/
base.rs
558 lines (503 loc) · 18.9 KB
/
base.rs
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use ast;
use ast::Name;
use codemap;
use codemap::{CodeMap, Span, ExpnInfo};
use ext;
use ext::expand;
use parse;
use parse::token;
use parse::token::{InternedString, intern, str_to_ident};
use util::small_vector::SmallVector;
use std::hashmap::HashMap;
// new-style macro! tt code:
//
// MacResult, NormalTT, IdentTT
//
// also note that ast::Mac used to have a bunch of extraneous cases and
// is now probably a redundant AST node, can be merged with
// ast::MacInvocTT.
pub struct MacroDef {
name: ~str,
ext: SyntaxExtension
}
pub type ItemDecorator =
fn(&mut ExtCtxt, Span, @ast::MetaItem, @ast::Item, |@ast::Item|);
pub struct BasicMacroExpander {
expander: MacroExpanderFn,
span: Option<Span>
}
pub trait MacroExpander {
fn expand(&self,
ecx: &mut ExtCtxt,
span: Span,
token_tree: &[ast::TokenTree])
-> MacResult;
}
pub type MacroExpanderFn =
fn(ecx: &mut ExtCtxt, span: codemap::Span, token_tree: &[ast::TokenTree])
-> MacResult;
impl MacroExpander for BasicMacroExpander {
fn expand(&self,
ecx: &mut ExtCtxt,
span: Span,
token_tree: &[ast::TokenTree])
-> MacResult {
(self.expander)(ecx, span, token_tree)
}
}
pub struct BasicIdentMacroExpander {
expander: IdentMacroExpanderFn,
span: Option<Span>
}
pub trait IdentMacroExpander {
fn expand(&self,
cx: &mut ExtCtxt,
sp: Span,
ident: ast::Ident,
token_tree: ~[ast::TokenTree])
-> MacResult;
}
impl IdentMacroExpander for BasicIdentMacroExpander {
fn expand(&self,
cx: &mut ExtCtxt,
sp: Span,
ident: ast::Ident,
token_tree: ~[ast::TokenTree])
-> MacResult {
(self.expander)(cx, sp, ident, token_tree)
}
}
pub type IdentMacroExpanderFn =
fn(&mut ExtCtxt, Span, ast::Ident, ~[ast::TokenTree]) -> MacResult;
pub type MacroCrateRegistrationFun =
fn(|ast::Name, SyntaxExtension|);
pub trait AnyMacro {
fn make_expr(&self) -> @ast::Expr;
fn make_items(&self) -> SmallVector<@ast::Item>;
fn make_stmt(&self) -> @ast::Stmt;
}
pub enum MacResult {
MRExpr(@ast::Expr),
MRItem(@ast::Item),
MRAny(~AnyMacro:),
MRDef(MacroDef),
}
impl MacResult {
/// Create an empty expression MacResult; useful for satisfying
/// type signatures after emitting a non-fatal error (which stop
/// compilation well before the validity (or otherwise)) of the
/// expression are checked.
pub fn raw_dummy_expr(sp: codemap::Span) -> @ast::Expr {
@ast::Expr {
id: ast::DUMMY_NODE_ID,
node: ast::ExprLogLevel,
span: sp
}
}
pub fn dummy_expr(sp: codemap::Span) -> MacResult {
MRExpr(MacResult::raw_dummy_expr(sp))
}
}
pub enum SyntaxExtension {
// #[deriving] and such
ItemDecorator(ItemDecorator),
// Token-tree expanders
NormalTT(~MacroExpander:'static, Option<Span>),
// An IdentTT is a macro that has an
// identifier in between the name of the
// macro and the argument. Currently,
// the only examples of this is
// macro_rules!
// perhaps macro_rules! will lose its odd special identifier argument,
// and this can go away also
IdentTT(~IdentMacroExpander:'static, Option<Span>),
}
pub struct BlockInfo {
// should macros escape from this scope?
macros_escape : bool,
// what are the pending renames?
