r206295 - Fix assertion when breaking string literals with tab characters.

[Alexander Kornienko]

Author: alexfh
Date: Tue Apr 15 09:52:43 2014
New Revision: 206295

URL: http://llvm.org/viewvc/llvm-project?rev=206295&view=rev
Log:
Fix assertion when breaking string literals with tab characters.

Summary: Fixes http://llvm.org/PR19368

Reviewers: djasper, klimek

Reviewed By: klimek

CC: cfe-commits, klimek

Differential Revision: http://reviews.llvm.org/D3379

Modified:
    cfe/trunk/lib/Format/ContinuationIndenter.cpp
    cfe/trunk/unittests/Format/FormatTest.cpp

Modified: cfe/trunk/lib/Format/ContinuationIndenter.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Format/ContinuationIndenter.cpp?rev=206295&r1=206294&r2=206295&view=diff
==============================================================================
--- cfe/trunk/lib/Format/ContinuationIndenter.cpp (original)
+++ cfe/trunk/lib/Format/ContinuationIndenter.cpp Tue Apr 15 09:52:43 2014
@@ -961,6 +961,12 @@ unsigned ContinuationIndenter::breakProt
         break;
       }
 
+      // When breaking before a tab character, it may be moved by a few columns,
+      // but will still be expanded to the next tab stop, so we don't save any
+      // columns.
+      if (NewRemainingTokenColumns == RemainingTokenColumns)
+        break;
+
       assert(NewRemainingTokenColumns < RemainingTokenColumns);
       if (!DryRun)
         Token->insertBreak(LineIndex, TailOffset, Split, Whitespaces);

Modified: cfe/trunk/unittests/Format/FormatTest.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/unittests/Format/FormatTest.cpp?rev=206295&r1=206294&r2=206295&view=diff
==============================================================================
--- cfe/trunk/unittests/Format/FormatTest.cpp (original)
+++ cfe/trunk/unittests/Format/FormatTest.cpp Tue Apr 15 09:52:43 2014
@@ -6366,7 +6366,7 @@ TEST_F(FormatTest, ReformatRegionAdjusts
                    67, 0, getLLVMStyle()));
 }
 
-TEST_F(FormatTest, BreakStringLiterals) {
+TEST_F(FormatTest, BreaksStringLiterals) {
   EXPECT_EQ("\"some text \"\n"
             "\"other\";",
             format("\"some text other\";", getLLVMStyleWithColumns(12)));
@@ -6526,6 +6526,16 @@ TEST_F(FormatTest, BreakStringLiterals)
       format("#define A \"some text other\";", AlignLeft));
 }
 
+TEST_F(FormatTest, BreaksStringLiteralsWithTabs) {
+  EXPECT_EQ(
+      "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+      "(\n"
+      "    \"x\t\");",
+      format("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+             "aaaaaaa("
+             "\"x\t\");"));
+}
+
 TEST_F(FormatTest, BreaksWideAndNSStringLiterals) {
   EXPECT_EQ(
       "u8\"utf8 string \"\n"