gnu: gcc@4.9: Fix FTBFS with Glibc >= 2.28.

* gnu/packages/commencement.scm (gcc-for-libstdc++): New variable.
(libstdc++-boot0): Inherit from GCC-FOR-LIBSTDC++ instead of GCC-4.9.
* gnu/packages/gcc.scm (gcc-4.9)[source](patches): Add
"gcc-4.9-libsanitizer-ustat.patch".
* gnu/packages/patches/gcc-4.9-libsanitizer-ustat.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.

1 files changed, 14 insertions, 1 deletions

diff --git a/gnu/packages/commencement.scm b/gnu/packages/commencement.scm
index 30a0ffcec9..0aa65fe638 100644
--- a/gnu/packages/commencement.scm
+++ b/gnu/packages/commencement.scm
@@ -186,12 +186,25 @@
                     ,cf)))))
      (inputs %boot0-inputs))))
 
+;; Use a "fixed" package source for this early libstdc++ variant so we can
+;; update GCC 4.9 without triggering a full rebuild.
+(define gcc-for-libstdc++
+  (package
+    (inherit gcc-4.9)
+    (source (origin
+              (inherit (package-source gcc-4.9))
+              (patches (search-patches "gcc-4.9-libsanitizer-fix.patch"
+                                       "gcc-arm-bug-71399.patch"
+                                       "gcc-asan-missing-include.patch"
+                                       "gcc-libvtv-runpath.patch"
+                                       "gcc-fix-texi2pod.patch"))))))
+
 (define libstdc++-boot0
   ;; GCC's libcc1 is always built as a shared library (the top-level
   ;; 'Makefile.def' forcefully adds --enable-shared) and thus needs to refer
   ;; to libstdc++.so.  We cannot build libstdc++-5.3 because it relies on
   ;; C++14 features missing in some of our bootstrap compilers.
-  (let ((lib (package-with-bootstrap-guile (make-libstdc++ gcc-4.9))))
+  (let ((lib (package-with-bootstrap-guile (make-libstdc++ gcc-for-libstdc++))))
     (package
       (inherit lib)
       (name "libstdc++-boot0")