/* * Cppcheck - A tool for static C/C++ code analysis * Copyright (C) 2007-2014 Daniel Marjamäki and Cppcheck team. * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see . */ #include "tokenize.h" #include "checkcondition.h" #include "testsuite.h" #include extern std::ostringstream errout; class TestCondition : public TestFixture { public: TestCondition() : TestFixture("TestCondition") { } private: void run() { TEST_CASE(assignAndCompare); // assignment and comparison don't match TEST_CASE(mismatchingBitAnd); // overlapping bitmasks TEST_CASE(compare); // mismatching LHS/RHS in comparison TEST_CASE(multicompare); // mismatching comparisons TEST_CASE(duplicateIf); // duplicate conditions in if and else-if TEST_CASE(invalidMissingSemicolon); // crash as of #5867 TEST_CASE(incorrectLogicOperator1); TEST_CASE(incorrectLogicOperator2); TEST_CASE(incorrectLogicOperator3); TEST_CASE(incorrectLogicOperator4); TEST_CASE(incorrectLogicOperator5); // complex expressions TEST_CASE(incorrectLogicOperator6); // char literals TEST_CASE(incorrectLogicOperator7); // opposite expressions: (expr || !expr) TEST_CASE(secondAlwaysTrueFalseWhenFirstTrueError); TEST_CASE(incorrectLogicOp_condSwapping); TEST_CASE(modulo); TEST_CASE(oppositeInnerCondition); TEST_CASE(clarifyCondition1); // if (a = b() < 0) TEST_CASE(clarifyCondition2); // if (a & b == c) TEST_CASE(clarifyCondition3); // if (! a & b) TEST_CASE(clarifyCondition4); // ticket #3110 TEST_CASE(clarifyCondition5); // #3609 CWinTraits.. TEST_CASE(clarifyCondition6); // #3818 } void check(const char code[], bool validate=true, const char* filename = "test.cpp") { // Clear the error buffer.. errout.str(""); Settings settings; settings.addEnabled("style"); settings.addEnabled("warning"); CheckCondition checkCondition; // Tokenize.. Tokenizer tokenizer(&settings, this); std::istringstream istr(code); tokenizer.tokenize(istr, filename); checkCondition.runChecks(&tokenizer, &settings, this); const std::string str1(tokenizer.tokens()->stringifyList(0,true)); tokenizer.simplifyTokenList2(); const std::string str2(tokenizer.tokens()->stringifyList(0,true)); checkCondition.runSimplifiedChecks(&tokenizer, &settings, this); // Ensure that the test case is not bad. if (validate && str1 != str2) { warnUnsimplified(str1, str2); } } void assignAndCompare() { // & check("void foo(int x)\n" "{\n" " int y = x & 4;\n" " if (y == 3);\n" "}"); ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:4]: (style) Mismatching assignment and comparison, comparison 'y==3' is always false.\n", errout.str()); check("void foo(int x)\n" "{\n" " int y = x & 4;\n" " if (y != 3);\n" "}"); ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:4]: (style) Mismatching assignment and comparison, comparison 'y!=3' is always true.\n", errout.str()); // | check("void foo(int x) {\n" " int y = x | 0x14;\n" " if (y == 0x710);\n" "}"); ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:3]: (style) Mismatching assignment and comparison, comparison 'y==1808' is always false.\n", errout.str()); check("void foo(int x) {\n" " int y = x | 0x14;\n" " if (y == 0x71f);\n" "}"); ASSERT_EQUALS("", errout.str()); // various simple assignments check("void foo(int x) {\n" " int y = (x+1) | 1;\n" " if (y == 2);\n" "}"); ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:3]: (style) Mismatching assignment and comparison, comparison 'y==2' is always false.\n", errout.str()); check("void foo() {\n" " int y = 1 | x();\n" " if (y == 2);\n" "}"); ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:3]: (style) Mismatching assignment and comparison, comparison 'y==2' is always false.\n", errout.str()); // multiple conditions check("void foo(int x) {\n" " int y = x & 4;\n" " if ((y == 3) && (z == 1));\n" "}"); ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:3]: (style) Mismatching assignment and comparison, comparison 'y==3' is always false.\n", errout.str()); check("void foo(int x) {\n" " int y = x & 4;\n" " if ((x==123) || ((y == 3) && (z == 1)));\n" "}"); ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:3]: (style) Mismatching assignment and comparison, comparison 'y==3' is always false.