testcondition.cpp

/*
 * Cppcheck - A tool for static C/C++ code analysis
 * Copyright (C) 2007-2026 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 <http://www.gnu.org/licenses/>.
 */

#include "checkcondition.h"
#include "errortypes.h"
#include "fixture.h"
#include "helpers.h"
#include "platform.h"
#include "settings.h"

#include <cstddef>
#include <string>

class TestCondition : public TestFixture {
public:
    TestCondition() : TestFixture("TestCondition") {}

private:
    const Settings settings0 = settingsBuilder().library("qt.cfg").library("std.cfg").severity(Severity::style).severity(Severity::warning).build();
    /*const*/ Settings settings1 = settingsBuilder().severity(Severity::style).severity(Severity::warning).build();
    const Settings settings2 = settingsBuilder(settings0).severity(Severity::performance).certainty(Certainty::inconclusive).build();

    void run() override {
        const char cfg[] = "<?xml version=\"1.0\"?>\n"
                           "<def>\n"
                           "  <function name=\"bar\"> <pure/> </function>\n"
                           "</def>";
        settings1 = settingsBuilder(settings1).libraryxml(cfg).build();

        mNewTemplate = true;
        TEST_CASE(assignAndCompare);   // assignment and comparison don't match
        TEST_CASE(mismatchingBitAnd);  // overlapping bitmasks
        TEST_CASE(comparison);         // CheckCondition::comparison test cases
        TEST_CASE(multicompare);       // mismatching comparisons
        TEST_CASE(overlappingElseIfCondition);  // overlapping conditions in if and else-if
        TEST_CASE(oppositeElseIfCondition); // opposite conditions in if and else-if

        TEST_CASE(checkBadBitmaskCheck);

        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(incorrectLogicOperator8); // !
        TEST_CASE(incorrectLogicOperator9);
        TEST_CASE(incorrectLogicOperator10); // enum
        TEST_CASE(incorrectLogicOperator11);
        TEST_CASE(incorrectLogicOperator12);
        TEST_CASE(incorrectLogicOperator13);
        TEST_CASE(incorrectLogicOperator14);
        TEST_CASE(incorrectLogicOperator15);
        TEST_CASE(incorrectLogicOperator16); // #10070
        TEST_CASE(incorrectLogicOperator17);
        TEST_CASE(secondAlwaysTrueFalseWhenFirstTrueError);
        TEST_CASE(incorrectLogicOp_condSwapping);
        TEST_CASE(testBug5895);
        TEST_CASE(testBug5309);

        TEST_CASE(modulo);

        TEST_CASE(oppositeInnerCondition);
        TEST_CASE(oppositeInnerConditionPointers);
        TEST_CASE(oppositeInnerConditionClass);
        TEST_CASE(oppositeInnerConditionUndeclaredVariable);
        TEST_CASE(oppositeInnerConditionAlias);
        TEST_CASE(oppositeInnerCondition2);
        TEST_CASE(oppositeInnerCondition3);
        TEST_CASE(oppositeInnerConditionAnd);
        TEST_CASE(oppositeInnerConditionOr);
        TEST_CASE(oppositeInnerConditionEmpty);
        TEST_CASE(oppositeInnerConditionFollowVar);
        TEST_CASE(oppositeInnerConditionLambda);

        TEST_CASE(identicalInnerCondition);

        TEST_CASE(identicalConditionAfterEarlyExit);
        TEST_CASE(innerConditionModified);

        TEST_CASE(overlappingInnerCondition);

        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<WS_CHILD|WS_VISIBLE>..
        TEST_CASE(clarifyCondition6);     // #3818
        TEST_CASE(clarifyCondition7);
        TEST_CASE(clarifyCondition8);

        TEST_CASE(alwaysTrue);
        TEST_CASE(alwaysTrueSymbolic);
        TEST_CASE(alwaysTrueInfer);
        TEST_CASE(alwaysTrueContainer);
        TEST_CASE(alwaysTrueLoop);
        TEST_CASE(alwaysTrueTryCatch);
        TEST_CASE(alwaysTrueSideEffect);
        TEST_CASE(alwaysTruePremiumMisra);
        TEST_CASE(multiConditionAlwaysTrue);
        TEST_CASE(duplicateCondition);

        TEST_CASE(checkInvalidTestForOverflow);
        TEST_CASE(checkConditionIsAlwaysTrueOrFalseInsideIfWhile);
        TEST_CASE(alwaysTrueFalseInLogicalOperators);
        TEST_CASE(pointerAdditionResultNotNull);
        TEST_CASE(duplicateConditionalAssign);

