Remove configure test for needing -P for .S files.

There is a configure test for "whether we need to use -P to assemble
.S files".

I think this test is long obsolete.  I don't have a specific reference
to a binutils change or version that obsoleted this test, but: (a) we
only support GNU binutils; (b) it looks like every architecture
supported by glibc has '#' as a line comment character in its gas
port; (c) in any case, if the (compiler, assembler) combination in use
cannot compile a .S file without special options, that would clearly
be a substantially broken combination, which I don't think we need to
allow for at all.

The test in question was added by:

Thu Jan 27 16:46:03 1994  Roland McGrath  (roland@churchy.gnu.ai.mit.edu)

        * configure.in (asm-CPPFLAGS): Add new check to see if assembling
        a .S file loses without -P.  If so, set asm-CPPFLAGS=-P in config.make.

This patch removes the test and the reference to this issue in the
comment on the default empty definition of asm-CPPFLAGS.  (Various
other settings of asm-CPPFLAGS remain in sysdeps Makefile fragments.)

Tested for x86_64 and x86 (testsuite, and that installed shared
libraries are unchanged by the patch).

	* configure.ac (libc_cv_need_minus_P): Remove configure test.
	* configure: Regenerated.
	* Makeconfig (asm-CPPFLAGS): Remove reference to -P in comment.

4 files changed, 7 insertions, 48 deletions

diff --git a/ChangeLog b/ChangeLog
index 7c0072b88e..38cb052307 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2015-10-27  Joseph Myers  <joseph@codesourcery.com>
+
+	* configure.ac (libc_cv_need_minus_P): Remove configure test.
+	* configure: Regenerated.
+	* Makeconfig (asm-CPPFLAGS): Remove reference to -P in comment.
+
 2015-10-26  Joseph Myers  <joseph@codesourcery.com>
 
 	* configure.ac (old_glibc_headers): Remove configure test.
diff --git a/Makeconfig b/Makeconfig
index f3668c616a..c0f5e64ef5 100644
--- a/Makeconfig
+++ b/Makeconfig
@@ -345,9 +345,7 @@ endif
 endif
 
 # Flags to pass the C compiler when assembling preprocessed assembly code
-# (`.S' files).  On some systems the assembler doesn't understand the `#' line
-# directives the preprocessor produces.  If you have troubling compiling
-# assembly code, try using -P here to suppress these directives.
+# (`.S' files).
 ifndef asm-CPPFLAGS
 asm-CPPFLAGS =
 endif
diff --git a/configure b/configure
index 22aa1b9372..1e9eba10b7 100755
--- a/configure
+++ b/configure
@@ -5272,34 +5272,6 @@ if test $ac_verc_fail = yes; then
 fi
 
 
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether we need to use -P to assemble .S files" >&5
-$as_echo_n "checking whether we need to use -P to assemble .S files... " >&6; }
-if ${libc_cv_need_minus_P+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  cat > conftest.S <<EOF
-#include "confdefs.h"
-/* Nothing whatsoever.  */
-EOF
-if { ac_try='${CC-cc} $CPPFLAGS $ASFLAGS -c conftest.S 1>&5'
-  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
-  (eval $ac_try) 2>&5
-  ac_status=$?
-  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
-  test $ac_status = 0; }; }; then
-  libc_cv_need_minus_P=no
-else
-  libc_cv_need_minus_P=yes
-fi
-rm -f conftest*
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_need_minus_P" >&5
-$as_echo "$libc_cv_need_minus_P" >&6; }
-if test $libc_cv_need_minus_P = yes; then
-  config_vars="$config_vars
-asm-CPPFLAGS = -P # The assembler can't grok cpp's # line directives."
-fi
-
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for .set assembler directive" >&5
 $as_echo_n "checking for .set assembler directive... " >&6; }
 if ${libc_cv_asm_set_directive+:} false; then :
diff --git a/configure.ac b/configure.ac
index 6947555be4..4879c48db7 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1080,23 +1080,6 @@ AC_CHECK_PROG_VER(BISON, bison, --version,
 		  [2.7*|[3-9].*|[1-9][0-9]*],
 		  BISON=no)
 
-AC_CACHE_CHECK(whether we need to use -P to assemble .S files,
-	       libc_cv_need_minus_P, [dnl
-cat > conftest.S <<EOF
-#include "confdefs.h"
-/* Nothing whatsoever.  */
-EOF
-if AC_TRY_COMMAND(${CC-cc} $CPPFLAGS $ASFLAGS -c conftest.S 1>&AS_MESSAGE_LOG_FD); then
-  libc_cv_need_minus_P=no
-else
-  libc_cv_need_minus_P=yes
-fi
-rm -f conftest*])
-if test $libc_cv_need_minus_P = yes; then
-  config_vars="$config_vars
-asm-CPPFLAGS = -P # The assembler can't grok cpp's # line directives."
-fi
-
 AC_CACHE_CHECK(for .set assembler directive, libc_cv_asm_set_directive, [dnl
 cat > conftest.s <<EOF
 .text