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Rollup merge of #38842 - abonander:proc_macro_attribute, r=jseyfried

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Implement `#[proc_macro_attribute]`

This implements `#[proc_macro_attribute]` as described in https://github.com/rust-lang/rfcs/pull/1566

The following major (hopefully non-breaking) changes are included:

* Refactor `proc_macro::TokenStream` to use `syntax::tokenstream::TokenStream`.
    * `proc_macro::tokenstream::TokenStream` no longer emits newlines between items, this can be trivially restored if desired
    * `proc_macro::TokenStream::from_str` does not try to parse an item anymore, moved to `impl MultiItemModifier for CustomDerive` with more informative error message

* Implement `#[proc_macro_attribute]`, which expects functions of the kind `fn(TokenStream, TokenStream) -> TokenStream`
    * Reactivated `#![feature(proc_macro)]` and gated `#[proc_macro_attribute]` under it
    * `#![feature(proc_macro)]` and `#![feature(custom_attribute)]` are mutually exclusive
    * adding `#![feature(proc_macro)]` makes the expansion pass assume that any attributes that are not built-in, or introduced by existing syntax extensions, are proc-macro attributes

* Fix `feature_gate::find_lang_feature_issue()` to not use `unwrap()`

    * This change wasn't necessary for this PR, but it helped debugging a problem where I was using the wrong feature string.

* Move "completed feature gate checking" pass to after "name resolution" pass

    * This was necessary for proper feature-gating of `#[proc_macro_attribute]` invocations when the `proc_macro` feature flag isn't set.

Prototype/Litmus Test: [Implementation](https://github.com/abonander/anterofit/blob/proc_macro/service-attr/src/lib.rs#L13) -- [Usage](https://github.com/abonander/anterofit/blob/proc_macro/service-attr/examples/post_service.rs#L35)
This commit is contained in:
Alex Crichton 2017-01-19 15:49:23 -08:00
commit d4d276faaf
24 changed files with 613 additions and 127 deletions
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73
src/libproc_macro/lib.rs
View file

@ -39,9 +39,9 @@ extern crate syntax;
use std::fmt;
use std::str::FromStr;
use syntax::ast;
use syntax::errors::DiagnosticBuilder;
use syntax::parse;
use syntax::ptr::P;
use syntax::tokenstream::TokenStream as TokenStream_;
/// The main type provided by this crate, representing an abstract stream of
/// tokens.
@ -54,7 +54,7 @@ use syntax::ptr::P;
/// time!
#[stable(feature = "proc_macro_lib", since = "1.15.0")]
pub struct TokenStream {
inner: Vec<P<ast::Item>>,
inner: TokenStream_,
}
/// Error returned from `TokenStream::from_str`.
@ -77,17 +77,41 @@ pub struct LexError {
#[doc(hidden)]
pub mod __internal {
use std::cell::Cell;
use std::rc::Rc;
use syntax::ast;
use syntax::ptr::P;
use syntax::parse::ParseSess;
use super::TokenStream;
use syntax::parse::{self, token, ParseSess};
use syntax::tokenstream::TokenStream as TokenStream_;
use super::{TokenStream, LexError};
pub fn new_token_stream(item: P<ast::Item>) -> TokenStream {
TokenStream { inner: vec![item] }
TokenStream { inner: TokenStream_::from_tokens(vec![
token::Interpolated(Rc::new(token::NtItem(item)))
])}
}
pub fn token_stream_items(stream: TokenStream) -> Vec<P<ast::Item>> {
pub fn token_stream_wrap(inner: TokenStream_) -> TokenStream {
TokenStream {
inner: inner
}
}
pub fn token_stream_parse_items(stream: TokenStream) -> Result<Vec<P<ast::Item>>, LexError> {
with_parse_sess(move |sess| {
let mut parser = parse::new_parser_from_ts(sess, stream.inner);
let mut items = Vec::new();
while let Some(item) = try!(parser.parse_item().map_err(super::parse_to_lex_err)) {
items.push(item)
}
Ok(items)
})
}
pub fn token_stream_inner(stream: TokenStream) -> TokenStream_ {
stream.inner
}
@ -96,6 +120,10 @@ pub mod __internal {
trait_name: &str,
expand: fn(TokenStream) -> TokenStream,
attributes: &[&'static str]);
fn register_attr_proc_macro(&mut self,
name: &str,
expand: fn(TokenStream, TokenStream) -> TokenStream);
}
// Emulate scoped_thread_local!() here essentially
@ -125,11 +153,17 @@ pub mod __internal {
where F: FnOnce(&ParseSess) -> R
{
let p = CURRENT_SESS.with(|p| p.get());
assert!(!p.is_null());
assert!(!p.is_null(), "proc_macro::__internal::with_parse_sess() called \
before set_parse_sess()!");
f(unsafe { &*p })
}
}
fn parse_to_lex_err(mut err: DiagnosticBuilder) -> LexError {
err.cancel();
LexError { _inner: () }
}
#[stable(feature = "proc_macro_lib", since = "1.15.0")]
impl FromStr for TokenStream {
type Err = LexError;
@ -138,18 +172,10 @@ impl FromStr for TokenStream {
__internal::with_parse_sess(|sess| {
let src = src.to_string();
let name = "<proc-macro source code>".to_string();
let mut parser = parse::new_parser_from_source_str(sess, name, src);
let mut ret = TokenStream { inner: Vec::new() };
loop {
match parser.parse_item() {
Ok(Some(item)) => ret.inner.push(item),
Ok(None) => return Ok(ret),
Err(mut err) => {
err.cancel();
return Err(LexError { _inner: () })
}
}
}
let tts = try!(parse::parse_tts_from_source_str(name, src, sess)
.map_err(parse_to_lex_err));
Ok(__internal::token_stream_wrap(TokenStream_::from_tts(tts)))
})
}
}
@ -157,11 +183,6 @@ impl FromStr for TokenStream {
#[stable(feature = "proc_macro_lib", since = "1.15.0")]
impl fmt::Display for TokenStream {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
for item in self.inner.iter() {
let item = syntax::print::pprust::item_to_string(item);
try!(f.write_str(&item));
try!(f.write_str("\n"));
}
Ok(())
self.inner.fmt(f)
}
}

