walkero
/
cppcheck
1
0
Fork 0
Code Issues Pull Requests Projects Releases 1 Wiki Activity

Fixed false positives #6450 and #6451

This commit is contained in:
PKEuS 2015-01-23 19:38:39 +01:00
parent da35a74589
commit ee046af20c
3 changed files with 85 additions and 45 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

77
lib/checkuninitvar.cpp
View File

@ -1069,7 +1069,7 @@ void CheckUninitVar::checkScope(const Scope* scope)
continue;
if (Token::Match(i->nameToken(), "%var% =")) { // Variable is initialized, but Rhs might be not
checkRhs(i->nameToken(), *i, false, "");
checkRhs(i->nameToken(), *i, NO_ALLOC, "");
continue;
}
@ -1086,7 +1086,7 @@ void CheckUninitVar::checkScope(const Scope* scope)
continue;
if (stdtype || i->isPointer()) {
bool alloc = false;
Alloc alloc = NO_ALLOC;
checkScopeForVariable(tok, *i, nullptr, nullptr, &alloc, "");
}
if (i->type())
@ -1104,7 +1104,7 @@ void CheckUninitVar::checkScope(const Scope* scope)
if (arg->typeStartToken()->str() == "struct")
checkStruct(tok, *arg);
else if (arg->typeStartToken()->isStandardType()) {
bool alloc = false;
Alloc alloc = NO_ALLOC;
checkScopeForVariable(tok->next(), *arg, nullptr, nullptr, &alloc, "");
}
}
@ -1119,11 +1119,10 @@ void CheckUninitVar::checkStruct(const Token *tok, const Variable &structvar)
const Token *typeToken = structvar.typeStartToken();
if (typeToken->str() == "struct")
typeToken = typeToken->next();
const std::string structname(typeToken->str());
const SymbolDatabase * symbolDatabase = _tokenizer->getSymbolDatabase();
for (std::size_t j = 0U; j < symbolDatabase->classAndStructScopes.size(); ++j) {
const Scope *scope2 = symbolDatabase->classAndStructScopes[j];
if (scope2->className == structname && scope2->numConstructors == 0U) {
if (scope2->className == typeToken->str() && scope2->numConstructors == 0U) {
for (std::list<Variable>::const_iterator it = scope2->varlist.begin(); it != scope2->varlist.end(); ++it) {
const Variable &var = *it;
@ -1145,7 +1144,7 @@ void CheckUninitVar::checkStruct(const Token *tok, const Variable &structvar)
}
if (!innerunion) {
bool alloc = false;
Alloc alloc = NO_ALLOC;
const Token *tok2 = tok;
if (tok->str() == "}")
tok2 = tok2->next();
@ -1197,7 +1196,7 @@ static void conditionAlwaysTrueOrFalse(const Token *tok, const std::map<unsigned
}
}
bool CheckUninitVar::checkScopeForVariable(const Token *tok, const Variable& var, bool * const possibleInit, bool * const noreturn, bool * const alloc, const std::string &membervar)
bool CheckUninitVar::checkScopeForVariable(const Token *tok, const Variable& var, bool * const possibleInit, bool * const noreturn, Alloc* const alloc, const std::string &membervar)
{
const bool suppressErrors(possibleInit && *possibleInit);
@ -1249,7 +1248,7 @@ bool CheckUninitVar::checkScopeForVariable(const Token *tok, const Variable& var
conditionAlwaysTrueOrFalse(tok, variableValue, &alwaysTrue, &alwaysFalse);
// initialization / usage in condition..
if (!alwaysTrue && checkIfForWhileHead(tok->next(), var, suppressErrors, bool(number_of_if == 0), alloc && *alloc, membervar))
if (!alwaysTrue && checkIfForWhileHead(tok->next(), var, suppressErrors, bool(number_of_if == 0), *alloc, membervar))
return true;
// checking if a not-zero variable is zero => bail out
@ -1376,14 +1375,14 @@ bool CheckUninitVar::checkScopeForVariable(const Token *tok, const Variable& var
const bool forwhile = Token::Match(tok, "for|while (");
// is variable initialized in for-head (don't report errors yet)?
