2012-05-18 10:05:24 -07:00

208 lines
6.9 KiB
Rust

import std::map::hashmap;
import parse::parser;
import diagnostic::span_handler;
import codemap::{codemap, span, expn_info, expanded_from};
import std::map::str_hash;
type syntax_expander_ =
fn@(ext_ctxt, span, ast::mac_arg, ast::mac_body) -> @ast::expr;
type syntax_expander = {
expander: syntax_expander_,
span: option<span>};
type macro_def = {ident: str, ext: syntax_extension};
type macro_definer =
fn@(ext_ctxt, span, ast::mac_arg, ast::mac_body) -> macro_def;
type item_decorator =
fn@(ext_ctxt, span, ast::meta_item, [@ast::item]) -> [@ast::item];
enum syntax_extension {
normal(syntax_expander),
macro_defining(macro_definer),
item_decorator(item_decorator),
}
// A temporary hard-coded map of methods for expanding syntax extension
// AST nodes into full ASTs
fn syntax_expander_table() -> hashmap<str, syntax_extension> {
fn builtin(f: syntax_expander_) -> syntax_extension
{normal({expander: f, span: none})}
let syntax_expanders = str_hash::<syntax_extension>();
syntax_expanders.insert("fmt", builtin(ext::fmt::expand_syntax_ext));
syntax_expanders.insert("auto_serialize",
item_decorator(ext::auto_serialize::expand));
syntax_expanders.insert("env", builtin(ext::env::expand_syntax_ext));
syntax_expanders.insert("include_str",
builtin(ext::include::str::expand_syntax_ext));
syntax_expanders.insert("macro",
macro_defining(ext::simplext::add_new_extension));
syntax_expanders.insert("concat_idents",
builtin(ext::concat_idents::expand_syntax_ext));
syntax_expanders.insert("ident_to_str",
builtin(ext::ident_to_str::expand_syntax_ext));
syntax_expanders.insert("log_syntax",
builtin(ext::log_syntax::expand_syntax_ext));
syntax_expanders.insert("ast",
builtin(ext::qquote::expand_ast));
ret syntax_expanders;
}
iface ext_ctxt {
fn codemap() -> codemap;
fn parse_sess() -> parse::parse_sess;
fn cfg() -> ast::crate_cfg;
fn print_backtrace();
fn backtrace() -> expn_info;
fn bt_push(ei: codemap::expn_info_);
fn bt_pop();
fn span_fatal(sp: span, msg: str) -> !;
fn span_err(sp: span, msg: str);
fn span_unimpl(sp: span, msg: str) -> !;
fn span_bug(sp: span, msg: str) -> !;
fn bug(msg: str) -> !;
fn next_id() -> ast::node_id;
}
fn mk_ctxt(parse_sess: parse::parse_sess,
cfg: ast::crate_cfg) -> ext_ctxt {
type ctxt_repr = {parse_sess: parse::parse_sess,
cfg: ast::crate_cfg,
mut backtrace: expn_info};
impl of ext_ctxt for ctxt_repr {
fn codemap() -> codemap { self.parse_sess.cm }
fn parse_sess() -> parse::parse_sess { self.parse_sess }
fn cfg() -> ast::crate_cfg { self.cfg }
fn print_backtrace() { }
fn backtrace() -> expn_info { self.backtrace }
fn bt_push(ei: codemap::expn_info_) {
alt ei {
expanded_from({call_site: cs, callie: callie}) {
self.backtrace =
some(@expanded_from({
call_site: {lo: cs.lo, hi: cs.hi,
expn_info: self.backtrace},
callie: callie}));
}
}
}
fn bt_pop() {
alt self.backtrace {
some(@expanded_from({call_site: {expn_info: prev, _}, _})) {
self.backtrace = prev
}
_ { self.bug("tried to pop without a push"); }
}
}
fn span_fatal(sp: span, msg: str) -> ! {
self.print_backtrace();
self.parse_sess.span_diagnostic.span_fatal(sp, msg);
}
fn span_err(sp: span, msg: str) {
self.print_backtrace();
self.parse_sess.span_diagnostic.span_err(sp, msg);
}
fn span_unimpl(sp: span, msg: str) -> ! {
self.print_backtrace();
self.parse_sess.span_diagnostic.span_unimpl(sp, msg);
}
fn span_bug(sp: span, msg: str) -> ! {
self.print_backtrace();
self.parse_sess.span_diagnostic.span_bug(sp, msg);
}
fn bug(msg: str) -> ! {
self.print_backtrace();
self.parse_sess.span_diagnostic.handler().bug(msg);
}
fn next_id() -> ast::node_id {
ret parse::next_node_id(self.parse_sess);
}
}
let imp : ctxt_repr = {
parse_sess: parse_sess,
cfg: cfg,
mut backtrace: none
};
ret imp as ext_ctxt
}
fn expr_to_str(cx: ext_ctxt, expr: @ast::expr, error: str) -> str {
alt expr.node {
ast::expr_lit(l) {
alt l.node {
ast::lit_str(s) { ret s; }
_ { cx.span_fatal(l.span, error); }
}
}
_ { cx.span_fatal(expr.span, error); }
}
}
fn expr_to_ident(cx: ext_ctxt, expr: @ast::expr, error: str) -> ast::ident {
alt expr.node {
ast::expr_path(p) {
if vec::len(p.types) > 0u || vec::len(p.idents) != 1u {
cx.span_fatal(expr.span, error);
} else { ret p.idents[0]; }
}
_ { cx.span_fatal(expr.span, error); }
}
}
fn make_new_lit(cx: ext_ctxt, sp: codemap::span, lit: ast::lit_) ->
@ast::expr {
let sp_lit = @{node: lit, span: sp};
ret @{id: cx.next_id(), node: ast::expr_lit(sp_lit), span: sp};
}
fn get_mac_args_no_max(cx: ext_ctxt, sp: span, arg: ast::mac_arg,
min: uint, name: str) -> [@ast::expr] {
ret get_mac_args(cx, sp, arg, min, none, name);
}
fn get_mac_args(cx: ext_ctxt, sp: span, arg: ast::mac_arg,
min: uint, max: option<uint>, name: str) -> [@ast::expr] {
alt arg {
some(expr) {
alt expr.node {
ast::expr_vec(elts, _) {
let elts_len = vec::len(elts);
alt max {
some(max) if ! (min <= elts_len && elts_len <= max) {
cx.span_fatal(sp,
#fmt["#%s takes between %u and %u arguments.",
name, min, max]);
}
none if ! (min <= elts_len) {
cx.span_fatal(sp, #fmt["#%s needs at least %u arguments.",
name, min]);
}
_ { ret elts; /* we're good */}
}
}
_ {
cx.span_fatal(sp, #fmt["#%s: malformed invocation", name])
}
}
}
none {cx.span_fatal(sp, #fmt["#%s: missing arguments", name])}
}
}
fn get_mac_body(cx: ext_ctxt, sp: span, args: ast::mac_body)
-> ast::mac_body_
{
alt (args) {
some(body) {body}
none {cx.span_fatal(sp, "missing macro body")}
}
}
//
// Local Variables:
// mode: rust
// fill-column: 78;
// indent-tabs-mode: nil
// c-basic-offset: 4
// buffer-file-coding-system: utf-8-unix
// End:
//