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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;
typedef token_punctuation punc;
void parser::
parse (istream& is, const path& p)
{
lexer l (is, p.string (), diag_);
lexer_ = &l;
path_ = &p;
token t (0, 0); // eos
type tt;
for (next (t, tt); tt != type::eos; )
{
// We always start with one or more names.
//
names (t, tt);
if (t.is (punc::colon))
{
next (t, tt);
if (tt == type::name || t.is (punc::lcbrace))
names (t, tt);
if (t.is (punc::newline))
next (t, tt);
else if (tt != type::eos)
{
error (t) << "expected newline insetad of " << t << endl;
throw parser_error ();
}
continue;
}
error (t) << "unexpected " << t << endl;
throw parser_error ();
}
}
void parser::
names (token& t, type& tt)
{
for (bool first (true);; first = false)
{
// Untyped name group, e.g., '{foo bar}'.
//
if (t.is (punc::lcbrace))
{
next (t, tt);
names (t, tt);
if (!t.is (punc::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 '{'.
//
next (t, tt);
if (t.is (punc::lcbrace))
{
//cout << "type: " << name << endl;
//@@ TODO:
//
// - detect nested typed name groups, e.g., 'cxx{hxx{foo}}'.
//
next (t, tt);
names (t, tt);
if (!t.is (punc::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;
continue;
}
if (!first)
break;
error (t) << "expected name instead of " << t << endl;
throw parser_error ();
}
}
void parser::
next (token& t, token_type& tt)
{
t = lexer_->next ();
tt = t.type ();
}
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::punctuation:
{
switch (t.punctuation ())
{
case token_punctuation::newline: os << "<newline>"; break;
case token_punctuation::colon: os << "':'"; break;
case token_punctuation::lcbrace: os << "'{'"; break;
case token_punctuation::rcbrace: os << "'}'"; break;
}
break;
}
case token_type::name: os << '\'' << t.name () << '\''; break;
}
return os;
}
}
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