[PATCH] fix interaction of -S and -x {c,c++}-header

[Jan Beulich]

Irrespective of the use of -o this so far resulted in "error: output
filename specified twice", since cc1_options already produces a -o
option when -S was specified.

gcc/
2016-07-01  Jan Beulich  <jbeul...@suse.com>

        * varasm.c (get_variable_section): Validate initializer in
        named .bss-like sections.

gcc/testsuite/
2016-07-01  Jan Beulich  <jbeul...@suse.com>

        * gcc.dg/bss.c: New.

--- 2016-06-30/gcc/cp/lang-specs.h
+++ 2016-06-30/gcc/cp/lang-specs.h
@@ -47,7 +47,7 @@ along with GCC; see the file COPYING3.
       cc1plus %{save-temps*|no-integrated-cpp:-fpreprocessed 
%{save-temps*:%b.ii} %{!save-temps*:%g.ii}}\
              %{!save-temps*:%{!no-integrated-cpp:%(cpp_unique_options)}}\
        %(cc1_options) %2\
-       %{!fsyntax-only:-o %g.s \
+       %{!fsyntax-only:%{!S:-o %g.s} \
            %{!fdump-ada-spec*:%{!o*:--output-pch=%i.gch}\
                               %W{o*:--output-pch=%*}}%V}}}}",
      CPLUSPLUS_CPP_SPEC, 0, 0},
--- 2016-06-30/gcc/gcc.c
+++ 2016-06-30/gcc/gcc.c
@@ -1330,7 +1330,7 @@ static const struct compiler default_com
                                               %W{o*:--output-pch=%*}}%V}}\
          %{!save-temps*:%{!traditional-cpp:%{!no-integrated-cpp:\
                cc1 %(cpp_unique_options) %(cc1_options)\
-                   %{!fsyntax-only:-o %g.s \
+                   %{!fsyntax-only:%{!S:-o %g.s} \
                        %{!fdump-ada-spec*:%{!o*:--output-pch=%i.gch}\
                                           %W{o*:--output-pch=%*}}%V}}}}}}}", 
0, 0, 0},
   {".i", "@cpp-output", 0, 0, 0},
--- 2016-06-30/gcc/testsuite/g++.dg/header.C
+++ 2016-06-30/gcc/testsuite/g++.dg/header.C
@@ -0,0 +1,9 @@
+/* This really should use "dg-do compile" without the -S in dg-options,
+   but the extra options get put after the input file in that case, and
+   hence the test would fail. */
+/* { dg-do assemble } */
+/* { dg-options "-S -x c++-header" } */
+
+struct s {
+       unsigned field;
+};
--- 2016-06-30/gcc/testsuite/gcc.dg/header.c
+++ 2016-06-30/gcc/testsuite/gcc.dg/header.c
@@ -0,0 +1,9 @@
+/* This really should use "dg-do compile" without the -S in dg-options,
+   but the extra options get put after the input file in that case, and
+   hence the test would fail. */
+/* { dg-do assemble } */
+/* { dg-options "-S -x c-header" } */
+
+struct s {
+       unsigned field;
+};