Fix issue 6010: Uninitialized inner struct (#2098)

* Fix issue 6010: Uninitialized inner struct

* Show to root variable that is unitialized

* Warn on pointer dereferences
This commit is contained in:
Paul Fultz II 2019-08-22 23:23:21 -05:00 committed by Daniel Marjamäki
parent 5bbc7ee6b6
commit c0a8d628b9
5 changed files with 59 additions and 4 deletions

View File

@ -52,6 +52,26 @@ void visitAstNodes(const Token *ast, std::function<ChildrenToVisit(const Token *
}
}
static void astFlattenRecursive(const Token *tok, std::vector<const Token *> *result, const char* op, nonneg int depth = 0)
{
++depth;
if (!tok || depth >= 100)
return;
if (tok->str() == op) {
astFlattenRecursive(tok->astOperand1(), result, op, depth);
astFlattenRecursive(tok->astOperand2(), result, op, depth);
} else {
result->push_back(tok);
}
}
std::vector<const Token*> astFlatten(const Token* tok, const char* op)
{
std::vector<const Token*> result;
astFlattenRecursive(tok, &result, op);
return result;
}
static bool astIsCharWithSign(const Token *tok, ValueType::Sign sign)
{

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@ -48,6 +48,8 @@ enum class ChildrenToVisit {
*/
void visitAstNodes(const Token *ast, std::function<ChildrenToVisit(const Token *)> visitor);
std::vector<const Token*> astFlatten(const Token* tok, const char* op);
/** Is expression a 'signed char' if no promotion is used */
bool astIsSignedChar(const Token *tok);
/** Is expression a 'char' if no promotion is used? */

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@ -1284,6 +1284,18 @@ void CheckUninitVar::uninitStructMemberError(const Token *tok, const std::string
"$symbol:" + membername + "\nUninitialized struct member: $symbol", CWE908, false);
}
static bool isLeafDot(const Token* tok)
{
if (!tok)
return false;
const Token * parent = tok->astParent();
if (!Token::simpleMatch(parent, "."))
return false;
if (parent->astOperand2() == tok)
return true;
return isLeafDot(parent);
}
void CheckUninitVar::valueFlowUninit()
{
const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
@ -1299,8 +1311,6 @@ void CheckUninitVar::valueFlowUninit()
}
if (!tok->variable())
continue;
if (Token::Match(tok->astParent(), ". %var%") && tok->astParent()->astOperand1() == tok)
continue;
auto v = std::find_if(tok->values().begin(), tok->values().end(), std::mem_fn(&ValueFlow::Value::isUninitValue));
if (v == tok->values().end())
continue;
@ -1311,11 +1321,19 @@ void CheckUninitVar::valueFlowUninit()
if (v->indirect > 1 || v->indirect < 0)
continue;
bool unknown;
if (v->indirect == 1 && !CheckNullPointer::isPointerDeRef(tok, unknown, mSettings))
const bool deref = CheckNullPointer::isPointerDeRef(tok, unknown, mSettings);
if (v->indirect == 1 && !deref)
continue;
if (Token::Match(tok->astParent(), ". %var%") && !(isLeafDot(tok) || deref))
continue;
if (!Token::Match(tok->astParent(), ". %name% (") && isVariableChanged(tok, mSettings, mTokenizer->isCPP()))
continue;
uninitvarError(tok, tok->str(), v->errorPath);
const Token * nextTok = tok;
while(Token::simpleMatch(nextTok->astParent(), "."))
nextTok = nextTok->astParent();
nextTok = nextAfterAstRightmostLeaf(nextTok);
tok = nextTok ? nextTok : tok;
}
}
}

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@ -461,9 +461,13 @@ static void setTokenValue(Token* tok, const ValueFlow::Value &value, const Setti
pvalue.indirect++;
setTokenValue(parent, pvalue, settings);
} else if (Token::Match(parent, ". %var%") && parent->astOperand1() == tok) {
if (parent->originalName() == "->")
if (parent->originalName() == "->" && pvalue.indirect > 0)
pvalue.indirect--;
setTokenValue(parent->astOperand2(), pvalue, settings);
} else if (Token::Match(parent->astParent(), ". %var%") && parent->astParent()->astOperand1() == parent) {
if (parent->astParent()->originalName() == "->" && pvalue.indirect > 0)
pvalue.indirect--;
setTokenValue(parent->astParent()->astOperand2(), pvalue, settings);
} else if (parent->isUnaryOp("*") && pvalue.indirect > 0) {
pvalue.indirect--;
setTokenValue(parent, pvalue, settings);

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@ -4004,6 +4004,17 @@ private:
"}\n");
ASSERT_EQUALS("[test.cpp:7]: (error) Uninitialized variable: flags\n", errout.str());
valueFlowUninit("struct pc_data {\n"
" struct {\n"
" char * strefa;\n"
" } wampiryzm;\n"
"};\n"
"void f() {\n"
" struct pc_data *pcdata;\n"
" if ( *pcdata->wampiryzm.strefa == '\\0' ) { }\n"
"}\n");
ASSERT_EQUALS("[test.cpp:8]: (error) Uninitialized variable: pcdata\n", errout.str());
valueFlowUninit("void f(bool * x) {\n"
" *x = false;\n"
"}\n"