rust/src/librustc/metadata/creader.rs
Keegan McAllister 6d15c6749c Implement #[plugin_registrar]
See RFC 22.

[breaking-change]
2014-06-09 14:29:29 -07:00

458 lines
17 KiB
Rust

// 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.
#![allow(non_camel_case_types)]
//! Validates all used crates and extern libraries and loads their metadata
use back::link;
use back::svh::Svh;
use driver::session::Session;
use driver::{driver, config};
use metadata::cstore;
use metadata::cstore::{CStore, CrateSource};
use metadata::decoder;
use metadata::loader;
use metadata::loader::CratePaths;
use plugin::load::PluginMetadata;
use std::rc::Rc;
use std::collections::HashMap;
use syntax::ast;
use syntax::abi;
use syntax::attr;
use syntax::attr::AttrMetaMethods;
use syntax::codemap::{Span};
use syntax::diagnostic::SpanHandler;
use syntax::parse::token::InternedString;
use syntax::parse::token;
use syntax::crateid::CrateId;
use syntax::visit;
struct Env<'a> {
sess: &'a Session,
next_crate_num: ast::CrateNum,
}
// Traverses an AST, reading all the information about use'd crates and extern
// libraries necessary for later resolving, typechecking, linking, etc.
pub fn read_crates(sess: &Session,
krate: &ast::Crate) {
let mut e = Env {
sess: sess,
next_crate_num: sess.cstore.next_crate_num(),
};
visit_crate(&e, krate);
visit::walk_crate(&mut e, krate, ());
dump_crates(&sess.cstore);
warn_if_multiple_versions(sess.diagnostic(), &sess.cstore)
}
impl<'a> visit::Visitor<()> for Env<'a> {
fn visit_view_item(&mut self, a: &ast::ViewItem, _: ()) {
visit_view_item(self, a);
visit::walk_view_item(self, a, ());
}
fn visit_item(&mut self, a: &ast::Item, _: ()) {
visit_item(self, a);
visit::walk_item(self, a, ());
}
}
fn dump_crates(cstore: &CStore) {
debug!("resolved crates:");
cstore.iter_crate_data_origins(|_, data, opt_source| {
debug!("crate_id: {}", data.crate_id());
debug!(" cnum: {}", data.cnum);
debug!(" hash: {}", data.hash());
opt_source.map(|cs| {
let CrateSource { dylib, rlib, cnum: _ } = cs;
dylib.map(|dl| debug!(" dylib: {}", dl.display()));
rlib.map(|rl| debug!(" rlib: {}", rl.display()));
});
})
}
fn warn_if_multiple_versions(diag: &SpanHandler, cstore: &CStore) {
let mut map = HashMap::new();
cstore.iter_crate_data(|cnum, data| {
let crateid = data.crate_id();
let key = (crateid.name.clone(), crateid.path.clone());
map.find_or_insert_with(key, |_| Vec::new()).push(cnum);
});
for ((name, _), dupes) in map.move_iter() {
if dupes.len() == 1 { continue }
diag.handler().warn(
format!("using multiple versions of crate `{}`",
name).as_slice());
for dupe in dupes.move_iter() {
let data = cstore.get_crate_data(dupe);
diag.span_note(data.span, "used here");
loader::note_crateid_attr(diag, &data.crate_id());
}
}
}
fn visit_crate(e: &Env, c: &ast::Crate) {
for a in c.attrs.iter().filter(|m| m.name().equiv(&("link_args"))) {
match a.value_str() {
Some(ref linkarg) => e.sess.cstore.add_used_link_args(linkarg.get()),
None => { /* fallthrough */ }
}
}
}
fn should_link(i: &ast::ViewItem) -> bool {
i.attrs.iter().all(|attr| {
attr.name().get() != "phase" ||
attr.meta_item_list().map_or(false, |phases| {
attr::contains_name(phases.as_slice(), "link")
})
})
}
fn visit_view_item(e: &mut Env, i: &ast::ViewItem) {
if !should_link(i) {
return;
}
match extract_crate_info(e, i) {
Some(info) => {
let (cnum, _, _) = resolve_crate(e,
&None,
info.ident.as_slice(),
&info.crate_id,
None,
i.span);
e.sess.cstore.add_extern_mod_stmt_cnum(info.id, cnum);
}
