[clang][ASTMatchers] Add arrayTypeLoc ast matcher for ArrayTypeLoc

[yuhaouy]

There's arrayType matcher for matching ArrayType, but no matcher for ArrayTypeLoc. This change complements it.

Note that there's already hasElementTypeLoc matcher, which was declared together with the hasElementType matcher.

[llvmbot]

@llvm/pr-subscribers-clang

Author: Yu Hao (yuhaouy)

Changes

There's arrayType matcher for matching ArrayType, but no matcher for ArrayTypeLoc. This change complements it.

Note that there's already hasElementTypeLoc matcher, which was declared together with the hasElementType matcher.

---

Full diff: https://github.com/llvm/llvm-project/pull/168990.diff

3 Files Affected:

• (modified) clang/include/clang/ASTMatchers/ASTMatchers.h (+13)
• (modified) clang/lib/ASTMatchers/ASTMatchersInternal.cpp (+2)
• (modified) clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp (+20)

diff --git a/clang/include/clang/ASTMatchers/ASTMatchers.h b/clang/include/clang/ASTMatchers/ASTMatchers.h
index bca2d8425b3f5..e3ec26207d2bc 100644
--- a/clang/include/clang/ASTMatchers/ASTMatchers.h
+++ b/clang/include/clang/ASTMatchers/ASTMatchers.h
@@ -7003,6 +7003,19 @@ AST_MATCHER_P(ReferenceTypeLoc, hasReferentLoc, internal::Matcher<TypeLoc>,
   return ReferentMatcher.matches(Node.getPointeeLoc(), Finder, Builder);
 }
 
+/// Matches `ArrayTypeLoc`s.
+///
+/// Given
+/// \code
+///   int a[] = {1, 2};
+///   int b[3];
+///   void f() { int c[a[0]]; }
+/// \endcode
+/// arrayTypeLoc()
+///   matches "int a[]", "int b[3]" and "int c[a[0]]".
+extern const internal::VariadicDynCastAllOfMatcher<TypeLoc, ArrayTypeLoc>
+    arrayTypeLoc;
+
 /// Matches template specialization `TypeLoc`s.
 ///
 /// Given
diff --git a/clang/lib/ASTMatchers/ASTMatchersInternal.cpp b/clang/lib/ASTMatchers/ASTMatchersInternal.cpp
index 0874b3d0c45f5..13696a6fc71f2 100644
--- a/clang/lib/ASTMatchers/ASTMatchersInternal.cpp
+++ b/clang/lib/ASTMatchers/ASTMatchersInternal.cpp
@@ -807,6 +807,8 @@ const internal::VariadicDynCastAllOfMatcher<TypeLoc, PointerTypeLoc>
     pointerTypeLoc;
 const internal::VariadicDynCastAllOfMatcher<TypeLoc, ReferenceTypeLoc>
     referenceTypeLoc;
+const internal::VariadicDynCastAllOfMatcher<TypeLoc, ArrayTypeLoc>
+    arrayTypeLoc;
 const internal::VariadicDynCastAllOfMatcher<TypeLoc,
                                             TemplateSpecializationTypeLoc>
     templateSpecializationTypeLoc;
diff --git a/clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp b/clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp
index 3fcb5582d3dd7..108b32e5d91b9 100644
--- a/clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp
+++ b/clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp
@@ -2353,6 +2353,26 @@ TEST_P(ASTMatchersTest, ReferenceTypeLocTest_BindsToAnyRvalueReferenceTypeLoc) {
   EXPECT_TRUE(matches("float&& r = 3.0;", matcher));
 }
 
+TEST_P(ASTMatchersTest, ArrayTypeLocTest_BindsToAnyArrayTypeLoc) {
+  auto matcher = varDecl(hasName("x"), hasTypeLoc(arrayTypeLoc()));
+  EXPECT_TRUE(matches("int x[3];", matcher));
+  EXPECT_TRUE(matches("float x[3];", matcher));
+  EXPECT_TRUE(matches("char x[3];", matcher));
+  EXPECT_TRUE(matches("void* x[3];", matcher));
+  EXPECT_TRUE(matches("const int x[3] = {1, 2, 3};", matcher));
+  EXPECT_TRUE(matches("int x[3][4];", matcher));
+  EXPECT_TRUE(matches("void foo(int x[]);", matcher));
+  EXPECT_TRUE(matches("int a[] = {1, 2}; void foo() {int x[a[0]];}", matcher));
+}
+
+TEST_P(ASTMatchersTest, ArrayTypeLocTest_DoesNotBindToNonArrayTypeLoc) {
+  auto matcher = varDecl(hasName("x"), hasTypeLoc(arrayTypeLoc()));
+  EXPECT_TRUE(notMatches("int x;", matcher));
+  EXPECT_TRUE(notMatches("float x;", matcher));
+  EXPECT_TRUE(notMatches("char x;", matcher));
+  EXPECT_TRUE(notMatches("void* x;", matcher));
+}
+
 TEST_P(ASTMatchersTest,
        TemplateSpecializationTypeLocTest_BindsToVarDeclTemplateSpecialization) {
   if (!GetParam().isCXX()) {

[github-actions]

✅ With the latest revision this PR passed the C/C++ code formatter.

[github-actions]

🐧 Linux x64 Test Results

• 111411 tests passed
• 4434 tests skipped

[AaronBallman]

Please be sure to run clang/docs/tools/dump_ast_matchers.py to regenerate the documentation for the new matcher.

You should also update clang/lib/ASTMatchers/Dynamic/Registry.cpp to add the dynamic matcher at the same time.

And finally, this should come with a release note in clang/docs/ReleaseNotes.rst.

[yuhaouy]

Thanks! Done.