Unbreak <stdatomic.h> on ARM + Clang.

Clang only supports atomic operations for ARMv6. For non-ARMv6, we still
need to emit these functions.

Clang's prototype for these functions slightly differs, as it is truly
based on GCC's documentation. It requires the use of signed types, but
also requires varargs. Still, we are not allowed to simply implement
this function directly. Cleverly work around this by implementing it
under a different name and using __strong_reference().

17 files changed, 34 insertions, 17 deletions

diff --git a/lib/libcompiler_rt/Makefile b/lib/libcompiler_rt/Makefile
index 2e869cc..c75ae07 100644
--- a/lib/libcompiler_rt/Makefile
+++ b/lib/libcompiler_rt/Makefile
@@ -156,9 +156,8 @@ SRCF+=	divsi3 \
 	umodsi3
 .endif
 
-# FreeBSD-specific atomic intrinsics. Clang provides them as a builtin.
-.if (${MACHINE_CPUARCH} == "arm" && ${COMPILER_TYPE} != "clang") || \
-    ${MACHINE_CPUARCH} == "mips"
+# FreeBSD-specific atomic intrinsics.
+.if ${MACHINE_CPUARCH} == "arm" || ${MACHINE_CPUARCH} == "mips"
 SRCF+=	__sync_fetch_and_add_4 \
 	__sync_fetch_and_and_4 \
 	__sync_fetch_and_or_4 \
diff --git a/lib/libcompiler_rt/__sync_fetch_and_add_4.c b/lib/libcompiler_rt/__sync_fetch_and_add_4.c
index 3c11a3b..6126cfa 100644
--- a/lib/libcompiler_rt/__sync_fetch_and_add_4.c
+++ b/lib/libcompiler_rt/__sync_fetch_and_add_4.c
@@ -1,6 +1,6 @@
 /* $FreeBSD$ */
 #define	NAME		__sync_fetch_and_add_4
-#define	TYPE		uint32_t
+#define	TYPE		int32_t
 #define	FETCHADD(x, y)	atomic_fetchadd_32(x, y)
 
 #include "__sync_fetch_and_op_n.h"
diff --git a/lib/libcompiler_rt/__sync_fetch_and_add_8.c b/lib/libcompiler_rt/__sync_fetch_and_add_8.c
index 6157c15..2738d5d 100644
--- a/lib/libcompiler_rt/__sync_fetch_and_add_8.c
+++ b/lib/libcompiler_rt/__sync_fetch_and_add_8.c
@@ -1,6 +1,6 @@
 /* $FreeBSD$ */
 #define	NAME		__sync_fetch_and_add_8
-#define	TYPE		uint64_t
+#define	TYPE		int64_t
 #define	FETCHADD(x, y)	atomic_fetchadd_64(x, y)
 
 #include "__sync_fetch_and_op_n.h"
diff --git a/lib/libcompiler_rt/__sync_fetch_and_and_4.c b/lib/libcompiler_rt/__sync_fetch_and_and_4.c
index 1a488ec..49fab80 100644
--- a/lib/libcompiler_rt/__sync_fetch_and_and_4.c
+++ b/lib/libcompiler_rt/__sync_fetch_and_and_4.c
@@ -1,6 +1,6 @@
 /* $FreeBSD$ */
 #define	NAME		__sync_fetch_and_and_4
-#define	TYPE		uint32_t
+#define	TYPE		int32_t
 #define	CMPSET		atomic_cmpset_32
 #define	EXPRESSION	t & value
 
diff --git a/lib/libcompiler_rt/__sync_fetch_and_and_8.c b/lib/libcompiler_rt/__sync_fetch_and_and_8.c
index 9923e31..f681785 100644
--- a/lib/libcompiler_rt/__sync_fetch_and_and_8.c
+++ b/lib/libcompiler_rt/__sync_fetch_and_and_8.c
@@ -1,6 +1,6 @@
 /* $FreeBSD$ */
 #define	NAME		__sync_fetch_and_and_8
-#define	TYPE		uint64_t
+#define	TYPE		int64_t
 #define	CMPSET		atomic_cmpset_64
 #define	EXPRESSION	t & value
 
diff --git a/lib/libcompiler_rt/__sync_fetch_and_op_n.h b/lib/libcompiler_rt/__sync_fetch_and_op_n.h
index f7f0e06..994e271 100644
--- a/lib/libcompiler_rt/__sync_fetch_and_op_n.h
+++ b/lib/libcompiler_rt/__sync_fetch_and_op_n.h
@@ -30,8 +30,13 @@ __FBSDID("$FreeBSD$");
 #include <sys/types.h>
 #include <machine/atomic.h>
 
