From 74a04e80c86cfe4b7e138b01fb0a0efd9b1ea5a2 Mon Sep 17 00:00:00 2001
From: Alexey Bataev <a.bataev@hotmail.com>
Date: Wed, 13 Mar 2019 19:31:34 +0000
Subject: [PATCH] [OPENMP]Disable ADL in C for user-defined reductions.

C does not support ADL, disable it for C to prevent compiler crash.

llvm-svn: 356089
---
 clang/lib/Sema/SemaOpenMP.cpp                  | 60 +++++++++++++-------------
 clang/test/OpenMP/declare_reduction_messages.c | 10 +++++
 2 files changed, 41 insertions(+), 29 deletions(-)

diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
index 68ee887..fbbef37 100644
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -10958,35 +10958,37 @@ buildDeclareReductionRef(Sema &SemaRef, SourceLocation Loc, SourceRange Range,
     }
   }
   // Perform ADL.
-  argumentDependentLookup(SemaRef, ReductionId, Loc, Ty, Lookups);
-  if (auto *VD = filterLookupForUDReductionAndMapper<ValueDecl *>(
-          Lookups, [&SemaRef, Ty](ValueDecl *D) -> ValueDecl * {
-            if (!D->isInvalidDecl() &&
-                SemaRef.Context.hasSameType(D->getType(), Ty))
-              return D;
-            return nullptr;
-          }))
-    return SemaRef.BuildDeclRefExpr(VD, VD->getType().getNonReferenceType(),
-                                    VK_LValue, Loc);
-  if (auto *VD = filterLookupForUDReductionAndMapper<ValueDecl *>(
-          Lookups, [&SemaRef, Ty, Loc](ValueDecl *D) -> ValueDecl * {
-            if (!D->isInvalidDecl() &&
-                SemaRef.IsDerivedFrom(Loc, Ty, D->getType()) &&
-                !Ty.isMoreQualifiedThan(D->getType()))
-              return D;
-            return nullptr;
-          })) {
-    CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
-                       /*DetectVirtual=*/false);
-    if (SemaRef.IsDerivedFrom(Loc, Ty, VD->getType(), Paths)) {
-      if (!Paths.isAmbiguous(SemaRef.Context.getCanonicalType(
-              VD->getType().getUnqualifiedType()))) {
-        if (SemaRef.CheckBaseClassAccess(Loc, VD->getType(), Ty, Paths.front(),
-                                         /*DiagID=*/0) !=
-            Sema::AR_inaccessible) {
-          SemaRef.BuildBasePathArray(Paths, BasePath);
-          return SemaRef.BuildDeclRefExpr(
-              VD, VD->getType().getNonReferenceType(), VK_LValue, Loc);
+  if (SemaRef.getLangOpts().CPlusPlus) {
+    argumentDependentLookup(SemaRef, ReductionId, Loc, Ty, Lookups);
+    if (auto *VD = filterLookupForUDReductionAndMapper<ValueDecl *>(
+            Lookups, [&SemaRef, Ty](ValueDecl *D) -> ValueDecl * {
+              if (!D->isInvalidDecl() &&
+                  SemaRef.Context.hasSameType(D->getType(), Ty))
+                return D;
+              return nullptr;
+            }))
+      return SemaRef.BuildDeclRefExpr(VD, VD->getType().getNonReferenceType(),
+                                      VK_LValue, Loc);
+    if (auto *VD = filterLookupForUDReductionAndMapper<ValueDecl *>(
+            Lookups, [&SemaRef, Ty, Loc](ValueDecl *D) -> ValueDecl * {
+              if (!D->isInvalidDecl() &&
+                  SemaRef.IsDerivedFrom(Loc, Ty, D->getType()) &&
+                  !Ty.isMoreQualifiedThan(D->getType()))
+                return D;
+              return nullptr;
+            })) {
+      CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
+                         /*DetectVirtual=*/false);
+      if (SemaRef.IsDerivedFrom(Loc, Ty, VD->getType(), Paths)) {
+        if (!Paths.isAmbiguous(SemaRef.Context.getCanonicalType(
+                VD->getType().getUnqualifiedType()))) {
+          if (SemaRef.CheckBaseClassAccess(
+                  Loc, VD->getType(), Ty, Paths.front(),
+                  /*DiagID=*/0) != Sema::AR_inaccessible) {
+            SemaRef.BuildBasePathArray(Paths, BasePath);
+            return SemaRef.BuildDeclRefExpr(
+                VD, VD->getType().getNonReferenceType(), VK_LValue, Loc);
+          }
         }
       }
     }
diff --git a/clang/test/OpenMP/declare_reduction_messages.c b/clang/test/OpenMP/declare_reduction_messages.c
index 39387c7..27e9e6e 100644
--- a/clang/test/OpenMP/declare_reduction_messages.c
+++ b/clang/test/OpenMP/declare_reduction_messages.c
@@ -41,7 +41,17 @@ int temp; // expected-note 6 {{'temp' declared here}}
 #pragma omp declare reduction(fun8 : long : omp_out += omp_in) initializer(omp_priv = 23)) // expected-warning {{extra tokens at the end of '#pragma omp declare reduction' are ignored}} expected-error {{redefinition of user-defined reduction for type 'long'}}
 #pragma omp declare reduction(fun9 : long : omp_out += omp_in) initializer(omp_priv = )    // expected-error {{expected expression}}
 
+struct S {
+  int s;
+};
+#pragma omp declare reduction(+: struct S: omp_out.s += omp_in.s) // initializer(omp_priv = { .s = 0 })
+
 int fun(int arg) {
+  struct S s;// expected-note {{'s' defined here}}
+  s.s = 0;
+#pragma omp parallel for reduction(+ : s) // expected-error {{list item of type 'struct S' is not valid for specified reduction operation: unable to provide default initialization value}}
+  for (arg = 0; arg < 10; ++arg)
+    s.s += arg;
 #pragma omp declare reduction(red : int : omp_out++)
   {
 #pragma omp declare reduction(red : int : omp_out++) // expected-note {{previous definition is here}}
-- 
2.7.4