\n", errout.str()); check("void f(int x) {\n" " int y = x & 7;\n" " if (setvalue(&y) && y != 8);\n" "}"); ASSERT_EQUALS("", errout.str()); // recursive checking into scopes check("void f(int x) {\n" " int y = x & 7;\n" " if (z) y=0;\n" " else { if (y==8); }\n" // always false "}"); ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:4]: (style) Mismatching assignment and comparison, comparison 'y==8' is always false.\n", errout.str()); // while check("void f(int x) {\n" " int y = x & 7;\n" " while (y==8);\n" // local variable => always false "}"); ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:3]: (style) Mismatching assignment and comparison, comparison 'y==8' is always false.\n", errout.str()); check("void f(int x) {\n" " extern int y; y = x & 7;\n" " while (y==8);\n" // non-local variable => no error "}"); ASSERT_EQUALS("", errout.str()); // calling function check("void f(int x) {\n" " int y = x & 7;\n" " do_something();\n" " if (y==8);\n" // local variable => always false "}"); ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:4]: (style) Mismatching assignment and comparison, comparison 'y==8' is always false.\n", errout.str()); check("void f(int x) {\n" " int y = x & 7;\n" " do_something(&y);\n" // passing variable => no error " if (y==8);\n" "}"); ASSERT_EQUALS("", errout.str()); check("void do_something(int);\n" "void f(int x) {\n" " int y = x & 7;\n" " do_something(y);\n" " if (y==8);\n" "}"); ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:5]: (style) Mismatching assignment and comparison, comparison 'y==8' is always false.\n", errout.str()); check("void f(int x) {\n" " extern int y; y = x & 7;\n" " do_something();\n" " if (y==8);\n" // non-local variable => no error "}"); ASSERT_EQUALS("", errout.str()); // #4434 : false positive: ?: check("void f(int x) {\n" " x = x & 1;\n" " x = x & 1 ? 1 : -1;\n" " if(x != -1) { }\n" "}"); ASSERT_EQUALS("", errout.str()); // #4735 check("void f() {\n" " int x = *(char*)&0x12345678;\n" " if (x==18) { }\n" "}"); ASSERT_EQUALS("", errout.str()); // bailout: no variable info check("void foo(int x) {\n" " y = 2 | x;\n" // y not declared => no error " if(y == 1) {}\n" "}"); ASSERT_EQUALS("", errout.str()); // bailout: negative number check("void foo(int x) {\n" " int y = -2 | x;\n" // negative number => no error " if (y==1) {}\n" "}"); ASSERT_EQUALS("", errout.str()); // bailout: pass variable to function check("void foo(int x) {\n" " int y = 2 | x;\n" " bar(&y);\n" // pass variable to function => no error " if (y==1) {}\n" "}"); ASSERT_EQUALS("", errout.str()); // no crash on unary operator& (#5643) check("SdrObject* ApplyGraphicToObject() {\n" " if (&rHitObject) {}\n" " else if (rHitObject.IsClosedObj() && !&rHitObject) { }\n" "}"); ASSERT_EQUALS("", errout.str()); // #5695: increment check("void f(int a0, int n) {\n" " int c = a0 & 3;\n" " for (int a = 0; a < n; a++) {\n" " c++;\n" " if (c == 4)\n" " c = 0;\n" " }\n" "}\n"); ASSERT_EQUALS("", errout.str()); } void mismatchingBitAnd() { check("void f(int a) {\n" " int b = a & 0xf0;\n" " b &= 1;\n" "}"); ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:3]: (style) Mismatching bitmasks. Result is always 0 (X = Y & 0xf0; Z = X & 0x1; => Z=0).\n", errout.str()); check("void f(int a) {\n" " int b = a & 0xf0;\n" " int c = b & 1;\n" "}"); ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:3]: (style) Mismatching bitmasks. Result is always 0 (X = Y & 0xf0; Z = X & 0x1; => Z=0).\n", errout.str()); check("void f(int a) {\n" " int b = a;" " switch (x) {\n" " case 1: b &= 1; break;\n" " case 2: b &= 2; break;\n" " };\n" "}"); ASSERT_EQUALS("", errout.str()); } void compare() { check("void foo(int x)\n" "{\n" " if ((x & 4) == 3);\n" "}"); ASSERT_EQUALS("[test.cpp:3]: (style) Expression '(X & 0x4) == 0x3' is always false.\n", errout.str()); check("void foo(int x)\n" "{\n" " if ((x | 4) == 3);\n" "}"); ASSERT_EQUALS("[test.cpp:3]: (style) Expression '(X | 0x4) == 0x3' is always false.\n", errout.str()); check("void foo(int x)\n" "{\n" " if ((x | 4) != 3);\n" "}"); ASSERT_EQUALS("[test.cpp:3]: (style) Expression '(X | 0x4) != 0x3' is always true.