cppcheck/lib/checkvaarg.cpp at master · encryptacoder/cppcheck · GitHub

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* Cppcheck - A tool for static C/C++ code analysis

* 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 "checkvaarg.h"

#include "symboldatabase.h"

//---------------------------------------------------------------------------

// Register this check class (by creating a static instance of it)

namespace {

CheckVaarg instance;

}

//---------------------------------------------------------------------------

// Ensure that correct parameter is passed to va_start()

//---------------------------------------------------------------------------

void CheckVaarg::va_start_argument()

{

const SymbolDatabase* const symbolDatabase = _tokenizer->getSymbolDatabase();

const std::size_t functions = symbolDatabase->functionScopes.size();

for (std::size_t i = 0; i < functions; ++i) {

const Scope* scope = symbolDatabase->functionScopes[i];

const Function* function = scope->function;

for (const Token* tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {

if (!tok->scope()->isExecutable())

tok = tok->scope()->classEnd;

else if (Token::simpleMatch(tok, "va_start (")) {

const Token* param2 = tok->tokAt(2)->nextArgument();

if (!param2)

continue;

const Variable* var = param2->variable();

if (var && var->isReference())

referenceAs_va_start_error(param2, var->name());

if (var && var->index() + 2 < function->argCount() && _settings->isEnabled("warning")) {

std::list<Variable>::const_reverse_iterator it = function->argumentList.rbegin();

++it;

wrongParameterTo_va_start_error(tok, var->name(), it->name());

}

tok = tok->linkAt(1);

}

void CheckVaarg::wrongParameterTo_va_start_error(const Token *tok, const std::string& paramIsName, const std::string& paramShouldName)

{

reportError(tok, Severity::warning,

"va_start_wrongParameter", "'" + paramIsName + "' given to va_start() is not last named argument of the function. Did you intend to pass '" + paramShouldName + "'?");

}

void CheckVaarg::referenceAs_va_start_error(const Token *tok, const std::string& paramName)

{

reportError(tok, Severity::error,

"va_start_referencePassed", "Using reference '" + paramName + "' as parameter for va_start() results in undefined behaviour.");

}

//---------------------------------------------------------------------------

// Detect missing va_end() if va_start() was used

// Detect va_list usage after va_end()

//---------------------------------------------------------------------------

void CheckVaarg::va_list_usage()

{

const SymbolDatabase* const symbolDatabase = _tokenizer->getSymbolDatabase();

for (unsigned int varid = 1; varid < symbolDatabase->getVariableListSize(); varid++) {

const Variable* var = symbolDatabase->getVariableFromVarId(varid);

if (!var || var->isPointer() || var->isReference() || var->isArray() || !var->scope() || var->typeStartToken()->str() != "va_list")

continue;

if (!var->isLocal() && !var->isArgument()) // Check only local variables and arguments

continue;

bool open = var->isArgument(); // va_list passed as argument are opened

bool exitOnEndOfStatement = false;

const Token* tok = var->nameToken()->next();

for (; tok != var->scope()->classEnd; tok = tok->next()) {

if (Token::Match(tok, "va_start ( %varid%", var->declarationId())) {

if (open)

va_start_subsequentCallsError(tok, var->name());

open = true;

tok = tok->linkAt(1);

} else if (Token::Match(tok, "va_end ( %varid%", var->declarationId())) {

if (!open)

va_list_usedBeforeStartedError(tok, var->name());

open = false;

tok = tok->linkAt(1);

} else if (Token::simpleMatch(tok, "va_copy (")) {

bool nopen = open;

if (tok->linkAt(1)->previous()->varId() == var->declarationId()) { // Source

if (!open)

va_list_usedBeforeStartedError(tok, var->name());

}

if (tok->tokAt(2)->varId() == var->declarationId()) { // Destination

if (open)

va_start_subsequentCallsError(tok, var->name());

nopen = true;

}

open = nopen;

tok = tok->linkAt(1);

} else if (Token::Match(tok, "throw|return"))

exitOnEndOfStatement = true;

else if (_tokenizer->isCPP() && tok->str() == "try") {

open = false;

break;

} else if (!open && tok->varId() == var->declarationId())

va_list_usedBeforeStartedError(tok, var->name());

else if (exitOnEndOfStatement && tok->str() == ";")

break;

}

if (open && !var->isArgument())

va_end_missingError(tok, var->name());

}

void CheckVaarg::va_end_missingError(const Token *tok, const std::string& varname)

{

reportError(tok, Severity::error,

"va_end_missing", "va_list '" + varname + "' was opened but not closed by va_end().");

}

void CheckVaarg::va_list_usedBeforeStartedError(const Token *tok, const std::string& varname)

{

reportError(tok, Severity::error,

"va_list_usedBeforeStarted", "va_list '" + varname + "' used before va_start() was called.");

}

void CheckVaarg::va_start_subsequentCallsError(const Token *tok, const std::string& varname)

{

reportError(tok, Severity::error,

"va_start_subsequentCalls", "va_start() or va_copy() called subsequently on '" + varname + "' without va_end() inbetween.");

}

cppcheck/lib/checkvaarg.cpp at master · encryptacoder/cppcheck · GitHub

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