2012-09-18 Benjamin Kosnik <bkoz@redhat.com>

        PR libstdc++/28811
        PR libstdc++/54482
        * configure.ac (glibcxx_lt_pic_flag,
          glibcxx_compiler_pic_flag,
          glibcxx_compiler_shared_flag): New. Use them.
        (lt_prog_compiler_pic_CXX): Set via glibcxx_*_flag(s) above.
        (pic_mode): Set to default.
        (PIC_CXXFLAGS): Remove.
        * Makefile.am (PICFLAG, PICFLAG_FOR_TARGET): Remove. Comment.
        * libsupc++/Makefile.am: Use glibcxx_ld_pic_flag and
          glibcxx_compiler_shared_flag. Comment.
        * src/c++11/Makefile.am: Same.
        * src/c++98/Makefile.am: Same.
        * src/Makefile.am: Use glibcxx_compiler_pic_flag.

        * Makefile.in: Regenerated.
        * aclocal.m4: Same.
        * configure: Same.
        * doc/Makefile.in: Same.
        * include/Makefile.in: Same.
        * libsupc++/Makefile.in: Same.
        * po/Makefile.in: Same.
        * python/Makefile.in: Same.
        * src/Makefile.in: Same.
        * src/c++11/Makefile.in: Same.
        * src/c++98/Makefile.in: Same.
        * testsuite/Makefile.in: Same.

        * src/c++11/compatibility-atomic-c++0x.cc: Use
          _GLIBCXX_SHARED instead of PIC to designate shared-only
          code blocks.
        * src/c++11/compatibility-c++0x.cc: Same.
        * src/c++11/compatibility-thread-c++0x.cc: Same.
        * src/c++98/compatibility-list-2.cc: Same.
        * src/c++98/compatibility.cc: : Same.

        * testsuite/17_intro/shared_with_static_deps.cc: New.

        * doc/xml/manual/build_hacking.xml: Separate configure from
        make/build issues, add build details.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@191509 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 33 insertions, 7 deletions

diff --git a/libstdc++-v3/configure.ac b/libstdc++-v3/configure.ac
index 3943669a7eb..aff19f58395 100644
--- a/libstdc++-v3/configure.ac
+++ b/libstdc++-v3/configure.ac
@@ -88,6 +88,7 @@ CXXFLAGS="$save_CXXFLAGS"
 # up critical shell variables.
 GLIBCXX_CONFIGURE
 
+# Libtool setup.
 if test "x${with_newlib}" != "xyes"; then
   AC_LIBTOOL_DLOPEN
 fi
@@ -96,6 +97,38 @@ ACX_LT_HOST_FLAGS
 AC_SUBST(enable_shared)
 AC_SUBST(enable_static)
 
+# libtool variables for C++ shared and position-independent compiles.
+#
+# Use glibcxx_lt_pic_flag to designate the automake variable
+# used to encapsulate the default libtool approach to creating objects
+# with position-independent code. Default: -prefer-pic.
+#
+# Use glibcxx_compiler_shared_flag to designate a compile-time flags for
+# creating shared objects. Default: -D_GLIBCXX_SHARED.
+#
+# Use glibcxx_compiler_pic_flag to designate a compile-time flags for
+# creating position-independent objects. This varies with the target
+# hardware and operating system, but is often: -DPIC -fPIC.
+if test "$enable_shared" = yes; then
+  glibcxx_lt_pic_flag="-prefer-pic"
+  glibcxx_compiler_pic_flag="$lt_prog_compiler_pic_CXX"
+  glibcxx_compiler_shared_flag="-D_GLIBCXX_SHARED"
+
+else
+  glibcxx_lt_pic_flag=
+  glibcxx_compiler_pic_flag=
+  glibcxx_compiler_shared_flag=
+fi
+AC_SUBST(glibcxx_lt_pic_flag)
+AC_SUBST(glibcxx_compiler_pic_flag)
+AC_SUBST(glibcxx_compiler_shared_flag)
+
+# Override the libtool's pic_flag and pic_mode.
+# Do this step after AM_PROG_LIBTOOL, but before AC_OUTPUT.
+# NB: this impacts --with-pic and --without-pic.
+lt_prog_compiler_pic_CXX="$glibcxx_compiler_pic_flag $glibcxx_compiler_shared_flag"
+pic_mode='default'
+
 # Eliminate -lstdc++ addition to postdeps for cross compiles.
 postdeps_CXX=`echo " $postdeps_CXX " | sed 's, -lstdc++ ,,g'`
 
@@ -430,13 +463,6 @@ GLIBCXX_EXPORT_INSTALL_INFO
 GLIBCXX_EXPORT_INCLUDES
 GLIBCXX_EXPORT_FLAGS
 
-if test "$enable_shared" = yes; then
-  PIC_CXXFLAGS="-prefer-pic"
-else
-  PIC_CXXFLAGS=
-fi
-AC_SUBST(PIC_CXXFLAGS)
-
 dnl In autoconf 2.5x, AC_OUTPUT is replaced by four AC_CONFIG_* macros,
 dnl which can all be called multiple times as needed, plus one (different)
 dnl AC_OUTPUT macro.  This one lists the files to be created: