PR 12586: Fix assert while running libc++ testsuite: deal with exception

specifications on member function templates of class templates and other such
nested beasties. Store the function template from which we are to instantiate
an exception specification rather than trying to deduce it. Plus some
additional test cases.

llvm-svn: 155076

7 files changed, 110 insertions, 30 deletions

diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index 9fd49016729..7b615c19dcc 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -2701,7 +2701,8 @@ public:
     ExtProtoInfo() :
       Variadic(false), HasTrailingReturn(false), TypeQuals(0),
       ExceptionSpecType(EST_None), RefQualifier(RQ_None),
-      NumExceptions(0), Exceptions(0), NoexceptExpr(0), ExceptionSpecDecl(0),
+      NumExceptions(0), Exceptions(0), NoexceptExpr(0),
+      ExceptionSpecDecl(0), ExceptionSpecTemplate(0),
       ConsumedArguments(0) {}
 
     FunctionType::ExtInfo ExtInfo;
@@ -2714,6 +2715,7 @@ public:
     const QualType *Exceptions;
     Expr *NoexceptExpr;
     FunctionDecl *ExceptionSpecDecl;
+    FunctionDecl *ExceptionSpecTemplate;
     const bool *ConsumedArguments;
   };
 
@@ -2759,9 +2761,10 @@ private:
   // NoexceptExpr - Instead of Exceptions, there may be a single Expr* pointing
   // to the expression in the noexcept() specifier.
 
-  // ExceptionSpecDecl - Instead of Exceptions, there may be a single
-  // FunctionDecl* pointing to the function which should be used to resolve
-  // this function type's exception specification.
+  // ExceptionSpecDecl, ExceptionSpecTemplate - Instead of Exceptions, there may
+  // be a pair of FunctionDecl* pointing to the function which should be used to
+  // instantiate this function type's exception specification, and the function
+  // from which it should be instantiated.
 
   // ConsumedArgs - A variable size array, following Exceptions
   // and of length NumArgs, holding flags indicating which arguments
@@ -2804,6 +2807,7 @@ public:
       EPI.NoexceptExpr = getNoexceptExpr();
     } else if (EPI.ExceptionSpecType == EST_Uninstantiated) {
       EPI.ExceptionSpecDecl = getExceptionSpecDecl();
+      EPI.ExceptionSpecTemplate = getExceptionSpecTemplate();
     }
     if (hasAnyConsumedArgs())
       EPI.ConsumedArguments = getConsumedArgsBuffer();
@@ -2847,10 +2851,22 @@ public:
     // NoexceptExpr sits where the arguments end.
     return *reinterpret_cast<Expr *const *>(arg_type_end());
   }
+  /// \brief If this function type has an uninstantiated exception
+  /// specification, this is the function whose exception specification
+  /// is represented by this type.
   FunctionDecl *getExceptionSpecDecl() const {
     if (getExceptionSpecType() != EST_Uninstantiated)
       return 0;
-    return *reinterpret_cast<FunctionDecl * const *>(arg_type_end());
+    return reinterpret_cast<FunctionDecl * const *>(arg_type_end())[0];
+  }
+  /// \brief If this function type has an uninstantiated exception
+  /// specification, this is the function whose exception specification
+  /// should be instantiated to find the exception specification for
+  /// this type.
+  FunctionDecl *getExceptionSpecTemplate() const {
+    if (getExceptionSpecType() != EST_Uninstantiated)
+      return 0;
+    return reinterpret_cast<FunctionDecl * const *>(arg_type_end())[1];
   }
   bool isNothrow(ASTContext &Ctx) const {
     ExceptionSpecificationType EST = getExceptionSpecType();
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 65ddc059fa7..cb4d336de15 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -2195,7 +2195,7 @@ ASTContext::getFunctionType(QualType ResultTy,
   else if (EPI.ExceptionSpecType == EST_ComputedNoexcept) {
     Size += sizeof(Expr*);
   } else if (EPI.ExceptionSpecType == EST_Uninstantiated) {
-    Size += sizeof(FunctionDecl*);
+    Size += 2 * sizeof(FunctionDecl*);
   }
   if (EPI.ConsumedArguments)
     Size += NumArgs * sizeof(bool);
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index 10c1adc875d..3f6a09457d1 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -1550,7 +1550,8 @@ FunctionProtoType::FunctionProtoType(QualType result, const QualType *args,
     // Store the function decl from which we will resolve our
     // exception specification.
     FunctionDecl **slot = reinterpret_cast<FunctionDecl**>(argSlot + numArgs);
-    *slot = epi.ExceptionSpecDecl;
+    slot[0] = epi.ExceptionSpecDecl;
+    slot[1] = epi.ExceptionSpecTemplate;
     // This exception specification doesn't make the type dependent, because
     // it's not instantiated as part of instantiating the type.
   }
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 669ba3ad376..d2e0e6b63b4 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -9776,9 +9776,8 @@ void Sema::MarkFunctionReferenced(SourceLocation Loc, FunctionDecl *Func) {
 
