Remove configure tests for visibility support.

There are various configure tests for visibility support in the
compiler and assember.

GCC support for visibility attributes was added in GCC 3.3.  I don't
know what specific fix was intended by the test "for broken
__attribute__((visibility())", but it was added by
<https://sourceware.org/ml/libc-hacker/2002-08/msg00030.html>, and GCC
3.3 appears not to have that breakage, so I suspect it was only ever
in development versions before 3.3 was released.  The assembler
support was added in binutils 2.10.

This patch removes the tests in question as obsolete.  Two tests that
were formerly conditional on "if test $libc_cv_visibility_attribute =
yes", including the one for linker support for protected data, are now
unconditional.

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

	* configure.ac (libc_cv_asm_protected_directive): Remove configure
	test.
	(libc_cv_visibility_attribute): Likewise.
	(libc_cv_protected_data): Test unconditionally.
	(libc_cv_broken_visibility_attribute): Remove configure test.
	(libc_cv_have_sdata_section): Test unconditionally.
	* configure: Regenerated.

1 files changed, 26 insertions, 92 deletions

diff --git a/configure.ac b/configure.ac
index ffa44ce6d8..6a56826516 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1105,89 +1105,25 @@ if test $libc_cv_asm_set_directive = yes; then
   AC_DEFINE(HAVE_ASM_SET_DIRECTIVE)
 fi
 
-AC_CACHE_CHECK(for .protected and .hidden assembler directive,
-	       libc_cv_asm_protected_directive, [dnl
-cat > conftest.s <<EOF
-.protected foo
-foo:
-.hidden bar
-bar:
-EOF
-if AC_TRY_COMMAND(${CC-cc} -c $ASFLAGS conftest.s 1>&AS_MESSAGE_LOG_FD); then
-  libc_cv_asm_protected_directive=yes
-else
-  AC_MSG_ERROR(assembler support for symbol visibility is required)
-fi
-rm -f conftest*])
-
-if test $libc_cv_asm_protected_directive = yes; then
-  AC_CACHE_CHECK(whether __attribute__((visibility())) is supported,
-		 libc_cv_visibility_attribute,
-		 [cat > conftest.c <<EOF
-		  int foo __attribute__ ((visibility ("hidden"))) = 1;
-		  int bar __attribute__ ((visibility ("protected"))) = 1;
-EOF
-		  libc_cv_visibility_attribute=no
-		  if AC_TRY_COMMAND(${CC-cc} -Werror -S conftest.c -o conftest.s 1>&AS_MESSAGE_LOG_FD); then
-		    if grep '\.hidden.*foo' conftest.s >/dev/null; then
-		      if grep '\.protected.*bar' conftest.s >/dev/null; then
-			libc_cv_visibility_attribute=yes
-		      fi
-		    fi
-		  fi
-		  rm -f conftest.{c,s}
-		 ])
-  if test $libc_cv_visibility_attribute != yes; then
-    AC_MSG_ERROR(compiler support for visibility attribute is required)
-  fi
-fi
-
-if test $libc_cv_visibility_attribute = yes; then
-  AC_CACHE_CHECK(linker support for protected data symbol,
-		 libc_cv_protected_data,
-		 [cat > conftest.c <<EOF
-		  int bar __attribute__ ((visibility ("protected"))) = 1;
+AC_CACHE_CHECK(linker support for protected data symbol,
+	       libc_cv_protected_data,
+	       [cat > conftest.c <<EOF
+		int bar __attribute__ ((visibility ("protected"))) = 1;
 EOF
-		  libc_cv_protected_data=no
-		  if AC_TRY_COMMAND(${CC-cc} -nostdlib -nostartfiles -fPIC -shared conftest.c -o conftest.so); then
-		    cat > conftest.c <<EOF
-		    extern int bar;
-		    int main (void) { return bar; }
+		libc_cv_protected_data=no
+		if AC_TRY_COMMAND(${CC-cc} -nostdlib -nostartfiles -fPIC -shared conftest.c -o conftest.so); then
+		  cat > conftest.c <<EOF
+		  extern int bar;
+		  int main (void) { return bar; }
 EOF
-		    if AC_TRY_COMMAND(${CC-cc} -nostdlib -nostartfiles conftest.c -o conftest conftest.so); then
-		      libc_cv_protected_data=yes
-		    fi
+		  if AC_TRY_COMMAND(${CC-cc} -nostdlib -nostartfiles conftest.c -o conftest conftest.so); then
+		    libc_cv_protected_data=yes
 		  fi
-		  rm -f conftest.*
-		 ])
-else
-  libc_cv_protected_data=no
-fi
+		fi
+		rm -f conftest.*
+	       ])
 AC_SUBST(libc_cv_protected_data)
 
-if test $libc_cv_visibility_attribute = yes; then
-  AC_CACHE_CHECK(for broken __attribute__((visibility())),
-		 libc_cv_broken_visibility_attribute,
-		 [cat > conftest.c <<EOF
-		  int foo (int x);
-		  int bar (int x) __asm__ ("foo") __attribute__ ((visibility ("hidden")));
-		  int bar (int x) { return x; }
-EOF
-		  libc_cv_broken_visibility_attribute=yes
-		  if AC_TRY_COMMAND(${CC-cc} -Werror -S conftest.c -o conftest.s 1>&AS_MESSAGE_LOG_FD); then
-changequote(,)dnl
-		    if grep '\.hidden[ 	_]foo' conftest.s >/dev/null; then
-changequote([,])dnl
-		      libc_cv_broken_visibility_attribute=no
-		    fi
-		  fi
-		  rm -f conftest.c conftest.s
-		 ])
-  if test $libc_cv_broken_visibility_attribute = yes; then
-    AC_MSG_ERROR(working compiler support for visibility attribute is required)
-  fi
-fi
-
 AC_CACHE_CHECK(for broken __attribute__((alias())),
 	       libc_cv_broken_alias_attribute,
 	       [cat > conftest.c <<EOF
@@ -1211,20 +1147,18 @@ if test $libc_cv_broken_alias_attribute = yes; then
   AC_MSG_ERROR(working alias attribute support required)
 fi
 
-if test $libc_cv_visibility_attribute = yes; then
-  AC_CACHE_CHECK(whether to put _rtld_local into .sdata section,
-		 libc_cv_have_sdata_section,
-		 [echo "int i;" > conftest.c
-		  libc_cv_have_sdata_section=no
-		  if ${CC-cc} $LDFLAGS -fPIC -shared -Wl,--verbose conftest.c -o conftest.so 2>&1 \
-		     | grep '\.sdata' >/dev/null; then
-		    libc_cv_have_sdata_section=yes
-		  fi
-		  rm -f conftest.c conftest.so
-		 ])
-  if test $libc_cv_have_sdata_section = yes; then
-    AC_DEFINE(HAVE_SDATA_SECTION)
-  fi
+AC_CACHE_CHECK(whether to put _rtld_local into .sdata section,
+	       libc_cv_have_sdata_section,
+	       [echo "int i;" > conftest.c
+		libc_cv_have_sdata_section=no
+		if ${CC-cc} $LDFLAGS -fPIC -shared -Wl,--verbose conftest.c -o conftest.so 2>&1 \
+		   | grep '\.sdata' >/dev/null; then
+		  libc_cv_have_sdata_section=yes
+		fi
+		rm -f conftest.c conftest.so
+	       ])
+if test $libc_cv_have_sdata_section = yes; then
+  AC_DEFINE(HAVE_SDATA_SECTION)
 fi
 
 AC_CACHE_CHECK(for .preinit_array/.init_array/.fini_array support,