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Implement function-like procedural macros ( #[proc_macro])
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10 files changed

+213
-10
lines changed

10 files changed

+213
-10
lines changed

‎src/libproc_macro/lib.rs‎

Lines changed: 4 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -125,6 +125,10 @@ pub mod __internal {
125125
fn register_attr_proc_macro(&mut self,
126126
name: &str,
127127
expand: fn(TokenStream, TokenStream) -> TokenStream);
128+
129+
fn register_bang_proc_macro(&mut self,
130+
name: &str,
131+
expand: fn(TokenStream) -> TokenStream);
128132
}
129133

130134
// Emulate scoped_thread_local!() here essentially

‎src/librustc_metadata/creader.rs‎

Lines changed: 10 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -586,7 +586,7 @@ impl<'a> CrateLoader<'a> {
586586
use proc_macro::__internal::Registry;
587587
use rustc_back::dynamic_lib::DynamicLibrary;
588588
use syntax_ext::deriving::custom::ProcMacroDerive;
589-
use syntax_ext::proc_macro_impl::AttrProcMacro;
589+
use syntax_ext::proc_macro_impl::{AttrProcMacro, BangProcMacro};
590590

591591
let path = match dylib {
592592
Some(dylib) => dylib,
@@ -630,6 +630,15 @@ impl<'a> CrateLoader<'a> {
630630
);
631631
self.0.push((Symbol::intern(name), Rc::new(expand)));
632632
}
633+
634+
fn register_bang_proc_macro(&mut self,
635+
name: &str,
636+
expand: fn(TokenStream) -> TokenStream) {
637+
let expand = SyntaxExtension::ProcMacro(
638+
Box::new(BangProcMacro { inner: expand })
639+
);
640+
self.0.push((Symbol::intern(name), Rc::new(expand)));
641+
}
633642
}
634643

635644
let mut my_registrar = MyRegistrar(Vec::new());

‎src/libsyntax/feature_gate.rs‎

Lines changed: 5 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -763,6 +763,11 @@ pub const BUILTIN_ATTRIBUTES: &'static [(&'static str, AttributeType, AttributeG
763763
"attribute proc macros are currently unstable",
764764
cfg_fn!(proc_macro))),
765765

766+
("proc_macro", Normal, Gated(Stability::Unstable,
767+
"proc_macro",
768+
"function-like proc macros are currently unstable",
769+
cfg_fn!(proc_macro))),
770+
766771
("rustc_derive_registrar", Normal, Gated(Stability::Unstable,
767772
"rustc_derive_registrar",
768773
"used internally by rustc",

‎src/libsyntax_ext/proc_macro_impl.rs‎

Lines changed: 35 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -56,3 +56,38 @@ impl base::AttrProcMacro for AttrProcMacro {
5656
}
5757
}
5858
}
59+
60+
pub struct BangProcMacro {
61+
pub inner: fn(TsShim) -> TsShim,
62+
}
63+
64+
impl base::ProcMacro for BangProcMacro {
65+
fn expand<'cx>(&self,
66+
ecx: &'cx mut ExtCtxt,
67+
span: Span,
68+
input: TokenStream)
69+
-> TokenStream {
70+
let input = __internal::token_stream_wrap(input);
71+
72+
let res = __internal::set_parse_sess(&ecx.parse_sess, || {
73+
panic::catch_unwind(panic::AssertUnwindSafe(|| (self.inner)(input)))
74+
});
75+
76+
match res {
77+
Ok(stream) => __internal::token_stream_inner(stream),
78+
Err(e) => {
79+
let msg = "proc macro panicked";
80+
let mut err = ecx.struct_span_fatal(span, msg);
81+
if let Some(s) = e.downcast_ref::<String>() {
82+
err.help(&format!("message: {}", s));
83+
}
84+
if let Some(s) = e.downcast_ref::<&'static str>() {
85+
err.help(&format!("message: {}", s));
86+
}
87+
88+
err.emit();
89+
panic!(FatalError);
90+
}
91+
}
92+
}
93+
}

‎src/libsyntax_ext/proc_macro_registrar.rs‎

Lines changed: 57 additions & 9 deletions
Original file line numberDiff line numberDiff line change
@@ -27,21 +27,25 @@ use syntax_pos::{Span, DUMMY_SP};
2727

