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@earnol earnol commented Jan 7, 2025

This patch addresses situations when misc-redundant-expression checker provides excessive diagnostics for situations with different macros having the same value. In particular it addresses situations described in the initial report of #118885 are addressed. The situations which are popped inside discussion like if (A + B == B + A) for macros are not properly addressed by this patch.

Accidentally closed the pull request and since i have no rights to reopen i created a new one:
#122841

@llvmbot
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llvmbot commented Jan 7, 2025

@llvm/pr-subscribers-clang

@llvm/pr-subscribers-clang-tools-extra

Author: None (earnol)

Changes

This patch addresses situations when misc-redundant-expression checker provides excessive diagnostics for situations with different macros having the same value. In particular it addresses situations described in the initial report of #118885 are addressed. The situations which are popped inside discussion like if (A + B == B + A) for macros are not properly addressed by this patch.


Full diff: https://github.com/llvm/llvm-project/pull/121960.diff

2 Files Affected:

  • (modified) clang-tools-extra/clang-tidy/misc/RedundantExpressionCheck.cpp (+99-19)
  • (modified) clang-tools-extra/test/clang-tidy/checkers/misc/redundant-expression.cpp (+150)
diff --git a/clang-tools-extra/clang-tidy/misc/RedundantExpressionCheck.cpp b/clang-tools-extra/clang-tidy/misc/RedundantExpressionCheck.cpp
index fc35bc22c52e04..d6136c40d64cc8 100644
--- a/clang-tools-extra/clang-tidy/misc/RedundantExpressionCheck.cpp
+++ b/clang-tools-extra/clang-tidy/misc/RedundantExpressionCheck.cpp
@@ -139,10 +139,8 @@ static bool areEquivalentExpr(const Expr *Left, const Expr *Right) {
     return cast<BinaryOperator>(Left)->getOpcode() ==
            cast<BinaryOperator>(Right)->getOpcode();
   case Stmt::UnaryExprOrTypeTraitExprClass:
-    const auto *LeftUnaryExpr =
-        cast<UnaryExprOrTypeTraitExpr>(Left);
-    const auto *RightUnaryExpr =
-        cast<UnaryExprOrTypeTraitExpr>(Right);
+    const auto *LeftUnaryExpr = cast<UnaryExprOrTypeTraitExpr>(Left);
+    const auto *RightUnaryExpr = cast<UnaryExprOrTypeTraitExpr>(Right);
     if (LeftUnaryExpr->isArgumentType() && RightUnaryExpr->isArgumentType())
       return LeftUnaryExpr->getKind() == RightUnaryExpr->getKind() &&
              LeftUnaryExpr->getArgumentType() ==
@@ -699,7 +697,8 @@ static bool retrieveRelationalIntegerConstantExpr(
 
     Symbol = OverloadedOperatorExpr->getArg(IntegerConstantIsFirstArg ? 1 : 0);
     OperandExpr = OverloadedOperatorExpr;
-    Opcode = BinaryOperator::getOverloadedOpcode(OverloadedOperatorExpr->getOperator());
+    Opcode = BinaryOperator::getOverloadedOpcode(
+        OverloadedOperatorExpr->getOperator());
 
     if (!retrieveIntegerConstantExpr(Result, Id, Value, ConstExpr))
       return false;
@@ -728,7 +727,8 @@ static bool retrieveRelationalIntegerConstantExpr(
 }
 
 // Checks for expressions like (X == 4) && (Y != 9)
-static bool areSidesBinaryConstExpressions(const BinaryOperator *&BinOp, const ASTContext *AstCtx) {
+static bool areSidesBinaryConstExpressions(const BinaryOperator *&BinOp,
+                                           const ASTContext *AstCtx) {
   const auto *LhsBinOp = dyn_cast<BinaryOperator>(BinOp->getLHS());
   const auto *RhsBinOp = dyn_cast<BinaryOperator>(BinOp->getRHS());
 
@@ -747,6 +747,31 @@ static bool areSidesBinaryConstExpressions(const BinaryOperator *&BinOp, const A
   return false;
 }
 
