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Fix 9953: false positive: uninitvar (#3548)

This commit is contained in:
Paul Fultz II 2021-11-07 00:51:19 -05:00 committed by GitHub
parent 6338c2396c
commit 1791457227
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GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 9 additions and 38 deletions
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37
lib/valueflow.cpp
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@ -1317,42 +1317,6 @@ static void valueFlowPointerAlias(TokenList *tokenlist)
}
}
static void valueFlowUninitPointerAliasDeref(TokenList *tokenlist)
{
for (Token *tok = tokenlist->front(); tok; tok = tok->next()) {
if (!tok->isUnaryOp("*"))
continue;
if (!astIsPointer(tok->astOperand1()))
continue;
const Token* lifeTok = nullptr;
ErrorPath errorPath;
for (const ValueFlow::Value& v:tok->astOperand1()->values()) {
if (!v.isLocalLifetimeValue())
continue;
lifeTok = v.tokvalue;
errorPath = v.errorPath;
}
if (!lifeTok)
continue;
if (lifeTok->varId() == 0)
continue;
const Variable * var = lifeTok->variable();
if (!var)
continue;
if (!var->isConst() && isVariableChanged(lifeTok->next(), tok, lifeTok->varId(), !var->isLocal(), tokenlist->getSettings(), tokenlist->isCPP()))
continue;
for (const ValueFlow::Value& v:lifeTok->values()) {
// Forward uninit values since not all values can be forwarded directly
if (!v.isUninitValue())
continue;
ValueFlow::Value value = v;
value.errorPath.insert(value.errorPath.begin(), errorPath.begin(), errorPath.end());
setTokenValue(tok, value, tokenlist->getSettings());
}
}
}
static void valueFlowBitAnd(TokenList *tokenlist)
{
for (Token *tok = tokenlist->front(); tok; tok = tok->next()) {
@ -7698,7 +7662,6 @@ void ValueFlow::setValues(TokenList *tokenlist, SymbolDatabase* symboldatabase,
valueFlowLifetime(tokenlist, symboldatabase, errorLogger, settings);
valueFlowFunctionDefaultParameter(tokenlist, symboldatabase, settings);
valueFlowUninit(tokenlist, symboldatabase, settings);
valueFlowUninitPointerAliasDeref(tokenlist);
if (tokenlist->isCPP()) {
valueFlowAfterMove(tokenlist, symboldatabase, settings);
valueFlowSmartPointer(tokenlist, errorLogger, settings);

10
test/testuninitvar.cpp
View File

@ -5358,6 +5358,14 @@ private:
"}");
ASSERT_EQUALS("[test.cpp:7] -> [test.cpp:2]: (error) Uninitialized variable: *buflen\n", errout.str());
// # 9953
valueFlowUninit("uint32_t f(uint8_t *mem) {\n"
" uint32_t u32;\n"
" uint8_t *buf = (uint8_t *)(&u32);\n"
" buf[0] = mem[0];\n"
" return(*(uint32_t *)buf);\n"
"}\n");
ASSERT_EQUALS("", errout.str());
}
void valueFlowUninitStructMembers()
@ -5427,7 +5435,7 @@ private:
" x = *(&ab);\n"
"}\n",
"test.c");
ASSERT_EQUALS("[test.c:5] -> [test.c:5]: (error) Uninitialized variable: *(&ab).b\n", errout.str());
ASSERT_EQUALS("[test.c:5]: (error) Uninitialized variable: *(&ab).b\n", errout.str());
valueFlowUninit("void f(void) {\n"
" struct AB ab;\n"