2828
use deriving;
2929

30+
const PROC_MACRO_KINDS: [&'static str; 3] =
31+
["proc_macro_derive", "proc_macro_attribute", "proc_macro"];
32+
3033
struct ProcMacroDerive {
3134
trait_name: ast::Name,
3235
function_name: Ident,
3336
span: Span,
3437
attrs: Vec<ast::Name>,
3538
}
3639

37-
struct AttrProcMacro {
40+
struct ProcMacroDef {
3841
function_name: Ident,
3942
span: Span,
4043
}
4144

4245
struct CollectProcMacros<'a> {
4346
derives: Vec<ProcMacroDerive>,
44-
attr_macros: Vec<AttrProcMacro>,
47+
attr_macros: Vec<ProcMacroDef>,
48+
bang_macros: Vec<ProcMacroDef>,
4549
in_root: bool,
4650
handler: &'a errors::Handler,
4751
is_proc_macro_crate: bool,
@@ -58,17 +62,18 @@ pub fn modify(sess: &ParseSess,
5862
let ecfg = ExpansionConfig::default("proc_macro".to_string());
5963
let mut cx = ExtCtxt::new(sess, ecfg, resolver);
6064

61-
let (derives, attr_macros) = {
65+
let (derives, attr_macros, bang_macros) = {
6266
let mut collect = CollectProcMacros {
6367
derives: Vec::new(),
6468
attr_macros: Vec::new(),
69+
bang_macros: Vec::new(),
6570
in_root: true,
6671
handler: handler,
6772
is_proc_macro_crate: is_proc_macro_crate,
6873
is_test_crate: is_test_crate,
6974
};
7075
visit::walk_crate(&mut collect, &krate);
71-
(collect.derives, collect.attr_macros)
76+
(collect.derives, collect.attr_macros, collect.bang_macros)
7277
};
7378

7479
if !is_proc_macro_crate {
@@ -83,7 +88,7 @@ pub fn modify(sess: &ParseSess,
8388
return krate;
8489
}
8590

86-
krate.module.items.push(mk_registrar(&mut cx, &derives, &attr_macros));
91+
krate.module.items.push(mk_registrar(&mut cx, &derives, &attr_macros, &bang_macros));
8792

8893
if krate.exported_macros.len() > 0 {
8994
handler.err("cannot export macro_rules! macros from a `proc-macro` \
@@ -93,6 +98,10 @@ pub fn modify(sess: &ParseSess,
9398
return krate
9499
}
95100

101+
fn is_proc_macro_attr(attr: &ast::Attribute) -> bool {
102+
PROC_MACRO_KINDS.iter().any(|kind| attr.check_name(kind))
103+
}
104+
96105
impl<'a> CollectProcMacros<'a> {
97106
fn check_not_pub_in_root(&self, vis: &ast::Visibility, sp: Span) {
98107
if self.is_proc_macro_crate &&
@@ -196,12 +205,12 @@ impl<'a> CollectProcMacros<'a> {
196205
fn collect_attr_proc_macro(&mut self, item: &'a ast::Item, attr: &'a ast::Attribute) {
197206
if let Some(_) = attr.meta_item_list() {
198207
self.handler.span_err(attr.span, "`#[proc_macro_attribute]` attribute
199-
cannot contain any meta items");
208+
does not take any arguments");
200209
return;
201210
}
202211

203212
if self.in_root && item.vis == ast::Visibility::Public {
204-
self.attr_macros.push(AttrProcMacro {
213+
self.attr_macros.push(ProcMacroDef {
205214
span: item.span,
206215
function_name: item.ident,
207216
});
@@ -215,6 +224,29 @@ impl<'a> CollectProcMacros<'a> {
215224
self.handler.span_err(item.span, msg);
216225
}
217226
}
227+
228+
fn collect_bang_proc_macro(&mut self, item: &'a ast::Item, attr: &'a ast::Attribute) {
229+
if let Some(_) = attr.meta_item_list() {
230+
self.handler.span_err(attr.span, "`#[proc_macro]` attribute
231+
does not take any arguments");
232+
return;
233+
}
234+
235+
if self.in_root && item.vis == ast::Visibility::Public {
236+
self.bang_macros.push(ProcMacroDef {
237+
span: item.span,
238+
function_name: item.ident,
239+
});
240+
} else {
241+
let msg = if !self.in_root {
242+
"functions tagged with `#[proc_macro]` must \
243+
currently reside in the root of the crate"
244+
} else {
245+
"functions tagged with `#[proc_macro]` must be `pub`"
246+
};
247+
self.handler.span_err(item.span, msg);
248+
}
249+
}
218250
}
219251

