From: Gabor Marton <martongabesz@gmail.com>
Date: Thu, 9 Aug 2018 12:36:25 +0000 (+0000)
Subject: Fix structural inequivalency of forward EnumDecl
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=ff80b2b617bb3ceb96dc5e34208670fefd84686e;p=clang

Fix structural inequivalency of forward EnumDecl

Summary:
Currently we consider one forward declared RecordDecl and another with a
definition equal. We have to do the same in case of enums.

Reviewers: a_sidorin, r.stahl, xazax.hun

Subscribers: rnkovacs, dkrupp, cfe-commits

Differential Revision: https://reviews.llvm.org/D50444

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@339336 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/AST/ASTStructuralEquivalence.cpp b/lib/AST/ASTStructuralEquivalence.cpp
index 7fc3239b03..1a3fb4063b 100644
--- a/lib/AST/ASTStructuralEquivalence.cpp
+++ b/lib/AST/ASTStructuralEquivalence.cpp
@@ -1178,6 +1178,14 @@ static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
 /// Determine structural equivalence of two enums.
 static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
                                      EnumDecl *D1, EnumDecl *D2) {
+
+  // Compare the definitions of these two enums. If either or both are
+  // incomplete (i.e. forward declared), we assume that they are equivalent.
+  D1 = D1->getDefinition();
+  D2 = D2->getDefinition();
+  if (!D1 || !D2)
+    return true;
+
   EnumDecl::enumerator_iterator EC2 = D2->enumerator_begin(),
                                 EC2End = D2->enumerator_end();
   for (EnumDecl::enumerator_iterator EC1 = D1->enumerator_begin(),
diff --git a/unittests/AST/StructuralEquivalenceTest.cpp b/unittests/AST/StructuralEquivalenceTest.cpp
index 41477dd26c..7ff7736d4c 100644
--- a/unittests/AST/StructuralEquivalenceTest.cpp
+++ b/unittests/AST/StructuralEquivalenceTest.cpp
@@ -642,6 +642,32 @@ TEST_F(StructuralEquivalenceRecordTest, TemplateVsNonTemplate) {
   EXPECT_FALSE(testStructuralMatch(t));
 }
 
+TEST_F(StructuralEquivalenceRecordTest,
+    FwdDeclRecordShouldBeEqualWithFwdDeclRecord) {
+  auto t = makeNamedDecls("class foo;", "class foo;", Lang_CXX11);
+  EXPECT_TRUE(testStructuralMatch(t));
+}
+
+TEST_F(StructuralEquivalenceRecordTest,
+       FwdDeclRecordShouldBeEqualWithRecordWhichHasDefinition) {
+  auto t =
+      makeNamedDecls("class foo;", "class foo { int A; };", Lang_CXX11);
+  EXPECT_TRUE(testStructuralMatch(t));
+}
+
+TEST_F(StructuralEquivalenceRecordTest,
+       RecordShouldBeEqualWithRecordWhichHasDefinition) {
+  auto t = makeNamedDecls("class foo { int A; };", "class foo { int A; };",
+                          Lang_CXX11);
+  EXPECT_TRUE(testStructuralMatch(t));
+}
+
+TEST_F(StructuralEquivalenceRecordTest, RecordsWithDifferentBody) {
+  auto t = makeNamedDecls("class foo { int B; };", "class foo { int A; };",
+                          Lang_CXX11);
+  EXPECT_FALSE(testStructuralMatch(t));
+}
+
 TEST_F(StructuralEquivalenceTest, CompareSameDeclWithMultiple) {
   auto t = makeNamedDecls(
       "struct A{ }; struct B{ }; void foo(A a, A b);",
@@ -650,5 +676,33 @@ TEST_F(StructuralEquivalenceTest, CompareSameDeclWithMultiple) {
   EXPECT_FALSE(testStructuralMatch(t));
 }
 
+struct StructuralEquivalenceEnumTest : StructuralEquivalenceTest {};
+
+TEST_F(StructuralEquivalenceEnumTest, FwdDeclEnumShouldBeEqualWithFwdDeclEnum) {
+  auto t = makeNamedDecls("enum class foo;", "enum class foo;", Lang_CXX11);
+  EXPECT_TRUE(testStructuralMatch(t));
+}
+
+TEST_F(StructuralEquivalenceEnumTest,
+       FwdDeclEnumShouldBeEqualWithEnumWhichHasDefinition) {
+  auto t =
+      makeNamedDecls("enum class foo;", "enum class foo { A };", Lang_CXX11);
+  EXPECT_TRUE(testStructuralMatch(t));
+}
+
+TEST_F(StructuralEquivalenceEnumTest,
+       EnumShouldBeEqualWithEnumWhichHasDefinition) {
+  auto t = makeNamedDecls("enum class foo { A };", "enum class foo { A };",
+                          Lang_CXX11);
+  EXPECT_TRUE(testStructuralMatch(t));
+}
+
+TEST_F(StructuralEquivalenceEnumTest, EnumsWithDifferentBody) {
+  auto t = makeNamedDecls("enum class foo { B };", "enum class foo { A };",
+                          Lang_CXX11);
+  EXPECT_FALSE(testStructuralMatch(t));
+}
+
+
 } // end namespace ast_matchers
 } // end namespace clang