[clang] 16cabf2 - [ASTMatchers] HasNameMatcher handles `extern "C"`

[Nathan James via cfe-commits]

Author: Nathan James
Date: 2020-02-26T22:07:47Z
New Revision: 16cabf278fc8c14d415e677ce0bc40d46a6de30d

URL: https://github.com/llvm/llvm-project/commit/16cabf278fc8c14d415e677ce0bc40d46a6de30d
DIFF: https://github.com/llvm/llvm-project/commit/16cabf278fc8c14d415e677ce0bc40d46a6de30d.diff

LOG: [ASTMatchers] HasNameMatcher handles `extern "C"`

Summary: Fixes [[ https://bugs.llvm.org/show_bug.cgi?id=42193 | hasName AST matcher is confused by extern "C" in namespace. ]]

Reviewers: klimek, aaron.ballman, gribozavr2

Reviewed By: aaron.ballman

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D75202

Added: 
    

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

Removed: 
    


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diff  --git a/clang/lib/ASTMatchers/ASTMatchersInternal.cpp b/clang/lib/ASTMatchers/ASTMatchersInternal.cpp
index 59c77a167b1f..777400f84974 100644
--- a/clang/lib/ASTMatchers/ASTMatchersInternal.cpp
+++ b/clang/lib/ASTMatchers/ASTMatchersInternal.cpp
@@ -513,7 +513,13 @@ bool HasNameMatcher::matchesNodeFullFast(const NamedDecl &Node) const {
   if (Ctx->isFunctionOrMethod())
     return Patterns.foundMatch(/*AllowFullyQualified=*/false);
 
-  for (; Ctx && isa<NamedDecl>(Ctx); Ctx = Ctx->getParent()) {
+  for (; Ctx; Ctx = Ctx->getParent()) {
+    // Linkage Spec can just be ignored
+    // FIXME: Any other DeclContext kinds that can be safely disregarded
+    if (isa<LinkageSpecDecl>(Ctx))
+      continue;
+    if (!isa<NamedDecl>(Ctx))
+      break;
     if (Patterns.foundMatch(/*AllowFullyQualified=*/false))
       return true;
 

diff  --git a/clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp b/clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp
index 4b9fce9e3107..65fb11caa489 100644
--- a/clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp
+++ b/clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp
@@ -1643,6 +1643,21 @@ TEST(Matcher, HasNameSupportsFunctionScope) {
   EXPECT_TRUE(matches(code, fieldDecl(hasName("::a::F(int)::S::m"))));
 }
 
+TEST(Matcher, HasNameQualifiedSupportsLinkage) {
+  // https://bugs.llvm.org/show_bug.cgi?id=42193
+  std::string code = R"cpp(namespace foo { extern "C" void test(); })cpp";
+  EXPECT_TRUE(matches(code, functionDecl(hasName("test"))));
+  EXPECT_TRUE(matches(code, functionDecl(hasName("foo::test"))));
+  EXPECT_TRUE(matches(code, functionDecl(hasName("::foo::test"))));
+  EXPECT_TRUE(notMatches(code, functionDecl(hasName("::test"))));
+
+  code = R"cpp(namespace foo { extern "C" { void test(); } })cpp";
+  EXPECT_TRUE(matches(code, functionDecl(hasName("test"))));
+  EXPECT_TRUE(matches(code, functionDecl(hasName("foo::test"))));
+  EXPECT_TRUE(matches(code, functionDecl(hasName("::foo::test"))));
+  EXPECT_TRUE(notMatches(code, functionDecl(hasName("::test"))));
+}
+
 TEST(Matcher, HasAnyName) {
   const std::string Code = "namespace a { namespace b { class C; } }";