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uninitialized variables: added check

This commit is contained in:
Daniel Marjamäki 2009-10-29 21:34:43 +01:00
parent 4a61bd0432
commit c6d7fad84f
3 changed files with 194 additions and 1 deletions
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130
lib/checkother.cpp
View File

@ -1160,6 +1160,131 @@ void CheckOther::nullPointer()
nullPointerConditionalAssignment();
}
static const Token *uninitvar_checkscope(const Token *tok, const unsigned int varid, bool &init)
{
/* limit the checking in conditional code..
* int x;
* if (y)
* x = 33;
* if (y)
* return x;
*/
bool limit = false;
for (; tok; tok = tok->next())
{
if (tok->str() == "}")
return 0;
// todo: handle for/while
if (Token::Match(tok, "for|while"))
{
init = true;
return 0;
}
if (tok->str() == "if")
{
bool canInit = false;
bool ifInit = true;
while (tok->str() == "if")
{
// goto "("
tok = tok->next();
// goto ")"
tok = tok ? tok->link() : 0;
// goto "{"
tok = tok ? tok->next() : 0;
if (!Token::simpleMatch(tok, "{"))
return 0;
// Recursively check into the if ..
bool init2 = false;
const Token *tokerr = uninitvar_checkscope(tok->next(), varid, init2);
if (!limit && tokerr)
return tokerr;
// if the scope didn't initialize then this whole if-chain is treated as non-initializing
ifInit &= init2;
canInit |= init2;
// goto "}"
tok = tok->link();
// there is no else => not initialized
if (Token::Match(tok, "} !!else"))
{
ifInit = false;
break;
}
// parse next "if"..
tok = tok->tokAt(2);
if (tok->str() == "if")
continue;
// there is no "if"..
init2 = false;
tokerr = uninitvar_checkscope(tok->next(), varid, init2);
if (!limit && tokerr)
return tokerr;
ifInit &= init2;
canInit |= init2;
tok = tok->link();
if (!tok)
return 0;
}
if (ifInit)
{
init = true;
return 0;
}
if (canInit)
{
limit = true;
}
}
if (Token::Match(tok, "%varid% =", varid))
{
init = true;
return 0;
}
if (Token::Match(tok, "return| %varid% .|", varid))
return tok;
}
return 0;
}
void CheckOther::uninitvar()
{
const Token *tok = _tokenizer->tokens();
while (0 != (tok = Token::findmatch(tok, "[{};] %type% *| %var% ;")))
{
// goto the variable
tok = tok->tokAt(2);
if (tok->str() == "*")
tok = tok->next();
// check that the variable id is non-zero
if (tok->varId() == 0)
continue;
bool init = false;
const Token *tokerr = uninitvar_checkscope(tok->next(), tok->varId(), init);
if (tokerr)
uninitvarError(tokerr, tok->str());
}
}
void CheckOther::checkZeroDivision()
{
for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
@ -1301,6 +1426,11 @@ void CheckOther::nullPointerError(const Token *tok, const std::string &varname,
reportError(tok, Severity::error, "nullPointer", "Possible null pointer dereference: " + varname + " - otherwise it is redundant to check if " + varname + " is null at line " + MathLib::toString<long>(line));
}
void CheckOther::uninitvarError(const Token *tok, const std::string &varname)
{
reportError(tok, Severity::error, "uninitvar", "Uninitialized variable: " + varname);
}
void CheckOther::zerodivError(const Token *tok)
{
reportError(tok, Severity::error, "zerodiv", "Division by zero");

10
lib/checkother.h
View File

@ -76,6 +76,7 @@ public:
checkOther.strPlusChar();
checkOther.invalidFunctionUsage();
checkOther.checkZeroDivision();
checkOther.uninitvar();
}
// Casting
@ -111,6 +112,9 @@ public:
/** possible null pointer dereference */
void nullPointer();
/** reading uninitialized var */
void uninitvar();
/** Check zero division*/
void checkZeroDivision();
@ -124,6 +128,7 @@ public:
// haystack.remove(needle);
void redundantCondition2();
// Error messages..
void cstyleCastError(const Token *tok);
void redundantIfDelete0Error(const Token *tok);
@ -142,6 +147,7 @@ public:
void strPlusChar(const Token *tok);
void nullPointerError(const Token *tok, const std::string &varname);
void nullPointerError(const Token *tok, const std::string &varname, const int line);
void uninitvarError(const Token *tok, const std::string &varname);
void zerodivError(const Token *tok);
void postIncrementError(const Token *tok, const std::string &var_name, const bool isIncrement);
@ -151,6 +157,7 @@ public:
sprintfOverlappingDataError(0, "varname");
udivError(0);
nullPointerError(0, "pointer");
uninitvarError(0, "varname");
zerodivError(0);
// style
@ -186,7 +193,7 @@ public:
" * division with zero\n"
" * null pointer dereferencing\n"
// warning
// style
" * C-style pointer cast in cpp file\n"
" * redundant if\n"
" * bad usage of the function 'strtol'\n"
@ -198,6 +205,7 @@ public:
" * variable scope can be limited\n"
" * condition that is always true/false\n"
" * unusal pointer arithmetic. For example: \"abc\" + 'd'\n"
" * uninitialized variables\n"
// optimisations
" * optimisation: detect post increment/decrement\n";

55
test/testother.cpp
View File

@ -68,6 +68,8 @@ private:
TEST_CASE(nullpointer5); // References should not be checked
TEST_CASE(nullpointer6);
TEST_CASE(uninitvar1);
TEST_CASE(oldStylePointerCast);
TEST_CASE(postIncrementDecrementStl);
@ -910,6 +912,59 @@ private:
ASSERT_EQUALS("", errout.str());
}
void checkUninitVar(const char code[])
{
// Tokenize..
Tokenizer tokenizer;
std::istringstream istr(code);
tokenizer.tokenize(istr, "test.cpp");
// Clear the error buffer..
errout.str("");
// Check for redundant code..
Settings settings;
settings._checkCodingStyle = true;
CheckOther checkOther(&tokenizer, &settings, this);
checkOther.uninitvar();
}
void uninitvar1()
{
checkUninitVar("static void foo()\n"
"{\n"
" Foo *p;\n"
" if (x)\n"
" p = new Foo;\n"
" p->abcd();\n"
"}\n");
ASSERT_EQUALS("[test.cpp:6]: (error) Uninitialized variable: p\n", errout.str());
checkUninitVar("int foo()\n"
"{\n"
" int i;\n"
" if (x)\n"
" i = 22;\n"
" else\n"
" i = 33;\n"
" return i;\n"
"}\n");
ASSERT_EQUALS("", errout.str());
checkUninitVar("static void foo()\n"
"{\n"
" Foo *p;\n"
" if (x)\n"
" p = new Foo;\n"
" if (x)\n"
" p->abcd();\n"
"}\n");
ASSERT_EQUALS("", errout.str());
}
void checkOldStylePointerCast(const char code[])
{
// Tokenize..