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Fixed #8246 (ValueFlow: known value, function pointer argument)

This commit is contained in:
Daniel Marjamäki 2017-11-17 23:04:54 +01:00
parent 5cfa13c31c
commit 9191e6f112
2 changed files with 62 additions and 24 deletions
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65
lib/valueflow.cpp
View File

@ -108,6 +108,34 @@ static void bailoutInternal(TokenList *tokenlist, ErrorLogger *errorLogger, cons
#define bailout(tokenlist, errorLogger, tok, what) bailoutInternal(tokenlist, errorLogger, tok, what, __FILE__, __LINE__, "(valueFlow)")
#endif
static void changeKnownToPossible(std::list<ValueFlow::Value> &values)
{
std::list<ValueFlow::Value>::iterator it;
for (it = values.begin(); it != values.end(); ++it)
it->changeKnownToPossible();
}
static bool mightBeNonConstPointerFunctionArg(const Token *tok)
{
// TODO: check if argument might be non-const pointer
const Token *parent = tok->astParent();
while (parent && parent->str() == ",")
parent = parent->astParent();
return (parent && Token::Match(parent->previous(), "%name% ("));
}
static const Token *findVariableInAST(const Token *tok, unsigned int varid)
{
if (!tok)
return nullptr;
if (tok->varId() == varid)
return tok;
const Token *ret1 = findVariableInAST(tok->astOperand1(), varid);
if (ret1)
return ret1;
return findVariableInAST(tok->astOperand2(), varid);
}
/**
* Is condition always false when variable has given value?
* \param condition top ast token in condition
@ -1465,9 +1493,7 @@ static bool valueFlowForward(Token * const startToken,
Token::simpleMatch(tok2->link()->previous(), "else {") &&
!isReturnScope(tok2->link()->tokAt(-2)) &&
isVariableChanged(tok2->link(), tok2, varid, var->isGlobal(), settings)) {
std::list<ValueFlow::Value>::iterator it;
for (it = values.begin(); it != values.end(); ++it)
it->changeKnownToPossible();
changeKnownToPossible(values);
}
}
@ -1482,8 +1508,7 @@ static bool valueFlowForward(Token * const startToken,
}
if (Token::Match(tok2, "[;{}] %name% :") || tok2->str() == "case") {
for (std::list<ValueFlow::Value>::iterator it = values.begin(); it != values.end(); ++it)
it->changeKnownToPossible();
changeKnownToPossible(values);
tok2 = tok2->tokAt(2);
continue;
}
@ -1597,10 +1622,7 @@ static bool valueFlowForward(Token * const startToken,
if (!condAlwaysFalse && isVariableChanged(startToken1, startToken1->link(), varid, var->isGlobal(), settings)) {
removeValues(values, truevalues);
std::list<ValueFlow::Value>::iterator it;
for (it = values.begin(); it != values.end(); ++it)
it->changeKnownToPossible();
changeKnownToPossible(values);
}
// goto '}'
@ -1628,10 +1650,7 @@ static bool valueFlowForward(Token * const startToken,
if (!condAlwaysTrue && isVariableChanged(startTokenElse, startTokenElse->link(), varid, var->isGlobal(), settings)) {
removeValues(values, falsevalues);
std::list<ValueFlow::Value>::iterator it;
for (it = values.begin(); it != values.end(); ++it)
it->changeKnownToPossible();
changeKnownToPossible(values);
}
// goto '}'
@ -1811,9 +1830,7 @@ static bool valueFlowForward(Token * const startToken,
if (tok2 == endToken)
break;
--indentlevel;
for (std::list<ValueFlow::Value>::iterator it = values.begin(); it != values.end(); ++it) {
it->changeKnownToPossible();
}
changeKnownToPossible(values);
continue;
}
}
@ -1841,6 +1858,8 @@ static bool valueFlowForward(Token * const startToken,
std::list<ValueFlow::Value>::const_iterator it;
for (it = values.begin(); it != values.end(); ++it)
valueFlowAST(const_cast<Token*>(expr), varid, *it, settings);
if ((expr->valueType() && expr->valueType()->pointer) && mightBeNonConstPointerFunctionArg(tok2) && findVariableInAST(expr,varid))
changeKnownToPossible(values);
} else {
std::list<ValueFlow::Value>::const_iterator it;
for (it = values.begin(); it != values.end(); ++it) {
@ -1852,6 +1871,9 @@ static bool valueFlowForward(Token * const startToken,
else
valueFlowAST(const_cast<Token*>(op2), varid, *it, settings);
}
if (mightBeNonConstPointerFunctionArg(tok2) && findVariableInAST(op2,varid))
changeKnownToPossible(values);
}
// Skip conditional expressions..
@ -2245,11 +2267,8 @@ static void valueFlowAfterAssign(TokenList *tokenlist, SymbolDatabase* symboldat
}
// Static variable initialisation?
if (var->isStatic() && var->nameToken() == tok->astOperand1()) {
for (std::list<ValueFlow::Value>::iterator it = values.begin(); it != values.end(); ++it) {
it->changeKnownToPossible();
}
}
if (var->isStatic() && var->nameToken() == tok->astOperand1())
changeKnownToPossible(values);
// Skip RHS
const Token * nextExpression = nextAfterAstRightmostLeaf(tok);
@ -3057,9 +3076,7 @@ static void valueFlowSubFunction(TokenList *tokenlist, ErrorLogger *errorLogger,
}
// passed values are not "known"..
for (std::list<ValueFlow::Value>::iterator it = argvalues.begin(); it != argvalues.end(); ++it) {
it->changeKnownToPossible();
}
changeKnownToPossible(argvalues);
valueFlowInjectParameter(tokenlist, errorLogger, settings, argvar, calledFunctionScope, argvalues);
}

21
test/testvalueflow.cpp
View File

@ -2390,6 +2390,27 @@ private:
"}";
ASSERT(isNotKnownValues(code, "+"));
code = "void f() {\n"
" int x = 0;\n"
" dostuff(&x);\n"
" if (x < 0) {}\n"
"}\n";
ASSERT(isNotKnownValues(code, "<"));
code = "void f() {\n"
" int x = 0;\n"
" dostuff(0 ? ptr : &x);\n"
" if (x < 0) {}\n"
"}\n";
ASSERT(isNotKnownValues(code, "<"));
code = "void f() {\n"
" int x = 0;\n"
" dostuff(unknown ? ptr : &x);\n"
" if (x < 0) {}\n"
"}\n";
ASSERT(isNotKnownValues(code, "<"));
code = "void f() {\n"
" int x = 0;\n"
" fred.dostuff(x);\n"