[PATCH, testsuite, c-compat] Handle another c/l option not recognised by older GCC or clang.

[Iain Sandoe]

Hi

When using ALT_CC/CXX_UNDER_TEST in the compat/struct-layout-1 tests, the c/l 
options provided to the “alt” compiler need to avoid latest and greatest GCC 
capability.  The patch tests to see if the ‘alt’ compiler can handle 
-fno-diagnostics-show-line-numbers.

OK for trunk?
thanks
Iain

gcc/testsuite/

        * lib/c-compat.exp (compat-use-alt-compiler): handle 
-fno-diagnostics-show-line-numbers.
        (compat_setup_dfp): Likewise.

diff --git a/gcc/testsuite/lib/c-compat.exp b/gcc/testsuite/lib/c-compat.exp
index f021890..45aa80a 100644
--- a/gcc/testsuite/lib/c-compat.exp
+++ b/gcc/testsuite/lib/c-compat.exp
@@ -35,7 +35,7 @@ load_lib target-libpath.exp
 # 
 proc compat-use-alt-compiler { } {
     global GCC_UNDER_TEST ALT_CC_UNDER_TEST
-    global compat_same_alt compat_alt_caret compat_alt_color
+    global compat_same_alt compat_alt_caret compat_alt_color compat_no_line_no
     global TEST_ALWAYS_FLAGS
 
     # We don't need to do this if the alternate compiler is actually
@@ -48,6 +48,9 @@ proc compat-use-alt-compiler { } {
        if { $compat_alt_color == 0 } then {
            regsub -- "-fdiagnostics-color=never" $TEST_ALWAYS_FLAGS "" 
TEST_ALWAYS_FLAGS
        }
+       if { $compat_no_line_no == 0 } then {
+           regsub -- "-fno-diagnostics-show-line-numbers" $TEST_ALWAYS_FLAGS 
"" TEST_ALWAYS_FLAGS
+       }
        restore_gcc_exec_prefix_env_var
     }
 }
@@ -77,10 +80,12 @@ proc compat_setup_dfp { } {
     global compat_have_dfp
     global compat_alt_caret
     global compat_alt_color
+    global compat_no_line_no
     global TEST_ALWAYS_FLAGS compat_save_TEST_ALWAYS_FLAGS
 
     set compat_alt_caret 0
     set compat_alt_color 0
+    set compat_no_line_no 0
     set compat_save_TEST_ALWAYS_FLAGS $TEST_ALWAYS_FLAGS
 
     verbose "compat_setup_dfp: $compat_use_alt $compat_same_alt" 2
@@ -100,6 +105,11 @@ proc compat_setup_dfp { } {
                int dummy; } "-fdiagnostics-color=never"] != 0 } {
            set compat_alt_color 1
        }
+       if { [check_no_compiler_messages_nocache compat_alt_has_no_line_no 
object {
+               int dummy; } "-fno-diagnostics-show-line-numbers"] != 0 } {
+           set compat_no_line_no 1
+       }
+       
        compat-use-tst-compiler
     }