/*
* Cppcheck - A tool for static C/C++ code analysis
* Copyright (C) 2007-2019 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 .
*/
#include "errorlogger.h"
#include "cppcheck.h"
#include "mathlib.h"
#include "path.h"
#include "token.h"
#include "tokenlist.h"
#include "utils.h"
#include
#include
#include
#include
#include
#include
#include
InternalError::InternalError(const Token *tok, const std::string &errorMsg, Type type) :
token(tok), errorMessage(errorMsg), type(type)
{
switch (type) {
case AST:
id = "internalAstError";
break;
case SYNTAX:
id = "syntaxError";
break;
case UNKNOWN_MACRO:
id = "unknownMacro";
break;
case INTERNAL:
id = "cppcheckError";
break;
case LIMIT:
id = "cppcheckLimit";
break;
}
}
ErrorLogger::ErrorMessage::ErrorMessage()
: _severity(Severity::none), _cwe(0U), _inconclusive(false)
{
}
ErrorLogger::ErrorMessage::ErrorMessage(const std::list &callStack, const std::string& file1, Severity::SeverityType severity, const std::string &msg, const std::string &id, bool inconclusive) :
_callStack(callStack), // locations for this error message
_id(id), // set the message id
file0(file1),
_severity(severity), // severity for this error message
_cwe(0U),
_inconclusive(inconclusive)
{
// set the summary and verbose messages
setmsg(msg);
}
ErrorLogger::ErrorMessage::ErrorMessage(const std::list &callStack, const std::string& file1, Severity::SeverityType severity, const std::string &msg, const std::string &id, const CWE &cwe, bool inconclusive) :
_callStack(callStack), // locations for this error message
_id(id), // set the message id
file0(file1),
_severity(severity), // severity for this error message
_cwe(cwe.id),
_inconclusive(inconclusive)
{
// set the summary and verbose messages
setmsg(msg);
}
ErrorLogger::ErrorMessage::ErrorMessage(const std::list& callstack, const TokenList* list, Severity::SeverityType severity, const std::string& id, const std::string& msg, bool inconclusive)
: _id(id), _severity(severity), _cwe(0U), _inconclusive(inconclusive)
{
// Format callstack
for (std::list::const_iterator it = callstack.begin(); it != callstack.end(); ++it) {
// --errorlist can provide null values here
if (!(*it))
continue;
_callStack.emplace_back(*it, list);
}
if (list && !list->getFiles().empty())
file0 = list->getFiles()[0];
setmsg(msg);
}
ErrorLogger::ErrorMessage::ErrorMessage(const std::list& callstack, const TokenList* list, Severity::SeverityType severity, const std::string& id, const std::string& msg, const CWE &cwe, bool inconclusive)
: _id(id), _severity(severity), _cwe(cwe.id), _inconclusive(inconclusive)
{
// Format callstack
for (std::list::const_iterator it = callstack.begin(); it != callstack.end(); ++it) {
// --errorlist can provide null values here
if (!(*it))
continue;
_callStack.emplace_back(*it, list);
}
if (list && !list->getFiles().empty())
file0 = list->getFiles()[0];
setmsg(msg);
}
ErrorLogger::ErrorMessage::ErrorMessage(const ErrorPath &errorPath, const TokenList *tokenList, Severity::SeverityType severity, const char id[], const std::string &msg, const CWE &cwe, bool inconclusive)
: _id(id), _severity(severity), _cwe(cwe.id), _inconclusive(inconclusive)
{
// Format callstack
for (ErrorPath::const_iterator it = errorPath.begin(); it != errorPath.end(); ++it) {
const Token *tok = it->first;
const std::string &info = it->second;
// --errorlist can provide null values here
if (tok)
_callStack.emplace_back(tok, info, tokenList);
}
if (tokenList && !tokenList->getFiles().empty())
file0 = tokenList->getFiles()[0];
setmsg(msg);
}
ErrorLogger::ErrorMessage::ErrorMessage(const tinyxml2::XMLElement * const errmsg)
: _severity(Severity::none),
_cwe(0U),
_inconclusive(false)
{
const char * const unknown = "";
const char *attr = errmsg->Attribute("id");
_id = attr ? attr : unknown;
attr = errmsg->Attribute("severity");
_severity = attr ? Severity::fromString(attr) : Severity::none;
attr = errmsg->Attribute("cwe");
std::istringstream(attr ? attr : "0") >> _cwe.id;
attr = errmsg->Attribute("inconclusive");
_inconclusive = attr && (std::strcmp(attr, "true") == 0);
attr = errmsg->Attribute("msg");
mShortMessage = attr ? attr : "";
attr = errmsg->Attribute("verbose");
mVerboseMessage = attr ? attr : "";
for (const tinyxml2::XMLElement *e = errmsg->FirstChildElement(); e; e = e->NextSiblingElement()) {
if (std::strcmp(e->Name(),"location")==0) {
const char *strfile = e->Attribute("file");
const char *strinfo = e->Attribute("info");
const char *strline = e->Attribute("line");
const char *file = strfile ? strfile : unknown;
const char *info = strinfo ? strinfo : "";
const int line = strline ? std::atoi(strline) : 0;
_callStack.emplace_back(file, info, line);
}
}
}
void ErrorLogger::ErrorMessage::setmsg(const std::string &msg)
{
// If a message ends to a '\n' and contains only a one '\n'
// it will cause the mVerboseMessage to be empty which will show
// as an empty message to the user if --verbose is used.
