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Fixed #10273 (False negative; Uninitialized variable in for loop)

This commit is contained in:
Daniel Marjamäki 2021-05-11 20:35:15 +02:00
parent c77caf637c
commit 22ab9ccd7f
3 changed files with 66 additions and 20 deletions
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75
lib/checkuninitvar.cpp
View File

@ -814,20 +814,40 @@ bool CheckUninitVar::checkIfForWhileHead(const Token *startparentheses, const Va
return false;
}
bool CheckUninitVar::checkLoopBody(const Token *tok, const Variable& var, const Alloc alloc, const std::string &membervar, const bool suppressErrors)
/** recursively check loop, return error token */
const Token* CheckUninitVar::checkLoopBodyRecursive(const Token *start, const Variable& var, const Alloc alloc, const std::string &membervar, bool &bailout) const
{
const Token *usetok = nullptr;
assert(start->str() == "{");
assert(tok->str() == "{");
const Token *errorToken = nullptr;
for (const Token * const end = tok->link(); tok != end; tok = tok->next()) {
const Token *const end = start->link();
for (const Token *tok = start->next(); tok != end; tok = tok->next()) {
if (Token::Match(tok, "sizeof|typeof (")) {
tok = tok->next()->link();
tok = tok->linkAt(1);
continue;
}
if (Token::Match(tok, "asm ( %str% ) ;"))
return true;
if (Token::Match(tok, "asm ( %str% ) ;")) {
bailout = true;
return nullptr;
}
if (tok->str() == "{") {
const Token *errorToken1 = checkLoopBodyRecursive(tok, var, alloc, membervar, bailout);
if (Token::simpleMatch(tok->link(), "} else {")) {
const Token *elseBody = tok->link()->tokAt(2);
const Token *errorToken2 = checkLoopBodyRecursive(elseBody, var, alloc, membervar, bailout);
if (errorToken1 && errorToken2)
return errorToken1;
if (errorToken2)
errorToken = errorToken2;
}
if (bailout)
return nullptr;
if (errorToken1)
errorToken = errorToken1;
}
if (tok->varId() != var.declarationId())
continue;
@ -860,17 +880,21 @@ bool CheckUninitVar::checkLoopBody(const Token *tok, const Variable& var, const
break;
}
}
if (assign)
return true;
if (assign) {
bailout = true;
return nullptr;
}
}
if (isMemberVariableUsage(tok, var.isPointer(), alloc, membervar))
usetok = tok;
else if (Token::Match(tok->previous(), "[(,] %name% [,)]"))
return true;
return tok;
else if (Token::Match(tok->previous(), "[(,] %name% [,)]")) {
bailout = true;
return nullptr;
}
} else {
if (isVariableUsage(tok, var.isPointer(), alloc))
usetok = tok;
return tok;
else if (tok->strAt(1) == "=") {
bool varIsUsedInRhs = false;
visitAstNodes(tok->next()->astOperand2(), [&](const Token * t) {
@ -884,23 +908,34 @@ bool CheckUninitVar::checkLoopBody(const Token *tok, const Variable& var, const
return ChildrenToVisit::none;
return ChildrenToVisit::op1_and_op2;
});
if (!varIsUsedInRhs)
return true;
if (!varIsUsedInRhs) {
bailout = true;
return nullptr;
}
} else {
return true;
bailout = true;
return nullptr;
}
}
}
if (!suppressErrors && usetok) {
return errorToken;
}
bool CheckUninitVar::checkLoopBody(const Token *tok, const Variable& var, const Alloc alloc, const std::string &membervar, const bool suppressErrors)
{
bool bailout = false;
const Token *errorToken = checkLoopBodyRecursive(tok, var, alloc, membervar, bailout);
if (!suppressErrors && !bailout && errorToken) {
if (membervar.empty())
uninitvarError(usetok, usetok->str(), alloc);
uninitvarError(errorToken, errorToken->str(), alloc);
else
uninitStructMemberError(usetok, usetok->str() + "." + membervar);
uninitStructMemberError(errorToken, errorToken->str() + "." + membervar);
return true;
}
return false;
return bailout;
}
void CheckUninitVar::checkRhs(const Token *tok, const Variable &var, Alloc alloc, nonneg int number_of_if, const std::string &membervar)

1
lib/checkuninitvar.h
View File

@ -81,6 +81,7 @@ public:
bool checkScopeForVariable(const Token *tok, const Variable& var, bool* const possibleInit, bool* const noreturn, Alloc* const alloc, const std::string &membervar, std::map<nonneg int, VariableValue> variableValue);
bool checkIfForWhileHead(const Token *startparentheses, const Variable& var, bool suppressErrors, bool isuninit, Alloc alloc, const std::string &membervar);
bool checkLoopBody(const Token *tok, const Variable& var, const Alloc alloc, const std::string &membervar, const bool suppressErrors);
const Token* checkLoopBodyRecursive(const Token *start, const Variable& var, const Alloc alloc, const std::string &membervar, bool &bailout) const;
void checkRhs(const Token *tok, const Variable &var, Alloc alloc, nonneg int number_of_if, const std::string &membervar);
bool isVariableUsage(const Token *vartok, bool pointer, Alloc alloc, int indirect = 0) const;
int isFunctionParUsage(const Token *vartok, bool pointer, Alloc alloc, int indirect = 0) const;

10
test/testuninitvar.cpp
View File

@ -1255,6 +1255,16 @@ private:
" *c = 0;\n"
"}");
ASSERT_EQUALS("", errout.str());
// #10273 - assignment in conditional code
checkUninitVar("void foo() {\n"
" int learn;\n"
" for (int index = 0; index < 10; index++) {\n"
" if (!(learn & PORT_LEARN_DISABLE))\n"
" learn = 123;\n"
" }\n"
"}");
ASSERT_EQUALS("[test.cpp:4]: (error) Uninitialized variable: learn\n", errout.str());
}
// switch..