rust/src/librustc_metadata/creader.rs
Zack M. Davis 1b6c9605e4 use field init shorthand EVERYWHERE
Like #43008 (f668999), but _much more aggressive_.
2017-08-15 15:29:17 -07:00

1329 lines
54 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.
//! Validates all used crates and extern libraries and loads their metadata
use cstore::{self, CStore, CrateSource, MetadataBlob};
use locator::{self, CratePaths};
use schema::{CrateRoot, Tracked};
use rustc::hir::def_id::{CrateNum, DefIndex};
use rustc::hir::svh::Svh;
use rustc::middle::allocator::AllocatorKind;
use rustc::middle::cstore::DepKind;
use rustc::session::Session;
use rustc::session::config::{Sanitizer, self};
use rustc_back::PanicStrategy;
use rustc::session::search_paths::PathKind;
use rustc::middle;
use rustc::middle::cstore::{CrateStore, validate_crate_name, ExternCrate};
use rustc::util::common::record_time;
use rustc::util::nodemap::FxHashSet;
use rustc::middle::cstore::NativeLibrary;
use rustc::hir::map::Definitions;
use std::cell::{RefCell, Cell};
use std::ops::Deref;
use std::path::PathBuf;
use std::rc::Rc;
use std::{cmp, fs};
use syntax::ast;
use syntax::abi::Abi;
use syntax::attr;
use syntax::ext::base::SyntaxExtension;
use syntax::feature_gate::{self, GateIssue};
use syntax::symbol::Symbol;
use syntax::visit;
use syntax_pos::{Span, DUMMY_SP};
use log;
pub struct Library {
pub dylib: Option<(PathBuf, PathKind)>,
pub rlib: Option<(PathBuf, PathKind)>,
pub rmeta: Option<(PathBuf, PathKind)>,
pub metadata: MetadataBlob,
}
pub struct CrateLoader<'a> {
pub sess: &'a Session,
cstore: &'a CStore,
next_crate_num: CrateNum,
local_crate_name: Symbol,
}
fn dump_crates(cstore: &CStore) {
info!("resolved crates:");
cstore.iter_crate_data(|_, data| {
info!(" name: {}", data.name());
info!(" cnum: {}", data.cnum);
info!(" hash: {}", data.hash());
info!(" reqd: {:?}", data.dep_kind.get());
let CrateSource { dylib, rlib, rmeta } = data.source.clone();
dylib.map(|dl| info!(" dylib: {}", dl.0.display()));
rlib.map(|rl| info!(" rlib: {}", rl.0.display()));
rmeta.map(|rl| info!(" rmeta: {}", rl.0.display()));
});
}
#[derive(Debug)]
struct ExternCrateInfo {
ident: Symbol,
name: Symbol,
id: ast::NodeId,
dep_kind: DepKind,
}
fn register_native_lib(sess: &Session,
cstore: &CStore,
span: Option<Span>,
lib: NativeLibrary) {
if lib.name.as_str().is_empty() {
match span {
Some(span) => {
struct_span_err!(sess, span, E0454,
"#[link(name = \"\")] given with empty name")
.span_label(span, "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 lib.kind == cstore::NativeFramework && !is_osx {
let msg = "native frameworks are only available on macOS targets";
match span {
Some(span) => span_err!(sess, span, E0455, "{}", msg),
None => sess.err(msg),
}
}
if lib.cfg.is_some() && !sess.features.borrow().link_cfg {
feature_gate::emit_feature_err(&sess.parse_sess,
"link_cfg",
span.unwrap(),
GateIssue::Language,
"is feature gated");
}
if lib.kind == cstore::NativeStaticNobundle && !sess.features.borrow().static_nobundle {
feature_gate::emit_feature_err(&sess.parse_sess,
"static_nobundle",
span.unwrap(),
GateIssue::Language,
"kind=\"static-nobundle\" is feature gated");
}
cstore.add_used_library(lib);
}
fn relevant_lib(sess: &Session, lib: &NativeLibrary) -> bool {
match lib.cfg {
Some(ref cfg) => attr::cfg_matches(cfg, &sess.parse_sess, None),
None => true,
}
}
// Extra info about a crate loaded for plugins or exported macros.
