cppcheck/lib/checkinternal.cpp

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/*
* Cppcheck - A tool for static C/C++ code analysis
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* Copyright (C) 2007-2020 Cppcheck team.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifdef CHECK_INTERNAL
#include "checkinternal.h"
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#include "astutils.h"
#include "symboldatabase.h"
#include "token.h"
#include "tokenize.h"
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#include <set>
#include <cstring>
// Register this check class (by creating a static instance of it).
// Disabled in release builds
namespace {
CheckInternal instance;
}
void CheckInternal::checkTokenMatchPatterns()
{
const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
for (const Scope *scope : symbolDatabase->functionScopes) {
for (const Token* tok = scope->bodyStart->next(); tok != scope->bodyEnd; tok = tok->next()) {
if (!Token::simpleMatch(tok, "Token :: Match (") && !Token::simpleMatch(tok, "Token :: findmatch ("))
continue;
const std::string& funcname = tok->strAt(2);
// Get pattern string
const Token *patternTok = tok->tokAt(4)->nextArgument();
if (!patternTok || patternTok->tokType() != Token::eString)
continue;
const std::string pattern = patternTok->strValue();
if (pattern.empty()) {
simplePatternError(tok, pattern, funcname);
continue;
}
if (pattern.find("||") != std::string::npos || pattern.find(" | ") != std::string::npos || pattern[0] == '|' || (pattern[pattern.length() - 1] == '|' && pattern[pattern.length() - 2] == ' '))
orInComplexPattern(tok, pattern, funcname);
// Check for signs of complex patterns
if (pattern.find_first_of("[|") != std::string::npos)
continue;
else if (pattern.find("!!") != std::string::npos)
continue;
bool complex = false;
size_t index = pattern.find('%');
while (index != std::string::npos) {
if (pattern.length() <= index + 2) {
complex = true;
break;
}
if (pattern[index + 1] == 'o' && pattern[index + 2] == 'r') // %or% or %oror%
index = pattern.find('%', index + 1);
else {
complex = true;
break;
}
index = pattern.find('%', index + 1);
}
if (!complex)
simplePatternError(tok, pattern, funcname);
}
}
}
void CheckInternal::checkRedundantTokCheck()
{
for (const Token *tok = mTokenizer->tokens(); tok; tok = tok->next()) {
if (Token::Match(tok, "&& Token :: simpleMatch|Match|findsimplematch|findmatch (")) {
// in code like
// if (tok->previous() && Token::match(tok->previous(), "bla")) {}
// the first tok->previous() check is redundant
const Token *astOp1 = tok->astOperand1();
const Token *astOp2 = getArguments(tok->tokAt(3))[0];
if (Token::simpleMatch(astOp1, "&&")) {
astOp1 = astOp1->astOperand2();
}
if (astOp1->expressionString() == astOp2->expressionString()) {
checkRedundantTokCheckError(astOp2);
}
// if (!tok || !Token::match(tok, "foo"))
} else if (Token::Match(tok, "%oror% ! Token :: simpleMatch|Match|findsimplematch|findmatch (")) {
const Token *negTok = tok->next()->astParent()->astOperand1();
if (Token::simpleMatch(negTok, "||")) {
negTok = negTok->astOperand2();
}
// the first tok condition is negated
if (Token::simpleMatch(negTok, "!")) {
const Token *astOp1 = negTok->astOperand1();
const Token *astOp2 = getArguments(tok->tokAt(4))[0];
if (astOp1->expressionString() == astOp2->expressionString()) {
checkRedundantTokCheckError(astOp2);
}
}
}
}
}
void CheckInternal::checkRedundantTokCheckError(const Token* tok)
{
reportError(tok, Severity::style, "redundantTokCheck",
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"Unnecessary check of \"" + (tok? tok->expressionString(): emptyString) + "\", match-function already checks if it is null.");
}
void CheckInternal::checkTokenSimpleMatchPatterns()
{
const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
for (const Scope* scope : symbolDatabase->functionScopes) {
for (const Token* tok = scope->bodyStart->next(); tok != scope->bodyEnd; tok = tok->next()) {
if (!Token::simpleMatch(tok, "Token :: simpleMatch (") && !Token::simpleMatch(tok, "Token :: findsimplematch ("))
continue;
const std::string& funcname = tok->strAt(2);
// Get pattern string
const Token *patternTok = tok->tokAt(4)->nextArgument();
if (!patternTok || patternTok->tokType() != Token::eString)
continue;
const std::string pattern = patternTok->strValue();
if (pattern.empty()) {
complexPatternError(tok, pattern, funcname);
continue;
}
// Check for [xyz] usage - but exclude standalone square brackets
unsigned int char_count = 0;
for (char c : pattern) {
if (c == ' ') {
char_count = 0;
} else if (c == ']') {
if (char_count > 0) {
complexPatternError(tok, pattern, funcname);
continue;
}
} else {
++char_count;
}
}
// Check | usage: Count characters before the symbol
char_count = 0;
for (char c : pattern) {
if (c == ' ') {
char_count = 0;
} else if (c == '|') {
if (char_count > 0) {
complexPatternError(tok, pattern, funcname);
continue;
}
} else {
++char_count;
}
}
// Check for real errors
if (pattern.length() > 1) {
for (size_t j = 0; j < pattern.length() - 1; j++) {
if (pattern[j] == '%' && pattern[j + 1] != ' ')
complexPatternError(tok, pattern, funcname);
else if (pattern[j] == '!' && pattern[j + 1] == '!')