// Even this doesn't cause problems with messages that have multiple
// lines, none of the error messages should end into it.
assert(!endsWith(msg,'\n'));
// The summary and verbose message are separated by a newline
// If there is no newline then both the summary and verbose messages
// are the given message
const std::string::size_type pos = msg.find('\n');
const std::string symbolName = mSymbolNames.empty() ? std::string() : mSymbolNames.substr(0, mSymbolNames.find('\n'));
if (pos == std::string::npos) {
mShortMessage = replaceStr(msg, "$symbol", symbolName);
mVerboseMessage = replaceStr(msg, "$symbol", symbolName);
} else if (msg.compare(0,8,"$symbol:") == 0) {
mSymbolNames += msg.substr(8, pos-7);
setmsg(msg.substr(pos + 1));
} else {
mShortMessage = replaceStr(msg.substr(0, pos), "$symbol", symbolName);
mVerboseMessage = replaceStr(msg.substr(pos + 1), "$symbol", symbolName);
}
}
Suppressions::ErrorMessage ErrorLogger::ErrorMessage::toSuppressionsErrorMessage() const
{
Suppressions::ErrorMessage ret;
ret.errorId = _id;
if (!_callStack.empty()) {
ret.setFileName(_callStack.back().getfile(false));
ret.lineNumber = _callStack.back().line;
}
ret.inconclusive = _inconclusive;
ret.symbolNames = mSymbolNames;
return ret;
}
std::string ErrorLogger::ErrorMessage::serialize() const
{
// Serialize this message into a simple string
std::ostringstream oss;
oss << _id.length() << " " << _id;
oss << Severity::toString(_severity).length() << " " << Severity::toString(_severity);
oss << MathLib::toString(_cwe.id).length() << " " << MathLib::toString(_cwe.id);
if (_inconclusive) {
const std::string inconclusive("inconclusive");
oss << inconclusive.length() << " " << inconclusive;
}
const std::string saneShortMessage = fixInvalidChars(mShortMessage);
const std::string saneVerboseMessage = fixInvalidChars(mVerboseMessage);
oss << saneShortMessage.length() << " " << saneShortMessage;
oss << saneVerboseMessage.length() << " " << saneVerboseMessage;
oss << _callStack.size() << " ";
for (std::list::const_iterator loc = _callStack.begin(); loc != _callStack.end(); ++loc) {
std::ostringstream smallStream;
smallStream << (*loc).line << ':' << (*loc).getfile() << '\t' << loc->getinfo();
oss << smallStream.str().length() << " " << smallStream.str();
}
return oss.str();
}
bool ErrorLogger::ErrorMessage::deserialize(const std::string &data)
{
_inconclusive = false;
_callStack.clear();
std::istringstream iss(data);
std::array results;
std::size_t elem = 0;
while (iss.good()) {
unsigned int len = 0;
if (!(iss >> len))
return false;
iss.get();
std::string temp;
for (unsigned int i = 0; i < len && iss.good(); ++i) {
const char c = static_cast(iss.get());
temp.append(1, c);
}
if (temp == "inconclusive") {
_inconclusive = true;
continue;
}
results[elem++] = temp;
if (elem == 5)
break;
}
if (elem != 5)
throw InternalError(nullptr, "Internal Error: Deserialization of error message failed");
_id = results[0];
_severity = Severity::fromString(results[1]);
std::istringstream scwe(results[2]);
scwe >> _cwe.id;
mShortMessage = results[3];
mVerboseMessage = results[4];
unsigned int stackSize = 0;
if (!(iss >> stackSize))
return false;
while (iss.good()) {
unsigned int len = 0;
if (!(iss >> len))
return false;
iss.get();
std::string temp;
for (unsigned int i = 0; i < len && iss.good(); ++i) {
const char c = static_cast(iss.get());
temp.append(1, c);
}
const std::string::size_type colonPos = temp.find(':');
if (colonPos == std::string::npos)
throw InternalError(nullptr, "Internal Error: No colon found in pattern");
const std::string::size_type tabPos = temp.find('\t');
if (tabPos == std::string::npos)
