[clang-tools-extra] [llvm] [clang] Add clang-tidy check to suggest replacement of conditional statement with std::min/std::max (PR #77816)
Julian Schmidt via cfe-commits
cfe-commits at lists.llvm.org
Fri Jan 19 06:11:01 PST 2024
================
@@ -0,0 +1,143 @@
+//===--- UseStdMinMaxCheck.cpp - clang-tidy -------------------------------===//
+//
+// 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 "UseStdMinMaxCheck.h"
+#include "../utils/ASTUtils.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/Lex/Preprocessor.h"
+#include <optional>
+
+using namespace clang::ast_matchers;
+
+namespace clang::tidy::readability {
+
+UseStdMinMaxCheck::UseStdMinMaxCheck(StringRef Name, ClangTidyContext *Context)
+ : ClangTidyCheck(Name, Context),
+ IncludeInserter(Options.getLocalOrGlobal("IncludeStyle",
+ utils::IncludeSorter::IS_LLVM),
+ areDiagsSelfContained()) {}
+
+void UseStdMinMaxCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
+ Options.store(Opts, "IncludeStyle", IncludeInserter.getStyle());
+ Options.store(Opts, "AlgorithmHeader",
+ Options.get("AlgorithmHeader", "<algorithm>"));
+}
+
+void UseStdMinMaxCheck::registerMatchers(MatchFinder *Finder) {
+ Finder->addMatcher(
+ ifStmt(
+ hasCondition(binaryOperator(hasAnyOperatorName("<", ">", "<=", ">="),
+ hasLHS(expr().bind("CondLhs")),
+ hasRHS(expr().bind("CondRhs")))),
+ hasThen(anyOf(stmt(binaryOperator(hasOperatorName("="),
+ hasLHS(expr().bind("AssignLhs")),
+ hasRHS(expr().bind("AssignRhs")))),
+ compoundStmt(has(binaryOperator(
+ hasOperatorName("="),
+ hasLHS(expr().bind("AssignLhs")),
+ hasRHS(expr().bind("AssignRhs")))))
+ .bind("compound"))))
+ .bind("if"),
+ this);
+}
+
+void UseStdMinMaxCheck::registerPPCallbacks(const SourceManager &SM,
+ Preprocessor *PP,
+ Preprocessor *ModuleExpanderPP) {
+ IncludeInserter.registerPreprocessor(PP);
+}
+
+void UseStdMinMaxCheck::check(const MatchFinder::MatchResult &Result) {
+ const auto *CondLhs = Result.Nodes.getNodeAs<Expr>("CondLhs");
+ const auto *CondRhs = Result.Nodes.getNodeAs<Expr>("CondRhs");
+ const auto *AssignLhs = Result.Nodes.getNodeAs<Expr>("AssignLhs");
+ const auto *AssignRhs = Result.Nodes.getNodeAs<Expr>("AssignRhs");
+ const auto *If = Result.Nodes.getNodeAs<IfStmt>("if");
+ const auto *Compound = Result.Nodes.getNodeAs<CompoundStmt>("compound");
+ auto &Context = *Result.Context;
+ const SourceManager &Source = Context.getSourceManager();
+
+ const auto *BinaryOp = dyn_cast<BinaryOperator>(If->getCond());
+ if (!BinaryOp || If->hasElseStorage())
+ return;
+
+ if (Compound) {
+ int count = 0;
+ clang::Stmt::const_child_iterator I = Compound->child_begin();
+ clang::Stmt::const_child_iterator E = Compound->child_end();
+ for (; I != E; ++I) {
+ count++;
+ }
+ if (count > 1)
+ return;
+ }
+
+ SourceLocation IfLocation = If->getIfLoc();
+ SourceLocation ThenLocation = If->getEndLoc();
+
+ if (IfLocation.isMacroID() || ThenLocation.isMacroID())
+ return;
+
+ const auto CondLhsStr =
+ Lexer::getSourceText(Source.getExpansionRange(CondLhs->getSourceRange()),
+ Context.getSourceManager(), Context.getLangOpts());
+
+ const auto AssignLhsStr = Lexer::getSourceText(
+ Source.getExpansionRange(AssignLhs->getSourceRange()),
+ Context.getSourceManager(), Context.getLangOpts());
+
+ const auto CondRhsStr =
+ Lexer::getSourceText(Source.getExpansionRange(CondRhs->getSourceRange()),
+ Context.getSourceManager(), Context.getLangOpts());
+
+ auto CreateMaxReplacement = [&]() {
+ return AssignLhsStr.str() + " = std::max(" + CondLhsStr.str() + ", " +
+ CondRhsStr.str() + ");";
+ };
+
+ auto CreateMinReplacement = [&]() {
+ return AssignLhsStr.str() + " = std::min(" + CondLhsStr.str() + ", " +
+ CondRhsStr.str() + ");";
+ };
----------------
5chmidti wrote:
Please use `(AssignLhsStr + " = std::max(" + CondLhsStr + ", " + CondRhsStr + ");").str()` instead of calling `.str()` on the `StringRef`s. This way, only a single `std::string` is created.
https://github.com/llvm/llvm-project/pull/77816
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