// RUN: %check_clang_tidy %s misc-redundant-expression %t -- -- -fno-delayed-template-parsing -Wno-array-compare-cxx26 typedef __INT64_TYPE__ I64; struct Point { int x; int y; int a[5]; } P; extern Point P1; extern Point P2; extern int foo(int x); extern int bar(int x); extern int bat(int x, int y); int TestSimpleEquivalent(int X, int Y) { if (X - X) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both sides of operator are equivalent [misc-redundant-expression] if (X / X) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both sides of operator are equivalent if (X % X) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both sides of operator are equivalent if (X & X) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both sides of operator are equivalent if (X | X) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both sides of operator are equivalent if (X ^ X) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both sides of operator are equivalent if (X < X) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both sides of operator are equivalent if (X <= X) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both sides of operator are equivalent if (X > X) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both sides of operator are equivalent if (X >= X) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both sides of operator are equivalent if (X && X) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both sides of operator are equivalent if (X || X) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both sides of operator are equivalent if (X != (((X)))) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both sides of operator are equivalent if (X + 1 == X + 1) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: both sides of operator are equivalent if (X + 1 != X + 1) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: both sides of operator are equivalent if (X + 1 <= X + 1) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: both sides of operator are equivalent if (X + 1 >= X + 1) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: both sides of operator are equivalent if ((X != 1 || Y != 1) && (X != 1 || Y != 1)) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:26: warning: both sides of operator are equivalent if (P.a[X - P.x] != P.a[X - P.x]) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: both sides of operator are equivalent if ((int)X < (int)X) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: both sides of operator are equivalent if (int(X) < int(X)) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: both sides of operator are equivalent if ( + "dummy" == + "dummy") return 1; // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: both sides of operator are equivalent if (L"abc" == L"abc") return 1; // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: both sides of operator are equivalent if (foo(0) - 2 < foo(0) - 2) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: both sides of operator are equivalent if (foo(bar(0)) < (foo(bar((0))))) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: both sides of operator are equivalent if (P1.x < P2.x && P1.x < P2.x) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: both sides of operator are equivalent if (P2.a[P1.x + 2] < P2.x && P2.a[(P1.x) + (2)] < (P2.x)) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:29: warning: both sides of operator are equivalent if (X && Y && X) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: operator has equivalent nested operands if (X || (Y || X)) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: operator has equivalent nested operands if ((X ^ Y) ^ (Y ^ X)) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:15: warning: operator has equivalent nested operands return 0; } template int TestSimpleEquivalentDependent() { if (DX > 0 && DX > 0) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: both sides of operator are equivalent return 0; } int Valid(int X, int Y) { if (X != Y) return 1; if (X == Y + 0) return 1; if (P.x == P.y) return 1; if (P.a[P.x] < P.a[P.y]) return 1; if (P.a[0] < P.a[1]) return 1; if (P.a[0] < P.a[0ULL]) return 1; if (0 < 0ULL) return 1; if ((int)0 < (int)0ULL) return 1; if (++X != ++X) return 1; if (P.a[X]++ != P.a[X]++) return 1; if (P.a[X++] != P.a[X++]) return 1; if (X && X++ && X) return 1; if ("abc" == "ABC") return 1; if (foo(bar(0)) < (foo(bat(0, 1)))) return 1; return 0; } #define COND_OP_MACRO 9 #define COND_OP_OTHER_MACRO 9 #define COND_OP_THIRD_MACRO COND_OP_MACRO int TestConditional(int x, int y) { int k = 0; k += (y < 0) ? x : x; // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: 'true' and 'false' expressions are equivalent k += (y < 0) ? x + 1 : x + 1; // CHECK-MESSAGES: :[[@LINE-1]]:24: warning: 'true' and 'false' expressions are equivalent k += (y < 0) ? COND_OP_MACRO : COND_OP_MACRO; // CHECK-MESSAGES: :[[@LINE-1]]:32: warning: 'true' and 'false' expressions are equivalent k += (y < 0) ? COND_OP_MACRO + COND_OP_OTHER_MACRO : COND_OP_MACRO + COND_OP_OTHER_MACRO; // CHECK-MESSAGES: :[[@LINE-1]]:54: warning: 'true' and 'false' expressions are equivalent // Do not match for conditional operators with a macro and a const. k += (y < 0) ? COND_OP_MACRO : 9; // Do not match for conditional operators with expressions from different macros. k += (y < 0) ? COND_OP_MACRO : COND_OP_OTHER_MACRO; // Do not match for conditional operators when a macro is defined to another macro k += (y < 0) ? COND_OP_MACRO : COND_OP_THIRD_MACRO; #undef COND_OP_THIRD_MACRO #define COND_OP_THIRD_MACRO 8 k += (y < 0) ? COND_OP_MACRO : COND_OP_THIRD_MACRO; #undef COND_OP_THIRD_MACRO k += (y < 0) ? sizeof(I64) : sizeof(I64); // CHECK-MESSAGES: :[[@LINE-1]]:30: warning: 'true' and 'false' expressions are equivalent k += (y < 0) ? sizeof(TestConditional(k,y)) : sizeof(TestConditional(k,y)); // CHECK-MESSAGES: :[[@LINE-1]]:47: warning: 'true' and 'false' expressions are equivalent // No warning if the expression arguments are different. k += (y < 0) ? sizeof(TestConditional(k,y)) : sizeof(Valid(k,y)); return k; } #undef COND_OP_MACRO #undef COND_OP_OTHER_MACRO // Overloaded operators that compare two instances of a struct. struct MyStruct { int x; bool operator==(const MyStruct& rhs) const {return this->x == rhs.x; } // not modifing bool operator>=(const MyStruct& rhs) const { return this->x >= rhs.x; } // not modifing bool operator<=(MyStruct& rhs) const { return this->x <= rhs.x; } bool operator&&(const MyStruct& rhs){ this->x++; return this->x && rhs.x; } } Q; bool operator!=(const MyStruct& lhs, const MyStruct& rhs) { return lhs.x == rhs.x; } // not modifing bool operator<(const MyStruct& lhs, const MyStruct& rhs) { return lhs.x < rhs.x; } // not modifing bool operator>(const MyStruct& lhs, MyStruct& rhs) { rhs.x--; return lhs.x > rhs.x; } bool operator||(MyStruct& lhs, const MyStruct& rhs) { lhs.x++; return lhs.x || rhs.x; } struct MyStruct1 { bool x; MyStruct1(bool x) : x(x) {}; operator bool() { return x; } }; MyStruct1 operator&&(const MyStruct1& lhs, const MyStruct1& rhs) { return lhs.x && rhs.x; } MyStruct1 operator||(MyStruct1& lhs, MyStruct1& rhs) { return lhs.x && rhs.x; } bool TestOverloadedOperator(MyStruct& S) { if (S == Q) return false; if (S <= S) return false; if (S && S) return false; if (S > S) return false; if (S || S) return false; if (S == S) return true; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both sides of overloaded operator are equivalent if (S < S) return true; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both sides of overloaded operator are equivalent if (S != S) return true; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both sides of overloaded operator are equivalent if (S >= S) return true; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: both sides of overloaded operator are equivalent MyStruct1 U(false); MyStruct1 V(true); // valid because the operator is not const if ((U || V) || U) return true; if (U && V && U && V) return true; // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: overloaded operator has equivalent nested operands return true; } #define LT(x, y) (void)((x) < (y)) #define COND(x, y, z) ((x)?(y):(z)) #define EQUALS(x, y) (x) == (y) int TestMacro(int X, int Y) { LT(0, 0); LT(1, 0); LT(X, X); LT(X+1, X + 1); COND(X < Y, X, X); EQUALS(Q, Q); return 0; } int TestFalsePositive(int* A, int X, float F) { // Produced by bison. X = A[(2) - (2)]; X = A['a' - 'a']; // Testing NaN. if (F != F && F == F) return 1; return 0; } int TestBannedMacros() { #define EAGAIN 3 #define NOT_EAGAIN 3 if (EAGAIN == 0 | EAGAIN == 0) return 0; if (NOT_EAGAIN == 0 | NOT_EAGAIN == 0) return 0; // CHECK-MESSAGES: :[[@LINE-1]]:23: warning: both sides of operator are equivalent return 0; } struct MyClass { static const int Value = 42; }; template void TemplateCheck() { static_assert(T::Value == U::Value, "should be identical"); static_assert(T::Value == T::Value, "should be identical"); // CHECK-MESSAGES: :[[@LINE-1]]:26: warning: both sides of operator are equivalent } void TestTemplate() { TemplateCheck(); } int TestArithmetic(int X, int Y) { if (X + 1 == X) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: logical expression is always false if (X + 1 != X) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: logical expression is always true if (X - 1 == X) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: logical expression is always false if (X - 1 != X) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: logical expression is always true if (X + 1LL == X) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:15: warning: logical expression is always false if (X + 1ULL == X) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:16: warning: logical expression is always false if (X == X + 1) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: logical expression is always false if (X != X + 1) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: logical expression is always true if (X == X - 1) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: logical expression is always false if (X != X - 1) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: logical expression is always true if (X != X - 1U) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: logical expression is always true if (X != X - 1LL) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: logical expression is always true if ((X+X) != (X+X) - 1) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: logical expression is always true if (X + 1 == X + 2) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: logical expression is always false if (X + 1 != X + 2) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: logical expression is always true if (X - 1 == X - 2) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: logical expression is always false if (X - 1 != X - 2) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: logical expression is always true if (X + 1 == X - -1) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: logical expression is always true if (X + 1 != X - -1) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: logical expression is always false if (X + 1 == X - -2) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: logical expression is always false if (X + 1 != X - -2) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: logical expression is always true if (X + 1 == X - (~0)) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: logical expression is always true if (X + 1 == X - (~0U)) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: logical expression is always true if (X + 1 == X - (~0ULL)) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: logical expression is always true // Should not match. if (X + 0.5 == X) return 1; if (X + 1 == Y) return 1; if (X + 1 == Y + 1) return 1; if (X + 1 == Y + 2) return 1; return 0; } int TestBitwise(int X, int Y) { if ((X & 0xFF) == 0xF00) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: logical expression is always false if ((X & 0xFF) != 0xF00) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: logical expression is always true if ((X | 0xFF) == 0xF00) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: logical expression is always false if ((X | 0xFF) != 0xF00) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: logical expression is always true if ((X | 0xFFULL) != 0xF00) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:21: warning: logical expression is always true if ((X | 0xFF) != 0xF00ULL) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: logical expression is always true if ((0xFF & X) == 0xF00) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: logical expression is always false if ((0xFF & X) != 0xF00) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: logical expression is always true if ((0xFF & X) == 0xF00) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: logical expression is always false if ((0xFF & X) != 0xF00) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: logical expression is always true if ((0xFFLL & X) == 0xF00) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: logical expression is always false if ((0xFF & X) == 0xF00ULL) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: logical expression is always false return 0; } // Overloaded operators that compare an instance of a struct and an integer // constant. struct S { S() { x = 1; } int x; // Overloaded comparison operators without any possible side effect. bool operator==(const int &i) const { return x == i; } // not modifying bool operator!