throw InternalError(nullptr, "Internal Error: No tab found in pattern");
const std::string tempinfo = temp.substr(tabPos + 1);
temp.erase(tabPos);
const std::string tempfile = temp.substr(colonPos + 1);
temp.erase(colonPos);
const std::string templine = temp;
ErrorLogger::ErrorMessage::FileLocation loc;
loc.setfile(tempfile);
loc.setinfo(tempinfo);
std::istringstream fiss(templine);
fiss >> loc.line;
_callStack.push_back(loc);
if (_callStack.size() >= stackSize)
break;
}
return true;
}
std::string ErrorLogger::ErrorMessage::getXMLHeader()
{
// xml_version 1 is the default xml format
tinyxml2::XMLPrinter printer;
// standard xml header
printer.PushDeclaration("xml version=\"1.0\" encoding=\"UTF-8\"");
// header
printer.OpenElement("results", false);
printer.PushAttribute("version", 2);
printer.OpenElement("cppcheck", false);
printer.PushAttribute("version", CppCheck::version());
printer.CloseElement(false);
printer.OpenElement("errors", false);
return std::string(printer.CStr()) + '>';
}
std::string ErrorLogger::ErrorMessage::getXMLFooter()
{
return " \n";
}
// There is no utf-8 support around but the strings should at least be safe for to tinyxml2.
// See #5300 "Invalid encoding in XML output" and #6431 "Invalid XML created - Invalid encoding of string literal "
std::string ErrorLogger::ErrorMessage::fixInvalidChars(const std::string& raw)
{
std::string result;
result.reserve(raw.length());
std::string::const_iterator from=raw.begin();
while (from!=raw.end()) {
if (std::isprint(static_cast(*from))) {
result.push_back(*from);
} else {
std::ostringstream es;
// straight cast to (unsigned) doesn't work out.
const unsigned uFrom = (unsigned char)*from;
es << '\\' << std::setbase(8) << std::setw(3) << std::setfill('0') << uFrom;
result += es.str();
}
++from;
}
return result;
}
std::string ErrorLogger::ErrorMessage::toXML() const
{
tinyxml2::XMLPrinter printer(nullptr, false, 2);
printer.OpenElement("error", false);
printer.PushAttribute("id", _id.c_str());
printer.PushAttribute("severity", Severity::toString(_severity).c_str());
printer.PushAttribute("msg", fixInvalidChars(mShortMessage).c_str());
printer.PushAttribute("verbose", fixInvalidChars(mVerboseMessage).c_str());
if (_cwe.id)
printer.PushAttribute("cwe", _cwe.id);
if (_inconclusive)
printer.PushAttribute("inconclusive", "true");
for (std::list::const_reverse_iterator it = _callStack.rbegin(); it != _callStack.rend(); ++it) {
printer.OpenElement("location", false);
if (!file0.empty() && (*it).getfile() != file0)
printer.PushAttribute("file0", Path::toNativeSeparators(file0).c_str());
printer.PushAttribute("file", (*it).getfile().c_str());
printer.PushAttribute("line", std::max((*it).line,0));
if (!it->getinfo().empty())
printer.PushAttribute("info", fixInvalidChars(it->getinfo()).c_str());
printer.CloseElement(false);
}
for (std::string::size_type pos = 0; pos < mSymbolNames.size();) {
const std::string::size_type pos2 = mSymbolNames.find('\n', pos);
std::string symbolName;
if (pos2 == std::string::npos) {
symbolName = mSymbolNames.substr(pos);
pos = pos2;
} else {
symbolName = mSymbolNames.substr(pos, pos2-pos);
pos = pos2 + 1;
}
printer.OpenElement("symbol", false);
printer.PushText(symbolName.c_str());
printer.CloseElement(false);
}
printer.CloseElement(false);
return printer.CStr();
}
void ErrorLogger::ErrorMessage::findAndReplace(std::string &source, const std::string &searchFor, const std::string &replaceWith)
{
std::string::size_type index = 0;
while ((index = source.find(searchFor, index)) != std::string::npos) {
source.replace(index, searchFor.length(), replaceWith);
index += replaceWith.length();
}
}
// TODO: read info from some shared resource instead?
