[commit: ghc] master: configure: Use -Werror to check for existence of -no-pie (cbd73bb)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/cbd73bbbb7df080d5204098aa02e5f5d0d48823c/ghc

>---------------------------------------------------------------

commit cbd73bbbb7df080d5204098aa02e5f5d0d48823c
Author: Ben Gamari <bgamari.foss at gmail.com>
Date:   Thu Apr 19 15:05:50 2018 -0400

    configure: Use -Werror to check for existence of -no-pie
    
    Clang throws a warning instead of an error when it is passed -no-pie,
    
        clang: warning: argument unused during compilation: '-nopie'
        [-Wunused-command-line-argument]
    
    Consequently configure concludes that it supports -no-pie. However, this
    will fail when used with -Werror. The solution is to simply use -Werror
    in the configure check.
    
    Thanks to @goldfire for reporting this.
    
    Reviewers: hvr
    
    Subscribers: thomie, carter, goldfire
    
    Differential Revision: https://phabricator.haskell.org/D4557


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cbd73bbbb7df080d5204098aa02e5f5d0d48823c
 aclocal.m4 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/aclocal.m4 b/aclocal.m4
index a48a5af..1cef842 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -1294,7 +1294,7 @@ AC_DEFUN([FP_GCC_SUPPORTS_NO_PIE],
    AC_MSG_CHECKING([whether GCC supports -no-pie])
    echo 'int main() { return 0; }' > conftest.c
    # Some GCC versions only warn when passed an unrecognized flag.
-   if $CC -no-pie -x c /dev/null -dM -E > conftest.txt 2>&1 && ! grep -i unrecognized conftest.txt > /dev/null 2>&1; then
+   if $CC -no-pie -Werror -x c /dev/null -dM -E > conftest.txt 2>&1 && ! grep -i unrecognized conftest.txt > /dev/null 2>&1; then
        CONF_GCC_SUPPORTS_NO_PIE=YES
        AC_MSG_RESULT([yes])
    else