[OpenMP] fix endianness dependent definitions in OMP headers for MSVC (#84540)
MSVC does not define __BYTE_ORDER__ making the check for BigEndian
erroneously evaluate to true and breaking the struct definitions in MSVC
compiled builds correspondingly. The fix adds an additional check for
whether __BYTE_ORDER__ is defined by the compiler to fix these.
---------
Co-authored-by: Vadim Paretsky <b-vadipa@microsoft.com>
GitOrigin-RevId: 110141b37813dc48af33de5e1407231e56acdfc5
diff --git a/runtime/src/kmp.h b/runtime/src/kmp.h
index 1fc3177..26dda9e 100644
--- a/runtime/src/kmp.h
+++ b/runtime/src/kmp.h
@@ -2507,7 +2507,7 @@
union {
kmp_uint8 flag; // flag as an unsigned char
struct { // flag as a set of 8 bits
-#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+#if defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
/* Same fields as in the #else branch, but in reverse order */
unsigned all : 1;
unsigned unused : 3;
@@ -2672,7 +2672,7 @@
#endif // BUILD_TIED_TASK_STACK
typedef struct kmp_tasking_flags { /* Total struct must be exactly 32 bits */
-#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+#if defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
/* Same fields as in the #else branch, but in reverse order */
#if OMPX_TASKGRAPH
unsigned reserved31 : 6;
diff --git a/runtime/src/kmp_lock.h b/runtime/src/kmp_lock.h
index e2a0cda..6202f3d 100644
--- a/runtime/src/kmp_lock.h
+++ b/runtime/src/kmp_lock.h
@@ -120,7 +120,8 @@
struct kmp_base_tas_lock {
// KMP_LOCK_FREE(tas) => unlocked; locked: (gtid+1) of owning thread
-#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ && __LP64__
+#if defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__) && \
+ __LP64__
// Flip the ordering of the high and low 32-bit member to be consistent
// with the memory layout of the address in 64-bit big-endian.
kmp_int32 depth_locked; // depth locked, for nested locks only
diff --git a/runtime/test/tasking/bug_nested_proxy_task.c b/runtime/test/tasking/bug_nested_proxy_task.c
index 24fe1f3..9e0b412 100644
--- a/runtime/test/tasking/bug_nested_proxy_task.c
+++ b/runtime/test/tasking/bug_nested_proxy_task.c
@@ -50,7 +50,7 @@
union {
kmp_uint8 flag; // flag as an unsigned char
struct { // flag as a set of 8 bits
-#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+#if defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
unsigned all : 1;
unsigned unused : 3;
unsigned set : 1;
diff --git a/runtime/test/tasking/bug_proxy_task_dep_waiting.c b/runtime/test/tasking/bug_proxy_task_dep_waiting.c
index 688860c..1e86d57 100644
--- a/runtime/test/tasking/bug_proxy_task_dep_waiting.c
+++ b/runtime/test/tasking/bug_proxy_task_dep_waiting.c
@@ -47,7 +47,7 @@
union {
kmp_uint8 flag; // flag as an unsigned char
struct { // flag as a set of 8 bits
-#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+#if defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
unsigned all : 1;
unsigned unused : 3;
unsigned set : 1;
diff --git a/runtime/test/tasking/hidden_helper_task/common.h b/runtime/test/tasking/hidden_helper_task/common.h
index ba57656..68e2b58 100644
--- a/runtime/test/tasking/hidden_helper_task/common.h
+++ b/runtime/test/tasking/hidden_helper_task/common.h
@@ -17,7 +17,7 @@
union {
unsigned char flag;
struct {
-#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+#if defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
unsigned all : 1;
unsigned unused : 3;
unsigned set : 1;
