rust/src/librustc_metadata/creader.rs
bors 91f057de35 Auto merge of #36203 - petrochenkov:uvsdot, r=nrc
Replace `_, _` with `..` in patterns

This is how https://github.com/rust-lang/rust/issues/33627 looks in action.

Looks especially nice in leftmost/rightmost positions `(first, ..)`/`(.., last)`.
I haven't touched libsyntax intentionally because the feature is still unstable.
2016-09-04 14:03:01 -07:00

1234 lines
49 KiB
Rust

// Copyright 2012-2015 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 cstore::{self, CStore, CrateSource, MetadataBlob};
use decoder;
use loader::{self, CratePaths};
use rustc::hir::def_id::DefIndex;
use rustc::hir::svh::Svh;
use rustc::dep_graph::{DepGraph, DepNode};
use rustc::session::{config, Session};
use rustc::session::config::PanicStrategy;
use rustc::session::search_paths::PathKind;
use rustc::middle::cstore::{CrateStore, validate_crate_name, ExternCrate};
use rustc::util::nodemap::{FnvHashMap, FnvHashSet};
use rustc::hir::map as hir_map;
use std::cell::{RefCell, Cell};
use std::path::PathBuf;
use std::rc::Rc;
use std::fs;
use syntax::ast;
use syntax::abi::Abi;
use syntax::codemap;
use syntax::parse;
use syntax::attr;
use syntax::parse::token::InternedString;
use syntax::visit;
use syntax_pos::{self, Span, mk_sp, Pos};
use log;
struct LocalCrateReader<'a> {
sess: &'a Session,
cstore: &'a CStore,
creader: CrateReader<'a>,
krate: &'a ast::Crate,
definitions: &'a hir_map::Definitions,
}
pub struct CrateReader<'a> {
sess: &'a Session,
cstore: &'a CStore,
next_crate_num: ast::CrateNum,
foreign_item_map: FnvHashMap<String, Vec<ast::NodeId>>,
local_crate_name: String,
local_crate_config: ast::CrateConfig,
}
impl<'a> visit::Visitor for LocalCrateReader<'a> {
fn visit_item(&mut self, a: &ast::Item) {
self.process_item(a);
visit::walk_item(self, a);
}
}
fn dump_crates(cstore: &CStore) {
info!("resolved crates:");
cstore.iter_crate_data_origins(|_, data, opt_source| {
info!(" name: {}", data.name());
info!(" cnum: {}", data.cnum);
info!(" hash: {}", data.hash());
info!(" reqd: {}", data.explicitly_linked.get());
opt_source.map(|cs| {
let CrateSource { dylib, rlib, cnum: _ } = cs;
dylib.map(|dl| info!(" dylib: {}", dl.0.display()));
rlib.map(|rl| info!(" rlib: {}", rl.0.display()));
});
})
}
fn should_link(i: &ast::Item) -> bool {
!attr::contains_name(&i.attrs, "no_link")
}
#[derive(Debug)]
struct CrateInfo {
ident: String,
name: String,
id: ast::NodeId,
should_link: bool,
}
fn register_native_lib(sess: &Session,
cstore: &CStore,
span: Option<Span>,
name: String,
kind: cstore::NativeLibraryKind) {
if name.is_empty() {
match span {
Some(span) => {
struct_span_err!(sess, span, E0454,
"#[link(name = \"\")] given with empty name")
.span_label(span, &format!("empty name given"))
.emit();
}
None => {
sess.err("empty library name given via `-l`");
}
}
return
}
let is_osx = sess.target.target.options.is_like_osx;
if kind == cstore::NativeFramework && !is_osx {
let msg = "native frameworks are only available on OSX targets";
match span {
Some(span) => {
span_err!(sess, span, E0455,
"{}", msg)
}
None => sess.err(msg),
}
}
cstore.add_used_library(name, kind);
}
// Extra info about a crate loaded for plugins or exported macros.
struct ExtensionCrate {
metadata: PMDSource,
dylib: Option<PathBuf>,
target_only: bool,
ident: String,
name: String,
span: Span,
should_link: bool,
}
enum PMDSource {
Registered(Rc<cstore::CrateMetadata>),
Owned(loader::Library),
}
impl PMDSource {
pub fn as_slice<'a>(&'a self) -> &'a [u8] {
match *self {
PMDSource::Registered(ref cmd) => cmd.data(),
PMDSource::Owned(ref lib) => lib.metadata.as_slice(),
}
}
}
enum LoadResult {
Previous(ast::CrateNum),
Loaded(loader::Library),
}
pub struct Macros {
pub macro_rules: Vec<ast::MacroDef>,
/// An array of pairs where the first element is the name of the custom
/// derive (e.g. the trait being derived) and the second element is the
/// index of the definition.