struct ExtensionCrate {
metadata: PMDSource,
dylib: Option<PathBuf>,
target_only: bool,
}
enum PMDSource {
Registered(Rc<cstore::CrateMetadata>),
Owned(Library),
}
impl Deref for PMDSource {
type Target = MetadataBlob;
fn deref(&self) -> &MetadataBlob {
match *self {
PMDSource::Registered(ref cmd) => &cmd.blob,
PMDSource::Owned(ref lib) => &lib.metadata
}
}
}
enum LoadResult {
Previous(CrateNum),
Loaded(Library),
}
impl<'a> CrateLoader<'a> {
pub fn new(sess: &'a Session, cstore: &'a CStore, local_crate_name: &str) -> Self {
CrateLoader {
sess,
cstore,
next_crate_num: cstore.next_crate_num(),
local_crate_name: Symbol::intern(local_crate_name),
}
}
fn extract_crate_info(&self, i: &ast::Item) -> Option<ExternCrateInfo> {
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
}
None => i.ident.name,
};
Some(ExternCrateInfo {
ident: i.ident.name,
name,
id: i.id,
dep_kind: if attr::contains_name(&i.attrs, "no_link") {
DepKind::UnexportedMacrosOnly
} else {
DepKind::Explicit
},
})
}
_ => None
}
}
fn existing_match(&self, name: Symbol, hash: Option<&Svh>, kind: PathKind)
-> Option<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.as_str()) {
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())
.or(source.rmeta.as_ref())
.expect("No sources for crate").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,
root: &CrateRoot) {
// Check for (potential) conflicts with the local crate
if self.local_crate_name == root.name &&
self.sess.local_crate_disambiguator() == root.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.",
root.name)
}
// Check for conflicts with any crate loaded so far
self.cstore.iter_crate_data(|_, other| {
if other.name() == root.name && // same crate-name
other.disambiguator() == root.disambiguator && // same crate-disambiguator
other.hash() != root.hash { // 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.",
root.name)
}
});
}
fn register_crate(&mut self,
root: &Option<CratePaths>,
ident: Symbol,
name: Symbol,
span: Span,
lib: Library,
dep_kind: DepKind)
-> (CrateNum, Rc<cstore::CrateMetadata>) {
info!("register crate `extern crate {} as {}`", name, ident);
let crate_root = lib.metadata.get_root();
self.verify_no_symbol_conflicts(span, &crate_root);
// Claim this crate number and cache it
let cnum = self.next_crate_num;
self.next_crate_num = CrateNum::from_u32(cnum.as_u32() + 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),
rmeta: lib.rmeta.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 Library { dylib, rlib, rmeta, metadata } = lib;
let cnum_map = self.resolve_crate_deps(root, &crate_root, &metadata, cnum, span, dep_kind);
let def_path_table = record_time(&self.sess.perf_stats.decode_def_path_tables_time, || {
crate_root.def_path_table.decode(&metadata)
});
let exported_symbols = crate_root.exported_symbols
.map(|x| x.decode(&metadata).collect());
let trait_impls = crate_root
.impls
.map(|impls| {
impls.decode(&metadata)
.map(|trait_impls| (trait_impls.trait_id, trait_impls.impls))
.collect()
});
let mut cmeta = cstore::CrateMetadata {
name,
extern_crate: Cell::new(None),
def_path_table: Rc::new(def_path_table),
exported_symbols,
trait_impls,
proc_macros: crate_root.macro_derive_registrar.map(|_| {
self.load_derive_macros(&crate_root, dylib.clone().map(|p| p.0), span)
}),
root: crate_root,
blob: metadata,
cnum_map: RefCell::new(cnum_map),
cnum,
codemap_import_info: RefCell::new(vec![]),
attribute_cache: RefCell::new([Vec::new(), Vec::new()]),
dep_kind: Cell::new(dep_kind),
source: cstore::CrateSource {
dylib,
rlib,
rmeta,
},
// Initialize this with an empty set. The field is populated below
// after we were able to deserialize its contents.
