[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

2 files changed, 24 insertions, 1 deletions

diff --git a/clang/include/clang/ASTMatchers/ASTMatchers.h b/clang/include/clang/ASTMatchers/ASTMatchers.h
index 75dc654905f..58f65a39fb4 100644
--- a/clang/include/clang/ASTMatchers/ASTMatchers.h
+++ b/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
diff --git a/clang/include/clang/ASTMatchers/ASTMatchersInternal.h b/clang/include/clang/ASTMatchers/ASTMatchersInternal.h
index c5ca6188a22..b0a45789d9c 100644
--- a/clang/include/clang/ASTMatchers/ASTMatchersInternal.h
+++ b/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.