\n", errout.str()); check("void foo(int x)\n" "{\n" " if ((x & y & 4 & z ) == 3);\n" "}"); ASSERT_EQUALS("[test.cpp:3]: (style) Expression '(X & 0x4) == 0x3' is always false.\n", errout.str()); } void multicompare() { check("void foo(int x)\n" "{\n" " if (x & 7);\n" " else { if (x == 1); }\n" "}"); ASSERT_EQUALS("[test.cpp:4]: (style) Expression is always false because 'else if' condition matches previous condition at line 3.\n", errout.str()); check("void foo(int x)\n" "{\n" " if (x & 7);\n" " else { if (x & 1); }\n" "}"); ASSERT_EQUALS("[test.cpp:4]: (style) Expression is always false because 'else if' condition matches previous condition at line 3.\n", errout.str()); } void duplicateIf() { check("void f(int a, int &b) {\n" " if (a) { b = 1; }\n" " else { if (a) { b = 2; } }\n" "}"); ASSERT_EQUALS("[test.cpp:3]: (style) Expression is always false because 'else if' condition matches previous condition at line 2.\n", errout.str()); check("void f(int a, int &b) {\n" " if (a) { b = 1; }\n" " else { if (a) { b = 2; } }\n" "}"); ASSERT_EQUALS("[test.cpp:3]: (style) Expression is always false because 'else if' condition matches previous condition at line 2.\n", errout.str()); check("void f(int a, int &b) {\n" " if (a == 1) { b = 1; }\n" " else { if (a == 2) { b = 2; }\n" " else { if (a == 1) { b = 3; } } }\n" "}"); ASSERT_EQUALS("[test.cpp:4]: (style) Expression is always false because 'else if' condition matches previous condition at line 2.\n", errout.str()); check("void f(int a, int &b) {\n" " if (a == 1) { b = 1; }\n" " else { if (a == 2) { b = 2; }\n" " else { if (a == 2) { b = 3; } } }\n" "}"); ASSERT_EQUALS("[test.cpp:4]: (style) Expression is always false because 'else if' condition matches previous condition at line 3.\n", errout.str()); check("void f(int a, int &b) {\n" " if (a++) { b = 1; }\n" " else { if (a++) { b = 2; }\n" " else { if (a++) { b = 3; } } }\n" "}"); ASSERT_EQUALS("", errout.str()); check("void f(int a, int &b) {\n" " if (!strtok(NULL, \" \")) { b = 1; }\n" " else { if (!strtok(NULL, \" \")) { b = 2; } }\n" "}"); ASSERT_EQUALS("", errout.str()); check("void f(int a, int &b) {\n" " x = x / 2;\n" " if (x < 100) { b = 1; }\n" " else { x = x / 2; if (x < 100) { b = 2; } }\n" "}"); ASSERT_EQUALS("", errout.str()); check("void f(int i) {\n" " if(i == 0x02e2000000 || i == 0xa0c6000000)\n" " foo(i);\n" "}"); ASSERT_EQUALS("", errout.str()); // ticket 3689 ( avoid false positive ) check("int fitInt(long long int nValue){\n" " if( nValue < 0x7fffffffLL )\n" " {\n" " return 32;\n" " }\n" " if( nValue < 0x7fffffffffffLL )\n" " {\n" " return 48;\n" " }\n" " else {\n" " if( nValue < 0x7fffffffffffffffLL )\n" " {\n" " return 64;\n" " } else\n" " {\n" " return -1;\n" " }\n" " }\n" "}"); ASSERT_EQUALS("", errout.str()); check("void f(WIDGET *widget) {\n" " if (dynamic_cast(widget)){}\n" " else if (dynamic_cast(widget)){}\n" "}",false); ASSERT_EQUALS("", errout.str()); } void invalidMissingSemicolon() { // simply survive - a syntax error would be even better check("void f(int x) {\n" " x = 42\n" "}\n"); ASSERT_EQUALS("", errout.str()); } void incorrectLogicOperator1() { check("void f(int x) {\n" " if ((x != 1) || (x != 3))\n" " a++;\n" "}\n" ); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical disjunction always evaluates to true: x != 1 || x != 3.\n", errout.str()); check("void f(int x) {\n" " if (1 != x || 3 != x)\n" " a++;\n" "}\n" ); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical disjunction always evaluates to true: x != 1 || x != 3.\n", errout.str()); check("void f(int x) {\n" // ast.. " if (y == 1 && x == 1 && x == 7) { }\n" "}\n"); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical conjunction always evaluates to false: x == 1 && x == 7.