23
src/librustc_driver/driver.rs
View file

@ -681,6 +681,7 @@ pub fn phase_2_configure_and_expand<F>(sess: &Session,
should_test: sess.opts.test,
..syntax::ext::expand::ExpansionConfig::default(crate_name.to_string())
};
let mut ecx = ExtCtxt::new(&sess.parse_sess, cfg, &mut resolver);
let err_count = ecx.parse_sess.span_diagnostic.err_count();
@ -740,17 +741,6 @@ pub fn phase_2_configure_and_expand<F>(sess: &Session,
"checking for inline asm in case the target doesn't support it",
|| no_asm::check_crate(sess, &krate));
// Needs to go *after* expansion to be able to check the results of macro expansion.
time(time_passes, "complete gated feature checking", || {
sess.track_errors(|| {
syntax::feature_gate::check_crate(&krate,
&sess.parse_sess,
&sess.features.borrow(),
&attributes,
sess.opts.unstable_features);
})
})?;
time(sess.time_passes(),
"early lint checks",
|| lint::check_ast_crate(sess, &krate));
@ -768,6 +758,17 @@ pub fn phase_2_configure_and_expand<F>(sess: &Session,
Ok(())
})?;
// Needs to go *after* expansion to be able to check the results of macro expansion.
time(time_passes, "complete gated feature checking", || {
sess.track_errors(|| {
syntax::feature_gate::check_crate(&krate,
&sess.parse_sess,
&sess.features.borrow(),
&attributes,
sess.opts.unstable_features);
})
})?;
// Lower ast -> hir.
let hir_forest = time(sess.time_passes(), "lowering ast -> hir", || {
let hir_crate = lower_crate(sess, &krate, &mut resolver);

10
src/librustc_metadata/creader.rs
View file

@ -578,6 +578,7 @@ impl<'a> CrateLoader<'a> {
use proc_macro::__internal::Registry;
use rustc_back::dynamic_lib::DynamicLibrary;
use syntax_ext::deriving::custom::CustomDerive;
use syntax_ext::proc_macro_impl::AttrProcMacro;
let path = match dylib {
Some(dylib) => dylib,
@ -613,6 +614,15 @@ impl<'a> CrateLoader<'a> {
);
self.0.push((Symbol::intern(trait_name), Rc::new(derive)));
}
fn register_attr_proc_macro(&mut self,
name: &str,
expand: fn(TokenStream, TokenStream) -> TokenStream) {
let expand = SyntaxExtension::AttrProcMacro(
Box::new(AttrProcMacro { inner: expand })
);
self.0.push((Symbol::intern(name), Rc::new(expand)));
}
}
let mut my_registrar = MyRegistrar(Vec::new());