+static bool
+areSidesBinaryConstExpressionsOrDefines(const BinaryOperator *&BinOp,
+                                        const ASTContext *AstCtx) {
+  if (areSidesBinaryConstExpressions(BinOp, AstCtx))
+    return true;
+
+  const auto *Lhs = BinOp->getLHS();
+  const auto *Rhs = BinOp->getRHS();
+
+  if (!Lhs || !Rhs)
+    return false;
+
+  auto IsDefineExpr = [AstCtx](const Expr *E) {
+    SourceRange Lsr = E->getSourceRange();
+    if (!Lsr.getBegin().isMacroID() || E->isValueDependent() ||
+        !E->isIntegerConstantExpr(*AstCtx))
+      return false;
+    return true;
+  };
+
+  if (IsDefineExpr(Lhs) || IsDefineExpr(Rhs))
+    return true;
+  return false;
+}
+
 // Retrieves integer constant subexpressions from binary operator expressions
 // that have two equivalent sides.
 // E.g.: from (X == 5) && (X == 5) retrieves 5 and 5.
@@ -785,7 +810,7 @@ static bool retrieveConstExprFromBothSides(const BinaryOperator *&BinOp,
 }
 
 static bool isSameRawIdentifierToken(const Token &T1, const Token &T2,
-                        const SourceManager &SM) {
+                                     const SourceManager &SM) {
   if (T1.getKind() != T2.getKind())
     return false;
   if (T1.isNot(tok::raw_identifier))
@@ -852,6 +877,58 @@ static bool areExprsMacroAndNonMacro(const Expr *&LhsExpr,
 
   return LhsLoc.isMacroID() != RhsLoc.isMacroID();
 }
+
+static bool areExprsSameMacroOrLiteral(const BinaryOperator *BinOp,
+                                       const ASTContext *Context) {
+
+  if (!BinOp)
+    return false;
+
+  const auto *Lhs = BinOp->getLHS();
+  const auto *Rhs = BinOp->getRHS();
+  const SourceManager &SM = Context->getSourceManager();
+
+  SourceRange Lsr = Lhs->getSourceRange();
+  SourceRange Rsr = Rhs->getSourceRange();
+  if (Lsr.getBegin().isMacroID()) {
+    // Left is macro so right macro too
+    if (Rsr.getBegin().isMacroID()) {
+      // Both sides are macros so they are same macro or literal
+      llvm::StringRef L = Lexer::getSourceText(
+          CharSourceRange::getTokenRange(Lsr), SM, LangOptions(), 0);
+      llvm::StringRef R = Lexer::getSourceText(
+          CharSourceRange::getTokenRange(Rsr), SM, LangOptions(), 0);
+      return L.compare(R) == 0;
+    }
+    // Left is macro but right is not so they are not same macro or literal
+    return false;
+  } else {
+    const IntegerLiteral *Lil = dyn_cast<IntegerLiteral>(Lhs);
+    const IntegerLiteral *Ril = dyn_cast<IntegerLiteral>(Rhs);
+    if (Lil && Ril) {
+      return Lil->getValue() == Ril->getValue();
+    }
+
+    const StringLiteral *LStrl = dyn_cast<StringLiteral>(Lhs);
+    const StringLiteral *RStrl = dyn_cast<StringLiteral>(Rhs);
+    if (Lil && Ril) {
+      llvm::StringRef L = Lexer::getSourceText(
+          CharSourceRange::getTokenRange(LStrl->getBeginLoc()), SM,
+          LangOptions(), 0);
+      llvm::StringRef R = Lexer::getSourceText(
+          CharSourceRange::getTokenRange(RStrl->getBeginLoc()), SM,
+          LangOptions(), 0);
+      return L.compare(R) == 0;
+    }
+
+    const CXXBoolLiteralExpr *Lbl = dyn_cast<CXXBoolLiteralExpr>(Lhs);
+    const CXXBoolLiteralExpr *Rbl = dyn_cast<CXXBoolLiteralExpr>(Rhs);
+    if (Lbl && Rbl) {
+      return Lbl->getValue() == Rbl->getValue();
+    }
+  }
+  return false;
+}
 } // namespace
 
 void RedundantExpressionCheck::registerMatchers(MatchFinder *Finder) {
@@ -1089,7 +1166,6 @@ static bool exprEvaluatesToSymbolic(BinaryOperatorKind Opcode, APSInt Value) {
          ((Opcode == BO_And || Opcode == BO_AndAssign) && ~Value == 0);
 }
 
-
 void RedundantExpressionCheck::checkBitwiseExpr(
     const MatchFinder::MatchResult &Result) {
   if (const auto *ComparisonOperator = Result.Nodes.getNodeAs<BinaryOperator>(
@@ -1134,8 +1210,8 @@ void RedundantExpressionCheck::checkBitwiseExpr(
                                      ConstExpr))
       return;
 
