[clang] Avoid unevaluated implicit private (PR #92055)

[via cfe-commits]

https://github.com/SunilKuravinakop updated https://github.com/llvm/llvm-project/pull/92055

>From 6946c9f1285d5a27eafcdbf13f79c0641736198d Mon Sep 17 00:00:00 2001
From: Sunil Kuravinakop <kuravina at pe28vega.us.cray.com>
Date: Thu, 9 May 2024 12:09:15 -0500
Subject: [PATCH 1/3] Avoiding DeclRefExpr with "non_odr_use_unevaluated" to
 declare "Implicit Private variable" DeclRefExpr.

  Changes to be committed:
 	modified:   clang/lib/Sema/SemaOpenMP.cpp
---
 clang/lib/Sema/SemaOpenMP.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
index cf5447f223d45..bb6518099b4df 100644
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -3757,7 +3757,8 @@ class DSAAttrChecker final : public StmtVisitor<DSAAttrChecker, void> {
   void VisitDeclRefExpr(DeclRefExpr *E) {
     if (TryCaptureCXXThisMembers || E->isTypeDependent() ||
         E->isValueDependent() || E->containsUnexpandedParameterPack() ||
-        E->isInstantiationDependent())
+        E->isInstantiationDependent() ||
+        E->isNonOdrUse() == clang::NOUR_Unevaluated)
       return;
     if (auto *VD = dyn_cast<VarDecl>(E->getDecl())) {
       // Check the datasharing rules for the expressions in the clauses.

>From 862907f4a6d7cebfb1b816e9ec890c39d0da112e Mon Sep 17 00:00:00 2001
From: Sunil Kuravinakop <kuravina at pe28vega.us.cray.com>
Date: Mon, 13 May 2024 01:28:59 -0500
Subject: [PATCH 2/3] Adding checks for proper declaration of DeclRefExpr under
 the task directive (when variable can be non_odr_use_unevaluated).

  Changes to be committed:
 	modified:   clang/test/OpenMP/task_ast_print.cpp
---
 clang/test/OpenMP/task_ast_print.cpp | 34 ++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/clang/test/OpenMP/task_ast_print.cpp b/clang/test/OpenMP/task_ast_print.cpp
index 12923e6ab4244..9d545c5f6716c 100644
--- a/clang/test/OpenMP/task_ast_print.cpp
+++ b/clang/test/OpenMP/task_ast_print.cpp
@@ -5,6 +5,7 @@
 // RUN: %clang_cc1 -verify -Wno-vla -fopenmp-simd -ast-print %s | FileCheck %s
 // RUN: %clang_cc1 -fopenmp-simd -x c++ -std=c++11 -emit-pch -o %t %s
 // RUN: %clang_cc1 -fopenmp-simd -std=c++11 -include-pch %t -verify -Wno-vla %s -ast-print | FileCheck %s
+// RUN: %clang_cc1 -triple x86_64-pc-linux-gnu -fopenmp -ast-dump  %s | FileCheck %s --check-prefix=DUMP
 // expected-no-diagnostics
 
 #ifndef HEADER
@@ -208,4 +209,37 @@ int main(int argc, char **argv) {
 extern template int S<int>::TS;
 extern template long S<long>::TS;
 
+int
+implicit_firstprivate() {
+
+#pragma omp parallel num_threads(1)
+  {
+    int i = 0;
+    // DUMP : OMPTaskDirective
+    // DUMP-NEXT : OMPFirstprivateClause
+    // DUMP-NEXT : DeclRefExpr {{.+}} 'i' {{.+}} refers_to_enclosing_variable_or_capture
+    #pragma omp task
+    {
+	int j = sizeof(i);
+	j = i;
+    }
+  }
+}
+
+int
+no_implicit_firstprivate() {
+
+#pragma omp parallel num_threads(1)
+  {
+    int i = 0;
+    // DUMP : OMPTaskDirective
+    // DUMP-NEXT : CapturedStmt
+    // DUMP : DeclRefExpr {{.+}} 'i' {{.+}} non_odr_use_unevaluated refers_to_enclosing_variable_or_capture
+    #pragma omp task
+    {
+	int j = sizeof(i);
+    }
+  }
+}
+
 #endif

>From 96c997ad09d87e48af7929b527259c5037242e10 Mon Sep 17 00:00:00 2001
From: Sunil Kuravinakop <kuravina at pe28vega.us.cray.com>
Date: Tue, 14 May 2024 04:47:00 -0500
Subject: [PATCH 3/3] Minor changes to the test case.   Changes to be
 committed:  	modified:   clang/test/OpenMP/task_ast_print.cpp

---
 clang/test/OpenMP/task_ast_print.cpp | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/clang/test/OpenMP/task_ast_print.cpp b/clang/test/OpenMP/task_ast_print.cpp
index 9d545c5f6716c..cb2cc63f63214 100644
--- a/clang/test/OpenMP/task_ast_print.cpp
+++ b/clang/test/OpenMP/task_ast_print.cpp
@@ -209,15 +209,16 @@ int main(int argc, char **argv) {
 extern template int S<int>::TS;
 extern template long S<long>::TS;
 
-int
+// DUMP-LABEL:  FunctionDecl {{.*}} implicit_firstprivate
+void
 implicit_firstprivate() {
 
 #pragma omp parallel num_threads(1)
   {
     int i = 0;
-    // DUMP : OMPTaskDirective
-    // DUMP-NEXT : OMPFirstprivateClause
-    // DUMP-NEXT : DeclRefExpr {{.+}} 'i' {{.+}} refers_to_enclosing_variable_or_capture
+    // DUMP: OMPTaskDirective 
+    // DUMP-NEXT: OMPFirstprivateClause
+    // DUMP-NEXT: DeclRefExpr {{.+}} 'i' {{.+}} refers_to_enclosing_variable_or_capture
     #pragma omp task
     {
 	int j = sizeof(i);
@@ -226,15 +227,16 @@ implicit_firstprivate() {
   }
 }
 
-int
+// DUMP-LABEL:  FunctionDecl {{.*}} no_implicit_firstprivate
+void
 no_implicit_firstprivate() {
 
 #pragma omp parallel num_threads(1)
   {
     int i = 0;
-    // DUMP : OMPTaskDirective
-    // DUMP-NEXT : CapturedStmt
-    // DUMP : DeclRefExpr {{.+}} 'i' {{.+}} non_odr_use_unevaluated refers_to_enclosing_variable_or_capture
+    // DUMP: OMPTaskDirective
+    // DUMP-NEXT: CapturedStmt
+    // DUMP: DeclRefExpr {{.+}} 'i' {{.+}} non_odr_use_unevaluated refers_to_enclosing_variable_or_capture
     #pragma omp task
     {
 	int j = sizeof(i);