[cfe-dev] Patch to correct compilation errors related to class friend declarations

[Douglas Gregor]

On Nov 4, 2011, at 8:34 PM, Tom Honermann wrote:

> I checked out cfe/trunk today and attempted a build using an older gcc compiler (4.0.3) on Linux.  The build failed in a few places with the errors below.  The attached patch corrects these.  Each of the errors was related to class friend declarations.
> 
> llvm-trunk/tools/clang/include/clang/Basic/Diagnostic.h:590: error: 'clang::DiagnosticsEngine::<anonymous enum> clang::DiagnosticsEngine::MaxArguments' is private
> llvm-trunk/tools/clang/include/clang/Basic/PartialDiagnostic.h:36: error: within this context
> llvm-trunk/tools/clang/include/clang/Basic/Diagnostic.h:621: error: 'clang::DiagnosticsEngine::<anonymous enum> clang::DiagnosticsEngine::MaxFixItHints' is private
> llvm-trunk/tools/clang/include/clang/Basic/PartialDiagnostic.h:68: error: within this context
> 
> This error looks legit to me.  The code appears to be violating C++03 11.4.2 [class.friend] and 11.8.1 [class.access.nest].  Granting friendship to a class does not confer friendship to nested classes of the befriended class.  Since, as far as I know, there is no way to forward declare a nested class without first defining the parent class, nor to grant friendship to a nested class of an undefined class, I "fixed" this by proxying the enum constants through the befriended class.  It might make more sense to simply make these few enum types public.
> 
> llvm-trunk/tools/clang/include/clang/Parse/Parser.h: In destructor 'clang::Parser::BalancedDelimiterTracker::~BalancedDelimiterTracker()':
> llvm-trunk/tools/clang/include/clang/Parse/Parser.h:439: error: 'void clang::Parser::DelimiterTracker::pop(clang::tok::TokenKind)' is private
> llvm-trunk/tools/clang/include/clang/Parse/Parser.h:479: error: within this context
> 
> This error also looks legit to me.  A nested class is attempting to access a private method of a peer nested class without being declared a friend.  This appears to me to violate C++03 11.8.1 [class.access.nest].  The patch adds a friendship declaration and a forward declaration for the befriended class.


I went ahead and committed this as r144161, thanks!

	- Doug