-    if((Value != 0 && ~Value != 0) || Sym->getExprLoc().isMacroID())
-        return;
+    if ((Value != 0 && ~Value != 0) || Sym->getExprLoc().isMacroID())
+      return;
 
     SourceLocation Loc = IneffectiveOperator->getOperatorLoc();
 
@@ -1276,17 +1352,21 @@ void RedundantExpressionCheck::check(const MatchFinder::MatchResult &Result) {
       return;
     }
 
-    if (areSidesBinaryConstExpressions(BinOp, Result.Context)) {
+    if (areSidesBinaryConstExpressionsOrDefines(BinOp, Result.Context)) {
       const Expr *LhsConst = nullptr, *RhsConst = nullptr;
       BinaryOperatorKind MainOpcode{}, SideOpcode{};
-
-      if (!retrieveConstExprFromBothSides(BinOp, MainOpcode, SideOpcode,
-                                          LhsConst, RhsConst, Result.Context))
-        return;
-
-      if (areExprsFromDifferentMacros(LhsConst, RhsConst, Result.Context) ||
-          areExprsMacroAndNonMacro(LhsConst, RhsConst))
-        return;
+      if (areSidesBinaryConstExpressions(BinOp, Result.Context)) {
+        if (!retrieveConstExprFromBothSides(BinOp, MainOpcode, SideOpcode,
+                                            LhsConst, RhsConst, Result.Context))
+          return;
+
+        if (areExprsFromDifferentMacros(LhsConst, RhsConst, Result.Context) ||
+            areExprsMacroAndNonMacro(LhsConst, RhsConst))
+          return;
+      } else {
+        if (!areExprsSameMacroOrLiteral(BinOp, Result.Context))
+          return;
+      }
     }
 
     diag(BinOp->getOperatorLoc(), "both sides of operator are equivalent");
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/redundant-expression.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/redundant-expression.cpp
index 7396d2dce76c43..75a73808900724 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/misc/redundant-expression.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/misc/redundant-expression.cpp
@@ -1,4 +1,5 @@
 // RUN: %check_clang_tidy %s misc-redundant-expression %t -- -- -fno-delayed-template-parsing -Wno-array-compare-cxx26
+// RUN: %check_clang_tidy %s misc-redundant-expression %t -- -- -fno-delayed-template-parsing -Wno-array-compare-cxx26 -DTEST_MACRO
 
 typedef __INT64_TYPE__ I64;
 
