[ASTMatchers] Introduce a matcher for ObjCIvarExpr, support getting it's declaration.

ObjCIvarExpr is *not* a subclass of MemberExpr, and a separate matcher
is required to support it.
Adding a hasDeclaration support as well, as it's not very useful without
it.

Differential Revision: https://reviews.llvm.org/D49701

llvm-svn: 338137

clang/docs/LibASTMatchersReference.html

@@ -1267,6 +1267,20 @@ Example matches @finally
 </pre></td></tr>
 
 
+<tr><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1Stmt.html">Stmt</a>&gt;</td><td class="name" onclick="toggle('objcIvarRefExpr0')"><a name="objcIvarRefExpr0Anchor">objcIvarRefExpr</a></td><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1ObjCIvarRefExpr.html">ObjCIvarRefExpr</a>&gt;...</td></tr>
+<tr><td colspan="4" class="doc" id="objcIvarRefExpr0"><pre>Matches a reference to an ObjCIvar.
+
+Example: matches "a" in "init" method:
+@implementation A {
+  NSString *a;
+}
+- (void) init {
+  a = @"hello";
+}
+}
+</pre></td></tr>
+
+
 <tr><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1Stmt.html">Stmt</a>&gt;</td><td class="name" onclick="toggle('objcMessageExpr0')"><a name="objcMessageExpr0Anchor">objcMessageExpr</a></td><td>Matcher&lt;<a href="http://clang.llvm.org/doxygen/classclang_1_1ObjCMessageExpr.html">ObjCMessageExpr</a>&gt;...</td></tr>
 <tr><td colspan="4" class="doc" id="objcMessageExpr0"><pre>Matches ObjectiveC Message invocation expressions.
 
@@ -4251,6 +4265,7 @@ The associated declaration is:
 - for MemberExpr, the declaration of the referenced member
 - for CXXConstructExpr, the declaration of the constructor
 - for CXXNewExpr, the declaration of the operator new
+- for ObjCIvarExpr, the declaration of the ivar
 
 For type nodes, hasDeclaration will generally match the declaration of the
 sugared type. Given
@@ -4547,6 +4562,7 @@ The associated declaration is:
 - for MemberExpr, the declaration of the referenced member
 - for CXXConstructExpr, the declaration of the constructor
 - for CXXNewExpr, the declaration of the operator new
+- for ObjCIvarExpr, the declaration of the ivar
 
 For type nodes, hasDeclaration will generally match the declaration of the
 sugared type. Given
@@ -4750,6 +4766,7 @@ The associated declaration is:
 - for MemberExpr, the declaration of the referenced member
 - for CXXConstructExpr, the declaration of the constructor
 - for CXXNewExpr, the declaration of the operator new
+- for ObjCIvarExpr, the declaration of the ivar
 
 For type nodes, hasDeclaration will generally match the declaration of the
 sugared type. Given
@@ -4900,6 +4917,7 @@ The associated declaration is:
 - for MemberExpr, the declaration of the referenced member
 - for CXXConstructExpr, the declaration of the constructor
 - for CXXNewExpr, the declaration of the operator new
+- for ObjCIvarExpr, the declaration of the ivar
 
 For type nodes, hasDeclaration will generally match the declaration of the
 sugared type. Given
@@ -5061,6 +5079,7 @@ The associated declaration is:
 - for MemberExpr, the declaration of the referenced member
 - for CXXConstructExpr, the declaration of the constructor
 - for CXXNewExpr, the declaration of the operator new
+- for ObjCIvarExpr, the declaration of the ivar
 
 For type nodes, hasDeclaration will generally match the declaration of the
 sugared type. Given
@@ -5247,6 +5266,7 @@ The associated declaration is:
 - for MemberExpr, the declaration of the referenced member
 - for CXXConstructExpr, the declaration of the constructor
 - for CXXNewExpr, the declaration of the operator new
+- for ObjCIvarExpr, the declaration of the ivar
 
 For type nodes, hasDeclaration will generally match the declaration of the
 sugared type. Given
@@ -5667,6 +5687,7 @@ The associated declaration is:
 - for MemberExpr, the declaration of the referenced member
 - for CXXConstructExpr, the declaration of the constructor
 - for CXXNewExpr, the declaration of the operator new
+- for ObjCIvarExpr, the declaration of the ivar
 