\n", errout.str()); check("void f(int x, int y) {\n" " if (x != 1 || y != 1)\n" " a++;\n" "}\n" ); ASSERT_EQUALS("", errout.str()); check("void f(int x, int y) {\n" " if ((y == 1) && (x != 1) || (x != 3))\n" " a++;\n" "}\n" ); ASSERT_EQUALS("", errout.str()); check("void f(int x, int y) {\n" " if ((x != 1) || (x != 3) && (y == 1))\n" " a++;\n" "}\n" ); ASSERT_EQUALS("", errout.str()); check("void f(int x) {\n" " if ((x != 1) && (x != 3))\n" " a++;\n" "}\n" ); ASSERT_EQUALS("", errout.str()); check("void f(int x) {\n" " if ((x == 1) || (x == 3))\n" " a++;\n" "}\n" ); ASSERT_EQUALS("", errout.str()); check("void f(int x, int y) {\n" " if ((x != 1) || (y != 3))\n" " a++;\n" "}\n" ); ASSERT_EQUALS("", errout.str()); check("void f(int x, int y) {\n" " if ((x != hotdog) || (y != hotdog))\n" " a++;\n" "}\n" ); ASSERT_EQUALS("", errout.str()); check("void f(int x, int y) {\n" " if ((x != 5) || (y != 5))\n" " a++;\n" "}\n" ); ASSERT_EQUALS("", errout.str()); check("void f(int x) {\n" " if ((x != 5) || (x != 6))\n" " a++;\n" "}\n" ); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical disjunction always evaluates to true: x != 5 || x != 6.\n", errout.str()); check("void f(unsigned int a, unsigned int b, unsigned int c) {\n" " if((a != b) || (c != b) || (c != a))\n" " {\n" " return true;\n" " }\n" " return false;\n" "}\n" ); ASSERT_EQUALS("", errout.str()); } void incorrectLogicOperator2() { check("void f(float x) {\n" " if ((x == 1) && (x == 1.0))\n" " a++;\n" "}"); ASSERT_EQUALS("", errout.str()); check("void f(int x) {\n" " if ((x == 1) && (x == 0x00000001))\n" " a++;\n" "}"); ASSERT_EQUALS("", errout.str()); check("void f(int x) {\n" " if (x == 1 && x == 3)\n" " a++;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical conjunction always evaluates to false: x == 1 && x == 3.\n", errout.str()); check("void f(int x) {\n" " if (x == 1.0 && x == 3.0)\n" " a++;\n" "}"); //ASSERT_EQUALS("[test.cpp:2]: (warning) Logical conjunction always evaluates to false: x == 1.0 && x == 3.0.\n", errout.str()); ASSERT_EQUALS("", errout.str()); // float comparisons with == and != are not checked right now - such comparison is a bad idea check("void f(float x) {\n" " if (x == 1 && x == 1.0)\n" " a++;\n" "}"); ASSERT_EQUALS("", errout.str()); check("void bar(float f) {\n" // #5246 " if ((f > 0) && (f < 1)) {}\n" "}"); ASSERT_EQUALS("", errout.str()); check("void f(int x) {\n" " if (x < 1 && x > 1)\n" " a++;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical conjunction always evaluates to false: x < 1 && x > 1.\n", errout.str()); check("void f(int x) {\n" " if (x < 1.0 && x > 1.0)\n" " a++;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical conjunction always evaluates to false: x < 1.0 && x > 1.0.\n", errout.str()); check("void f(int x) {\n" " if (x < 1 && x > 1.0)\n" " a++;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical conjunction always evaluates to false: x < 1 && x > 1.0.\n", errout.str()); check("void f(int x) {\n" " if (x >= 1.0 && x <= 1.001)\n" " a++;\n" "}"); ASSERT_EQUALS("", errout.str()); check("void f(int x) {\n" " if (x < 1 && x > 3)\n" " a++;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical conjunction always evaluates to false: x < 1 && x > 3.\n", errout.str()); check("void f(float x) {\n" " if (x < 1.0 && x > 3.0)\n" " a++;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical conjunction always evaluates to false: x < 1.0 && x > 3.0.\n", errout.str()); check("void f(int x) {\n" " if (1 > x && 3 < x)\n" " a++;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical conjunction always evaluates to false: x < 1 && x > 3.\n", errout.str()); check("void f(int x) {\n" " if (x < 3 && x > 1)\n" " a++;\n" "}"); ASSERT_EQUALS("", errout.str()); check("void f(int x) {\n" " if (x > 3 || x < 10)\n" " a++;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical disjunction always evaluates to true: x > 3 || x < 10.\n", errout.str()); check("void f(int x) {\n" " if (x >= 3 || x <= 10)\n" " a++;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical disjunction always evaluates to true: x >= 3 || x <= 10.\n", errout.str()); check("void f(int x) {\n" " if (x >= 3 || x < 10)\n" " a++;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical disjunction always evaluates to true: x >= 3 || x < 10.\n", errout.str()); check("void f(int x) {\n" " if (x > 3 || x <= 10)\n" " a++;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical disjunction always evaluates to true: x > 3 || x <= 10.