Subject: [Boost-bugs] [Boost C++ Libraries] #4512: [program_options]: wrong option_description returned by options_descriptions::find_nothrow
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2010-08-05 22:17:56
#4512: [program_options]: wrong option_description returned by
options_descriptions::find_nothrow
----------------------------------------------+-----------------------------
Reporter: Soren Soe <soren.soe@â¦> | Owner: vladimir_prus
Type: Bugs | Status: new
Milestone: Boost 1.44.0 | Component: program_options
Version: Boost 1.44.0 | Severity: Problem
Keywords: |
----------------------------------------------+-----------------------------
In 1.43 my code started failing when an option_description has two
options where option1 is "all" and option2 is "all-chroots".
I am using command_line_style::allow_guessing and at some point the
command_line_parser calls
options_description::find_nothrow("all",true,...) in
options_description.cpp
It turns out find_nothrow has changed since the earlier version (1.38)
which I am currently using. The old version immediately returned on a
full_match:
{{{
...
// If we have a full patch, and an approximate match,
// ignore approximate match instead of reporting error.
// Say, if we have options "all" and "all-chroots", then
// "--all" on the command line should select the first one,
// without ambiguity.
//
// For now, we don't check the situation when there are
// two full matches.
if (r == option_description::full_match)
{
return m_options[i].get();
}
...
}}}
But in 1.43, the loop that iterates {{{m_options}}} sets a variable
{{{found}}} to which ever match is found last, be that a full_match or
an approximate_match:
{{{
...
if (r == option_description::full_match)
{
full_matches.push_back(m_options[i]->key(name));
}
else
{
// FIXME: the use of 'key' here might not
// be the best approach.
approximate_matches.push_back(m_options[i]->key(name));
}
found = m_options[i];
...
}}}
Ultimately, the variable {{{found}}} is returned and in my case with
the partial match even though there really was a full match.
I propose the following implementation of find_nothrow(...). The error
checking is unchanged from 1.43 version, but a full_match, if any,
will be returned as expected.
{{{
const option_description*
options_description::find_nothrow(const std::string& name,
bool approx,
bool long_ignore_case,
bool short_ignore_case) const
{
int found = -1;
vector<string> approximate_matches;
vector<string> full_matches;
// We use linear search because matching specified option
// name with the declaraed option name need to take care about
// case sensitivity and trailing '*' and so we can't use simple map.
for(unsigned i = 0; i < m_options.size(); ++i)
{
option_description::match_result r =
m_options[i]->match(name, approx, long_ignore_case,
short_ignore_case);
if (r == option_description::no_match)
continue;
if (r == option_description::full_match)
{
full_matches.push_back(m_options[i]->key(name));
// Use this full match regardless of other matches found.
found = i;
}
else
{
// FIXME: the use of 'key' here might not
// be the best approach.
approximate_matches.push_back(m_options[i]->key(name));
// If this is the first match found the use it. If
// a later full match is found that will be used instead.
if (found == -1)
found = i;
}
}
if (full_matches.size() > 1)
boost::throw_exception(
ambiguous_option(name, full_matches));
if (full_matches.empty() && approximate_matches.size() > 1)
boost::throw_exception(
ambiguous_option(name, approximate_matches));
return found>=0
? m_options[found].get()
: 0;
}
}}}
I have attached my modified version of options_description.cpp
-- Ticket URL: <https://svn.boost.org/trac/boost/ticket/4512> Boost C++ Libraries <http://www.boost.org/> Boost provides free peer-reviewed portable C++ source libraries.
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