[c++2a] Allow comparison functions to be explicitly defaulted.

This adds some initial syntactic checking that only the appropriate
function signatures can be defaulted. No implicit definitions are
generated yet.

1 files changed, 9 insertions, 14 deletions

diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index 80235d8496d..dae4af8bb24 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -3322,12 +3322,14 @@ bool FunctionDecl::doesDeclarationForceExternallyVisibleDefinition() const {
   return FoundBody;
 }
 
-SourceRange FunctionDecl::getReturnTypeSourceRange() const {
+FunctionTypeLoc FunctionDecl::getFunctionTypeLoc() const {
   const TypeSourceInfo *TSI = getTypeSourceInfo();
-  if (!TSI)
-    return SourceRange();
-  FunctionTypeLoc FTL =
-      TSI->getTypeLoc().IgnoreParens().getAs<FunctionTypeLoc>();
+  return TSI ? TSI->getTypeLoc().IgnoreParens().getAs<FunctionTypeLoc>()
+             : FunctionTypeLoc();
+}
+
+SourceRange FunctionDecl::getReturnTypeSourceRange() const {
+  FunctionTypeLoc FTL = getFunctionTypeLoc();
   if (!FTL)
     return SourceRange();
 
@@ -3343,15 +3345,8 @@ SourceRange FunctionDecl::getReturnTypeSourceRange() const {
 }
 
 SourceRange FunctionDecl::getExceptionSpecSourceRange() const {
-  const TypeSourceInfo *TSI = getTypeSourceInfo();
-  if (!TSI)
-    return SourceRange();
-  FunctionTypeLoc FTL =
-    TSI->getTypeLoc().IgnoreParens().getAs<FunctionTypeLoc>();
-  if (!FTL)
-    return SourceRange();
-
-  return FTL.getExceptionSpecRange();
+  FunctionTypeLoc FTL = getFunctionTypeLoc();
+  return FTL ? FTL.getExceptionSpecRange() : SourceRange();
 }
 
 /// For an inline function definition in C, or for a gnu_inline function