\n", errout.str()); check("void f(int x) {\n" " if (x > 3 || x < 3)\n" " a++;\n" "}"); ASSERT_EQUALS("", errout.str()); check("void f(int x) {\n" " if (x >= 3 || x <= 3)\n" " a++;\n" "}" ); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical disjunction always evaluates to true: x >= 3 || x <= 3.\n", errout.str()); check("void f(int x) {\n" " if (x >= 3 || x < 3)\n" " a++;\n" "}" ); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical disjunction always evaluates to true: x >= 3 || x < 3.\n", errout.str()); check("void f(int x) {\n" " if (x > 3 || x <= 3)\n" " a++;\n" "}" ); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical disjunction always evaluates to true: x > 3 || x <= 3.\n", errout.str()); check("void f(int x) {\n" " if((x==3) && (x!=4))\n" " a++;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (style) Redundant condition: If x == 3, the comparison x != 4 is always true.\n", errout.str()); check("void f(int x) {\n" " if ((x!=4) && (x==3))\n" " a++;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (style) Redundant condition: If x == 3, the comparison x != 4 is always true.\n", errout.str()); check("void f(int x) {\n" " if ((x==3) || (x!=4))\n" " a++;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (style) Redundant condition: If x == 3, the comparison x != 4 is always true.\n", errout.str()); check("void f(int x) {\n" " if ((x!=4) || (x==3))\n" " a++;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (style) Redundant condition: If x == 3, the comparison x != 4 is always true.\n", errout.str()); check("void f(int x) {\n" " if ((x==3) && (x!=3))\n" " a++;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical conjunction always evaluates to false: x == 3 && x != 3.\n", errout.str()); check("void f(int x) {\n" " if ((x==6) || (x!=6))\n" " a++;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical disjunction always evaluates to true: x == 6 || x != 6.\n", errout.str()); check("void f(int x) {\n" " if (x > 10 || x < 3)\n" " a++;\n" "}"); ASSERT_EQUALS("", errout.str()); check("void f(int x) {\n" " if (x > 5 && x == 1)\n" " a++;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical conjunction always evaluates to false: x > 5 && x == 1.\n", errout.str()); check("void f(int x) {\n" " if (x > 5 && x == 6)\n" " a++;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (style) Redundant condition: If x == 6, the comparison x > 5 is always true.\n", errout.str()); // #3419 check("void f() {\n" " if ( &q != &a && &q != &b ) { }\n" "}"); ASSERT_EQUALS("", errout.str()); // #3676 check("void f(int m_x2, int w, int x) {\n" " if (x + w - 1 > m_x2 || m_x2 < 0 )\n" " m_x2 = x + w - 1;\n" "}"); ASSERT_EQUALS("", errout.str()); check("void f(float x) {\n" // x+1 => x " if (x <= 1.0e20 && x >= -1.0e20) {}\n" "}"); ASSERT_EQUALS("", errout.str()); check("void f(float x) {\n" // x+1 => x " if (x >= 1.0e20 && x <= 1.0e21) {}\n" "}"); ASSERT_EQUALS("", errout.str()); check("void f(float x) {\n" // x+1 => x " if (x <= -1.0e20 && x >= -1.0e21) {}\n" "}"); ASSERT_EQUALS("", errout.str()); } void incorrectLogicOperator3() { check("void f(int x, bool& b) {\n" " b = x > 5 && x == 1;\n" " c = x < 1 && x == 3;\n" " d = x >= 5 && x == 1;\n" " e = x <= 1 && x == 3;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical conjunction always evaluates to false: x > 5 && x == 1.\n" "[test.cpp:3]: (warning) Logical conjunction always evaluates to false: x < 1 && x == 3.\n" "[test.cpp:4]: (warning) Logical conjunction always evaluates to false: x >= 5 && x == 1.\n" "[test.cpp:5]: (warning) Logical conjunction always evaluates to false: x <= 1 && x == 3.\n", errout.str()); } void incorrectLogicOperator4() { check("void f(int x) {\n" " if (x && x != $0) {}\n" "}"); ASSERT_EQUALS("", errout.str()); } void incorrectLogicOperator5() { // complex expressions check("void f(int x) {\n" " if (x+3 > 2 || x+3 < 10) {}\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical disjunction always evaluates to true: EXPR > 2 || EXPR < 10.