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

Fixed #3233 (false positive: (style) Checking if unsigned variable 'i' is less than zero.)

This commit is contained in:
Daniel Marjamäki 2011-11-06 18:24:37 +01:00
parent 95851454cc
commit fa076598ad
3 changed files with 55 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

50
lib/checkother.cpp
View File

@ -2558,6 +2558,10 @@ void CheckOther::checkSignOfUnsignedVariable()
if (!_settings->isEnabled("style"))
return;
const bool inconclusive = _tokenizer->codeWithTemplates();
if (inconclusive && !_settings->inconclusive)
return;
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
std::list<Scope>::const_iterator scope;
@ -2572,36 +2576,54 @@ void CheckOther::checkSignOfUnsignedVariable()
if (Token::Match(tok, ";|(|&&|%oror% %var% <|<= 0 ;|)|&&|%oror%") && tok->next()->varId()) {
const Variable * var = symbolDatabase->getVariableFromVarId(tok->next()->varId());
if (var && var->typeEndToken()->isUnsigned())
unsignedLessThanZeroError(tok->next(), tok->next()->str());
unsignedLessThanZeroError(tok->next(), tok->next()->str(), inconclusive);
} else if (Token::Match(tok, ";|(|&&|%oror% 0 > %var% ;|)|&&|%oror%") && tok->tokAt(3)->varId()) {
const Variable * var = symbolDatabase->getVariableFromVarId(tok->tokAt(3)->varId());
if (var && var->typeEndToken()->isUnsigned())
unsignedLessThanZeroError(tok->tokAt(3), tok->strAt(3));
unsignedLessThanZeroError(tok->tokAt(3), tok->strAt(3), inconclusive);
} else if (Token::Match(tok, ";|(|&&|%oror% 0 <= %var% ;|)|&&|%oror%") && tok->tokAt(3)->varId()) {
const Variable * var = symbolDatabase->getVariableFromVarId(tok->tokAt(3)->varId());
if (var && var->typeEndToken()->isUnsigned())
unsignedPositiveError(tok->tokAt(3), tok->strAt(3));
unsignedPositiveError(tok->tokAt(3), tok->strAt(3), inconclusive);
} else if (Token::Match(tok, ";|(|&&|%oror% %var% >= 0 ;|)|&&|%oror%") && tok->next()->varId()) {
const Variable * var = symbolDatabase->getVariableFromVarId(tok->next()->varId());
if (var && var->typeEndToken()->isUnsigned())
unsignedPositiveError(tok->next(), tok->next()->str());
unsignedPositiveError(tok->next(), tok->next()->str(), inconclusive);
}
}
}
}
void CheckOther::unsignedLessThanZeroError(const Token *tok, const std::string &varname)
void CheckOther::unsignedLessThanZeroError(const Token *tok, const std::string &varname, bool inconclusive)
{
reportError(tok, Severity::style, "unsignedLessThanZero",
"Checking if unsigned variable '" + varname + "' is less than zero.\n"
"An unsigned variable will never be negative so it is either pointless or "
"an error to check if it is.");
if (inconclusive) {
reportInconclusiveError(tok, Severity::style, "unsignedLessThanZero",
"Checking if unsigned variable '" + varname + "' is less than zero. This might be a false warning.\n"
"Checking if unsigned variable '" + varname + "' is less than zero. An unsigned "
"variable will never be negative so it is either pointless or an error to check if it is. "
"It's not known if the used constant is a template parameter or not and therefore "
"this message might be a false warning");
} else {
reportError(tok, Severity::style, "unsignedLessThanZero",
"Checking if unsigned variable '" + varname + "' is less than zero.\n"
"An unsigned variable will never be negative so it is either pointless or "
"an error to check if it is.");
}
}
void CheckOther::unsignedPositiveError(const Token *tok, const std::string &varname)
void CheckOther::unsignedPositiveError(const Token *tok, const std::string &varname, bool inconclusive)
{
reportError(tok, Severity::style, "unsignedPositive",
"Checking if unsigned variable '" + varname + "' is positive is always true.\n"
"An unsigned variable will always be positive so it is either pointless or "
"an error to check if it is.");
if (inconclusive) {
reportInconclusiveError(tok, Severity::style, "unsignedPositive",
"Checking if unsigned variable '" + varname + "' is positive is always true. This might be a false warning.\n"
"Checking if unsigned variable '" + varname + "' is positive is always true. "
"An unsigned variable will always be positive so it is either pointless or "
"an error to check if it is. It's not known if the used constant is a "
"template parameter or not and therefore this message might be a false warning");
} else {
reportError(tok, Severity::style, "unsignedPositive",
"Checking if unsigned variable '" + varname + "' is positive is always true.\n"
"An unsigned variable will always be positive so it is either pointless or "
"an error to check if it is.");
}
}

8
lib/checkother.h
View File

@ -289,8 +289,8 @@ public:
void alwaysTrueStringVariableCompareError(const Token *tok, const std::string& str1, const std::string& str2);
void duplicateBreakError(const Token *tok);
void assignBoolToPointerError(const Token *tok);
void unsignedLessThanZeroError(const Token *tok, const std::string &varname);
void unsignedPositiveError(const Token *tok, const std::string &varname);
void unsignedLessThanZeroError(const Token *tok, const std::string &varname, bool inconclusive);
void unsignedPositiveError(const Token *tok, const std::string &varname, bool inconclusive);
void bitwiseOnBooleanError(const Token *tok, const std::string &varname, const std::string &op);
void comparisonOfBoolExpressionWithIntError(const Token *tok);
void SuspiciousSemicolonError(const Token *tok);
@ -343,8 +343,8 @@ public:
c.alwaysTrueFalseStringCompareError(0, "str1", "str2");
c.alwaysTrueStringVariableCompareError(0, "varname1", "varname2");
c.duplicateBreakError(0);
c.unsignedLessThanZeroError(0, "varname");
c.unsignedPositiveError(0, "varname");
c.unsignedLessThanZeroError(0, "varname", false);
c.unsignedPositiveError(0, "varname", false);
c.bitwiseOnBooleanError(0, "varname", "&&");
c.comparisonOfBoolExpressionWithIntError(0);
c.SuspiciousSemicolonError(0);

16
test/testother.cpp
View File

@ -3527,12 +3527,13 @@ private:
ASSERT_EQUALS("[test.cpp:4]: (warning) Passing sizeof(pointer) as the last argument to strncmp.\n", errout.str());
}
void check_signOfUnsignedVariable(const char code[]) {
void check_signOfUnsignedVariable(const char code[], bool inconclusive=false) {
// Clear the error buffer..
errout.str("");
Settings settings;
settings.addEnabled("style");
settings.inconclusive = inconclusive;
// Tokenize..
Tokenizer tokenizer(&settings, this);
@ -3753,6 +3754,19 @@ private:
" return false;\n"
"}");
ASSERT_EQUALS("", errout.str());
// #3233 - FP when template is used (template parameter is numeric constant)
{
const char code[] =
"template<int n> void foo(unsigned int x) {\n"
" if (x <= n);\n"
"}\n"
"foo<0>();";
check_signOfUnsignedVariable(code, false);
ASSERT_EQUALS("", errout.str());
check_signOfUnsignedVariable(code, true);
ASSERT_EQUALS("[test.cpp:2]: (style) Checking if unsigned variable 'x' is less than zero. This might be a false warning.\n", errout.str());
}
}
void checkForSuspiciousSemicolon1() {