pending_renames : RenameList,
}
impl BlockInfo {
pub fn new() -> BlockInfo {
BlockInfo {
macros_escape: false,
pending_renames: ~[],
}
}
}
// a list of ident->name renamings
pub type RenameList = ~[(ast::Ident,Name)];
// The base map of methods for expanding syntax extension
// AST nodes into full ASTs
pub fn syntax_expander_table() -> SyntaxEnv {
// utility function to simplify creating NormalTT syntax extensions
fn builtin_normal_expander(f: MacroExpanderFn) -> SyntaxExtension {
NormalTT(~BasicMacroExpander {
expander: f,
span: None,
},
None)
}
let mut syntax_expanders = SyntaxEnv::new();
syntax_expanders.insert(intern(&"macro_rules"),
IdentTT(~BasicIdentMacroExpander {
expander: ext::tt::macro_rules::add_new_extension,
span: None,
},
None));
syntax_expanders.insert(intern(&"fmt"),
builtin_normal_expander(
ext::fmt::expand_syntax_ext));
syntax_expanders.insert(intern(&"format_args"),
builtin_normal_expander(
ext::format::expand_args));
syntax_expanders.insert(intern(&"env"),
builtin_normal_expander(
ext::env::expand_env));
syntax_expanders.insert(intern(&"option_env"),
builtin_normal_expander(
ext::env::expand_option_env));
syntax_expanders.insert(intern("bytes"),
builtin_normal_expander(
ext::bytes::expand_syntax_ext));
syntax_expanders.insert(intern("concat_idents"),
builtin_normal_expander(
ext::concat_idents::expand_syntax_ext));
syntax_expanders.insert(intern("concat"),
builtin_normal_expander(
ext::concat::expand_syntax_ext));
syntax_expanders.insert(intern(&"log_syntax"),
builtin_normal_expander(
ext::log_syntax::expand_syntax_ext));
syntax_expanders.insert(intern(&"deriving"),
ItemDecorator(ext::deriving::expand_meta_deriving));
// Quasi-quoting expanders
syntax_expanders.insert(intern(&"quote_tokens"),
builtin_normal_expander(
ext::quote::expand_quote_tokens));
syntax_expanders.insert(intern(&"quote_expr"),
builtin_normal_expander(
ext::quote::expand_quote_expr));
syntax_expanders.insert(intern(&"quote_ty"),
builtin_normal_expander(
ext::quote::expand_quote_ty));
syntax_expanders.insert(intern(&"quote_item"),
builtin_normal_expander(
ext::quote::expand_quote_item));
syntax_expanders.insert(intern(&"quote_pat"),
builtin_normal_expander(
ext::quote::expand_quote_pat));
syntax_expanders.insert(intern(&"quote_stmt"),
builtin_normal_expander(
ext::quote::expand_quote_stmt));
syntax_expanders.insert(intern(&"line"),
builtin_normal_expander(
ext::source_util::expand_line));
syntax_expanders.insert(intern(&"col"),
builtin_normal_expander(
ext::source_util::expand_col));
syntax_expanders.insert(intern(&"file"),
builtin_normal_expander(
ext::source_util::expand_file));
syntax_expanders.insert(intern(&"stringify"),
builtin_normal_expander(
ext::source_util::expand_stringify));
syntax_expanders.insert(intern(&"include"),
builtin_normal_expander(
ext::source_util::expand_include));
syntax_expanders.insert(intern(&"include_str"),
builtin_normal_expander(
ext::source_util::expand_include_str));
syntax_expanders.insert(intern(&"include_bin"),
builtin_normal_expander(
ext::source_util::expand_include_bin));
syntax_expanders.insert(intern(&"module_path"),
builtin_normal_expander(
ext::source_util::expand_mod));
syntax_expanders.insert(intern(&"asm"),
builtin_normal_expander(
ext::asm::expand_asm));
syntax_expanders.insert(intern(&"cfg"),
builtin_normal_expander(
ext::cfg::expand_cfg));
syntax_expanders.insert(intern(&"trace_macros"),
builtin_normal_expander(
ext::trace_macros::expand_trace_macros));
syntax_expanders
}
pub struct MacroCrate {
lib: Option<Path>,
cnum: ast::CrateNum,
}
pub trait CrateLoader {
fn load_crate(&mut self, krate: &ast::ViewItem) -> MacroCrate;
fn get_exported_macros(&mut self, crate_num: ast::CrateNum) -> ~[~str];
fn get_registrar_symbol(&mut self, crate_num: ast::CrateNum) -> Option<~str>;
}
// One of these is made during expansion and incrementally updated as we go;
// when a macro expansion occurs, the resulting nodes have the backtrace()
// -> expn_info of their expansion context stored into their span.