static std::string readCode(const std::string &file, unsigned int linenr, unsigned int column, const char endl[])
{
std::ifstream fin(file);
std::string line;
while (linenr > 0 && std::getline(fin,line)) {
linenr--;
}
const std::string::size_type endPos = line.find_last_not_of("\r\n\t ");
if (endPos + 1 < line.size())
line.erase(endPos + 1);
std::string::size_type pos = 0;
while ((pos = line.find('\t', pos)) != std::string::npos)
line[pos] = ' ';
return line + endl + std::string((column>0 ? column-1 : column), ' ') + '^';
}
std::string ErrorLogger::ErrorMessage::toString(bool verbose, const std::string &templateFormat, const std::string &templateLocation) const
{
// Save this ErrorMessage in plain text.
// No template is given
if (templateFormat.empty()) {
std::ostringstream text;
if (!_callStack.empty())
text << callStackToString(_callStack) << ": ";
if (_severity != Severity::none) {
text << '(' << Severity::toString(_severity);
if (_inconclusive)
text << ", inconclusive";
text << ") ";
}
text << (verbose ? mVerboseMessage : mShortMessage);
return text.str();
}
// template is given. Reformat the output according to it
std::string result = templateFormat;
// Support a few special characters to allow to specific formatting, see http://sourceforge.net/apps/phpbb/cppcheck/viewtopic.php?f=4&t=494&sid=21715d362c0dbafd3791da4d9522f814
// Substitution should be done first so messages from cppcheck never get translated.
findAndReplace(result, "\\b", "\b");
findAndReplace(result, "\\n", "\n");
findAndReplace(result, "\\r", "\r");
findAndReplace(result, "\\t", "\t");
findAndReplace(result, "{id}", _id);
if (result.find("{inconclusive:") != std::string::npos) {
const std::string::size_type pos1 = result.find("{inconclusive:");
const std::string::size_type pos2 = result.find('}', pos1+1);
const std::string replaceFrom = result.substr(pos1,pos2-pos1+1);
const std::string replaceWith = _inconclusive ? result.substr(pos1+14, pos2-pos1-14) : std::string();
findAndReplace(result, replaceFrom, replaceWith);
}
findAndReplace(result, "{severity}", Severity::toString(_severity));
findAndReplace(result, "{cwe}", MathLib::toString(_cwe.id));
findAndReplace(result, "{message}", verbose ? mVerboseMessage : mShortMessage);
findAndReplace(result, "{callstack}", _callStack.empty() ? emptyString : callStackToString(_callStack));
if (!_callStack.empty()) {
findAndReplace(result, "{file}", _callStack.back().getfile());
findAndReplace(result, "{line}", MathLib::toString(_callStack.back().line));
findAndReplace(result, "{column}", MathLib::toString(_callStack.back().col));
if (result.find("{code}") != std::string::npos) {
const std::string::size_type pos = result.find('\r');
const char *endl;
if (pos == std::string::npos)
endl = "\n";
else if (pos+1 < result.size() && result[pos+1] == '\n')
endl = "\r\n";
else
endl = "\r";
findAndReplace(result, "{code}", readCode(_callStack.back().getOrigFile(), _callStack.back().line, _callStack.back().col, endl));
}
} else {
findAndReplace(result, "{file}", "nofile");
findAndReplace(result, "{line}", "0");
findAndReplace(result, "{column}", "0");
findAndReplace(result, "{code}", emptyString);
}
if (!templateLocation.empty() && _callStack.size() >= 2U) {
for (const FileLocation &fileLocation : _callStack) {
std::string text = templateLocation;
findAndReplace(text, "\\b", "\b");