pub custom_derive_registrar: Option<DefIndex>,
pub svh: Svh,
pub dylib: Option<PathBuf>,
}
impl<'a> CrateReader<'a> {
pub fn new(sess: &'a Session,
cstore: &'a CStore,
local_crate_name: &str,
local_crate_config: ast::CrateConfig)
-> CrateReader<'a> {
CrateReader {
sess: sess,
cstore: cstore,
next_crate_num: cstore.next_crate_num(),
foreign_item_map: FnvHashMap(),
local_crate_name: local_crate_name.to_owned(),
local_crate_config: local_crate_config,
}
}
fn extract_crate_info(&self, i: &ast::Item) -> Option<CrateInfo> {
match i.node {
ast::ItemKind::ExternCrate(ref path_opt) => {
debug!("resolving extern crate stmt. ident: {} path_opt: {:?}",
i.ident, path_opt);
let name = match *path_opt {
Some(name) => {
validate_crate_name(Some(self.sess), &name.as_str(),
Some(i.span));
name.to_string()
}
None => i.ident.to_string(),
};
Some(CrateInfo {
ident: i.ident.to_string(),
name: name,
id: i.id,
should_link: should_link(i),
})
}
_ => None
}
}
fn existing_match(&self, name: &str, hash: Option<&Svh>, kind: PathKind)
-> Option<ast::CrateNum> {
let mut ret = None;
self.cstore.iter_crate_data(|cnum, data| {
if data.name != name { return }
match hash {
Some(hash) if *hash == data.hash() => { ret = Some(cnum); return }
Some(..) => return,
None => {}
}
// When the hash is None we're dealing with a top-level dependency
// in which case we may have a specification on the command line for
// this library. Even though an upstream library may have loaded
// something of the same name, we have to make sure it was loaded
// from the exact same location as well.
//
// We're also sure to compare *paths*, not actual byte slices. The
// `source` stores paths which are normalized which may be different
// from the strings on the command line.
let source = self.cstore.used_crate_source(cnum);
if let Some(locs) = self.sess.opts.externs.get(name) {
let found = locs.iter().any(|l| {
let l = fs::canonicalize(l).ok();
source.dylib.as_ref().map(|p| &p.0) == l.as_ref() ||
source.rlib.as_ref().map(|p| &p.0) == l.as_ref()
});
if found {
ret = Some(cnum);
}
return
}
// Alright, so we've gotten this far which means that `data` has the
// right name, we don't have a hash, and we don't have a --extern
// pointing for ourselves. We're still not quite yet done because we
// have to make sure that this crate was found in the crate lookup
// path (this is a top-level dependency) as we don't want to
// implicitly load anything inside the dependency lookup path.
let prev_kind = source.dylib.as_ref().or(source.rlib.as_ref())
.unwrap().1;
if ret.is_none() && (prev_kind == kind || prev_kind == PathKind::All) {
ret = Some(cnum);
}
});
return ret;
}
fn verify_no_symbol_conflicts(&self,
span: Span,
metadata: &MetadataBlob) {
let disambiguator = decoder::get_crate_disambiguator(metadata.as_slice());
let crate_name = decoder::get_crate_name(metadata.as_slice());
// Check for (potential) conflicts with the local crate
if self.local_crate_name == crate_name &&
self.sess.local_crate_disambiguator() == disambiguator {
span_fatal!(self.sess, span, E0519,
"the current crate is indistinguishable from one of its \
dependencies: it has the same crate-name `{}` and was \
compiled with the same `-C metadata` arguments. This \
will result in symbol conflicts between the two.",
crate_name)
}
let svh = decoder::get_crate_hash(metadata.as_slice());
// Check for conflicts with any crate loaded so far
self.cstore.iter_crate_data(|_, other| {
if other.name() == crate_name && // same crate-name
other.disambiguator() == disambiguator && // same crate-disambiguator
other.hash() != svh { // but different SVH
span_fatal!(self.sess, span, E0523,
"found two different crates with name `{}` that are \
not distinguished by differing `-C metadata`. This \
will result in symbol conflicts between the two.",
crate_name)
}
});
}
fn register_crate(&mut self,
root: &Option<CratePaths>,
ident: &str,
name: &str,
span: Span,
lib: loader::Library,
explicitly_linked: bool)
-> (ast::CrateNum, Rc<cstore::CrateMetadata>,
cstore::CrateSource) {
info!("register crate `extern crate {} as {}`", name, ident);
self.verify_no_symbol_conflicts(span, &lib.metadata);
// Claim this crate number and cache it
let cnum = self.next_crate_num;
self.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().map(|p| p.0),
rlib: lib.rlib.clone().map(|p| p.0),
})
} else {
None
};
// Maintain a reference to the top most crate.