None => ()
}
}
struct CrateInfo {
ident: String,
crate_id: CrateId,
id: ast::NodeId,
should_link: bool,
}
fn extract_crate_info(e: &Env, i: &ast::ViewItem) -> Option<CrateInfo> {
match i.node {
ast::ViewItemExternCrate(ident, ref path_opt, id) => {
let ident = token::get_ident(ident);
debug!("resolving extern crate stmt. ident: {:?} path_opt: {:?}",
ident, path_opt);
let crate_id = match *path_opt {
Some((ref path_str, _)) => {
let crateid: Option<CrateId> = from_str(path_str.get());
match crateid {
None => {
e.sess.span_err(i.span, "malformed crate id");
return None
}
Some(id) => id
}
}
None => from_str(ident.get().to_str().as_slice()).unwrap()
};
Some(CrateInfo {
ident: ident.get().to_string(),
crate_id: crate_id,
id: id,
should_link: should_link(i),
})
}
_ => None
}
}
fn visit_item(e: &Env, i: &ast::Item) {
match i.node {
ast::ItemForeignMod(ref fm) => {
if fm.abi == abi::Rust || fm.abi == abi::RustIntrinsic {
return;
}
// First, add all of the custom link_args attributes
let link_args = i.attrs.iter()
.filter_map(|at| if at.name().equiv(&("link_args")) {
Some(at)
} else {
None
})
.collect::<Vec<&ast::Attribute>>();
for m in link_args.iter() {
match m.value_str() {
Some(linkarg) => e.sess.cstore.add_used_link_args(linkarg.get()),
None => { /* fallthrough */ }
}
}
// Next, process all of the #[link(..)]-style arguments
let link_args = i.attrs.iter()
.filter_map(|at| if at.name().equiv(&("link")) {
Some(at)
} else {
None
})
.collect::<Vec<&ast::Attribute>>();
for m in link_args.iter() {
match m.meta_item_list() {
Some(items) => {
let kind = items.iter().find(|k| {
k.name().equiv(&("kind"))
}).and_then(|a| a.value_str());
let kind = match kind {
Some(k) => {
if k.equiv(&("static")) {
cstore::NativeStatic
} else if e.sess.targ_cfg.os == abi::OsMacos &&
k.equiv(&("framework")) {
cstore::NativeFramework
} else if k.equiv(&("framework")) {
e.sess.span_err(m.span,
"native frameworks are only available \
on OSX targets");
cstore::NativeUnknown
} else {
e.sess.span_err(m.span,
format!("unknown kind: `{}`",
k).as_slice());
cstore::NativeUnknown
}
}
None => cstore::NativeUnknown
};
let n = items.iter().find(|n| {
n.name().equiv(&("name"))
}).and_then(|a| a.value_str());
let n = match n {
Some(n) => n,
None => {
e.sess.span_err(m.span,
"#[link(...)] specified without \
`name = \"foo\"`");
InternedString::new("foo")
}
};
if n.get().is_empty() {
e.sess.span_err(m.span,
"#[link(name = \"\")] given with \
empty name");
} else {
e.sess
.cstore
.add_used_library(n.get().to_string(), kind);
}
}
None => {}
}
}
}
_ => { }
}
}
fn existing_match(e: &Env, crate_id: &CrateId,
hash: Option<&Svh>) -> Option<ast::CrateNum> {
let mut ret = None;
e.sess.cstore.iter_crate_data(|cnum, data| {
let other_id = data.crate_id();
if crate_id.matches(&other_id) {
let other_hash = data.hash();
match hash {
Some(hash) if *hash != other_hash => {}
Some(..) | None => { ret = Some(cnum); }
}
}
});
return ret;
}
fn register_crate<'a>(e: &mut Env,
root: &Option<CratePaths>,
ident: &str,
crate_id: &CrateId,
span: Span,
lib: loader::Library)
-> (ast::CrateNum, Rc<cstore::crate_metadata>,
cstore::CrateSource) {
// Claim this crate number and cache it
let cnum = e.next_crate_num;
e.next_crate_num += 1;
// Stash paths for top-most crate locally if necessary.
let crate_paths = if root.is_none() {
Some(CratePaths {
ident: ident.to_string(),
dylib: lib.dylib.clone(),
rlib: lib.rlib.clone(),
})
} else {
None
};
// Maintain a reference to the top most crate.