dllimport_foreign_items: Tracked::new(FxHashSet()),
};
let dllimports: Tracked<FxHashSet<_>> = cmeta
.root
.native_libraries
.map(|native_libraries| {
let native_libraries: Vec<_> = native_libraries.decode(&cmeta)
.collect();
native_libraries
.iter()
.filter(|lib| relevant_lib(self.sess, lib) &&
lib.kind == cstore::NativeLibraryKind::NativeUnknown)
.flat_map(|lib| lib.foreign_items.iter())
.map(|id| *id)
.collect()
});
cmeta.dllimport_foreign_items = dllimports;
let cmeta = Rc::new(cmeta);
self.cstore.set_crate_data(cnum, cmeta.clone());
(cnum, cmeta)
}
fn resolve_crate(&mut self,
root: &Option<CratePaths>,
ident: Symbol,
name: Symbol,
hash: Option<&Svh>,
span: Span,
path_kind: PathKind,
mut dep_kind: DepKind)
-> (CrateNum, Rc<cstore::CrateMetadata>) {
info!("resolving crate `extern crate {} as {}`", name, ident);
let result = if let Some(cnum) = self.existing_match(name, hash, path_kind) {
LoadResult::Previous(cnum)
} else {
info!("falling back to a load");
let mut locate_ctxt = locator::Context {
sess: self.sess,
span,
ident,
crate_name: name,
hash: hash.map(|a| &*a),
filesearch: self.sess.target_filesearch(path_kind),
target: &self.sess.target.target,
triple: &self.sess.opts.target_triple,
root,
rejected_via_hash: vec![],
rejected_via_triple: vec![],
rejected_via_kind: vec![],
rejected_via_version: vec![],
rejected_via_filename: vec![],
should_match_name: true,
is_proc_macro: Some(false),
metadata_loader: &*self.cstore.metadata_loader,
};
self.load(&mut locate_ctxt).or_else(|| {
dep_kind = DepKind::UnexportedMacrosOnly;
let mut proc_macro_locator = locator::Context {
target: &self.sess.host,
triple: config::host_triple(),
filesearch: self.sess.host_filesearch(path_kind),
rejected_via_hash: vec![],
rejected_via_triple: vec![],
rejected_via_kind: vec![],
rejected_via_version: vec![],
rejected_via_filename: vec![],
is_proc_macro: Some(true),
..locate_ctxt
};
self.load(&mut proc_macro_locator)
}).unwrap_or_else(|| locate_ctxt.report_errs())
};
match result {
LoadResult::Previous(cnum) => {
let data = self.cstore.get_crate_data(cnum);
if data.root.macro_derive_registrar.is_some() {
dep_kind = DepKind::UnexportedMacrosOnly;
}
data.dep_kind.set(cmp::max(data.dep_kind.get(), dep_kind));
(cnum, data)
}
LoadResult::Loaded(library) => {
self.register_crate(root, ident, name, span, library, dep_kind)
}
}
}
fn load(&mut self, locate_ctxt: &mut locator::Context) -> Option<LoadResult> {
let library = match locate_ctxt.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.
let root = library.metadata.get_root();
if locate_ctxt.triple == self.sess.opts.target_triple {
let mut result = LoadResult::Loaded(library);
self.cstore.iter_crate_data(|cnum, data| {
if data.name() == root.name && root.hash == data.hash() {
assert!(locate_ctxt.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: CrateNum,
mut extern_crate: ExternCrate,
visited: &mut FxHashSet<(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>,
crate_root: &CrateRoot,
metadata: &MetadataBlob,
krate: CrateNum,
span: Span,
dep_kind: DepKind)
-> cstore::CrateNumMap {
debug!("resolving deps of external crate");
if crate_root.macro_derive_registrar.is_some() {
return cstore::CrateNumMap::new();
}
// The map from crate numbers in the crate we're resolving to local crate numbers.
// We map 0 and all other holes in the map to our parent crate. The "additional"
// self-dependencies should be harmless.