        TEST_CASE(checkAssignmentInCondition);
        TEST_CASE(compareOutOfTypeRange);
        TEST_CASE(knownConditionCast); // #9976
        TEST_CASE(knownConditionIncrementLoop); // #9808
        TEST_CASE(knownConditionAfterBailout); // #12526
        TEST_CASE(knownConditionIncDecOperator);
        TEST_CASE(knownConditionFloating);
    }

    struct CheckOptions
    {
        bool cpp = true;
    };

#define check(...) check_(__FILE__, __LINE__, __VA_ARGS__)
    template<size_t size>
    void check_(const char* file, int line, const char (&code)[size], const CheckOptions& options = make_default_obj()) {
        check_(file, line, code, settings0, options.cpp);
    }

    template<size_t size>
    void check_(const char* file, int line, const char (&code)[size], const Settings& settings, bool cpp = true) {
        SimpleTokenizer2 tokenizer(settings, *this, code, cpp ? "test.cpp" : "test.c");

        // Tokenizer..
        ASSERT_LOC(tokenizer.simplifyTokens1(""), file, line);

        // Run checks..
        runChecks<CheckCondition>(tokenizer, this);
    }

#define checkP(...) checkP_(__FILE__, __LINE__, __VA_ARGS__)
    template<size_t size>
    void checkP_(const char* file, int line, const char (&code)[size])
    {
        SimpleTokenizer2 tokenizer(settings2, *this, code, "test.cpp");

        // Tokenizer..
        ASSERT_LOC(tokenizer.simplifyTokens1(""), file, line);

        // Run checks..
        runChecks<CheckCondition>(tokenizer, this);
    }

    void assignAndCompare() {
        // &
        check("void foo(int x)\n"
              "{\n"
              "    int y = x & 4;\n"
              "    if (y == 3);\n"
              "}");
        ASSERT_EQUALS("[test.cpp:3:11] -> [test.cpp:4:8]: (style) Mismatching assignment and comparison, comparison 'y==3' is always false. [assignIfError]\n", errout_str());

        check("void foo(int x)\n"
              "{\n"
              "    int y = x & 4;\n"
              "    if (y != 3);\n"
              "}");
        ASSERT_EQUALS("[test.cpp:3:11] -> [test.cpp:4:8]: (style) Mismatching assignment and comparison, comparison 'y!=3' is always true. [assignIfError]\n", errout_str());

        // |
        check("void foo(int x) {\n"
              "    int y = x | 0x14;\n"
              "    if (y == 0x710);\n"
              "}");
        ASSERT_EQUALS("[test.cpp:2:11] -> [test.cpp:3:8]: (style) Mismatching assignment and comparison, comparison 'y==0x710' is always false. [assignIfError]\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:2:11] -> [test.cpp:3:8]: (style) Mismatching assignment and comparison, comparison 'y==2' is always false. [assignIfError]\n", errout_str());

        check("void foo() {\n"
              "    int y = 1 | x();\n"
              "    if (y == 2);\n"
              "}");
        ASSERT_EQUALS("[test.cpp:2:11] -> [test.cpp:3:8]: (style) Mismatching assignment and comparison, comparison 'y==2' is always false. [assignIfError]\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:2:11] -> [test.cpp:3:9]: (style) Mismatching assignment and comparison, comparison 'y==3' is always false. [assignIfError]\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:2:11] -> [test.cpp:3:22]: (style) Mismatching assignment and comparison, comparison 'y==3' is always false. [assignIfError]\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:2:11] -> [test.cpp:4:15]: (style) Mismatching assignment and comparison, comparison 'y==8' is always false. [assignIfError]\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:2:11] -> [test.cpp:3:11]: (style) Mismatching assignment and comparison, comparison 'y==8' is always false. [assignIfError]\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());

        check("void f(int x) {\n"
              "    int a = 100;\n"
              "    while (x) {\n"
              "        int y = 16 | a;\n"
              "        while (y != 0) y--;\n"
              "    }\n"
              "}");
        ASSERT_EQUALS("", errout_str());

        check("void g(int x);\n"
              "void f(int x) {\n"
              "    int a = 100;\n"
              "    while (x) {\n"
              "        int y = 16 | a;\n"
              "        while (y != 0) g(y);\n"
              "    }\n"
              "}");
        ASSERT_EQUALS(
            "[test.cpp:5:15] -> [test.cpp:6:15]: (style) Mismatching assignment and comparison, comparison 'y!=0' is always true. [assignIfError]\n",
            errout_str());

