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// file : build/parser.cxx -*- C++ -*-
// copyright : Copyright (c) 2014-2015 Code Synthesis Tools CC
// license : MIT; see accompanying LICENSE file
#include <build/parser>
#include <iostream>
#include <build/token>
#include <build/lexer>
using namespace std;
namespace build
{
// Output the token type and value in a format suitable for diagnostics.
//
ostream&
operator<< (ostream&, const token&);
typedef token_type type;
void parser::
parse (istream& is, const path& p)
{
lexer l (is, p.string (), diag_);
lexer_ = &l;
path_ = &p;
token t (type::eos, 0, 0);
type tt;
next (t, tt);
parse_clause (t, tt);
if (tt != type::eos)
{
error (t) << "unexpected " << t << endl;
throw parser_error ();
}
}
void parser::
parse_clause (token& t, token_type& tt)
{
while (tt != type::eos)
{
// We always start with one or more names.
//
if (tt != type::name && tt != type::lcbrace)
break; // Something else. Let our caller handle that.
names ns (parse_names (t, tt));
if (tt == type::colon)
{
next (t, tt);
// Dependency declaration.
//
if (tt == type::name || tt == type::lcbrace)
{
names ns (parse_names (t, tt));
if (tt == type::newline)
next (t, tt);
else if (tt != type::eos)
{
error (t) << "expected newline instead of " << t << endl;
throw parser_error ();
}
continue;
}
if (tt == type::newline)
{
// See if we have a directory/target scope.
//
if (next (t, tt) == type::lcbrace)
{
// Should be on its own line.
//
if (next (t, tt) != type::newline)
{
error (t) << "expected newline after '{'" << endl;
throw parser_error ();
}
// See if this is a directory or target scope. Different
// things can appear inside depending on which it is.
//
bool dir (false);
for (const auto& n: ns)
{
if (n.back () == '/')
{
if (ns.size () != 1)
{
// @@ TODO: point to name.
//
error (t) << "multiple names in directory scope" << endl;
throw parser_error ();
}
dir = true;
}
}
next (t, tt);
if (dir)
// A directory scope can contain anything that a top level can.
//
parse_clause (t, tt);
else
{
// @@ TODO: target scope.
}
if (tt != type::rcbrace)
{
error (t) << "expected '}' instead of " << t << endl;
throw parser_error ();
}
// Should be on its own line.
//
if (next (t, tt) == type::newline)
next (t, tt);
else if (tt != type::eos)
{
error (t) << "expected newline after '}'" << endl;
throw parser_error ();
}
}
continue;
}
if (tt == type::eos)
continue;
error (t) << "expected newline insetad of " << t << endl;
throw parser_error ();
}
error (t) << "unexpected " << t << endl;
throw parser_error ();
}
}
void parser::
parse_names (token& t, type& tt, names& ns)
{
for (bool first (true);; first = false)
{
// Untyped name group, e.g., '{foo bar}'.
//
if (tt == type::lcbrace)
{
next (t, tt);
parse_names (t, tt, ns);
if (tt != type::rcbrace)
{
error (t) << "expected '}' instead of " << t << endl;
throw parser_error ();
}
next (t, tt);
continue;
}
// Name.
//
if (tt == type::name)
{
string name (t.name ());
// See if this is a type name, that is, it is followed by '{'.
//
if (next (t, tt) == type::lcbrace)
{
//cout << "type: " << name << endl;
//@@ TODO:
//
// - detect nested typed name groups, e.g., 'cxx{hxx{foo}}'.
//
next (t, tt);
parse_names (t, tt, ns);
if (tt != type::rcbrace)
{
error (t) << "expected '}' instead of " << t << endl;
throw parser_error ();
}
next (t, tt);
continue;
}
// This is a target, directory, or variable name.
//cout << "name: " << name << endl;
ns.push_back (name);
continue;
}
if (!first)
break;
error (t) << "expected name instead of " << t << endl;
throw parser_error ();
}
}
token_type parser::
next (token& t, token_type& tt)
{
t = lexer_->next ();
tt = t.type ();
return tt;
}
ostream& parser::
error (const token& t)
{
return diag_ << path_->string () << ':' << t.line () << ':' <<
t.column () << ": error: ";
}
// Output the token type and value in a format suitable for diagnostics.
//
ostream&
operator<< (ostream& os, const token& t)
{
switch (t.type ())
{
case token_type::eos: os << "<end-of-stream>"; break;
case token_type::newline: os << "<newline>"; break;
case token_type::colon: os << "':'"; break;
case token_type::lcbrace: os << "'{'"; break;
case token_type::rcbrace: os << "'}'"; break;
case token_type::name: os << '\'' << t.name () << '\''; break;
}
return os;
}
}
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