[Bug testsuite/48245] FAIL: gcc.dg/lto/pr46940 c_lto_pr46940_0.o assemble on *-apple-darwin*

["iains at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48245

Iain Sandoe <iains at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2011.03.23 17:07:04
     Ever Confirmed|0                           |1

--- Comment #7 from Iain Sandoe <iains at gcc dot gnu.org> 2011-03-23 17:07:04 UTC ---
I'll try this on *-darwin9 and a  darwin9-X-cris-elf
(I assume we need to clone all the logic to cater for cross compiler cases... )

maybe this is getting complex enough to warrant a spec of its own? (and then we
could avoid cloning it)

===

Index: gcc/config/darwin.h
===================================================================
--- gcc/config/darwin.h    (revision 171353)
+++ gcc/config/darwin.h    (working copy)
@@ -174,6 +174,38 @@ extern GTY(()) int darwin_ms_struct;
 #define CPP_SPEC "%{static:%{!dynamic:-D__STATIC__}}%{!static:-D__DYNAMIC__}"
\
     " %{pthread:-D_REENTRANT}"

+/* Conditional to test whether the LTO plugin is used or not.
+   FIXME: For slim LTO we will need to enable plugin unconditionally.  This
+   still cause problems with PLUGIN_LD != LD and when plugin is built but
+   not useable.  For GCC 4.6 we don't support slim LTO and thus we can enable
+   plugin only when LTO is enabled.  We still honor explicit
+   -fuse-linker-plugin if the linker used understands -plugin.  */
+
+/* The linker has some plugin support.  */
+#if HAVE_LTO_PLUGIN > 0
+/* The linker used has full plugin support, use LTO plugin by default.  */
+#if HAVE_LTO_PLUGIN == 2
+#define PLUGIN_COND "!fno-use-linker-plugin:%{flto|flto=*|fuse-linker-plugin"
+#define PLUGIN_COND_CLOSE "}"
+#else
+/* The linker used has limited plugin support, use LTO plugin with explicit
+   -fuse-linker-plugin.  */
+#define PLUGIN_COND "fuse-linker-plugin"
+#define PLUGIN_COND_CLOSE ""
+#endif
+#define LINK_PLUGIN_SPEC \
+    "%{"PLUGIN_COND": \
+    -plugin %(linker_plugin_file) \
+    -plugin-opt=%(lto_wrapper) \
+    -plugin-opt=-fresolution=%u.res \
+    %{!nostdlib:%{!nodefaultlibs:%:pass-through-libs(%(link_gcc_c_sequence))}}
\
+    }"PLUGIN_COND_CLOSE
+#else
+/* The linker used doesn't support -plugin, reject -fuse-linker-plugin.  */
+#define LINK_PLUGIN_SPEC "%{fuse-linker-plugin:\
+    %e-fuse-linker-plugin is not supported in this configuration}"
+#endif
+
 /* This is mostly a clone of the standard LINK_COMMAND_SPEC, plus
    precomp, libtool, and fat build additions.

@@ -185,6 +217,7 @@ extern GTY(()) int darwin_ms_struct;
 #define LINK_COMMAND_SPEC_A \
    "%{!fdump=*:%{!fsyntax-only:%{!c:%{!M:%{!MM:%{!E:%{!S:\
     %(linker) \
+    " LINK_PLUGIN_SPEC " \
     %{flto*:%<fcompare-debug*} \
     %{flto*} \
     %l %X %{s} %{t} %{Z} %{u*} \