clang-format: fix a crash in comment wraps.
Summary:
Previously, clang-format would crash if it tried to wrap an overlong
single line comment, because two parts of the code inserted a break in
the same location.
/** heregoesalongcommentwithnospace */
This wasn't previously noticed as it could only trigger for an overlong
single line comment that did have no breaking opportunities except for a
whitespace at the very beginning.
This also introduces a check for JavaScript to not ever wrap a comment
before an opening curly brace:
/** @mods {donotbreakbeforethecurly} */
This is because some machinery parsing these tags sometimes supports
breaks before a possible `{`, but in some other cases does not.
Previously clang-format was careful never to wrap a line with certain
tags on it. The better solution is to specifically disable wrapping
before the problematic token: this allows wrapping and aligning comments
but still avoids the problem.
Reviewers: krasimir
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D50177
llvm-svn: 338706
diff --git a/clang/lib/Format/BreakableToken.cpp b/clang/lib/Format/BreakableToken.cpp
index fc2f891..300e3f8 100644
--- a/clang/lib/Format/BreakableToken.cpp
+++ b/clang/lib/Format/BreakableToken.cpp
@@ -67,10 +67,11 @@
unsigned ContentStartColumn,
unsigned ColumnLimit,
unsigned TabWidth,
- encoding::Encoding Encoding) {
- LLVM_DEBUG(llvm::dbgs() << "Comment split: \"" << Text << ", " << ColumnLimit
- << "\", Content start: " << ContentStartColumn
- << "\n");
+ encoding::Encoding Encoding,
+ const FormatStyle &Style) {
+ LLVM_DEBUG(llvm::dbgs() << "Comment split: \"" << Text
+ << "\", Column limit: " << ColumnLimit
+ << ", Content start: " << ContentStartColumn << "\n");
if (ColumnLimit <= ContentStartColumn + 1)
return BreakableToken::Split(StringRef::npos, 0);
@@ -95,6 +96,13 @@
if (SpaceOffset != StringRef::npos &&
kNumberedListRegexp->match(Text.substr(SpaceOffset).ltrim(Blanks)))
SpaceOffset = Text.find_last_of(Blanks, SpaceOffset);
+ // In JavaScript, some @tags can be followed by {, and machinery that parses
+ // these comments will fail to understand the comment if followed by a line
+ // break. So avoid ever breaking before a {.
+ if (Style.Language == FormatStyle::LK_JavaScript &&
+ SpaceOffset != StringRef::npos && SpaceOffset + 1 < Text.size() &&
+ Text[SpaceOffset + 1] == '{')
+ SpaceOffset = Text.find_last_of(Blanks, SpaceOffset);
if (SpaceOffset == StringRef::npos ||
// Don't break at leading whitespace.
@@ -109,6 +117,12 @@
Blanks, std::max<unsigned>(MaxSplitBytes, FirstNonWhitespace));
}
if (SpaceOffset != StringRef::npos && SpaceOffset != 0) {
+ // adaptStartOfLine will break after lines starting with /** if the comment
+ // is broken anywhere. Avoid emitting this break twice here.
+ // Example: in /** longtextcomesherethatbreaks */ (with ColumnLimit 20) will
+ // insert a break after /**, so this code must not insert the same break.
+ if (SpaceOffset == 1 && Text[SpaceOffset - 1] == '*')
+ return BreakableToken::Split(StringRef::npos, 0);
StringRef BeforeCut = Text.substr(0, SpaceOffset).rtrim(Blanks);
StringRef AfterCut = Text.substr(SpaceOffset).ltrim(Blanks);
return BreakableToken::Split(BeforeCut.size(),
@@ -260,7 +274,7 @@
return Split(StringRef::npos, 0);
return getCommentSplit(Content[LineIndex].substr(TailOffset),
ContentStartColumn, ColumnLimit, Style.TabWidth,
- Encoding);
+ Encoding, Style);
}
void BreakableComment::compressWhitespace(
@@ -620,6 +634,8 @@
if (DelimitersOnNewline) {
// Since we're breaking at index 1 below, the break position and the
// break length are the same.
+ // Note: this works because getCommentSplit is careful never to split at
+ // the beginning of a line.
size_t BreakLength = Lines[0].substr(1).find_first_not_of(Blanks);
if (BreakLength != StringRef::npos)
insertBreak(LineIndex, 0, Split(1, BreakLength), /*ContentIndent=*/0,