+#if defined __clang__
+static TYPE
+atomic_func(volatile TYPE *ptr, TYPE value, ...)
+#else
 TYPE
 NAME(volatile TYPE *ptr, TYPE value)
+#endif
 {
 	TYPE t;
 
@@ -45,3 +50,7 @@ NAME(volatile TYPE *ptr, TYPE value)
 
 	return (t);
 }
+
+#ifdef __clang__
+__strong_reference(atomic_func, NAME);
+#endif
diff --git a/lib/libcompiler_rt/__sync_fetch_and_or_4.c b/lib/libcompiler_rt/__sync_fetch_and_or_4.c
index 1feeeb1..879b9ae 100644
--- a/lib/libcompiler_rt/__sync_fetch_and_or_4.c
+++ b/lib/libcompiler_rt/__sync_fetch_and_or_4.c
@@ -1,6 +1,6 @@
 /* $FreeBSD$ */
 #define	NAME		__sync_fetch_and_or_4
-#define	TYPE		uint32_t
+#define	TYPE		int32_t
 #define	CMPSET		atomic_cmpset_32
 #define	EXPRESSION	t | value
 
diff --git a/lib/libcompiler_rt/__sync_fetch_and_or_8.c b/lib/libcompiler_rt/__sync_fetch_and_or_8.c
index 7cb9403..c88a37b 100644
--- a/lib/libcompiler_rt/__sync_fetch_and_or_8.c
+++ b/lib/libcompiler_rt/__sync_fetch_and_or_8.c
@@ -1,6 +1,6 @@
 /* $FreeBSD$ */
 #define	NAME		__sync_fetch_and_or_8
-#define	TYPE		uint64_t
+#define	TYPE		int64_t
 #define	CMPSET		atomic_cmpset_64
 #define	EXPRESSION	t | value
 
diff --git a/lib/libcompiler_rt/__sync_fetch_and_sub_4.c b/lib/libcompiler_rt/__sync_fetch_and_sub_4.c
index a251add..e0fe14c 100644
--- a/lib/libcompiler_rt/__sync_fetch_and_sub_4.c
+++ b/lib/libcompiler_rt/__sync_fetch_and_sub_4.c
@@ -1,6 +1,6 @@
 /* $FreeBSD$ */
 #define	NAME		__sync_fetch_and_sub_4
-#define	TYPE		uint32_t
+#define	TYPE		int32_t
 #define	FETCHADD(x, y)	atomic_fetchadd_32(x, -(y))
 
 #include "__sync_fetch_and_op_n.h"
diff --git a/lib/libcompiler_rt/__sync_fetch_and_sub_8.c b/lib/libcompiler_rt/__sync_fetch_and_sub_8.c
index 5a93f97..4f239b3 100644
--- a/lib/libcompiler_rt/__sync_fetch_and_sub_8.c
+++ b/lib/libcompiler_rt/__sync_fetch_and_sub_8.c
@@ -1,6 +1,6 @@
 /* $FreeBSD$ */
 #define	NAME		__sync_fetch_and_sub_8
-#define	TYPE		uint64_t
+#define	TYPE		int64_t
 #define	FETCHADD(x, y)	atomic_fetchadd_64(x, -(y))
 
 #include "__sync_fetch_and_op_n.h"
diff --git a/lib/libcompiler_rt/__sync_fetch_and_xor_4.c b/lib/libcompiler_rt/__sync_fetch_and_xor_4.c
index d5f732d..8a6aec6 100644
--- a/lib/libcompiler_rt/__sync_fetch_and_xor_4.c
+++ b/lib/libcompiler_rt/__sync_fetch_and_xor_4.c
@@ -1,6 +1,6 @@
 /* $FreeBSD$ */
 #define	NAME		__sync_fetch_and_xor_4
-#define	TYPE		uint32_t
+#define	TYPE		int32_t
 #define	CMPSET		atomic_cmpset_32
 #define	EXPRESSION	t ^ value
 
