[Bug libstdc++/54451] c++11/random.cc build failure when _GLIBCXX_USE_C99_STDINT_TR1 is not defined in config.h

["redi at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54451

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2012-09-09
     Ever Confirmed|0                           |1

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-09-09 11:50:18 UTC ---
(In reply to comment #0)
> Commenting out '#ifdef _GLIBCXX_USE_C99_STDINT_TR1' fixed build problem, but
> I'm not sure that it is correct solution.

It's not.

(In reply to comment #1)
> etc.  Those are the only uses of it in code that I can find.

It's used in many more headers.


>  It seems like it
> isn't exactly the best name for the define (it no longer just applies to TR1),
> but it doesn't do too much.  I can't think of a case where this would not be
> desired behavior (I don't remember, but I *think* that the C++ standard says
> that those typenames should be in the standard namespace).

But the C standard requires <stdint.h> and if the OS doesn't provide that we
can't provide a useful <cstdint>.

> Anyway, it doesn't appear like removing that code will have any adverse
> effects.

It would completely break libstdc++ on platforms without <stdint.h>, such as
djgpp

The fix is simply to check for the macro in random.cc

index 50b5359..1d0723d 100644
--- a/libstdc++-v3/src/c++11/random.cc
+++ b/libstdc++-v3/src/c++11/random.cc
@@ -24,6 +24,8 @@

 #include <random>

+#ifdef _GLIBCXX_USE_C99_STDINT_TR1
+
 #if defined __i386__ || defined __x86_64__
 # include <cpuid.h>
 #endif
@@ -142,5 +144,5 @@ namespace std _GLIBCXX_VISIBILITY(default)
     0xffffffffUL, 7,
     0x9d2c5680UL, 15,
     0xefc60000UL, 18, 1812433253UL>;
-
 }
+#endif