::std::iter::once(krate).chain(crate_root.crate_deps
.get_untracked()
.decode(metadata)
.map(|dep| {
debug!("resolving dep crate {} hash: `{}`", dep.name, dep.hash);
if dep.kind == DepKind::UnexportedMacrosOnly {
return krate;
}
let dep_kind = match dep_kind {
DepKind::MacrosOnly => DepKind::MacrosOnly,
_ => dep.kind,
};
let (local_cnum, ..) = self.resolve_crate(
root, dep.name, dep.name, Some(&dep.hash), span, PathKind::Dependency, dep_kind,
);
local_cnum
})).collect()
}
fn read_extension_crate(&mut self, span: Span, info: &ExternCrateInfo) -> ExtensionCrate {
info!("read extension crate {} `extern crate {} as {}` dep_kind={:?}",
info.id, info.name, info.ident, info.dep_kind);
let target_triple = &self.sess.opts.target_triple[..];
let is_cross = target_triple != config::host_triple();
let mut target_only = false;
let mut locate_ctxt = locator::Context {
sess: self.sess,
span,
ident: info.ident,
crate_name: info.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![],
rejected_via_filename: vec![],
should_match_name: true,
is_proc_macro: None,
metadata_loader: &*self.cstore.metadata_loader,
};
let library = self.load(&mut locate_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;
locate_ctxt.target = &self.sess.target.target;
locate_ctxt.triple = target_triple;
locate_ctxt.filesearch = self.sess.target_filesearch(PathKind::Crate);
self.load(&mut locate_ctxt)
});
let library = match library {
Some(l) => l,
None => locate_ctxt.report_errs(),
};
let (dylib, metadata) = match library {
LoadResult::Previous(cnum) => {
let data = self.cstore.get_crate_data(cnum);
(data.source.dylib.clone(), PMDSource::Registered(data))
}
LoadResult::Loaded(library) => {
let dylib = library.dylib.clone();
let metadata = PMDSource::Owned(library);
(dylib, metadata)
}
};
ExtensionCrate {
metadata,
dylib: dylib.map(|p| p.0),
target_only,
}
}
/// Load custom derive macros.
///
/// Note that this is intentionally similar to how we load plugins today,
/// but also intentionally separate. Plugins are likely always going to be
/// implemented as dynamic libraries, but we have a possible future where
/// custom derive (and other macro-1.1 style features) are implemented via
/// executables and custom IPC.
fn load_derive_macros(&mut self, root: &CrateRoot, dylib: Option<PathBuf>, span: Span)
-> Vec<(ast::Name, Rc<SyntaxExtension>)> {
use std::{env, mem};
use proc_macro::TokenStream;
use proc_macro::__internal::Registry;
use rustc_back::dynamic_lib::DynamicLibrary;
use syntax_ext::deriving::custom::ProcMacroDerive;
use syntax_ext::proc_macro_impl::{AttrProcMacro, BangProcMacro};
let path = match dylib {
Some(dylib) => dylib,
None => span_bug!(span, "proc-macro crate not dylib"),
};
// Make sure the path contains a / or the linker will search for it.
let path = env::current_dir().unwrap().join(path);
let lib = match DynamicLibrary::open(Some(&path)) {
Ok(lib) => lib,
Err(err) => self.sess.span_fatal(span, &err),
};
let sym = self.sess.generate_derive_registrar_symbol(root.disambiguator,
root.macro_derive_registrar.unwrap());
let registrar = unsafe {
let sym = match lib.symbol(&sym) {
Ok(f) => f,
Err(err) => self.sess.span_fatal(span, &err),
};
mem::transmute::<*mut u8, fn(&mut Registry)>(sym)
};
struct MyRegistrar(Vec<(ast::Name, Rc<SyntaxExtension>)>);
impl Registry for MyRegistrar {
fn register_custom_derive(&mut self,
trait_name: &str,
expand: fn(TokenStream) -> TokenStream,
attributes: &[&'static str]) {
let attrs = attributes.iter().cloned().map(Symbol::intern).collect::<Vec<_>>();
let derive = ProcMacroDerive::new(expand, attrs.clone());
let derive = SyntaxExtension::ProcMacroDerive(Box::new(derive), attrs);
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)));
}
fn register_bang_proc_macro(&mut self,
name: &str,
expand: fn(TokenStream) -> TokenStream) {
let expand = SyntaxExtension::ProcMacro(
Box::new(BangProcMacro { inner: expand })
);
self.0.push((Symbol::intern(name), Rc::new(expand)));
}
}
let mut my_registrar = MyRegistrar(Vec::new());
registrar(&mut my_registrar);
// Intentionally leak the dynamic library. We can't ever unload it
// since the library can make things that will live arbitrarily long.