findAndReplace(text, "\\n", "\n");
findAndReplace(text, "\\r", "\r");
findAndReplace(text, "\\t", "\t");
findAndReplace(text, "{file}", fileLocation.getfile());
findAndReplace(text, "{line}", MathLib::toString(fileLocation.line));
findAndReplace(text, "{column}", MathLib::toString(fileLocation.col));
findAndReplace(text, "{info}", fileLocation.getinfo().empty() ? mShortMessage : fileLocation.getinfo());
if (text.find("{code}") != std::string::npos) {
const std::string::size_type pos = text.find('\r');
const char *endl;
if (pos == std::string::npos)
endl = "\n";
else if (pos+1 < text.size() && text[pos+1] == '\n')
endl = "\r\n";
else
endl = "\r";
findAndReplace(text, "{code}", readCode(fileLocation.getOrigFile(), fileLocation.line, fileLocation.col, endl));
}
result += '\n' + text;
}
}
return result;
}
bool ErrorLogger::reportUnmatchedSuppressions(const std::list &unmatched)
{
bool err = false;
// Report unmatched suppressions
for (const Suppressions::Suppression &s : unmatched) {
// don't report "unmatchedSuppression" as unmatched
if (s.errorId == "unmatchedSuppression")
continue;
// check if this unmatched suppression is suppressed
bool suppressed = false;
for (const Suppressions::Suppression &s2 : unmatched) {
if (s2.errorId == "unmatchedSuppression") {
if ((s2.fileName == "*" || s2.fileName == s.fileName) &&
(s2.lineNumber == Suppressions::Suppression::NO_LINE || s2.lineNumber == s.lineNumber)) {
suppressed = true;
break;
}
}
}
if (suppressed)
continue;
std::list callStack;
if (!s.fileName.empty())
callStack.emplace_back(s.fileName, s.lineNumber);
reportErr(ErrorLogger::ErrorMessage(callStack, emptyString, Severity::information, "Unmatched suppression: " + s.errorId, "unmatchedSuppression", false));
err = true;
}
return err;
}
std::string ErrorLogger::callStackToString(const std::list &callStack)
{
std::ostringstream ostr;
for (std::list::const_iterator tok = callStack.begin(); tok != callStack.end(); ++tok) {
ostr << (tok == callStack.begin() ? "" : " -> ") << tok->stringify();
}
return ostr.str();
}
ErrorLogger::ErrorMessage::FileLocation::FileLocation(const Token* tok, const TokenList* tokenList)
: fileIndex(tok->fileIndex()), line(tok->linenr()), col(tok->col()), mOrigFileName(tokenList->getOrigFile(tok)), mFileName(tokenList->file(tok))
{
}
ErrorLogger::ErrorMessage::FileLocation::FileLocation(const Token* tok, const std::string &info, const TokenList* tokenList)
: fileIndex(tok->fileIndex()), line(tok->linenr()), col(tok->col()), mOrigFileName(tokenList->getOrigFile(tok)), mFileName(tokenList->file(tok)), mInfo(info)
{
}
std::string ErrorLogger::ErrorMessage::FileLocation::getfile(bool convert) const
{
if (convert)
return Path::toNativeSeparators(mFileName);
return mFileName;
}
std::string ErrorLogger::ErrorMessage::FileLocation::getOrigFile(bool convert) const
{
if (convert)
return Path::toNativeSeparators(mOrigFileName);
return mOrigFileName;
}
void ErrorLogger::ErrorMessage::FileLocation::setfile(const std::string &file)
{
mFileName = file;
mFileName = Path::fromNativeSeparators(mFileName);
mFileName = Path::simplifyPath(mFileName);
}
std::string ErrorLogger::ErrorMessage::FileLocation::stringify() const
{
std::ostringstream oss;
oss << '[' << Path::toNativeSeparators(mFileName);
if (line != Suppressions::Suppression::NO_LINE)
oss << ':' << line;
oss << ']';
return oss.str();
}
