rewrite_to_chrome_style: skip nodes in synthesized functions.

tools/clang/rewrite_to_chrome_style/RewriteToChromeStyle.cpp

Index: tools/clang/rewrite_to_chrome_style/RewriteToChromeStyle.cpp
diff --git a/tools/clang/rewrite_to_chrome_style/RewriteToChromeStyle.cpp b/tools/clang/rewrite_to_chrome_style/RewriteToChromeStyle.cpp
index db208abc2f762e0a7848ddb5f3700cb21743c46f..442df030fd2a498ee77b637e64bbb95c63cf2ee5 100644
--- a/tools/clang/rewrite_to_chrome_style/RewriteToChromeStyle.cpp
+++ b/tools/clang/rewrite_to_chrome_style/RewriteToChromeStyle.cpp
@@ -53,6 +53,12 @@ AST_MATCHER(clang::FunctionDecl, isOverloadedOperator) {
   return Node.isOverloadedOperator();
 }
 
+// This is available in newer clang revisions... but alas, Chrome has not rolled
+// that far yet.
+AST_MATCHER(clang::FunctionDecl, isDefaulted) {
+  return Node.isDefaulted();
+}
+
 constexpr char kBlinkFieldPrefix[] = "m_";
 constexpr char kBlinkStaticMemberPrefix[] = "s_";
 
@@ -210,6 +216,7 @@ struct TargetNodeTraits<clang::CXXCtorInitializer> {
   static constexpr char kName[] = "initializer";
   static clang::CharSourceRange GetRange(
       const clang::CXXCtorInitializer& init) {
+    assert(init.isWritten());
     return clang::CharSourceRange::getTokenRange(init.getSourceLocation());
   }
 };
@@ -390,7 +397,14 @@ int main(int argc, const char* argv[]) {
   //     ...
   //   }
   // matches |x| in if (x).
-  auto member_matcher = id("expr", memberExpr(member(field_decl_matcher)));
+  auto member_matcher =
+      id("expr",
+         // Needed to avoid matching member references in functions synthesized

[danakj, 2016/01/28 23:08:20]

can you put this comment on the unless part?

[dcheng, 2016/01/28 23:15:43]

Done.

+         // by the compiler, such as a synthesized copy constructor.
+         // This skips explicitly defaulted functions as well, but that's OK:
+         // there's nothing interesting to rewrite in those either.
+         memberExpr(member(field_decl_matcher),
+                    unless(hasAncestor(functionDecl(isDefaulted())))));

[danakj, 2016/01/28 23:08:20]

why the ancestor part of this? (maybe add to comment)

[dcheng, 2016/01/28 23:15:43]

Hm... that's kind of implicit in "member references in functions synthesized by
the compiler". Any suggestions on how to improve this wording?

[danakj, 2016/01/29 00:16:55]

oh the ancestor is the function, this is the member? ok got it. maybe just
saying "in functions (which would be the ancestor of this member)
synthesized..." ?

[dcheng, 2016/01/29 01:17:30]

Done.

   auto decl_ref_matcher = id("expr", declRefExpr(to(var_decl_matcher)));
 
   MemberRewriter member_rewriter(&replacements);
@@ -506,7 +520,8 @@ int main(int argc, const char* argv[]) {
   // matches each initializer in the constructor for S.
   auto constructor_initializer_matcher =
       cxxConstructorDecl(forEachConstructorInitializer(
-          id("initializer", cxxCtorInitializer(forField(field_decl_matcher)))));
+          id("initializer",
+             cxxCtorInitializer(forField(field_decl_matcher), isWritten()))));
 
   ConstructorInitializerRewriter constructor_initializer_rewriter(
       &replacements);