[clang] 092ac4c - [clang][OpenMP] Don't drop debug location when handing off to OMPIRBuilder. (#219548)

[via cfe-commits]

Author: Abid Qadeer
Date: 2026-09-11T12:37:21+01:00
New Revision: 092ac4c2626af97a09d768a63a32a2b4b96f754c

URL: https://github.com/llvm/llvm-project/commit/092ac4c2626af97a09d768a63a32a2b4b96f754c
DIFF: https://github.com/llvm/llvm-project/commit/092ac4c2626af97a09d768a63a32a2b4b96f754c.diff

LOG: [clang][OpenMP] Don't drop debug location when handing off to OMPIRBuilder. (#219548)

All the clang callsites that hand a `LocationDescription` to the
`OpenMPIRBuilder` pass `CGF.Builder`. That selects
`LocationDescription(const IRBuilderBase &)`, which carries both the
insertion point and the current debug location.

The 2 call sites fixed in this PR used `CGF.Builder.saveIP()` which
passes only an insertion point, selecting `LocationDescription(const
InsertPointTy &)`, which leaves `DL` empty. As a result, the IR the
builder emitted on clang's behalf came out without `!dbg`.

Fixed by passing `CGF.Builder`, as the other callsites do.

---------

Co-authored-by: Cursor <cursoragent at cursor.com>

Added: 
    clang/test/OpenMP/debug-info-ompirbuilder-handoff.c

Modified: 
    clang/lib/CodeGen/CGOpenMPRuntime.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/CodeGen/CGOpenMPRuntime.cpp b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
index 80d20f3259822..1ad07936e6f05 100644
--- a/clang/lib/CodeGen/CGOpenMPRuntime.cpp
+++ b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
@@ -1422,7 +1422,7 @@ llvm::Value *CGOpenMPRuntime::getThreadID(CodeGenFunction &CGF,
   // the clang invariants used below might be broken.
   if (CGM.getLangOpts().OpenMPIRBuilder) {
     SmallString<128> Buffer;
-    OMPBuilder.updateToLocation(CGF.Builder.saveIP());
+    OMPBuilder.updateToLocation(CGF.Builder);
     uint32_t SrcLocStrSize;
     auto *SrcLocStr = OMPBuilder.getOrCreateSrcLocStr(
         getIdentStringFromSourceLocation(CGF, Loc, Buffer), SrcLocStrSize);
@@ -11811,7 +11811,7 @@ void CGOpenMPRuntime::emitTargetDataCalls(
                          CGF.AllocaInsertPt->getIterator());
   InsertPointTy CodeGenIP(CGF.Builder.GetInsertBlock(),
                           CGF.Builder.GetInsertPoint());
-  llvm::OpenMPIRBuilder::LocationDescription OmpLoc(CodeGenIP);
+  llvm::OpenMPIRBuilder::LocationDescription OmpLoc(CGF.Builder);
   llvm::OpenMPIRBuilder::InsertPointTy AfterIP =
       cantFail(OMPBuilder.createTargetData(
           OmpLoc, AllocaIP, CodeGenIP, /*DeallocBlocks=*/{}, DeviceID,

diff  --git a/clang/test/OpenMP/debug-info-ompirbuilder-handoff.c b/clang/test/OpenMP/debug-info-ompirbuilder-handoff.c
new file mode 100644
index 0000000000000..036b04a932bb2
--- /dev/null
+++ b/clang/test/OpenMP/debug-info-ompirbuilder-handoff.c
@@ -0,0 +1,38 @@
+// Check that the debug location clang has established survives the hand-off to
+// the OpenMPIRBuilder, so that the IR the builder emits on clang's behalf still
+// carries a !dbg attachment.
+
+// RUN: %clang_cc1 -fopenmp -fopenmp-enable-irbuilder -triple x86_64-unknown-unknown \
+// RUN:   -fopenmp-targets=x86_64-unknown-linux-gnu -debug-info-kind=limited \
+// RUN:   -emit-llvm %s -o - | FileCheck %s
+
+int cond;
+void use(int);
+
+// CGOpenMPRuntime::getThreadID() defers to the OpenMPIRBuilder when it is
+// enabled, so the thread-num call is emitted by the builder and must inherit
+// the location clang was holding.
+
+// CHECK-LABEL: define {{.*}}@single_region
+// CHECK:       entry:
+// CHECK-NEXT:    call i32 @__kmpc_global_thread_num({{.*}}), !dbg ![[LOC:[0-9]+]]
+// CHECK-NEXT:    call i32 @__kmpc_single({{.*}}), !dbg ![[LOC]]
+void single_region(void) {
+#pragma omp single
+  use(1);
+}
+
+// CGOpenMPRuntime::emitTargetDataCalls() passes the 'if' condition down to
+// OpenMPIRBuilder::createTargetData(), which emits the branch on it. The mapper
+// calls of the region are not useful here because restoreIP() reinstalls a
+// location from the instruction at the insertion point, so they keep their !dbg
+// either way; this branch is emitted before that happens and is the only
+// observable witness on that path.
+
+// CHECK-LABEL: define {{.*}}@target_data_if
+// CHECK:         %[[TOBOOL:.+]] = icmp ne i32 %{{.+}}, 0, !dbg ![[LOC2:[0-9]+]]
+// CHECK-NEXT:    br i1 %[[TOBOOL]], label %{{.+}}, label %{{.+}}, !dbg ![[LOC2]]
+void target_data_if(int *p) {
+#pragma omp target data map(tofrom : p[0 : 4]) if (cond)
+  use(2);
+}