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Add check for comparison of identical string variables

This commit is contained in:
Richard Quirk 2011-10-28 22:05:11 +02:00
parent 4ba6ac7332
commit 90c7db15a0
3 changed files with 31 additions and 0 deletions
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19
lib/checkother.cpp
View File

@ -2257,6 +2257,7 @@ void CheckOther::checkAlwaysTrueOrFalseStringCompare()
const char pattern1[] = "strncmp|strcmp|stricmp|strcmpi|strcasecmp|wcscmp ( %str% , %str% ";
const char pattern2[] = "QString :: compare ( %str% , %str% )";
const char pattern3[] = "strncmp|strcmp|stricmp|strcmpi|strcasecmp|wcscmp ( %var% , %var% ";
const Token *tok = _tokenizer->tokens();
while (tok && (tok = Token::findmatch(tok, pattern1)) != NULL) {
@ -2269,6 +2270,14 @@ void CheckOther::checkAlwaysTrueOrFalseStringCompare()
alwaysTrueFalseStringCompareError(tok, tok->strAt(4), tok->strAt(6));
tok = tok->tokAt(7);
}
tok = _tokenizer->tokens();
while (tok && (tok = Token::findmatch(tok, pattern3)) != NULL) {
const Token *var1 = tok->tokAt(2);
const Token *var2 = tok->tokAt(4);
alwaysTrueStringVariableCompareError(tok, var1->str(), var2->str());
tok = tok->tokAt(5);
}
}
void CheckOther::alwaysTrueFalseStringCompareError(const Token *tok, const std::string& str1, const std::string& str2)
@ -2291,6 +2300,16 @@ void CheckOther::alwaysTrueFalseStringCompareError(const Token *tok, const std::
}
}
void CheckOther::alwaysTrueStringVariableCompareError(const Token *tok, const std::string& str1, const std::string& str2)
{
if (str1 == str2) {
reportError(tok, Severity::warning, "stringCompare",
"Comparison of identical string variables.\n"
"The compared strings, '" + str1 + "' and '" + str2 + "', are identical. "
"This could be a logic bug.");
}
}
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
void CheckOther::sizeofsizeof()

2
lib/checkother.h
View File

@ -273,6 +273,7 @@ public:
void duplicateBranchError(const Token *tok1, const Token *tok2);
void duplicateExpressionError(const Token *tok1, const Token *tok2, const std::string &op);
void alwaysTrueFalseStringCompareError(const Token *tok, const std::string& str1, const std::string& str2);
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);
@ -326,6 +327,7 @@ public:
c.duplicateBranchError(0, 0);
c.duplicateExpressionError(0, 0, "&&");
c.alwaysTrueFalseStringCompareError(0, "str1", "str2");
c.alwaysTrueStringVariableCompareError(0, "varname1", "varname2");
c.duplicateBreakError(0);
c.unsignedLessThanZeroError(0, "varname");
c.unsignedPositiveError(0, "varname");

10
test/testother.cpp
View File

@ -3428,6 +3428,16 @@ private:
" }"
"}");
ASSERT_EQUALS("[test.cpp:3]: (warning) Comparison of always identical static strings.\n", errout.str());
check_preprocess_suppress(
"int foo(const char *buf)\n"
"{\n"
" if (strcmp(buf, buf) == 0)"
" {"
" std::cout << \"Equal\n\""
" }"
"}");
ASSERT_EQUALS("[test.cpp:3]: (warning) Comparison of identical string variables.\n", errout.str());
}
void check_signOfUnsignedVariable(const char code[]) {