From 2e7bc76d84f0aa2f08bc01407ffcdca43c15f2ff Mon Sep 17 00:00:00 2001
From: Joseph Myers <joseph@codesourcery.com>
Date: Mon, 12 Sep 2022 14:34:26 +0000
Subject: [PATCH] stdatomic.h: Do not define ATOMIC_VAR_INIT for C2x
The <stdatomic.h> macro ATOMIC_VAR_INIT, previously declared obsolete,
is removed completely in C2x; disable it for C2x in GCC's
implementation. (Although ATOMIC_* are reserved names for this
header, disabling the macro for C2x still seems appropriate.)
Bootstrapped with no regressions for x86_64-pc-linux-gnu.
gcc/
* ginclude/stdatomic.h [defined __STDC_VERSION__ &&
__STDC_VERSION__ > 201710L] (ATOMIC_VAR_INIT): Do not define.
gcc/testsuite/
* gcc.dg/atomic/c2x-stdatomic-var-init-1.c: New test.
---
gcc/ginclude/stdatomic.h | 2 ++
gcc/testsuite/gcc.dg/atomic/c2x-stdatomic-var-init-1.c | 9 +++++++++
2 files changed, 11 insertions(+)
create mode 100644 gcc/testsuite/gcc.dg/atomic/c2x-stdatomic-var-init-1.c
diff --git a/gcc/ginclude/stdatomic.h b/gcc/ginclude/stdatomic.h
index 9f2475b739d1..a56ba5d96399 100644
--- a/gcc/ginclude/stdatomic.h
+++ b/gcc/ginclude/stdatomic.h
@@ -79,7 +79,9 @@ typedef _Atomic __INTMAX_TYPE__ atomic_intmax_t;
typedef _Atomic __UINTMAX_TYPE__ atomic_uintmax_t;
+#if !(defined __STDC_VERSION__ && __STDC_VERSION__ > 201710L)
#define ATOMIC_VAR_INIT(VALUE) (VALUE)
+#endif
/* Initialize an atomic object pointed to by PTR with VAL. */
#define atomic_init(PTR, VAL) \
diff --git a/gcc/testsuite/gcc.dg/atomic/c2x-stdatomic-var-init-1.c b/gcc/testsuite/gcc.dg/atomic/c2x-stdatomic-var-init-1.c
new file mode 100644
index 000000000000..1978a4103502
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/atomic/c2x-stdatomic-var-init-1.c
@@ -0,0 +1,9 @@
+/* Test ATOMIC_VAR_INIT not in C2x. */
+/* { dg-do compile } */
+/* { dg-options "-std=c2x -pedantic-errors" } */
+
+#include <stdatomic.h>
+
+#ifdef ATOMIC_VAR_INIT
+#error "ATOMIC_VAR_INIT defined"
+#endif
--
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