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Fixed #9251 (False positive: unininitialized variable (multi variables))

This commit is contained in:
Daniel Marjamäki 2019-08-03 21:12:14 +02:00
parent 24431419f4
commit ce53931d00
2 changed files with 24 additions and 10 deletions
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19
lib/valueflow.cpp
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@ -1908,25 +1908,22 @@ static void valueFlowAST(Token *tok, nonneg int varid, const ValueFlow::Value &v
} }
/** if known variable is changed in loop body, change it to a possible value */ /** if known variable is changed in loop body, change it to a possible value */
static void handleKnownValuesInLoop(const Token *startToken, static bool handleKnownValuesInLoop(const Token *startToken,
const Token *endToken, const Token *endToken,
std::list<ValueFlow::Value> *values, std::list<ValueFlow::Value> *values,
nonneg int varid, nonneg int varid,
bool globalvar, bool globalvar,
const Settings *settings) const Settings *settings)
{ {
bool isChanged = false; const bool isChanged = isVariableChanged(startToken, endToken, varid, globalvar, settings, true);
if (!isChanged)
return false;
for (std::list<ValueFlow::Value>::iterator it = values->begin(); it != values->end(); ++it) { for (std::list<ValueFlow::Value>::iterator it = values->begin(); it != values->end(); ++it) {
if (it->isKnown()) { if (it->isKnown()) {
if (!isChanged) {
if (!isVariableChanged(startToken, endToken, varid, globalvar, settings, true))
break;
isChanged = true;
}
it->setPossible(); it->setPossible();
} }
} }
return isChanged;
} }
static bool evalAssignment(ValueFlow::Value &lhsValue, const std::string &assign, const ValueFlow::Value &rhsValue) static bool evalAssignment(ValueFlow::Value &lhsValue, const std::string &assign, const ValueFlow::Value &rhsValue)
@ -2113,8 +2110,10 @@ static bool valueFlowForward(Token * const startToken,
} }
// if known variable is changed in loop body, change it to a possible value.. // if known variable is changed in loop body, change it to a possible value..
if (Token::Match(tok2, "for|while")) if (Token::Match(tok2, "for|while")) {
handleKnownValuesInLoop(tok2, tok2->linkAt(1)->linkAt(1), &values, varid, var->isGlobal(), settings); if (handleKnownValuesInLoop(tok2, tok2->linkAt(1)->linkAt(1), &values, varid, var->isGlobal(), settings))
number_of_if++;
}
// Set values in condition // Set values in condition
for (Token* tok3 = tok2->tokAt(2); tok3 != tok2->next()->link(); tok3 = tok3->next()) { for (Token* tok3 = tok2->tokAt(2); tok3 != tok2->next()->link(); tok3 = tok3->next()) {

15
test/testvalueflow.cpp
View File

@ -1912,6 +1912,21 @@ private:
"}\n"; "}\n";
ASSERT_EQUALS(true, testValueOfX(code, 9U, 0)); // x can be 0 at line 9 ASSERT_EQUALS(true, testValueOfX(code, 9U, 0)); // x can be 0 at line 9
code = "void f(const int *buf) {\n"
" int x = 111;\n"
" bool found = false;\n"
" for (int i = 0; i < 10; i++) {\n"
" if (buf[i] == 123) {\n"
" x = i;\n"
" found = true;\n"
" break;\n"
" }\n"
" }\n"
" if (found)\n"
" a = x;\n" // <- x can't be 111
"}\n";
ASSERT_EQUALS(false, testValueOfX(code, 12U, 111)); // x can not be 111 at line 9
code = "void f(const int *buf) {\n" code = "void f(const int *buf) {\n"
" int x = 0;\n" " int x = 0;\n"
" for (int i = 0; i < 10; i++) {\n" " for (int i = 0; i < 10; i++) {\n"