        check("void g(int &x);\n"
              "void f(int x) {\n"
              "    int a = 100;\n"
              "    while (x) {\n"
              "        int y = 16 | a;\n"
              "        while (y != 0) g(y);\n"
              "    }\n"
              "}");
        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:2:11] -> [test.cpp:4:8]: (style) Mismatching assignment and comparison, comparison 'y==8' is always false. [assignIfError]\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:3:11] -> [test.cpp:5:8]: (style) Mismatching assignment and comparison, comparison 'y==8' is always false. [assignIfError]\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)
        // #11610
        check("SdrObject* ApplyGraphicToObject() {\n"
              "    if (&rHitObject) {}\n"
              "    else if (rHitObject.IsClosedObj() && !&rHitObject) { }\n"
              "}");
        ASSERT_EQUALS("[test.cpp:2:9]: (style) Condition '&rHitObject' is always true [knownConditionTrueFalse]\n"
                      "[test.cpp:3:42]: (style) Condition '!&rHitObject' is always false [knownConditionTrueFalse]\n",
                      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"
              "}");
        ASSERT_EQUALS("", errout_str());

        check("void f(int a) {\n" // #6662
              "  int x = a & 1;\n"
              "  while (x <= 4) {\n"
              "    if (x != 5) {}\n"
              "  }\n"
              "}");
        ASSERT_EQUALS("[test.cpp:2:9] -> [test.cpp:4:8]: (style) Mismatching assignment and comparison, comparison 'x!=5' is always true. [assignIfError]\n", errout_str());

        check("void f(int a) {\n" // #6662
              "  int x = a & 1;\n"
              "  while ((x += 4) < 10) {\n"
              "    if (x != 5) {}\n"
              "  }\n"
              "}");
        ASSERT_EQUALS("", errout_str());

        check("void f() {\n"
              "    int x = 100;\n"
              "    while (x) {\n"
              "        g(x);\n"
              "    }\n"
              "}");
        ASSERT_EQUALS("", errout_str());

        check("void g(int x);\n"
              "void f() {\n"
              "    int x = 100;\n"
              "    while (x) {\n"
              "        g(x);\n"
              "    }\n"
              "}");
        ASSERT_EQUALS("[test.cpp:4:12]: (style) Condition 'x' is always true [knownConditionTrueFalse]\n", errout_str());

        check("void g(int & x);\n"
              "void f() {\n"
              "    int x = 100;\n"
              "    while (x) {\n"
              "        g(x);\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:2:11] -> [test.cpp:3:5]: (style) Mismatching bitmasks. Result is always 0 (X = Y & 0xf0; Z = X & 0x1; => Z=0). [mismatchingBitAnd]\n", errout_str());