46
src/librustc_resolve/lib.rs
View file

@ -61,7 +61,7 @@ use syntax::ast::{FnDecl, ForeignItem, ForeignItemKind, Generics};
use syntax::ast::{Item, ItemKind, ImplItem, ImplItemKind};
use syntax::ast::{Local, Mutability, Pat, PatKind, Path};
use syntax::ast::{QSelf, TraitItemKind, TraitRef, Ty, TyKind};
use syntax::feature_gate::{emit_feature_err, GateIssue};
use syntax::feature_gate::{feature_err, emit_feature_err, GateIssue};
use syntax_pos::{Span, DUMMY_SP, MultiSpan};
use errors::DiagnosticBuilder;
@ -1123,6 +1123,12 @@ pub struct Resolver<'a> {
// Avoid duplicated errors for "name already defined".
name_already_seen: FxHashMap<Name, Span>,
// If `#![feature(proc_macro)]` is set
proc_macro_enabled: bool,
// A set of procedural macros imported by `#[macro_use]` that have already been warned about
warned_proc_macros: FxHashSet<Name>,
}
pub struct ResolverArenas<'a> {
@ -1227,6 +1233,8 @@ impl<'a> Resolver<'a> {
invocations.insert(Mark::root(),
arenas.alloc_invocation_data(InvocationData::root(graph_root)));
let features = session.features.borrow();
Resolver {
session: session,
@ -1284,7 +1292,9 @@ impl<'a> Resolver<'a> {
span: DUMMY_SP,
vis: ty::Visibility::Public,
}),
use_extern_macros: session.features.borrow().use_extern_macros,
// `#![feature(proc_macro)]` implies `#[feature(extern_macros)]`
use_extern_macros: features.use_extern_macros || features.proc_macro,
exported_macros: Vec::new(),
crate_loader: crate_loader,
@ -1296,6 +1306,8 @@ impl<'a> Resolver<'a> {
invocations: invocations,
name_already_seen: FxHashMap(),
whitelisted_legacy_custom_derives: Vec::new(),
proc_macro_enabled: features.proc_macro,
warned_proc_macros: FxHashSet(),
}
}
@ -1525,6 +1537,8 @@ impl<'a> Resolver<'a> {
debug!("(resolving item) resolving {}", name);
self.check_proc_macro_attrs(&item.attrs);
match item.node {
ItemKind::Enum(_, ref generics) |
ItemKind::Ty(_, ref generics) |
@ -1554,6 +1568,8 @@ impl<'a> Resolver<'a> {
walk_list!(this, visit_ty_param_bound, bounds);
for trait_item in trait_items {
this.check_proc_macro_attrs(&trait_item.attrs);
match trait_item.node {
TraitItemKind::Const(_, ref default) => {
// Only impose the restrictions of
@ -1738,6 +1754,7 @@ impl<'a> Resolver<'a> {
this.with_self_rib(Def::SelfTy(trait_id, Some(item_def_id)), |this| {
this.with_current_self_type(self_type, |this| {
for impl_item in impl_items {
this.check_proc_macro_attrs(&impl_item.attrs);
this.resolve_visibility(&impl_item.vis);
match impl_item.node {
ImplItemKind::Const(..) => {
@ -3184,6 +3201,31 @@ impl<'a> Resolver<'a> {
let msg = "`self` no longer imports values".to_string();
self.session.add_lint(lint::builtin::LEGACY_IMPORTS, id, span, msg);
}
fn check_proc_macro_attrs(&mut self, attrs: &[ast::Attribute]) {
if self.proc_macro_enabled { return; }
for attr in attrs {
let maybe_binding = self.builtin_macros.get(&attr.name()).cloned().or_else(|| {
let ident = Ident::with_empty_ctxt(attr.name());
self.resolve_lexical_macro_path_segment(ident, MacroNS, None).ok()
});
if let Some(binding) = maybe_binding {
if let SyntaxExtension::AttrProcMacro(..) = *binding.get_macro(self) {
attr::mark_known(attr);
let msg = "attribute procedural macros are experimental";
let feature = "proc_macro";
feature_err(&self.session.parse_sess, feature,
attr.span, GateIssue::Language, msg)
.span_note(binding.span, "procedural macro imported here")
.emit();
}
}
}
}
}
fn is_struct_like(def: Def) -> bool {

43
src/librustc_resolve/macros.rs
View file

@ -27,7 +27,7 @@ use syntax::ext::base::{NormalTT, Resolver as SyntaxResolver, SyntaxExtension};
use syntax::ext::expand::{Expansion, mark_tts};
use syntax::ext::hygiene::Mark;
use syntax::ext::tt::macro_rules;
use syntax::feature_gate::{emit_feature_err, GateIssue};
use syntax::feature_gate::{emit_feature_err, GateIssue, is_builtin_attr};
use syntax::fold::{self, Folder};
use syntax::ptr::P;
use syntax::symbol::keywords;
@ -183,6 +183,10 @@ impl<'a> base::Resolver for Resolver<'a> {
},
None => {}
}
if self.proc_macro_enabled && !is_builtin_attr(&attrs[i]) {
return Some(attrs.remove(i));
}
}
None
}
@ -373,6 +377,10 @@ impl<'a> Resolver<'a> {
let resolution = self.resolve_lexical_macro_path_segment(ident, MacroNS, Some(span));
let (legacy_resolution, resolution) = match (legacy_resolution, resolution) {
(Some(legacy_resolution), Ok(resolution)) => (legacy_resolution, resolution),
(Some(MacroBinding::Modern(binding)), Err(_)) => {
self.err_if_macro_use_proc_macro(ident.name, span, binding);
continue
},
_ => continue,
};
let (legacy_span, participle) = match legacy_resolution {
@ -469,4 +477,37 @@ impl<'a> Resolver<'a> {
self.exported_macros.push(def);
}
}
/// Error if `ext` is a Macros 1.1 procedural macro being imported by `#[macro_use]`
fn err_if_macro_use_proc_macro(&mut self, name: Name, use_span: Span,
binding: &NameBinding<'a>) {
use self::SyntaxExtension::*;
let krate = binding.def().def_id().krate;
// Plugin-based syntax extensions are exempt from this check
if krate == BUILTIN_MACROS_CRATE { return; }
let ext = binding.get_macro(self);
match *ext {
// If `ext` is a procedural macro, check if we've already warned about it
AttrProcMacro(_) | ProcMacro(_) => if !self.warned_proc_macros.insert(name) { return; },
_ => return,
}
let warn_msg = match *ext {
AttrProcMacro(_) => "attribute procedural macros cannot be \
imported with `#[macro_use]`",
ProcMacro(_) => "procedural macros cannot be imported with `#[macro_use]`",
_ => return,
};
let crate_name = self.session.cstore.crate_name(krate);
self.session.struct_span_err(use_span, warn_msg)
.help(&format!("instead, import the procedural macro like any other item: \
`use {}::{};`", crate_name, name))
.emit();
}
}