\n", errout.str()); } void incorrectLogicOperator6() { // char literals check("void f(char x) {\n" " if (x == '1' || x == '2') {}\n" "}"); ASSERT_EQUALS("", errout.str()); check("void f(char x) {\n" " if (x == '1' && x == '2') {}\n" "}"); TODO_ASSERT_EQUALS("error", "", errout.str()); } void incorrectLogicOperator7() { // opposite expressions check("void f(int i) {\n" " if (i || !i) {}\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical disjunction always evaluates to true: i||!i.\n", errout.str()); } void secondAlwaysTrueFalseWhenFirstTrueError() { check("void f(int x) {\n" " if (x > 5 && x != 1)\n" " a++;\n" "}\n" ); ASSERT_EQUALS("[test.cpp:2]: (style) Redundant condition: If x > 5, the comparison x != 1 is always true.\n", errout.str()); check("void f(int x) {\n" " if (x > 5 && x != 6)\n" " a++;\n" "}\n" ); ASSERT_EQUALS("", errout.str()); check("void f(int x) {\n" " if ((x > 5) && (x != 1))\n" " a++;\n" "}\n" ); ASSERT_EQUALS("[test.cpp:2]: (style) Redundant condition: If x > 5, the comparison x != 1 is always true.\n", errout.str()); check("void f(int x) {\n" " if ((x > 5) && (x != 6))\n" " a++;\n" "}\n" ); ASSERT_EQUALS("", errout.str()); check("void f(int x, bool& b) {\n" " b = x > 3 || x == 4;\n" " c = x < 5 || x == 4;\n" " d = x >= 3 || x == 4;\n" " e = x <= 5 || x == 4;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (style) Redundant condition: If x == 4, the comparison x > 3 is always true.\n" "[test.cpp:3]: (style) Redundant condition: If x == 4, the comparison x < 5 is always true.\n" "[test.cpp:4]: (style) Redundant condition: If x == 4, the comparison x >= 3 is always true.\n" "[test.cpp:5]: (style) Redundant condition: If x == 4, the comparison x <= 5 is always true.\n", errout.str()); check("void f(int x, bool& b) {\n" " b = x > 5 || x != 1;\n" " c = x < 1 || x != 3;\n" " d = x >= 5 || x != 1;\n" " e = x <= 1 || x != 3;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (style) Redundant condition: If x > 5, the comparison x != 1 is always true.\n" "[test.cpp:3]: (style) Redundant condition: If x < 1, the comparison x != 3 is always true.\n" "[test.cpp:4]: (style) Redundant condition: If x >= 5, the comparison x != 1 is always true.\n" "[test.cpp:5]: (style) Redundant condition: If x <= 1, the comparison x != 3 is always true.\n", errout.str()); check("void f(int x, bool& b) {\n" " b = x > 6 && x > 5;\n" " c = x > 5 || x > 6;\n" " d = x < 6 && x < 5;\n" " e = x < 5 || x < 6;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (style) Redundant condition: If x > 6, the comparison x > 5 is always true.\n" "[test.cpp:3]: (style) Redundant condition: If x > 6, the comparison x > 5 is always true.\n" "[test.cpp:4]: (style) Redundant condition: If x < 5, the comparison x < 6 is always true.\n" "[test.cpp:5]: (style) Redundant condition: If x < 5, the comparison x < 6 is always true.\n", errout.str()); } void incorrectLogicOp_condSwapping() { check("void f(int x) {\n" " if (x < 1 && x > 3)\n" " a++;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical conjunction always evaluates to false: x < 1 && x > 3.\n", errout.str()); check("void f(int x) {\n" " if (1 > x && x > 3)\n" " a++;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical conjunction always evaluates to false: x < 1 && x > 3.\n", errout.str()); check("void f(int x) {\n" " if (x < 1 && 3 < x)\n" " a++;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical conjunction always evaluates to false: x < 1 && x > 3.\n", errout.str()); check("void f(int x) {\n" " if (1 > x && 3 < x)\n" " a++;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical conjunction always evaluates to false: x < 1 && x > 3.\n", errout.str()); check("void f(int x) {\n" " if (x > 3 && x < 1)\n" " a++;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical conjunction always evaluates to false: x > 3 && x < 1.\n", errout.str()); check("void f(int x) {\n" " if (3 < x && x < 1)\n" " a++;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical conjunction always evaluates to false: x > 3 && x < 1.\n", errout.str()); check("void f(int x) {\n" " if (x > 3 && 1 > x)\n" " a++;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical conjunction always evaluates to false: x > 3 && x < 1.