@@ -91,6 +92,155 @@ int TestSimpleEquivalent(int X, int Y) {
   return 0;
 }
 
+#ifndef TEST_MACRO
+#define VAL_1 2
+#define VAL_3 3
+#else
+#define VAL_1 3
+#define VAL_3 2
+#endif
+
+#define VAL_2 2
+
+#ifndef TEST_MACRO
+#define VAL_4 2 + 1
+#define VAL_6 3 + 1
+#else
+#define VAL_4 3 + 1
+#define VAL_6 2 + 1
+#endif
+
+#define VAL_5 2 + 1
+
+struct TestStruct
+{
+  int mA;
+  int mB;
+  int mC[10];
+};
+
+int TestDefineEquivalent() {
+
+  int int_val1 = 3;
+  int int_val2 = 4;
+  int int_val = 0;
+  const int cint_val2 = 4;
+
+  // Cases which should not be reported
+  if (VAL_1 != VAL_2)  return 0;
+  if (VAL_3 != VAL_2)  return 0;
+  if (VAL_1 == VAL_2)  return 0;
+  if (VAL_3 == VAL_2)  return 0;
+  if (VAL_1 >= VAL_2)  return 0;
+  if (VAL_3 >= VAL_2)  return 0;
+  if (VAL_1 <= VAL_2)  return 0;
+  if (VAL_3 <= VAL_2)  return 0;
+  if (VAL_1 < VAL_2)  return 0;
+  if (VAL_3 < VAL_2)  return 0;
+  if (VAL_1 > VAL_2)  return 0;
+  if (VAL_3 > VAL_2)  return 0;
+
+  if (VAL_4 != VAL_5)  return 0;
+  if (VAL_6 != VAL_5)  return 0;
+  if (VAL_6 == VAL_5)  return 0;
+  if (VAL_4 >= VAL_5)  return 0;
+  if (VAL_6 >= VAL_5)  return 0;
+  if (VAL_4 <= VAL_5)  return 0;
+  if (VAL_6 <= VAL_5)  return 0;
+  if (VAL_4 > VAL_5)  return 0;
+  if (VAL_6 > VAL_5)  return 0;
+  if (VAL_4 < VAL_5)  return 0;
+  if (VAL_6 < VAL_5)  return 0;
+
+  if (VAL_1 != 2)  return 0;
+  if (VAL_3 == 3)  return 0;
+
+  if (VAL_1 >= VAL_1)  return 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: both sides of operator are equivalent
+  if (VAL_2 <= VAL_2)  return 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: both sides of operator are equivalent
+  if (VAL_3 > VAL_3)  return 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: both sides of operator are equivalent
+  if (VAL_4 < VAL_4)  return 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: both sides of operator are equivalent
+  if (VAL_6 == VAL_6) return 2;
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: both sides of operator are equivalent
+  if (VAL_5 != VAL_5) return 2;
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: both sides of operator are equivalent
+
+  if (1 >= 1)  return 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both sides of operator are equivalent
+  if (0xFF <= 0xFF)  return 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: both sides of operator are equivalent
+  if (042 > 042)  return 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:11: warning: both sides of operator are equivalent
+
+  int_val = (VAL_6 == VAL_6)?int_val1: int_val2;
+  // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: both sides of operator are equivalent
+  int_val = (042 > 042)?int_val1: int_val2;
+  // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: both sides of operator are equivalent
+
+
+  // Ternary operator cases which should not be reported
+  int_val = (VAL_4 == VAL_5)? int_val1: int_val2;
+  int_val = (VAL_3 != VAL_2)? int_val1: int_val2;
+  int_val = (VAL_6 != 10)? int_val1: int_val2;
+  int_val = (VAL_6 != 3)? int_val1: int_val2;
+  int_val = (VAL_6 != 4)? int_val1: int_val2;
+  int_val = (VAL_6 == 3)? int_val1: int_val2;
+  int_val = (VAL_6 == 4)? int_val1: int_val2;
+
+  TestStruct tsVar1 = {
+    .mA = 3,
+    .mB = int_val,
+    .mC[0 ... VAL_2 - 2] = int_val + 1,
+  };
+
+  TestStruct tsVar2 = {
+    .mA = 3,
+    .mB = int_val,
+    .mC[0 ... cint_val2 - 2] = int_val + 1,
+  };
+
+  TestStruct tsVar3 = {
+    .mA = 3,
+    .mB = int_val,
+    .mC[0 ... VAL_3 - VAL_3] = int_val + 1,
+    // CHECK-MESSAGES: :[[@LINE-1]]:21: warning: both sides of operator are equivalent
+  };
+
+  TestStruct tsVar4 = {
+    .mA = 3,
+    .mB = int_val,
+    .mC[0 ... 5 - 5] = int_val + 1,
+    // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: both sides of operator are equivalent
+  };
+
+  return 1 + int_val + sizeof(tsVar1) + sizeof(tsVar2) +
+         sizeof(tsVar3) + sizeof(tsVar4);
+}
+
+#define LOOP_DEFINE 1
+
+unsigned int testLoops(const unsigned int  arr1[LOOP_DEFINE])
+{
+  unsigned int localIndex;
+  for (localIndex = LOOP_DEFINE - 1; localIndex > 0; localIndex--)
+  {
+  }
+  for (localIndex = LOOP_DEFINE - 1; 10 > 10; localIndex--)
+  // CHECK-MESSAGES: :[[@LINE-1]]:41: warning: both sides of operator are equivalent
+  {
+  }
+
+  for (localIndex = LOOP_DEFINE - 1; LOOP_DEFINE > LOOP_DEFINE; localIndex--)
+  // CHECK-MESSAGES: :[[@LINE-1]]:50: warning: both sides of operator are equivalent
+  {
+  }
+
+  return localIndex;
+}
+
 template <int DX>
 int TestSimpleEquivalentDependent() {
   if (DX > 0 && DX > 0) return 1;

@llvmbot
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llvmbot commented Jan 7, 2025

@llvm/pr-subscribers-clang-tidy

Author: None (earnol)

Changes

This patch addresses situations when misc-redundant-expression checker provides excessive diagnostics for situations with different macros having the same value. In particular it addresses situations described in the initial report of #118885 are addressed. The situations which are popped inside discussion like if (A + B == B + A) for macros are not properly addressed by this patch.


