P0012R1: add Itanium ABI support for throwing non-noexcept function pointers and catching as noexcept.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@288305 91177308-0d34-0410-b5e6-96231b3b80d8

Author: zygoloid

Diff for: lib/CodeGen/ItaniumCXXABI.cpp

@@ -2474,7 +2474,13 @@ class ItaniumRTTIBuilder {
 
     /// PTI_ContainingClassIncomplete - Containing class is incomplete.
     /// (in pointer to member).
-    PTI_ContainingClassIncomplete = 0x10
+    PTI_ContainingClassIncomplete = 0x10,
+
+    /// PTI_TransactionSafe - Pointee is transaction_safe function (C++ TM TS).
+    //PTI_TransactionSafe = 0x20,
+
+    /// PTI_Noexcept - Pointee is noexcept function (C++1z).
+    PTI_Noexcept = 0x40,
   };
 
   // VMI type info flags.
@@ -3124,21 +3130,6 @@ llvm::Constant *ItaniumRTTIBuilder::BuildTypeInfo(QualType Ty, bool Force,
   return llvm::ConstantExpr::getBitCast(GV, CGM.Int8PtrTy);
 }
 
-/// ComputeQualifierFlags - Compute the pointer type info flags from the
-/// given qualifier.
-static unsigned ComputeQualifierFlags(Qualifiers Quals) {
-  unsigned Flags = 0;
-
-  if (Quals.hasConst())
-    Flags |= ItaniumRTTIBuilder::PTI_Const;
-  if (Quals.hasVolatile())
-    Flags |= ItaniumRTTIBuilder::PTI_Volatile;
-  if (Quals.hasRestrict())
-    Flags |= ItaniumRTTIBuilder::PTI_Restrict;
-
-  return Flags;
-}
-
 /// BuildObjCObjectTypeInfo - Build the appropriate kind of type_info
 /// for the given Objective-C object type.
 void ItaniumRTTIBuilder::BuildObjCObjectTypeInfo(const ObjCObjectType *OT) {
@@ -3322,23 +3313,44 @@ void ItaniumRTTIBuilder::BuildVMIClassTypeInfo(const CXXRecordDecl *RD) {
   }
 }
 
+/// Compute the flags for a __pbase_type_info, and remove the corresponding
+/// pieces from \p Type.
+static unsigned extractPBaseFlags(ASTContext &Ctx, QualType &Type) {
+  unsigned Flags = 0;
+
+  if (Type.isConstQualified())
+    Flags |= ItaniumRTTIBuilder::PTI_Const;
+  if (Type.isVolatileQualified())
+    Flags |= ItaniumRTTIBuilder::PTI_Volatile;
+  if (Type.isRestrictQualified())
+    Flags |= ItaniumRTTIBuilder::PTI_Restrict;
+  Type = Type.getUnqualifiedType();
+
+  // Itanium C++ ABI 2.9.5p7:
+  //   When the abi::__pbase_type_info is for a direct or indirect pointer to an
+  //   incomplete class type, the incomplete target type flag is set.
+  if (ContainsIncompleteClassType(Type))
+    Flags |= ItaniumRTTIBuilder::PTI_Incomplete;
+
+  if (auto *Proto = Type->getAs<FunctionProtoType>()) {
+    if (Proto->isNothrow(Ctx)) {
+      Flags |= ItaniumRTTIBuilder::PTI_Noexcept;
+      Type = Ctx.getFunctionType(
+          Proto->getReturnType(), Proto->getParamTypes(),
+          Proto->getExtProtoInfo().withExceptionSpec(EST_None));
+    }
+  }
+
+  return Flags;
+}
+
 /// BuildPointerTypeInfo - Build an abi::__pointer_type_info struct,
 /// used for pointer types.
 void ItaniumRTTIBuilder::BuildPointerTypeInfo(QualType PointeeTy) {
-  Qualifiers Quals;
-  QualType UnqualifiedPointeeTy =
-    CGM.getContext().getUnqualifiedArrayType(PointeeTy, Quals);
-
   // Itanium C++ ABI 2.9.5p7:
   //   __flags is a flag word describing the cv-qualification and other
   //   attributes of the type pointed to
-  unsigned Flags = ComputeQualifierFlags(Quals);
-
-  // Itanium C++ ABI 2.9.5p7:
-  //   When the abi::__pbase_type_info is for a direct or indirect pointer to an
-  //   incomplete class type, the incomplete target type flag is set.
-  if (ContainsIncompleteClassType(UnqualifiedPointeeTy))
-    Flags |= PTI_Incomplete;
+  unsigned Flags = extractPBaseFlags(CGM.getContext(), PointeeTy);
 
   llvm::Type *UnsignedIntLTy =
     CGM.getTypes().ConvertType(CGM.getContext().UnsignedIntTy);
@@ -3348,7 +3360,7 @@ void ItaniumRTTIBuilder::BuildPointerTypeInfo(QualType PointeeTy) {
   //  __pointee is a pointer to the std::type_info derivation for the
   //  unqualified type being pointed to.
   llvm::Constant *PointeeTypeInfo =
-    ItaniumRTTIBuilder(CXXABI).BuildTypeInfo(UnqualifiedPointeeTy);
+      ItaniumRTTIBuilder(CXXABI).BuildTypeInfo(PointeeTy);
   Fields.push_back(PointeeTypeInfo);
 }
 
