File 0001-Fix-check-whether-GCC-supports-__atomic_-builtins.patch of Package ghc

From ce3897ffd6e7c8b8f36b8e920168bac8c7f836ae Mon Sep 17 00:00:00 2001
From: Ilias Tsitsimpis <iliastsi@debian.org>
Date: Tue, 18 Sep 2018 17:45:17 +0200
Subject: [PATCH] Fix check whether GCC supports __atomic_ builtins

Summary:
C11 atomics are never used because:

* The program used for checking whether GCC supports
__atomic_ builtins fails with the following error:

```
  error: size mismatch in argument 2 of `__atomic_load`
   int test(int *x) { int y; __atomic_load(&x, &y, __ATOMIC_SEQ_CST); return x; }
```

* There is a typo when checking if CONF_GCC_SUPPORTS__ATOMICS equals YES,
resulting in PRIM_CFLAGS and PRIM_EXTRA_LIBRARIES never being set.

Reviewers: bgamari

Reviewed By: bgamari

Subscribers: rwbarton, erikd, carter

Differential Revision: https://phabricator.haskell.org/D5154
---
 libraries/ghc-prim/aclocal.m4   | 2 +-
 libraries/ghc-prim/configure.ac | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/libraries/ghc-prim/aclocal.m4 b/libraries/ghc-prim/aclocal.m4
index e5695385f2..81fc44c500 100644
--- a/libraries/ghc-prim/aclocal.m4
+++ b/libraries/ghc-prim/aclocal.m4
@@ -5,7 +5,7 @@ AC_DEFUN([FP_GCC_SUPPORTS__ATOMICS],
 [
    AC_REQUIRE([AC_PROG_CC])
    AC_MSG_CHECKING([whether GCC supports __atomic_ builtins])
-   echo 'int test(int *x) { int y; __atomic_load(&x, &y, __ATOMIC_SEQ_CST); return x; }' > conftest.c
+   echo 'int test(int *x) { int y; __atomic_load(x, &y, __ATOMIC_SEQ_CST); return y; }' > conftest.c
    if $CC -c conftest.c > /dev/null 2>&1; then
        CONF_GCC_SUPPORTS__ATOMICS=YES
        AC_MSG_RESULT([yes])
diff --git a/libraries/ghc-prim/configure.ac b/libraries/ghc-prim/configure.ac
index bacc89ccc8..8249be31a9 100644
--- a/libraries/ghc-prim/configure.ac
+++ b/libraries/ghc-prim/configure.ac
@@ -8,7 +8,7 @@ dnl    unregisterised, Sparc, and PPC backends.
 FP_GCC_SUPPORTS__ATOMICS
 AC_DEFINE([HAVE_C11_ATOMICS], [$CONF_GCC_SUPPORTS__ATOMICS], [Does GCC support __atomic primitives?])
 
-if test "x$CONF_GCC_SUPPORTS__ATOMICS" = YES
+if test "$CONF_GCC_SUPPORTS__ATOMICS" = "YES"
 then PRIM_CFLAGS=-DHAVE_C11_ATOMICS
      PRIM_EXTRA_LIBRARIES=atomic
 fi
-- 
2.13.7