walkero
/
cppcheck
1
0
Fork 0
Code Issues Pull Requests Projects Releases 1 Wiki Activity

Fix #10358 Bad ValueFlow depending on initialization (#5052)

This commit is contained in:
chrchr-github 2023-05-12 07:19:44 +02:00 committed by GitHub
parent 59b955e014
commit 2a0143c8e1
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 28 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
lib/valueflow.cpp
View File

@ -1336,6 +1336,13 @@ static Token * valueFlowSetConstantValue(Token *tok, const Settings *settings, b
} }
// skip over enum // skip over enum
tok = tok->linkAt(1); tok = tok->linkAt(1);
} else if (Token::Match(tok, "%name% [{(] [)}]") && (tok->isStandardType() ||
(tok->variable() && tok->variable()->nameToken() == tok &&
(tok->variable()->isPointer() || (tok->variable()->valueType() && tok->variable()->valueType()->isIntegral()))))) {
ValueFlow::Value value(0);
if (!tok->isTemplateArg())
value.setKnown();
setTokenValue(tok->next(), std::move(value), settings, isInitList);
} }
return tok->next(); return tok->next();
} }
@ -5770,7 +5777,7 @@ static std::list<ValueFlow::Value> truncateValues(std::list<ValueFlow::Value> va
static bool isVariableInit(const Token *tok) static bool isVariableInit(const Token *tok)
{ {
return (tok->str() == "(" || tok->str() == "{") && return (tok->str() == "(" || tok->str() == "{") &&
tok->isBinaryOp() && (tok->isBinaryOp() || (tok->astOperand1() && tok->link() == tok->next())) &&
tok->astOperand1()->variable() && tok->astOperand1()->variable() &&
tok->astOperand1()->variable()->nameToken() == tok->astOperand1() && tok->astOperand1()->variable()->nameToken() == tok->astOperand1() &&
tok->astOperand1()->variable()->valueType() && tok->astOperand1()->variable()->valueType() &&
@ -5803,7 +5810,8 @@ static void valueFlowAfterAssign(TokenList *tokenlist,
std::unordered_map<nonneg int, std::unordered_set<nonneg int>> backAssigns; std::unordered_map<nonneg int, std::unordered_set<nonneg int>> backAssigns;
for (Token* tok = const_cast<Token*>(scope->bodyStart); tok != scope->bodyEnd; tok = tok->next()) { for (Token* tok = const_cast<Token*>(scope->bodyStart); tok != scope->bodyEnd; tok = tok->next()) {
// Assignment // Assignment
if (tok->str() != "=" && !isVariableInit(tok)) bool isInit = false;
if (tok->str() != "=" && !(isInit = isVariableInit(tok)))
continue; continue;
if (tok->astParent() && !(tok->astParent()->str() == ";" && astIsLHS(tok))) if (tok->astParent() && !(tok->astParent()->str() == ";" && astIsLHS(tok)))
@ -5815,11 +5823,14 @@ static void valueFlowAfterAssign(TokenList *tokenlist,
std::vector<const Variable*> vars = getLHSVariables(tok); std::vector<const Variable*> vars = getLHSVariables(tok);
// Rhs values.. // Rhs values..
if (!tok->astOperand2() || tok->astOperand2()->values().empty()) Token* rhs = tok->astOperand2();
if (!rhs && isInit)
rhs = tok;
if (!rhs || rhs->values().empty())
continue; continue;
std::list<ValueFlow::Value> values = truncateValues( std::list<ValueFlow::Value> values = truncateValues(
tok->astOperand2()->values(), tok->astOperand1()->valueType(), tok->astOperand2()->valueType(), settings); rhs->values(), tok->astOperand1()->valueType(), rhs->valueType(), settings);
// Remove known values // Remove known values
std::set<ValueFlow::Value::ValueType> types; std::set<ValueFlow::Value::ValueType> types;
if (tok->astOperand1()->hasKnownValue()) { if (tok->astOperand1()->hasKnownValue()) {
@ -5874,7 +5885,7 @@ static void valueFlowAfterAssign(TokenList *tokenlist,
continue; continue;
const bool init = vars.size() == 1 && (vars.front()->nameToken() == tok->astOperand1() || tok->isSplittedVarDeclEq()); const bool init = vars.size() == 1 && (vars.front()->nameToken() == tok->astOperand1() || tok->isSplittedVarDeclEq());
valueFlowForwardAssign( valueFlowForwardAssign(
tok->astOperand2(), tok->astOperand1(), vars, values, init, tokenlist, errorLogger, settings); rhs, tok->astOperand1(), vars, values, init, tokenlist, errorLogger, settings);
// Back propagate symbolic values // Back propagate symbolic values
if (tok->astOperand1()->exprId() > 0) { if (tok->astOperand1()->exprId() > 0) {
Token* start = nextAfterAstRightmostLeaf(tok); Token* start = nextAfterAstRightmostLeaf(tok);

16
test/testvalueflow.cpp
View File

@ -5035,16 +5035,24 @@ private:
" return s == 0;\n" // <- known value " return s == 0;\n" // <- known value
"}"; "}";
value = valueOfTok(code, "=="); value = valueOfTok(code, "==");
TODO_ASSERT_EQUALS(true, false, value.isKnown()); ASSERT_EQUALS(true, value.isKnown());
TODO_ASSERT_EQUALS(1, 0, value.intvalue); ASSERT_EQUALS(1, value.intvalue);
code = "bool f() {\n" code = "bool f() {\n"
" const int s = int();" " const int s = int();"
" return s == 0;\n" // <- known value " return s == 0;\n" // <- known value
"}"; "}";
value = valueOfTok(code, "=="); value = valueOfTok(code, "==");
TODO_ASSERT_EQUALS(true, false, value.isKnown()); ASSERT_EQUALS(true, value.isKnown());
TODO_ASSERT_EQUALS(1, 0, value.intvalue); ASSERT_EQUALS(1, value.intvalue);
code = "bool f() {\n"
" const int s{};"
" return s == 0;\n" // <- known value
"}";
value = valueOfTok(code, "==");
ASSERT_EQUALS(true, value.isKnown());
ASSERT_EQUALS(1, value.intvalue);
// calculation with known result // calculation with known result
code = "int f(int x) { a = x & 0; }"; // <- & is 0 code = "int f(int x) { a = x & 0; }"; // <- & is 0