diff options
Diffstat (limited to 'configure.ac')
| -rw-r--r-- | configure.ac | 60 |
1 files changed, 42 insertions, 18 deletions
diff --git a/configure.ac b/configure.ac index 21879c933c..860109e60a 100644 --- a/configure.ac +++ b/configure.ac @@ -466,6 +466,17 @@ AC_ARG_ENABLE([scv], AS_IF([[test "$use_scv" != "no"]],[AC_DEFINE(USE_PPC_SCV)]) +dnl Build glibc with _FORTIFY_SOURCE +AC_ARG_ENABLE(fortify-source, + AS_HELP_STRING([--enable-fortify-source@<:@=1|2|3@:>@], + [Use -D_FORTIFY_SOURCE=[1|2|3] to control code hardening, defaults to highest possible value supported by the build compiler.]), + [enable_fortify_source=$enableval], + [enable_fortify_source=no]) +case "$enable_fortify_source" in +1|2|3|no|yes) ;; +*) AC_MSG_ERROR([Not a valid argument for --enable-fortify-source: "$enable_fortify_source"]);; +esac + # We keep the original values in `$config_*' and never modify them, so we # can write them unchanged into config.make. Everything else uses # $machine, $vendor, and $os, and changes them whenever convenient. @@ -1559,24 +1570,37 @@ if test "x$have_selinux" = xyes; then fi AC_SUBST(have_selinux) -CPPUNDEFS= -dnl Check for silly hacked compilers predefining _FORTIFY_SOURCE. -dnl Since we are building the implementations of the fortified functions here, -dnl having the macro defined interacts very badly. -dnl _FORTIFY_SOURCE requires compiler optimization level 1 (gcc -O1) -dnl and above (see "man FEATURE_TEST_MACROS"). -dnl So do NOT replace AC_COMPILE_IFELSE with AC_PREPROC_IFELSE. -AC_CACHE_CHECK([for _FORTIFY_SOURCE predefine], libc_cv_predef_fortify_source, -[AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[ -#ifdef _FORTIFY_SOURCE -# error bogon -#endif]])], - [libc_cv_predef_fortify_source=no], - [libc_cv_predef_fortify_source=yes])]) -if test $libc_cv_predef_fortify_source = yes; then - CPPUNDEFS="${CPPUNDEFS:+$CPPUNDEFS }-U_FORTIFY_SOURCE" -fi -AC_SUBST(CPPUNDEFS) +dnl Check if we support the requested _FORTIFY_SOURCE level +dnl If not, then don't use it. +dnl Note that _FORTIFY_SOURCE may have been set through FLAGS too. +dnl _FORTIFY_SOURCE value will be selectively disabled for function that can't +dnl support it +no_fortify_source="-Wp,-U_FORTIFY_SOURCE" +fortify_source="${no_fortify_source}" + +AC_CACHE_CHECK([for __builtin_dynamic_object_size], [libc_cv___builtin_dynamic_object_size], [ + AC_LINK_IFELSE([AC_LANG_PROGRAM([], [__builtin_dynamic_object_size("", 0)])], + [libc_cv___builtin_dynamic_object_size=yes + AS_IF([test "$enable_fortify_source" = yes], [enable_fortify_source=3])], + [libc_cv___builtin_dynamic_object_size=no + AS_IF([test "$enable_fortify_source" = yes], [enable_fortify_source=2])]) +]) + +AS_CASE([$enable_fortify_source], + [1|2], [libc_cv_fortify_source=yes], + [3], [AS_IF([test "$libc_cv___builtin_dynamic_object_size" = yes], + [libc_cv_fortify_source=yes], + [AC_MSG_ERROR([Compiler doesn't provide necessary support for _FORTIFY_SOURCE=3])])], + [libc_cv_fortify_source=no]) + +AS_IF([test "$libc_cv_fortify_source" = yes], + [fortify_source="${fortify_source},-D_FORTIFY_SOURCE=${enable_fortify_source}"] + ) + +AC_SUBST(enable_fortify_source) +AC_SUBST(libc_cv_fortify_source) +AC_SUBST(no_fortify_source) +AC_SUBST(fortify_source) dnl Starting with binutils 2.35, GAS can attach multiple symbol versions dnl to one symbol (PR 23840). |