let root = if root.is_some() { root } else { &crate_paths };
let loader::Library { dylib, rlib, metadata } = lib;
let cnum_map = self.resolve_crate_deps(root, metadata.as_slice(), cnum, span);
let staged_api = self.is_staged_api(metadata.as_slice());
let cmeta = Rc::new(cstore::CrateMetadata {
name: name.to_string(),
extern_crate: Cell::new(None),
index: decoder::load_index(metadata.as_slice()),
xref_index: decoder::load_xrefs(metadata.as_slice()),
key_map: decoder::load_key_map(metadata.as_slice()),
data: metadata,
cnum_map: RefCell::new(cnum_map),
cnum: cnum,
codemap_import_info: RefCell::new(vec![]),
staged_api: staged_api,
explicitly_linked: Cell::new(explicitly_linked),
});
if decoder::get_derive_registrar_fn(cmeta.data.as_slice()).is_some() {
self.sess.span_err(span, "crates of the `rustc-macro` crate type \
cannot be linked at runtime");
}
let source = cstore::CrateSource {
dylib: dylib,
rlib: rlib,
cnum: cnum,
};
self.cstore.set_crate_data(cnum, cmeta.clone());
self.cstore.add_used_crate_source(source.clone());
(cnum, cmeta, source)
}
fn is_staged_api(&self, data: &[u8]) -> bool {
let attrs = decoder::get_crate_attributes(data);
for attr in &attrs {
if attr.name() == "stable" || attr.name() == "unstable" {
return true
}
}
false
}
fn resolve_crate(&mut self,
root: &Option<CratePaths>,
ident: &str,
name: &str,
hash: Option<&Svh>,
span: Span,
kind: PathKind,
explicitly_linked: bool)
-> (ast::CrateNum, Rc<cstore::CrateMetadata>, cstore::CrateSource) {
info!("resolving crate `extern crate {} as {}`", name, ident);
let result = match self.existing_match(name, hash, kind) {
Some(cnum) => LoadResult::Previous(cnum),
None => {
info!("falling back to a load");
let mut load_ctxt = loader::Context {
sess: self.sess,
span: span,
ident: ident,
crate_name: name,
hash: hash.map(|a| &*a),
filesearch: self.sess.target_filesearch(kind),
target: &self.sess.target.target,
triple: &self.sess.opts.target_triple,
root: root,
rejected_via_hash: vec!(),
rejected_via_triple: vec!(),
rejected_via_kind: vec!(),
rejected_via_version: vec!(),
should_match_name: true,
};
match self.load(&mut load_ctxt) {
Some(result) => result,
None => load_ctxt.report_load_errs(),
}
}
};
match result {
LoadResult::Previous(cnum) => {
let data = self.cstore.get_crate_data(cnum);
if explicitly_linked && !data.explicitly_linked.get() {
data.explicitly_linked.set(explicitly_linked);
}
(cnum, data, self.cstore.used_crate_source(cnum))
}
LoadResult::Loaded(library) => {
self.register_crate(root, ident, name, span, library,
explicitly_linked)
}
}
}
fn load(&mut self, loader: &mut loader::Context) -> Option<LoadResult> {
let library = match loader.maybe_load_library_crate() {
Some(lib) => lib,
None => return None,
};
// In the case that we're loading a crate, but not matching
// against a hash, we could load a crate which has the same hash
// as an already loaded crate. If this is the case prevent
// duplicates by just using the first crate.
//
// Note that we only do this for target triple crates, though, as we
// don't want to match a host crate against an equivalent target one
// already loaded.
if loader.triple == self.sess.opts.target_triple {
let meta_hash = decoder::get_crate_hash(library.metadata.as_slice());
let meta_name = decoder::get_crate_name(library.metadata.as_slice())
.to_string();
let mut result = LoadResult::Loaded(library);
self.cstore.iter_crate_data(|cnum, data| {
if data.name() == meta_name && meta_hash == data.hash() {
assert!(loader.hash.is_none());
info!("load success, going to previous cnum: {}", cnum);
result = LoadResult::Previous(cnum);
}
});
Some(result)
} else {
Some(LoadResult::Loaded(library))
}
}
fn update_extern_crate(&mut self,
cnum: ast::CrateNum,
mut extern_crate: ExternCrate,
visited: &mut FnvHashSet<(ast::CrateNum, bool)>)
{
if !visited.insert((cnum, extern_crate.direct)) { return }
let cmeta = self.cstore.get_crate_data(cnum);
let old_extern_crate = cmeta.extern_crate.get();
// Prefer:
// - something over nothing (tuple.0);
// - direct extern crate to indirect (tuple.1);
// - shorter paths to longer (tuple.2).
let new_rank = (true, extern_crate.direct, !extern_crate.path_len);
let old_rank = match old_extern_crate {
None => (false, false, !0),
Some(ref c) => (true, c.direct, !c.path_len),
};
if old_rank >= new_rank {
return; // no change needed
}
cmeta.extern_crate.set(Some(extern_crate));
// Propagate the extern crate info to dependencies.