if (forwhile && checkIfForWhileHead(tok->next(), var, true, false, alloc && *alloc, membervar))
if (forwhile && checkIfForWhileHead(tok->next(), var, true, false, *alloc, membervar))
return true;
// goto the {
const Token *tok2 = forwhile ? tok->next()->link()->next() : tok->next();
if (tok2 && tok2->str() == "{") {
bool init = checkLoopBody(tok2, var, alloc && *alloc, membervar, (number_of_if > 0) || suppressErrors);
bool init = checkLoopBody(tok2, var, *alloc, membervar, (number_of_if > 0) || suppressErrors);
// variable is initialized in the loop..
if (init)
@ -1393,7 +1392,7 @@ bool CheckUninitVar::checkScopeForVariable(const Token *tok, const Variable& var
bool initcond = false;
if (!suppressErrors) {
const Token *startCond = forwhile ? tok->next() : tok->next()->link()->tokAt(2);
initcond = checkIfForWhileHead(startCond, var, false, bool(number_of_if == 0), alloc && *alloc, membervar);
initcond = checkIfForWhileHead(startCond, var, false, bool(number_of_if == 0), *alloc, membervar);
}
// goto "}"
@ -1461,8 +1460,8 @@ bool CheckUninitVar::checkScopeForVariable(const Token *tok, const Variable& var
}
// Use variable
else if (!suppressErrors && isVariableUsage(tok, var.isPointer(), alloc && *alloc)) {
if (alloc && *alloc)
else if (!suppressErrors && isVariableUsage(tok, var.isPointer(), *alloc)) {
if (*alloc != NO_ALLOC)
uninitdataError(tok, tok->str());
else
uninitvarError(tok, tok->str());
@ -1496,14 +1495,14 @@ bool CheckUninitVar::checkScopeForVariable(const Token *tok, const Variable& var
Token::simpleMatch(tok->linkAt(3), ") ;") &&
_settings->library.returnuninitdata.count(tok->strAt(2)) > 0U) {
if (alloc)
*alloc = true;
*alloc = NO_CTOR_CALL;
continue;
}
if (var.isPointer() && (var.typeStartToken()->isStandardType() || (var.type() && var.type()->needInitialization == Type::True)) && Token::simpleMatch(tok->next(), "= new")) {
if (alloc) {
*alloc = true;
*alloc = CTOR_CALL;
if (var.typeScope() && var.typeScope()->numConstructors > 0)
return false;
return true;
}
continue;
}
@ -1511,11 +1510,11 @@ bool CheckUninitVar::checkScopeForVariable(const Token *tok, const Variable& var
if (!membervar.empty()) {
if (isMemberVariableAssignment(tok, membervar)) {
checkRhs(tok, var, alloc && *alloc, membervar);
checkRhs(tok, var, *alloc, membervar);
return true;
}
if (isMemberVariableUsage(tok, var.isPointer(), alloc && *alloc, membervar))
if (isMemberVariableUsage(tok, var.isPointer(), *alloc, membervar))
uninitStructMemberError(tok, tok->str() + "." + membervar);
else if (Token::Match(tok->previous(), "[(,] %var% [,)]"))
@ -1523,8 +1522,8 @@ bool CheckUninitVar::checkScopeForVariable(const Token *tok, const Variable& var
} else {
// Use variable
if (!suppressErrors && isVariableUsage(tok, var.isPointer(), alloc && *alloc)) {
if (alloc && *alloc)
if (!suppressErrors && isVariableUsage(tok, var.isPointer(), *alloc)) {
if (*alloc != NO_ALLOC)
uninitdataError(tok, tok->str());
else
uninitvarError(tok, tok->str());
@ -1532,7 +1531,7 @@ bool CheckUninitVar::checkScopeForVariable(const Token *tok, const Variable& var
else {
if (tok->strAt(1) == "=")
checkRhs(tok, var, alloc && *alloc, "");
checkRhs(tok, var, *alloc, "");
// assume that variable is assigned
