[clang-tidy][NFC] Clean up and slightly optimize modernize-use-integer-sign-comparison
#163492
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
…er-sign-comparison`
|
@llvm/pr-subscribers-clang-tools-extra @llvm/pr-subscribers-clang-tidy Author: Victor Chernyakin (localspook) ChangesFull diff: https://github.com/llvm/llvm-project/pull/163492.diff 1 Files Affected:
diff --git a/clang-tools-extra/clang-tidy/modernize/UseIntegerSignComparisonCheck.cpp b/clang-tools-extra/clang-tidy/modernize/UseIntegerSignComparisonCheck.cpp
index 0003429c62890..a3d3f0fa0ec93 100644
--- a/clang-tools-extra/clang-tidy/modernize/UseIntegerSignComparisonCheck.cpp
+++ b/clang-tools-extra/clang-tidy/modernize/UseIntegerSignComparisonCheck.cpp
@@ -34,13 +34,12 @@ AST_MATCHER(clang::QualType, isActualChar) {
} // namespace
static BindableMatcher<clang::Stmt>
-intCastExpression(bool IsSigned,
- const std::string &CastBindName = std::string()) {
+intCastExpression(bool IsSigned, StringRef CastBindName = {}) {
// std::cmp_{} functions trigger a compile-time error if either LHS or RHS
// is a non-integer type, char, enum or bool
// (unsigned char/ signed char are Ok and can be used).
auto IntTypeExpr = expr(hasType(hasCanonicalType(qualType(
- isInteger(), IsSigned ? isSignedInteger() : isUnsignedInteger(),
+ IsSigned ? isSignedInteger() : isUnsignedInteger(),
unless(isActualChar()), unless(booleanType()), unless(enumType())))));
const auto ImplicitCastExpr =
@@ -71,7 +70,7 @@ static StringRef parseOpCode(BinaryOperator::Opcode Code) {
case BO_NE:
return "cmp_not_equal";
default:
- return "";
+ llvm_unreachable("invalid opcode");
}
}
@@ -119,23 +118,16 @@ void UseIntegerSignComparisonCheck::check(
Expr::EvalResult EVResult;
if (!SignedCastExpression->isValueDependent() &&
SignedCastExpression->getSubExpr()->EvaluateAsInt(EVResult,
- *Result.Context)) {
- const llvm::APSInt SValue = EVResult.Val.getInt();
- if (SValue.isNonNegative())
- return;
- }
+ *Result.Context) &&
+ EVResult.Val.getInt().isNonNegative())
+ return;
const auto *BinaryOp =
Result.Nodes.getNodeAs<BinaryOperator>("intComparison");
- if (BinaryOp == nullptr)
- return;
-
- const BinaryOperator::Opcode OpCode = BinaryOp->getOpcode();
+ assert(BinaryOp);
const Expr *LHS = BinaryOp->getLHS()->IgnoreImpCasts();
const Expr *RHS = BinaryOp->getRHS()->IgnoreImpCasts();
- if (LHS == nullptr || RHS == nullptr)
- return;
const Expr *SubExprLHS = nullptr;
const Expr *SubExprRHS = nullptr;
SourceRange R1(LHS->getBeginLoc());
@@ -144,8 +136,7 @@ void UseIntegerSignComparisonCheck::check(
RHS->getEndLoc(), 0, *Result.SourceManager, getLangOpts()));
if (const auto *LHSCast = llvm::dyn_cast<ExplicitCastExpr>(LHS)) {
SubExprLHS = LHSCast->getSubExpr();
- R1 = SourceRange(LHS->getBeginLoc(),
- SubExprLHS->getBeginLoc().getLocWithOffset(-1));
+ R1.setEnd(SubExprLHS->getBeginLoc().getLocWithOffset(-1));
R2.setBegin(Lexer::getLocForEndOfToken(
SubExprLHS->getEndLoc(), 0, *Result.SourceManager, getLangOpts()));
}
@@ -156,21 +147,21 @@ void UseIntegerSignComparisonCheck::check(
DiagnosticBuilder Diag =
diag(BinaryOp->getBeginLoc(),
"comparison between 'signed' and 'unsigned' integers");
- std::string CmpNamespace;
- llvm::StringRef CmpHeader;
+ StringRef CmpNamespace;
+ StringRef CmpHeader;
if (getLangOpts().CPlusPlus20) {
CmpHeader = "<utility>";
- CmpNamespace = llvm::Twine("std::" + parseOpCode(OpCode)).str();
+ CmpNamespace = "std::";
} else if (getLangOpts().CPlusPlus17 && EnableQtSupport) {
CmpHeader = "<QtCore/q20utility.h>";
- CmpNamespace = llvm::Twine("q20::" + parseOpCode(OpCode)).str();
+ CmpNamespace = "q20::";
}
// Prefer modernize-use-integer-sign-comparison when C++20 is available!