        check("void f(int a) {\n"
              "    int b = a & 0xf0;\n"
              "    int c = b & 1;\n"
              "}");
        ASSERT_EQUALS("[test.cpp:2:11] -> [test.cpp:3:9]: (style) Mismatching bitmasks. Result is always 0 (X = Y & 0xf0; Z = X & 0x1; => Z=0). [mismatchingBitAnd]\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 comparison() {
        // CheckCondition::comparison test cases
        // '=='
        check("void f(int a) {\n assert( (a & 0x07) == 8U );\n}");
        ASSERT_EQUALS("[test.cpp:2:13]: (style) Expression '(X & 0x7) == 0x8' is always false. [comparisonError]\n",errout_str());
        check("void f(int a) {\n assert( (a & b & 4 & c ) == 3 );\n}");
        ASSERT_EQUALS("[test.cpp:2:21]: (style) Expression '(X & 0x4) == 0x3' is always false. [comparisonError]\n", errout_str());
        check("void f(int a) {\n assert( (a | 0x07) == 8U );\n}");
        ASSERT_EQUALS("[test.cpp:2:13]: (style) Expression '(X | 0x7) == 0x8' is always false. [comparisonError]\n",errout_str());
        check("void f(int a) {\n assert( (a & 0x07) == 7U );\n}");
        ASSERT_EQUALS("", errout_str());
        check("void f(int a) {\n assert( (a | 0x01) == -15 );\n}");
        ASSERT_EQUALS("", errout_str());
        // '!='
        check("void f(int a) {\n assert( (a & 0x07) != 8U );\n}");
        ASSERT_EQUALS("[test.cpp:2:13]: (style) Expression '(X & 0x7) != 0x8' is always true. [comparisonError]\n",errout_str());
        check("void f(int a) {\n assert( (a | 0x07) != 8U );\n}");
        ASSERT_EQUALS("[test.cpp:2:13]: (style) Expression '(X | 0x7) != 0x8' is always true. [comparisonError]\n",errout_str());
        check("void f(int a) {\n assert( (a & 0x07) != 7U );\n}");
        ASSERT_EQUALS("", errout_str());
        check("void f(int a) {\n assert( (a | 0x07) != 7U );\n}");
        ASSERT_EQUALS("", errout_str());
        // '>='
        check("void f(int a) {\n assert( (a & 0x07) >= 8U );\n}");
        ASSERT_EQUALS("[test.cpp:2:13]: (style) Expression '(X & 0x7) >= 0x8' is always false. [comparisonError]\n",errout_str());
        check("void f(unsigned int a) {\n assert( (a | 0x7) >= 7U );\n}");
        ASSERT_EQUALS("[test.cpp:2:13]: (style) Expression '(X | 0x7) >= 0x7' is always true. [comparisonError]\n",errout_str());
        check("void f(int a) {\n assert( (a & 0x07) >= 7U );\n}");
        ASSERT_EQUALS("",errout_str());
        check("void f(int a) {\n assert( (a | 0x07) >= 8U );\n}");
        ASSERT_EQUALS("",errout_str()); //correct for negative 'a'
        // '>'
        check("void f(int a) {\n assert( (a & 0x07) > 7U );\n}");
        ASSERT_EQUALS("[test.cpp:2:13]: (style) Expression '(X & 0x7) > 0x7' is always false. [comparisonError]\n",errout_str());
        check("void f(unsigned int a) {\n assert( (a | 0x7) > 6U );\n}");
        ASSERT_EQUALS("[test.cpp:2:13]: (style) Expression '(X | 0x7) > 0x6' is always true. [comparisonError]\n",errout_str());
        check("void f(int a) {\n assert( (a & 0x07) > 6U );\n}");
        ASSERT_EQUALS("",errout_str());
        check("void f(int a) {\n assert( (a | 0x07) > 7U );\n}");
        ASSERT_EQUALS("",errout_str()); //correct for negative 'a'
        // '<='
        check("void f(int a) {\n assert( (a & 0x07) <= 7U );\n}");
        ASSERT_EQUALS("[test.cpp:2:13]: (style) Expression '(X & 0x7) <= 0x7' is always true. [comparisonError]\n",errout_str());
        check("void f(unsigned int a) {\n assert( (a | 0x08) <= 7U );\n}");
        ASSERT_EQUALS("[test.cpp:2:13]: (style) Expression '(X | 0x8) <= 0x7' is always false. [comparisonError]\n",errout_str());
        check("void f(int a) {\n assert( (a & 0x07) <= 6U );\n}");
        ASSERT_EQUALS("",errout_str());
        check("void f(int a) {\n assert( (a | 0x08) <= 7U );\n}");
        ASSERT_EQUALS("",errout_str()); //correct for negative 'a'
        // '<'
        check("void f(int a) {\n assert( (a & 0x07) < 8U );\n}");
        ASSERT_EQUALS("[test.cpp:2:13]: (style) Expression '(X & 0x7) < 0x8' is always true. [comparisonError]\n",errout_str());
        check("void f(unsigned int a) {\n assert( (a | 0x07) < 7U );\n}");
        ASSERT_EQUALS("[test.cpp:2:13]: (style) Expression '(X | 0x7) < 0x7' is always false. [comparisonError]\n",errout_str());
        check("void f(int a) {\n assert( (a & 0x07) < 3U );\n}");
        ASSERT_EQUALS("",errout_str());
        check("void f(int a) {\n assert( (a | 0x07) < 7U );\n}");
        ASSERT_EQUALS("",errout_str()); //correct for negative 'a'

        check("void f(int i) {\n" // #11998
              "    if ((i & 0x100) == 0x200) {}\n"
              "    if (0x200 == (i & 0x100)) {}\n"
              "}\n");
        ASSERT_EQUALS("[test.cpp:2:21] -> [test.cpp:3:15]: (style) The if condition is the same as the previous if condition [duplicateCondition]\n"
                      "[test.cpp:2:12]: (style) Expression '(X & 0x100) == 0x200' is always false. [comparisonError]\n"
                      "[test.cpp:3:21]: (style) Expression '(X & 0x100) == 0x200' is always false. [comparisonError]\n",
                      errout_str());

        checkP("#define MACRO1 (0x0010)\n" // #13222
               "#define MACRO2 (0x0020)\n"
               "#define MACRO_ALL (MACRO1 | MACRO2)\n"
               "void f() {\n"
               "    if (MACRO_ALL == 0) {}\n"
               "}\n");
        ASSERT_EQUALS("", errout_str());

        checkP("void f(int i, int j) {\n" // #13360
               "    int X = 0x10;\n"
               "    if ((i & 0xff00) == X) {}\n"
               "    if (X == (j & 0xff00)) {}\n"
               "}\n");
        ASSERT_EQUALS("[test.cpp:3:12]: (style) Expression '(X & 0xff00) == 0x10' is always false. [comparisonError]\n"
                      "[test.cpp:4:17]: (style) Expression '(X & 0xff00) == 0x10' is always false. [comparisonError]\n",
                      errout_str());
    }