extern_crate.direct = false;
for &dep_cnum in cmeta.cnum_map.borrow().iter() {
self.update_extern_crate(dep_cnum, extern_crate, visited);
}
}
// Go through the crate metadata and load any crates that it references
fn resolve_crate_deps(&mut self,
root: &Option<CratePaths>,
cdata: &[u8],
krate: ast::CrateNum,
span: Span)
-> cstore::CrateNumMap {
debug!("resolving deps of external crate");
// The map from crate numbers in the crate we're resolving to local crate
// numbers
let map: FnvHashMap<_, _> = decoder::get_crate_deps(cdata).iter().map(|dep| {
debug!("resolving dep crate {} hash: `{}`", dep.name, dep.hash);
let (local_cnum, ..) = self.resolve_crate(root,
&dep.name,
&dep.name,
Some(&dep.hash),
span,
PathKind::Dependency,
dep.explicitly_linked);
(dep.cnum, local_cnum)
}).collect();
let max_cnum = map.values().cloned().max().unwrap_or(0);
// we map 0 and all other holes in the map to our parent crate. The "additional"
// self-dependencies should be harmless.
(0..max_cnum+1).map(|cnum| map.get(&cnum).cloned().unwrap_or(krate)).collect()
}
fn read_extension_crate(&mut self, span: Span, info: &CrateInfo) -> ExtensionCrate {
info!("read extension crate {} `extern crate {} as {}` linked={}",
info.id, info.name, info.ident, info.should_link);
let target_triple = &self.sess.opts.target_triple[..];
let is_cross = target_triple != config::host_triple();
let mut should_link = info.should_link && !is_cross;
let mut target_only = false;
let ident = info.ident.clone();
let name = info.name.clone();
let mut load_ctxt = loader::Context {
sess: self.sess,
span: span,
ident: &ident[..],
crate_name: &name[..],
hash: None,
filesearch: self.sess.host_filesearch(PathKind::Crate),
target: &self.sess.host,
triple: config::host_triple(),
root: &None,
rejected_via_hash: vec!(),
rejected_via_triple: vec!(),
rejected_via_kind: vec!(),
rejected_via_version: vec!(),
should_match_name: true,
};
let library = self.load(&mut load_ctxt).or_else(|| {
if !is_cross {
return None
}
// Try loading from target crates. This will abort later if we
// try to load a plugin registrar function,
target_only = true;
should_link = info.should_link;
load_ctxt.target = &self.sess.target.target;
load_ctxt.triple = target_triple;
load_ctxt.filesearch = self.sess.target_filesearch(PathKind::Crate);
self.load(&mut load_ctxt)
});
let library = match library {
Some(l) => l,
None => load_ctxt.report_load_errs(),
};
let (dylib, metadata) = match library {
LoadResult::Previous(cnum) => {
let dylib = self.cstore.opt_used_crate_source(cnum).unwrap().dylib;
let data = self.cstore.get_crate_data(cnum);
(dylib, PMDSource::Registered(data))
}
LoadResult::Loaded(library) => {
let dylib = library.dylib.clone();
let metadata = PMDSource::Owned(library);
(dylib, metadata)
}
};
ExtensionCrate {
metadata: metadata,
dylib: dylib.map(|p| p.0),
target_only: target_only,
name: info.name.to_string(),
ident: info.ident.to_string(),
span: span,
should_link: should_link,
}
}
pub fn read_macros(&mut self, item: &ast::Item) -> Macros {
let ci = self.extract_crate_info(item).unwrap();
let ekrate = self.read_extension_crate(item.span, &ci);
let source_name = format!("<{} macros>", item.ident);
let mut ret = Macros {
macro_rules: Vec::new(),
custom_derive_registrar: None,
svh: decoder::get_crate_hash(ekrate.metadata.as_slice()),
dylib: None,
};
decoder::each_exported_macro(ekrate.metadata.as_slice(),
|name, attrs, span, body| {
// NB: Don't use parse::parse_tts_from_source_str because it parses with
// quote_depth > 0.
let mut p = parse::new_parser_from_source_str(&self.sess.parse_sess,
self.local_crate_config.clone(),
source_name.clone(),
body);
let lo = p.span.lo;
let body = match p.parse_all_token_trees() {
Ok(body) => body,
Err(mut err) => {
err.emit();
self.sess.abort_if_errors();
unreachable!();
}
};
let local_span = mk_sp(lo, p.last_span.hi);
// Mark the attrs as used
for attr in &attrs {
attr::mark_used(attr);
}
ret.macro_rules.push(ast::MacroDef {
ident: ast::Ident::with_empty_ctxt(name),
attrs: attrs,
id: ast::DUMMY_NODE_ID,
span: local_span,
imported_from: Some(item.ident),
// overridden in plugin/load.rs
export: false,
use_locally: false,
allow_internal_unstable: false,
body: body,
});
self.sess.imported_macro_spans.borrow_mut()
.insert(local_span, (name.as_str().to_string(), span));
true
});
match decoder::get_derive_registrar_fn(ekrate.metadata.as_slice()) {
Some(id) => ret.custom_derive_registrar = Some(id),
// If this crate is not a rustc-macro crate then we might be able to
// register it with the local crate store to prevent loading the
// metadata twice.
