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

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@206295 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Format/ContinuationIndenter.cpp b/lib/Format/ContinuationIndenter.cpp
index 35dc182a2d1e08609c613082b9ccbb254678dc00..9311ca481c344729ec80faa05ed49f56e8a16594 100644 (file)
--- a/lib/Format/ContinuationIndenter.cpp
+++ b/lib/Format/ContinuationIndenter.cpp
@@ -961,6 +961,12 @@ unsigned ContinuationIndenter::breakProtrudingToken(const FormatToken &Current,
         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);

diff --git a/unittests/Format/FormatTest.cpp b/unittests/Format/FormatTest.cpp
index 708ddfa09136875a0d2d31a9c32c3ba2650365f3..f1442e03b6897ab9261b626b942811453d9ec776 100644 (file)
--- a/unittests/Format/FormatTest.cpp
+++ b/unittests/Format/FormatTest.cpp
@@ -6366,7 +6366,7 @@ TEST_F(FormatTest, ReformatRegionAdjustsIndent) {
                    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"