[clang] [llvm] [clang-tools-extra] Add clang-tidy check to suggest replacement of conditional statement with std::min/std::max (PR #77816)

[Bhuminjay Soni via llvm-commits]

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@@ -0,0 +1,168 @@
+//===--- 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"
+
+using namespace clang::ast_matchers;
+
+namespace clang::tidy::readability {
+
+static const llvm::StringRef AlgorithmHeader("<algorithm>");
+
+static bool minCondition(const BinaryOperator::Opcode Op, const Expr *CondLhs,
+                         const Expr *CondRhs, const Expr *AssignLhs,
+                         const Expr *AssignRhs, const ASTContext &Context) {
+  if ((Op == BO_LT || Op == BO_LE) &&
+      (tidy::utils::areStatementsIdentical(CondLhs, AssignRhs, Context) &&
+       tidy::utils::areStatementsIdentical(CondRhs, AssignLhs, Context)))
+    return true;
+
+  if ((Op == BO_GT || Op == BO_GE) &&
+      (tidy::utils::areStatementsIdentical(CondLhs, AssignLhs, Context) &&
+       tidy::utils::areStatementsIdentical(CondRhs, AssignRhs, Context)))
+    return true;
+
+  return false;
+}
+
+static bool maxCondition(const BinaryOperator::Opcode Op, const Expr *CondLhs,
+                         const Expr *CondRhs, const Expr *AssignLhs,
+                         const Expr *AssignRhs, const ASTContext &Context) {
+  if ((Op == BO_LT || Op == BO_LE) &&
+      (tidy::utils::areStatementsIdentical(CondLhs, AssignLhs, Context) &&
+       tidy::utils::areStatementsIdentical(CondRhs, AssignRhs, Context)))
+    return true;
+
+  if ((Op == BO_GT || Op == BO_GE) &&
+      (tidy::utils::areStatementsIdentical(CondLhs, AssignRhs, Context) &&
+       tidy::utils::areStatementsIdentical(CondRhs, AssignLhs, Context)))
+    return true;
+
+  return false;
+}
+
+static std::string createReplacement(const Expr *CondLhs, const Expr *CondRhs,
+                                     const Expr *AssignLhs,
+                                     const SourceManager &Source,
+                                     const LangOptions &LO,
+                                     StringRef FunctionName,
+                                     const BinaryOperator *BO) {
+  const llvm::StringRef CondLhsStr = Lexer::getSourceText(
+      Source.getExpansionRange(CondLhs->getSourceRange()), Source, LO);
+  const llvm::StringRef CondRhsStr = Lexer::getSourceText(
+      Source.getExpansionRange(CondRhs->getSourceRange()), Source, LO);
+  const llvm::StringRef AssignLhsStr = Lexer::getSourceText(
+      Source.getExpansionRange(AssignLhs->getSourceRange()), Source, LO);
+
+  clang::QualType GlobalImplicitCastType;
+  if (CondLhs->getType()
+          .getCanonicalType()
+          .getNonReferenceType()
+          .getUnqualifiedType() != CondRhs->getType()
+                                       .getCanonicalType()
+                                       .getNonReferenceType()
+                                       .getUnqualifiedType()) {
+    GlobalImplicitCastType = BO->getLHS()->getType();
+  }
+
+  return (AssignLhsStr + " = " + FunctionName +
+          (!GlobalImplicitCastType.isNull()
+               ? "<" + GlobalImplicitCastType.getCanonicalType().getAsString() +
+                     ">("
+               : "(") +
+          CondLhsStr + ", " + CondRhsStr + ");")
+      .str();
+}
+
+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());
+}
+
+// Ignore if statements that are inside macros.
+AST_MATCHER(IfStmt, isIfInMacro) {
+  return Node.getIfLoc().isMacroID() || Node.getEndLoc().isMacroID();
+}
+
+// Ignore expressions that are of dependent types.
+AST_MATCHER(Expr, isExprDependentType) {
+  return Node.getType()->isDependentType();
+}
+
+void UseStdMinMaxCheck::registerMatchers(MatchFinder *Finder) {
+  auto AssignOperator =
+      binaryOperator(hasOperatorName("="), hasLHS(expr().bind("AssignLhs")),
+                     hasRHS(expr().bind("AssignRhs")));
+  auto BinaryOperator =
+      binaryOperator(
----------------
11happy wrote:

done

https://github.com/llvm/llvm-project/pull/77816