//
// If it's a rustc-macro crate, though, then we definitely don't
// want to register it with the local crate store as we're just
// going to use it as we would a plugin.
None => {
ekrate.register(self);
return ret
}
}
self.cstore.add_used_for_derive_macros(item);
ret.dylib = ekrate.dylib.clone();
if ret.dylib.is_none() {
span_bug!(item.span, "rustc-macro crate not dylib");
}
if ekrate.target_only {
let message = format!("rustc-macro crate is not available for \
triple `{}` (only found {})",
config::host_triple(),
self.sess.opts.target_triple);
self.sess.span_fatal(item.span, &message);
}
return ret
}
/// Look for a plugin registrar. Returns library path, crate
/// SVH and DefIndex of the registrar function.
pub fn find_plugin_registrar(&mut self, span: Span, name: &str)
-> Option<(PathBuf, Svh, DefIndex)> {
let ekrate = self.read_extension_crate(span, &CrateInfo {
name: name.to_string(),
ident: name.to_string(),
id: ast::DUMMY_NODE_ID,
should_link: false,
});
if ekrate.target_only {
// Need to abort before syntax expansion.
let message = format!("plugin `{}` is not available for triple `{}` \
(only found {})",
name,
config::host_triple(),
self.sess.opts.target_triple);
span_fatal!(self.sess, span, E0456, "{}", &message[..]);
}
let svh = decoder::get_crate_hash(ekrate.metadata.as_slice());
let registrar =
decoder::get_plugin_registrar_fn(ekrate.metadata.as_slice());
match (ekrate.dylib.as_ref(), registrar) {
(Some(dylib), Some(reg)) => {
Some((dylib.to_path_buf(), svh, reg))
}
(None, Some(_)) => {
span_err!(self.sess, span, E0457,
"plugin `{}` only found in rlib format, but must be available \
in dylib format",
name);
// No need to abort because the loading code will just ignore this
// empty dylib.
None
}
_ => None,
}
}
fn register_statically_included_foreign_items(&mut self) {
let libs = self.cstore.get_used_libraries();
for (lib, list) in self.foreign_item_map.iter() {
let is_static = libs.borrow().iter().any(|&(ref name, kind)| {
lib == name && kind == cstore::NativeStatic
});
if is_static {
for id in list {
self.cstore.add_statically_included_foreign_item(*id);
}
}
}
}
fn inject_panic_runtime(&mut self, krate: &ast::Crate) {
// If we're only compiling an rlib, then there's no need to select a
// panic runtime, so we just skip this section entirely.
let any_non_rlib = self.sess.crate_types.borrow().iter().any(|ct| {
*ct != config::CrateTypeRlib
});
if !any_non_rlib {
info!("panic runtime injection skipped, only generating rlib");
return
}
// If we need a panic runtime, we try to find an existing one here. At
// the same time we perform some general validation of the DAG we've got
// going such as ensuring everything has a compatible panic strategy.
//
// The logic for finding the panic runtime here is pretty much the same
// as the allocator case with the only addition that the panic strategy
// compilation mode also comes into play.
let desired_strategy = self.sess.opts.cg.panic.clone();
let mut runtime_found = false;
let mut needs_panic_runtime = attr::contains_name(&krate.attrs,
"needs_panic_runtime");
self.cstore.iter_crate_data(|cnum, data| {
needs_panic_runtime = needs_panic_runtime || data.needs_panic_runtime();
if data.is_panic_runtime() {
// Inject a dependency from all #![needs_panic_runtime] to this
// #![panic_runtime] crate.
self.inject_dependency_if(cnum, "a panic runtime",
&|data| data.needs_panic_runtime());
runtime_found = runtime_found || data.explicitly_linked.get();
}
});
// If an explicitly linked and matching panic runtime was found, or if
// we just don't need one at all, then we're done here and there's
// nothing else to do.
if !needs_panic_runtime || runtime_found {
return
}
// By this point we know that we (a) need a panic runtime and (b) no
// panic runtime was explicitly linked. Here we just load an appropriate
// default runtime for our panic strategy and then inject the
// dependencies.
//
// We may resolve to an already loaded crate (as the crate may not have
// been explicitly linked prior to this) and we may re-inject
// dependencies again, but both of those situations are fine.