return true;
@ -1544,7 +1543,7 @@ bool CheckUninitVar::checkScopeForVariable(const Token *tok, const Variable& var
return false;
}
bool CheckUninitVar::checkIfForWhileHead(const Token *startparentheses, const Variable& var, bool suppressErrors, bool isuninit, bool alloc, const std::string &membervar)
bool CheckUninitVar::checkIfForWhileHead(const Token *startparentheses, const Variable& var, bool suppressErrors, bool isuninit, Alloc alloc, const std::string &membervar)
{
const Token * const endpar = startparentheses->link();
if (Token::Match(startparentheses, "( ! %var% %oror%") && startparentheses->tokAt(2)->getValue(0))
@ -1578,7 +1577,7 @@ bool CheckUninitVar::checkIfForWhileHead(const Token *startparentheses, const Va
return false;
}
bool CheckUninitVar::checkLoopBody(const Token *tok, const Variable& var, const bool alloc, const std::string &membervar, const bool suppressErrors)
bool CheckUninitVar::checkLoopBody(const Token *tok, const Variable& var, const Alloc alloc, const std::string &membervar, const bool suppressErrors)
{
const Token *usetok = nullptr;
@ -1660,7 +1659,7 @@ bool CheckUninitVar::checkLoopBody(const Token *tok, const Variable& var, const
return false;
}
void CheckUninitVar::checkRhs(const Token *tok, const Variable &var, bool alloc, const std::string &membervar)
void CheckUninitVar::checkRhs(const Token *tok, const Variable &var, Alloc alloc, const std::string &membervar)
{
bool rhs = false;
unsigned int indent = 0;
@ -1686,9 +1685,9 @@ void CheckUninitVar::checkRhs(const Token *tok, const Variable &var, bool alloc,
}
}
bool CheckUninitVar::isVariableUsage(const Token *vartok, bool pointer, bool alloc) const
bool CheckUninitVar::isVariableUsage(const Token *vartok, bool pointer, Alloc alloc) const
{
if (!alloc && ((Token::Match(vartok->previous(), "return|delete") && vartok->strAt(1) != "=") || (vartok->strAt(-1) == "]" && vartok->linkAt(-1)->strAt(-1) == "delete")))
if (alloc == NO_ALLOC && ((Token::Match(vartok->previous(), "return|delete") && vartok->strAt(1) != "=") || (vartok->strAt(-1) == "]" && vartok->linkAt(-1)->strAt(-1) == "delete")))
return true;
// Passing variable to typeof/__alignof__
@ -1707,7 +1706,7 @@ bool CheckUninitVar::isVariableUsage(const Token *vartok, bool pointer, bool all
tok2 = tok2->tokAt(2);
if (Token::Match(tok2, "[,)]"))
return false;
} else if (pointer && Token::Match(vartok, "%var% . %var% (")) {
} else if (pointer && alloc != CTOR_CALL && Token::Match(vartok, "%var% . %var% (")) {
return true;
}
@ -1718,7 +1717,7 @@ bool CheckUninitVar::isVariableUsage(const Token *vartok, bool pointer, bool all
assignment = true;
break;
}
if (alloc && parent->str() == "(") {
if (alloc != NO_ALLOC && parent->str() == "(") {
if (_settings->library.functionpure.find(parent->strAt(-1)) == _settings->library.functionpure.end()) {
assignment = true;
break;
@ -1756,13 +1755,13 @@ bool CheckUninitVar::isVariableUsage(const Token *vartok, bool pointer, bool all
return true;
if (!address && Token::Match(argStart, "struct| %type% %var% [,)]"))
return true;
if (pointer && !address && !alloc && Token::Match(argStart, "struct| %type% * %var% [,)]"))
if (pointer && !address && alloc == NO_ALLOC && Token::Match(argStart, "struct| %type% * %var% [,)]"))
