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Fixed #7663 (False positive: uninitialized variable (multi variables in inner scopes))

This commit is contained in:
Daniel Marjamäki 2017-09-07 23:08:55 +02:00
parent 120d0f86d0
commit 57004ed533
3 changed files with 30 additions and 17 deletions
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28
lib/checkuninitvar.cpp
View File

@ -124,12 +124,14 @@ void CheckUninitVar::checkScope(const Scope* scope, const std::set<std::string>
if (i->isArray()) {
Alloc alloc = ARRAY;
checkScopeForVariable(tok, *i, nullptr, nullptr, &alloc, emptyString);
std::map<unsigned int, VariableValue> variableValue;
checkScopeForVariable(tok, *i, nullptr, nullptr, &alloc, emptyString, variableValue);
continue;
}
if (stdtype || i->isPointer()) {
Alloc alloc = NO_ALLOC;
checkScopeForVariable(tok, *i, nullptr, nullptr, &alloc, emptyString);
std::map<unsigned int, VariableValue> variableValue;
checkScopeForVariable(tok, *i, nullptr, nullptr, &alloc, emptyString, variableValue);
}
if (i->type())
checkStruct(tok, *i);
@ -147,7 +149,8 @@ void CheckUninitVar::checkScope(const Scope* scope, const std::set<std::string>
checkStruct(tok, *arg);
else if (arg->typeStartToken()->isStandardType() || arg->typeStartToken()->isEnumType()) {
Alloc alloc = NO_ALLOC;
checkScopeForVariable(tok->next(), *arg, nullptr, nullptr, &alloc, emptyString);
std::map<unsigned int, VariableValue> variableValue;
checkScopeForVariable(tok->next(), *arg, nullptr, nullptr, &alloc, emptyString, variableValue);
}
}
}
@ -188,18 +191,14 @@ void CheckUninitVar::checkStruct(const Token *tok, const Variable &structvar)
const Token *tok2 = tok;
if (tok->str() == "}")
tok2 = tok2->next();
checkScopeForVariable(tok2, structvar, nullptr, nullptr, &alloc, var.name());
std::map<unsigned int, VariableValue> variableValue;
checkScopeForVariable(tok2, structvar, nullptr, nullptr, &alloc, var.name(), variableValue);
}
}
}
}
}
struct VariableValue {
explicit VariableValue(MathLib::bigint val = 0) : value(val), notEqual(false) {}
MathLib::bigint value;
bool notEqual;
};
static VariableValue operator!(VariableValue v)
{
v.notEqual = !v.notEqual;
@ -319,7 +318,7 @@ static bool isVariableUsed(const Token *tok, const Variable& var)
return !parent2 || parent2->isConstOp() || (parent2->str() == "=" && parent2->astOperand2() == parent);
}
bool CheckUninitVar::checkScopeForVariable(const Token *tok, const Variable& var, bool * const possibleInit, bool * const noreturn, Alloc* 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, std::map<unsigned int, VariableValue> variableValue)
{
const bool suppressErrors(possibleInit && *possibleInit);
const bool printDebug = _settings->debugwarnings;
@ -332,9 +331,6 @@ bool CheckUninitVar::checkScopeForVariable(const Token *tok, const Variable& var
if (var.declarationId() == 0U)
return true;
// variable values
std::map<unsigned int, VariableValue> variableValue;
for (; tok; tok = tok->next()) {
// End of scope..
if (tok->str() == "}") {
@ -353,7 +349,7 @@ bool CheckUninitVar::checkScopeForVariable(const Token *tok, const Variable& var
// Unconditional inner scope or try..
if (tok->str() == "{" && Token::Match(tok->previous(), ",|;|{|}|try")) {
if (checkScopeForVariable(tok->next(), var, possibleInit, noreturn, alloc, membervar))
if (checkScopeForVariable(tok->next(), var, possibleInit, noreturn, alloc, membervar, variableValue))
return true;
tok = tok->link();
continue;
@ -418,7 +414,7 @@ bool CheckUninitVar::checkScopeForVariable(const Token *tok, const Variable& var
if (tok->str() == "{") {
bool possibleInitIf((!alwaysTrue && number_of_if > 0) || suppressErrors);
bool noreturnIf = false;
const bool initif = !alwaysFalse && checkScopeForVariable(tok->next(), var, &possibleInitIf, &noreturnIf, alloc, membervar);
const bool initif = !alwaysFalse && checkScopeForVariable(tok->next(), var, &possibleInitIf, &noreturnIf, alloc, membervar, variableValue);
// bail out for such code:
// if (a) x=0; // conditional initialization
@ -468,7 +464,7 @@ bool CheckUninitVar::checkScopeForVariable(const Token *tok, const Variable& var
bool possibleInitElse((!alwaysFalse && number_of_if > 0) || suppressErrors);
bool noreturnElse = false;
const bool initelse = !alwaysTrue && checkScopeForVariable(tok->next(), var, &possibleInitElse, &noreturnElse, alloc, membervar);
const bool initelse = !alwaysTrue && checkScopeForVariable(tok->next(), var, &possibleInitElse, &noreturnElse, alloc, membervar, variableValue);
std::map<unsigned int, VariableValue> varValueElse;
if (!alwaysTrue && !initelse && !noreturnElse) {

9
lib/checkuninitvar.h
View File

@ -35,6 +35,13 @@ class Token;
class Tokenizer;
class Variable;
struct VariableValue {
explicit VariableValue(MathLib::bigint val = 0) : value(val), notEqual(false) {}
MathLib::bigint value;
bool notEqual;
};
/// @addtogroup Checks
/// @{
@ -65,7 +72,7 @@ public:
void checkScope(const Scope* scope, const std::set<std::string> &arrayTypeDefs);
void checkStruct(const Token *tok, const Variable &structvar);
enum Alloc { NO_ALLOC, NO_CTOR_CALL, CTOR_CALL, ARRAY };
bool checkScopeForVariable(const Token *tok, const Variable& var, bool* const possibleInit, bool* const noreturn, Alloc* const alloc, const std::string &membervar);
bool checkScopeForVariable(const Token *tok, const Variable& var, bool* const possibleInit, bool* const noreturn, Alloc* const alloc, const std::string &membervar, std::map<unsigned int, VariableValue> variableValue);
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, unsigned int number_of_if, const std::string &membervar);

10
test/testuninitvar.cpp
View File

@ -2489,6 +2489,16 @@ private:
"}");
ASSERT_EQUALS("", errout.str());
checkUninitVar("void f(int a) {\n"
" int x;\n"
" if (a) x=123;\n"
" if (!a) {\n"
" if (!a) {}\n"
" else if (x) {}\n"
" }\n"
"}");
ASSERT_EQUALS("", errout.str());
// asm
checkUninitVar("void f() {\n"
" int x;\n"