[Bug math/21930] New: C-only gcc builtins used in <math.h> isinf

["leah at vuxu dot org" <sourceware-bugzilla at sourceware dot org>]

https://sourceware.org/bugzilla/show_bug.cgi?id=21930

            Bug ID: 21930
           Summary: C-only gcc builtins used in <math.h> isinf
           Product: glibc
           Version: 2.26
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: math
          Assignee: unassigned at sourceware dot org
          Reporter: leah at vuxu dot org
  Target Milestone: ---

Since glibc 2.26, <math.h> uses __builtin_types_compatible_p and __typeof for
isinf, which are GCC extensions that GCC 6.3 only provides in C mode.  This
means <math.h> cannot be used from C++ programs.

Whether this in itself is harmful is questionable, but it certainly is a
regression and implies at least one serious implication: the GCC 6.3
libstdc++v3 configure check "for ISO C99 support in <math.h> for C++98" now
fails, resulting in a libstdc++ <cmath> header that simply includes <math.h>,
which makes every C++ program fail to compile that correctly uses <cmath>.

-- 
You are receiving this mail because:
You are on the CC list for the bug.