mem::forget(lib);
my_registrar.0
}
/// 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, Symbol, DefIndex)> {
let ekrate = self.read_extension_crate(span, &ExternCrateInfo {
name: Symbol::intern(name),
ident: Symbol::intern(name),
id: ast::DUMMY_NODE_ID,
dep_kind: DepKind::UnexportedMacrosOnly,
});
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 root = ekrate.metadata.get_root();
match (ekrate.dylib.as_ref(), root.plugin_registrar_fn) {
(Some(dylib), Some(reg)) => {
Some((dylib.to_path_buf(), root.disambiguator, 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 get_foreign_items_of_kind(&self, kind: cstore::NativeLibraryKind) -> Vec<DefIndex> {
let mut items = vec![];
let libs = self.cstore.get_used_libraries();
for lib in libs.borrow().iter() {
if relevant_lib(self.sess, lib) && lib.kind == kind {
items.extend(&lib.foreign_items);
}
}
items
}
fn register_statically_included_foreign_items(&mut self) {
for id in self.get_foreign_items_of_kind(cstore::NativeStatic) {
self.cstore.add_statically_included_foreign_item(id);
}
for id in self.get_foreign_items_of_kind(cstore::NativeStaticNobundle) {
self.cstore.add_statically_included_foreign_item(id);
}
}
fn register_dllimport_foreign_items(&mut self) {
let mut dllimports = self.cstore.dllimport_foreign_items.borrow_mut();
for id in self.get_foreign_items_of_kind(cstore::NativeUnknown) {
dllimports.insert(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.panic_strategy();
let mut runtime_found = false;
let mut needs_panic_runtime = attr::contains_name(&krate.attrs,
"needs_panic_runtime");
let dep_graph = &self.sess.dep_graph;
self.cstore.iter_crate_data(|cnum, data| {
needs_panic_runtime = needs_panic_runtime ||
data.needs_panic_runtime(dep_graph);
if data.is_panic_runtime(dep_graph) {
// 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(dep_graph));
runtime_found = runtime_found || data.dep_kind.get() == DepKind::Explicit;
}
});
// 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 => Symbol::intern("panic_unwind"),
PanicStrategy::Abort => Symbol::intern("panic_abort"),
};
info!("panic runtime not found -- loading {}", name);
let dep_kind = DepKind::Implicit;
let (cnum, data) =
self.resolve_crate(&None, name, name, None, DUMMY_SP, PathKind::Crate, dep_kind);
// 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(dep_graph) {
self.sess.err(&format!("the crate `{}` is not a panic runtime",
name));
}
if data.panic_strategy(dep_graph) != 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(dep_graph));
}
fn inject_sanitizer_runtime(&mut self) {
if let Some(ref sanitizer) = self.sess.opts.debugging_opts.sanitizer {
// Sanitizers can only be used on some tested platforms with
// executables linked to `std`
const ASAN_SUPPORTED_TARGETS: &[&str] = &["x86_64-unknown-linux-gnu",
"x86_64-apple-darwin"];
const TSAN_SUPPORTED_TARGETS: &[&str] = &["x86_64-unknown-linux-gnu",
"x86_64-apple-darwin"];
const LSAN_SUPPORTED_TARGETS: &[&str] = &["x86_64-unknown-linux-gnu"];
const MSAN_SUPPORTED_TARGETS: &[&str] = &["x86_64-unknown-linux-gnu"];
let supported_targets = match *sanitizer {
Sanitizer::Address => ASAN_SUPPORTED_TARGETS,
Sanitizer::Thread => TSAN_SUPPORTED_TARGETS,
Sanitizer::Leak => LSAN_SUPPORTED_TARGETS,
Sanitizer::Memory => MSAN_SUPPORTED_TARGETS,
};
if !supported_targets.contains(&&*self.sess.target.target.llvm_target) {
self.sess.err(&format!("{:?}Sanitizer only works with the `{}` target",
sanitizer,
supported_targets.join("` or `")
));
return
}
// firstyear 2017 - during testing I was unable to access an OSX machine
// to make this work on different crate types. As a result, today I have
// only been able to test and support linux as a target.