Full diff: https://github.com/llvm/llvm-project/pull/121960.diff

2 Files Affected:

  • (modified) clang-tools-extra/clang-tidy/misc/RedundantExpressionCheck.cpp (+99-19)
  • (modified) clang-tools-extra/test/clang-tidy/checkers/misc/redundant-expression.cpp (+150)
diff --git a/clang-tools-extra/clang-tidy/misc/RedundantExpressionCheck.cpp b/clang-tools-extra/clang-tidy/misc/RedundantExpressionCheck.cpp
index fc35bc22c52e04..d6136c40d64cc8 100644
--- a/clang-tools-extra/clang-tidy/misc/RedundantExpressionCheck.cpp
+++ b/clang-tools-extra/clang-tidy/misc/RedundantExpressionCheck.cpp
@@ -139,10 +139,8 @@ static bool areEquivalentExpr(const Expr *Left, const Expr *Right) {
     return cast<BinaryOperator>(Left)->getOpcode() ==
            cast<BinaryOperator>(Right)->getOpcode();
   case Stmt::UnaryExprOrTypeTraitExprClass:
-    const auto *LeftUnaryExpr =
-        cast<UnaryExprOrTypeTraitExpr>(Left);
-    const auto *RightUnaryExpr =
-        cast<UnaryExprOrTypeTraitExpr>(Right);
+    const auto *LeftUnaryExpr = cast<UnaryExprOrTypeTraitExpr>(Left);
+    const auto *RightUnaryExpr = cast<UnaryExprOrTypeTraitExpr>(Right);
     if (LeftUnaryExpr->isArgumentType() && RightUnaryExpr->isArgumentType())
       return LeftUnaryExpr->getKind() == RightUnaryExpr->getKind() &&
              LeftUnaryExpr->getArgumentType() ==
@@ -699,7 +697,8 @@ static bool retrieveRelationalIntegerConstantExpr(
 
     Symbol = OverloadedOperatorExpr->getArg(IntegerConstantIsFirstArg ? 1 : 0);
     OperandExpr = OverloadedOperatorExpr;
-    Opcode = BinaryOperator::getOverloadedOpcode(OverloadedOperatorExpr->getOperator());
+    Opcode = BinaryOperator::getOverloadedOpcode(
+        OverloadedOperatorExpr->getOperator());
 
     if (!retrieveIntegerConstantExpr(Result, Id, Value, ConstExpr))
       return false;
@@ -728,7 +727,8 @@ static bool retrieveRelationalIntegerConstantExpr(
 }
 
 // Checks for expressions like (X == 4) && (Y != 9)
-static bool areSidesBinaryConstExpressions(const BinaryOperator *&BinOp, const ASTContext *AstCtx) {
+static bool areSidesBinaryConstExpressions(const BinaryOperator *&BinOp,
+                                           const ASTContext *AstCtx) {
   const auto *LhsBinOp = dyn_cast<BinaryOperator>(BinOp->getLHS());
   const auto *RhsBinOp = dyn_cast<BinaryOperator>(BinOp->getRHS());
 
@@ -747,6 +747,31 @@ static bool areSidesBinaryConstExpressions(const BinaryOperator *&BinOp, const A
   return false;
 }
 
+static bool
+areSidesBinaryConstExpressionsOrDefines(const BinaryOperator *&BinOp,
+                                        const ASTContext *AstCtx) {
+  if (areSidesBinaryConstExpressions(BinOp, AstCtx))
+    return true;
+
+  const auto *Lhs = BinOp->getLHS();
+  const auto *Rhs = BinOp->getRHS();
+
+  if (!Lhs || !Rhs)
+    return false;
+
+  auto IsDefineExpr = [AstCtx](const Expr *E) {
+    SourceRange Lsr = E->getSourceRange();
+    if (!Lsr.getBegin().isMacroID() || E->isValueDependent() ||
+        !E->isIntegerConstantExpr(*AstCtx))
+      return false;
+    return true;
+  };
+
+  if (IsDefineExpr(Lhs) || IsDefineExpr(Rhs))
+    return true;
+  return false;
+}
+
 // Retrieves integer constant subexpressions from binary operator expressions
 // that have two equivalent sides.
 // E.g.: from (X == 5) && (X == 5) retrieves 5 and 5.
@@ -785,7 +810,7 @@ static bool retrieveConstExprFromBothSides(const BinaryOperator *&BinOp,
 }
 