   // Instantiate the exception specification for any function which is
   // used: CodeGen will need it.
-  if (Func->getTemplateInstantiationPattern() &&
-      Func->getType()->castAs<FunctionProtoType>()->getExceptionSpecType()
-        == EST_Uninstantiated)
+  const FunctionProtoType *FPT = Func->getType()->getAs<FunctionProtoType>();
+  if (FPT && FPT->getExceptionSpecType() == EST_Uninstantiated)
     InstantiateExceptionSpec(Loc, Func);
 
   // Implicit instantiation of function templates and member functions of
diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 4d312f855f5..c7bd99c1ca6 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -2251,6 +2251,8 @@ static void addInstantiatedParametersToScope(Sema &S, FunctionDecl *Function,
 static void InstantiateExceptionSpec(Sema &SemaRef, FunctionDecl *New,
                                      const FunctionProtoType *Proto,
                            const MultiLevelTemplateArgumentList &TemplateArgs) {
+  assert(Proto->getExceptionSpecType() != EST_Uninstantiated);
+
   // C++11 [expr.prim.general]p3:
   //   If a declaration declares a member function or member function 
   //   template of a class X, the expression this is a prvalue of type 
@@ -2377,20 +2379,8 @@ static void InstantiateExceptionSpec(Sema &SemaRef, FunctionDecl *New,
 
 void Sema::InstantiateExceptionSpec(SourceLocation PointOfInstantiation,
                                     FunctionDecl *Decl) {
-  // Find the template declaration which contains the exception specification.
-  // Per [except.spec]p4, prefer the exception spec on the primary template
-  // if this is an explicit instantiation.
-  FunctionDecl *Tmpl = 0;
-  if (Decl->getPrimaryTemplate())
-    Tmpl = Decl->getPrimaryTemplate()->getTemplatedDecl();
-  else if (FunctionDecl *MemTmpl = Decl->getInstantiatedFromMemberFunction())
-    Tmpl = MemTmpl;
-  else
-    Tmpl = Decl->getTemplateInstantiationPattern();
-  assert(Tmpl && "can't instantiate non-template");
-
-  if (Decl->getType()->castAs<FunctionProtoType>()->getExceptionSpecType()
-        != EST_Uninstantiated)
+  const FunctionProtoType *Proto = Decl->getType()->castAs<FunctionProtoType>();
+  if (Proto->getExceptionSpecType() != EST_Uninstantiated)
     return;
 
   InstantiatingTemplate Inst(*this, PointOfInstantiation, Decl,
@@ -2406,10 +2396,12 @@ void Sema::InstantiateExceptionSpec(SourceLocation PointOfInstantiation,
   MultiLevelTemplateArgumentList TemplateArgs =
     getTemplateInstantiationArgs(Decl, 0, /*RelativeToPrimary*/true);
 
-  addInstantiatedParametersToScope(*this, Decl, Tmpl, Scope, TemplateArgs);
+  FunctionDecl *Template = Proto->getExceptionSpecTemplate();
+  addInstantiatedParametersToScope(*this, Decl, Template, Scope, TemplateArgs);
 
-  const FunctionProtoType *Proto = Tmpl->getType()->castAs<FunctionProtoType>();
-  ::InstantiateExceptionSpec(*this, Decl, Proto, TemplateArgs);
+  ::InstantiateExceptionSpec(*this, Decl,
+                             Template->getType()->castAs<FunctionProtoType>(),
+                             TemplateArgs);
 }
 
 /// \brief Initializes the common fields of an instantiation function
@@ -2457,6 +2449,10 @@ TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New,
         EPI.ExceptionSpecType != EST_None &&
         EPI.ExceptionSpecType != EST_DynamicNone &&
         EPI.ExceptionSpecType != EST_BasicNoexcept) {
+      FunctionDecl *ExceptionSpecTemplate = Tmpl;
+      if (EPI.ExceptionSpecType == EST_Uninstantiated)
+        ExceptionSpecTemplate = EPI.ExceptionSpecTemplate;
+
       // Mark the function has having an uninstantiated exception specification.
       const FunctionProtoType *NewProto
         = New->getType()->getAs<FunctionProtoType>();
@@ -2464,6 +2460,7 @@ TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New,
       EPI = NewProto->getExtProtoInfo();
       EPI.ExceptionSpecType = EST_Uninstantiated;
       EPI.ExceptionSpecDecl = New;
+      EPI.ExceptionSpecTemplate = ExceptionSpecTemplate;
       New->setType(SemaRef.Context.getFunctionType(NewProto->getResultType(),
                                                    NewProto->arg_type_begin(),
                                                    NewProto->getNumArgs(),
diff --git a/clang/test/CodeGenCXX/cxx11-exception-spec.cpp b/clang/test/CodeGenCXX/cxx11-exception-spec.cpp
index 4e08dce2ae7..194b80cdd47 100644
--- a/clang/test/CodeGenCXX/cxx11-exception-spec.cpp
+++ b/clang/test/CodeGenCXX/cxx11-exception-spec.cpp
@@ -3,9 +3,11 @@
 void h();
 
 template<typename T> void f() noexcept(sizeof(T) == 4) { h(); }
+template<typename T> void g() noexcept(sizeof(T) == 4);
 
 template<typename T> struct S {
   static void f() noexcept(sizeof(T) == 4) { h(); }
+  static void g() noexcept(sizeof(T) == 4);
 };
 
