r338706 - clang-format: fix a crash in comment wraps.
Martin Probst via cfe-commits
cfe-commits at lists.llvm.org
Thu Aug 2 04:52:08 PDT 2018
Author: mprobst
Date: Thu Aug 2 04:52:08 2018
New Revision: 338706
URL: http://llvm.org/viewvc/llvm-project?rev=338706&view=rev
Log:
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
Modified:
cfe/trunk/lib/Format/BreakableToken.cpp
cfe/trunk/unittests/Format/FormatTestComments.cpp
cfe/trunk/unittests/Format/FormatTestJS.cpp
Modified: cfe/trunk/lib/Format/BreakableToken.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Format/BreakableToken.cpp?rev=338706&r1=338705&r2=338706&view=diff
==============================================================================
--- cfe/trunk/lib/Format/BreakableToken.cpp (original)
+++ cfe/trunk/lib/Format/BreakableToken.cpp Thu Aug 2 04:52:08 2018
@@ -67,10 +67,11 @@ static BreakableToken::Split getCommentS
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 @@ static BreakableToken::Split getCommentS
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 @@ static BreakableToken::Split getCommentS
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 @@ BreakableComment::getSplit(unsigned Line
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 @@ void BreakableBlockComment::adaptStartOf
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,
Modified: cfe/trunk/unittests/Format/FormatTestComments.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/unittests/Format/FormatTestComments.cpp?rev=338706&r1=338705&r2=338706&view=diff
==============================================================================
--- cfe/trunk/unittests/Format/FormatTestComments.cpp (original)
+++ cfe/trunk/unittests/Format/FormatTestComments.cpp Thu Aug 2 04:52:08 2018
@@ -1254,6 +1254,12 @@ TEST_F(FormatTestComments, SplitsLongLin
" */",
getLLVMStyleWithColumns(20)));
+ // This reproduces a crashing bug where both adaptStartOfLine and
+ // getCommentSplit were trying to wrap after the "/**".
+ EXPECT_EQ("/** multilineblockcommentwithnowrapopportunity */",
+ format("/** multilineblockcommentwithnowrapopportunity */",
+ getLLVMStyleWithColumns(20)));
+
EXPECT_EQ("/*\n"
"\n"
"\n"
Modified: cfe/trunk/unittests/Format/FormatTestJS.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/unittests/Format/FormatTestJS.cpp?rev=338706&r1=338705&r2=338706&view=diff
==============================================================================
--- cfe/trunk/unittests/Format/FormatTestJS.cpp (original)
+++ cfe/trunk/unittests/Format/FormatTestJS.cpp Thu Aug 2 04:52:08 2018
@@ -191,31 +191,32 @@ TEST_F(FormatTestJS, JSDocComments) {
// Break a single line long jsdoc comment pragma.
EXPECT_EQ("/**\n"
- " * @returns\n"
- " * {string}\n"
- " * jsdoc line 12\n"
+ " * @returns {string} jsdoc line 12\n"
" */",
format("/** @returns {string} jsdoc line 12 */",
getGoogleJSStyleWithColumns(20)));
-
EXPECT_EQ("/**\n"
- " * @returns\n"
- " * {string}\n"
+ " * @returns {string}\n"
" * jsdoc line 12\n"
" */",
+ format("/** @returns {string} jsdoc line 12 */",
+ getGoogleJSStyleWithColumns(25)));
+
+ EXPECT_EQ("/**\n"
+ " * @returns {string} jsdoc line 12\n"
+ " */",
format("/** @returns {string} jsdoc line 12 */",
getGoogleJSStyleWithColumns(20)));
// FIXME: this overcounts the */ as a continuation of the 12 when breaking.
// Related to the FIXME in BreakableBlockComment::getRangeLength.
EXPECT_EQ("/**\n"
- " * @returns\n"
- " * {string}\n"
- " * jsdoc line\n"
+ " * @returns {string}\n"
+ " * jsdoc line line\n"
" * 12\n"
" */",
- format("/** @returns {string} jsdoc line 12*/",
- getGoogleJSStyleWithColumns(20)));
+ format("/** @returns {string} jsdoc line line 12*/",
+ getGoogleJSStyleWithColumns(25)));
// Fix a multiline jsdoc comment ending in a comment pragma.
EXPECT_EQ("/**\n"
@@ -2038,27 +2039,32 @@ TEST_F(FormatTestJS, WrapAfterParen) {
TEST_F(FormatTestJS, JSDocAnnotations) {
verifyFormat("/**\n"
- " * @exports\n"
- " * {this.is.a.long.path.to.a.Type}\n"
+ " * @exports {this.is.a.long.path.to.a.Type}\n"
" */",
"/**\n"
" * @exports {this.is.a.long.path.to.a.Type}\n"
" */",
getGoogleJSStyleWithColumns(20));
verifyFormat("/**\n"
- " * @mods\n"
- " * {this.is.a.long.path.to.a.Type}\n"
+ " * @mods {this.is.a.long.path.to.a.Type}\n"
+ " */",
+ "/**\n"
+ " * @mods {this.is.a.long.path.to.a.Type}\n"
+ " */",
+ getGoogleJSStyleWithColumns(20));
+ verifyFormat("/**\n"
+ " * @mods {this.is.a.long.path.to.a.Type}\n"
" */",
"/**\n"
" * @mods {this.is.a.long.path.to.a.Type}\n"
" */",
getGoogleJSStyleWithColumns(20));
verifyFormat("/**\n"
- " * @param\n"
- " * {this.is.a.long.path.to.a.Type}\n"
+ " * @param {canWrap\n"
+ " * onSpace}\n"
" */",
"/**\n"
- " * @param {this.is.a.long.path.to.a.Type}\n"
+ " * @param {canWrap onSpace}\n"
" */",
getGoogleJSStyleWithColumns(20));
verifyFormat("/**\n"
@@ -2083,8 +2089,7 @@ TEST_F(FormatTestJS, JSDocAnnotations) {
" /**\n"
" * long long long\n"
" * long\n"
- " * @param\n"
- " * {this.is.a.long.path.to.a.Type}\n"
+ " * @param {this.is.a.long.path.to.a.Type}\n"
" * a\n"
" * long long long\n"
" * long long\n"
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