[PATCH] D120140: [clang-format] Avoid inserting space after C++ casts.
Marek Kurdej via Phabricator via cfe-commits
cfe-commits at lists.llvm.org
Fri Feb 18 09:25:22 PST 2022
curdeius created this revision.
curdeius added reviewers: MyDeveloperDay, HazardyKnusperkeks, owenpan.
curdeius requested review of this revision.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.
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).
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D120140
Files:
clang/lib/Format/TokenAnnotator.cpp
clang/unittests/Format/FormatTest.cpp
Index: clang/unittests/Format/FormatTest.cpp
===================================================================
--- clang/unittests/Format/FormatTest.cpp
+++ clang/unittests/Format/FormatTest.cpp
@@ -10565,6 +10565,13 @@
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("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);");
Index: clang/lib/Format/TokenAnnotator.cpp
===================================================================
--- clang/lib/Format/TokenAnnotator.cpp
+++ clang/lib/Format/TokenAnnotator.cpp
@@ -1734,8 +1734,11 @@
else
Current.setType(TT_LineComment);
} else if (Current.is(tok::r_paren)) {
- if (rParenEndsCast(Current))
+ if (rParenEndsCast(Current)) {
Current.setType(TT_CastRParen);
+ assert(Current.MatchingParen);
+ Current.MatchingParen->setType(TT_Unknown);
+ }
if (Current.MatchingParen && Current.Next &&
!Current.Next->isBinaryOperator() &&
!Current.Next->isOneOf(tok::semi, tok::colon, tok::l_brace,
@@ -1938,8 +1941,20 @@
// Certain other tokens right before the parentheses are also signals that
// this cannot be a cast.
+ if (LeftOfParens->is(TT_TemplateCloser)) {
+ if (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. bit_cast?
+ return true;
+ }
+ return false;
+ }
if (LeftOfParens->isOneOf(tok::at, tok::r_square, TT_OverloadedOperator,
- TT_TemplateCloser, tok::ellipsis))
+ tok::ellipsis))
return false;
}
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