 // CHECK: define {{.*}} @_Z1fIsEvv() {
@@ -30,7 +32,7 @@ template void S<char16_t>::f();
 // CHECK: define {{.*}} @_ZN1SIA2_DsE1fEv() nounwind
 template void S<char16_t[2]>::f();
 
-void g() {
+void h() {
   // CHECK: define {{.*}} @_Z1fIiEvv() nounwind {
   f<int>();
   // CHECK: define {{.*}} @_Z1fIA2_iEvv() {
@@ -64,3 +66,55 @@ void g() {
   // CHECK-NOT: nounwind
   (void)&S<char>::f;
 }
+
+// CHECK: define {{.*}} @_Z1iv
+void i() {
+  // CHECK: declare {{.*}} @_Z1gIiEvv() nounwind
+  g<int>();
+  // CHECK: declare {{.*}} @_Z1gIA2_iEvv()
+  // CHECK-NOT: nounwind
+  g<int[2]>();
+
+  // CHECK: declare {{.*}} @_ZN1SIiE1gEv() nounwind
+  S<int>::g();
+  // CHECK: declare {{.*}} @_ZN1SIA2_iE1gEv()
+  // CHECK-NOT: nounwind
+  S<int[2]>::g();
+
+  // CHECK: declare {{.*}} @_Z1gIfEvv() nounwind
+  void (*g1)() = &g<float>;
+  // CHECK: declare {{.*}} @_Z1gIdEvv()
+  // CHECK-NOT: nounwind
+  void (*g2)() = &g<double>;
+
+  // CHECK: declare {{.*}} @_ZN1SIfE1gEv() nounwind
+  void (*g3)() = &S<float>::g;
+  // CHECK: declare {{.*}} @_ZN1SIdE1gEv()
+  // CHECK-NOT: nounwind
+  void (*g4)() = &S<double>::g;
+
+  // CHECK: declare {{.*}} @_Z1gIA4_cEvv() nounwind
+  (void)&g<char[4]>;
+  // CHECK: declare {{.*}} @_Z1gIcEvv()
+  // CHECK-NOT: nounwind
+  (void)&g<char>;
+
+  // CHECK: declare {{.*}} @_ZN1SIA4_cE1gEv() nounwind
+  (void)&S<char[4]>::g;
+  // CHECK: declare {{.*}} @_ZN1SIcE1gEv()
+  // CHECK-NOT: nounwind
+  (void)&S<char>::g;
+}
+
+template<typename T> struct Nested {
+  template<bool b, typename U> void f() noexcept(sizeof(T) == sizeof(U));
+};
+
+// CHECK: define {{.*}} @_Z1jv
+void j() {
+  // CHECK: declare {{.*}} @_ZN6NestedIiE1fILb1EcEEvv(
+  // CHECK-NOT: nounwind
+  Nested<int>().f<true, char>();
+  // CHECK: declare {{.*}} @_ZN6NestedIlE1fILb0ElEEvv({{.*}}) nounwind
+  Nested<long>().f<false, long>();
+}
diff --git a/clang/test/SemaTemplate/instantiate-exception-spec-cxx11.cpp b/clang/test/SemaTemplate/instantiate-exception-spec-cxx11.cpp
index d29c8862b9a..8a6f9efa68e 100644
--- a/clang/test/SemaTemplate/instantiate-exception-spec-cxx11.cpp
+++ b/clang/test/SemaTemplate/instantiate-exception-spec-cxx11.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 -ftemplate-depth 16 %s
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 -ftemplate-depth 16 -fcxx-exceptions -fexceptions %s
 
 // DR1330: an exception specification for a function template is only
 // instantiated when it is needed.
@@ -31,7 +31,7 @@ decltype(S<0>::recurse()) *pVoid1 = 0; // ok, exception spec not needed
 decltype(&S<0>::recurse) pFn = 0; // ok, exception spec not needed
 
 template<> struct S<10> {};
-void (*pFn2)() noexcept = &S<0>::recurse; // expected-note {{instantiation of exception spec}}
+void (*pFn2)() noexcept = &S<0>::recurse; // expected-note {{instantiation of exception spec}} expected-error {{not superset}}
 
 
 template<typename T> T go(T a) noexcept(noexcept(go(a))); // \
@@ -118,3 +118,16 @@ namespace pr9485 {
     f2(0); // expected-error {{ambiguous}}
   }
 }
+
+struct Exc1 { char c[4]; };
+struct Exc2 { double x, y, z; };
+struct Base {
+  virtual void f() noexcept; // expected-note {{overridden}}
+};
+template<typename T> struct Derived : Base {
+  void f() noexcept (sizeof(T) == 4); // expected-error {{is more lax}}
+  void g() noexcept (T::error);
+};
+
+Derived<Exc1> d1; // ok
+Derived<Exc2> d2; // expected-note {{in instantiation of}}