let root = if root.is_some() { root } else { &crate_paths };
let cnum_map = resolve_crate_deps(e, root, lib.metadata.as_slice(), span);
let loader::Library{ dylib, rlib, metadata } = lib;
let cmeta = Rc::new( cstore::crate_metadata {
name: crate_id.name.to_string(),
data: metadata,
cnum_map: cnum_map,
cnum: cnum,
span: span,
});
let source = cstore::CrateSource {
dylib: dylib,
rlib: rlib,
cnum: cnum,
};
e.sess.cstore.set_crate_data(cnum, cmeta.clone());
e.sess.cstore.add_used_crate_source(source.clone());
(cnum, cmeta, source)
}
fn resolve_crate<'a>(e: &mut Env,
root: &Option<CratePaths>,
ident: &str,
crate_id: &CrateId,
hash: Option<&Svh>,
span: Span)
-> (ast::CrateNum, Rc<cstore::crate_metadata>,
cstore::CrateSource) {
match existing_match(e, crate_id, hash) {
None => {
let id_hash = link::crate_id_hash(crate_id);
let mut load_ctxt = loader::Context {
sess: e.sess,
span: span,
ident: ident,
crate_id: crate_id,
id_hash: id_hash.as_slice(),
hash: hash.map(|a| &*a),
filesearch: e.sess.target_filesearch(),
os: config::cfg_os_to_meta_os(e.sess.targ_cfg.os),
triple: e.sess.targ_cfg.target_strs.target_triple.as_slice(),
root: root,
rejected_via_hash: vec!(),
rejected_via_triple: vec!(),
};
let library = load_ctxt.load_library_crate();
register_crate(e, root, ident, crate_id, span, library)
}
Some(cnum) => (cnum,
e.sess.cstore.get_crate_data(cnum),
e.sess.cstore.get_used_crate_source(cnum).unwrap())
}
}
// Go through the crate metadata and load any crates that it references
fn resolve_crate_deps(e: &mut Env,
root: &Option<CratePaths>,
cdata: &[u8], span : Span)
-> cstore::cnum_map {
debug!("resolving deps of external crate");
// The map from crate numbers in the crate we're resolving to local crate
// numbers
decoder::get_crate_deps(cdata).iter().map(|dep| {
debug!("resolving dep crate {} hash: `{}`", dep.crate_id, dep.hash);
let (local_cnum, _, _) = resolve_crate(e, root,
dep.crate_id.name.as_slice(),
&dep.crate_id,
Some(&dep.hash),
span);
(dep.cnum, local_cnum)
}).collect()
}
pub struct PluginMetadataReader<'a> {
env: Env<'a>,
}
impl<'a> PluginMetadataReader<'a> {
pub fn new(sess: &'a Session) -> PluginMetadataReader<'a> {
PluginMetadataReader {
env: Env {
sess: sess,
next_crate_num: sess.cstore.next_crate_num(),
}
}
}
pub fn read_plugin_metadata(&mut self, krate: &ast::ViewItem) -> PluginMetadata {
let info = extract_crate_info(&self.env, krate).unwrap();
let target_triple = self.env.sess.targ_cfg.target_strs.target_triple.as_slice();
let is_cross = target_triple != driver::host_triple();
let mut should_link = info.should_link && !is_cross;
let id_hash = link::crate_id_hash(&info.crate_id);
let os = config::get_os(driver::host_triple()).unwrap();
let mut load_ctxt = loader::Context {
sess: self.env.sess,
span: krate.span,
ident: info.ident.as_slice(),
crate_id: &info.crate_id,
id_hash: id_hash.as_slice(),
hash: None,
filesearch: self.env.sess.host_filesearch(),
triple: driver::host_triple(),
os: config::cfg_os_to_meta_os(os),
root: &None,
rejected_via_hash: vec!(),
rejected_via_triple: vec!(),
};
let library = match load_ctxt.maybe_load_library_crate() {
Some (l) => l,
None if is_cross => {
// try loading from target crates (only valid if there are
// no syntax extensions)
load_ctxt.triple = target_triple;
load_ctxt.os = config::cfg_os_to_meta_os(self.env.sess.targ_cfg.os);
load_ctxt.filesearch = self.env.sess.target_filesearch();
let lib = load_ctxt.load_library_crate();
if decoder::get_plugin_registrar_fn(lib.metadata.as_slice()).is_some() {
let message = format!("crate `{}` contains a plugin_registrar fn but \
only a version for triple `{}` could be found (need {})",
info.ident, target_triple, driver::host_triple());
self.env.sess.span_err(krate.span, message.as_slice());
// need to abort now because the syntax expansion
// code will shortly attempt to load and execute
// code from the found library.
self.env.sess.abort_if_errors();
}
should_link = info.should_link;
lib
}
None => { load_ctxt.report_load_errs(); unreachable!() },
};
let macros = decoder::get_exported_macros(library.metadata.as_slice());
let registrar = decoder::get_plugin_registrar_fn(library.metadata.as_slice()).map(|id| {
decoder::get_symbol(library.metadata.as_slice(), id).to_string()
});
let pc = PluginMetadata {
lib: library.dylib.clone(),
macros: macros.move_iter().map(|x| x.to_string()).collect(),
registrar_symbol: registrar,
};
if should_link {
// register crate now to avoid double-reading metadata
register_crate(&mut self.env, &None, info.ident.as_slice(),
&info.crate_id, krate.span, library);
}
pc
}
}