#define checkPureFunction(...) checkPureFunction_(__FILE__, __LINE__, __VA_ARGS__)
    template<size_t size>
    void checkPureFunction_(const char* file, int line, const char (&code)[size]) {
        // Tokenize..
        SimpleTokenizer tokenizer(settings1, *this);
        ASSERT_LOC(tokenizer.tokenize(code), file, line);

        runChecks<CheckCondition>(tokenizer, this);
    }

    void multicompare() {
        check("void foo(int x)\n"
              "{\n"
              "    if (x & 7);\n"
              "    else { if (x == 1); }\n"
              "}");
        ASSERT_EQUALS("[test.cpp:4:18]: (style) Expression is always false because 'else if' condition matches previous condition at line 3. [multiCondition]\n", errout_str());

        check("void foo(int x)\n"
              "{\n"
              "    if (x & 7);\n"
              "    else { if (x & 1); }\n"
              "}");
        ASSERT_EQUALS("[test.cpp:4:18]: (style) Expression is always false because 'else if' condition matches previous condition at line 3. [multiCondition]\n", errout_str());

        check("extern int bar() __attribute__((pure));\n"
              "void foo(int x)\n"
              "{\n"
              "    if ( bar() >1 && b) {}\n"
              "    else if (bar() >1 && b) {}\n"
              "}");
        ASSERT_EQUALS("[test.cpp:5:23]: (style) Expression is always false because 'else if' condition matches previous condition at line 4. [multiCondition]\n", errout_str());

        checkPureFunction("extern int bar();\n"
                          "void foo(int x)\n"
                          "{\n"
                          "    if ( bar() >1 && b) {}\n"
                          "    else if (bar() >1 && b) {}\n"
                          "}");
        ASSERT_EQUALS("[test.cpp:5:23]: (style) Expression is always false because 'else if' condition matches previous condition at line 4. [multiCondition]\n", errout_str());

        // 7284
        check("void foo() {\n"
              "    if (a) {}\n"
              "    else if (!!a) {}\n"
              "}");
        ASSERT_EQUALS("[test.cpp:3:14]: (style) Expression is always false because 'else if' condition matches previous condition at line 2. [multiCondition]\n", errout_str());

        // #11059
        check("int f();\n"
              "void g() {\n"
              "    int i = f();\n"
              "    if (i == 3) {}\n"
              "    else if ((i = f()) == 5) {}\n"
              "    else if (i == 3) {}\n"
              "}\n");
        ASSERT_EQUALS("", errout_str());

        check("int f();\n"
              "void g() {\n"
              "    int i = f();\n"
              "    if (i == 3) {}\n"
              "    else if ((i = f()) == 5) {}\n"
              "    else if (i != 3) {}\n"
              "}\n");
        ASSERT_EQUALS("", errout_str());
    }

    void overlappingElseIfCondition() {
        check("void f(int a, int &b) {\n"
              "    if (a) { b = 1; }\n"
              "    else { if (a) { b = 2; } }\n"
              "}");
        ASSERT_EQUALS("[test.cpp:3:16]: (style) Expression is always false because 'else if' condition matches previous condition at line 2. [multiCondition]\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:3:16]: (style) Expression is always false because 'else if' condition matches previous condition at line 2. [multiCondition]\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:4:18]: (style) Expression is always false because 'else if' condition matches previous condition at line 2. [multiCondition]\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:4:18]: (style) Expression is always false because 'else if' condition matches previous condition at line 3. [multiCondition]\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(Class &c) {\n"
                  "    if (c.dostuff() == 3) {}\n"
                  "    else { if (c.dostuff() == 3) {} }\n"
                  "}");
            ASSERT_EQUALS("", errout_str());

            check("void f(const Class &c) {\n"
                  "    if (c.dostuff() == 3) {}\n"
                  "    else { if (c.dostuff() == 3) {} }\n"
                  "}");
            ASSERT_EQUALS("[test.cpp:3:28]: (style) Expression is always false because 'else if' condition matches previous condition at line 2. [multiCondition]\n", 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(int64_t 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<BUTTON*>(widget)){}\n"
              "  else if (dynamic_cast<LABEL*>(widget)){}\n"
              "}");
        ASSERT_EQUALS("", errout_str());