30
src/libsyntax/ext/expand.rs
View file

@ -364,7 +364,9 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
kind.expect_from_annotatables(items)
}
SyntaxExtension::AttrProcMacro(ref mac) => {
let attr_toks = TokenStream::from_tts(tts_for_attr(&attr, &self.cx.parse_sess));
let attr_toks = TokenStream::from_tts(tts_for_attr_args(&attr,
&self.cx.parse_sess));
let item_toks = TokenStream::from_tts(tts_for_item(&item, &self.cx.parse_sess));
let tok_result = mac.expand(self.cx, attr.span, attr_toks, item_toks);
@ -640,8 +642,30 @@ fn tts_for_item(item: &Annotatable, parse_sess: &ParseSess) -> Vec<TokenTree> {
string_to_tts(text, parse_sess)
}
fn tts_for_attr(attr: &ast::Attribute, parse_sess: &ParseSess) -> Vec<TokenTree> {
string_to_tts(pprust::attr_to_string(attr), parse_sess)
fn tts_for_attr_args(attr: &ast::Attribute, parse_sess: &ParseSess) -> Vec<TokenTree> {
use ast::MetaItemKind::*;
use print::pp::Breaks;
use print::pprust::PrintState;
let token_string = match attr.value.node {
// For `#[foo]`, an empty token
Word => return vec![],
// For `#[foo(bar, baz)]`, returns `(bar, baz)`
List(ref items) => pprust::to_string(|s| {
s.popen()?;
s.commasep(Breaks::Consistent,
&items[..],
|s, i| s.print_meta_list_item(&i))?;
s.pclose()
}),
// For `#[foo = "bar"]`, returns `= "bar"`
NameValue(ref lit) => pprust::to_string(|s| {
s.word_space("=")?;
s.print_literal(lit)
}),
};
string_to_tts(token_string, parse_sess)
}
fn string_to_tts(text: String, parse_sess: &ParseSess) -> Vec<TokenTree> {

67
src/libsyntax/feature_gate.rs
View file

@ -30,7 +30,7 @@ use ast::{self, NodeId, PatKind};
use attr;
use codemap::{CodeMap, Spanned};
use syntax_pos::Span;
use errors::{DiagnosticBuilder, Handler};
use errors::{DiagnosticBuilder, Handler, FatalError};
use visit::{self, FnKind, Visitor};
use parse::ParseSess;
use symbol::Symbol;
@ -319,6 +319,9 @@ declare_features! (
// The `unadjusted` ABI. Perma unstable.
(active, abi_unadjusted, "1.16.0", None),
// Macros 1.1
(active, proc_macro, "1.16.0", Some(35900)),
// Allows attributes on struct literal fields.
(active, struct_field_attributes, "1.16.0", Some(38814)),
@ -375,8 +378,6 @@ declare_features! (
// Allows `..` in tuple (struct) patterns
(accepted, dotdot_in_tuple_patterns, "1.14.0", Some(33627)),
(accepted, item_like_imports, "1.14.0", Some(35120)),
// Macros 1.1
(accepted, proc_macro, "1.15.0", Some(35900)),
);
// (changing above list without updating src/doc/reference.md makes @cmr sad)
@ -444,6 +445,10 @@ pub fn deprecated_attributes() -> Vec<&'static (&'static str, AttributeType, Att
BUILTIN_ATTRIBUTES.iter().filter(|a| a.2.is_deprecated()).collect()
}
pub fn is_builtin_attr(attr: &ast::Attribute) -> bool {
BUILTIN_ATTRIBUTES.iter().any(|&(builtin_name, _, _)| attr.check_name(builtin_name))
}
// Attributes that have a special meaning to rustc or rustdoc
pub const BUILTIN_ATTRIBUTES: &'static [(&'static str, AttributeType, AttributeGate)] = &[
// Normal attributes
@ -737,6 +742,16 @@ pub const BUILTIN_ATTRIBUTES: &'static [(&'static str, AttributeType, AttributeG
is currently unstable",
cfg_fn!(windows_subsystem))),
("proc_macro_attribute", Normal, Gated(Stability::Unstable,
"proc_macro",
"attribute proc macros are currently unstable",
cfg_fn!(proc_macro))),
("rustc_derive_registrar", Normal, Gated(Stability::Unstable,
"rustc_derive_registrar",
"used internally by rustc",
cfg_fn!(rustc_attrs))),
// Crate level attributes
("crate_name", CrateLevel, Ungated),
("crate_type", CrateLevel, Ungated),
@ -879,9 +894,10 @@ fn find_lang_feature_issue(feature: &str) -> Option<u32> {
issue
} else {
// search in Accepted or Removed features
ACCEPTED_FEATURES.iter().chain(REMOVED_FEATURES.iter())
.find(|t| t.0 == feature)
.unwrap().2
match ACCEPTED_FEATURES.iter().chain(REMOVED_FEATURES).find(|t| t.0 == feature) {
Some(&(_, _, issue)) => issue,
None => panic!("Feature `{}` is not declared anywhere", feature),
}
}
}
@ -1382,6 +1398,8 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
pub fn get_features(span_handler: &Handler, krate_attrs: &[ast::Attribute]) -> Features {
let mut features = Features::new();
let mut feature_checker = MutexFeatureChecker::default();
for attr in krate_attrs {
if !attr.check_name("feature") {
continue
@ -1405,6 +1423,7 @@ pub fn get_features(span_handler: &Handler, krate_attrs: &[ast::Attribute]) -> F
if let Some(&(_, _, _, setter)) = ACTIVE_FEATURES.iter()
.find(|& &(n, _, _, _)| name == n) {
*(setter(&mut features)) = true;
feature_checker.collect(&features, mi.span);
}
else if let Some(&(_, _, _)) = REMOVED_FEATURES.iter()
.find(|& &(n, _, _)| name == n) {
@ -1421,9 +1440,45 @@ pub fn get_features(span_handler: &Handler, krate_attrs: &[ast::Attribute]) -> F
}
}
feature_checker.check(span_handler);
features
}
// A collector for mutually-exclusive features and their flag spans
#[derive(Default)]
struct MutexFeatureChecker {
proc_macro: Option<Span>,
custom_attribute: Option<Span>,
}
impl MutexFeatureChecker {
// If this method turns out to be a hotspot due to branching,
// the branching can be eliminated by modifying `setter!()` to set these spans
// only for the features that need to be checked for mutual exclusion.
fn collect(&mut self, features: &Features, span: Span) {
if features.proc_macro {
// If self.proc_macro is None, set to Some(span)
self.proc_macro = self.proc_macro.or(Some(span));
}
if features.custom_attribute {
self.custom_attribute = self.custom_attribute.or(Some(span));
}
}
fn check(self, handler: &Handler) {
if let (Some(pm_span), Some(ca_span)) = (self.proc_macro, self.custom_attribute) {
handler.struct_span_err(pm_span, "Cannot use `#![feature(proc_macro)]` and \
`#![feature(custom_attribute)] at the same time")
.span_note(ca_span, "`#![feature(custom_attribute)]` declared here")
.emit();
panic!(FatalError);
}
}
}
pub fn check_crate(krate: &ast::Crate,
sess: &ParseSess,
features: &Features,

