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Fixed #9906 (False positive: constParameter (function pointer))

This commit is contained in:
Daniel Marjamäki 2020-09-23 22:10:47 +02:00
parent dae37f1c9f
commit 514b7f4da4
5 changed files with 75 additions and 24 deletions
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28
lib/checkother.cpp
View File

@ -1349,7 +1349,7 @@ void CheckOther::checkConstVariable()
const Scope *scope = var->scope();
if (!scope->function)
continue;
Function *function = scope->function;
const Function *function = scope->function;
if (var->isArgument()) {
if (function->isImplicitlyVirtual() || function->templateDef)
continue;
@ -1427,22 +1427,26 @@ void CheckOther::checkConstVariable()
continue;
}
constVariableError(var);
constVariableError(var, function);
}
}
void CheckOther::constVariableError(const Variable *var)
void CheckOther::constVariableError(const Variable *var, const Function *function)
{
const Token *tok = nullptr;
std::string name = "x";
std::string id = "Variable";
if (var) {
tok = var->nameToken();
name = var->name();
if (var->isArgument())
id = "Parameter";
const std::string vartype((var && var->isArgument()) ? "Parameter" : "Variable");
const std::string varname(var ? var->name() : std::string("x"));
ErrorPath errorPath;
std::string id = "const" + vartype;
std::string message = "$symbol:" + varname + "\n" + vartype + " '$symbol' can be declared with const";
errorPath.push_back(ErrorPathItem(var ? var->nameToken() : nullptr, message));
if (var && var->isArgument() && function && function->functionPointerUsage) {
errorPath.push_back(ErrorPathItem(function->functionPointerUsage, "You might need to cast the function pointer here"));
id += "Callback";
message += ". However it seems that '" + function->name() + "' is a callback function, if '$symbol' is declared with const you might also need to cast function pointer(s).";
}
reportError(tok, Severity::style, "const" + id, id + " '" + name + "' can be declared with const", CWE398, false);
reportError(errorPath, Severity::style, id.c_str(), message, CWE398, false);
}
//---------------------------------------------------------------------------

5
lib/checkother.h
View File

@ -38,6 +38,7 @@ namespace ValueFlow {
class Settings;
class Token;
class Tokenizer;
class Function;
class Variable;
class ErrorLogger;
@ -229,7 +230,7 @@ private:
void cstyleCastError(const Token *tok);
void invalidPointerCastError(const Token* tok, const std::string& from, const std::string& to, bool inconclusive, bool toIsInt);
void passedByValueError(const Token *tok, const std::string &parname, bool inconclusive);
void constVariableError(const Variable *var);
void constVariableError(const Variable *var, const Function *function);
void constStatementError(const Token *tok, const std::string &type, bool inconclusive);
void signedCharArrayIndexError(const Token *tok);
void unknownSignCharArrayIndexError(const Token *tok);
@ -301,7 +302,7 @@ private:
c.checkCastIntToCharAndBackError(nullptr, "func_name");
c.cstyleCastError(nullptr);
c.passedByValueError(nullptr, "parametername", false);
c.constVariableError(nullptr);
c.constVariableError(nullptr, nullptr);
c.constStatementError(nullptr, "type", false);
c.signedCharArrayIndexError(nullptr);
c.unknownSignCharArrayIndexError(nullptr);