        check("class B { virtual void v() {} };\n" // #11037
              "class D1 : public B {};\n"
              "class D2 : public B {};\n"
              "void f(const std::shared_ptr<B>&p) {\n"
              "    const auto d1 = dynamic_cast<D1*>(p.get());\n"
              "    const auto d2 = dynamic_cast<D2*>(p.get());\n"
              "    if (d1) {}\n"
              "    else if (d2) {}\n"
              "}\n");
        ASSERT_EQUALS("", errout_str());

        check("void f(int x) {\n" // #6482
              "  if (x & 1) {}\n"
              "  else if (x == 0) {}\n"
              "}");
        ASSERT_EQUALS("", errout_str());

        check("void f(int x) {\n"
              "  if (x & 15) {}\n"
              "  else if (x == 40) {}\n"
              "}");
        ASSERT_EQUALS("[test.cpp:3:14]: (style) Expression is always false because 'else if' condition matches previous condition at line 2. [multiCondition]\n", errout_str());

        check("void f(int x) {\n"
              "  if (x == sizeof(double)) {}\n"
              "  else { if (x == sizeof(long double)) {} }"
              "}");
        ASSERT_EQUALS("", errout_str());

        check("void f(int x) {\n"
              "  if (x & 0x08) {}\n"
              "  else if (x & 0xF8) {}\n"
              "}");
        ASSERT_EQUALS("", errout_str());

        check("void f(int x) {\n"
              "  if (x & 0xF8) {}\n"
              "  else if (x & 0x08) {}\n"
              "}");
        ASSERT_EQUALS("[test.cpp:3:14]: (style) Expression is always false because 'else if' condition matches previous condition at line 2. [multiCondition]\n", errout_str());

        check("void f(bool a, bool b) {\n"
              "   if(a && b){}\n"
              "   else if( !!b && !!a){}\n"
              "}");
        ASSERT_EQUALS("[test.cpp:3:17]: (style) Expression is always false because 'else if' condition matches previous condition at line 2. [multiCondition]\n", errout_str());

        check("void f(bool a, bool b) {\n"
              "   if(a && b){}\n"
              "   else if( !!b && a){}\n"
              "}");
        ASSERT_EQUALS("[test.cpp:3:17]: (style) Expression is always false because 'else if' condition matches previous condition at line 2. [multiCondition]\n", errout_str());

        check("void f(bool a, bool b) {\n"
              "   if(a && b){}\n"
              "   else if( b && !!a){}\n"
              "}");
        ASSERT_EQUALS("[test.cpp:3:15]: (style) Expression is always false because 'else if' condition matches previous condition at line 2. [multiCondition]\n", errout_str());

        check("void f(bool a, bool b) {\n"
              "   if(a && b){}\n"
              "   else if( b && !(!a)){}\n"
              "}");
        ASSERT_EQUALS("[test.cpp:3:15]: (style) Expression is always false because 'else if' condition matches previous condition at line 2. [multiCondition]\n", errout_str());

        check("void f(bool a, bool b) {\n"
              "   if(a && b){}\n"
              "   else if( !!b && !(!a)){}\n"
              "}");
        ASSERT_EQUALS("[test.cpp:3:17]: (style) Expression is always false because 'else if' condition matches previous condition at line 2. [multiCondition]\n", errout_str());

        check("void f(bool a, bool b) {\n"
              "   if(a && b){}\n"
              "   else if( !!(b) && !!(a+b)){}\n"
              "}");
        ASSERT_EQUALS("", errout_str());

        // #8168
        check("enum MaskValues\n"
              "{\n"
              "    Value1 = 0x00000001,\n"
              "    Value2 = 0x00000002\n"
              "};\n"
              "void TestFunction(int value) {\n"
              "    if ( value & (int)Value1 ) {}\n"
              "    else if ( value & (int)Value2 ) {}\n"
              "}");
        ASSERT_EQUALS("", errout_str());

        check("void f(size_t x) {\n"
              "    if (x == sizeof(int)) {}\n"
              "    else { if (x == sizeof(long)) {} }\n"
              "}\n");
        ASSERT_EQUALS("", errout_str());

        check("void f(size_t x) {\n"
              "    if (x == sizeof(long)) {}\n"
              "    else { if (x == sizeof(long long)) {} }\n"
              "}\n");
        ASSERT_EQUALS("", errout_str());
    }

    void oppositeElseIfCondition() {
        setMultiline();