 For type nodes, hasDeclaration will generally match the declaration of the
 sugared type. Given
@@ -5700,6 +5721,7 @@ The associated declaration is:
 - for MemberExpr, the declaration of the referenced member
 - for CXXConstructExpr, the declaration of the constructor
 - for CXXNewExpr, the declaration of the operator new
+- for ObjCIvarExpr, the declaration of the ivar
 
 For type nodes, hasDeclaration will generally match the declaration of the
 sugared type. Given
@@ -5733,6 +5755,7 @@ The associated declaration is:
 - for MemberExpr, the declaration of the referenced member
 - for CXXConstructExpr, the declaration of the constructor
 - for CXXNewExpr, the declaration of the operator new
+- for ObjCIvarExpr, the declaration of the ivar
 
 For type nodes, hasDeclaration will generally match the declaration of the
 sugared type. Given
@@ -6093,6 +6116,7 @@ The associated declaration is:
 - for MemberExpr, the declaration of the referenced member
 - for CXXConstructExpr, the declaration of the constructor
 - for CXXNewExpr, the declaration of the operator new
+- for ObjCIvarExpr, the declaration of the ivar
 
 For type nodes, hasDeclaration will generally match the declaration of the
 sugared type. Given
@@ -6174,6 +6198,7 @@ The associated declaration is:
 - for MemberExpr, the declaration of the referenced member
 - for CXXConstructExpr, the declaration of the constructor
 - for CXXNewExpr, the declaration of the operator new
+- for ObjCIvarExpr, the declaration of the ivar
 
 For type nodes, hasDeclaration will generally match the declaration of the
 sugared type. Given
@@ -6326,6 +6351,7 @@ The associated declaration is:
 - for MemberExpr, the declaration of the referenced member
 - for CXXConstructExpr, the declaration of the constructor
 - for CXXNewExpr, the declaration of the operator new
+- for ObjCIvarExpr, the declaration of the ivar
 
 For type nodes, hasDeclaration will generally match the declaration of the
 sugared type. Given
@@ -6448,6 +6474,7 @@ The associated declaration is:
 - for MemberExpr, the declaration of the referenced member
 - for CXXConstructExpr, the declaration of the constructor
 - for CXXNewExpr, the declaration of the operator new
+- for ObjCIvarExpr, the declaration of the ivar
 
 For type nodes, hasDeclaration will generally match the declaration of the
 sugared type. Given
@@ -6501,6 +6528,7 @@ The associated declaration is:
 - for MemberExpr, the declaration of the referenced member
 - for CXXConstructExpr, the declaration of the constructor
 - for CXXNewExpr, the declaration of the operator new
+- for ObjCIvarExpr, the declaration of the ivar
 
 For type nodes, hasDeclaration will generally match the declaration of the
 sugared type. Given
@@ -6565,6 +6593,7 @@ The associated declaration is:
 - for MemberExpr, the declaration of the referenced member
 - for CXXConstructExpr, the declaration of the constructor
 - for CXXNewExpr, the declaration of the operator new
+- for ObjCIvarExpr, the declaration of the ivar
 
 For type nodes, hasDeclaration will generally match the declaration of the
 sugared type. Given
@@ -6629,6 +6658,7 @@ The associated declaration is:
 - for MemberExpr, the declaration of the referenced member
 - for CXXConstructExpr, the declaration of the constructor
 - for CXXNewExpr, the declaration of the operator new
+- for ObjCIvarExpr, the declaration of the ivar
 
 For type nodes, hasDeclaration will generally match the declaration of the
 sugared type. Given

clang/include/clang/ASTMatchers/ASTMatchers.h

@@ -1644,6 +1644,21 @@ extern const internal::VariadicDynCastAllOfMatcher<Stmt, Expr> expr;
 extern const internal::VariadicDynCastAllOfMatcher<Stmt, DeclRefExpr>
     declRefExpr;
 
