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Uninitialized variables: Improved checking of functions

This commit is contained in:
Daniel Marjamäki 2012-12-20 19:45:30 +01:00
parent d82048f5f5
commit ccdea4dc2b
3 changed files with 90 additions and 16 deletions
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60
lib/checkuninitvar.cpp
View File

@ -1080,7 +1080,7 @@ void CheckUninitVar::checkScope(const Scope* scope)
while (tok && tok->str() != ";")
tok = tok->next();
if (stdtype || i->isPointer())
checkScopeForVariable(tok, *i, NULL, NULL);
checkScopeForVariable(scope, tok, *i, NULL, NULL);
}
for (std::list<Scope*>::const_iterator i = scope->nestedList.begin(); i != scope->nestedList.end(); ++i) {
@ -1089,7 +1089,7 @@ void CheckUninitVar::checkScope(const Scope* scope)
}
}
bool CheckUninitVar::checkScopeForVariable(const Token *tok, const Variable& var, bool * const possibleInit, bool * const noreturn)
bool CheckUninitVar::checkScopeForVariable(const Scope* scope, const Token *tok, const Variable& var, bool * const possibleInit, bool * const noreturn)
{
const bool suppressErrors(possibleInit && *possibleInit);
@ -1118,7 +1118,7 @@ bool CheckUninitVar::checkScopeForVariable(const Token *tok, const Variable& var
// Unconditional inner scope..
if (tok->str() == "{" && Token::Match(tok->previous(), "[;{}]")) {
if (checkScopeForVariable(tok->next(), var, possibleInit, NULL))
if (checkScopeForVariable(scope, tok->next(), var, possibleInit, NULL))
return true;
tok = tok->link();
continue;
@ -1131,7 +1131,7 @@ bool CheckUninitVar::checkScopeForVariable(const Token *tok, const Variable& var
// Inner scope..
if (Token::simpleMatch(tok, "if (")) {
// initialization / usage in condition..
if (checkIfForWhileHead(tok->next(), var, suppressErrors, bool(number_of_if == 0)))
if (checkIfForWhileHead(scope, tok->next(), var, suppressErrors, bool(number_of_if == 0)))
return true;
// checking if a not-zero variable is zero => bail out
@ -1146,7 +1146,7 @@ bool CheckUninitVar::checkScopeForVariable(const Token *tok, const Variable& var
if (tok->str() == "{") {
bool possibleInitIf(number_of_if > 0 || suppressErrors);
bool noreturnIf = false;
const bool initif = checkScopeForVariable(tok->next(), var, &possibleInitIf, &noreturnIf);
const bool initif = checkScopeForVariable(scope, tok->next(), var, &possibleInitIf, &noreturnIf);
// goto the }
tok = tok->link();
@ -1163,7 +1163,7 @@ bool CheckUninitVar::checkScopeForVariable(const Token *tok, const Variable& var
bool possibleInitElse(number_of_if > 0 || suppressErrors);
bool noreturnElse = false;
const bool initelse = checkScopeForVariable(tok->next(), var, &possibleInitElse, NULL);
const bool initelse = checkScopeForVariable(scope, tok->next(), var, &possibleInitElse, NULL);
// goto the }
tok = tok->link();
@ -1201,7 +1201,7 @@ bool CheckUninitVar::checkScopeForVariable(const Token *tok, const Variable& var
// for/while..
if (Token::Match(tok, "for|while (")) {
// is variable initialized in for-head (don't report errors yet)?
if (checkIfForWhileHead(tok->next(), var, true, false))
if (checkIfForWhileHead(scope, tok->next(), var, true, false))
return true;
// goto the {
@ -1209,7 +1209,7 @@ bool CheckUninitVar::checkScopeForVariable(const Token *tok, const Variable& var
if (tok2 && tok2->str() == "{") {
bool possibleinit = true;
bool init = checkScopeForVariable(tok2->next(), var, &possibleinit, NULL);
bool init = checkScopeForVariable(scope, tok2->next(), var, &possibleinit, NULL);
// variable is initialized in the loop..
if (possibleinit || init)
@ -1217,7 +1217,7 @@ bool CheckUninitVar::checkScopeForVariable(const Token *tok, const Variable& var
// is variable used in for-head?
if (!suppressErrors) {
checkIfForWhileHead(tok->next(), var, false, bool(number_of_if == 0));
checkIfForWhileHead(scope, tok->next(), var, false, bool(number_of_if == 0));
}
// goto "}"
@ -1246,7 +1246,7 @@ bool CheckUninitVar::checkScopeForVariable(const Token *tok, const Variable& var
// variable is seen..
if (tok->varId() == var.varId()) {
// Use variable
if (!suppressErrors && isVariableUsage(tok, var.isPointer()))
if (!suppressErrors && isVariableUsage(scope, tok, var.isPointer()))
uninitvarError(tok, tok->str());
else
@ -1258,12 +1258,12 @@ bool CheckUninitVar::checkScopeForVariable(const Token *tok, const Variable& var
return ret;
}
bool CheckUninitVar::checkIfForWhileHead(const Token *startparanthesis, const Variable& var, bool suppressErrors, bool isuninit)
bool CheckUninitVar::checkIfForWhileHead(const Scope *scope, const Token *startparanthesis, const Variable& var, bool suppressErrors, bool isuninit)
{
const Token * const endpar = startparanthesis->link();
for (const Token *tok = startparanthesis->next(); tok && tok != endpar; tok = tok->next()) {
if (tok->varId() == var.varId()) {
if (isVariableUsage(tok, var.isPointer())) {
if (isVariableUsage(scope, tok, var.isPointer())) {
if (!suppressErrors)
uninitvarError(tok, tok->str());
else
@ -1279,11 +1279,45 @@ bool CheckUninitVar::checkIfForWhileHead(const Token *startparanthesis, const Va
return false;
}
bool CheckUninitVar::isVariableUsage(const Token *vartok, bool pointer) const
bool CheckUninitVar::isVariableUsage(const Scope* scope, const Token *vartok, bool pointer) const
{
if (vartok->previous()->str() == "return")
return true;
// Passing variable to function..
if (Token::Match(vartok->previous(), "[(,] %var% [,)]") || Token::Match(vartok->tokAt(-2), "[(,] & %var% [,)]")) {
const bool address(vartok->previous()->str() == "&");
// locate start parenthesis in function call..
int argumentNumber = 0;
const Token *start = vartok;
while (start && !Token::Match(start, "[;{}(]")) {
if (start->str() == ")")
start = start->link();
else if (start->str() == ",")
++argumentNumber;
start = start->previous();
}
// is this a function call?
if (start && Token::Match(start->previous(), "%var% (")) {
// check how function handle uninitialized data arguments..
const Function *func = _tokenizer->getSymbolDatabase()->findFunctionByNameAndArgs(start->previous(), scope);
if (func) {
const Variable *arg = func->getArgumentVar(argumentNumber);
if (arg) {
const Token *argStart = arg->typeStartToken();
while (argStart->previous() && argStart->previous()->isName())
argStart = argStart->previous();
if (argStart->isStandardType() && Token::Match(argStart, "%type% %var% [,)]"))
return true;
if (Token::Match(argStart, "const"))
return true;
}
}
}
}
if (Token::Match(vartok->previous(), "++|--|%op%")) {
if (vartok->previous()->str() == ">>" && _tokenizer->isCPP()) {
// assume that variable is initialized