//
// Also note that we have yet to perform validation of the crate graph
// in terms of everyone has a compatible panic runtime format, that's
// performed later as part of the `dependency_format` module.
let name = match desired_strategy {
PanicStrategy::Unwind => "panic_unwind",
PanicStrategy::Abort => "panic_abort",
};
info!("panic runtime not found -- loading {}", name);
let (cnum, data, _) = self.resolve_crate(&None, name, name, None,
syntax_pos::DUMMY_SP,
PathKind::Crate, false);
// Sanity check the loaded crate to ensure it is indeed a panic runtime
// and the panic strategy is indeed what we thought it was.
if !data.is_panic_runtime() {
self.sess.err(&format!("the crate `{}` is not a panic runtime",
name));
}
if data.panic_strategy() != desired_strategy {
self.sess.err(&format!("the crate `{}` does not have the panic \
strategy `{}`",
name, desired_strategy.desc()));
}
self.sess.injected_panic_runtime.set(Some(cnum));
self.inject_dependency_if(cnum, "a panic runtime",
&|data| data.needs_panic_runtime());
}
fn inject_allocator_crate(&mut self) {
// Make sure that we actually need an allocator, if none of our
// dependencies need one then we definitely don't!
//
// Also, if one of our dependencies has an explicit allocator, then we
// also bail out as we don't need to implicitly inject one.
let mut needs_allocator = false;
let mut found_required_allocator = false;
self.cstore.iter_crate_data(|cnum, data| {
needs_allocator = needs_allocator || data.needs_allocator();
if data.is_allocator() {
info!("{} required by rlib and is an allocator", data.name());
self.inject_dependency_if(cnum, "an allocator",
&|data| data.needs_allocator());
found_required_allocator = found_required_allocator ||
data.explicitly_linked.get();
}
});
if !needs_allocator || found_required_allocator { return }
// At this point we've determined that we need an allocator and no
// previous allocator has been activated. We look through our outputs of
// crate types to see what kind of allocator types we may need.
//
// The main special output type here is that rlibs do **not** need an
// allocator linked in (they're just object files), only final products
// (exes, dylibs, staticlibs) need allocators.
let mut need_lib_alloc = false;
let mut need_exe_alloc = false;
for ct in self.sess.crate_types.borrow().iter() {
match *ct {
config::CrateTypeExecutable => need_exe_alloc = true,
config::CrateTypeDylib |
config::CrateTypeRustcMacro |
config::CrateTypeCdylib |
config::CrateTypeStaticlib => need_lib_alloc = true,
config::CrateTypeRlib => {}
}
}
if !need_lib_alloc && !need_exe_alloc { return }
// The default allocator crate comes from the custom target spec, and we
// choose between the standard library allocator or exe allocator. This
// distinction exists because the default allocator for binaries (where
// the world is Rust) is different than library (where the world is
// likely *not* Rust).
//
// If a library is being produced, but we're also flagged with `-C
// prefer-dynamic`, then we interpret this as a *Rust* dynamic library
// is being produced so we use the exe allocator instead.
//
// What this boils down to is:
//
// * Binaries use jemalloc
// * Staticlibs and Rust dylibs use system malloc
// * Rust dylibs used as dependencies to rust use jemalloc
let name = if need_lib_alloc && !self.sess.opts.cg.prefer_dynamic {
&self.sess.target.target.options.lib_allocation_crate
} else {
&self.sess.target.target.options.exe_allocation_crate
};
let (cnum, data, _) = self.resolve_crate(&None, name, name, None,
syntax_pos::DUMMY_SP,
PathKind::Crate, false);
// Sanity check the crate we loaded to ensure that it is indeed an
// allocator.
if !data.is_allocator() {
self.sess.err(&format!("the allocator crate `{}` is not tagged \
with #![allocator]", data.name()));
}
self.sess.injected_allocator.set(Some(cnum));
self.inject_dependency_if(cnum, "an allocator",
&|data| data.needs_allocator());
}
fn inject_dependency_if(&self,
krate: ast::CrateNum,
what: &str,
needs_dep: &Fn(&cstore::CrateMetadata) -> bool) {
// don't perform this validation if the session has errors, as one of
// those errors may indicate a circular dependency which could cause
// this to stack overflow.
if self.sess.has_errors() {
return
}
// Before we inject any dependencies, make sure we don't inject a
// circular dependency by validating that this crate doesn't
// transitively depend on any crates satisfying `needs_dep`.
for dep in self.cstore.crate_dependencies_in_rpo(krate) {
let data = self.cstore.get_crate_data(dep);
if needs_dep(&data) {
self.sess.err(&format!("the crate `{}` cannot depend \
on a crate that needs {}, but \
it depends on `{}`",
self.cstore.get_crate_data(krate).name(),
what,
data.name()));
}
}
// All crates satisfying `needs_dep` do not explicitly depend on the
// crate provided for this compile, but in order for this compilation to
// be successfully linked we need to inject a dependency (to order the
// crates on the command line correctly).
