[Bug c++/23885] incorrect template two-stage name-lookup

["rockeet at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23885

rockeet <rockeet at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rockeet at gmail dot com

--- Comment #9 from rockeet <rockeet at gmail dot com> 2011-12-13 09:35:29 UTC ---
///// Code Begin
#include <stdio.h>

class A {}; void f(A) { printf("%s\n", __PRETTY_FUNCTION__); }
class B {};
template<class T> void f(T) { printf("%s\n", __PRETTY_FUNCTION__); }

// now g(T) knew A,B,int,...
// phase 1 lookup just success for f(A)
template<class T> void g(T x) { f(x); }

// after definition of g(T) and class B
void f(B) { printf("%s\n", __PRETTY_FUNCTION__); }

void f(int x) { printf("%s\n", __PRETTY_FUNCTION__); }
void f(int*x) { printf("%s\n", __PRETTY_FUNCTION__); }

int main(int argc, char** argv) {
    g(A());   // should always(phase 1 and phase 2) be OK
    g(B());   // f(B) definition is after g(T) definition, phase 1 just got
f(A) and f(T)
    g(B());   //      but phase 2 got f(B)
    g(100);   // intend to let g calling f(int), but got f(T) in g++ 4.1.2 and
4.6.0, 4.7.0, others not tested
    g(&argc); // intention: similar as g(100)
    return 0;
}
///// Code End

The output of above code shown that "associated sets of namespaces and
classes of fundamental types are both empty" is really true! But pre g++ 3.4.6
and clang treat fundamental types as same as user defined types.

//// Begin Compile With g++ 4.6.0
$g++ -v
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/opt/libexec/gcc/x86_64-unknown-linux-gnu/4.6.0/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: ../gcc-4.6.0-src/configure --prefix=/opt --with-gmp=/opt
--with-mpfr=/opt --with-mpc=/opt --with-ppl=/opt --with-cloog=/opt
--with-local-prefix=/opt --enable-languages=c,c++
Thread model: posix
gcc version 4.6.0 (GCC) 
$ g++ twophaselookup2.cpp
$ ./a.out 
//// End Compile With g++ 4.6.0

//// Begin Compile With g++ 3.4.6
void f(A)
void f(B)
void f(B)
void f(int)
void f(int*)
//// Begin Compile With g++ 3.4.6

apple clang produced the same result as g++ 3.4.6