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[clang-tidy] performance-unnecessary-copy-initialization: Do not remove comments on new lines. 

When deleting the copy assignment statement because copied variable is not used
only remove trailing comments on the same line.

Differential Revision: https://reviews.llvm.org/D105734

Reviewed-by: ymandel
This commit is contained in:
Felix Berger 2021-07-09 16:58:01 -04:00
parent 8ea1a630d6
commit 0ec812023b
2 changed files with 35 additions and 7 deletions
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33
clang-tools-extra/clang-tidy/performance/UnnecessaryCopyInitialization.cpp
View File

@ -39,14 +39,35 @@ void recordFixes(const VarDecl &Var, ASTContext &Context,
}
}
llvm::Optional<SourceLocation> firstLocAfterNewLine(SourceLocation Loc,
SourceManager &SM) {
bool Invalid;
const char *TextAfter = SM.getCharacterData(Loc, &Invalid);
if (Invalid) {
return llvm::None;
}
size_t Offset = std::strcspn(TextAfter, "\n");
return Loc.getLocWithOffset(TextAfter[Offset] == '\0' ? Offset : Offset + 1);
}
void recordRemoval(const DeclStmt &Stmt, ASTContext &Context,
DiagnosticBuilder &Diagnostic) {
// Attempt to remove the whole line until the next non-comment token.
auto Tok = utils::lexer::findNextTokenSkippingComments(
Stmt.getEndLoc(), Context.getSourceManager(), Context.getLangOpts());
if (Tok) {
Diagnostic << FixItHint::CreateRemoval(SourceRange(
Stmt.getBeginLoc(), Tok->getLocation().getLocWithOffset(-1)));
auto &SM = Context.getSourceManager();
// Attempt to remove trailing comments as well.
auto Tok = utils::lexer::findNextTokenSkippingComments(Stmt.getEndLoc(), SM,
Context.getLangOpts());
llvm::Optional<SourceLocation> PastNewLine =
firstLocAfterNewLine(Stmt.getEndLoc(), SM);
if (Tok && PastNewLine) {
auto BeforeFirstTokenAfterComment = Tok->getLocation().getLocWithOffset(-1);
// Remove until the end of the line or the end of a trailing comment which
// ever comes first.
auto End =
SM.isBeforeInTranslationUnit(*PastNewLine, BeforeFirstTokenAfterComment)
? *PastNewLine
: BeforeFirstTokenAfterComment;
Diagnostic << FixItHint::CreateRemoval(
SourceRange(Stmt.getBeginLoc(), End));
} else {
Diagnostic << FixItHint::CreateRemoval(Stmt.getSourceRange());
}

9
clang-tools-extra/test/clang-tidy/checkers/performance-unnecessary-copy-initialization.cpp
View File

@ -596,8 +596,15 @@ void positiveUnusedReferenceIsRemoved() {
// CHECK-FIXES: int i = 0; // Foo bar.
auto TrailingCommentRemoved = ExpensiveTypeReference(); // Trailing comment.
// CHECK-MESSAGES: [[@LINE-1]]:8: warning: the variable 'TrailingCommentRemoved' is copy-constructed from a const reference but is never used;
// CHECK-FIXES-NOT: auto TrailingCommentRemoved = ExpensiveTypeReference(); // Trailing comment.
// CHECK-FIXES-NOT: auto TrailingCommentRemoved = ExpensiveTypeReference();
// CHECK-FIXES-NOT: // Trailing comment.
// clang-format on
auto UnusedAndUnnecessary = ExpensiveTypeReference();
// Comments on a new line should not be deleted.
// CHECK-MESSAGES: [[@LINE-2]]:8: warning: the variable 'UnusedAndUnnecessary' is copy-constructed
// CHECK-FIXES-NOT: auto UnusedAndUnnecessary = ExpensiveTypeReference();
// CHECK-FIXES: // Comments on a new line should not be deleted.
}
void negativeloopedOverObjectIsModified() {