complexPatternError(tok, pattern, funcname);
}
}
}
}
}
namespace {
const std::set<std::string> knownPatterns = {
"%any%"
, "%assign%"
, "%bool%"
, "%char%"
, "%comp%"
, "%num%"
, "%op%"
, "%cop%"
, "%or%"
, "%oror%"
, "%str%"
, "%type%"
, "%name%"
, "%var%"
, "%varid%"
};
}
void CheckInternal::checkMissingPercentCharacter()
{
const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
for (const Scope* scope : symbolDatabase->functionScopes) {
for (const Token* tok = scope->bodyStart->next(); tok != scope->bodyEnd; tok = tok->next()) {
if (!Token::simpleMatch(tok, "Token :: Match (") && !Token::simpleMatch(tok, "Token :: findmatch ("))
continue;
const std::string& funcname = tok->strAt(2);
// Get pattern string
const Token *patternTok = tok->tokAt(4)->nextArgument();
if (!patternTok || patternTok->tokType() != Token::eString)
continue;
const std::string pattern = patternTok->strValue();
std::set<std::string>::const_iterator knownPattern, knownPatternsEnd = knownPatterns.end();
for (knownPattern = knownPatterns.begin(); knownPattern != knownPatternsEnd; ++knownPattern) {
const std::string brokenPattern = (*knownPattern).substr(0, (*knownPattern).size() - 1);
std::string::size_type pos = 0;
while ((pos = pattern.find(brokenPattern, pos)) != std::string::npos) {
// Check if it's the full pattern
if (pattern.find(*knownPattern, pos) != pos) {
// Known whitelist of substrings
if ((brokenPattern == "%var" && pattern.find("%varid%", pos) == pos) ||
(brokenPattern == "%or" && pattern.find("%oror%", pos) == pos)) {
++pos;
continue;
}
missingPercentCharacterError(tok, pattern, funcname);
}
++pos;
}
}
}
}
}
void CheckInternal::checkUnknownPattern()
{
const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
for (const Scope* scope : symbolDatabase->functionScopes) {
for (const Token* tok = scope->bodyStart->next(); tok != scope->bodyEnd; tok = tok->next()) {
if (!Token::simpleMatch(tok, "Token :: Match (") && !Token::simpleMatch(tok, "Token :: findmatch ("))
continue;
// Get pattern string
const Token *patternTok = tok->tokAt(4)->nextArgument();
if (!patternTok || patternTok->tokType() != Token::eString)
continue;
const std::string pattern = patternTok->strValue();
bool inBrackets = false;
for (std::string::size_type j = 0; j < pattern.length() - 1; j++) {
if (pattern[j] == '[' && (j == 0 || pattern[j - 1] == ' '))
inBrackets = true;
else if (pattern[j] == ']')
inBrackets = false;
else if (pattern[j] == '%' && pattern[j + 1] != ' ' && pattern[j + 1] != '|' && !inBrackets) {
const std::string::size_type end = pattern.find('%', j + 1);
if (end != std::string::npos) {
const std::string s = pattern.substr(j, end - j + 1);
if (knownPatterns.find(s) == knownPatterns.end())
unknownPatternError(tok, s);
}
}
}
}
}
}
void CheckInternal::checkRedundantNextPrevious()
{
const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
for (const Scope* scope : symbolDatabase->functionScopes) {
for (const Token* tok = scope->bodyStart->next(); tok != scope->bodyEnd; tok = tok->next()) {
if (tok->str() != ".")