if self.sess.target.target.llvm_target == "x86_64-unknown-linux-gnu" {
if !self.sess.crate_types.borrow().iter().all(|ct| {
match *ct {
// Link the runtime
config::CrateTypeStaticlib |
config::CrateTypeExecutable => true,
// This crate will be compiled with the required
// instrumentation pass
config::CrateTypeRlib |
config::CrateTypeDylib |
config::CrateTypeCdylib =>
false,
_ => {
self.sess.err(&format!("Only executables, staticlibs, \
cdylibs, dylibs and rlibs can be compiled with \
`-Z sanitizer`"));
false
}
}
}) {
return
}
} else {
if !self.sess.crate_types.borrow().iter().all(|ct| {
match *ct {
// Link the runtime
config::CrateTypeExecutable => true,
// This crate will be compiled with the required
// instrumentation pass
config::CrateTypeRlib => false,
_ => {
self.sess.err(&format!("Only executables and rlibs can be \
compiled with `-Z sanitizer`"));
false
}
}
}) {
return
}
}
let mut uses_std = false;
self.cstore.iter_crate_data(|_, data| {
if data.name == "std" {
uses_std = true;
}
});
if uses_std {
let name = match *sanitizer {
Sanitizer::Address => "rustc_asan",
Sanitizer::Leak => "rustc_lsan",
Sanitizer::Memory => "rustc_msan",
Sanitizer::Thread => "rustc_tsan",
};
info!("loading sanitizer: {}", name);
let symbol = Symbol::intern(name);
let dep_kind = DepKind::Explicit;
let (_, data) =
self.resolve_crate(&None, symbol, symbol, None, DUMMY_SP,
PathKind::Crate, dep_kind);
// Sanity check the loaded crate to ensure it is indeed a sanitizer runtime
if !data.is_sanitizer_runtime(&self.sess.dep_graph) {
self.sess.err(&format!("the crate `{}` is not a sanitizer runtime",
name));
}
} else {
self.sess.err(&format!("Must link std to be compiled with `-Z sanitizer`"));
}
}
}
fn inject_profiler_runtime(&mut self) {
if self.sess.opts.debugging_opts.profile {
info!("loading profiler");
let symbol = Symbol::intern("profiler_builtins");
let dep_kind = DepKind::Implicit;
let (_, data) =
self.resolve_crate(&None, symbol, symbol, None, DUMMY_SP,
PathKind::Crate, dep_kind);
// Sanity check the loaded crate to ensure it is indeed a profiler runtime
if !data.is_profiler_runtime(&self.sess.dep_graph) {
self.sess.err(&format!("the crate `profiler_builtins` is not \
a profiler runtime"));
}
}
}
fn inject_allocator_crate(&mut self, krate: &ast::Crate) {
let has_global_allocator = has_global_allocator(krate);
if has_global_allocator {
self.sess.has_global_allocator.set(true);
}
// Check to see if we actually need an allocator. This desire comes
// about through the `#![needs_allocator]` attribute and is typically
// written down in liballoc.
let mut needs_allocator = attr::contains_name(&krate.attrs,
"needs_allocator");
let dep_graph = &self.sess.dep_graph;
self.cstore.iter_crate_data(|_, data| {
needs_allocator = needs_allocator || data.needs_allocator(dep_graph);
});
if !needs_allocator {
return
}
// At this point we've determined that we need an allocator. Let's see
// if our compilation session actually needs an allocator based on what
// we're emitting.
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::CrateTypeProcMacro |
config::CrateTypeCdylib |
config::CrateTypeStaticlib => need_lib_alloc = true,
config::CrateTypeRlib => {}
}
}
if !need_lib_alloc && !need_exe_alloc {
return
}
// Ok, we need an allocator. Not only that but we're actually going to
// create an artifact that needs one linked in. Let's go find the one
// that we're going to link in.