return true;
while (argStart->previous() && argStart->previous()->isName())
argStart = argStart->previous();
if (Token::Match(argStart, "const %type% & %var% [,)]"))
return true;
if ((pointer || address) && !alloc && Token::Match(argStart, "const struct| %type% * %var% [,)]"))
if ((pointer || address) && alloc == NO_ALLOC && Token::Match(argStart, "const struct| %type% * %var% [,)]"))
return true;
if ((pointer || address) && Token::Match(argStart, "const %type% %var% [") && Token::Match(argStart->linkAt(3), "] [,)]"))
return true;
@ -1770,11 +1769,11 @@ bool CheckUninitVar::isVariableUsage(const Token *vartok, bool pointer, bool all
} else if (Token::Match(start->previous(), "if|while|for")) {
// control-flow statement reading the variable "by value"
return !alloc;
return alloc == NO_ALLOC;
} else {
bool isnullbad = _settings->library.isnullargbad(start->previous(), argumentNumber + 1);
bool isuninitbad = _settings->library.isuninitargbad(start->previous(), argumentNumber + 1);
if (alloc)
if (alloc != NO_ALLOC)
return isnullbad && isuninitbad;
return isuninitbad && (!address || isnullbad);
}
@ -1809,17 +1808,17 @@ bool CheckUninitVar::isVariableUsage(const Token *vartok, bool pointer, bool all
return false;
if (vartok->previous()->str() != "&" || !Token::Match(vartok->tokAt(-2), "[(,=?:]")) {
if (alloc && vartok->previous()->str() == "*") {
if (alloc != NO_ALLOC && vartok->previous()->str() == "*") {
const Token *parent = vartok->previous()->astParent();
if (parent && parent->str() == "=" && parent->astOperand1() == vartok->previous())
return false;
return true;
}
return !alloc;
return alloc == NO_ALLOC;
}
}
if (!alloc && Token::Match(vartok->previous(), "= %var% ;|%cop%"))
if (alloc == NO_ALLOC && Token::Match(vartok->previous(), "= %var% ;|%cop%"))
return true;
if (Token::Match(vartok->previous(), "? %var%")) {
@ -1842,7 +1841,7 @@ bool CheckUninitVar::isVariableUsage(const Token *vartok, bool pointer, bool all
bool unknown = false;
if (pointer && CheckNullPointer::isPointerDeRef(vartok, unknown)) {
// pointer is allocated - dereferencing it is ok.
if (alloc)
if (alloc != NO_ALLOC)
return false;
// function parameter?
@ -1869,7 +1868,7 @@ bool CheckUninitVar::isVariableUsage(const Token *vartok, bool pointer, bool all
return (var && var->typeStartToken()->isStandardType());
}
if (!alloc && vartok->next() && vartok->next()->isOp() && !vartok->next()->isAssignmentOp())
if (alloc == NO_ALLOC && vartok->next() && vartok->next()->isOp() && !vartok->next()->isAssignmentOp())
return true;
if (vartok->strAt(1) == "]")
@ -1927,7 +1926,7 @@ bool CheckUninitVar::isMemberVariableAssignment(const Token *tok, const std::str
return false;
}
bool CheckUninitVar::isMemberVariableUsage(const Token *tok, bool isPointer, bool alloc, const std::string &membervar) const
bool CheckUninitVar::isMemberVariableUsage(const Token *tok, bool isPointer, Alloc alloc, const std::string &membervar) const
{
if (isMemberVariableAssignment(tok, membervar))
return false;
@ -1993,7 +1992,7 @@ void CheckUninitVar::deadPointer()
for (const Token* tok = scope->classStart; tok != scope->classEnd; tok = tok->next()) {
if (tok->variable() &&
tok->variable()->isPointer() &&