+/// Matches a reference to an ObjCIvar.
+///
+/// Example: matches "a" in "init" method:
+/// \code
+/// @implementation A {
+///   NSString *a;
+/// }
+/// - (void) init {
+///   a = @"hello";
+/// }
+//}
+/// \endcode
+extern const internal::VariadicDynCastAllOfMatcher<Stmt, ObjCIvarRefExpr>
+    objcIvarRefExpr;
+
 /// Matches if statements.
 ///
 /// Example matches 'if (x) {}'
@@ -2655,6 +2670,7 @@ extern const internal::VariadicOperatorMatcherFunc<1, 1> unless;
 /// - for MemberExpr, the declaration of the referenced member
 /// - for CXXConstructExpr, the declaration of the constructor
 /// - for CXXNewExpr, the declaration of the operator new
+/// - for ObjCIvarExpr, the declaration of the ivar
 ///
 /// For type nodes, hasDeclaration will generally match the declaration of the
 /// sugared type. Given

clang/include/clang/ASTMatchers/ASTMatchersInternal.h

@@ -42,6 +42,7 @@
 #include "clang/AST/DeclTemplate.h"
 #include "clang/AST/Expr.h"
 #include "clang/AST/ExprCXX.h"
+#include "clang/AST/ExprObjC.h"
 #include "clang/AST/NestedNameSpecifier.h"
 #include "clang/AST/Stmt.h"
 #include "clang/AST/TemplateName.h"
@@ -865,6 +866,12 @@ private:
     return matchesDecl(Node.getConstructor(), Finder, Builder);
   }
 
+  bool matchesSpecialized(const ObjCIvarRefExpr &Node,
+                          ASTMatchFinder *Finder,
+                          BoundNodesTreeBuilder *Builder) const {
+    return matchesDecl(Node.getDecl(), Finder, Builder);
+  }
+
   /// Extracts the operator new of the new call and returns whether the
   /// inner matcher matches on it.
   bool matchesSpecialized(const CXXNewExpr &Node,
@@ -1110,7 +1117,7 @@ using HasDeclarationSupportedTypes =
              ElaboratedType, InjectedClassNameType, LabelStmt, AddrLabelExpr,
              MemberExpr, QualType, RecordType, TagType,
              TemplateSpecializationType, TemplateTypeParmType, TypedefType,
-             UnresolvedUsingType>;
+             UnresolvedUsingType, ObjCIvarRefExpr>;
 
 /// Converts a \c Matcher<T> to a matcher of desired type \c To by
 /// "adapting" a \c To into a \c T.

clang/lib/ASTMatchers/ASTMatchersInternal.cpp

@@ -679,6 +679,7 @@ const internal::VariadicDynCastAllOfMatcher<Stmt, CXXOperatorCallExpr>
     cxxOperatorCallExpr;
 const internal::VariadicDynCastAllOfMatcher<Stmt, Expr> expr;
 const internal::VariadicDynCastAllOfMatcher<Stmt, DeclRefExpr> declRefExpr;
+const internal::VariadicDynCastAllOfMatcher<Stmt, ObjCIvarRefExpr> objcIvarRefExpr;
 const internal::VariadicDynCastAllOfMatcher<Stmt, IfStmt> ifStmt;
 const internal::VariadicDynCastAllOfMatcher<Stmt, ForStmt> forStmt;
 const internal::VariadicDynCastAllOfMatcher<Stmt, CXXForRangeStmt>

clang/lib/ASTMatchers/Dynamic/Registry.cpp

@@ -410,6 +410,7 @@ RegistryMaps::RegistryMaps() {
   REGISTER_MATCHER(objcImplementationDecl);
   REGISTER_MATCHER(objcInterfaceDecl);
   REGISTER_MATCHER(objcIvarDecl);
+  REGISTER_MATCHER(objcIvarRefExpr);
   REGISTER_MATCHER(objcMessageExpr);
   REGISTER_MATCHER(objcMethodDecl);
   REGISTER_MATCHER(objcObjectPointerType);

clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp

@@ -1354,6 +1354,16 @@ TEST(Matcher, HandlesNullQualTypes) {
       ))))));
 }
 
+TEST(ObjCIvarRefExprMatcher, IvarExpr) {
+  std::string ObjCString =
+    "@interface A @end "
+    "@implementation A { A *x; } - (void) func { x = 0; } @end";
+  EXPECT_TRUE(matchesObjC(ObjCString, objcIvarRefExpr()));
+  EXPECT_TRUE(matchesObjC(ObjCString, objcIvarRefExpr(
+        hasDeclaration(namedDecl(hasName("x"))))));
+  EXPECT_FALSE(matchesObjC(ObjCString, objcIvarRefExpr(
+        hasDeclaration(namedDecl(hasName("y"))))));
+}
 
 TEST(StatementCountIs, FindsNoStatementsInAnEmptyCompoundStatement) {
   EXPECT_TRUE(matches("void f() { }",