Replace --enable-static-pie with --disable-default-pie

Build glibc programs and tests as PIE by default and enable static-pie
automatically if the architecture and toolchain supports it.

Also add a new configuration option --disable-default-pie to prevent
building programs as PIE.

Only the following architectures now have PIE disabled by default
because they do not work at the moment.  hppa, ia64, alpha and csky
don't work because the linker is unable to handle a pcrel relocation
generated from PIE objects.  The microblaze compiler is currently
failing with an ICE.  GNU hurd tries to enable static-pie, which does
not work and hence fails.  All these targets have default PIE disabled
at the moment and I have left it to the target maintainers to enable PIE
on their targets.

build-many-glibcs runs clean for all targets.  I also tested x86_64 on
Fedora and Ubuntu, to verify that the default build as well as
--disable-default-pie work as expected with both system toolchains.

Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>

1 files changed, 32 insertions, 24 deletions

diff --git a/configure.ac b/configure.ac
index a91a7f399c..277d3527d2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -186,11 +186,11 @@ AC_ARG_ENABLE([profile],
 			     [build profiled library @<:@default=no@:>@]),
 	      [profile=$enableval],
 	      [profile=no])
-AC_ARG_ENABLE([static-pie],
-	      AS_HELP_STRING([--enable-static-pie],
-			     [enable static PIE support and use it in the testsuite @<:@default=no@:>@]),
-	      [static_pie=$enableval],
-	      [static_pie=no])
+AC_ARG_ENABLE([default-pie],
+	      AS_HELP_STRING([--disable-default-pie],
+			     [Do not build glibc programs and the testsuite as PIE @<:@default=no@:>@]),
+	      [default_pie=$enableval],
+	      [default_pie=yes])
 AC_ARG_ENABLE([timezone-tools],
 	      AS_HELP_STRING([--disable-timezone-tools],
 			     [do not install timezone tools @<:@default=install@:>@]),
@@ -1846,7 +1846,7 @@ if eval "${CC-cc} -S conftest.c 2>&AS_MESSAGE_LOG_FD 1>&AS_MESSAGE_LOG_FD"; then
   libc_cv_pic_default=no
 fi
 rm -f conftest.*])
-AC_SUBST(libc_cv_pic_default)
+LIBC_CONFIG_VAR([build-pic-default], [$libc_cv_pic_default])
 
 AC_CACHE_CHECK([whether -fPIE is default], libc_cv_cc_pie_default,
 [libc_cv_cc_pie_default=yes
@@ -1859,30 +1859,38 @@ if eval "${CC-cc} -S conftest.c 2>&AS_MESSAGE_LOG_FD 1>&AS_MESSAGE_LOG_FD"; then
   libc_cv_cc_pie_default=no
 fi
 rm -f conftest.*])
-libc_cv_pie_default=$libc_cv_cc_pie_default
-AC_SUBST(libc_cv_cc_pie_default)
-AC_SUBST(libc_cv_pie_default)
+LIBC_CONFIG_VAR([cc-pie-default], [$libc_cv_cc_pie_default])
+
+AC_MSG_CHECKING(if we can build programs as PIE)
+if test "x$default_pie" != xno; then
+  # Disable build-pie-default if target does not support it.
+  AC_COMPILE_IFELSE([AC_LANG_SOURCE([[#ifdef PIE_UNSUPPORTED
+# error PIE is not supported
+#endif]])], [libc_cv_pie_default=yes], [libc_cv_pie_default=no])
+fi
+AC_MSG_RESULT($libc_cv_pie_default)
+LIBC_CONFIG_VAR([build-pie-default], [$libc_cv_pie_default])
+
+AC_MSG_CHECKING(if we can build static PIE programs)
+libc_cv_static_pie=$libc_cv_pie_default
+if test "x$libc_cv_pie_default" != xno \
+   -a "$libc_cv_no_dynamic_linker" = yes; then
+  # Enable static-pie if available
+  AC_COMPILE_IFELSE([AC_LANG_SOURCE([[#ifndef SUPPORT_STATIC_PIE
+# error static PIE is not supported
+#endif]])], [libc_cv_static_pie=yes], [libc_cv_static_pie=no])
+  if test "$libc_cv_static_pie" = "yes"; then
+    AC_DEFINE(ENABLE_STATIC_PIE)
+  fi
+fi
+AC_MSG_RESULT($libc_cv_static_pie)
+LIBC_CONFIG_VAR([enable-static-pie], [$libc_cv_static_pie])
 
 # Set the `multidir' variable by grabbing the variable from the compiler.
 # We do it once and save the result in a generated makefile.
 libc_cv_multidir=`${CC-cc} $CFLAGS $CPPFLAGS -print-multi-directory`
 AC_SUBST(libc_cv_multidir)
 
-if test "$static_pie" = yes; then
-  # Check target support for static PIE
-  AC_COMPILE_IFELSE([AC_LANG_SOURCE([[#ifndef SUPPORT_STATIC_PIE
-# error static PIE is not supported
-#endif]])], , AC_MSG_ERROR([the architecture does not support static PIE]))
-  # The linker must support --no-dynamic-linker.
-  if test "$libc_cv_no_dynamic_linker" != yes; then
-    AC_MSG_ERROR([linker support for --no-dynamic-linker needed])
-  fi
-  # Default to PIE.
-  libc_cv_pie_default=yes
-  AC_DEFINE(ENABLE_STATIC_PIE)
-fi
-LIBC_CONFIG_VAR([enable-static-pie], [$static_pie])
-
 AC_SUBST(profile)
 AC_SUBST(static_nss)