40
lib/symboldatabase.cpp
View File

@ -1053,10 +1053,26 @@ void SymbolDatabase::createSymbolDatabaseSetFunctionPointers(bool firstPass)
// Set function call pointers
for (const Token* tok = mTokenizer->list.front(); tok != mTokenizer->list.back(); tok = tok->next()) {
if (!tok->function() && tok->varId() == 0 && tok->linkAt(1) && Token::Match(tok, "%name% (") && !isReservedName(tok->str())) {
if (tok->isName() && !tok->function() && tok->varId() == 0 && Token::Match(tok, "%name% [(,)>]") && !isReservedName(tok->str())) {
if (tok->next()->str() == ">" && !tok->next()->link())
continue;
if (tok->next()->str() != "(") {
const Token *start = tok;
while (Token::Match(start->tokAt(-2), "%name% ::"))
start = start->tokAt(-2);
if (!Token::Match(start->previous(), "[(,<]") && !Token::Match(start->tokAt(-2), "[(,<] &"))
continue;
}
const Function *function = findFunction(tok);
if (function)
const_cast<Token *>(tok)->function(function);
if (!function)
continue;
const_cast<Token *>(tok)->function(function);
if (tok->next()->str() != "(")
const_cast<Function *>(function)->functionPointerUsage = tok;
}
}
@ -2063,6 +2079,7 @@ Function::Function(const Tokenizer *mTokenizer,
noexceptArg(nullptr),
throwArg(nullptr),
templateDef(nullptr),
functionPointerUsage(nullptr),
mFlags(0)
{
// operator function
@ -2211,6 +2228,7 @@ Function::Function(const Token *tokenDef)
noexceptArg(nullptr),
throwArg(nullptr),
templateDef(nullptr),
functionPointerUsage(nullptr),
mFlags(0)
{
}
@ -4602,10 +4620,7 @@ static std::string getTypeString(const Token *typeToken)
const Function* Scope::findFunction(const Token *tok, bool requireConst) const
{
// make sure this is a function call
const Token *end = tok->linkAt(1);
if (!end)
return nullptr;
const bool isCall = Token::Match(tok->next(), "(|{");
const std::vector<const Token *> arguments = getArguments(tok);
@ -4617,7 +4632,7 @@ const Function* Scope::findFunction(const Token *tok, bool requireConst) const
auto addMatchingFunctions = [&](const Scope *scope) {
for (std::multimap<std::string, const Function *>::const_iterator it = scope->functionMap.find(tok->str()); it != scope->functionMap.cend() && it->first == tok->str(); ++it) {
const Function *func = it->second;
if (args == func->argCount() ||
if (!isCall || args == func->argCount() ||
(func->isVariadic() && args >= (func->argCount() - 1)) ||
(args < func->argCount() && args >= func->minArgCount())) {
matches.push_back(func);
@ -4636,6 +4651,11 @@ const Function* Scope::findFunction(const Token *tok, bool requireConst) const
// check in base classes
findFunctionInBase(tok->str(), args, matches);
// Non-call => Do not match parameters
if (!isCall) {
return matches.empty() ? nullptr : matches[0];
}
const Function* fallback1Func = nullptr;
const Function* fallback2Func = nullptr;
@ -4862,8 +4882,8 @@ const Function* SymbolDatabase::findFunction(const Token *tok) const
}
if (currScope) {
while (currScope && !(Token::Match(tok1, "%type% :: %any% (") ||
(Token::Match(tok1, "%type% <") && Token::Match(tok1->linkAt(1), "> :: %any% (")))) {
while (currScope && !(Token::Match(tok1, "%type% :: %name% [(),>]") ||
(Token::Match(tok1, "%type% <") && Token::Match(tok1->linkAt(1), "> :: %name% (")))) {
if (tok1->strAt(1) == "::")
tok1 = tok1->tokAt(2);
else

1
lib/symboldatabase.h
View File

@ -900,6 +900,7 @@ public:
const Token *noexceptArg; ///< noexcept token
const Token *throwArg; ///< throw token
const Token *templateDef; ///< points to 'template <' before function
const Token *functionPointerUsage; ///< function pointer usage
static bool argsMatch(const Scope *scope, const Token *first, const Token *second, const std::string &path, nonneg int path_length);

25
test/testother.cpp
View File

@ -98,6 +98,7 @@ private:
TEST_CASE(passedByValue_externC);
TEST_CASE(constVariable);
TEST_CASE(constParameterCallback);
TEST_CASE(switchRedundantAssignmentTest);
TEST_CASE(switchRedundantOperationTest);
@ -2522,6 +2523,30 @@ private:
TODO_ASSERT_EQUALS("[test.cpp:16]: (style) Parameter 'i' can be declared with const\n", "", errout.str());
}
void constParameterCallback() {
check("int callback(std::vector<int>& x) { return x[0]; }\n"
"void f() { dostuff(callback); }");
ASSERT_EQUALS("[test.cpp:1] -> [test.cpp:2]: (style) Parameter 'x' can be declared with const. However it seems that 'callback' is a callback function, if 'x' is declared with const you might also need to cast function pointer(s).\n", errout.str());
// #9906
check("class EventEngine : public IEventEngine {\n"
"public:\n"
" EventEngine();\n"
"\n"
"private:\n"
" void signalEvent(ev::sig& signal, int revents);\n"
"};\n"
"\n"
"EventEngine::EventEngine() {\n"
" mSigWatcher.set<EventEngine, &EventEngine::signalEvent>(this);\n"
"}\n"
"\n"
"void EventEngine::signalEvent(ev::sig& signal, int revents) {\n"
" switch (signal.signum) {}\n"
"}");
ASSERT_EQUALS("[test.cpp:13] -> [test.cpp:10]: (style) Parameter 'signal' can be declared with const. However it seems that 'signalEvent' is a callback function, if 'signal' is declared with const you might also need to cast function pointer(s).\n", errout.str());
}
void switchRedundantAssignmentTest() {
check("void foo()\n"
"{\n"