17
src/libsyntax_ext/deriving/custom.rs
View file

@ -77,8 +77,9 @@ impl MultiItemModifier for CustomDerive {
let inner = self.inner;
panic::catch_unwind(panic::AssertUnwindSafe(|| inner(input)))
});
let new_items = match res {
Ok(stream) => __internal::token_stream_items(stream),
let stream = match res {
Ok(stream) => stream,
Err(e) => {
let msg = "custom derive attribute panicked";
let mut err = ecx.struct_span_fatal(span, msg);
@ -94,6 +95,18 @@ impl MultiItemModifier for CustomDerive {
}
};
let new_items = __internal::set_parse_sess(&ecx.parse_sess, || {
match __internal::token_stream_parse_items(stream) {
Ok(new_items) => new_items,
Err(_) => {
// FIXME: handle this better
let msg = "custom derive produced unparseable tokens";
ecx.struct_span_fatal(span, msg).emit();
panic!(FatalError);
}
}
});
let mut res = vec![Annotatable::Item(item)];
// Reassign spans of all expanded items to the input `item`
// for better errors here.

2
src/libsyntax_ext/lib.rs
View file

@ -47,6 +47,8 @@ pub mod proc_macro_registrar;
// for custom_derive
pub mod deriving;
pub mod proc_macro_impl;
use std::rc::Rc;
use syntax::ast;
use syntax::ext::base::{MacroExpanderFn, NormalTT, MultiModifier, NamedSyntaxExtension};

58
src/libsyntax_ext/proc_macro_impl.rs Normal file
View file

@ -0,0 +1,58 @@
// Copyright 2016 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 std::panic;
use errors::FatalError;
use syntax::codemap::Span;
use syntax::ext::base::*;
use syntax::tokenstream::TokenStream;
use syntax::ext::base;
use proc_macro::TokenStream as TsShim;
use proc_macro::__internal;
pub struct AttrProcMacro {
pub inner: fn(TsShim, TsShim) -> TsShim,
}
impl base::AttrProcMacro for AttrProcMacro {
fn expand<'cx>(&self,
ecx: &'cx mut ExtCtxt,
span: Span,
annotation: TokenStream,
annotated: TokenStream)
-> TokenStream {
let annotation = __internal::token_stream_wrap(annotation);
let annotated = __internal::token_stream_wrap(annotated);
let res = __internal::set_parse_sess(&ecx.parse_sess, || {
panic::catch_unwind(panic::AssertUnwindSafe(|| (self.inner)(annotation, annotated)))
});
match res {
Ok(stream) => __internal::token_stream_inner(stream),
Err(e) => {
let msg = "custom attribute panicked";
let mut err = ecx.struct_span_fatal(span, msg);
if let Some(s) = e.downcast_ref::<String>() {
err.help(&format!("message: {}", s));
}
if let Some(s) = e.downcast_ref::<&'static str>() {
err.help(&format!("message: {}", s));
}
err.emit();
panic!(FatalError);
}
}
}
}