//
// First up we check for global allocators. Look at the crate graph here
// and see what's a global allocator, including if we ourselves are a
// global allocator.
let dep_graph = &self.sess.dep_graph;
let mut global_allocator = if has_global_allocator {
Some(None)
} else {
None
};
self.cstore.iter_crate_data(|_, data| {
if !data.has_global_allocator(dep_graph) {
return
}
match global_allocator {
Some(Some(other_crate)) => {
self.sess.err(&format!("the #[global_allocator] in {} \
conflicts with this global \
allocator in: {}",
other_crate,
data.name()));
}
Some(None) => {
self.sess.err(&format!("the #[global_allocator] in this \
crate conflicts with global \
allocator in: {}", data.name()));
}
None => global_allocator = Some(Some(data.name())),
}
});
if global_allocator.is_some() {
self.sess.allocator_kind.set(Some(AllocatorKind::Global));
return
}
// Ok we haven't found a global allocator but we still need an
// allocator. At this point we'll either fall back to the "library
// allocator" or the "exe allocator" depending on a few variables. Let's
// figure out which one.
//
// Note that here we favor linking to the "library allocator" as much as
// possible. If we're not creating rustc's version of libstd
// (need_lib_alloc and prefer_dynamic) then we select `None`, and if the
// exe allocation crate doesn't exist for this target then we also
// select `None`.
let exe_allocation_crate =
if need_lib_alloc && !self.sess.opts.cg.prefer_dynamic {
None
} else {
self.sess.target.target.options.exe_allocation_crate.as_ref()
};
match exe_allocation_crate {
// We've determined that we're injecting an "exe allocator" which
// means that we're going to load up a whole new crate. An example
// of this is that we're producing a normal binary on Linux which
// means we need to load the `alloc_jemalloc` crate to link as an
// allocator.
Some(krate) => {
self.sess.allocator_kind.set(Some(AllocatorKind::DefaultExe));
let name = Symbol::intern(krate);
let dep_kind = DepKind::Implicit;
let (cnum, _data) =
self.resolve_crate(&None,
name,
name,
None,
DUMMY_SP,
PathKind::Crate, dep_kind);
self.sess.injected_allocator.set(Some(cnum));
// self.cstore.iter_crate_data(|_, data| {
// if !data.needs_allocator(dep_graph) {
// return
// }
// data.cnum_map.borrow_mut().push(cnum);
// });
}
// We're not actually going to inject an allocator, we're going to
// require that something in our crate graph is the default lib
// allocator. This is typically libstd, so this'll rarely be an
// error.
None => {
self.sess.allocator_kind.set(Some(AllocatorKind::DefaultLib));
let mut found_lib_allocator =
attr::contains_name(&krate.attrs, "default_lib_allocator");
self.cstore.iter_crate_data(|_, data| {
if !found_lib_allocator {
if data.has_default_lib_allocator(dep_graph) {
found_lib_allocator = true;
}
}
});
if found_lib_allocator {
return
}
self.sess.err("no #[default_lib_allocator] found but one is \
required; is libstd not linked?");
}
}
fn has_global_allocator(krate: &ast::Crate) -> bool {
struct Finder(bool);
let mut f = Finder(false);
visit::walk_crate(&mut f, krate);
return f.0;
impl<'ast> visit::Visitor<'ast> for Finder {
fn visit_item(&mut self, i: &'ast ast::Item) {
if attr::contains_name(&i.attrs, "global_allocator") {
self.0 = true;
}
visit::walk_item(self, i)
}
}
}
}
fn inject_dependency_if(&self,
krate: 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<'a> CrateLoader<'a> {
pub fn preprocess(&mut self, krate: &ast::Crate) {
for attr in &krate.attrs {
if attr.path == "link_args" {
if let Some(linkarg) = attr.value_str() {
self.cstore.add_used_link_args(&linkarg.as_str());
}
}
}
}
fn process_foreign_mod(&mut self, i: &ast::Item, fm: &ast::ForeignMod,
definitions: &Definitions) {
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.as_str());