220252
impl<'a> Visitor<'a> for CollectProcMacros<'a> {
@@ -232,7 +264,7 @@ impl<'a> Visitor<'a> for CollectProcMacros<'a> {
232264
let mut found_attr: Option<&'a ast::Attribute> = None;
233265

234266
for attr in &item.attrs {
235-
if attr.check_name("proc_macro_derive") || attr.check_name("proc_macro_attribute") {
267+
if is_proc_macro_attr(&attr) {
236268
if let Some(prev_attr) = found_attr {
237269
let msg = if attr.name() == prev_attr.name() {
238270
format!("Only one `#[{}]` attribute is allowed on any given function",
@@ -285,6 +317,8 @@ impl<'a> Visitor<'a> for CollectProcMacros<'a> {
285317
self.collect_custom_derive(item, attr);
286318
} else if attr.check_name("proc_macro_attribute") {
287319
self.collect_attr_proc_macro(item, attr);
320+
} else if attr.check_name("proc_macro") {
321+
self.collect_bang_proc_macro(item, attr);
288322
};
289323

290324
visit::walk_item(self, item);
@@ -320,7 +354,8 @@ impl<'a> Visitor<'a> for CollectProcMacros<'a> {
320354
// }
321355
fn mk_registrar(cx: &mut ExtCtxt,
322356
custom_derives: &[ProcMacroDerive],
323-
custom_attrs: &[AttrProcMacro]) -> P<ast::Item> {
357+
custom_attrs: &[ProcMacroDef],
358+
custom_macros: &[ProcMacroDef]) -> P<ast::Item> {
324359
let eid = cx.codemap().record_expansion(ExpnInfo {
325360
call_site: DUMMY_SP,
326361
callee: NameAndSpan {
@@ -342,6 +377,7 @@ fn mk_registrar(cx: &mut ExtCtxt,
342377
let registrar = Ident::from_str("registrar");
343378
let register_custom_derive = Ident::from_str("register_custom_derive");
344379
let register_attr_proc_macro = Ident::from_str("register_attr_proc_macro");
380+
let register_bang_proc_macro = Ident::from_str("register_bang_proc_macro");
345381

346382
let mut stmts = custom_derives.iter().map(|cd| {
347383
let path = cx.path_global(cd.span, vec![cd.function_name]);
@@ -371,6 +407,18 @@ fn mk_registrar(cx: &mut ExtCtxt,
371407
vec![registrar, name, cx.expr_path(path)]))
372408
}));
373409

410+
stmts.extend(custom_macros.iter().map(|cm| {
411+
let name = cx.expr_str(cm.span, cm.function_name.name);
412+
let path = cx.path_global(cm.span, vec![cm.function_name]);
413+
let registrar = cx.expr_ident(cm.span, registrar);
414+
415+
let ufcs_path = cx.path(span,
416+
vec![proc_macro, __internal, registry, register_bang_proc_macro]);
417+
418+
cx.stmt_expr(cx.expr_call(span, cx.expr_path(ufcs_path),
419+
vec![registrar, name, cx.expr_path(path)]))
420+
}));
421+
374422
let path = cx.path(span, vec![proc_macro, __internal, registry]);
375423
let registrar_path = cx.ty_path(path);
376424
let arg_ty = cx.ty_rptr(span, registrar_path, None, ast::Mutability::Mutable);

‎src/test/compile-fail-fulldeps/proc-macro/auxiliary/bang_proc_macro.rs‎

Lines changed: 23 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,23 @@
1+
// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
2+
// file at the top-level directory of this distribution and at
3+
// http://rust-lang.org/COPYRIGHT.
4+
//
5+
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6+
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7+
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8+
// option. This file may not be copied, modified, or distributed
9+
// except according to those terms.
10+
11+
// force-host
12+
// no-prefer-dynamic
13+
#![feature(proc_macro)]
14+
#![crate_type = "proc-macro"]
15+
16+
extern crate proc_macro;
17+
18+
use proc_macro::TokenStream;
19+
20+
#[proc_macro]
21+
pub fn bang_proc_macro(input: TokenStream) -> TokenStream {
22+
input
23+
}

