Adding an AST matcher to ignore parenthesis in *types* (rather than...

Adding an AST matcher to ignore parenthesis in *types* (rather than expressions). This is required for traversing certain types (like function pointer types).

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@271927 91177308-0d34-0410-b5e6-96231b3b80d8

docs/LibASTMatchersReference.html

@@ -3521,6 +3521,10 @@ Example matches X, Y
 ChildT must be an AST base type.
 
 Usable as: Any Matcher
+Note that has is direct matcher, so it also matches things like implicit
+casts and paren casts. If you are matching with expr then you should
+probably consider using ignoringParenImpCasts like:
+has(ignoringParenImpCasts(expr())).
 </pre></td></tr>
 
 
@@ -4897,6 +4901,17 @@ Usable as: Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1CallE
 </pre></td></tr>
 
 
+<tr><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1QualType.html">QualType</a>&gt;</td><td class="name" onclick="toggle('ignoringParens0')"><a name="ignoringParens0Anchor">ignoringParens</a></td><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1QualType.html">QualType</a>&gt; InnerMatcher</td></tr>
+<tr><td colspan="4" class="doc" id="ignoringParens0"><pre>Matches types that match InnerMatcher after any parens are stripped.
+
+Given
+  void (*fp)(void);
+The matcher
+  varDecl(hasType(pointerType(pointee(ignoringParens(functionType())))))
+would match the declaration for fp.
+</pre></td></tr>
+
+
 <tr><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1QualType.html">QualType</a>&gt;</td><td class="name" onclick="toggle('pointsTo1')"><a name="pointsTo1Anchor">pointsTo</a></td><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1Decl.html">Decl</a>&gt; InnerMatcher</td></tr>
 <tr><td colspan="4" class="doc" id="pointsTo1"><pre>Overloaded to match the pointee type's declaration.
 </pre></td></tr>

include/clang/ASTMatchers/ASTMatchers.h

@@ -625,6 +625,22 @@ AST_MATCHER_P(Expr, ignoringParenImpCasts,
   return InnerMatcher.matches(*Node.IgnoreParenImpCasts(), Finder, Builder);
 }
 
+/// \brief Matches types that match InnerMatcher after any parens are stripped.
+///
+/// Given
+/// \code
+///   void (*fp)(void);
+/// \endcode
+/// The matcher
+/// \code
+///   varDecl(hasType(pointerType(pointee(ignoringParens(functionType())))))
+/// \endcode
+/// would match the declaration for fp.
+AST_MATCHER_P(QualType, ignoringParens,
+              internal::Matcher<QualType>, InnerMatcher) {
+  return InnerMatcher.matches(Node.IgnoreParens(), Finder, Builder);
+}
+
 /// \brief Matches classTemplateSpecializations where the n'th TemplateArgument
 /// matches the given InnerMatcher.
 ///

lib/ASTMatchers/Dynamic/Registry.cpp

@@ -268,6 +268,7 @@ RegistryMaps::RegistryMaps() {
   REGISTER_MATCHER(ignoringImpCasts);
   REGISTER_MATCHER(ignoringParenCasts);
   REGISTER_MATCHER(ignoringParenImpCasts);
+  REGISTER_MATCHER(ignoringParens);
   REGISTER_MATCHER(implicitCastExpr);
   REGISTER_MATCHER(implicitValueInitExpr);
   REGISTER_MATCHER(incompleteArrayType);

unittests/ASTMatchers/ASTMatchersNodeTest.cpp

@@ -1165,6 +1165,13 @@ TEST(TypeMatching, MatchesFunctionTypes) {
   EXPECT_TRUE(matches("void f(int i) {}", functionType()));
 }
 
+TEST(TypeMatching, IgnoringParens) {
+  EXPECT_TRUE(
+      notMatches("void (*fp)(void);", pointerType(pointee(functionType()))));
+  EXPECT_TRUE(matches("void (*fp)(void);",
+                      pointerType(pointee(ignoringParens(functionType())))));
+}
+
 TEST(TypeMatching, MatchesFunctionProtoTypes) {
   EXPECT_TRUE(matches("int (*f)(int);", functionProtoType()));
   EXPECT_TRUE(matches("void f(int i);", functionProtoType()));