self.cstore.iter_crate_data(|cnum, data| {
if !needs_dep(data) {
return
}
info!("injecting a dep from {} to {}", cnum, krate);
data.cnum_map.borrow_mut().push(krate);
});
}
}
impl ExtensionCrate {
fn register(self, creader: &mut CrateReader) {
if !self.should_link {
return
}
let library = match self.metadata {
PMDSource::Owned(lib) => lib,
PMDSource::Registered(_) => return,
};
// Register crate now to avoid double-reading metadata
creader.register_crate(&None,
&self.ident,
&self.name,
self.span,
library,
true);
}
}
impl<'a> LocalCrateReader<'a> {
fn new(sess: &'a Session,
cstore: &'a CStore,
defs: &'a hir_map::Definitions,
krate: &'a ast::Crate,
local_crate_name: &str)
-> LocalCrateReader<'a> {
LocalCrateReader {
sess: sess,
cstore: cstore,
creader: CrateReader::new(sess, cstore, local_crate_name, krate.config.clone()),
krate: krate,
definitions: defs,
}
}
// Traverses an AST, reading all the information about use'd crates and
// extern libraries necessary for later resolving, typechecking, linking,
// etc.
fn read_crates(&mut self, dep_graph: &DepGraph) {
let _task = dep_graph.in_task(DepNode::CrateReader);
self.process_crate(self.krate);
visit::walk_crate(self, self.krate);
self.creader.inject_allocator_crate();
self.creader.inject_panic_runtime(self.krate);
if log_enabled!(log::INFO) {
dump_crates(&self.cstore);
}
for &(ref name, kind) in &self.sess.opts.libs {
register_native_lib(self.sess, self.cstore, None, name.clone(), kind);
}
self.creader.register_statically_included_foreign_items();
}
fn process_crate(&self, c: &ast::Crate) {
for a in c.attrs.iter().filter(|m| m.name() == "link_args") {
if let Some(ref linkarg) = a.value_str() {
self.cstore.add_used_link_args(&linkarg);
}
}
}
fn process_item(&mut self, i: &ast::Item) {
match i.node {
ast::ItemKind::ExternCrate(_) => {
// If this `extern crate` item has `#[macro_use]` then we can
// safely skip it. These annotations were processed during macro
// expansion and are already loaded (if necessary) into our
// crate store.
//
// Note that it's important we *don't* fall through below as
// some `#[macro_use]` crate are explicitly not linked (e.g.
// macro crates) so we want to ensure we avoid `resolve_crate`
// with those.
if attr::contains_name(&i.attrs, "macro_use") {
if self.cstore.was_used_for_derive_macros(i) {
return
}
}
if let Some(info) = self.creader.extract_crate_info(i) {
if !info.should_link {
return;
}
let (cnum, ..) = self.creader.resolve_crate(&None,
&info.ident,
&info.name,
None,
i.span,
PathKind::Crate,
true);
let def_id = self.definitions.opt_local_def_id(i.id).unwrap();
let len = self.definitions.def_path(def_id.index).data.len();
self.creader.update_extern_crate(cnum,
ExternCrate {
def_id: def_id,
span: i.span,
direct: true,
path_len: len,
},
&mut FnvHashSet());
self.cstore.add_extern_mod_stmt_cnum(info.id, cnum);
}
}
ast::ItemKind::ForeignMod(ref fm) => self.process_foreign_mod(i, fm),
_ => { }
}
}
fn process_foreign_mod(&mut self, i: &ast::Item, fm: &ast::ForeignMod) {
if fm.abi == Abi::Rust || fm.abi == Abi::RustIntrinsic || fm.abi == Abi::PlatformIntrinsic {
return;
}
// First, add all of the custom #[link_args] attributes
for m in i.attrs.iter().filter(|a| a.check_name("link_args")) {
if let Some(linkarg) = m.value_str() {
self.cstore.add_used_link_args(&linkarg);
}
}
// Next, process all of the #[link(..)]-style arguments
for m in i.attrs.iter().filter(|a| a.check_name("link")) {
let items = match m.meta_item_list() {
Some(item) => item,
None => continue,
};
let kind = items.iter().find(|k| {
k.check_name("kind")
}).and_then(|a| a.value_str());
let kind = match kind.as_ref().map(|s| &s[..]) {
Some("static") => cstore::NativeStatic,
Some("dylib") => cstore::NativeUnknown,
Some("framework") => cstore::NativeFramework,
Some(k) => {
struct_span_err!(self.sess, m.span, E0458,
"unknown kind: `{}`", k)
.span_label(m.span, &format!("unknown kind")).emit();
cstore::NativeUnknown
}
None => cstore::NativeUnknown
};
let n = items.iter().find(|n| {
n.check_name("name")
}).and_then(|a| a.value_str());
let n = match n {
Some(n) => n,
None => {
struct_span_err!(self.sess, m.span, E0459,
"#[link(...)] specified without `name = \"foo\"`")
.span_label(m.span, &format!("missing `name` argument")).emit();
InternedString::new("foo")
}
};
register_native_lib(self.sess, self.cstore, Some(m.span), n.to_string(), kind);
}
// Finally, process the #[linked_from = "..."] attribute
for m in i.attrs.iter().filter(|a| a.check_name("linked_from")) {
let lib_name = match m.value_str() {
Some(name) => name,
None => continue,
};
let list = self.creader.foreign_item_map.entry(lib_name.to_string())
.or_insert(Vec::new());
list.extend(fm.items.iter().map(|it| it.id));
}
}
}
/// Traverses an AST, reading all the information about use'd crates and extern
/// libraries necessary for later resolving, typechecking, linking, etc.