isVariableUsage(tok, true, false)) {
isVariableUsage(tok, true, NO_ALLOC)) {
const Token *alias = tok->getValueTokenDeadPointer();
if (alias) {
deadPointerError(tok,alias);

13
lib/checkuninitvar.h
View File

@ -57,13 +57,14 @@ public:
void check();
void checkScope(const Scope* scope);
void checkStruct(const Token *tok, const Variable &structvar);
bool checkScopeForVariable(const Token *tok, const Variable& var, bool * const possibleInit, bool * const noreturn, bool * const alloc, const std::string &membervar);
bool checkIfForWhileHead(const Token *startparentheses, const Variable& var, bool suppressErrors, bool isuninit, bool alloc, const std::string &membervar);
bool checkLoopBody(const Token *tok, const Variable& var, const bool alloc, const std::string &membervar, const bool suppressErrors);
void checkRhs(const Token *tok, const Variable &var, bool alloc, const std::string &membervar);
bool isVariableUsage(const Token *vartok, bool ispointer, bool alloc) const;
enum Alloc { NO_ALLOC, NO_CTOR_CALL, CTOR_CALL };
bool checkScopeForVariable(const Token *tok, const Variable& var, bool* const possibleInit, bool* const noreturn, Alloc* const alloc, const std::string &membervar);
bool checkIfForWhileHead(const Token *startparentheses, const Variable& var, bool suppressErrors, bool isuninit, Alloc alloc, const std::string &membervar);
bool checkLoopBody(const Token *tok, const Variable& var, const Alloc alloc, const std::string &membervar, const bool suppressErrors);
void checkRhs(const Token *tok, const Variable &var, Alloc alloc, const std::string &membervar);
bool isVariableUsage(const Token *vartok, bool ispointer, Alloc alloc) const;
static bool isMemberVariableAssignment(const Token *tok, const std::string &membervar);
bool isMemberVariableUsage(const Token *tok, bool isPointer, bool alloc, const std::string &membervar) const;
bool isMemberVariableUsage(const Token *tok, bool isPointer, Alloc alloc, const std::string &membervar) const;
/** ValueFlow-based checking for dead pointer usage */
void deadPointer();

40
test/testuninitvar.cpp
View File

@ -1592,6 +1592,46 @@ private:
" memcpy(body, buf, 10);\n"
"}");
ASSERT_EQUALS("", errout.str());
// #6451 - allocation in subscope
checkUninitVarB("struct StgStrm {\n"
" StgIo& rIo;\n"
" StgStrm(StgIo&);\n"
" virtual sal_Int32 Write();\n"
"};\n"
"void Tmp2Strm() {\n"
" StgStrm* pNewStrm;\n"
" if (someflag)\n"
" pNewStrm = new StgStrm(rIo);\n"
" else\n"
" pNewStrm = new StgStrm(rIo);\n"
" pNewStrm->Write();\n"
"}");
ASSERT_EQUALS("", errout.str());
checkUninitVarB("struct StgStrm {\n"
" StgIo& rIo;\n"
" StgStrm(StgIo&);\n"
" virtual sal_Int32 Write();\n"
"};\n"
"void Tmp2Strm() {\n"
" StgStrm* pNewStrm;\n"
" if (someflag)\n"
" pNewStrm = new StgStrm(rIo);\n"
" pNewStrm->Write();\n"
"}");
ASSERT_EQUALS("[test.cpp:10]: (error) Uninitialized variable: pNewStrm\n", errout.str());
// #6450 - calling a member function is allowed if memory was allocated by new
checkUninitVarB("struct EMFPFont {\n"
" bool family;\n"
" void Initialize();\n"
"};\n"
"void processObjectRecord() {\n"
" EMFPFont *font = new EMFPFont();\n"
" font->Initialize();\n"
"}");
ASSERT_EQUALS("", errout.str());
}
// class / struct..