=(int i) const { return x != i; } // not modifying bool operator>(const int &i) const { return x > i; } // not modifying bool operator<(int i) const { return x < i; } // not modifying }; bool operator<=(const S &s, int i) { return s.x <= i; } // not modifying bool operator>=(const S &s, const int &i) { return s.x >= i; } // not modifying bool operator==(int i, const S &s) { return s == i; } // not modifying bool operator<(const int &i, const S &s) { return s > i; } // not modifying bool operator<=(const int &i, const S &s) { return s >= i; } // not modifying bool operator>(const int &i, const S &s) { return s < i; } // not modifying struct S2 { S2() { x = 1; } int x; // Overloaded comparison operators that are able to modify their params. bool operator==(const int &i) { this->x++; return x == i; } bool operator!=(int i) { return x != i; } bool operator>(const int &i) { return x > i; } bool operator<(int i) { this->x--; return x < i; } }; bool operator>=(S2 &s, const int &i) { return s.x >= i; } bool operator<=(S2 &s, int i) { s.x++; return s.x <= i; } int TestLogical(int X, int Y){ #define CONFIG 0 if (CONFIG && X) return 1; #undef CONFIG #define CONFIG 1 if (CONFIG || X) return 1; #undef CONFIG if (X == 10 && X != 10) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:15: warning: logical expression is always false if (X == 10 && (X != 10)) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:15: warning: logical expression is always false if (X == 10 && !(X == 10)) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:15: warning: logical expression is always false if (!(X != 10) && !(X == 10)) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: logical expression is always false if (X == 10ULL && X != 10ULL) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: logical expression is always false if (!(X != 10U) && !(X == 10)) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: logical expression is always false if (!(X != 10LL) && !(X == 10)) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: logical expression is always false if (!(X != 10ULL) && !(X == 10)) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:21: warning: logical expression is always false if (X == 0 && X) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: logical expression is always false if (X != 0 && !X) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: logical expression is always false if (X && !X) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: logical expression is always false if (X && !!X) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: equivalent expression on both sides of logical operator if (X != 0 && X) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: equivalent expression on both sides of logical operator if (X != 0 && !!X) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: equivalent expression on both sides of logical operator if (X == 0 && !X) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: equivalent expression on both sides of logical operator // Should not match. if (X == 10 && Y == 10) return 1; if (X != 10 && X != 12) return 1; if (X == 10 || X == 12) return 1; if (!X && !Y) return 1; if (!X && Y) return 1; if (!X && Y == 0) return 1; if (X == 10 && Y != 10) return 1; // Test for overloaded operators with constant params. S s1; if (s1 == 1 && s1 == 1) return true; // CHECK-MESSAGES: :[[@LINE-1]]:15: warning: equivalent expression on both sides of logical operator if (s1 == 1 || s1 != 1) return true; // CHECK-MESSAGES: :[[@LINE-1]]:15: warning: logical expression is always true if (s1 > 1 && s1 < 1) return true; // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: logical expression is always false if (s1 >= 1 || s1 <= 1) return true; // CHECK-MESSAGES: :[[@LINE-1]]:15: warning: logical expression is always true if (s1 >= 2 && s1 <= 0) return true; // CHECK-MESSAGES: :[[@LINE-1]]:15: warning: logical expression is always false // Same test as above but with swapped LHS/RHS on one side of the logical operator. if (1 == s1 && s1 == 1) return true; // CHECK-MESSAGES: :[[@LINE-1]]:15: warning: equivalent expression on both sides of logical operator if (1 == s1 || s1 != 1) return true; // CHECK-MESSAGES: :[[@LINE-1]]:15: warning: logical expression is always true if (1 < s1 && s1 < 1) return true; // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: logical expression is always false if (1 <= s1 || s1 <= 1) return true; // CHECK-MESSAGES: :[[@LINE-1]]:15: warning: logical expression is always true if (2 < s1 && 0 > s1) return true; // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: logical expression is always false // Test for absence of false positives (issue #54011). if (s1 == 1 || s1 == 2) return true; if (s1 > 1 && s1 < 3) return true; if (s1 >= 2 || s1 <= 0) return true; // Test for overloaded operators that may modify their params. S2 s2; if (s2 == 1 || s2 != 1) return true; if (s2 == 1 || s2 == 