gnu: gcc: Always link against libgcc_s.so.

* gnu/packages/gcc.scm (gcc-4.7)[pre-configure]: Add snippet to #undef
  USE_LD_AS_NEEDED.

1 files changed, 12 insertions, 0 deletions

diff --git a/gnu/packages/gcc.scm b/gnu/packages/gcc.scm
index db1984306e..f11e506bc7 100644
--- a/gnu/packages/gcc.scm
+++ b/gnu/packages/gcc.scm
@@ -173,6 +173,18 @@ where the OS part is overloaded to denote a specific ABI---into GCC
 ~a"
                            libc line))))
 
+              ;; Use '-lgcc_s' rather than '--as-needed -lgcc_s', so that
+              ;; libgcc_s.so is always found by those programs that use
+              ;; 'pthread_cancel' (glibc dlopens libgcc_s.so when
+              ;; pthread_cancel support is needed, but having it in the
+              ;; application's RUNPATH isn't enough; see
+              ;; <http://sourceware.org/ml/libc-help/2013-11/msg00023.html>.)
+              ;; Also, "gcc_cv_ld_as_needed=no" as a configure flag doesn't
+              ;; work.
+              (substitute* "gcc/gcc.c"
+                (("#ifndef USE_LD_AS_NEEDED.*$" line)
+                 (string-append "#undef USE_LD_AS_NEEDED\n" line)))
+
               ;; Don't retain a dependency on the build-time sed.
               (substitute* "fixincludes/fixincl.x"
                 (("static char const sed_cmd_z\\[\\] =.*;")