[ASTMatchers] Let isArrow also support UnresolvedMemberExpr, CXXDependentScopeMemberExpr

[aaron.ballman]

LGTM, with a request for the documentation.

include/clang/ASTMatchers/ASTMatchers.h

4698–4707

Can you update the example to show how this works on the new kinds of member expressions?

[shuaiwang]

Addressed review comment.

docs/LibASTMatchersReference.html

struct Foo {
     Foo(int) : foo_("A") { }
     string foo_;
   };
 cxxConstructorDecl(hasAnyConstructorInitializer(isWritten()))
   will match Foo(int), but not Foo()
 </pre></td></tr>
 
 
+<tr><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1CXXDependentScopeMemberExpr.html">CXXDependentScopeMemberExpr</a>&gt;</td><td class="name" onclick="toggle('isArrow2')"><a name="isArrow2Anchor">isArrow</a></td><td></td></tr>
+<tr><td colspan="4" class="doc" id="isArrow2"><pre>Matches member expressions that are called with '-&gt;' as opposed
+to '.'.
+
+Member calls on the implicit this pointer match as called with '-&gt;'.
+
+Given
+  class Y {
+    void x() { this-&gt;x(); x(); Y y; y.x(); a; this-&gt;b; Y::b; }
+    template &lt;class T&gt; void f() { this-&gt;f&lt;T&gt;(); f&lt;T&gt;(); }
+    int a;
+    static int b;
+  };
+  template &lt;class T&gt;
+  class Z {
+    void x() { this-&gt;m; }
+  };
+memberExpr(isArrow())
+  matches this-&gt;x, x, y.x, a, this-&gt;b
+cxxDependentScopeMemberExpr(isArrow())
+  matches this-&gt;m
+unresolvedMemberExpr(isArrow())
+  matches this-&gt;f&lt;T&gt;, f&lt;T&gt;
+</pre></td></tr>
+
+
 <tr><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1CXXMethodDecl.html">CXXMethodDecl</a>&gt;</td><td class="name" onclick="toggle('isConst0')"><a name="isConst0Anchor">isConst</a></td><td></td></tr>
 <tr><td colspan="4" class="doc" id="isConst0"><pre>Matches if the given method declaration is const.
 
 Given
 struct A {
   void foo() const;
   void bar();
 };

 <tr><td colspan="4" class="doc" id="isArrow0"><pre>Matches member expressions that are called with '-&gt;' as opposed
 to '.'.
 
 Member calls on the implicit this pointer match as called with '-&gt;'.
 
 Given
   class Y {
     void x() { this-&gt;x(); x(); Y y; y.x(); a; this-&gt;b; Y::b; }
+    template &lt;class T&gt; void f() { this-&gt;f&lt;T&gt;(); f&lt;T&gt;(); }
     int a;
     static int b;
   };
+  template &lt;class T&gt;
+  class Z {
+    void x() { this-&gt;m; }
+  };
 memberExpr(isArrow())
   matches this-&gt;x, x, y.x, a, this-&gt;b
+cxxDependentScopeMemberExpr(isArrow())
+  matches this-&gt;m
+unresolvedMemberExpr(isArrow())
+  matches this-&gt;f&lt;T&gt;, f&lt;T&gt;
 </pre></td></tr>
 
 
 <tr><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1NamedDecl.html">NamedDecl</a>&gt;</td><td class="name" onclick="toggle('hasExternalFormalLinkage0')"><a name="hasExternalFormalLinkage0Anchor">hasExternalFormalLinkage</a></td><td></td></tr>
 <tr><td colspan="4" class="doc" id="hasExternalFormalLinkage0"><pre>Matches a declaration that has external formal linkage.
 
 Example matches only z (matcher = varDecl(hasExternalFormalLinkage()))
 void f() {

 <tr><td colspan="4" class="doc" id="hasOperatorName1"><pre>Matches the operator Name of operator expressions (binary or
 unary).
 
