this allows gcc4.9.3 to build on OSX10

var/spack/repos/builtin/packages/gcc/darwin/gcc-4.9.patch1

+diff --git a/gcc/configure b/gcc/configure
+index 9523773..52b0bf7 100755
+--- a/gcc/configure
++++ b/gcc/configure
+@@ -24884,7 +24884,7 @@ if test "${gcc_cv_as_ix86_filds+set}" = set; then :
+ else
+   gcc_cv_as_ix86_filds=no
+   if test x$gcc_cv_as != x; then
+-    $as_echo 'filds mem; fists mem' > conftest.s
++    $as_echo 'filds (%ebp); fists (%ebp)' > conftest.s
+     if { ac_try='$gcc_cv_as $gcc_cv_as_flags  -o conftest.o conftest.s >&5'
+   { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+   (eval $ac_try) 2>&5
+@@ -24915,7 +24915,7 @@ if test "${gcc_cv_as_ix86_fildq+set}" = set; then :
+ else
+   gcc_cv_as_ix86_fildq=no
+   if test x$gcc_cv_as != x; then
+-    $as_echo 'fildq mem; fistpq mem' > conftest.s
++    $as_echo 'fildq (%ebp); fistpq (%ebp)' > conftest.s
+     if { ac_try='$gcc_cv_as $gcc_cv_as_flags  -o conftest.o conftest.s >&5'
+   { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+   (eval $ac_try) 2>&5
+diff --git a/gcc/configure.ac b/gcc/configure.ac
+index 68b0ee8..bd53978 100644
+--- a/gcc/configure.ac
++++ b/gcc/configure.ac
+@@ -3869,13 +3869,13 @@ foo:	nop
+ 
+     gcc_GAS_CHECK_FEATURE([filds and fists mnemonics],
+        gcc_cv_as_ix86_filds,,,
+-       [filds mem; fists mem],,
++       [filds (%ebp); fists (%ebp)],,
+        [AC_DEFINE(HAVE_AS_IX86_FILDS, 1,
+          [Define if your assembler uses filds and fists mnemonics.])])
+ 
+     gcc_GAS_CHECK_FEATURE([fildq and fistpq mnemonics],
+        gcc_cv_as_ix86_fildq,,,
+-       [fildq mem; fistpq mem],,
++       [fildq (%ebp); fistpq (%ebp)],,
+        [AC_DEFINE(HAVE_AS_IX86_FILDQ, 1,
+          [Define if your assembler uses fildq and fistq mnemonics.])])
+ 

var/spack/repos/builtin/packages/gcc/darwin/gcc-4.9.patch2

+From 82f81877458ea372176eabb5de36329431dce99b Mon Sep 17 00:00:00 2001
+From: Iain Sandoe <iain@codesourcery.com>
+Date: Sat, 21 Dec 2013 00:30:18 +0000
+Subject: [PATCH] don't try to mark local symbols as no-dead-strip
+
+---
+ gcc/config/darwin.c | 5 +++++
+ 1 file changed, 5 insertions(+)
+
+diff --git a/gcc/config/darwin.c b/gcc/config/darwin.c
+index 40804b8..0080299 100644
+--- a/gcc/config/darwin.c
++++ b/gcc/config/darwin.c
+@@ -1259,6 +1259,11 @@ darwin_encode_section_info (tree decl, rtx rtl, int first ATTRIBUTE_UNUSED)
+ void
+ darwin_mark_decl_preserved (const char *name)
+ {
++  /* Actually we shouldn't mark any local symbol this way, but for now
++     this only happens with ObjC meta-data.  */
++  if (darwin_label_is_anonymous_local_objc_name (name))
++    return;
++
+   fprintf (asm_out_file, "\t.no_dead_strip ");
+   assemble_name (asm_out_file, name);
+   fputc ('\n', asm_out_file);
+-- 
+2.2.1
+

var/spack/repos/builtin/packages/gcc/package.py

@@ -27,6 +27,7 @@
 from contextlib import closing
 from glob import glob
 import sys
+import os
 
 class Gcc(Package):
     """The GNU Compiler Collection includes front ends for C, C++,
@@ -63,6 +64,9 @@ class Gcc(Package):
     # TODO: integrate these libraries.
     #depends_on("ppl")
     #depends_on("cloog")
+    if sys.platform == 'darwin':
+        patch('darwin/gcc-4.9.patch1', when='@4.9.3')
+        patch('darwin/gcc-4.9.patch2', when='@4.9.3')
 
     def install(self, spec, prefix):
         # libjava/configure needs a minor fix to install into spack paths.
@@ -70,6 +74,7 @@ def install(self, spec, prefix):
             string=True)
 
         enabled_languages = set(('c', 'c++', 'fortran', 'java', 'objc'))
+
         if spec.satisfies("@4.7.1:") and sys.platform != 'darwin':
             enabled_languages.add('go')
 
@@ -101,12 +106,17 @@ def install(self, spec, prefix):
             isl_options = ["--with-isl=%s" % spec['isl'].prefix]
             options.extend(isl_options)
 
+        if sys.platform == 'darwin' :
+            darwin_options = [ "--with-build-config=bootstrap-debug" ]
+            options.extend(darwin_options)
+
         build_dir = join_path(self.stage.path, 'spack-build')
         configure = Executable( join_path(self.stage.source_path, 'configure') )
         with working_dir(build_dir, create=True):
             # Rest of install is straightforward.
             configure(*options)
-            make()
+            if sys.platform == 'darwin' : make("bootstrap")
+            else: make()
             make("install")
 
         self.write_rpath_specs()