1) return true; if (s2 > 1 && s2 < 1) return true; if (s2 >= 1 || s2 <= 1) return true; } int TestRelational(int X, int Y) { if (X == 10 && X > 10) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:15: warning: logical expression is always false if (X == 10 && X < 10) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:15: warning: logical expression is always false if (X < 10 && X > 10) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: logical expression is always false if (X <= 10 && X > 10) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:15: warning: logical expression is always false if (X < 10 && X >= 10) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: logical expression is always false if (X < 10 && X == 10) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: logical expression is always false if (X > 5 && X <= 5) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: logical expression is always false if (X > -5 && X <= -5) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: logical expression is always false if (X < 10 || X >= 10) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: logical expression is always true if (X <= 10 || X > 10) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:15: warning: logical expression is always true if (X <= 10 || X >= 11) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:15: warning: logical expression is always true if (X != 7 || X != 14) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: logical expression is always true if (X == 7 || X != 5) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: expression is redundant if (X != 7 || X == 7) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: logical expression is always true if (X < 7 && X < 6) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: expression is redundant if (X < 7 && X < 7) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: both sides of operator are equivalent if (X < 7 && X < 8) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: expression is redundant if (X < 7 && X <= 5) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: expression is redundant if (X < 7 && X <= 6) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: equivalent expression on both sides of logical operator if (X < 7 && X <= 7) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: expression is redundant if (X < 7 && X <= 8) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: expression is redundant if (X <= 7 && X < 6) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: expression is redundant if (X <= 7 && X < 7) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: expression is redundant if (X <= 7 && X < 8) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: equivalent expression on both sides of logical operator if (X >= 7 && X > 6) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: equivalent expression on both sides of logical operator if (X >= 7 && X > 7) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: expression is redundant if (X >= 7 && X > 8) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: expression is redundant if (X <= 7 && X <= 5) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: expression is redundant if (X <= 7 && X <= 6) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: expression is redundant if (X <= 7 && X <= 7) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: both sides of operator are equivalent if (X <= 7 && X <= 8) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: expression is redundant if (X == 11 && X > 10) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: expression is redundant if (X == 11 && X < 12) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: expression is redundant if (X > 10 && X == 11) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: expression is redundant if (X < 12 && X == 11) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: expression is redundant if (X != 11 && X == 42) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: expression is redundant if (X != 11 && X > 11) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: expression is redundant if (X != 11 && X < 11) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: expression is redundant if (X != 11 && X < 8) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: expression is redundant if (X != 11 && X > 14) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: expression is redundant if (X < 7 || X < 6) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: expression is redundant if (X < 7 || X < 7) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: both sides of