204
src/libsyntax_ext/proc_macro_registrar.rs
View file

@ -11,18 +11,20 @@
use std::mem;
use errors;
use syntax::ast::{self, Ident, NodeId};
use syntax::codemap::{ExpnInfo, NameAndSpan, MacroAttribute};
use syntax::ext::base::ExtCtxt;
use syntax::ext::build::AstBuilder;
use syntax::ext::expand::ExpansionConfig;
use syntax::parse::ParseSess;
use syntax::fold::Folder;
use syntax::parse::ParseSess;
use syntax::ptr::P;
use syntax::symbol::Symbol;
use syntax_pos::{Span, DUMMY_SP};
use syntax::visit::{self, Visitor};
use syntax_pos::{Span, DUMMY_SP};
use deriving;
struct CustomDerive {
@ -32,8 +34,14 @@ struct CustomDerive {
attrs: Vec<ast::Name>,
}
struct CollectCustomDerives<'a> {
struct AttrProcMacro {
function_name: Ident,
span: Span,
}
struct CollectProcMacros<'a> {
derives: Vec<CustomDerive>,
attr_macros: Vec<AttrProcMacro>,
in_root: bool,
handler: &'a errors::Handler,
is_proc_macro_crate: bool,
@ -50,16 +58,17 @@ pub fn modify(sess: &ParseSess,
let ecfg = ExpansionConfig::default("proc_macro".to_string());
let mut cx = ExtCtxt::new(sess, ecfg, resolver);
let derives = {
let mut collect = CollectCustomDerives {
let (derives, attr_macros) = {
let mut collect = CollectProcMacros {
derives: Vec::new(),
attr_macros: Vec::new(),
in_root: true,
handler: handler,
is_proc_macro_crate: is_proc_macro_crate,
is_test_crate: is_test_crate,
};
visit::walk_crate(&mut collect, &krate);
collect.derives
(collect.derives, collect.attr_macros)
};
if !is_proc_macro_crate {
@ -74,7 +83,7 @@ pub fn modify(sess: &ParseSess,
return krate;
}
krate.module.items.push(mk_registrar(&mut cx, &derives));
krate.module.items.push(mk_registrar(&mut cx, &derives, &attr_macros));
if krate.exported_macros.len() > 0 {
handler.err("cannot export macro_rules! macros from a `proc-macro` \
@ -84,7 +93,7 @@ pub fn modify(sess: &ParseSess,
return krate
}
impl<'a> CollectCustomDerives<'a> {
impl<'a> CollectProcMacros<'a> {
fn check_not_pub_in_root(&self, vis: &ast::Visibility, sp: Span) {
if self.is_proc_macro_crate &&
self.in_root &&
@ -92,61 +101,11 @@ impl<'a> CollectCustomDerives<'a> {
self.handler.span_err(sp,
"`proc-macro` crate types cannot \
export any items other than functions \
tagged with `#[proc_macro_derive]` \
currently");
}
}
}
impl<'a> Visitor<'a> for CollectCustomDerives<'a> {
fn visit_item(&mut self, item: &'a ast::Item) {
let mut attrs = item.attrs.iter().filter(|a| a.check_name("proc_macro_derive"));
// First up, make sure we're checking a bare function. If we're not then
// we're just not interested in this item.
//
// If we find one, try to locate a `#[proc_macro_derive]` attribute on
// it.
match item.node {
ast::ItemKind::Fn(..) => {}
_ => {
// Check for invalid use of proc_macro_derive
if let Some(attr) = attrs.next() {
self.handler.span_err(attr.span(),
"the `#[proc_macro_derive]` \
attribute may only be used \
on bare functions");
return;
}
self.check_not_pub_in_root(&item.vis, item.span);
return visit::walk_item(self, item)
tagged with `#[proc_macro_derive]` currently");
}
}
let attr = match attrs.next() {
Some(attr) => attr,
None => {
self.check_not_pub_in_root(&item.vis, item.span);
return visit::walk_item(self, item)
}
};
if let Some(a) = attrs.next() {
self.handler.span_err(a.span(), "multiple `#[proc_macro_derive]` \
attributes found");
}
if self.is_test_crate {
return;
}
if !self.is_proc_macro_crate {
self.handler.span_err(attr.span(),
"the `#[proc_macro_derive]` attribute is \
only usable with crates of the `proc-macro` \
crate type");
}
fn collect_custom_derive(&mut self, item: &'a ast::Item, attr: &'a ast::Attribute) {
// Once we've located the `#[proc_macro_derive]` attribute, verify
// that it's of the form `#[proc_macro_derive(Foo)]` or
// `#[proc_macro_derive(Foo, attributes(A, ..))]`
@ -232,6 +191,101 @@ impl<'a> Visitor<'a> for CollectCustomDerives<'a> {
};
self.handler.span_err(item.span, msg);
}
}
fn collect_attr_proc_macro(&mut self, item: &'a ast::Item, attr: &'a ast::Attribute) {
if let Some(_) = attr.meta_item_list() {
self.handler.span_err(attr.span, "`#[proc_macro_attribute]` attribute
cannot contain any meta items");
return;
}
if self.in_root && item.vis == ast::Visibility::Public {
self.attr_macros.push(AttrProcMacro {
span: item.span,
function_name: item.ident,
});
} else {
let msg = if !self.in_root {
"functions tagged with `#[proc_macro_attribute]` must \
currently reside in the root of the crate"
} else {
"functions tagged with `#[proc_macro_attribute]` must be `pub`"
};
self.handler.span_err(item.span, msg);
}
}
}
impl<'a> Visitor<'a> for CollectProcMacros<'a> {
fn visit_item(&mut self, item: &'a ast::Item) {
// First up, make sure we're checking a bare function. If we're not then
// we're just not interested in this item.
//
// If we find one, try to locate a `#[proc_macro_derive]` attribute on
// it.
let is_fn = match item.node {
ast::ItemKind::Fn(..) => true,
_ => false,
};
let mut found_attr: Option<&'a ast::Attribute> = None;
for attr in &item.attrs {
if attr.check_name("proc_macro_derive") || attr.check_name("proc_macro_attribute") {
if let Some(prev_attr) = found_attr {
let msg = if attr.name() == prev_attr.name() {
format!("Only one `#[{}]` attribute is allowed on any given function",
attr.name())
} else {
format!("`#[{}]` and `#[{}]` attributes cannot both be applied \
to the same function", attr.name(), prev_attr.name())
};
self.handler.struct_span_err(attr.span(), &msg)
.span_note(prev_attr.span(), "Previous attribute here")
.emit();
return;
}
found_attr = Some(attr);
}
}
let attr = match found_attr {
None => {
self.check_not_pub_in_root(&item.vis, item.span);
return visit::walk_item(self, item);
},
Some(attr) => attr,
};
if !is_fn {
let msg = format!("the `#[{}]` attribute may only be used on bare functions",
attr.name());
self.handler.span_err(attr.span(), &msg);
return;
}
if self.is_test_crate {
return;
}
if !self.is_proc_macro_crate {
let msg = format!("the `#[{}]` attribute is only usable with crates of the \
`proc-macro` crate type", attr.name());
self.handler.span_err(attr.span(), &msg);
return;
}
if attr.check_name("proc_macro_derive") {
self.collect_custom_derive(item, attr);
} else if attr.check_name("proc_macro_attribute") {
self.collect_attr_proc_macro(item, attr);
};
visit::walk_item(self, item);
}
@ -265,7 +319,8 @@ impl<'a> Visitor<'a> for CollectCustomDerives<'a> {
// }
// }
fn mk_registrar(cx: &mut ExtCtxt,
custom_derives: &[CustomDerive]) -> P<ast::Item> {
custom_derives: &[CustomDerive],
custom_attrs: &[AttrProcMacro]) -> P<ast::Item> {
let eid = cx.codemap().record_expansion(ExpnInfo {
call_site: DUMMY_SP,
callee: NameAndSpan {
@ -286,25 +341,36 @@ fn mk_registrar(cx: &mut ExtCtxt,
let registry = Ident::from_str("Registry");
let registrar = Ident::from_str("registrar");
let register_custom_derive = Ident::from_str("register_custom_derive");
let stmts = custom_derives.iter().map(|cd| {
let register_attr_proc_macro = Ident::from_str("register_attr_proc_macro");
let mut stmts = custom_derives.iter().map(|cd| {
let path = cx.path_global(cd.span, vec![cd.function_name]);
let trait_name = cx.expr_str(cd.span, cd.trait_name);
let attrs = cx.expr_vec_slice(
span,
cd.attrs.iter().map(|&s| cx.expr_str(cd.span, s)).collect::<Vec<_>>()
);
(path, trait_name, attrs)
}).map(|(path, trait_name, attrs)| {
let registrar = cx.expr_ident(span, registrar);
let ufcs_path = cx.path(span, vec![proc_macro, __internal, registry,
register_custom_derive]);
cx.expr_call(span,
cx.expr_path(ufcs_path),
vec![registrar, trait_name, cx.expr_path(path), attrs])
}).map(|expr| {
cx.stmt_expr(expr)
cx.stmt_expr(cx.expr_call(span, cx.expr_path(ufcs_path),
vec![registrar, trait_name, cx.expr_path(path), attrs]))
}).collect::<Vec<_>>();
stmts.extend(custom_attrs.iter().map(|ca| {
let name = cx.expr_str(ca.span, ca.function_name.name);
let path = cx.path_global(ca.span, vec![ca.function_name]);
let registrar = cx.expr_ident(ca.span, registrar);
let ufcs_path = cx.path(span,
vec![proc_macro, __internal, registry, register_attr_proc_macro]);
cx.stmt_expr(cx.expr_call(span, cx.expr_path(ufcs_path),
vec![registrar, name, cx.expr_path(path)]))
}));
let path = cx.path(span, vec![proc_macro, __internal, registry]);
let registrar_path = cx.ty_path(path);
let arg_ty = cx.ty_rptr(span, registrar_path, None, ast::Mutability::Mutable);