 static bool isSameRawIdentifierToken(const Token &T1, const Token &T2,
-                        const SourceManager &SM) {
+                                     const SourceManager &SM) {
   if (T1.getKind() != T2.getKind())
     return false;
   if (T1.isNot(tok::raw_identifier))
@@ -852,6 +877,58 @@ static bool areExprsMacroAndNonMacro(const Expr *&LhsExpr,
 
   return LhsLoc.isMacroID() != RhsLoc.isMacroID();
 }
+
+static bool areExprsSameMacroOrLiteral(const BinaryOperator *BinOp,
+                                       const ASTContext *Context) {
+
+  if (!BinOp)
+    return false;
+
+  const auto *Lhs = BinOp->getLHS();
+  const auto *Rhs = BinOp->getRHS();
+  const SourceManager &SM = Context->getSourceManager();
+
+  SourceRange Lsr = Lhs->getSourceRange();
+  SourceRange Rsr = Rhs->getSourceRange();
+  if (Lsr.getBegin().isMacroID()) {
+    // Left is macro so right macro too
+    if (Rsr.getBegin().isMacroID()) {
+      // Both sides are macros so they are same macro or literal
+      llvm::StringRef L = Lexer::getSourceText(
+          CharSourceRange::getTokenRange(Lsr), SM, LangOptions(), 0);
+      llvm::StringRef R = Lexer::getSourceText(
+          CharSourceRange::getTokenRange(Rsr), SM, LangOptions(), 0);
+      return L.compare(R) == 0;
+    }
+    // Left is macro but right is not so they are not same macro or literal
+    return false;
+  } else {
+    const IntegerLiteral *Lil = dyn_cast<IntegerLiteral>(Lhs);
+    const IntegerLiteral *Ril = dyn_cast<IntegerLiteral>(Rhs);
+    if (Lil && Ril) {
+      return Lil->getValue() == Ril->getValue();
+    }
+
+    const StringLiteral *LStrl = dyn_cast<StringLiteral>(Lhs);
+    const StringLiteral *RStrl = dyn_cast<StringLiteral>(Rhs);
+    if (Lil && Ril) {
+      llvm::StringRef L = Lexer::getSourceText(
+          CharSourceRange::getTokenRange(LStrl->getBeginLoc()), SM,
+          LangOptions(), 0);
+      llvm::StringRef R = Lexer::getSourceText(
+          CharSourceRange::getTokenRange(RStrl->getBeginLoc()), SM,
+          LangOptions(), 0);
+      return L.compare(R) == 0;
+    }
+
+    const CXXBoolLiteralExpr *Lbl = dyn_cast<CXXBoolLiteralExpr>(Lhs);
+    const CXXBoolLiteralExpr *Rbl = dyn_cast<CXXBoolLiteralExpr>(Rhs);
+    if (Lbl && Rbl) {
+      return Lbl->getValue() == Rbl->getValue();
+    }
+  }
+  return false;
+}
 } // namespace
 
 void RedundantExpressionCheck::registerMatchers(MatchFinder *Finder) {
@@ -1089,7 +1166,6 @@ static bool exprEvaluatesToSymbolic(BinaryOperatorKind Opcode, APSInt Value) {
          ((Opcode == BO_And || Opcode == BO_AndAssign) && ~Value == 0);
 }
 
-
 void RedundantExpressionCheck::checkBitwiseExpr(
     const MatchFinder::MatchResult &Result) {
   if (const auto *ComparisonOperator = Result.Nodes.getNodeAs<BinaryOperator>(
@@ -1134,8 +1210,8 @@ void RedundantExpressionCheck::checkBitwiseExpr(
                                      ConstExpr))
       return;
 
-    if((Value != 0 && ~Value != 0) || Sym->getExprLoc().isMacroID())
-        return;
+    if ((Value != 0 && ~Value != 0) || Sym->getExprLoc().isMacroID())
+      return;
 
     SourceLocation Loc = IneffectiveOperator->getOperatorLoc();
 
@@ -1276,17 +1352,21 @@ void RedundantExpressionCheck::check(const MatchFinder::MatchResult &Result) {
       return;
     }
 
