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Fix 10578: Value not impossible after check (#3549)

This commit is contained in:
Paul Fultz II 2021-11-07 11:19:56 -06:00 committed by GitHub
parent a50596df72
commit 035c70c441
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GPG Key ID: 4AEE18F83AFDEB23
7 changed files with 66 additions and 13 deletions
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11
lib/astutils.cpp
View File

@ -215,6 +215,14 @@ bool astIsGenericChar(const Token* tok)
return !astIsPointer(tok) && tok && tok->valueType() && (tok->valueType()->type == ValueType::Type::CHAR || tok->valueType()->type == ValueType::Type::WCHAR_T);
}
bool astIsPrimitive(const Token* tok)
{
const ValueType* vt = tok ? tok->valueType() : nullptr;
if (!vt)
return false;
return vt->isPrimitive();
}
bool astIsIntegral(const Token *tok, bool unknown)
{
const ValueType *vt = tok ? tok->valueType() : nullptr;
@ -1950,6 +1958,9 @@ bool isVariableChangedByFunctionCall(const Token *tok, int indirect, const Setti
return false;
if (tok->isKeyword() && !isCPPCastKeyword(tok) && tok->str().compare(0,8,"operator") != 0)
return false;
// A functional cast won't modify the variable
if (Token::Match(tok, "%type% (|{") && tok->tokType() == Token::eType && astIsPrimitive(tok->next()))
return false;
const Token * parenTok = tok->next();
if (Token::simpleMatch(parenTok, "<") && parenTok->link())
parenTok = parenTok->link()->next();

1
lib/astutils.h
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@ -64,6 +64,7 @@ bool astHasToken(const Token* root, const Token * tok);
bool astHasVar(const Token * tok, nonneg int varid);
bool astIsPrimitive(const Token* tok);
/** Is expression a 'signed char' if no promotion is used */
bool astIsSignedChar(const Token *tok);
/** Is expression a 'char' if no promotion is used? */

22
lib/checkio.cpp
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@ -973,6 +973,10 @@ void CheckIO::checkFormatString(const Token * const tok,
std::string specifier;
bool done = false;
while (!done) {
if (i == formatString.end()) {
done = true;
break;
}
switch (*i) {
case 's':
if (argListTok->tokType() != Token::eString &&
@ -1242,7 +1246,7 @@ void CheckIO::checkFormatString(const Token * const tok,
case 'h': // Can be 'hh' (signed char or unsigned char) or 'h' (short int or unsigned short int)
case 'l': { // Can be 'll' (long long int or unsigned long long int) or 'l' (long int or unsigned long int)
// If the next character is the same (which makes 'hh' or 'll') then expect another alphabetical character
if (i != formatString.end() && (i + 1) != formatString.end() && *(i + 1) == *i) {
if ((i + 1) != formatString.end() && *(i + 1) == *i) {
if ((i + 2) != formatString.end() && !isalpha(*(i + 2))) {
std::string modifier;
modifier += *i;
@ -1254,17 +1258,13 @@ void CheckIO::checkFormatString(const Token * const tok,
specifier += *i++;
}
} else {
if (i != formatString.end()) {
if ((i + 1) != formatString.end() && !isalpha(*(i + 1))) {
std::string modifier;
modifier += *i;
invalidLengthModifierError(tok, numFormat, modifier);
done = true;
} else {
specifier = *i++;
}
} else {
if ((i + 1) != formatString.end() && !isalpha(*(i + 1))) {
std::string modifier;
modifier += *i;
invalidLengthModifierError(tok, numFormat, modifier);
done = true;
} else {
specifier = *i++;
}
}
}

9
lib/reverseanalyzer.cpp
View File

@ -263,6 +263,15 @@ struct ReverseTraversal {
tok = parent;
continue;
}
if (tok->str() == "case") {
const Scope* scope = tok->scope();
while (scope && scope->type != Scope::eSwitch)
scope = scope->nestedIn;
if (!scope || scope->type != Scope::eSwitch)
break;
tok = tok->tokAt(scope->bodyStart->index() - tok->index() - 1);
continue;
}
if (!update(tok))
break;
}

2
lib/symboldatabase.cpp
View File

@ -6504,6 +6504,8 @@ void SymbolDatabase::setValueTypeInTokenList(bool reportDebugWarnings, Token *to
valuetype.sign = ValueType::Sign::UNSIGNED;
else if (tok->previous()->isSigned())
valuetype.sign = ValueType::Sign::SIGNED;
else if (valuetype.isIntegral() && valuetype.type != ValueType::UNKNOWN_INT)
valuetype.sign = mDefaultSignedness;
setValueType(tok, valuetype);
}

11
lib/valueflow.cpp
View File

@ -356,7 +356,13 @@ static void combineValueProperties(const ValueFlow::Value &value1, const ValueFl
static const Token *getCastTypeStartToken(const Token *parent)
{
// TODO: This might be a generic utility function?
if (!parent || parent->str() != "(")
if (!Token::Match(parent, "{|("))
return nullptr;
// Functional cast
if (parent->isBinaryOp() && Token::Match(parent->astOperand1(), "%type% (|{") &&
parent->astOperand1()->tokType() == Token::eType && astIsPrimitive(parent))
return parent->astOperand1();
if (parent->str() != "(")
return nullptr;
if (!parent->astOperand2() && Token::Match(parent,"( %name%"))
return parent->next();
@ -2328,6 +2334,9 @@ struct ValueFlowAnalyzer : Analyzer {
} else if (getSettings()->library.getFunction(tok)) {
// Assume library function doesn't modify user-global variables
return Action::None;
// Function cast does not modify global variables
} else if (tok->tokType() == Token::eType && astIsPrimitive(tok->next())) {
return Action::None;
} else {
return Action::Invalid;
}

23
test/testvalueflow.cpp
View File

@ -516,6 +516,12 @@ private:
return values;
}
std::list<ValueFlow::Value> removeImpossible(std::list<ValueFlow::Value> values)
{
values.remove_if(std::mem_fn(&ValueFlow::Value::isImpossible));
return values;
}
void valueFlowNumber() {
ASSERT_EQUALS(123, valueOfTok("x=123;", "123").intvalue);
ASSERT_EQUALS_DOUBLE(192.0, valueOfTok("x=0x0.3p10;", "0x0.3p10").floatValue, 1e-5); // 3 * 16^-1 * 2^10 = 192
@ -3015,7 +3021,22 @@ private:
" return 0; \n"
"}\n";
ASSERT_EQUALS(true, testValueOfX(code, 6U, 63));
TODO_ASSERT_EQUALS(true, false, testValueOfXImpossible(code, 6U, 64));
ASSERT_EQUALS(true, testValueOfXImpossible(code, 6U, 64));
code = "long long f(const long long& x, const long long& y) {\n"
" switch (s) {\n"
" case 0:\n"
" if (x >= 64)\n"
" return 0;\n"
" return long long{y} << long long{x};\n"
" case 1:\n"
" if (x >= 64) {\n"
" }\n"
" }\n"
" return 0; \n"
"}\n";
ASSERT_EQUALS(true, testValueOfX(code, 6U, 63));
ASSERT_EQUALS(true, testValueOfXImpossible(code, 6U, 64));
code = "int g(int x) { throw 0; }\n"
"void f(int x) {\n"