\n", errout.str()); check("void f(int x) {\n" " if (3 < x && 1 > x)\n" " a++;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (warning) Logical conjunction always evaluates to false: x > 3 && x < 1.\n", errout.str()); } void modulo() { check("bool f(bool& b1, bool& b2, bool& b3) {\n" " b1 = a % 5 == 4;\n" " b2 = a % c == 100000;\n" " b3 = a % 5 == c;\n" " return a % 5 == 5-p;\n" "}"); ASSERT_EQUALS("", errout.str()); check("bool f(bool& b1, bool& b2, bool& b3, bool& b4, bool& b5) {\n" " b1 = a % 5 < 5;\n" " b2 = a % 5 <= 5;\n" " b3 = a % 5 == 5;\n" " b4 = a % 5 != 5;\n" " b5 = a % 5 >= 5;\n" " return a % 5 > 5;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (warning) Comparison of modulo result is predetermined, because it is always less than 5.\n" "[test.cpp:3]: (warning) Comparison of modulo result is predetermined, because it is always less than 5.\n" "[test.cpp:4]: (warning) Comparison of modulo result is predetermined, because it is always less than 5.\n" "[test.cpp:5]: (warning) Comparison of modulo result is predetermined, because it is always less than 5.\n" "[test.cpp:6]: (warning) Comparison of modulo result is predetermined, because it is always less than 5.\n" "[test.cpp:7]: (warning) Comparison of modulo result is predetermined, because it is always less than 5.\n", errout.str()); check("void f(bool& b1, bool& b2) {\n" " b1 = bar() % 5 < 889;\n" " if(x[593] % 5 <= 5)\n" " b2 = x.a % 5 == 5;\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (warning) Comparison of modulo result is predetermined, because it is always less than 5.\n" "[test.cpp:3]: (warning) Comparison of modulo result is predetermined, because it is always less than 5.\n" "[test.cpp:4]: (warning) Comparison of modulo result is predetermined, because it is always less than 5.\n", errout.str()); check("void f() {\n" " if (a % 2 + b % 2 == 2)\n" " foo();\n" "}"); ASSERT_EQUALS("", errout.str()); } void oppositeInnerCondition() { check("void foo(int a, int b) {\n" " if(a==b)\n" " if(a!=b)\n" " cout << a;\n" "}"); ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:3]: (warning) Opposite conditions in nested 'if' blocks lead to a dead code block.\n", errout.str()); check("void foo(int a, int b) {\n" " if(a==b)\n" " if(b!=a)\n" " cout << a;\n" "}"); ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:3]: (warning) Opposite conditions in nested 'if' blocks lead to a dead code block.\n", errout.str()); check("void foo(int a) {\n" " if(a >= 50) {\n" " if(a < 50)\n" " cout << a;\n" " else\n" " cout << 100;\n" " }\n" "}"); ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:3]: (warning) Opposite conditions in nested 'if' blocks lead to a dead code block.\n", errout.str()); // #4186 check("void foo(int a) {\n" " if(a >= 50) {\n" " if(a > 50)\n" " cout << a;\n" " else\n" " cout << 100;\n" " }\n" "}"); ASSERT_EQUALS("", errout.str()); // 4170 check("class foo {\n" " void bar() {\n" " if (tok == '(') {\n" " next();\n" " if (tok == ',') {\n" " next();\n" " if (tok != ',') {\n" " op->reg2 = asm_parse_reg();\n" " }\n" " skip(',');\n" " }\n" " }\n" " }\n" " void next();\n" " const char *tok;\n" "};"); ASSERT_EQUALS("", errout.str()); check("void foo(int i)\n" "{\n" " if(i > 5) {\n" " i = bar();\n" " if(i < 5) {\n" " cout << a;\n" " }\n" " }\n" "}"); ASSERT_EQUALS("", errout.str()); check("void foo(int& i) {\n" " i=6;\n" "}\n" "void bar(int i) {\n" " if(i>5) {\n" " foo(i);\n" " if(i<5) {\n" " }\n" " }\n" "}"); ASSERT_EQUALS("", errout.str()); check("void foo(int& i);\n" "void bar() {\n" " int i; i = func();\n" " if(i>5) {\n" " foo(i);\n" " if(i<5) {\n" " }\n" " }\n" "}"); ASSERT_EQUALS("", errout.str()); check("void foo(int i);\n" "void bar(int i) {\n" " if(i>5) {\n" " foo(i);\n" " if(i<5) {\n" " }\n" " }\n" "}"); ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:5]: (warning) Opposite conditions in nested 'if' blocks lead to a dead code block.\n", errout.str()); check("void foo(int i);\n" "void bar() {\n" " int i; i = func();\n" " if(i>5) {\n" " foo(i);\n" " if(i<5) {\n" " }\n" " }\n" "}"); ASSERT_EQUALS("[test.cpp:4] -> [test.cpp:6]: (warning) Opposite conditions in nested 'if' blocks lead to a dead code block.