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Taking care of operation overloading functions #958

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Taking care of operation overloading functions #958

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59 changes: 53 additions & 6 deletions lib/checkunusedfunctions.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -235,6 +235,49 @@ void CheckUnusedFunctions::parseTokens(const Tokenizer &tokenizer, const char Fi
}


static bool isOperatorFunction(const std::string & funcName) {
/* Operator functions are invalid function names for C, so no need to check
* this in here. As result the returned error function might be incorrect.
*
* List of valid operators can be found at:
* http://en.cppreference.com/w/cpp/language/operators
*
* Conversion functions must be a member function (at least for gcc), so no
* need to cover them for unused functions
*
* Literal functions are treated at a different place, so no check is done
* in here
*/
const std::string operatorPrefix = "operator";
if (funcName.compare(0, operatorPrefix.length(), operatorPrefix) != 0) {
return false;
}

std::string opName = funcName.substr(operatorPrefix.length());

/* Operation overload + allocation/deallocation
*
* Don't treat the following, as they have to be a member function:
* '=', '()', '[]', '->', '->*'
*/
const std::vector<std::string> knownOperators = {
"+", "-", "*", "/", "%", "&", "|", "~", "!", "<", ">", "+=", "-=",
"*=", "/=", "%=", "^=", "&=", "|=", "<<", ">>", ">>=", "<<=", "==",
"!=", "<=", ">=", "&&", "||", "++", "--", ",",
// Allocation variants; space is delete within the simplification
"new", "new[]",
// Deallocation variants; space is delete within the simplification
"delete", "delete[]"
};
for (auto const & curOp : knownOperators) {
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@danmar danmar Oct 19, 2017 •
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please don't use a ranged for loop. That is C++11. It seems clumpsy to check for every known operator. If opName is any operator (!std::isalnum(opName[0] && opName[0] != '_')) then I think this function could return true.

if (curOp == opName) {
return true;
}
}

return false;
}



void CheckUnusedFunctions::check(ErrorLogger * const errorLogger, const Settings& settings)
Expand All @@ -248,10 +291,12 @@ void CheckUnusedFunctions::check(ErrorLogger * const errorLogger, const Settings
it->first == "if")
continue;
if (!func.usedSameFile) {
std::string filename;
if (func.filename != "+")
filename = func.filename;
unusedFunctionError(errorLogger, filename, func.lineNumber, it->first);
if (!isOperatorFunction(it->first)) {
std::string filename;
if (func.filename != "+")
filename = func.filename;
unusedFunctionError(errorLogger, filename, func.lineNumber, it->first);
}
} else if (! func.usedOtherFile) {
/** @todo add error message "function is only used in <file> it can be static" */
/*
Expand Down Expand Up @@ -382,8 +427,10 @@ void CheckUnusedFunctions::analyseWholeProgram(ErrorLogger * const errorLogger,
continue;

if (calls.find(functionName) == calls.end()) {
const Location &loc = decl->second;
unusedFunctionError(errorLogger, loc.fileName, loc.lineNumber, functionName);
if (!isOperatorFunction(functionName)) {
const Location &loc = decl->second;
unusedFunctionError(errorLogger, loc.fileName, loc.lineNumber, functionName);
}
}
}
}
65 changes: 65 additions & 0 deletions test/testunusedfunctions.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -61,6 +61,8 @@ class TestUnusedFunctions : public TestFixture {
TEST_CASE(lineNumber); // Ticket 3059

TEST_CASE(ignore_declaration); // ignore declaration

TEST_CASE(operatorOverload);
}

void check(const char code[], Settings::PlatformType platform = Settings::Native) {
Expand Down Expand Up @@ -386,6 +388,69 @@ class TestUnusedFunctions : public TestFixture {
"void (*list[])(void) = {f}");
ASSERT_EQUALS("", errout.str());
}

void operatorOverload() {
check("class A {\n"
"private:\n"
" friend std::ostream & operator<<(std::ostream &, const A&);\n"
"};\n"
"std::ostream & operator<<(std::ostream &os, const A&) {\n"
" os << \"This is class A\";\n"
"}");
ASSERT_EQUALS("", errout.str());

check("class A{};\n"
"A operator + (const A &, const A &){ return A(); }\n"
"A operator - (const A &, const A &){ return A(); }\n"
"A operator * (const A &, const A &){ return A(); }\n"
"A operator / (const A &, const A &){ return A(); }\n"
"A operator % (const A &, const A &){ return A(); }\n"
"A operator & (const A &, const A &){ return A(); }\n"
"A operator | (const A &, const A &){ return A(); }\n"
"A operator ~ (const A &){ return A(); }\n"
"A operator ! (const A &){ return A(); }\n"
"bool operator < (const A &, const A &){ return true; }\n"
"bool operator > (const A &, const A &){ return true; }\n"
"A operator += (const A &, const A &){ return A(); }\n"
"A operator -= (const A &, const A &){ return A(); }\n"
"A operator *= (const A &, const A &){ return A(); }\n"
"A operator /= (const A &, const A &){ return A(); }\n"
"A operator %= (const A &, const A &){ return A(); }\n"
"A operator &= (const A &, const A &){ return A(); }\n"
"A operator ^= (const A &, const A &){ return A(); }\n"
"A operator |= (const A &, const A &){ return A(); }\n"
"A operator << (const A &, const int){ return A(); }\n"
"A operator >> (const A &, const int){ return A(); }\n"
"A operator <<= (const A &, const int){ return A(); }\n"
"A operator >>= (const A &, const int){ return A(); }\n"
"bool operator == (const A &, const A &){ return true; }\n"
"bool operator != (const A &, const A &){ return true; }\n"
"bool operator <= (const A &, const A &){ return true; }\n"
"bool operator >= (const A &, const A &){ return true; }\n"
"A operator && (const A &, const int){ return A(); }\n"
"A operator || (const A &, const int){ return A(); }\n"
"A operator ++ (const A &, const int){ return A(); }\n"
"A operator ++ (const A &){ return A(); }\n"
"A operator -- (const A &, const int){ return A(); }\n"
"A operator -- (const A &){ return A(); }\n"
"A operator , (const A &, const A &){ return A(); }\n");
ASSERT_EQUALS("", errout.str());


check("class A {\n"
"public:\n"
" static void * operator new(std::size_t);\n"
" static void * operator new[](std::size_t);\n"
"};\n"
"void * A::operator new(std::size_t s) {\n"
" return malloc(s);\n"
"}\n"
"void * A::operator new[](std::size_t s) {\n"
" return malloc(s);\n"
"}");
ASSERT_EQUALS("", errout.str());
}

};

REGISTER_TEST(TestUnusedFunctions)