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Diffstat (limited to 'm4macros/ax_isc_rpath.m4')
| -rw-r--r-- | m4macros/ax_isc_rpath.m4 | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/m4macros/ax_isc_rpath.m4 b/m4macros/ax_isc_rpath.m4 new file mode 100644 index 0000000..cae89b9 --- /dev/null +++ b/m4macros/ax_isc_rpath.m4 @@ -0,0 +1,64 @@ +dnl @synopsis AX_ISC_RPATH +dnl +dnl @summary figure out whether and which "rpath" linker option is available +dnl +dnl This macro checks if the linker supports an option to embed a path +dnl to a runtime library (often installed in an uncommon place), such as the +dnl commonly used -R option. If found, it sets the ISC_RPATH_FLAG variable to +dnl the found option flag. The main configure.ac can use it as follows: +dnl if test "x$ISC_RPATH_FLAG" != "x"; then +dnl LDFLAGS="$LDFLAGS ${ISC_RPATH_FLAG}/usr/local/lib/some_library" +dnl fi +dnl +dnl If you pass --disable-rpath to configure, ISC_RPATH_FLAG is not set + +AC_DEFUN([AX_ISC_RPATH], [ + +AC_ARG_ENABLE(rpath, + [AS_HELP_STRING([--disable-rpath],[don't hardcode library path into binaries])], + rpath=$enableval, rpath=yes) + +if test x$rpath != xno; then + # We'll tweak both CXXFLAGS and CCFLAGS so this function will work + # whichever language is used in the main script. Note also that it's not + #LDFLAGS; technically this is a linker flag, but we've noticed $LDFLAGS + # can be placed where the compiler could interpret it as a compiler + # option, leading to subtle failure mode. So, in the check below using + # the compiler flag is safer (in the actual Makefiles the flag should be + # set in LDFLAGS). + CXXFLAGS_SAVED="$CXXFLAGS" + CXXFLAGS="$CXXFLAGS -Wl,-R/usr/lib" + CCFLAGS_SAVED="$CCFLAGS" + CCFLAGS="$CCFLAGS -Wl,-R/usr/lib" + + # check -Wl,-R and -R rather than gcc specific -rpath to be as portable + # as possible. -Wl,-R seems to be safer, so we try it first. In some + # cases -R is not actually recognized but AC_LINK_IFELSE doesn't fail due + # to that. + AC_MSG_CHECKING([whether -Wl,-R flag is available in linker]) + AC_LINK_IFELSE([AC_LANG_PROGRAM([[]], [[]])], + [AC_MSG_RESULT(yes) + ISC_RPATH_FLAG=-Wl,-R + ], + [AC_MSG_RESULT(no) + AC_MSG_CHECKING([whether -R flag is available in linker]) + + # Apple clang 5.1 is now considers unknown parameters + # passed to linker (ld) as errors. However, the same + # unknown parameters passed to compiler (g++) are merely + # treated as warnings. To make sure that we pick those + # up, is to use -Werror. + CXXFLAGS="$CXXFLAGS_SAVED -R/usr/lib" + CCFLAGS="$CCFLAGS_SAVED -R/usr/lib" + AC_LINK_IFELSE([AC_LANG_PROGRAM([[]], [[]])], + [AC_MSG_RESULT([yes; note that -R is more sensitive about the position in option arguments]) + ISC_RPATH_FLAG=-R], + [AC_MSG_RESULT(no)]) + ] + ) + + CXXFLAGS=$CXXFLAGS_SAVED + CCFLAGS=$CCFLAGS_SAVED +fi + +])dnl AX_ISC_RPATH |