\n", errout.str()); // see linux revision 1f80c0cc check("int generic_write_sync(int,int,int);\n" "\n" "void cifs_writev(int i) {\n" " int rc = __generic_file_aio_write();\n" " if (rc > 0){\n" " err = generic_write_sync(file, iocb->ki_pos - rc, rc);\n" " if(rc < 0) {\n" // <- condition is always false " err = rc;\n" " }\n" " }\n" "}"); ASSERT_EQUALS("[test.cpp:5] -> [test.cpp:7]: (warning) Opposite conditions in nested 'if' blocks lead to a dead code block.\n", errout.str()); check("void f(struct ABC *abc) {\n" " struct AB *ab = abc->ab;\n" " if (ab->a == 123){\n" " do_something(abc);\n" // might change ab->a " if (ab->a != 123) {\n" " err = rc;\n" " }\n" " }\n" "}"); ASSERT_EQUALS("", errout.str()); // #5731 - fp when undeclared variable is used check("void f() {\n" " if (x == -1){\n" " x = do_something();\n" " if (x != -1) {}\n" " }\n" "}"); ASSERT_EQUALS("", errout.str()); // #5750 - another fp when undeclared variable is used check("void f() {\n" " if (r < w){\n" " r += 3;\n" " if (r > w) {}\n" " }\n" "}"); ASSERT_EQUALS("", errout.str()); // #5874 - array check("void testOppositeConditions2() {\n" " int array[2] = { 0, 0 };\n" " if (array[0] < 2) {\n" " array[0] += 5;\n" " if (array[0] > 2) {}\n" " }\n" "}"); ASSERT_EQUALS("", errout.str()); } // clarify conditions with = and comparison void clarifyCondition1() { check("void f() {\n" " if (x = b() < 0) {}\n" // don't simplify and verify this code "}", false); ASSERT_EQUALS("[test.cpp:2]: (style) Suspicious condition (assignment + comparison); Clarify expression with parentheses.\n", errout.str()); check("void f(int i) {\n" " for (i = 0; i < 10; i++) {}\n" "}"); ASSERT_EQUALS("", errout.str()); check("void f() {\n" " x = a(); if (x) {}\n" "}"); ASSERT_EQUALS("", errout.str()); } // clarify conditions with bitwise operator and comparison void clarifyCondition2() { check("void f() {\n" " if (x & 3 == 2) {}\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (style) Suspicious condition (bitwise operator + comparison); Clarify expression with parentheses.\n", errout.str()); check("void f() {\n" " if (a & fred1.x == fred2.y) {}\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (style) Suspicious condition (bitwise operator + comparison); Clarify expression with parentheses.\n", errout.str()); } // clarify condition that uses ! operator and then bitwise operator void clarifyCondition3() { check("void f(int w) {\n" " if(!w & 0x8000) {}\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (style) Boolean result is used in bitwise operation. Clarify expression with parentheses.\n", errout.str()); check("void f() {\n" " if (x == foo() & 2) {}\n" "}"); ASSERT_EQUALS("[test.cpp:2]: (style) Boolean result is used in bitwise operation. Clarify expression with parentheses.\n", errout.str()); check("void f(std::list &ints) { }"); ASSERT_EQUALS("", errout.str()); check("void f() { A a; }"); ASSERT_EQUALS("", errout.str()); check("void f() { a(x there are never templates ASSERT_EQUALS("[test.c:1]: (style) Boolean result is used in bitwise operation. Clarify expression with parentheses.\n", errout.str()); check("class A;", true, "test.cpp"); ASSERT_EQUALS("", errout.str()); check("void f() {\n" " if (result != (char *)&inline_result) { }\n" // don't simplify and verify cast "}", false); ASSERT_EQUALS("", errout.str()); } void clarifyCondition4() { // ticket #3110 check("typedef double SomeType;\n" "typedef std::pair PairType;\n" "struct S\n" "{\n" " bool operator()\n" " ( PairType const & left\n" " , PairType const & right) const\n" " {\n" " return left.first < right.first;\n" " }\n" "}"); ASSERT_EQUALS("", errout.str()); } void clarifyCondition5() { // ticket #3609 (using | in template instantiation) check("CWinTraits::GetWndStyle(0);"); ASSERT_EQUALS("", errout.str()); } void clarifyCondition6() { check("template\n" "SharedPtr& operator=( SharedPtr const & r ) {\n" " px = r.px;\n" " return *this;\n" "}"); ASSERT_EQUALS("", errout.str()); } }; REGISTER_TEST(TestCondition)