6
lib/checkuninitvar.h
View File

@ -64,9 +64,9 @@ public:
/** Check for uninitialized variables */
void check();
void checkScope(const Scope* scope);
bool checkScopeForVariable(const Token *tok, const Variable& var, bool * const possibleInit, bool * const noreturn);
bool checkIfForWhileHead(const Token *startparanthesis, const Variable& var, bool suppressErrors, bool isuninit);
bool isVariableUsage(const Token *vartok, bool ispointer) const;
bool checkScopeForVariable(const Scope* scope, const Token *tok, const Variable& var, bool * const possibleInit, bool * const noreturn);
bool checkIfForWhileHead(const Scope *scope, const Token *startparanthesis, const Variable& var, bool suppressErrors, bool isuninit);
bool isVariableUsage(const Scope* scope, const Token *vartok, bool ispointer) const;
/**

40
test/testuninitvar.cpp
View File

@ -57,6 +57,7 @@ private:
TEST_CASE(uninitvar4); // #3869 (reference)
TEST_CASE(uninitvar5); // #3861
TEST_CASE(uninitvar6); // handling unknown types in C and C++ files
TEST_CASE(uninitvar2_func); // function calls
}
void checkUninitVar(const char code[], const char filename[] = "test.cpp") {
@ -2373,6 +2374,45 @@ private:
checkUninitVar2(code, "test.c");
ASSERT_EQUALS("[test.c:3]: (error) Uninitialized variable: a\n", errout.str());
}
// Handling of unknown types. Assume they are POD in C.
void uninitvar2_func() {
checkUninitVar2("void a(char c);\n"
"void b() {\n"
" char c;\n"
" a(c);\n"
"}");
ASSERT_EQUALS("[test.cpp:4]: (error) Uninitialized variable: c\n", errout.str());
checkUninitVar2("void a(const char *s);\n"
"void b() {\n"
" char c;\n"
" a(&c);\n"
"}");
ASSERT_EQUALS("[test.cpp:4]: (error) Uninitialized variable: c\n", errout.str());
checkUninitVar2("void a(char *s);\n"
"void b() {\n"
" char c;\n"
" a(&c);\n"
"}");
ASSERT_EQUALS("", errout.str());
checkUninitVar2("void a(const ABC *abc);\n"
"void b() {\n"
" ABC abc;\n"
" a(&abc);\n"
"}");
ASSERT_EQUALS("", errout.str());
checkUninitVar2("void a(const ABC *abc);\n"
"void b() {\n"
" ABC abc;\n"
" a(&abc);\n"
"}", "test.c");
ASSERT_EQUALS("[test.c:4]: (error) Uninitialized variable: abc\n", errout.str());
}
};
REGISTER_TEST(TestUninitVar)