[clang] [OpenMP][Clang] Enable inscan modifier for generic datatypes (PR #82220)

[Animesh Kumar via cfe-commits]

https://github.com/animeshk-amd updated https://github.com/llvm/llvm-project/pull/82220

>From b891329e49972c15941f2d15408ff32cfe3995f3 Mon Sep 17 00:00:00 2001
From: Animesh Kumar <animesh.kumar at amd.com>
Date: Mon, 19 Feb 2024 00:28:39 -0600
Subject: [PATCH] [OpenMP][Clang] Enable inscan modifier for generic datatypes

This patch fixes the #67002 ([OpenMP][Clang] Scan Directive not
supported for Generic types). It disables the Sema checks/analysis
that are run on the helper arrays which go into the implementation
of the `omp scan` directive until the template instantiation
happens.
---
 clang/lib/Sema/SemaOpenMP.cpp        |  3 ++-
 clang/test/OpenMP/scan_ast_print.cpp | 18 ++++++++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
index 7f75cfc5b54f35..f4364a259ad57f 100644
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -4962,7 +4962,8 @@ StmtResult Sema::ActOnOpenMPRegionEnd(StmtResult S,
           if (RC->getModifier() != OMPC_REDUCTION_inscan)
             continue;
           for (Expr *E : RC->copy_array_temps())
-            MarkDeclarationsReferencedInExpr(E);
+            if (E)
+              MarkDeclarationsReferencedInExpr(E);
         }
         if (auto *AC = dyn_cast<OMPAlignedClause>(C)) {
           for (Expr *E : AC->varlists())
diff --git a/clang/test/OpenMP/scan_ast_print.cpp b/clang/test/OpenMP/scan_ast_print.cpp
index 3bbd3b60c3e8c4..82cb13eb6e70f7 100644
--- a/clang/test/OpenMP/scan_ast_print.cpp
+++ b/clang/test/OpenMP/scan_ast_print.cpp
@@ -17,6 +17,10 @@ T tmain(T argc) {
   static T a;
 #pragma omp for reduction(inscan, +: a)
   for (int i = 0; i < 10; ++i) {
+#pragma omp scan inclusive(a)
+  }
+#pragma omp parallel for reduction(inscan, +:a)
+  for (int i = 0; i < 10; ++i) {
 #pragma omp scan inclusive(a)
   }
   return a + argc;
@@ -25,15 +29,29 @@ T tmain(T argc) {
 // CHECK-NEXT: #pragma omp for reduction(inscan, +: a)
 // CHECK-NEXT: for (int i = 0; i < 10; ++i) {
 // CHECK-NEXT: #pragma omp scan inclusive(a){{$}}
+
+// CHECK: #pragma omp parallel for reduction(inscan, +: a)
+// CHECK-NEXT: for (int i = 0; i < 10; ++i) {
+// CHECK-NEXT: #pragma omp scan inclusive(a){{$}}
+
 // CHECK:      static int a;
 // CHECK-NEXT: #pragma omp for reduction(inscan, +: a)
 // CHECK-NEXT: for (int i = 0; i < 10; ++i) {
 // CHECK-NEXT: #pragma omp scan inclusive(a)
+
+// CHECK: #pragma omp parallel for reduction(inscan, +: a)
+// CHECK-NEXT: for (int i = 0; i < 10; ++i) {
+// CHECK-NEXT: #pragma omp scan inclusive(a)
+
 // CHECK:      static char a;
 // CHECK-NEXT: #pragma omp for reduction(inscan, +: a)
 // CHECK-NEXT: for (int i = 0; i < 10; ++i) {
 // CHECK-NEXT: #pragma omp scan inclusive(a)
 
+// CHECK: #pragma omp parallel for reduction(inscan, +: a)
+// CHECK-NEXT: for (int i = 0; i < 10; ++i) {
+// CHECK-NEXT: #pragma omp scan inclusive(a)
+
 int main(int argc, char **argv) {
   static int a;
 // CHECK: static int a;