Add -fuse-ld flag to CFLAGS during configure
authorBen Gamari <bgamari.foss@gmail.com>
Mon, 3 Jul 2017 23:09:39 +0000 (19:09 -0400)
committerBen Gamari <ben@smart-cactus.org>
Mon, 3 Jul 2017 23:42:21 +0000 (19:42 -0400)
The decisions made by configure later in the script may depend upon the
linker used. Consequently, it is important that configure uses the same
linker as GHC will eventually use.

For instance, on Nix I found that a program requiring `libpthread` would
link fine with only `-lrt` when linked with BFD ld. However, with gold
we needed to explicitly provide the `-lpthread` dependency. Presumably
the former would happily loaded any `NEEDED` libraries whereas the
latter wants them explicitly given. Regardless, since `configure`'s
`NEED_PTHREAD_LIB` check didn't use the `-fuse-ld` flag that GHC would
eventually use, we inferred the wrong value, resulting in link errors
later in the build.

Test Plan: Validate

Reviewers: austin, hvr

Subscribers: rwbarton, thomie, erikd

GHC Trac Issues: #13541

Differential Revision: https://phabricator.haskell.org/D3694

configure.ac
distrib/configure.ac.in

index 92d3714..c31deba 100644 (file)
@@ -535,6 +535,7 @@ FIND_LD([$target],[GccUseLdOpt])
 CONF_GCC_LINKER_OPTS_STAGE1="$CONF_GCC_LINKER_OPTS_STAGE1 $GccUseLdOpt"
 CONF_GCC_LINKER_OPTS_STAGE2="$CONF_GCC_LINKER_OPTS_STAGE2 $GccUseLdOpt"
 LdCmd="$LD"
+CFLAGS="$CFLAGS $GccUseLdOpt"
 AC_SUBST([LdCmd])
 
 dnl ** Which nm to use?
index 53c79e1..ac6af24 100644 (file)
@@ -121,6 +121,7 @@ FIND_LD([$target],[GccUseLdOpt])
 CONF_GCC_LINKER_OPTS_STAGE1="$CONF_GCC_LINKER_OPTS_STAGE1 $GccUseLdOpt"
 CONF_GCC_LINKER_OPTS_STAGE2="$CONF_GCC_LINKER_OPTS_STAGE2 $GccUseLdOpt"
 LdCmd="$LD"
+CFLAGS="$CFLAGS $GccUseLdOpt"
 AC_SUBST([LdCmd])
 
 FP_PROG_LD_IS_GNU