From: Alexander Kornienko <alexfh@google.com>
Date: Tue, 12 Nov 2013 17:50:13 +0000 (+0000)
Subject: Remove extra whitespace instead of breaking the line in comments when possible.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=a7462b8ce22a3f754bf51eeeb01adafc42b32cea;p=clang

Remove extra whitespace instead of breaking the line in comments when possible.

Summary: Solves the problem described in http://llvm.org/PR17756

Reviewers: klimek

Reviewed By: klimek

CC: cfe-commits, klimek

Differential Revision: http://llvm-reviews.chandlerc.com/D2131

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@194493 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Format/BreakableToken.cpp b/lib/Format/BreakableToken.cpp
index 97475780f4..d720ce990b 100644
--- a/lib/Format/BreakableToken.cpp
+++ b/lib/Format/BreakableToken.cpp
@@ -215,7 +215,16 @@ void BreakableLineComment::insertBreak(unsigned LineIndex, unsigned TailOffset,
                                        WhitespaceManager &Whitespaces) {
   Whitespaces.replaceWhitespaceInToken(
       Tok, OriginalPrefix.size() + TailOffset + Split.first, Split.second,
-      Postfix, Prefix, InPPDirective, 1, IndentLevel, StartColumn);
+      Postfix, Prefix, InPPDirective, /*Newlines=*/1, IndentLevel, StartColumn);
+}
+
+void BreakableLineComment::replaceWhitespace(unsigned LineIndex,
+                                             unsigned TailOffset, Split Split,
+                                             WhitespaceManager &Whitespaces) {
+  Whitespaces.replaceWhitespaceInToken(
+      Tok, OriginalPrefix.size() + TailOffset + Split.first, Split.second, "",
+      "", /*InPPDirective=*/false, /*Newlines=*/0, /*IndentLevel=*/0,
+      /*Spaces=*/1);
 }
 
 void
@@ -223,7 +232,9 @@ BreakableLineComment::replaceWhitespaceBefore(unsigned LineIndex,
                                               WhitespaceManager &Whitespaces) {
   if (OriginalPrefix != Prefix) {
     Whitespaces.replaceWhitespaceInToken(Tok, OriginalPrefix.size(), 0, "", "",
-                                         false, 0, /*IndentLevel=*/0, 1);
+                                         /*InPPDirective=*/false,
+                                         /*Newlines=*/0, /*IndentLevel=*/0,
+                                         /*Spaces=*/1);
   }
 }
 
@@ -374,6 +385,18 @@ void BreakableBlockComment::insertBreak(unsigned LineIndex, unsigned TailOffset,
       IndentLevel, IndentAtLineBreak - Decoration.size());
 }
 
+void BreakableBlockComment::replaceWhitespace(unsigned LineIndex,
+                                              unsigned TailOffset, Split Split,
+                                              WhitespaceManager &Whitespaces) {
+  StringRef Text = Lines[LineIndex].substr(TailOffset);
+  unsigned BreakOffsetInToken =
+      Text.data() - Tok.TokenText.data() + Split.first;
+  unsigned CharsToRemove = Split.second;
+  Whitespaces.replaceWhitespaceInToken(
+      Tok, BreakOffsetInToken, CharsToRemove, "", "", /*InPPDirective=*/false,
+      /*Newlines=*/0, /*IndentLevel=*/0, /*Spaces=*/1);
+}
+
 void
 BreakableBlockComment::replaceWhitespaceBefore(unsigned LineIndex,
                                                WhitespaceManager &Whitespaces) {
diff --git a/lib/Format/BreakableToken.h b/lib/Format/BreakableToken.h
index 132301c9f6..b965190d54 100644
--- a/lib/Format/BreakableToken.h
+++ b/lib/Format/BreakableToken.h
@@ -61,6 +61,12 @@ public:
   virtual void insertBreak(unsigned LineIndex, unsigned TailOffset, Split Split,
                            WhitespaceManager &Whitespaces) = 0;
 
