gcc: Add patch to handle on target multilibs better

On target multilibs did not work properly since gcc-cross-canadian
was only searching a limited number of sysroot directories to
find multilib target binaries.

This adds an extra search path to ensure those binaries are found
and our gcc-cross-canadian works everywhere we need it to, e.g.
with mips trilib configurations.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 88 insertions, 0 deletions

diff --git a/meta/recipes-devtools/gcc/gcc-4.9/0064-handle-target-sysroot-multilib.patch b/meta/recipes-devtools/gcc/gcc-4.9/0064-handle-target-sysroot-multilib.patch
new file mode 100644
index 0000000000..53569847f2
--- /dev/null
+++ b/meta/recipes-devtools/gcc/gcc-4.9/0064-handle-target-sysroot-multilib.patch
@@ -0,0 +1,88 @@
+Search target sysroot gcc version specific dirs with multilib.
+
+We install the gcc libraries (such as crtbegin.p) into
+<sysroot><libdir>/<target-sys>/5.2.0/
+which is a default search path for GCC (aka multi_suffix in the 
+code below). <target-sys> is 'machine' in gcc's terminology. We use
+these directories so that multiple gcc versions could in theory 
+co-exist on target.
+
+We only want to build one gcc-cross-canadian per arch and have this work 
+for all multilibs. <target-sys> can be handled by mapping the multilib
+<target-sys> to the one used by gcc-cross-canadian, e.g. mips64-polkmllib32-linux 
+is symlinked to by mips64-poky-linux.
+
+The default gcc search path in the target sysroot for a "lib64" mutlilib is:
+
+<sysroot>/lib32/mips64-poky-linux/5.2.0/
+<sysroot>/lib32/../lib64/
+<sysroot>/usr/lib32/mips64-poky-linux/5.2.0/
+<sysroot>/usr/lib32/../lib64/
+<sysroot>/lib32/
+<sysroot>/usr/lib32/
+
+which means that the lib32 crtbegin.o will be found and the lib64 ones
+will not which leads to compiler failures.
+
+This patch injects a multilib version of that path first so the lib64
+binaries can be found first. With this change the search path becomes:
+
+<sysroot>/lib32/../lib64/mips64-poky-linux/5.2.0/
+<sysroot>/lib32/mips64-poky-linux/5.2.0/
+<sysroot>/lib32/../lib64/
+<sysroot>/usr/lib32/../lib64/mips64-poky-linux/5.2.0/
+<sysroot>/usr/lib32/mips64-poky-linux/5.2.0/
+<sysroot>/usr/lib32/../lib64/
+<sysroot>/lib32/
+<sysroot>/usr/lib32/
+
+Upstream-Status: Pending
+RP 2015/7/31
+
+Index: gcc-5.2.0/gcc/gcc.c
+===================================================================
+--- gcc-5.2.0.orig/gcc/gcc.c
++++ gcc-5.2.0/gcc/gcc.c
+@@ -2305,7 +2305,7 @@ for_each_path (const struct path_prefix
+       if (path == NULL)
+ 	{
+ 	  len = paths->max_len + extra_space + 1;
+-	  len += MAX (MAX (suffix_len, multi_os_dir_len), multiarch_len);
++	  len += MAX ((suffix_len + multi_os_dir_len), multiarch_len);
+ 	  path = XNEWVEC (char, len);
+ 	}
+ 
+@@ -2317,6 +2317,33 @@ for_each_path (const struct path_prefix
+ 	  /* Look first in MACHINE/VERSION subdirectory.  */
+ 	  if (!skip_multi_dir)
+ 	    {
++	      if (!(pl->os_multilib ? skip_multi_os_dir : skip_multi_dir))
++	        {
++	          const char *this_multi;
++	          size_t this_multi_len;
++
++	          if (pl->os_multilib)
++		    {
++		      this_multi = multi_os_dir;
++		      this_multi_len = multi_os_dir_len;
++		    }
++	          else
++		    {
++		      this_multi = multi_dir;
++		      this_multi_len = multi_dir_len;
++		    }
++
++	          /* Look in multilib MACHINE/VERSION subdirectory first */
++	          if (this_multi_len)
++	            {
++		      memcpy (path + len, this_multi, this_multi_len + 1);
++	              memcpy (path + len + this_multi_len, multi_suffix, suffix_len + 1);
++	              ret = callback (path, callback_info);
++	                if (ret)
++		          break;
++	            }
++	        }
++
+ 	      memcpy (path + len, multi_suffix, suffix_len + 1);
+ 	      ret = callback (path, callback_info);
+ 	      if (ret)