std::string ErrorLogger::toxml(const std::string &str)
{
std::ostringstream xml;
for (std::size_t i = 0U; i < str.length(); i++) {
const unsigned char c = str[i];
switch (c) {
case '<':
xml << "<";
break;
case '>':
xml << ">";
break;
case '&':
xml << "&";
break;
case '\"':
xml << """;
break;
case '\0':
xml << "\\0";
break;
default:
if (c >= ' ' && c <= 0x7f)
xml << c;
else
xml << 'x';
break;
}
}
return xml.str();
}
std::string ErrorLogger::plistHeader(const std::string &version, const std::vector &files)
{
std::ostringstream ostr;
ostr << "\r\n"
<< "\r\n"
<< "\r\n"
<< "\r\n"
<< " clang_version\r\n"
<< "cppcheck version " << version << "\r\n"
<< " files\r\n"
<< " \r\n";
for (unsigned int i = 0; i < files.size(); ++i)
ostr << " " << ErrorLogger::toxml(files[i]) << "\r\n";
ostr << " \r\n"
<< " diagnostics\r\n"
<< " \r\n";
return ostr.str();
}
static std::string plistLoc(const char indent[], const ErrorLogger::ErrorMessage::FileLocation &loc)
{
std::ostringstream ostr;
ostr << indent << "\r\n"
<< indent << ' ' << "line" << loc.line << "\r\n"
<< indent << ' ' << "col" << loc.col << "\r\n"
<< indent << ' ' << "file" << loc.fileIndex << "\r\n"
<< indent << "\r\n";
return ostr.str();
}
std::string ErrorLogger::plistData(const ErrorLogger::ErrorMessage &msg)
{
std::ostringstream plist;
plist << " \r\n"
<< " path\r\n"
<< " \r\n";
std::list::const_iterator prev = msg._callStack.begin();
for (std::list::const_iterator it = msg._callStack.begin(); it != msg._callStack.end(); ++it) {
if (prev != it) {
plist << " \r\n"
<< " kindcontrol\r\n"
<< " edges\r\n"
<< " \r\n"
<< " \r\n"
<< " start\r\n"
<< " \r\n"
<< plistLoc(" ", *prev)
<< plistLoc(" ", *prev)
<< " \r\n"
<< " end\r\n"
<< " \r\n"
<< plistLoc(" ", *it)
<< plistLoc(" ", *it)
<< " \r\n"
<< " \r\n"
<< " \r\n"
<< " \r\n";
prev = it;
}
std::list::const_iterator next = it;
++next;
const std::string message = (it->getinfo().empty() && next == msg._callStack.end() ? msg.shortMessage() : it->getinfo());
plist << " \r\n"
<< " kindevent\r\n"
<< " location\r\n"
<< plistLoc(" ", *it)
<< " ranges\r\n"
<< " \r\n"
<< " \r\n"
<< plistLoc(" ", *it)
<< plistLoc(" ", *it)
<< " \r\n"
<< " \r\n"
<< " depth0\r\n"
<< " extended_message\r\n"
<< " " << ErrorLogger::toxml(message) << "\r\n"
<< " message\r\n"
<< " " << ErrorLogger::toxml(message) << "\r\n"
<< " \r\n";
}
plist << " \r\n"
<< " description" << ErrorLogger::toxml(msg.shortMessage()) << "\r\n"
<< " category" << Severity::toString(msg._severity) << "\r\n"
<< " type" << ErrorLogger::toxml(msg.shortMessage()) << "\r\n"
<< " check_name" << msg._id << "\r\n"
<< " \r\n"
<< " issue_hash_content_of_line_in_context" << 0 << "\r\n"
<< " issue_context_kind\r\n"
<< " issue_context\r\n"
<< " issue_hash_function_offset\r\n"
<< " location\r\n"
<< plistLoc(" ", msg._callStack.back())
<< " \r\n";
return plist.str();
}
std::string replaceStr(std::string s, const std::string &from, const std::string &to)
{
std::string::size_type pos1 = 0;
while (pos1 < s.size()) {
pos1 = s.find(from, pos1);
if (pos1 == std::string::npos)
return s;
if (pos1 > 0 && (s[pos1-1] == '_' || std::isalnum(s[pos1-1]))) {
pos1++;
continue;
}
const std::string::size_type pos2 = pos1 + from.size();
if (pos2 >= s.size())
return s.substr(0,pos1) + to;
if (s[pos2] == '_' || std::isalnum(s[pos2])) {
pos1++;
continue;
}
s = s.substr(0,pos1) + to + s.substr(pos2);
pos1 += to.size();
}
return s;
}