test/SemaCXX/cxx1z-noexcept-function-type.cpp b/clang/test/SemaCXX/cxx1z-noexcept-function-type.cpp
new file mode 100644
index 0000000..e2a947e
--- /dev/null
+++ b/clang/test/SemaCXX/cxx1z-noexcept-function-type.cpp
@@ -0,0 +1,13 @@
+// RUN: %clang_cc1 -std=c++1z -verify %s
+
+template<typename T> void redecl1() noexcept(noexcept(T())) {} // expected-note {{previous}}
+template<typename T> void redecl1() noexcept(noexcept(T())); // ok, same type
+template<typename T> void redecl1() noexcept(noexcept(T())) {} // expected-error {{redefinition}}
+
+template<bool A, bool B> void redecl2() noexcept(A); // expected-note {{previous}}
+template<bool A, bool B> void redecl2() noexcept(B); // expected-error {{conflicting types}}
+
+// These have the same canonical type.
+// FIXME: It's not clear whether this is supposed to be valid.
+template<typename A, typename B> void redecl3() throw(A);
+template<typename A, typename B> void redecl3() throw(B);
-- 
2.7.4