clang-format: [JavaScript] Do requoting in a separate pass

The attempt to fix requoting behavior in r280487 after changes to
tooling::Replacements are incomplete. We essentially need to add to
replacements at the same position, one to insert a line break and one to
change the quoting and that's incompatible with the new
tooling::Replacement API, which does not allow for order-dependent
Replacements. To make the order clear, Replacements::merge() has to be
used, but that requires the merged Replacement to actually refer to the
changed text, which is hard to reproduce for the requoting.

This change fixes the behavior by moving the requoting to a completely
separate pass. The added benefit is that no weird ColumnWidth
calculations are necessary anymore and this should just work even if we
implement string literal splitting in the future.

llvm-svn: 280874
diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp
index 625f855..7fea162 100644
--- a/clang/lib/Format/Format.cpp
+++ b/clang/lib/Format/Format.cpp
@@ -792,47 +792,25 @@
 
 namespace {
 
-class Formatter : public TokenAnalyzer {
+class JavaScriptRequoter : public TokenAnalyzer {
 public:
-  Formatter(const Environment &Env, const FormatStyle &Style,
-            bool *IncompleteFormat)
-      : TokenAnalyzer(Env, Style), IncompleteFormat(IncompleteFormat) {}
+  JavaScriptRequoter(const Environment &Env, const FormatStyle &Style)
+      : TokenAnalyzer(Env, Style) {}
 
   tooling::Replacements
   analyze(TokenAnnotator &Annotator,
           SmallVectorImpl<AnnotatedLine *> &AnnotatedLines,
           FormatTokenLexer &Tokens) override {
-    tooling::Replacements RequoteReplaces;
-    deriveLocalStyle(AnnotatedLines);
     AffectedRangeMgr.computeAffectedLines(AnnotatedLines.begin(),
                                           AnnotatedLines.end());
-
-    if (Style.Language == FormatStyle::LK_JavaScript &&
-        Style.JavaScriptQuotes != FormatStyle::JSQS_Leave)
-      requoteJSStringLiteral(AnnotatedLines, RequoteReplaces);
-
-    for (unsigned i = 0, e = AnnotatedLines.size(); i != e; ++i) {
-      Annotator.calculateFormattingInformation(*AnnotatedLines[i]);
-    }
-
-    Annotator.setCommentLineLevels(AnnotatedLines);
-
-    WhitespaceManager Whitespaces(
-        Env.getSourceManager(), Style,
-        inputUsesCRLF(Env.getSourceManager().getBufferData(Env.getFileID())));
-    ContinuationIndenter Indenter(Style, Tokens.getKeywords(),
-                                  Env.getSourceManager(), Whitespaces, Encoding,
-                                  BinPackInconclusiveFunctions);
-    UnwrappedLineFormatter(&Indenter, &Whitespaces, Style, Tokens.getKeywords(),
-                           IncompleteFormat)
-        .format(AnnotatedLines);
-    return RequoteReplaces.merge(Whitespaces.generateReplacements());
+    tooling::Replacements Result;
+    requoteJSStringLiteral(AnnotatedLines, Result);
+    return Result;
   }
 
 private:
-  // If the last token is a double/single-quoted string literal, generates a
-  // replacement with a single/double quoted string literal, re-escaping the
-  // contents in the process.
+  // Replaces double/single-quoted string literal as appropriate, re-escaping
+  // the contents in the process.
   void requoteJSStringLiteral(SmallVectorImpl<AnnotatedLine *> &Lines,
                               tooling::Replacements &Result) {
     for (AnnotatedLine *Line : Lines) {
@@ -844,8 +822,7 @@
         StringRef Input = FormatTok->TokenText;
         if (FormatTok->Finalized || !FormatTok->isStringLiteral() ||
             // NB: testing for not starting with a double quote to avoid
-            // breaking
-            // `template strings`.
+            // breaking `template strings`.
             (Style.JavaScriptQuotes == FormatStyle::JSQS_Single &&
              !Input.startswith("\"")) ||
             (Style.JavaScriptQuotes == FormatStyle::JSQS_Double &&
@@ -870,7 +847,6 @@
                 IsSingle ? "'" : "\"");
 