 Example matches a || b (matcher = binaryOperator(hasOperatorName("||")))
   !(a || b)
 </pre></td></tr>
 
 
+<tr><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1UnresolvedMemberExpr.html">UnresolvedMemberExpr</a>&gt;</td><td class="name" onclick="toggle('isArrow1')"><a name="isArrow1Anchor">isArrow</a></td><td></td></tr>
+<tr><td colspan="4" class="doc" id="isArrow1"><pre>Matches member expressions that are called with '-&gt;' as opposed
+to '.'.
+
+Member calls on the implicit this pointer match as called with '-&gt;'.
+
+Given
+  class Y {
+    void x() { this-&gt;x(); x(); Y y; y.x(); a; this-&gt;b; Y::b; }
+    template &lt;class T&gt; void f() { this-&gt;f&lt;T&gt;(); f&lt;T&gt;(); }
+    int a;
+    static int b;
+  };
+  template &lt;class T&gt;
+  class Z {
+    void x() { this-&gt;m; }
+  };
+memberExpr(isArrow())
+  matches this-&gt;x, x, y.x, a, this-&gt;b
+cxxDependentScopeMemberExpr(isArrow())
+  matches this-&gt;m
+unresolvedMemberExpr(isArrow())
+  matches this-&gt;f&lt;T&gt;, f&lt;T&gt;
+</pre></td></tr>
+
+
 <tr><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1VarDecl.html">VarDecl</a>&gt;</td><td class="name" onclick="toggle('hasAutomaticStorageDuration0')"><a name="hasAutomaticStorageDuration0Anchor">hasAutomaticStorageDuration</a></td><td></td></tr>
 <tr><td colspan="4" class="doc" id="hasAutomaticStorageDuration0"><pre>Matches a variable declaration that has automatic storage duration.
 
 Example matches x, but not y, z, or a.
 (matcher = varDecl(hasAutomaticStorageDuration())
 void f() {
   int x;
   static int y;

include/clang/ASTMatchers/ASTMatchers.h

 
 /// Matches member expressions that are called with '->' as opposed
 /// to '.'.
 ///
 /// Member calls on the implicit this pointer match as called with '->'.
 ///
 /// Given
 /// \code
 ///   class Y {
 ///     void x() { this->x(); x(); Y y; y.x(); a; this->b; Y::b; }
+///     template <class T> void f() { this->f<T>(); f<T>(); }
 ///     int a;
 ///     static int b;
 ///   };
+///   template <class T>
+///   class Z {
+///     void x() { this->m; }
+///   };
 /// \endcode
 /// memberExpr(isArrow())
 ///   matches this->x, x, y.x, a, this->b
-AST_MATCHER(MemberExpr, isArrow) {
+/// cxxDependentScopeMemberExpr(isArrow())
+///   matches this->m
+/// unresolvedMemberExpr(isArrow())
+///   matches this->f<T>, f<T>
+AST_POLYMORPHIC_MATCHER(
+    isArrow, AST_POLYMORPHIC_SUPPORTED_TYPES(MemberExpr, UnresolvedMemberExpr,
+                                             CXXDependentScopeMemberExpr)) {
   return Node.isArrow();
 }
 
 /// Matches QualType nodes that are of integer type.
 ///
 /// Given
 /// \code
 ///   void a(int);

unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp

 
 TEST(IsArrow, MatchesMemberVariablesViaArrow) {
   EXPECT_TRUE(matches("class Y { void x() { this->y; } int y; };",
                       memberExpr(isArrow())));
   EXPECT_TRUE(matches("class Y { void x() { y; } int y; };",
                       memberExpr(isArrow())));
   EXPECT_TRUE(notMatches("class Y { void x() { (*this).y; } int y; };",
                          memberExpr(isArrow())));
+  EXPECT_TRUE(matches("template <class T> class Y { void x() { this->m; } };",
+                      cxxDependentScopeMemberExpr(isArrow())));
+  EXPECT_TRUE(
+      notMatches("template <class T> class Y { void x() { (*this).m; } };",
+                 cxxDependentScopeMemberExpr(isArrow())));
 }
 