operator are equivalent if (X < 7 || X < 8) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: expression is redundant if (X > 7 || X > 6) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: expression is redundant if (X > 7 || X > 7) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: both sides of operator are equivalent if (X > 7 || X > 8) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: expression is redundant // Should not match. if (X < 10 || X > 12) return 1; if (X > 10 && X < 12) return 1; if (X < 10 || X >= 12) return 1; if (X > 10 && X <= 12) return 1; if (X <= 10 || X > 12) return 1; if (X >= 10 && X < 12) return 1; if (X <= 10 || X >= 12) return 1; if (X >= 10 && X <= 12) return 1; if (X >= 10 && X <= 11) return 1; if (X >= 10 && X < 11) return 1; if (X > 10 && X <= 11) return 1; if (X > 10 && X != 11) return 1; if (X >= 10 && X <= 10) return 1; if (X <= 10 && X >= 10) return 1; if (X < 0 || X > 0) return 1; } int TestRelationalMacros(int X){ #define SOME_MACRO 3 #define SOME_MACRO_SAME_VALUE 3 #define SOME_OTHER_MACRO 9 // Do not match for redundant relational macro expressions that can be // considered intentional, and for some particular values, non redundant. // Test cases for expressions with the same macro on both sides. if (X < SOME_MACRO && X > SOME_MACRO) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:22: warning: logical expression is always false if (X < SOME_MACRO && X == SOME_MACRO) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:22: warning: logical expression is always false if (X < SOME_MACRO || X >= SOME_MACRO) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:22: warning: logical expression is always true if (X <= SOME_MACRO || X > SOME_MACRO) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:23: warning: logical expression is always true if (X != SOME_MACRO && X > SOME_MACRO) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: expression is redundant if (X != SOME_MACRO && X < SOME_MACRO) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: expression is redundant // Test cases for two different macros. if (X < SOME_MACRO && X > SOME_OTHER_MACRO) return 1; if (X != SOME_MACRO && X >= SOME_OTHER_MACRO) return 1; if (X != SOME_MACRO && X != SOME_OTHER_MACRO) return 1; if (X == SOME_MACRO || X == SOME_MACRO_SAME_VALUE) return 1; if (X == SOME_MACRO || X <= SOME_MACRO_SAME_VALUE) return 1; if (X == SOME_MACRO || X > SOME_MACRO_SAME_VALUE) return 1; if (X < SOME_MACRO && X <= SOME_OTHER_MACRO) return 1; if (X == SOME_MACRO && X > SOME_OTHER_MACRO) return 1; if (X == SOME_MACRO && X != SOME_OTHER_MACRO) return 1; if (X == SOME_MACRO && X != SOME_MACRO_SAME_VALUE) return 1; if (X == SOME_MACRO_SAME_VALUE && X == SOME_MACRO ) return 1; // Test cases for a macro and a const. if (X < SOME_MACRO && X > 9) return 1; if (X != SOME_MACRO && X >= 9) return 1; if (X != SOME_MACRO && X != 9) return 1; if (X == SOME_MACRO || X == 3) return 1; if (X == SOME_MACRO || X <= 3) return 1; if (X < SOME_MACRO && X <= 9) return 1; if (X == SOME_MACRO && X != 9) return 1; if (X == SOME_MACRO && X == 9) return 1; #undef SOME_OTHER_MACRO #undef SOME_MACRO_SAME_VALUE #undef SOME_MACRO return 0; } int TestValidExpression(int X) { if (X - 1 == 1 - X) return 1; if (2 * X == X) return 1; if ((X << 1) == X) return 1; return 0; } enum Color { Red, Yellow, Green }; int TestRelationalWithEnum(enum Color C) { if (C == Red && C == Yellow) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:16: warning: logical expression is always false if (C == Red && C != Red) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:16: warning: logical expression is always false if (C != Red || C != Yellow) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:16: warning: logical expression is always true // Should not match. if (C == Red || C == Yellow) return 1; if (C != Red && C != Yellow) return 1; return 0; } template int TestRelationalTemplated(int X) { // This test causes a corner case with |isIntegerConstantExpr| where the type // is dependent. There is an assert failing when evaluating // sizeof(). if (sizeof(T) == 4 || sizeof(T) == 8) return 1; if (X + 0 == -X) return 1; if (X + 0 < X) return 1; return 0; } int TestWithSignedUnsigned(int X) { if (X + 1 == X + 1ULL) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: logical expression is always true if ((X & 0xFFU) == 0xF00) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: logical expression is always false if ((X & 0xFF) == 0xF00U) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: logical expression is always false if ((X & 0xFFU) == 0xF00U) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: