[clang] 14d89bf - [ASTMatchers] Fix isDerivedFrom for recursive templates

[Jan Korous via cfe-commits]

Author: Jan Korous
Date: 2020-04-15T12:49:01-07:00
New Revision: 14d89bfbe0b4f633689d829145fc9f0bfdb07b6e

URL: https://github.com/llvm/llvm-project/commit/14d89bfbe0b4f633689d829145fc9f0bfdb07b6e
DIFF: https://github.com/llvm/llvm-project/commit/14d89bfbe0b4f633689d829145fc9f0bfdb07b6e.diff

LOG: [ASTMatchers] Fix isDerivedFrom for recursive templates

Differential Revision: https://reviews.llvm.org/D77612

Added: 
    

Modified: 
    clang/lib/ASTMatchers/ASTMatchFinder.cpp
    clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/ASTMatchers/ASTMatchFinder.cpp b/clang/lib/ASTMatchers/ASTMatchFinder.cpp
index f1e1dae2d6b7..1b49067f0f9d 100644
--- a/clang/lib/ASTMatchers/ASTMatchFinder.cpp
+++ b/clang/lib/ASTMatchers/ASTMatchFinder.cpp
@@ -916,9 +916,8 @@ bool MatchASTVisitor::classIsDerivedFrom(const CXXRecordDecl *Declaration,
     if (!ClassDecl)
       continue;
     if (ClassDecl == Declaration) {
-      // This can happen for recursive template definitions; if the
-      // current declaration did not match, we can safely return false.
-      return false;
+      // This can happen for recursive template definitions.
+      continue;
     }
     BoundNodesTreeBuilder Result(*Builder);
     if (Base.matches(*ClassDecl, this, &Result)) {

diff  --git a/clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp b/clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp
index 428879d0695c..05a77580a7ad 100644
--- a/clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp
+++ b/clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp
@@ -453,6 +453,20 @@ TEST(DeclarationMatcher, ClassIsDerived) {
   EXPECT_TRUE(notMatches("class X;", IsDerivedFromX));
   EXPECT_TRUE(notMatches("class Y;", IsDerivedFromX));
   EXPECT_TRUE(notMatches("", IsDerivedFromX));
+  EXPECT_TRUE(matches("class X {}; template<int N> class Y : Y<N-1>, X {};",
+    IsDerivedFromX));
+  EXPECT_TRUE(matches("class X {}; template<int N> class Y : X, Y<N-1> {};",
+    IsDerivedFromX));
+
+  DeclarationMatcher IsZDerivedFromX = cxxRecordDecl(hasName("Z"),
+    isDerivedFrom("X"));
+  EXPECT_TRUE(
+    matches(
+      "class X {};"
+      "template<int N> class Y : Y<N-1> {};"
+      "template<> class Y<0> : X {};"
+      "class Z : Y<1> {};",
+      IsZDerivedFromX));
 
   DeclarationMatcher IsDirectlyDerivedFromX =
       cxxRecordDecl(isDirectlyDerivedFrom("X"));