[gcc/devel/omp/gcc-12] Add caveat/safeguard to OpenMP: Handle descriptors in target's firstprivate [PR104949]

[gcc/devel/omp/gcc-12] Add caveat/safeguard to OpenMP: Handle descriptors in target's firstprivate [PR104949]

[Thomas Schwinge]

https://gcc.gnu.org/g:5bb50fb4e8fd10b4f6180e756380161c1ffd8a3e

commit 5bb50fb4e8fd10b4f6180e756380161c1ffd8a3e
Author: Thomas Schwinge <thomas@codesourcery.com>
Date:   Thu Mar 23 12:32:35 2023 +0100

    Add caveat/safeguard to OpenMP: Handle descriptors in target's firstprivate [PR104949]
    
    Follow-up to commit 49d1a2f91325fa8cc011149e27e5093a988b3a49
    "OpenMP: Handle descriptors in target's firstprivate [PR104949]".
    
            PR fortran/104949
            libgomp/
            * target.c (gomp_map_vars_internal) <GOMP_MAP_FIRSTPRIVATE>: Add
            caveat/safeguard.
    
    (cherry picked from commit e8fec6998b656dac02d4bc6c69b35a0fb5611e87)

Diff:
---
 libgomp/ChangeLog.omp | 7 +++++++
 libgomp/target.c      | 5 +++++
 2 files changed, 12 insertions(+)

diff --git a/libgomp/ChangeLog.omp b/libgomp/ChangeLog.omp
index fb352b39a6d..63d1f563d5d 100644
--- a/libgomp/ChangeLog.omp
+++ b/libgomp/ChangeLog.omp
@@ -1,5 +1,12 @@
 2023-03-24  Thomas Schwinge  <thomas@codesourcery.com>
 
+	Backported from master:
+	2023-03-24  Thomas Schwinge  <thomas@codesourcery.com>
+
+	PR fortran/104949
+	* target.c (gomp_map_vars_internal) <GOMP_MAP_FIRSTPRIVATE>: Add
+	caveat/safeguard.
+
 	* target.c (gomp_target_rev): Instead of 'dev_to_host_cpy',
 	'host_to_dev_cpy', 'token', take a single 'goacc_asyncqueue'.
 	* libgomp.h (gomp_target_rev): Adjust.
diff --git a/libgomp/target.c b/libgomp/target.c
index 2f53f056e53..de3facb6428 100644
--- a/libgomp/target.c
+++ b/libgomp/target.c
@@ -1482,6 +1482,11 @@ gomp_map_vars_internal (struct gomp_device_descr *devicep,
 		  {
 		    uintptr_t target = (uintptr_t) hostaddrs[i];
 		    void *devptr = *(void**) hostaddrs[i+1] + sizes[i+1];
+		    /* Per
+		       <https://inbox.sourceware.org/gcc-patches/87o7pe12ke.fsf@euler.schwinge.homeip.net>
+		       "OpenMP: Handle descriptors in target's firstprivate [PR104949]"
+		       this probably needs revision for 'aq' usage.  */
+		    assert (!aq);
 		    gomp_copy_host2dev (devicep, aq, devptr, &target,
 					sizeof (void *), false, cbufp);
 		    ++i;