}
}
// 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()).map(Symbol::as_str);
let kind = match kind.as_ref().map(|s| &s[..]) {
Some("static") => cstore::NativeStatic,
Some("static-nobundle") => cstore::NativeStaticNobundle,
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, "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, "missing `name` argument").emit();
Symbol::intern("foo")
}
};
let cfg = items.iter().find(|k| {
k.check_name("cfg")
}).and_then(|a| a.meta_item_list());
let cfg = cfg.map(|list| {
list[0].meta_item().unwrap().clone()
});
let foreign_items = fm.items.iter()
.map(|it| definitions.opt_def_index(it.id).unwrap())
.collect();
let lib = NativeLibrary {
name: n,
kind,
cfg,
foreign_items,
};
register_native_lib(self.sess, self.cstore, Some(m.span), lib);
}
}
}
impl<'a> middle::cstore::CrateLoader for CrateLoader<'a> {
fn postprocess(&mut self, krate: &ast::Crate) {
// inject the sanitizer runtime before the allocator runtime because all
// sanitizers force the use of the `alloc_system` allocator
self.inject_sanitizer_runtime();
self.inject_profiler_runtime();
self.inject_allocator_crate(krate);
self.inject_panic_runtime(krate);
if log_enabled!(log::LogLevel::Info) {
dump_crates(&self.cstore);
}
// Process libs passed on the command line
// First, check for errors
let mut renames = FxHashSet();
for &(ref name, ref new_name, _) in &self.sess.opts.libs {
if let &Some(ref new_name) = new_name {
if new_name.is_empty() {
self.sess.err(
&format!("an empty renaming target was specified for library `{}`",name));
} else if !self.cstore.get_used_libraries().borrow().iter()
.any(|lib| lib.name == name as &str) {
self.sess.err(&format!("renaming of the library `{}` was specified, \
however this crate contains no #[link(...)] \
attributes referencing this library.", name));
} else if renames.contains(name) {
self.sess.err(&format!("multiple renamings were specified for library `{}` .",
name));
} else {
renames.insert(name);
}
}
}
// Update kind and, optionally, the name of all native libaries
// (there may be more than one) with the specified name.
for &(ref name, ref new_name, kind) in &self.sess.opts.libs {
let mut found = false;
for lib in self.cstore.get_used_libraries().borrow_mut().iter_mut() {
if lib.name == name as &str {
let mut changed = false;
if let Some(k) = kind {
lib.kind = k;
changed = true;
}
if let &Some(ref new_name) = new_name {
lib.name = Symbol::intern(new_name);
changed = true;
}
if !changed {
self.sess.warn(&format!("redundant linker flag specified for library `{}`",
name));
}
found = true;
}
}
if !found {
// Add if not found
let new_name = new_name.as_ref().map(|s| &**s); // &Option<String> -> Option<&str>
let lib = NativeLibrary {
name: Symbol::intern(new_name.unwrap_or(name)),
kind: if let Some(k) = kind { k } else { cstore::NativeUnknown },
cfg: None,
foreign_items: Vec::new(),
};
register_native_lib(self.sess, self.cstore, None, lib);
}
}
self.register_statically_included_foreign_items();
self.register_dllimport_foreign_items();
}
fn process_item(&mut self, item: &ast::Item, definitions: &Definitions) {
match item.node {
ast::ItemKind::ForeignMod(ref fm) => {
self.process_foreign_mod(item, fm, definitions)
},
ast::ItemKind::ExternCrate(_) => {
let info = self.extract_crate_info(item).unwrap();
let (cnum, ..) = self.resolve_crate(
&None, info.ident, info.name, None, item.span, PathKind::Crate, info.dep_kind,
);
let def_id = definitions.opt_local_def_id(item.id).unwrap();
let len = definitions.def_path(def_id.index).data.len();
let extern_crate =
ExternCrate { def_id: def_id, span: item.span, direct: true, path_len: len };
self.update_extern_crate(cnum, extern_crate, &mut FxHashSet());
self.cstore.add_extern_mod_stmt_cnum(info.id, cnum);
}
_ => {}
}
}
}