[testsuite] Fix plugin test for bareboard ports

[Eric Botcazou <ebotcazou at adacore dot com>]

Hi,

if you run a test for a bareboard port, e.g. arm-eabi or visium-elf, you'll 
see in gcc.log:

Running /home/eric/svn/gcc/gcc/testsuite/gcc.dg/dg.exp ...
Executing on host: /home/eric/build/gcc/arm-eabi/gcc/xgcc -
B/home/eric/build/gcc/arm-eabi/gcc/ linker_plugin14260.c  -fno-diagnostics-
show-caret -fdiagnostics-color=never  -flto -fuse-linker-plugin  -lm    -o 
linker_plugin14260.exe    (timeout = 300)
spawn /home/eric/build/gcc/arm-eabi/gcc/xgcc -B/home/eric/build/gcc/arm-
eabi/gcc/ linker_plugin14260.c -fno-diagnostics-show-caret -fdiagnostics-
color=never -flto -fuse-linker-plugin -lm -o linker_plugin14260.exe
/home/eric/install/gcc/arm-eabi/bin/ld: cannot find crt0.o: No such file or 
directory
collect2: error: ld returned 1 exit status
compiler exited with status 1

Failure of the plugin test will in turn cause gcc.c-torture/compile/pr61848.c 
to fail in LTO mode:

FAIL: gcc.c-torture/compile/pr61848.c   -O2 -flto   scan-assembler mysection
FAIL: gcc.c-torture/compile/pr61848.c   -O2 -flto -flto-partition=none   scan-
assembler mysection

because of the fat/thin LTO object mismatch.

The attached patch fixes it by ensuring that LTO_TORTURE_OPTIONS is computed 
after set_ld_library_path_env_vars is invoked (this procedure invokes in turn 
set_gcc_exec_prefix_env_var), both in c-torture.exp and in gcc-dg.exp.

Tested on x86_64-suse-linux and visium-elf, OK for the mainline?


2015-01-15  Eric Botcazou  <ebotcazou@adacore.com>

	* lib/c-torture.exp: Compute LTO_TORTURE_OPTIONS after the environment
	is set up.
	* lib/gcc-dg.exp: Likewise.


-- 
Eric Botcazou

Index: lib/gcc-dg.exp
===================================================================
--- lib/gcc-dg.exp	(revision 219578)
+++ lib/gcc-dg.exp	(working copy)
@@ -72,7 +72,14 @@ if [info exists ADDITIONAL_TORTURE_OPTIO
 	[concat $DG_TORTURE_OPTIONS $ADDITIONAL_TORTURE_OPTIONS]
 }
 
-set LTO_TORTURE_OPTIONS ""
+global orig_environment_saved
+
+# This file may be sourced, so don't override environment settings
+# that have been previously setup.
+if { $orig_environment_saved == 0 } {
+    append ld_library_path [gcc-set-multilib-library-path $GCC_UNDER_TEST]
+    set_ld_library_path_env_vars
+}
 
 # Some torture-options cause intermediate code output, unusable for
 # testing using e.g. scan-assembler.  In this variable are the options
@@ -80,6 +87,7 @@ set LTO_TORTURE_OPTIONS ""
 global gcc_force_conventional_output
 set gcc_force_conventional_output ""
 
+set LTO_TORTURE_OPTIONS ""
 if [check_effective_target_lto] {
     # When having plugin test both slim and fat LTO and plugin/nonplugin
     # path.
@@ -97,15 +105,6 @@ if [check_effective_target_lto] {
     }
 }
 
-global orig_environment_saved
-
-# This file may be sourced, so don't override environment settings
-# that have been previously setup.
-if { $orig_environment_saved == 0 } {
-    append ld_library_path [gcc-set-multilib-library-path $GCC_UNDER_TEST]
-    set_ld_library_path_env_vars
-}
-
 # Define gcc callbacks for dg.exp.
 
 proc gcc-dg-test-1 { target_compile prog do_what extra_tool_flags } {
Index: lib/c-torture.exp
===================================================================
--- lib/c-torture.exp	(revision 219578)
+++ lib/c-torture.exp	(working copy)
@@ -51,6 +51,20 @@ if [info exists ADDITIONAL_TORTURE_OPTIO
 	[concat $C_TORTURE_OPTIONS $ADDITIONAL_TORTURE_OPTIONS]
 }
 
+global GCC_UNDER_TEST
+if ![info exists GCC_UNDER_TEST] {
+    set GCC_UNDER_TEST "[find_gcc]"
+}
+
+global orig_environment_saved
+
+# This file may be sourced, so don't override environment settings
+# that have been previously setup.
+if { $orig_environment_saved == 0 } {
+    append ld_library_path [gcc-set-multilib-library-path $GCC_UNDER_TEST]
+    set_ld_library_path_env_vars
+}
+
 set LTO_TORTURE_OPTIONS ""
 if [check_effective_target_lto] {
     # When having plugin test both slim and fat LTO and plugin/nonplugin
@@ -68,20 +82,6 @@ if [check_effective_target_lto] {
     }
 }
 
-global GCC_UNDER_TEST
-if ![info exists GCC_UNDER_TEST] {
-    set GCC_UNDER_TEST "[find_gcc]"
-}
-
-global orig_environment_saved
-
-# This file may be sourced, so don't override environment settings
-# that have been previously setup.
-if { $orig_environment_saved == 0 } {
-    append ld_library_path [gcc-set-multilib-library-path $GCC_UNDER_TEST]
-    set_ld_library_path_env_vars
-}
-
 #
 # c-torture-compile -- runs the Tege C-torture test
 #