================ @@ -0,0 +1,94 @@ +//===--- UseSpanFirstLastCheck.cpp - clang-tidy -----------------*- C++ -*-===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// + +#include "UseSpanFirstLastCheck.h" +#include "clang/AST/ASTContext.h" +#include "clang/AST/RecursiveASTVisitor.h" +#include "clang/ASTMatchers/ASTMatchFinder.h" +#include "clang/ASTMatchers/ASTMatchers.h" +#include "clang/Lex/Lexer.h" + +using namespace clang::ast_matchers; + +namespace clang::tidy::readability { + +void UseSpanFirstLastCheck::registerMatchers(MatchFinder *Finder) { + const auto HasSpanType = + hasType(hasUnqualifiedDesugaredType(recordType(hasDeclaration( + classTemplateSpecializationDecl(hasName("::std::span")))))); + + // Match span.subspan(0, n) -> first(n) + Finder->addMatcher( + cxxMemberCallExpr( + callee(memberExpr(hasDeclaration(cxxMethodDecl(hasName("subspan"))))), + on(expr(HasSpanType).bind("span_object")), + hasArgument(0, integerLiteral(equals(0))), + hasArgument(1, expr().bind("count")), argumentCountIs(2)) + .bind("first_subspan"), + this); + + // Match span.subspan(size() - n) -> last(n) + const auto SizeCall = cxxMemberCallExpr( + callee(memberExpr(hasDeclaration(cxxMethodDecl(hasName("size")))))); + + Finder->addMatcher( + cxxMemberCallExpr( + callee(memberExpr(hasDeclaration(cxxMethodDecl(hasName("subspan"))))), + on(expr(HasSpanType).bind("span_object")), + hasArgument(0, binaryOperator(hasOperatorName("-"), hasLHS(SizeCall), + hasRHS(expr().bind("count")))), + argumentCountIs(1)) + .bind("last_subspan"), + this); +} + +void UseSpanFirstLastCheck::check(const MatchFinder::MatchResult &Result) { + const auto *SpanObj = Result.Nodes.getNodeAs<Expr>("span_object"); + if (!SpanObj) + return; + + StringRef SpanText = Lexer::getSourceText( + CharSourceRange::getTokenRange(SpanObj->getSourceRange()), + *Result.SourceManager, Result.Context->getLangOpts()); + + if (const auto *FirstCall = + Result.Nodes.getNodeAs<CXXMemberCallExpr>("first_subspan")) { + const auto *Count = Result.Nodes.getNodeAs<Expr>("count"); + if (!Count) + return; + + StringRef CountText = Lexer::getSourceText( + CharSourceRange::getTokenRange(Count->getSourceRange()), + *Result.SourceManager, Result.Context->getLangOpts()); + + std::string Replacement = + SpanText.str() + ".first(" + CountText.str() + ")"; + + diag(FirstCall->getBeginLoc(), "prefer 'span::first()' over 'subspan()'") + << FixItHint::CreateReplacement(FirstCall->getSourceRange(), + Replacement); + } + + if (const auto *LastCall = + Result.Nodes.getNodeAs<CXXMemberCallExpr>("last_subspan")) { + const auto *Count = Result.Nodes.getNodeAs<Expr>("count"); + if (!Count) + return; ---------------- HerrCai0907 wrote:
can be assert https://github.com/llvm/llvm-project/pull/118074 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