23
src/test/compile-fail-fulldeps/proc-macro/auxiliary/attr_proc_macro.rs Normal file
View file

@ -0,0 +1,23 @@
// Copyright 2016 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.
// force-host
// no-prefer-dynamic
#![feature(proc_macro)]
#![crate_type = "proc-macro"]
extern crate proc_macro;
use proc_macro::TokenStream;
#[proc_macro_attribute]
pub fn attr_proc_macro(_: TokenStream, input: TokenStream) -> TokenStream {
input
}

3
src/test/compile-fail-fulldeps/proc-macro/derive-bad.rs
View file

@ -16,8 +16,7 @@ extern crate derive_bad;
#[derive(
A
)]
//~^^ ERROR: custom derive attribute panicked
//~| HELP: called `Result::unwrap()` on an `Err` value: LexError
//~^^ ERROR: custom derive produced unparseable tokens
struct A;
fn main() {}

24
src/test/compile-fail-fulldeps/proc-macro/feature-gate-proc_macro.rs Normal file
View file

@ -0,0 +1,24 @@
// Copyright 2016 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.
// aux-build:attr_proc_macro.rs
// gate-test-proc_macro
#![feature(use_extern_macros)]
extern crate attr_proc_macro;
use attr_proc_macro::attr_proc_macro;
#[attr_proc_macro]
//~^ ERROR: attribute procedural macros are experimental
struct Foo;
fn main() {
let _ = Foo;
}

