Replace clang::tooling::Replacements with std::set<clang::tooling::Replacement>.

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 9ae3201a4c2b0964141b30d3207de19373c716b6..f48515399cda33e4097e5189289eda563715deaf 100644
--- a/tools/clang/rewrite_to_chrome_style/RewriteToChromeStyle.cpp
+++ b/tools/clang/rewrite_to_chrome_style/RewriteToChromeStyle.cpp
@@ -494,6 +494,25 @@ class RewriterBase : public MatchFinder::MatchCallback {
   explicit RewriterBase(Replacements* replacements)
       : replacements_(replacements) {}
 
+  void addReplacementIfNeeded(const Replacement& new_replacement) {
+    // Ignore the replacement if it is a duplicate.
+    bool is_same_replacement_already_present = std::any_of(
+        replacements_->begin(), replacements_->end(),
+        [&new_replacement](const Replacement& old_replacement) {
+          return new_replacement.toString() == old_replacement.toString();

[Łukasz Anforowicz, 2016/08/16 22:24:16]

Replacement doesn't define ==.  And Replacements doesn't have |contains| or
|find| method.  Therefore - I end up with an ugly std::any_of and with
x.toString() == y.toString().  :-(

+        });
+    if (is_same_replacement_already_present)
+      return;

[Łukasz Anforowicz, 2016/08/16 22:24:16]

If we didn't check |is_same_replacement_already_present|, then the new
|Replacements::add| method would fail saying (in |err.toString()|) something
like:

New replacement:
/usr/local/google/home/lukasza/src/chromium4/src/tools/clang/rewrite_to_chrome_style/tests/methods-actual.cc:
2635:+5:"ptr_"
conflicts with existing replacement:
/usr/local/google/home/lukasza/src/chromium4/src/tools/clang/rewrite_to_chrome_style/tests/methods-actual.cc:
2635:+5:"ptr_"

+
+    // Try to add the replacement
+    if (llvm::Error err = replacements_->add(new_replacement)) {
+      llvm::outs() << "Replacements::add failed: "
+                   << toString(std::move(err)) << "\n";
+      assert(false);  // Order-dependent replacements?
+      return;

[Łukasz Anforowicz, 2016/08/16 22:24:16]

I am not sure how I should spell a fatal failure...

+    }
+  }
+
   void run(const MatchFinder::MatchResult& result) override {
     const DeclNode* decl = result.Nodes.getNodeAs<DeclNode>("decl");
     // If false, there's no name to be renamed.
@@ -523,7 +542,7 @@ class RewriterBase : public MatchFinder::MatchCallback {
         *result.Nodes.getNodeAs<TargetNode>(
             TargetNodeTraits<TargetNode>::GetName()));
     clang::CharSourceRange range = clang::CharSourceRange::getTokenRange(loc);
-    replacements_->emplace(*result.SourceManager, range, new_name);
+    addReplacementIfNeeded(Replacement(*result.SourceManager, range, new_name));
     replacement_names_.emplace(old_name.str(), std::move(new_name));
   }