[clang-format] Fix comment levels between '} else {' and PPDirective.

Summary:
This fixes a regression exposed by r307795 and rL308725 in which the level of a
comment line between '} else {' and a preprocessor directive is incorrectly set
as the level of the '} else {' line. For example, this :
```
int f(int i) {
  if (i) {
    ++i;
  } else {
    // comment
#ifdef A
    --i;
#endif
  }
}
```
was formatted as:
```
int f(int i) {
  if (i) {
    ++i;
  } else {
  // comment
#ifdef A
    --i;
#endif
  }
}
```

Reviewers: djasper, klimek

Reviewed By: klimek

Subscribers: klimek, cfe-commits

Differential Revision: https://reviews.llvm.org/D35794

llvm-svn: 308882

1 files changed, 11 insertions, 7 deletions

diff --git a/clang/lib/Format/UnwrappedLineParser.cpp b/clang/lib/Format/UnwrappedLineParser.cpp
index 4858e596ca4..427dfd57254 100644
--- a/clang/lib/Format/UnwrappedLineParser.cpp
+++ b/clang/lib/Format/UnwrappedLineParser.cpp
@@ -460,7 +460,7 @@ void UnwrappedLineParser::parseBlock(bool MustBeDeclaration, bool AddLevel,
   FormatTok->BlockKind = BK_Block;
 
   unsigned InitialLevel = Line->Level;
-  nextToken();
+  nextToken(/*LevelDifference=*/AddLevel ? 1 : 0);
 
   if (MacroBlock && FormatTok->is(tok::l_paren))
     parseParens();
@@ -486,9 +486,8 @@ void UnwrappedLineParser::parseBlock(bool MustBeDeclaration, bool AddLevel,
     return;
   }
 
-  flushComments(isOnNewLine(*FormatTok));
-  Line->Level = InitialLevel;
-  nextToken(); // Munch the closing brace.
+  // Munch the closing brace.
+  nextToken(/*LevelDifference=*/AddLevel ? -1 : 0);
 
   if (MacroBlock && FormatTok->is(tok::l_paren))
     parseParens();
@@ -496,6 +495,7 @@ void UnwrappedLineParser::parseBlock(bool MustBeDeclaration, bool AddLevel,
   if (MunchSemi && FormatTok->Tok.is(tok::semi))
     nextToken();
   Line->MatchingOpeningBlockLineIndex = OpeningLineIndex;
+  Line->Level = InitialLevel;
   if (OpeningLineIndex != UnwrappedLine::kInvalidIndex) {
     // Update the opening line to add the forward reference as well
     (*CurrentLines)[OpeningLineIndex].MatchingOpeningBlockLineIndex =
@@ -2288,13 +2288,13 @@ void UnwrappedLineParser::flushComments(bool NewlineBeforeNext) {
   CommentsBeforeNextToken.clear();
 }
 
-void UnwrappedLineParser::nextToken() {
+void UnwrappedLineParser::nextToken(int LevelDifference) {
   if (eof())
     return;
   flushComments(isOnNewLine(*FormatTok));
   pushToken(FormatTok);
   if (Style.Language != FormatStyle::LK_JavaScript)
-    readToken();
+    readToken(LevelDifference);
   else
     readTokenWithJavaScriptASI();
 }
@@ -2363,7 +2363,7 @@ void UnwrappedLineParser::distributeComments(
   }
 }
 
-void UnwrappedLineParser::readToken() {
+void UnwrappedLineParser::readToken(int LevelDifference) {
   SmallVector<FormatToken *, 1> Comments;
   do {
     FormatTok = Tokens->getNextToken();
@@ -2376,6 +2376,10 @@ void UnwrappedLineParser::readToken() {
       // directives only after that unwrapped line was finished later.
       bool SwitchToPreprocessorLines = !Line->Tokens.empty();
       ScopedLineState BlockState(*this, SwitchToPreprocessorLines);
+      assert((LevelDifference >= 0 ||
+              static_cast<unsigned>(-LevelDifference) <= Line->Level) &&
+             "LevelDifference makes Line->Level negative");
+      Line->Level += LevelDifference;
       // Comments stored before the preprocessor directive need to be output
       // before the preprocessor directive, at the same level as the
       // preprocessor directive, as we consider them to apply to the directive.