+  /// \brief Replaces the whitespace range described by \p Split with a single
+  /// space.
+  virtual void replaceWhitespace(unsigned LineIndex, unsigned TailOffset,
+                                 Split Split,
+                                 WhitespaceManager &Whitespaces) = 0;
+
   /// \brief Replaces the whitespace between \p LineIndex-1 and \p LineIndex.
   virtual void replaceWhitespaceBefore(unsigned LineIndex,
                                        WhitespaceManager &Whitespaces) {}
@@ -121,6 +127,9 @@ public:
                          unsigned ColumnLimit) const;
   virtual void insertBreak(unsigned LineIndex, unsigned TailOffset, Split Split,
                            WhitespaceManager &Whitespaces);
+  virtual void replaceWhitespace(unsigned LineIndex, unsigned TailOffset,
+                                 Split Split,
+                                 WhitespaceManager &Whitespaces) {}
 };
 
 class BreakableLineComment : public BreakableSingleLineToken {
@@ -137,6 +146,9 @@ public:
                          unsigned ColumnLimit) const;
   virtual void insertBreak(unsigned LineIndex, unsigned TailOffset, Split Split,
                            WhitespaceManager &Whitespaces);
+  virtual void replaceWhitespace(unsigned LineIndex, unsigned TailOffset,
+                                 Split Split,
+                                 WhitespaceManager &Whitespaces);
   virtual void replaceWhitespaceBefore(unsigned LineIndex,
                                        WhitespaceManager &Whitespaces);
 
@@ -166,6 +178,9 @@ public:
                          unsigned ColumnLimit) const;
   virtual void insertBreak(unsigned LineIndex, unsigned TailOffset, Split Split,
                            WhitespaceManager &Whitespaces);
+  virtual void replaceWhitespace(unsigned LineIndex, unsigned TailOffset,
+                                 Split Split,
+                                 WhitespaceManager &Whitespaces);
   virtual void replaceWhitespaceBefore(unsigned LineIndex,
                                        WhitespaceManager &Whitespaces);
 
diff --git a/lib/Format/ContinuationIndenter.cpp b/lib/Format/ContinuationIndenter.cpp
index 1e10ce3492..971acc2b7a 100644
--- a/lib/Format/ContinuationIndenter.cpp
+++ b/lib/Format/ContinuationIndenter.cpp
@@ -813,6 +813,15 @@ unsigned ContinuationIndenter::breakProtrudingToken(const FormatToken &Current,
       assert(Split.first != 0);
       unsigned NewRemainingTokenColumns = Token->getLineLengthAfterSplit(
           LineIndex, TailOffset + Split.first + Split.second, StringRef::npos);
+
+      // We can remove extra whitespace instead of breaking the line.
+      if (RemainingTokenColumns + 1 - Split.second <= RemainingSpace) {
+        RemainingTokenColumns = 0;
+        if (!DryRun)
+          Token->replaceWhitespace(LineIndex, TailOffset, Split, Whitespaces);
+        break;
+      }
+
       assert(NewRemainingTokenColumns < RemainingTokenColumns);
       if (!DryRun)
         Token->insertBreak(LineIndex, TailOffset, Split, Whitespaces);
diff --git a/unittests/Format/FormatTest.cpp b/unittests/Format/FormatTest.cpp
index 9f05619bb1..f2ac3ba94f 100644
--- a/unittests/Format/FormatTest.cpp
+++ b/unittests/Format/FormatTest.cpp
@@ -985,6 +985,11 @@ TEST_F(FormatTest, SplitsLongCxxComments) {
             format("//Even if it makes the line exceed the column limit",
                    getLLVMStyleWithColumns(51)));
   EXPECT_EQ("//--But not here", format("//--But not here", getLLVMStyle()));
+
+  EXPECT_EQ("// aa bb cc dd",
+            format("// aa bb             cc dd                   ",
+                   getLLVMStyleWithColumns(15)));
+
   EXPECT_EQ("// A comment before\n"
             "// a macro\n"
             "// definition\n"
@@ -1252,6 +1257,17 @@ TEST_F(FormatTest, SplitsLongLinesInComments) {
                    "      \n"
                    "               \n"
                    "      */\n"));
+
+  EXPECT_EQ("/* a a */",
+            format("/* a a            */", getLLVMStyleWithColumns(15)));
+  EXPECT_EQ("/* a a bc  */",
+            format("/* a a            bc  */", getLLVMStyleWithColumns(15)));
+  EXPECT_EQ("/* aaa aaa\n"
+            " * aaaaa */",
+            format("/* aaa aaa aaaaa       */", getLLVMStyleWithColumns(15)));
+  EXPECT_EQ("/* aaa aaa\n"
+            " * aaaaa     */",
+            format("/* aaa aaa aaaaa     */", getLLVMStyleWithColumns(15)));
 }
 
 TEST_F(FormatTest, SplitsLongLinesInCommentsInPreprocessor) {