‎src/test/compile-fail-fulldeps/proc-macro/macro-use-bang.rs‎

Lines changed: 21 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,21 @@
1+
// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
2+
// file at the top-level directory of this distribution and at
3+
// http://rust-lang.org/COPYRIGHT.
4+
//
5+
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6+
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7+
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8+
// option. This file may not be copied, modified, or distributed
9+
// except according to those terms.
10+
11+
// aux-build:bang_proc_macro.rs
12+
13+
#![feature(proc_macro)]
14+
15+
#[macro_use]
16+
extern crate bang_proc_macro;
17+
18+
fn main() {
19+
bang_proc_macro!(println!("Hello, world!"));
20+
//~^ ERROR: procedural macros cannot be imported with `#[macro_use]`
21+
}

‎src/test/compile-fail-fulldeps/proc-macro/resolve-error.rs‎

Lines changed: 12 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -11,6 +11,7 @@
1111
// aux-build:derive-foo.rs
1212
// aux-build:derive-clona.rs
1313
// aux-build:attr_proc_macro.rs
14+
// aux-build:bang_proc_macro.rs
1415

1516
#![feature(proc_macro)]
1617

@@ -19,13 +20,19 @@ extern crate derive_foo;
1920
#[macro_use]
2021
extern crate derive_clona;
2122
extern crate attr_proc_macro;
23+
extern crate bang_proc_macro;
2224

2325
use attr_proc_macro::attr_proc_macro;
26+
use bang_proc_macro::bang_proc_macro;
2427

2528
macro_rules! FooWithLongNam {
2629
() => {}
2730
}
2831

32+
macro_rules! attr_proc_mac {
33+
() => {}
34+
}
35+
2936
#[derive(FooWithLongNan)]
3037
//~^ ERROR cannot find derive macro `FooWithLongNan` in this scope
3138
//~^^ HELP did you mean `FooWithLongName`?
@@ -61,7 +68,12 @@ fn main() {
6168

6269
attr_proc_macra!();
6370
//~^ ERROR cannot find macro `attr_proc_macra!` in this scope
71+
//~^^ HELP did you mean `attr_proc_mac!`?
6472

6573
Dlona!();
6674
//~^ ERROR cannot find macro `Dlona!` in this scope
75+
76+
bang_proc_macrp!();
77+
//~^ ERROR cannot find macro `bang_proc_macrp!` in this scope
78+
//~^^ HELP did you mean `bang_proc_macro!`?
6779
}

‎src/test/run-pass-fulldeps/proc-macro/auxiliary/bang-macro.rs‎

Lines changed: 26 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,26 @@
1+
// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
2+
// file at the top-level directory of this distribution and at
3+
// http://rust-lang.org/COPYRIGHT.
4+
//
5+
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6+
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7+
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8+
// option. This file may not be copied, modified, or distributed
9+
// except according to those terms.
10+
11+
// no-prefer-dynamic
12+
#![feature(proc_macro)]
13+
#![crate_type = "proc-macro"]
14+
15+
extern crate proc_macro;
16+
17+
use proc_macro::TokenStream;
18+
19+
#[proc_macro]
20+
pub fn rewrite(input: TokenStream) -> TokenStream {
21+
let input = input.to_string();
22+
23+
assert_eq!(input, r#""Hello, world!""#);
24+
25+
r#""NOT Hello, world!""#.parse().unwrap()
26+
}

‎src/test/run-pass-fulldeps/proc-macro/bang-macro.rs‎

Lines changed: 20 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,20 @@
1+
// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
2+
// file at the top-level directory of this distribution and at
3+
// http://rust-lang.org/COPYRIGHT.
4+
//
5+
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6+
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7+
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8+
// option. This file may not be copied, modified, or distributed
9+
// except according to those terms.
10+
11+
// aux-build:bang-macro.rs
12+
13+
#![feature(proc_macro)]
14+
15+
extern crate bang_macro;
16+
use bang_macro::rewrite;
17+
18+
fn main() {
19+
assert_eq!(rewrite!("Hello, world!"), "NOT Hello, world!");
20+
}

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