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Fix 10290: false negative: container out of bounds #3269

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Merged
orbitcowboy merged 1 commit into from
May 22, 2021
Merged

Fix 10290: false negative: container out of bounds #3269

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6 changes: 4 additions & 2 deletions lib/forwardanalyzer.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -111,8 +111,10 @@ struct ForwardTraversal {
return Progress::Skip;
T* firstOp = tok->astOperand1();
T* secondOp = tok->astOperand2();
// Evaluate RHS of assignment before LHS
if (tok->isAssignmentOp())
// Evaluate:
// 1. RHS of assignment before LHS
// 2. Unary op before operand
if (tok->isAssignmentOp() || !secondOp)
std::swap(firstOp, secondOp);
if (firstOp && traverseRecursive(firstOp, f, traverseUnknown, recursion+1) == Progress::Break)
return Break();
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4 changes: 2 additions & 2 deletions lib/valueflow.cpp
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Expand Up @@ -1244,7 +1244,7 @@ static void valueFlowPointerAlias(TokenList *tokenlist)
}
}

static void valueFlowPointerAliasDeref(TokenList *tokenlist)
static void valueFlowUninitPointerAliasDeref(TokenList *tokenlist)
{
for (Token *tok = tokenlist->front(); tok; tok = tok->next()) {
if (!tok->isUnaryOp("*"))
Expand Down Expand Up @@ -6869,7 +6869,6 @@ void ValueFlow::setValues(TokenList *tokenlist, SymbolDatabase* symboldatabase,
while (n > 0 && values < getTotalValues(tokenlist)) {
values = getTotalValues(tokenlist);
valueFlowImpossibleValues(tokenlist, settings);
valueFlowPointerAliasDeref(tokenlist);
valueFlowArrayBool(tokenlist);
valueFlowRightShift(tokenlist, settings);
valueFlowAfterMove(tokenlist, symboldatabase, errorLogger, settings);
Expand All @@ -6883,6 +6882,7 @@ void ValueFlow::setValues(TokenList *tokenlist, SymbolDatabase* symboldatabase,
valueFlowLifetime(tokenlist, symboldatabase, errorLogger, settings);
valueFlowFunctionDefaultParameter(tokenlist, symboldatabase, errorLogger, settings);
valueFlowUninit(tokenlist, symboldatabase, errorLogger, settings);
valueFlowUninitPointerAliasDeref(tokenlist);
if (tokenlist->isCPP()) {
valueFlowSmartPointer(tokenlist, errorLogger, settings);
valueFlowIterators(tokenlist, settings);
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7 changes: 7 additions & 0 deletions test/teststl.cpp
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Expand Up @@ -440,6 +440,13 @@ class TestStl : public TestFixture {
" (*PArr)[i] = 1;\n"
"}\n");
ASSERT_EQUALS("", errout.str());

checkNormal("int f() {\n"
" std::vector<int> v;\n"
" std::vector<int> * pv = &v;\n"
" return (*pv).at(42);\n"
"}\n");
ASSERT_EQUALS("test.cpp:4:error:Out of bounds access in expression '(*pv).at(42)' because '*pv' is empty and 'at' may be non-zero.\n", errout.str());
}

void outOfBoundsIndexExpression() {
Expand Down