22
src/test/compile-fail-fulldeps/proc-macro/macro-use-attr.rs Normal file
View file

@ -0,0 +1,22 @@
// Copyright 2016 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.
// aux-build:attr_proc_macro.rs
#![feature(proc_macro)]
#[macro_use] extern crate attr_proc_macro;
#[attr_proc_macro]
//~^ ERROR: attribute procedural macros cannot be imported with `#[macro_use]`
struct Foo;
fn main() {
let _ = Foo;
}

24
src/test/compile-fail-fulldeps/proc-macro/proc-macro-custom-attr-mutex.rs Normal file
View file

@ -0,0 +1,24 @@
// Copyright 2016 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.
// aux-build:attr_proc_macro.rs
#![feature(proc_macro, custom_attribute)]
//~^ ERROR Cannot use `#![feature(proc_macro)]` and `#![feature(custom_attribute)] at the same time
extern crate attr_proc_macro;
use attr_proc_macro::attr_proc_macro;
#[attr_proc_macro]
fn foo() {}
fn main() {
foo();
}

3
src/test/compile-fail/const-fn-stability.rs
View file

@ -16,7 +16,9 @@ const fn foo() -> usize { 0 } //~ ERROR const fn is unstable
trait Foo {
const fn foo() -> u32; //~ ERROR const fn is unstable
//~| ERROR trait fns cannot be declared const
const fn bar() -> u32 { 0 } //~ ERROR const fn is unstable
//~| ERROR trait fns cannot be declared const
}
impl Foo {
@ -25,6 +27,7 @@ impl Foo {
impl Foo for u32 {
const fn foo() -> u32 { 0 } //~ ERROR const fn is unstable
//~| ERROR trait fns cannot be declared const
}
static FOO: usize = foo();

2
src/test/compile-fail/feature-gate-no-debug.rs
View file

@ -8,5 +8,7 @@
// option. This file may not be copied, modified, or distributed
// except according to those terms.
#![allow(deprecated)]
#[no_debug] //~ ERROR the `#[no_debug]` attribute is
fn main() {}

24
src/test/run-pass-fulldeps/proc-macro/attr-args.rs Normal file
View file

@ -0,0 +1,24 @@
// Copyright 2016 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.
// aux-build:attr-args.rs
#![allow(warnings)]
#![feature(proc_macro)]
extern crate attr_args;
use attr_args::attr_with_args;
#[attr_with_args(text = "Hello, world!")]
fn foo() {}
fn main() {
assert_eq!(foo(), "Hello, world!");
}

32
src/test/run-pass-fulldeps/proc-macro/auxiliary/attr-args.rs Normal file
View file

@ -0,0 +1,32 @@
// Copyright 2016 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.
// no-prefer-dynamic
#![feature(proc_macro)]
#![crate_type = "proc-macro"]
extern crate proc_macro;
use proc_macro::TokenStream;
#[proc_macro_attribute]
pub fn attr_with_args(args: TokenStream, input: TokenStream) -> TokenStream {
let args = args.to_string();
assert_eq!(args, r#"( text = "Hello, world!" )"#);
let input = input.to_string();
assert_eq!(input, "fn foo ( ) { }");
r#"
fn foo() -> &'static str { "Hello, world!" }
"#.parse().unwrap()
}

2
src/test/run-pass-fulldeps/proc-macro/auxiliary/derive-atob.rs
View file

@ -19,6 +19,6 @@ use proc_macro::TokenStream;
#[proc_macro_derive(AToB)]
pub fn derive(input: TokenStream) -> TokenStream {
let input = input.to_string();
assert_eq!(input, "#[derive(Copy, Clone)]\nstruct A;\n");
assert_eq!(input, "#[derive(Copy, Clone)]\nstruct A;");
"struct B;".parse().unwrap()
}

2
src/test/run-pass-fulldeps/proc-macro/auxiliary/derive-ctod.rs
View file

@ -19,6 +19,6 @@ use proc_macro::TokenStream;
#[proc_macro_derive(CToD)]
pub fn derive(input: TokenStream) -> TokenStream {
let input = input.to_string();
assert_eq!(input, "struct C;\n");
assert_eq!(input, "struct C;");
"struct D;".parse().unwrap()
}

4
src/test/run-pass-fulldeps/proc-macro/auxiliary/derive-same-struct.rs
View file

@ -18,12 +18,12 @@ use proc_macro::TokenStream;
#[proc_macro_derive(AToB)]
pub fn derive1(input: TokenStream) -> TokenStream {
println!("input1: {:?}", input.to_string());
assert_eq!(input.to_string(), "struct A;\n");
assert_eq!(input.to_string(), "struct A;");
"#[derive(BToC)] struct B;".parse().unwrap()
}
#[proc_macro_derive(BToC)]
pub fn derive2(input: TokenStream) -> TokenStream {
assert_eq!(input.to_string(), "struct B;\n");
assert_eq!(input.to_string(), "struct B;");
"struct C;".parse().unwrap()
}

2
src/tools/tidy/src/features.rs
View file

@ -172,7 +172,7 @@ pub fn check(path: &Path, bad: &mut bool) {
"use_extern_macros", "staged_api", "const_indexing",
"unboxed_closures", "stmt_expr_attributes",
"cfg_target_thread_local", "unwind_attributes",
"inclusive_range_syntax"
"inclusive_range_syntax", "proc_macro"
];
// Only check the number of lang features.