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Fixed #9909 (False positive: knownArgument for calculation 'self->maxsize * sizeof(intptr_t)')

This commit is contained in:
Daniel Marjamäki 2020-09-21 20:02:55 +02:00
parent bca3605f77
commit 107ee57e7a
3 changed files with 31 additions and 14 deletions
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23
lib/checkother.cpp
View File

@ -3113,13 +3113,18 @@ void CheckOther::checkKnownArgument()
if (isVariableExpression(tok2))
continue;
// ensure that there is a integer variable in expression with unknown value
bool intvar = false;
visitAstNodes(tok, [&intvar](const Token *child) {
if (child->varId() && child->valueType() && child->valueType()->isIntegral() && child->values().empty())
intvar = true;
std::string varexpr;
visitAstNodes(tok, [&varexpr](const Token *child) {
if (Token::Match(child, "%var%|.|[")) {
if (child->valueType() && child->valueType()->isIntegral() && child->values().empty()) {
varexpr = child->expressionString();
return ChildrenToVisit::done;
}
return ChildrenToVisit::none;
}
return ChildrenToVisit::op1_and_op2;
});
if (!intvar)
if (varexpr.empty())
continue;
// ensure that function name does not contain "assert"
std::string funcname = tok->astParent()->previous()->str();
@ -3128,18 +3133,18 @@ void CheckOther::checkKnownArgument()
});
if (funcname.find("assert") != std::string::npos)
continue;
knownArgumentError(tok, tok->astParent()->previous(), &tok->values().front());
knownArgumentError(tok, tok->astParent()->previous(), &tok->values().front(), varexpr);
}
}
}
void CheckOther::knownArgumentError(const Token *tok, const Token *ftok, const ValueFlow::Value *value)
void CheckOther::knownArgumentError(const Token *tok, const Token *ftok, const ValueFlow::Value *value, const std::string &varexpr)
{
MathLib::bigint intvalue = value ? value->intvalue : 0;
const std::string expr = tok ? tok->expressionString() : std::string("x");
const std::string expr = tok ? tok->expressionString() : varexpr;
const std::string fun = ftok ? ftok->str() : std::string("f");
const std::string errmsg = "Argument '" + expr + "' to function " + fun + " is always " + std::to_string(intvalue);
const std::string errmsg = "Argument '" + expr + "' to function " + fun + " is always " + std::to_string(intvalue) + ". It does not matter what value '" + varexpr + "' has.";
const ErrorPath errorPath = getErrorPath(tok, value, errmsg);
reportError(errorPath, Severity::style, "knownArgument", errmsg, CWE570, false);
}

7
lib/checkother.h
View File

@ -273,7 +273,7 @@ private:
void funcArgNamesDifferent(const std::string & functionName, nonneg int index, const Token* declaration, const Token* definition);
void funcArgOrderDifferent(const std::string & functionName, const Token * declaration, const Token * definition, const std::vector<const Token*> & declarations, const std::vector<const Token*> & definitions);
void shadowError(const Token *var, const Token *shadowed, std::string type);
void knownArgumentError(const Token *tok, const Token *ftok, const ValueFlow::Value *value);
void knownArgumentError(const Token *tok, const Token *ftok, const ValueFlow::Value *value, const std::string &varexpr);
void comparePointersError(const Token *tok, const ValueFlow::Value *v1, const ValueFlow::Value *v2);
void checkModuloOfOneError(const Token *tok);
@ -342,7 +342,7 @@ private:
c.shadowError(nullptr, nullptr, "variable");
c.shadowError(nullptr, nullptr, "function");
c.shadowError(nullptr, nullptr, "argument");
c.knownArgumentError(nullptr, nullptr, nullptr);
c.knownArgumentError(nullptr, nullptr, nullptr, "x");
c.comparePointersError(nullptr, nullptr, nullptr);
c.redundantAssignmentError(nullptr, nullptr, "var", false);
c.redundantInitializationError(nullptr, nullptr, "var", false);
@ -411,7 +411,8 @@ private:
"- function declaration and definition argument order different.\n"
"- shadow variable.\n"
"- variable can be declared const.\n"
"- calculating modulo of one.\n";
"- calculating modulo of one.\n"
"- known function argument, suspicious calculation.";
}
};
/// @}

15
test/testother.cpp
View File

@ -8745,13 +8745,13 @@ private:
"void f(int x) {\n"
" g((x & 0x01) >> 7);\n"
"}\n");
ASSERT_EQUALS("[test.cpp:3]: (style) Argument '(x&0x01)>>7' to function g is always 0\n", errout.str());
ASSERT_EQUALS("[test.cpp:3]: (style) Argument '(x&0x01)>>7' to function g is always 0. It does not matter what value 'x' has.\n", errout.str());
check("void g(int);\n"
"void f(int x) {\n"
" g((int)((x & 0x01) >> 7));\n"
"}\n");
ASSERT_EQUALS("[test.cpp:3]: (style) Argument '(int)((x&0x01)>>7)' to function g is always 0\n", errout.str());
ASSERT_EQUALS("[test.cpp:3]: (style) Argument '(int)((x&0x01)>>7)' to function g is always 0. It does not matter what value 'x' has.\n", errout.str());
check("void g(int);\n"
"void f(int x) {\n"
@ -8842,6 +8842,17 @@ private:
" std::cout << std::setw(heading.length());\n"
"}");
ASSERT_EQUALS("", errout.str());
// #9909 - struct member with known value
check("struct LongStack {\n"
" int maxsize;\n"
"};\n"
"\n"
"void growLongStack(LongStack* self) {\n"
" self->maxsize = 32;\n"
" dostuff(self->maxsize * sizeof(intptr_t));\n"
"}");
ASSERT_EQUALS("", errout.str());
}
void checkComparePointers() {