pub struct ExtCtxt<'a> {
parse_sess: @parse::ParseSess,
cfg: ast::CrateConfig,
backtrace: Option<@ExpnInfo>,
loader: &'a mut CrateLoader,
mod_path: ~[ast::Ident],
trace_mac: bool
}
impl<'a> ExtCtxt<'a> {
pub fn new<'a>(parse_sess: @parse::ParseSess, cfg: ast::CrateConfig,
loader: &'a mut CrateLoader) -> ExtCtxt<'a> {
ExtCtxt {
parse_sess: parse_sess,
cfg: cfg,
backtrace: None,
loader: loader,
mod_path: ~[],
trace_mac: false
}
}
pub fn expand_expr(&mut self, mut e: @ast::Expr) -> @ast::Expr {
loop {
match e.node {
ast::ExprMac(..) => {
let mut expander = expand::MacroExpander {
extsbox: syntax_expander_table(),
cx: self,
};
e = expand::expand_expr(e, &mut expander);
}
_ => return e
}
}
}
pub fn codemap(&self) -> @CodeMap { self.parse_sess.cm }
pub fn parse_sess(&self) -> @parse::ParseSess { self.parse_sess }
pub fn cfg(&self) -> ast::CrateConfig { self.cfg.clone() }
pub fn call_site(&self) -> Span {
match self.backtrace {
Some(expn_info) => expn_info.call_site,
None => self.bug("missing top span")
}
}
pub fn print_backtrace(&self) { }
pub fn backtrace(&self) -> Option<@ExpnInfo> { self.backtrace }
pub fn mod_push(&mut self, i: ast::Ident) { self.mod_path.push(i); }
pub fn mod_pop(&mut self) { self.mod_path.pop().unwrap(); }
pub fn mod_path(&self) -> ~[ast::Ident] { self.mod_path.clone() }
pub fn bt_push(&mut self, ei: codemap::ExpnInfo) {
match ei {
ExpnInfo {call_site: cs, callee: ref callee} => {
self.backtrace =
Some(@ExpnInfo {
call_site: Span {lo: cs.lo, hi: cs.hi,
expn_info: self.backtrace},
callee: (*callee).clone()
});
}
}
}
pub fn bt_pop(&mut self) {
match self.backtrace {
Some(expn_info) => self.backtrace = expn_info.call_site.expn_info,
_ => self.bug("tried to pop without a push")
}
}
/// Emit `msg` attached to `sp`, and stop compilation immediately.
///
/// `span_err` should be strongly prefered where-ever possible:
/// this should *only* be used when
/// - continuing has a high risk of flow-on errors (e.g. errors in
/// declaring a macro would cause all uses of that macro to
/// complain about "undefined macro"), or
/// - there is literally nothing else that can be done (however,
/// in most cases one can construct a dummy expression/item to
/// substitute; we never hit resolve/type-checking so the dummy
/// value doesn't have to match anything)
pub fn span_fatal(&self, sp: Span, msg: &str) -> ! {
self.print_backtrace();
self.parse_sess.span_diagnostic.span_fatal(sp, msg);
}
/// Emit `msg` attached to `sp`, without immediately stopping
/// compilation.
///
/// Compilation will be stopped in the near future (at the end of
/// the macro expansion phase).
pub fn span_err(&self, sp: Span, msg: &str) {
self.print_backtrace();
self.parse_sess.span_diagnostic.span_err(sp, msg);
}
pub fn span_warn(&self, sp: Span, msg: &str) {
self.print_backtrace();
self.parse_sess.span_diagnostic.span_warn(sp, msg);
}
pub fn span_unimpl(&self, sp: Span, msg: &str) -> ! {
self.print_backtrace();
self.parse_sess.span_diagnostic.span_unimpl(sp, msg);
}
pub fn span_bug(&self, sp: Span, msg: &str) -> ! {
self.print_backtrace();
self.parse_sess.span_diagnostic.span_bug(sp, msg);
}
pub fn span_note(&self, sp: Span, msg: &str) {
self.print_backtrace();
self.parse_sess.span_diagnostic.span_note(sp, msg);
}
pub fn bug(&self, msg: &str) -> ! {
self.print_backtrace();
self.parse_sess.span_diagnostic.handler().bug(msg);
}
pub fn trace_macros(&self) -> bool {
self.trace_mac
}
pub fn set_trace_macros(&mut self, x: bool) {
self.trace_mac = x
}
pub fn ident_of(&self, st: &str) -> ast::Ident {
str_to_ident(st)
}
}
/// Extract a string literal from `expr`, emitting `err_msg` if `expr`
/// is not a string literal. This does not stop compilation on error,
/// merely emits a non-fatal error and returns None.
