[Bug libstdc++/70722] include_next in cmath skips user-defined wrapper

[trippels at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70722

Markus Trippelsdorf <trippels at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
                 CC|                            |trippels at gcc dot gnu.org
         Resolution|---                         |INVALID

--- Comment #2 from Markus Trippelsdorf <trippels at gcc dot gnu.org> ---
See: http://gcc.gnu.org/gcc-6/porting_to.html

For Firefox the following patch works for me:

diff --git a/nsprpub/config/make-system-wrappers.pl
b/nsprpub/config/make-system-wrappers.pl                                        
index fa0873a78e0a..6a3aee337908 100644                                         
--- a/nsprpub/config/make-system-wrappers.pl                                    
+++ b/nsprpub/config/make-system-wrappers.pl                                    
@@ -19,7 +19,9 @@ while (<STDIN>) {                                             
     open OUT, ">$output_dir/$_";                                               
     print OUT "#pragma GCC system_header\n";  # suppress include_next warning  
     print OUT "#pragma GCC visibility push(default)\n";                        
+   print OUT "#define _GLIBCXX_INCLUDE_NEXT_C_HEADERS\n";                      
     print OUT "#include_next \<$_\>\n";                                        
+   print OUT "#undef _GLIBCXX_INCLUDE_NEXT_C_HEADERS\n";                       
     print OUT "#pragma GCC visibility pop\n";                                  
     close OUT;                                                                 
 }