Diagnose function template definitions inside functions

The parser can only be tricked into parsing a function template
definition by inserting a typename keyword before the function template
declaration. This used to make us crash, and now it's fixed.

While here, remove an unneeded boolean parameter from ParseDeclGroup.
This boolean always corresponded to non-typedef declarators at file
scope. ParseDeclGroup already has precise diagnostics for the function
definition typedef case, so we can let that through.

Fixes PR21839.

llvm-svn: 224287

1 files changed, 5 insertions, 3 deletions

diff --git a/clang/lib/Parse/ParseDecl.cpp b/clang/lib/Parse/ParseDecl.cpp
index 03e827e69c0..0b84f2fbbd5 100644
--- a/clang/lib/Parse/ParseDecl.cpp
+++ b/clang/lib/Parse/ParseDecl.cpp
@@ -1466,7 +1466,7 @@ Parser::ParseSimpleDeclaration(unsigned Context,
   }
 
   DS.takeAttributesFrom(Attrs);
-  return ParseDeclGroup(DS, Context, /*FunctionDefs=*/ false, &DeclEnd, FRI);
+  return ParseDeclGroup(DS, Context, &DeclEnd, FRI);
 }
 
 /// Returns true if this might be the start of a declarator, or a common typo
@@ -1621,7 +1621,6 @@ void Parser::SkipMalformedDecl() {
 /// result.
 Parser::DeclGroupPtrTy Parser::ParseDeclGroup(ParsingDeclSpec &DS,
                                               unsigned Context,
-                                              bool AllowFunctionDefinitions,
                                               SourceLocation *DeclEnd,
                                               ForRangeInit *FRI) {
   // Parse the first declarator.
@@ -1669,7 +1668,10 @@ Parser::DeclGroupPtrTy Parser::ParseDeclGroup(ParsingDeclSpec &DS,
       // start of a function definition in GCC-extended K&R C.
       !isDeclarationAfterDeclarator()) {
 
-    if (AllowFunctionDefinitions) {
+    // Function definitions are only allowed at file scope and in C++ classes.
+    // The C++ inline method definition case is handled elsewhere, so we only
+    // need to handle the file scope definition case.
+    if (Context == Declarator::FileContext) {
       if (isStartOfFunctionDefinition(D)) {
         if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef) {
           Diag(Tok, diag::err_function_declared_typedef);