pub fn read_local_crates(sess: & Session,
cstore: & CStore,
defs: & hir_map::Definitions,
krate: & ast::Crate,
local_crate_name: &str,
dep_graph: &DepGraph) {
LocalCrateReader::new(sess, cstore, defs, krate, local_crate_name).read_crates(dep_graph)
}
/// Imports the codemap from an external crate into the codemap of the crate
/// currently being compiled (the "local crate").
///
/// The import algorithm works analogous to how AST items are inlined from an
/// external crate's metadata:
/// For every FileMap in the external codemap an 'inline' copy is created in the
/// local codemap. The correspondence relation between external and local
/// FileMaps is recorded in the `ImportedFileMap` objects returned from this
/// function. When an item from an external crate is later inlined into this
/// crate, this correspondence information is used to translate the span
/// information of the inlined item so that it refers the correct positions in
/// the local codemap (see `astencode::DecodeContext::tr_span()`).
///
/// The import algorithm in the function below will reuse FileMaps already
/// existing in the local codemap. For example, even if the FileMap of some
/// source file of libstd gets imported many times, there will only ever be
/// one FileMap object for the corresponding file in the local codemap.
///
/// Note that imported FileMaps do not actually contain the source code of the
/// file they represent, just information about length, line breaks, and
/// multibyte characters. This information is enough to generate valid debuginfo
/// for items inlined from other crates.
pub fn import_codemap(local_codemap: &codemap::CodeMap,
metadata: &MetadataBlob)
-> Vec<cstore::ImportedFileMap> {
let external_codemap = decoder::get_imported_filemaps(metadata.as_slice());
let imported_filemaps = external_codemap.into_iter().map(|filemap_to_import| {
// Try to find an existing FileMap that can be reused for the filemap to
// be imported. A FileMap is reusable if it is exactly the same, just
// positioned at a different offset within the codemap.
let reusable_filemap = {
local_codemap.files
.borrow()
.iter()
.find(|fm| are_equal_modulo_startpos(&fm, &filemap_to_import))
.map(|rc| rc.clone())
};
match reusable_filemap {
Some(fm) => {
cstore::ImportedFileMap {
original_start_pos: filemap_to_import.start_pos,
original_end_pos: filemap_to_import.end_pos,
translated_filemap: fm
}
}
None => {
// We can't reuse an existing FileMap, so allocate a new one
// containing the information we need.
let syntax_pos::FileMap {
name,
abs_path,
start_pos,
end_pos,
lines,
multibyte_chars,
..
} = filemap_to_import;
let source_length = (end_pos - start_pos).to_usize();
// Translate line-start positions and multibyte character
// position into frame of reference local to file.
// `CodeMap::new_imported_filemap()` will then translate those
// coordinates to their new global frame of reference when the
// offset of the FileMap is known.
let mut lines = lines.into_inner();
for pos in &mut lines {
*pos = *pos - start_pos;
}
let mut multibyte_chars = multibyte_chars.into_inner();
for mbc in &mut multibyte_chars {
mbc.pos = mbc.pos - start_pos;
}
let local_version = local_codemap.new_imported_filemap(name,
abs_path,
source_length,
lines,
multibyte_chars);
cstore::ImportedFileMap {
original_start_pos: start_pos,
original_end_pos: end_pos,
translated_filemap: local_version
}
}
}
}).collect();
return imported_filemaps;
fn are_equal_modulo_startpos(fm1: &syntax_pos::FileMap,
fm2: &syntax_pos::FileMap)
-> bool {
if fm1.name != fm2.name {
return false;
}
let lines1 = fm1.lines.borrow();
let lines2 = fm2.lines.borrow();
if lines1.len() != lines2.len() {
return false;
}
for (&line1, &line2) in lines1.iter().zip(lines2.iter()) {
if (line1 - fm1.start_pos) != (line2 - fm2.start_pos) {
return false;
}
}
let multibytes1 = fm1.multibyte_chars.borrow();
let multibytes2 = fm2.multibyte_chars.borrow();
if multibytes1.len() != multibytes2.len() {
return false;
}
for (mb1, mb2) in multibytes1.iter().zip(multibytes2.iter()) {
if (mb1.bytes != mb2.bytes) ||
((mb1.pos - fm1.start_pos) != (mb2.pos - fm2.start_pos)) {
return false;
}
}
true
}
}