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1279 lines (1098 loc) · 49 KB
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/*
* Cppcheck - A tool for static C/C++ code analysis
* Copyright (C) 2007-2015 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 <http://www.gnu.org/licenses/>.
*/
#include "tokenize.h"
#include "checkcondition.h"
#include "testsuite.h"
#include <sstream>
#include <tinyxml2.h>
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<WS_CHILD|WS_VISIBLE>..
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());
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]: (style) Expression is always false because 'else if' condition matches previous condition at line 4.\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]: (style) Expression is always false because 'else if' condition matches previous condition at line 4.\n", errout.str());
}
void checkPureFunction(const char code[]) {
// Clear the error buffer..
errout.str("");
const char cfg[] = "<?xml version=\"1.0\"?>\n"
"<def>\n"
" <function name=\"bar\"> <pure/> </function>\n"
"</def>";
tinyxml2::XMLDocument xmldoc;
xmldoc.Parse(cfg, sizeof(cfg));
Settings settings;
settings.addEnabled("style");
settings.addEnabled("warning");
settings.library.load(xmldoc);
// Tokenize..
Tokenizer tokenizer(&settings, this);
std::istringstream istr(code);
tokenizer.tokenize(istr, "test.cpp");
CheckCondition checkCondition;
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 (str1 != str2) {
warnUnsimplified(str1, str2);
}
}
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<BUTTON*>(widget)){}\n"
" else if (dynamic_cast<LABEL*>(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"
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