-    if (areSidesBinaryConstExpressions(BinOp, Result.Context)) {
+    if (areSidesBinaryConstExpressionsOrDefines(BinOp, Result.Context)) {
       const Expr *LhsConst = nullptr, *RhsConst = nullptr;
       BinaryOperatorKind MainOpcode{}, SideOpcode{};
-
-      if (!retrieveConstExprFromBothSides(BinOp, MainOpcode, SideOpcode,
-                                          LhsConst, RhsConst, Result.Context))
-        return;
-
-      if (areExprsFromDifferentMacros(LhsConst, RhsConst, Result.Context) ||
-          areExprsMacroAndNonMacro(LhsConst, RhsConst))
-        return;
+      if (areSidesBinaryConstExpressions(BinOp, Result.Context)) {
+        if (!retrieveConstExprFromBothSides(BinOp, MainOpcode, SideOpcode,
+                                            LhsConst, RhsConst, Result.Context))
+          return;
+
+        if (areExprsFromDifferentMacros(LhsConst, RhsConst, Result.Context) ||
+            areExprsMacroAndNonMacro(LhsConst, RhsConst))
+          return;
+      } else {
+        if (!areExprsSameMacroOrLiteral(BinOp, Result.Context))
+          return;
+      }
     }
 
     diag(BinOp->getOperatorLoc(), "both sides of operator are equivalent");
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/redundant-expression.cpp b/clang-tools-extra/test/clang-tidy/checkers/misc/redundant-expression.cpp
index 7396d2dce76c43..75a73808900724 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/misc/redundant-expression.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/misc/redundant-expression.cpp
@@ -1,4 +1,5 @@
 // RUN: %check_clang_tidy %s misc-redundant-expression %t -- -- -fno-delayed-template-parsing -Wno-array-compare-cxx26
+// RUN: %check_clang_tidy %s misc-redundant-expression %t -- -- -fno-delayed-template-parsing -Wno-array-compare-cxx26 -DTEST_MACRO
 
 typedef __INT64_TYPE__ I64;
 