logical expression is always false return 0; } int TestWithLong(int X, I64 Y) { if (X + 0ULL == -X) return 1; if (Y + 0 == -Y) return 1; if (Y <= 10 && X >= 10LL) return 1; if (Y <= 10 && X >= 10ULL) return 1; if (X <= 10 || X > 12LL) return 1; if (X <= 10 || X > 12ULL) return 1; if (Y <= 10 || Y > 12) return 1; return 0; } int TestWithMinMaxInt(int X) { if (X <= X + 0xFFFFFFFFU) return 1; if (X <= X + 0x7FFFFFFF) return 1; if (X <= X + 0x80000000) return 1; if (X <= 0xFFFFFFFFU && X > 0) return 1; if (X <= 0xFFFFFFFFU && X > 0U) return 1; if (X + 0x80000000 == X - 0x80000000) return 1; // CHECK-MESSAGES: :[[@LINE-1]]:22: warning: logical expression is always true if (X > 0x7FFFFFFF || X < ((-0x7FFFFFFF)-1)) return 1; if (X <= 0x7FFFFFFF && X >= ((-0x7FFFFFFF)-1)) return 1; return 0; } #define FLAG1 1 #define FLAG2 2 #define FLAG3 4 #define FLAGS (FLAG1 | FLAG2 | FLAG3) #define NOTFLAGS !(FLAG1 | FLAG2 | FLAG3) int TestOperatorConfusion(int X, int Y, long Z) { // Ineffective & expressions. Y = (Y << 8) & 0xff; // CHECK-MESSAGES: :[[@LINE-1]]:16: warning: ineffective bitwise and operation Y = (Y << 12) & 0xfff; // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: ineffective bitwise and Y = (Y << 12) & 0xff; // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: ineffective bitwise and Y = (Y << 8) & 0x77; // CHECK-MESSAGES: :[[@LINE-1]]:16: warning: ineffective bitwise and Y = (Y << 5) & 0x11; // CHECK-MESSAGES: :[[@LINE-1]]:16: warning: ineffective bitwise and // Tests for unmatched types Z = (Z << 8) & 0xff; // CHECK-MESSAGES: :[[@LINE-1]]:16: warning: ineffective bitwise and operation Y = (Y << 12) & 0xfffL; // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: ineffective bitwise and Z = (Y << 12) & 0xffLL; // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: ineffective bitwise and Y = (Z << 8L) & 0x77L; // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: ineffective bitwise and Y = (Y << 8) & 0; // CHECK-MESSAGES: :[[@LINE-1]]:16: warning: ineffective bitwise and Y = (Y << 8) & -1; // Effective expressions. Do not check. Y = (Y << 4) & 0x15; Y = (Y << 3) & 0x250; Y = (Y << 9) & 0xF33; int K = !(1 | 2 | 4); // CHECK-MESSAGES: :[[@LINE-1]]:11: warning: ineffective logical negation operator used; did you mean '~'? // CHECK-FIXES: {{^}} int K = ~(1 | 2 | 4);{{$}} K = !(FLAG1 & FLAG2 & FLAG3); // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: ineffective logical negation operator // CHECK-FIXES: {{^}} K = ~(FLAG1 & FLAG2 & FLAG3);{{$}} K = !(3 | 4); // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: ineffective logical negation operator // CHECK-FIXES: {{^}} K = ~(3 | 4);{{$}} int NotFlags = !FLAGS; // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: ineffective logical negation operator // CHECK-FIXES: {{^}} int NotFlags = ~FLAGS;{{$}} NotFlags = NOTFLAGS; // CHECK-MESSAGES: :[[@LINE-1]]:14: warning: ineffective logical negation operator return !(1 | 2 | 4); // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: ineffective logical negation operator // CHECK-FIXES: {{^}} return ~(1 | 2 | 4);{{$}} } template int TestOperatorConfusionDependent(int Y) { int r1 = (Y << Shift) & 0xff; int r2 = (Y << 8) & Mask; } #undef FLAG1 #undef FLAG2 #undef FLAG3 namespace no_crash { struct Foo {}; bool operator<(const Foo&, const Foo&); template struct Bar { static const Foo &GetFoo(); static bool Test(const T & maybe_foo, const Foo& foo) { return foo < GetFoo() && foo < maybe_foo; } }; template struct Bar2 { static_assert((... && (sizeof(Values) > 0)) == (... && (sizeof(Values) > 0))); // FIXME: It's not clear that we should be diagnosing this. The `&&` operator // here is unresolved and could resolve to an overloaded operator that might // have side-effects on its operands. For other constructs with the same // property (eg, the `S2` cases above) we suppress this diagnostic. This // started failing when Clang started properly modeling the fold-expression as // containing an unresolved operator name. // FIXME-MESSAGES: :[[@LINE-1]]:47: warning: both sides of operator are equivalent [misc-redundant-expression] }; } // namespace no_crash int TestAssignSideEffect(int i) { int k = i; if ((k = k + 1) != 1 || (k = k + 1) != 2) return 0; if ((k = foo(0)) != 1 || (k = foo(0)) != 2) return 1; return 2; } namespace PR63096 { struct alignas(sizeof(int)) X { int x; }; static_assert(alignof(X) == sizeof(X)); static_assert(sizeof(X) == sizeof(X)); // CHECK-MESSAGES: :[[@LINE-1]]:25: warning: both sides of operator are equivalent } namespace PR35857 { void test() { int x = 0; int y = 0; decltype(x + y - (x + y)) z = 10; } }