continue;
tok = tok->next();
if (Token::Match(tok, "previous ( ) . next|tokAt|strAt|linkAt (") || Token::Match(tok, "next ( ) . previous|tokAt|strAt|linkAt (") ||
(Token::simpleMatch(tok, "tokAt (") && Token::Match(tok->linkAt(1), ") . previous|next|tokAt|strAt|linkAt|str|link ("))) {
const std::string& func1 = tok->str();
const std::string& func2 = tok->linkAt(1)->strAt(2);
if ((func2 == "previous" || func2 == "next" || func2 == "str" || func2 == "link") && tok->linkAt(1)->strAt(4) != ")")
continue;
redundantNextPreviousError(tok, func1, func2);
} else if (Token::Match(tok, "next|previous ( ) . next|previous ( ) . next|previous|linkAt|strAt|link|str (")) {
const std::string& func1 = tok->str();
const std::string& func2 = tok->strAt(8);
if ((func2 == "previous" || func2 == "next" || func2 == "str" || func2 == "link") && tok->strAt(10) != ")")
continue;
redundantNextPreviousError(tok, func1, func2);
}
}
}
}
void CheckInternal::checkExtraWhitespace()
{
const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
for (const Scope* scope : symbolDatabase->functionScopes) {
for (const Token* tok = scope->bodyStart->next(); tok != scope->bodyEnd; tok = tok->next()) {
if (!Token::Match(tok, "Token :: simpleMatch|findsimplematch|Match|findmatch ("))
continue;
const std::string& funcname = tok->strAt(2);
// Get pattern string
const Token *patternTok = tok->tokAt(4)->nextArgument();
if (!patternTok || patternTok->tokType() != Token::eString)
continue;
const std::string pattern = patternTok->strValue();
if (!pattern.empty() && (pattern[0] == ' ' || *pattern.rbegin() == ' '))
extraWhitespaceError(tok, pattern, funcname);
// two whitespaces or more
if (pattern.find(" ") != std::string::npos)
extraWhitespaceError(tok, pattern, funcname);
}
}
}
void CheckInternal::checkStlUsage()
{
const SymbolDatabase *symbolDatabase = mTokenizer->getSymbolDatabase();
for (const Scope *scope : symbolDatabase->functionScopes) {
for (const Token* tok = scope->bodyStart->next(); tok != scope->bodyEnd; tok = tok->next()) {
if (Token::simpleMatch(tok, ". emplace ("))
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reportError(tok, Severity::error, "internalStlUsage", "The 'emplace' function shall be avoided for now. It is not available e.g. in Slackware 14.0. 'emplace_back' is fine.");
//if (Token::simpleMatch(tok, ". back ( )") && tok->astOperand1() && tok->astOperand1()->valueType() && tok->astOperand1()->valueType()->container && Token::simpleMatch(tok->astOperand1()->valueType()->container, "std :: string"))
// reportError(tok, Severity::error, "internalStlUsage", "The 'std::string::back()' function shall be avoided for now.");
}
}
}
void CheckInternal::multiComparePatternError(const Token* tok, const std::string& pattern, const std::string &funcname)
{
reportError(tok, Severity::error, "multiComparePatternError",
"Bad multicompare pattern (a %cmd% must be first unless it is %or%,%op%,%cop%,%name%,%oror%) inside Token::" + funcname + "() call: \"" + pattern + "\""
);
}
void CheckInternal::simplePatternError(const Token* tok, const std::string& pattern, const std::string &funcname)
{
reportError(tok, Severity::warning, "simplePatternError",
"Found simple pattern inside Token::" + funcname + "() call: \"" + pattern + "\""
);
}
void CheckInternal::complexPatternError(const Token* tok, const std::string& pattern, const std::string &funcname)
{
reportError(tok, Severity::error, "complexPatternError",
"Found complex pattern inside Token::" + funcname + "() call: \"" + pattern + "\""
);
}
void CheckInternal::missingPercentCharacterError(const Token* tok, const std::string& pattern, const std::string& funcname)
{
reportError(tok, Severity::error, "missingPercentCharacter",
"Missing percent end character in Token::" + funcname + "() pattern: \"" + pattern + "\""
);
}
void CheckInternal::unknownPatternError(const Token* tok, const std::string& pattern)
{
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reportError(tok, Severity::error, "unknownPattern",
"Unknown pattern used: \"" + pattern + "\"");
}
void CheckInternal::redundantNextPreviousError(const Token* tok, const std::string& func1, const std::string& func2)
{
reportError(tok, Severity::style, "redundantNextPrevious",
"Call to 'Token::" + func1 + "()' followed by 'Token::" + func2 + "()' can be simplified.");
}
void CheckInternal::orInComplexPattern(const Token* tok, const std::string& pattern, const std::string &funcname)
{
reportError(tok, Severity::error, "orInComplexPattern",
"Token::" + funcname + "() pattern \"" + pattern + "\" contains \"||\" or \"|\". Replace it by \"%oror%\" or \"%or%\".");
}
void CheckInternal::extraWhitespaceError(const Token* tok, const std::string& pattern, const std::string &funcname)
{
reportError(tok, Severity::warning, "extraWhitespaceError",
"Found extra whitespace inside Token::" + funcname + "() call: \"" + pattern + "\""
);
}
#endif // #ifdef CHECK_INTERNAL