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Try again to clarify warning message for new strcmp() checker

This commit is contained in:
Daniel Marjamäki 2017-12-13 15:28:50 +01:00
parent a6983dd279
commit d292434e76
3 changed files with 13 additions and 18 deletions
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15
lib/checkstring.cpp
View File

@ -336,7 +336,7 @@ void CheckString::incorrectStringBooleanError(const Token *tok, const std::strin
// always true: strcmp(str,"a")==0 || strcmp(str,"b")
// TODO: Library configuration for string comparison functions
//---------------------------------------------------------------------------
void CheckString::deadStrcmp()
void CheckString::overlappingStrcmp()
{
if (!_settings->isEnabled(Settings::WARNING))
return;
@ -399,29 +399,24 @@ void CheckString::deadStrcmp()
args2[1]->isLiteral() &&
args1[1]->str() != args2[1]->str() &&
isSameExpression(_tokenizer->isCPP(), true, args1[0], args2[0], _settings->library, true))
deadStrcmpError(tok1, tok2);
overlappingStrcmpError(tok1, tok2);
}
}
}
}
}
void CheckString::deadStrcmpError(const Token *eq0, const Token *ne0)
void CheckString::overlappingStrcmpError(const Token *eq0, const Token *ne0)
{
std::string eq0Expr(eq0 ? eq0->expressionString() : std::string("strcmp(x,\"abc\")"));
if (eq0 && eq0->astParent()->str() == "!")
eq0Expr = "!" + eq0Expr;
else
eq0Expr += " == 0";
const std::string ne0Expr = (ne0 ? ne0->expressionString() : std::string("strcmp(x,\"def\")")) + " != 0";
const Token *ortok = eq0;
while (ortok && ortok->str() != "||")
ortok = ortok->astParent();
const std::string expression = ortok ? ortok->expressionString() : (eq0Expr + " || " + ne0Expr);
reportError(ne0, Severity::warning, "deadStrcmp", "The expression '" + expression + "' has a dead string comparison. The expression is logically the same as \'" + ne0Expr + "\'.");
reportError(ne0, Severity::warning, "overlappingStrcmp", "The expression '" + ne0Expr + "' is suspicious. It overlaps '" + eq0Expr + "'.");
}
//---------------------------------------------------------------------------

12
lib/checkstring.h
View File

@ -57,7 +57,7 @@ public:
checkString.strPlusChar();
checkString.checkSuspiciousStringCompare();
checkString.stringLiteralWrite();
checkString.deadStrcmp();
checkString.overlappingStrcmp();
}
/** @brief Run checks against the simplified token list */
@ -85,8 +85,8 @@ public:
/** @brief %Check for suspicious code that compares string literals for equality */
void checkAlwaysTrueOrFalseStringCompare();
/** @brief %Check for dead string comparison */
void deadStrcmp();
/** @brief %Check for overlapping strcmp() */
void overlappingStrcmp();
/** @brief %Check for overlapping source and destination passed to sprintf() */
void sprintfOverlappingData();
@ -101,7 +101,7 @@ private:
void alwaysTrueStringVariableCompareError(const Token *tok, const std::string& str1, const std::string& str2);
void suspiciousStringCompareError(const Token* tok, const std::string& var);
void suspiciousStringCompareError_char(const Token* tok, const std::string& var);
void deadStrcmpError(const Token* tok1, const Token *tok2);
void overlappingStrcmpError(const Token* tok1, const Token *tok2);
void getErrorMessages(ErrorLogger *errorLogger, const Settings *settings) const {
CheckString c(nullptr, settings, errorLogger);
@ -115,7 +115,7 @@ private:
c.incorrectStringBooleanError(nullptr, "\"Hello World\"");
c.alwaysTrueFalseStringCompareError(nullptr, "str1", "str2");
c.alwaysTrueStringVariableCompareError(nullptr, "varname1", "varname2");
c.deadStrcmpError(nullptr, nullptr);
c.overlappingStrcmpError(nullptr, nullptr);
}
static std::string myName() {
@ -130,7 +130,7 @@ private:
"- suspicious condition (string literals as boolean)\n"
"- suspicious comparison of a string literal with a char* variable\n"
"- suspicious comparison of '\\0' with a char* variable\n"
"- dead string comparison; (strcmp(str,\"x\")==0 || strcmp(str,\"y\")) is logically the same as (strcmp(str,\"y\") != 0)\n";
"- overlapping strcmp() expression\n";
}
};
/// @}

4
test/teststring.cpp
View File

@ -585,7 +585,7 @@ private:
check("void f(const char *str) {\n"
" if (strcmp(str, \"abc\") == 0 || strcmp(str, \"def\")) {}\n"
"}");
ASSERT_EQUALS("[test.cpp:2]: (warning) The expression 'strcmp(str,\"abc\")==0||strcmp(str,\"def\")' has a dead string comparison. The expression is logically the same as 'strcmp(str,\"def\") != 0'.\n", errout.str());
ASSERT_EQUALS("[test.cpp:2]: (warning) The expression 'strcmp(str,\"def\") != 0' is suspicious. It overlaps 'strcmp(str,\"abc\") == 0'.\n", errout.str());
check("struct X {\n"
" char *str;\n"
@ -594,7 +594,7 @@ private:
"void f(const struct X *x) {\n"
" if (strcmp(x->str, \"abc\") == 0 || strcmp(x->str, \"def\")) {}\n"
"}");
ASSERT_EQUALS("[test.cpp:6]: (warning) The expression 'strcmp(x->str,\"abc\")==0||strcmp(x->str,\"def\")' has a dead string comparison. The expression is logically the same as 'strcmp(x->str,\"def\") != 0'.\n", errout.str());
ASSERT_EQUALS("[test.cpp:6]: (warning) The expression 'strcmp(x->str,\"def\") != 0' is suspicious. It overlaps 'strcmp(x->str,\"abc\") == 0'.\n", errout.str());
}
};