From 235c6e628199221b7885f159367614b7105547cf Mon Sep 17 00:00:00 2001 From: John Date: Wed, 4 Jun 2014 17:45:42 +0200 Subject: [PATCH] build-sys: accommodate gcc-4.9.0 link-time optimization (LTO) changes systemd fails to build (symbols not found/resolved during cgls link step) under gcc-4.9.0 due to link-time optimization (lto) changes, in particular from gcc-4.9.0/NEWS: + When using a linker plugin, compiling with the -flto option now generates slim objects files (.o) which only contain intermediate language representation for LTO. Use -ffat-lto-objects to create files which contain additionally the object code. To generate static libraries suitable for LTO processing, use gcc-ar and gcc-ranlib; to list symbols from a slim object file use gcc-nm. (Requires that ar, ranlib and nm have been compiled with plugin support.) Both -flto and -ffat-lto-objects are now needed when building and linking against static libs w/LTO. --- configure.ac | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/configure.ac b/configure.ac index 6ee4d5fed..3252e65c9 100644 --- a/configure.ac +++ b/configure.ac @@ -178,7 +178,7 @@ CC_CHECK_FLAGS_APPEND([with_cflags], [CFLAGS], [\ --param=ssp-buffer-size=4]) AS_CASE([$CFLAGS], [*-O[[12345\ ]]*], [CC_CHECK_FLAGS_APPEND([with_cflags], [CFLAGS], [\ - -flto])], + -flto -ffat-lto-objects])], [AC_MSG_RESULT([skipping -flto, optimization not enabled])]) AC_SUBST([OUR_CFLAGS], "$with_cflags $sanitizer_cflags") -- 2.30.2