pub fn expr_to_str(cx: &ExtCtxt, expr: @ast::Expr, err_msg: &str)
-> Option<(InternedString, ast::StrStyle)> {
match expr.node {
ast::ExprLit(l) => match l.node {
ast::LitStr(ref s, style) => return Some(((*s).clone(), style)),
_ => cx.span_err(l.span, err_msg)
},
_ => cx.span_err(expr.span, err_msg)
}
None
}
/// Non-fatally assert that `tts` is empty. Note that this function
/// returns even when `tts` is non-empty, macros that *need* to stop
/// compilation should call
/// `cx.parse_sess.span_diagnostic.abort_if_errors()` (this should be
/// done as rarely as possible).
pub fn check_zero_tts(cx: &ExtCtxt,
sp: Span,
tts: &[ast::TokenTree],
name: &str) {
if tts.len() != 0 {
cx.span_err(sp, format!("{} takes no arguments", name));
}
}
/// Extract the string literal from the first token of `tts`. If this
/// is not a string literal, emit an error and return None.
pub fn get_single_str_from_tts(cx: &ExtCtxt,
sp: Span,
tts: &[ast::TokenTree],
name: &str)
-> Option<~str> {
if tts.len() != 1 {
cx.span_err(sp, format!("{} takes 1 argument.", name));
} else {
match tts[0] {
ast::TTTok(_, token::LIT_STR(ident))
| ast::TTTok(_, token::LIT_STR_RAW(ident, _)) => {
return Some(token::get_ident(ident).get().to_str())
}
_ => cx.span_err(sp, format!("{} requires a string.", name)),
}
}
None
}
/// Extract comma-separated expressions from `tts`. If there is a
/// parsing error, emit a non-fatal error and return None.
pub fn get_exprs_from_tts(cx: &ExtCtxt,
sp: Span,
tts: &[ast::TokenTree]) -> Option<~[@ast::Expr]> {
let mut p = parse::new_parser_from_tts(cx.parse_sess(),
cx.cfg(),
tts.to_owned());
let mut es = ~[];
while p.token != token::EOF {
if es.len() != 0 && !p.eat(&token::COMMA) {
cx.span_err(sp, "expected token: `,`");
return None;
}
es.push(p.parse_expr());
}
Some(es)
}
// in order to have some notion of scoping for macros,
// we want to implement the notion of a transformation
// environment.
// This environment maps Names to SyntaxExtensions.
// Actually, the following implementation is parameterized
// by both key and value types.
//impl question: how to implement it? Initially, the
// env will contain only macros, so it might be painful
// to add an empty frame for every context. Let's just
// get it working, first....
// NB! the mutability of the underlying maps means that
// if expansion is out-of-order, a deeper scope may be
// able to refer to a macro that was added to an enclosing
// scope lexically later than the deeper scope.
struct MapChainFrame {
info: BlockInfo,
map: HashMap<Name, SyntaxExtension>,
}
#[unsafe_destructor]
impl Drop for MapChainFrame {
fn drop(&mut self) {
// make sure that syntax extension dtors run before we drop the libs
self.map.clear();
}
}
// Only generic to make it easy to test
pub struct SyntaxEnv {
priv chain: ~[MapChainFrame],
}
impl SyntaxEnv {
pub fn new() -> SyntaxEnv {
let mut map = SyntaxEnv { chain: ~[] };
map.push_frame();
map
}
pub fn push_frame(&mut self) {
self.chain.push(MapChainFrame {
info: BlockInfo::new(),
map: HashMap::new(),
});
}
pub fn pop_frame(&mut self) {
assert!(self.chain.len() > 1, "too many pops on MapChain!");
self.chain.pop();
}
fn find_escape_frame<'a>(&'a mut self) -> &'a mut MapChainFrame {
for (i, frame) in self.chain.mut_iter().enumerate().rev() {
if !frame.info.macros_escape || i == 0 {
return frame
}
}
unreachable!()
}
pub fn find<'a>(&'a self, k: &Name) -> Option<&'a SyntaxExtension> {
for frame in self.chain.iter().rev() {
match frame.map.find(k) {
Some(v) => return Some(v),
None => {}
}
}
None
}
pub fn insert(&mut self, k: Name, v: SyntaxExtension) {
self.find_escape_frame().map.insert(k, v);
}
pub fn info<'a>(&'a mut self) -> &'a mut BlockInfo {
&mut self.chain[self.chain.len()-1].info
}
}