 TEST(IsArrow, MatchesStaticMemberVariablesViaArrow) {
   EXPECT_TRUE(matches("class Y { void x() { this->y; } static int y; };",
                       memberExpr(isArrow())));
   EXPECT_TRUE(notMatches("class Y { void x() { y; } static int y; };",
                          memberExpr(isArrow())));
   EXPECT_TRUE(notMatches("class Y { void x() { (*this).y; } static int y; };",
                          memberExpr(isArrow())));
 }
 
 TEST(IsArrow, MatchesMemberCallsViaArrow) {
   EXPECT_TRUE(matches("class Y { void x() { this->x(); } };",
                       memberExpr(isArrow())));
   EXPECT_TRUE(matches("class Y { void x() { x(); } };",
                       memberExpr(isArrow())));
   EXPECT_TRUE(notMatches("class Y { void x() { Y y; y.x(); } };",
                          memberExpr(isArrow())));
+  EXPECT_TRUE(
+      matches("class Y { template <class T> void x() { this->x<T>(); } };",
+              unresolvedMemberExpr(isArrow())));
+  EXPECT_TRUE(matches("class Y { template <class T> void x() { x<T>(); } };",
+                      unresolvedMemberExpr(isArrow())));
+  EXPECT_TRUE(
+      notMatches("class Y { template <class T> void x() { (*this).x<T>(); } };",
+                 unresolvedMemberExpr(isArrow())));
 }
 
 TEST(ConversionDeclaration, IsExplicit) {
   EXPECT_TRUE(matches("struct S { explicit operator int(); };",
                       cxxConversionDecl(isExplicit())));
   EXPECT_TRUE(notMatches("struct S { operator int(); };",
                          cxxConversionDecl(isExplicit())));
 }

unittests/ASTMatchers/ASTMatchersNodeTest.cpp

 TEST(Finder, DynamicOnlyAcceptsSomeMatchers) {
   MatchFinder Finder;
   EXPECT_TRUE(Finder.addDynamicMatcher(decl(), nullptr));
   EXPECT_TRUE(Finder.addDynamicMatcher(callExpr(), nullptr));
   EXPECT_TRUE(Finder.addDynamicMatcher(constantArrayType(hasSize(42)),
                                        nullptr));
 
   // Do not accept non-toplevel matchers.
-  EXPECT_FALSE(Finder.addDynamicMatcher(isArrow(), nullptr));
+  EXPECT_FALSE(Finder.addDynamicMatcher(isMain(), nullptr));
   EXPECT_FALSE(Finder.addDynamicMatcher(hasName("x"), nullptr));
 }
 
 TEST(Decl, MatchesDeclarations) {
   EXPECT_TRUE(notMatches("", decl(usingDecl())));
   EXPECT_TRUE(matches("namespace x { class X {}; } using x::X;",
                       decl(usingDecl())));
 }

unittests/ASTMatchers/Dynamic/RegistryTest.cpp

TEST_F(RegistryTest, Errors) {
   EXPECT_TRUE(constructMatcher(
       "cxxRecordDecl",
       constructMatcher("allOf",
                        constructMatcher("isDerivedFrom", StringRef("FOO")),
                        constructMatcher("isArrow")),
       Error.get()).isNull());
   EXPECT_EQ("Incorrect type for arg 1. "
             "(Expected = Matcher<CXXRecordDecl>) != "
-            "(Actual = Matcher<CXXRecordDecl>&Matcher<MemberExpr>)",
+            "(Actual = Matcher<CXXRecordDecl>&Matcher"
+            "<MemberExpr|UnresolvedMemberExpr|CXXDependentScopeMemberExpr>)",
             Error->toString());
 }
 
 TEST_F(RegistryTest, Completion) {
   CompVector Comps = getCompletions();
   // Overloaded
   EXPECT_TRUE(hasCompletion(
       Comps, "hasParent(",