Author: Marek Kurdej Date: 2022-02-24T10:21:02+01:00 New Revision: bfb4afee74c8d6e3b1d020564bfe163073f07a04
URL: https://github.com/llvm/llvm-project/commit/bfb4afee74c8d6e3b1d020564bfe163073f07a04 DIFF: https://github.com/llvm/llvm-project/commit/bfb4afee74c8d6e3b1d020564bfe163073f07a04.diff LOG: [clang-format] Avoid inserting space after C++ casts. Fixes https://github.com/llvm/llvm-project/issues/53876. This is a solution for standard C++ casts: const_cast, dynamic_cast, reinterpret_cast, static_cast. A general approach handling all possible casts is not possible without semantic information. Consider the code: ``` static_cast<T>(*function_pointer_variable)(arguments); ``` vs. ``` some_return_type<T> (*function_pointer_variable)(parameters); // Later used as: function_pointer_variable = &some_function; return function_pointer_variable(args); ``` In the latter case, it's not a cast but a variable declaration of a pointer to function. Without knowing what `some_return_type<T>` is (and clang-format does not know it), it's hard to distinguish between the two cases. Theoretically, one could check whether "parameters" are types (not a cast) and "arguments" are value/expressions (a cast), but that might be inefficient (needs lots of lookahead). Reviewed By: MyDeveloperDay, HazardyKnusperkeks, owenpan Differential Revision: https://reviews.llvm.org/D120140 Added: Modified: clang/lib/Format/FormatToken.h clang/lib/Format/TokenAnnotator.cpp clang/unittests/Format/FormatTest.cpp Removed: ################################################################################ diff --git a/clang/lib/Format/FormatToken.h b/clang/lib/Format/FormatToken.h index bd1d447328a0..d1dc3ffb129d 100644 --- a/clang/lib/Format/FormatToken.h +++ b/clang/lib/Format/FormatToken.h @@ -43,6 +43,7 @@ namespace format { TYPE(ConflictAlternative) \ TYPE(ConflictEnd) \ TYPE(ConflictStart) \ + TYPE(CppCastLParen) \ TYPE(CtorInitializerColon) \ TYPE(CtorInitializerComma) \ TYPE(DesignatedInitializerLSquare) \ diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp index 01c215f6ad9d..36ff757922a9 100644 --- a/clang/lib/Format/TokenAnnotator.cpp +++ b/clang/lib/Format/TokenAnnotator.cpp @@ -358,7 +358,8 @@ class AnnotatingParser { if (CurrentToken->Previous->is(TT_BinaryOperator)) Contexts.back().IsExpression = true; if (CurrentToken->is(tok::r_paren)) { - if (MightBeFunctionType && ProbablyFunctionType && CurrentToken->Next && + if (Left->isNot(TT_CppCastLParen) && MightBeFunctionType && + ProbablyFunctionType && CurrentToken->Next && (CurrentToken->Next->is(tok::l_paren) || (CurrentToken->Next->is(tok::l_square) && Line.MustBeDeclaration))) Left->setType(Left->Next->is(tok::caret) ? TT_ObjCBlockLParen @@ -1733,6 +1734,9 @@ class AnnotatingParser { Current.Tok.setKind(tok::unknown); else Current.setType(TT_LineComment); + } else if (Current.is(tok::l_paren)) { + if (lParenStartsCppCast(Current)) + Current.setType(TT_CppCastLParen); } else if (Current.is(tok::r_paren)) { if (rParenEndsCast(Current)) Current.setType(TT_CastRParen); @@ -1880,6 +1884,25 @@ class AnnotatingParser { return Style.isJavaScript() && PreviousNotConst->is(tok::kw_const); } + /// Determine whether '(' is starting a C++ cast. + bool lParenStartsCppCast(const FormatToken &Tok) { + // C-style casts are only used in C++. + if (!Style.isCpp()) + return false; + + FormatToken *LeftOfParens = Tok.getPreviousNonComment(); + if (LeftOfParens && LeftOfParens->is(TT_TemplateCloser) && + LeftOfParens->MatchingParen) { + auto *Prev = LeftOfParens->MatchingParen->getPreviousNonComment(); + if (Prev && Prev->isOneOf(tok::kw_const_cast, tok::kw_dynamic_cast, + tok::kw_reinterpret_cast, tok::kw_static_cast)) + // FIXME: Maybe we should handle identifiers ending with "_cast", + // e.g. any_cast? + return true; + } + return false; + } + /// Determine whether ')' is ending a cast. bool rParenEndsCast(const FormatToken &Tok) { // C-style casts are only used in C++, C# and Java. diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp index 6cd6c4ab9a60..624f3a78755f 100644 --- a/clang/unittests/Format/FormatTest.cpp +++ b/clang/unittests/Format/FormatTest.cpp @@ -10570,6 +10570,19 @@ TEST_F(FormatTest, FormatsBinaryOperatorsPrecedingEquals) { TEST_F(FormatTest, FormatsCasts) { verifyFormat("Type *A = static_cast<Type *>(P);"); + verifyFormat("static_cast<Type *>(P);"); + verifyFormat("static_cast<Type &>(Fun)(Args);"); + verifyFormat("static_cast<Type &>(*Fun)(Args);"); + verifyFormat("if (static_cast<int>(A) + B >= 0)\n ;"); + // Check that static_cast<...>(...) does not require the next token to be on + // the same line. + verifyFormat("some_loooong_output << something_something__ << " + "static_cast<const void *>(R)\n" + " << something;"); + verifyFormat("a = static_cast<Type &>(*Fun)(Args);"); + verifyFormat("const_cast<Type &>(*Fun)(Args);"); + verifyFormat("dynamic_cast<Type &>(*Fun)(Args);"); + verifyFormat("reinterpret_cast<Type &>(*Fun)(Args);"); verifyFormat("Type *A = (Type *)P;"); verifyFormat("Type *A = (vector<Type *, int *>)P;"); verifyFormat("int a = (int)(2.0f);"); _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits