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[clang-format] Fix a bug in parsing C-style cast of lambdas #136099

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Merged
merged 2 commits into from
Apr 23, 2025
Merged

[clang-format] Fix a bug in parsing C-style cast of lambdas #136099

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53033b2
[clang-format] Fix a bug in parsing C-style cast lambda
owenca Apr 17, 2025
3dd4a35
Also handle casting to function pointer types
owenca Apr 19, 2025
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24 changes: 18 additions & 6 deletions clang/lib/Format/UnwrappedLineParser.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -2368,13 +2368,25 @@ bool UnwrappedLineParser::tryToParseLambdaIntroducer() {
const FormatToken *Previous = FormatTok->Previous;
const FormatToken *LeftSquare = FormatTok;
nextToken();
if ((Previous && ((Previous->Tok.getIdentifierInfo() &&
!Previous->isOneOf(tok::kw_return, tok::kw_co_await,
tok::kw_co_yield, tok::kw_co_return)) ||
Previous->closesScope())) ||
LeftSquare->isCppStructuredBinding(IsCpp)) {
return false;
if (Previous) {
if (Previous->Tok.getIdentifierInfo() &&
!Previous->isOneOf(tok::kw_return, tok::kw_co_await, tok::kw_co_yield,
tok::kw_co_return)) {
return false;
}
if (Previous->closesScope()) {
// Not a potential C-style cast.
if (Previous->isNot(tok::r_paren))
return false;
const auto *BeforeRParen = Previous->getPreviousNonComment();
// Lambdas can be cast to function types only, e.g. `std::function<int()>`
// and `int (*)()`.
if (!BeforeRParen || !BeforeRParen->isOneOf(tok::greater, tok::r_paren))
return false;
}
}
if (LeftSquare->isCppStructuredBinding(IsCpp))
return false;
if (FormatTok->is(tok::l_square) || tok::isLiteral(FormatTok->Tok.getKind()))
return false;
if (FormatTok->is(tok::r_square)) {
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10 changes: 10 additions & 0 deletions clang/unittests/Format/TokenAnnotatorTest.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -2159,6 +2159,16 @@ TEST_F(TokenAnnotatorTest, UnderstandsLambdas) {
// FIXME:
// EXPECT_TOKEN(Tokens[13], tok::l_paren, TT_LambdaDefinitionLParen);
EXPECT_TOKEN(Tokens[17], tok::l_brace, TT_LambdaLBrace);

Tokens = annotate("auto foo{(std::function<int()>)[] { return 0; }};");
ASSERT_EQ(Tokens.size(), 23u) << Tokens;
EXPECT_TOKEN(Tokens[13], tok::l_square, TT_LambdaLSquare);
EXPECT_TOKEN(Tokens[15], tok::l_brace, TT_LambdaLBrace);

Tokens = annotate("auto foo{(int (*)())[] { return 0; }};");
ASSERT_EQ(Tokens.size(), 21u) << Tokens;
EXPECT_TOKEN(Tokens[11], tok::l_square, TT_LambdaLSquare);
EXPECT_TOKEN(Tokens[13], tok::l_brace, TT_LambdaLBrace);
}

TEST_F(TokenAnnotatorTest, UnderstandsFunctionAnnotations) {
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