Re: [c++] Keep tm, div_t, ldiv_t, lconv mangling on Solaris (PR libstdc++-v3/1773)

[Marc Glisse <marc dot glisse at inria dot fr>]

On Tue, 16 Aug 2011, Rainer Orth wrote:

> thanks for the hint.  This resulted in a far cleaner patch indeed.

Cool, thanks.

> 	* config/sol2-cxx.c

You are missing a closing parenthesis in there, on the line with 
DECL_NAMESPACE_STD_P. I hadn't dared modify DECL_CONTEXT(decl) because I 
was afraid of side effects.

For instance, in:
namespace std { struct tm {}; }
//void f(std::tm){}
void g(tm){}

uncommenting the middle line turns the error message from:
e.cc:3:10: error: variable or field 'g' declared void
e.cc:3:8: error: 'tm' was not declared in this scope
e.cc:3:8: note: suggested alternative:
e.cc:1:24: note:   'std::tm'

to:
e.cc:3:10: error: variable or field 'g' declared void
e.cc:3:8: error: 'tm' was not declared in this scope
e.cc:3:8: note: suggested alternative:
e.cc:1:24: note:   'tm'

It also breaks argument-dependent lookup:
namespace std { struct tm {}; void h(tm){} }
void g(std::tm x){ h(x); }

On the other hand, there probably isn't much ADL going on with these 4 
types...

It might be less invasive to have decl_mangling_context return 
global_namespace without actually modifying the expr?

(as already mentioned, I don't know much about gcc internals, I am just 
commenting from my experience writing the previous draft patch)

--
Marc Glisse