Diag << FixItHint::CreateReplacement(
CharSourceRange(R1, SubExprLHS != nullptr),
- llvm::Twine(CmpNamespace + "(").str());
+ Twine(CmpNamespace + parseOpCode(BinaryOp->getOpcode()) + "(").str());
Diag << FixItHint::CreateReplacement(R2, ",");
Diag << FixItHint::CreateReplacement(CharSourceRange::getCharRange(R3), ")");
|
localspook
commented
Oct 15, 2025
| // is a non-integer type, char, enum or bool | ||
| // (unsigned char/ signed char are Ok and can be used). | ||
| auto IntTypeExpr = expr(hasType(hasCanonicalType(qualType( | ||
| isInteger(), IsSigned ? isSignedInteger() : isUnsignedInteger(), |
There was a problem hiding this comment.
isInteger() is redundant when we have isSignedInteger() or isUnsignedInteger()
| if (!SignedCastExpression->isValueDependent() && | ||
| SignedCastExpression->getSubExpr()->EvaluateAsInt(EVResult, | ||
| *Result.Context)) { | ||
| const llvm::APSInt SValue = EVResult.Val.getInt(); |
There was a problem hiding this comment.
getInt() returns a reference, so this is an unnecessary copy
| const Expr *LHS = BinaryOp->getLHS()->IgnoreImpCasts(); | ||
| const Expr *RHS = BinaryOp->getRHS()->IgnoreImpCasts(); | ||
| if (LHS == nullptr || RHS == nullptr) | ||
| return; |
There was a problem hiding this comment.
I don't believe either of BinaryOperation's subexpressions can be null
There was a problem hiding this comment.
But can IgnoreImpCasts return null? (Genuine question, I'll look into sources a bit later)
There was a problem hiding this comment.
I would be surprised if it did; in my understanding, all it does is optionally skip past some AST nodes, so what would cause it to return null? (It would be good to check though, yep)
There was a problem hiding this comment.
IgnoreImpCasts repeatedly applies this function to the Expr it's called on:
llvm-project/clang/include/clang/AST/IgnoreExpr.h
Lines 48 to 56 in 4d6f43d
until it reaches a fixed point. I don't think
ImplicitCastExpr or FullExpr can have a null subexpression, so I think this change is safe
| static BindableMatcher<clang::Stmt> | ||
| intCastExpression(bool IsSigned, | ||
| const std::string &CastBindName = std::string()) { | ||
| intCastExpression(bool IsSigned, StringRef CastBindName = {}) { |
There was a problem hiding this comment.
StringRef is enough here, we don't need std::string
| SubExprLHS = LHSCast->getSubExpr(); | ||
| R1 = SourceRange(LHS->getBeginLoc(), | ||
| SubExprLHS->getBeginLoc().getLocWithOffset(-1)); | ||
| R1.setEnd(SubExprLHS->getBeginLoc().getLocWithOffset(-1)); |
There was a problem hiding this comment.
At this point, R1's begin location is already equal to LHS->getBeginLoc(), so we only need to update the end location
| Diag << FixItHint::CreateReplacement( | ||
| CharSourceRange(R1, SubExprLHS != nullptr), | ||
| llvm::Twine(CmpNamespace + "(").str()); | ||
| Twine(CmpNamespace + parseOpCode(BinaryOp->getOpcode()) + "(").str()); |
There was a problem hiding this comment.
Moving the parseOpCode() call down here removes the duplication above
localspook
requested review from
5chmidti,
EugeneZelenko,
HerrCai0907,
PiotrZSL,
carlosgalvezp and
vbvictor
vbvictor
approved these changes
Oct 15, 2025
|
LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/144/builds/38185 Here is the relevant piece of the build log for the reference |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
4 participants
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
No description provided.