        check("void f(int x) {\n"
              "    if (x) {}\n"
              "    else if (!x) {}\n"
              "}");
        ASSERT_EQUALS("[test.cpp:3:14]: style: Expression is always true because 'else if' condition is opposite to previous condition at line 2. [multiCondition]\n"
                      "[test.cpp:2:9]: note: first condition\n"
                      "[test.cpp:3:14]: note: else if condition is opposite to first condition\n", errout_str());

        check("void f(int x) {\n"
              "    int y = x;\n"
              "    if (x) {}\n"
              "    else if (!y) {}\n"
              "}");
        ASSERT_EQUALS("[test.cpp:4:14]: style: Expression is always true because 'else if' condition is opposite to previous condition at line 3. [multiCondition]\n"
                      "[test.cpp:2:13]: note: 'y' is assigned value 'x' here.\n"
                      "[test.cpp:3:9]: note: first condition\n"
                      "[test.cpp:4:14]: note: else if condition is opposite to first condition\n", errout_str());
    }

    void checkBadBitmaskCheck() {
        check("bool f(int x) {\n"
              "    bool b = x | 0x02;\n"
              "    return b;\n"
              "}");
        ASSERT_EQUALS("[test.cpp:2:16]: (warning) Result of operator '|' is always true if one operand is non-zero. Did you intend to use '&'? [badBitmaskCheck]\n", errout_str());

        check("bool f(int x) {\n"
              "    bool b = 0x02 | x;\n"
              "    return b;\n"
              "}");
        ASSERT_EQUALS("[test.cpp:2:19]: (warning) Result of operator '|' is always true if one operand is non-zero. Did you intend to use '&'? [badBitmaskCheck]\n", errout_str());

        check("int f(int x) {\n"
              "    int b = x | 0x02;\n"
              "    return b;\n"
              "}");
        ASSERT_EQUALS("", errout_str());

        check("bool f(int x) {\n"
              "    bool b = x & 0x02;\n"
              "    return b;\n"
              "}");
        ASSERT_EQUALS("", errout_str());

        check("bool f(int x) {\n"
              "    if(x | 0x02)\n"
              "        return b;\n"
              "}");
        ASSERT_EQUALS("[test.cpp:2:10]: (warning) Result of operator '|' is always true if one operand is non-zero. Did you intend to use '&'? [badBitmaskCheck]\n", errout_str());

        check("bool f(int x) {\n"
              "    int y = 0x1;\n"
              "    if(b) y = 0;\n"
              "    if(x | y)\n"
              "        return b;\n"
              "}");
        ASSERT_EQUALS("", errout_str());

        check("bool f(int x) {\n"
              "    foo(a && (x | 0x02));\n"
              "}");
        ASSERT_EQUALS("[test.cpp:2:17]: (warning) Result of operator '|' is always true if one operand is non-zero. Did you intend to use '&'? [badBitmaskCheck]\n", errout_str());

        check("int f(int x) {\n"
              "    return (x | 0x02) ? 0 : 5;\n"
              "}");
        ASSERT_EQUALS("[test.cpp:2:15]: (warning) Result of operator '|' is always true if one operand is non-zero. Did you intend to use '&'? [badBitmaskCheck]\n", errout_str());

        check("int f(int x) {\n"
              "    return x ? (x | 0x02) : 5;\n"
              "}");
        ASSERT_EQUALS("", errout_str());

        check("bool f(int x) {\n"
              "    return x | 0x02;\n"
              "}");
        ASSERT_EQUALS("[test.cpp:2:14]: (warning) Result of operator '|' is always true if one operand is non-zero. Did you intend to use '&'? [badBitmaskCheck]\n", errout_str());

        check("bool f(int x) {\n"
              "  if (x) {\n"
              "    return x | 0x02;\n"
              "  }\n"
              "  return 0;\n"
              "}");
        ASSERT_EQUALS("[test.cpp:3:14]: (warning) Result of operator '|' is always true if one operand is non-zero. Did you intend to use '&'? [badBitmaskCheck]\n", errout_str());

        check("const bool f(int x) {\n"
              "    return x | 0x02;\n"
              "}");
        ASSERT_EQUALS("[test.cpp:2:14]: (warning) Result of operator '|' is always true if one operand is non-zero. Did you intend to use '&'? [badBitmaskCheck]\n", errout_str());

        check("struct F {\n"
              "  static const bool f(int x) {\n"
              "      return x | 0x02;\n"
              "  }\n"
              "};");
        ASSERT_EQUALS("[test.cpp:3:16]: (warning) Result of operator '|' is always true if one operand is non-zero. Did you intend to use '&'? [badBitmaskCheck]\n", errout_str());