         // Escape internal quotes.
-        size_t ColumnWidth = FormatTok->TokenText.size();
         bool Escaped = false;
         for (size_t i = 1; i < Input.size() - 1; i++) {
           switch (Input[i]) {
@@ -880,7 +856,6 @@
                  (!IsSingle && Input[i + 1] == '\''))) {
               // Remove this \, it's escaping a " or ' that no longer needs
               // escaping
-              ColumnWidth--;
               Replace(Start.getLocWithOffset(i), 1, "");
               continue;
             }
@@ -891,7 +866,6 @@
             if (!Escaped && IsSingle == (Input[i] == '\'')) {
               // Escape the quote.
               Replace(Start.getLocWithOffset(i), 0, "\\");
-              ColumnWidth++;
             }
             Escaped = false;
             break;
@@ -900,16 +874,46 @@
             break;
           }
         }
-
-        // For formatting, count the number of non-escaped single quotes in them
-        // and adjust ColumnWidth to take the added escapes into account.
-        // FIXME(martinprobst): this might conflict with code breaking a long
-        // string literal (which clang-format doesn't do, yet). For that to
-        // work, this code would have to modify TokenText directly.
-        FormatTok->ColumnWidth = ColumnWidth;
       }
     }
   }
+};
+
+class Formatter : public TokenAnalyzer {
+public:
+  Formatter(const Environment &Env, const FormatStyle &Style,
+            bool *IncompleteFormat)
+      : TokenAnalyzer(Env, Style), IncompleteFormat(IncompleteFormat) {}
+
+  tooling::Replacements
+  analyze(TokenAnnotator &Annotator,
+          SmallVectorImpl<AnnotatedLine *> &AnnotatedLines,
+          FormatTokenLexer &Tokens) override {
+    tooling::Replacements Result;
+    deriveLocalStyle(AnnotatedLines);
+    AffectedRangeMgr.computeAffectedLines(AnnotatedLines.begin(),
+                                          AnnotatedLines.end());
+    for (unsigned i = 0, e = AnnotatedLines.size(); i != e; ++i) {
+      Annotator.calculateFormattingInformation(*AnnotatedLines[i]);
+    }
+    Annotator.setCommentLineLevels(AnnotatedLines);
+
+    WhitespaceManager Whitespaces(
+        Env.getSourceManager(), Style,
+        inputUsesCRLF(Env.getSourceManager().getBufferData(Env.getFileID())));
+    ContinuationIndenter Indenter(Style, Tokens.getKeywords(),
+                                  Env.getSourceManager(), Whitespaces, Encoding,
+                                  BinPackInconclusiveFunctions);
+    UnwrappedLineFormatter(&Indenter, &Whitespaces, Style, Tokens.getKeywords(),
+                           IncompleteFormat)
+        .format(AnnotatedLines);
+    for (const auto &R : Whitespaces.generateReplacements())
+      if (Result.add(R))
+        return Result;
+    return Result;
+  }
+
+private:
 
   static bool inputUsesCRLF(StringRef Text) {
     return Text.count('\r') * 2 > Text.count('\n');
@@ -1691,8 +1695,24 @@
   if (Expanded.DisableFormat)
     return tooling::Replacements();
 
-  std::unique_ptr<Environment> Env =
-      Environment::CreateVirtualEnvironment(Code, FileName, Ranges);
+  auto Env = Environment::CreateVirtualEnvironment(Code, FileName, Ranges);
+
+  if (Style.Language == FormatStyle::LK_JavaScript &&
+      Style.JavaScriptQuotes != FormatStyle::JSQS_Leave) {
+    JavaScriptRequoter Requoter(*Env, Expanded);
+    tooling::Replacements Requotes = Requoter.process();
+    if (!Requotes.empty()) {
+      auto NewCode = applyAllReplacements(Code, Requotes);
+      if (NewCode) {
+        auto NewEnv = Environment::CreateVirtualEnvironment(
+            *NewCode, FileName,
+            tooling::calculateRangesAfterReplacements(Requotes, Ranges));
+        Formatter Format(*NewEnv, Expanded, IncompleteFormat);
+        return Requotes.merge(Format.process());
+      }
+    }
+  }
+
   Formatter Format(*Env, Expanded, IncompleteFormat);
   return Format.process();
 }