diff --git a/lib/libcompiler_rt/__sync_fetch_and_xor_8.c b/lib/libcompiler_rt/__sync_fetch_and_xor_8.c
index 610037e..be677f57 100644
--- a/lib/libcompiler_rt/__sync_fetch_and_xor_8.c
+++ b/lib/libcompiler_rt/__sync_fetch_and_xor_8.c
@@ -1,6 +1,6 @@
 /* $FreeBSD$ */
 #define	NAME		__sync_fetch_and_xor_8
-#define	TYPE		uint64_t
+#define	TYPE		int64_t
 #define	CMPSET		atomic_cmpset_64
 #define	EXPRESSION	t ^ value
 
diff --git a/lib/libcompiler_rt/__sync_lock_test_and_set_4.c b/lib/libcompiler_rt/__sync_lock_test_and_set_4.c
index d4965f9..73d1bab 100644
--- a/lib/libcompiler_rt/__sync_lock_test_and_set_4.c
+++ b/lib/libcompiler_rt/__sync_lock_test_and_set_4.c
@@ -1,6 +1,6 @@
 /* $FreeBSD$ */
 #define	NAME		__sync_lock_test_and_set_4
-#define	TYPE		uint32_t
+#define	TYPE		int32_t
 #define	CMPSET		atomic_cmpset_32
 #define	EXPRESSION	value
 
diff --git a/lib/libcompiler_rt/__sync_lock_test_and_set_8.c b/lib/libcompiler_rt/__sync_lock_test_and_set_8.c
index 1e02203..83c1a6a 100644
--- a/lib/libcompiler_rt/__sync_lock_test_and_set_8.c
+++ b/lib/libcompiler_rt/__sync_lock_test_and_set_8.c
@@ -1,6 +1,6 @@
 /* $FreeBSD$ */
 #define	NAME		__sync_lock_test_and_set_8
-#define	TYPE		uint64_t
+#define	TYPE		int64_t
 #define	CMPSET		atomic_cmpset_64
 #define	EXPRESSION	value
 
diff --git a/lib/libcompiler_rt/__sync_val_compare_and_swap_4.c b/lib/libcompiler_rt/__sync_val_compare_and_swap_4.c
index e0ab115..d69b6f5 100644
--- a/lib/libcompiler_rt/__sync_val_compare_and_swap_4.c
+++ b/lib/libcompiler_rt/__sync_val_compare_and_swap_4.c
@@ -1,6 +1,6 @@
 /* $FreeBSD$ */
 #define	NAME		__sync_val_compare_and_swap_4
-#define	TYPE		uint32_t
+#define	TYPE		int32_t
 #define	CMPSET		atomic_cmpset_32
 
 #include "__sync_val_compare_and_swap_n.h"
diff --git a/lib/libcompiler_rt/__sync_val_compare_and_swap_8.c b/lib/libcompiler_rt/__sync_val_compare_and_swap_8.c
index c6f1101..6b7a17d 100644
--- a/lib/libcompiler_rt/__sync_val_compare_and_swap_8.c
+++ b/lib/libcompiler_rt/__sync_val_compare_and_swap_8.c
@@ -1,6 +1,6 @@
 /* $FreeBSD$ */
 #define	NAME		__sync_val_compare_and_swap_8
-#define	TYPE		uint64_t
+#define	TYPE		int64_t
 #define	CMPSET		atomic_cmpset_64
 
 #include "__sync_val_compare_and_swap_n.h"
diff --git a/lib/libcompiler_rt/__sync_val_compare_and_swap_n.h b/lib/libcompiler_rt/__sync_val_compare_and_swap_n.h
index cd4c9a3..ee9d025 100644
--- a/lib/libcompiler_rt/__sync_val_compare_and_swap_n.h
+++ b/lib/libcompiler_rt/__sync_val_compare_and_swap_n.h
@@ -30,8 +30,13 @@ __FBSDID("$FreeBSD$");
 #include <sys/types.h>
 #include <machine/atomic.h>
 
+#if defined __clang__
+static TYPE
+atomic_func(volatile TYPE *ptr, TYPE oldval, TYPE newval, ...)
+#else
 TYPE
 NAME(volatile TYPE *ptr, TYPE oldval, TYPE newval)
+#endif
 {
 	TYPE t;
 
@@ -43,3 +48,7 @@ NAME(volatile TYPE *ptr, TYPE oldval, TYPE newval)
 
 	return (oldval);
 }
+
+#ifdef __clang__
+__strong_reference(atomic_func, NAME);
+#endif