        check("struct F {\n"
              "  typedef bool b_t;\n"
              "};\n"
              "F::b_t f(int x) {\n"
              "  return x | 0x02;\n"
              "}");
        ASSERT_EQUALS("[test.cpp:5:12]: (warning) Result of operator '|' is always true if one operand is non-zero. Did you intend to use '&'? [badBitmaskCheck]\n", errout_str());

        check("int f(int x) {\n"
              "    return x | 0x02;\n"
              "}");
        ASSERT_EQUALS("", errout_str());

        check("void create_rop_masks_4( rop_mask_bits *bits) {\n"
              "DWORD mask_offset;\n"
              "BYTE *and_bits = bits->and;\n"
              "rop_mask *rop_mask;\n"
              "and_bits[mask_offset] |= (rop_mask->and & 0x0f);\n"
              "}");
        ASSERT_EQUALS("", errout_str());

        check("void f(unsigned a, unsigned b) {\n"
              "  unsigned cmd1 = b & 0x0F;\n"
              "  if (cmd1 | a) {\n"
              "    if (b == 0x0C) {}\n"
              "  }\n"
              "}");
        ASSERT_EQUALS("", errout_str());

        check("void f(int i) {\n" // #11082
              "    int j = 0;\n"
              "    if (i | j) {}\n"
              "}\n");
        ASSERT_EQUALS("[test.cpp:3:11]: (style) Operator '|' with one operand equal to zero is redundant. [badBitmaskCheck]\n", errout_str());

        check("#define EIGHTTOIS(x) (((x) << 8) | (x))\n"
              "int f() {\n"
              "    return EIGHTTOIS(0);\n"
              "}\n");
        ASSERT_EQUALS("", errout_str());

        check("#define O_RDONLY 0\n"
              "void f(const char* s, int* pFd) {\n"
              "    *pFd = open(s, O_RDONLY | O_BINARY, 0);\n"
              "}\n");
        ASSERT_EQUALS("", errout_str());

        check("const int FEATURE_BITS = x |\n"
              "#if FOO_ENABLED\n"
              "    FEATURE_FOO |\n"
              "#endif\n"
              "#if BAR_ENABLED\n"
              "    FEATURE_BAR |\n"
              "#endif\n"
              "    0;");
        ASSERT_EQUALS("", errout_str());

        check("enum precedence { PC0, UNARY };\n"
              "int x = PC0   | UNARY;\n"
              "int y = UNARY | PC0;\n");
        ASSERT_EQUALS("", errout_str());

        check("#define MASK 0\n"
              "#define SHIFT 1\n"
              "int x = 1 | (MASK << SHIFT);\n");
        ASSERT_EQUALS("", errout_str());
    }


    void incorrectLogicOperator1() {
        check("void f(int x) {\n"
              "    if ((x != 1) || (x != 3))\n"
              "        a++;\n"
              "}");
        ASSERT_EQUALS("[test.cpp:2:18]: (warning) Logical disjunction always evaluates to true: x != 1 || x != 3. [incorrectLogicOperator]\n", errout_str());

        check("void f(int x) {\n"
              "    if (1 != x || 3 != x)\n"
              "        a++;\n"
              "}");
        ASSERT_EQUALS("[test.cpp:2:16]: (warning) Logical disjunction always evaluates to true: x != 1 || x != 3. [incorrectLogicOperator]\n", errout_str());

        check("void f(int x) {\n"
              "  if (x<0 && !x) {}\n"
              "}");
        ASSERT_EQUALS("[test.cpp:2:11]: (warning) Logical conjunction always evaluates to false: x < 0 && !x. [incorrectLogicOperator]\n", errout_str());

        check("void f(int x) {\n"
              "  if (x==0 && x) {}\n"
              "}");
        ASSERT_EQUALS("[test.cpp:2:12]: (warning) Logical conjunction always evaluates to false: x == 0 && x. [incorrectLogicOperator]\n", errout_str());

        check("void f(int x) {\n" // ast..
              "    if (y == 1 && x == 1 && x == 7) { }\n"
              "}");
        ASSERT_EQUALS("[test.cpp:2:26]: (warning) Logical conjunction always evaluates to false: x == 1 && x == 7. [incorrectLogicOperator]\n", errout_str());

        check("void f(int x, int y) {\n"
              "    if (x != 1 || y != 1)\n"
              "        a++;\n"
              "}");
        ASSERT_EQUALS("", errout_str());

        check("void f(int x, int y) {\n"
              "    if ((y == 1) && (x != 1) || (x != 3))\n"
              "        a++;\n"
              "}");
        ASSERT_EQUALS("", errout_str());

        check("void f(int x, int y) {\n"
              "    if ((x != 1) || (x != 3) && (y == 1))\n"
              "        a++;\n"