@@ -91,6 +92,155 @@ int TestSimpleEquivalent(int X, int Y) {
   return 0;
 }
 
+#ifndef TEST_MACRO
+#define VAL_1 2
+#define VAL_3 3
+#else
+#define VAL_1 3
+#define VAL_3 2
+#endif
+
+#define VAL_2 2
+
+#ifndef TEST_MACRO
+#define VAL_4 2 + 1
+#define VAL_6 3 + 1
+#else
+#define VAL_4 3 + 1
+#define VAL_6 2 + 1
+#endif
+
+#define VAL_5 2 + 1
+
+struct TestStruct
+{
+  int mA;
+  int mB;
+  int mC[10];
+};
+
+int TestDefineEquivalent() {
+
+  int int_val1 = 3;
+  int int_val2 = 4;
+  int int_val = 0;
+  const int cint_val2 = 4;
+
+  // Cases which should not be reported
+  if (VAL_1 != VAL_2)  return 0;
+  if (VAL_3 != VAL_2)  return 0;
+  if (VAL_1 == VAL_2)  return 0;
+  if (VAL_3 == VAL_2)  return 0;
+  if (VAL_1 >= VAL_2)  return 0;
+  if (VAL_3 >= VAL_2)  return 0;
+  if (VAL_1 <= VAL_2)  return 0;
+  if (VAL_3 <= VAL_2)  return 0;
+  if (VAL_1 < VAL_2)  return 0;
+  if (VAL_3 < VAL_2)  return 0;
+  if (VAL_1 > VAL_2)  return 0;
+  if (VAL_3 > VAL_2)  return 0;
+
+  if (VAL_4 != VAL_5)  return 0;
+  if (VAL_6 != VAL_5)  return 0;
+  if (VAL_6 == VAL_5)  return 0;
+  if (VAL_4 >= VAL_5)  return 0;
+  if (VAL_6 >= VAL_5)  return 0;
+  if (VAL_4 <= VAL_5)  return 0;
+  if (VAL_6 <= VAL_5)  return 0;
+  if (VAL_4 > VAL_5)  return 0;
+  if (VAL_6 > VAL_5)  return 0;
+  if (VAL_4 < VAL_5)  return 0;
+  if (VAL_6 < VAL_5)  return 0;
+
+  if (VAL_1 != 2)  return 0;
+  if (VAL_3 == 3)  return 0;
+
+  if (VAL_1 >= VAL_1)  return 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: both sides of operator are equivalent
+  if (VAL_2 <= VAL_2)  return 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: both sides of operator are equivalent
+  if (VAL_3 > VAL_3)  return 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: both sides of operator are equivalent
+  if (VAL_4 < VAL_4)  return 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: both sides of operator are equivalent
+  if (VAL_6 == VAL_6) return 2;
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: both sides of operator are equivalent
+  if (VAL_5 != VAL_5) return 2;
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: both sides of operator are equivalent
+
+  if (1 >= 1)  return 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both sides of operator are equivalent
+  if (0xFF <= 0xFF)  return 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: both sides of operator are equivalent
+  if (042 > 042)  return 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:11: warning: both sides of operator are equivalent
+
+  int_val = (VAL_6 == VAL_6)?int_val1: int_val2;
+  // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: both sides of operator are equivalent
+  int_val = (042 > 042)?int_val1: int_val2;
+  // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: both sides of operator are equivalent
+
+
+  // Ternary operator cases which should not be reported
+  int_val = (VAL_4 == VAL_5)? int_val1: int_val2;
+  int_val = (VAL_3 != VAL_2)? int_val1: int_val2;
+  int_val = (VAL_6 != 10)? int_val1: int_val2;
+  int_val = (VAL_6 != 3)? int_val1: int_val2;
+  int_val = (VAL_6 != 4)? int_val1: int_val2;
+  int_val = (VAL_6 == 3)? int_val1: int_val2;
+  int_val = (VAL_6 == 4)? int_val1: int_val2;
+
+  TestStruct tsVar1 = {
+    .mA = 3,
+    .mB = int_val,
+    .mC[0 ... VAL_2 - 2] = int_val + 1,
+  };
+
+  TestStruct tsVar2 = {
+    .mA = 3,
+    .mB = int_val,
+    .mC[0 ... cint_val2 - 2] = int_val + 1,
+  };
+
+  TestStruct tsVar3 = {
+    .mA = 3,
+    .mB = int_val,
+    .mC[0 ... VAL_3 - VAL_3] = int_val + 1,
+    // CHECK-MESSAGES: :[[@LINE-1]]:21: warning: both sides of operator are equivalent
+  };
+
+  TestStruct tsVar4 = {
+    .mA = 3,
+    .mB = int_val,
+    .mC[0 ... 5 - 5] = int_val + 1,
+    // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: both sides of operator are equivalent
+  };
+
+  return 1 + int_val + sizeof(tsVar1) + sizeof(tsVar2) +
+         sizeof(tsVar3) + sizeof(tsVar4);
+}
+
+#define LOOP_DEFINE 1
+
+unsigned int testLoops(const unsigned int  arr1[LOOP_DEFINE])
+{
+  unsigned int localIndex;
+  for (localIndex = LOOP_DEFINE - 1; localIndex > 0; localIndex--)
+  {
+  }
+  for (localIndex = LOOP_DEFINE - 1; 10 > 10; localIndex--)
+  // CHECK-MESSAGES: :[[@LINE-1]]:41: warning: both sides of operator are equivalent
+  {
+  }
+
+  for (localIndex = LOOP_DEFINE - 1; LOOP_DEFINE > LOOP_DEFINE; localIndex--)
+  // CHECK-MESSAGES: :[[@LINE-1]]:50: warning: both sides of operator are equivalent
+  {
+  }
+
+  return localIndex;
+}
+
 template <int DX>
 int TestSimpleEquivalentDependent() {
   if (DX > 0 && DX > 0) return 1;

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@EugeneZelenko EugeneZelenko left a comment

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Please mention changes in Release Notes.

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@PiotrZSL PiotrZSL left a comment

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Overall, may require some small work to make sure that code is straightforward and simple.
As for functionality part, still has some gaps or redundant parts, but that is not a blocker.

Please try to refactor your changes to be simpler, like function names to actually say what they doing.
Missing changes in release notes and check documentation

CharSourceRange::getTokenRange(Lsr), SM, LangOptions(), 0);
llvm::StringRef R = Lexer::getSourceText(
CharSourceRange::getTokenRange(Rsr), SM, LangOptions(), 0);
return L.compare(R) == 0;
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what with

#define getX(x) x
int var = getX(1) > getX( 1);

In such case string compare won't work.

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@earnol earnol Jan 13, 2025

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I agree, but in this case the both sides are not literally the same.
I propose to make it space for improvement.
The way it is currently it will find copy paste errors which is good.
Update: I think it is a good idea. Implemented.

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Documentation and release notes updated.

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