@@ -3358,23 +3370,12 @@ void
 ItaniumRTTIBuilder::BuildPointerToMemberTypeInfo(const MemberPointerType *Ty) {
   QualType PointeeTy = Ty->getPointeeType();
 
-  Qualifiers Quals;
-  QualType UnqualifiedPointeeTy =
-    CGM.getContext().getUnqualifiedArrayType(PointeeTy, Quals);
-
   // Itanium C++ ABI 2.9.5p7:
   //   __flags is a flag word describing the cv-qualification and other
   //   attributes of the type pointed to.
-  unsigned Flags = ComputeQualifierFlags(Quals);
+  unsigned Flags = extractPBaseFlags(CGM.getContext(), PointeeTy);
 
   const RecordType *ClassType = cast<RecordType>(Ty->getClass());
-
-  // Itanium C++ ABI 2.9.5p7:
-  //   When the abi::__pbase_type_info is for a direct or indirect pointer to an
-  //   incomplete class type, the incomplete target type flag is set.
-  if (ContainsIncompleteClassType(UnqualifiedPointeeTy))
-    Flags |= PTI_Incomplete;
-
   if (IsIncompleteClassType(ClassType))
     Flags |= PTI_ContainingClassIncomplete;
 
@@ -3386,7 +3387,7 @@ ItaniumRTTIBuilder::BuildPointerToMemberTypeInfo(const MemberPointerType *Ty) {
   //   __pointee is a pointer to the std::type_info derivation for the
   //   unqualified type being pointed to.
   llvm::Constant *PointeeTypeInfo =
-    ItaniumRTTIBuilder(CXXABI).BuildTypeInfo(UnqualifiedPointeeTy);
+      ItaniumRTTIBuilder(CXXABI).BuildTypeInfo(PointeeTy);
   Fields.push_back(PointeeTypeInfo);
 
   // Itanium C++ ABI 2.9.5p9:

Diff for: test/CodeGenCXX/rtti-qualfn.cpp

@@ -0,0 +1,23 @@
+// RUN: %clang_cc1 -std=c++1z -I%S %s -triple x86_64-linux-gnu -emit-llvm -o - -fcxx-exceptions | FileCheck %s
+
+#include "typeinfo"
+
+struct A {};
+
+// CHECK-DAG: @_ZTIFvvE = linkonce_odr constant { i8*, i8* } { i8* bitcast (i8** getelementptr inbounds (i8*, i8** @_ZTVN10__cxxabiv120__function_type_infoE, i64 2) to i8*), i8* getelementptr inbounds ([5 x i8], [5 x i8]* @_ZTSFvvE, i32 0, i32 0) }, comdat
+// CHECK-DAG: @_ZTIPDoFvvE = linkonce_odr constant { i8*, i8*, i32, i8* } { i8* bitcast (i8** getelementptr inbounds (i8*, i8** @_ZTVN10__cxxabiv119__pointer_type_infoE, i64 2) to i8*), i8* getelementptr inbounds ([8 x i8], [8 x i8]* @_ZTSPDoFvvE, i32 0, i32 0), i32 64, i8* bitcast ({ i8*, i8* }* @_ZTIFvvE to i8*) }, comdat
+auto &ti_noexcept_ptr = typeid(void (A::*)() noexcept);
+// CHECK-DAG: @_ZTIM1ADoFvvE = linkonce_odr constant { i8*, i8*, i32, i8*, i8* } { i8* bitcast (i8** getelementptr inbounds (i8*, i8** @_ZTVN10__cxxabiv129__pointer_to_member_type_infoE, i64 2) to i8*), i8* getelementptr inbounds ([10 x i8], [10 x i8]* @_ZTSM1ADoFvvE, i32 0, i32 0), i32 64, i8* bitcast ({ i8*, i8* }* @_ZTIFvvE to i8*), i8* bitcast ({ i8*, i8* }* @_ZTI1A to i8*) }, comdat
+auto &ti_noexcept_memptr = typeid(void (A::*)() noexcept);
+
+// CHECK-LABEL: define void @_Z1fv(
+__attribute__((noreturn)) void f() noexcept {
+  // CHECK: call void @__cxa_throw({{.*}}@_ZTIPDoFvvE
+  throw f;
+}
+
+// CHECK-LABEL: define void @_Z1gM1ADoFvvE(
+void g(__attribute__((noreturn)) void (A::*p)() noexcept) {
+  // CHECK: call void @__cxa_throw({{.*}}@_ZTIM1ADoFvvE
+  throw p;
+}

Diff for: www/cxx_status.html

@@ -612,9 +612,7 @@ <h2 id="cxx17">C++1z implementation status</h2>
     <tr>
       <td>Make exception specifications part of the type system</td>
       <td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0012r1.html">P0012R1</a></td>
-      <td class="partial" align="center">Partial</td>
-      <!-- We don't correctly support throwing noexcept function types and
-           catching as non-noexcept yet. -->
+      <td class="svn" align="center">SVN</td>
     </tr>
     <tr>
       <td><tt>__has_include</tt> in preprocessor conditionals</td>