rust/src/librustc_metadata/creader.rs
2019-06-21 09:54:58 +02:00

1143 lines
45 KiB
Rust

//! Validates all used crates and extern libraries and loads their metadata
use crate::cstore::{self, CStore, CrateSource, MetadataBlob};
use crate::locator::{self, CratePaths};
use crate::decoder::proc_macro_def_path_table;
use crate::schema::CrateRoot;
use rustc_data_structures::sync::{Lrc, RwLock, Lock};
use rustc::hir::def_id::CrateNum;
use rustc_data_structures::svh::Svh;
use rustc::middle::allocator::AllocatorKind;
use rustc::middle::cstore::DepKind;
use rustc::mir::interpret::AllocDecodingState;
use rustc::session::{Session, CrateDisambiguator};
use rustc::session::config::{Sanitizer, self};
use rustc_target::spec::{PanicStrategy, TargetTriple};
use rustc::session::search_paths::PathKind;
use rustc::middle::cstore::{ExternCrate, ExternCrateSource};
use rustc::util::common::record_time;
use rustc::util::nodemap::FxHashSet;
use rustc::hir::map::Definitions;
use std::ops::Deref;
use std::path::PathBuf;
use std::{cmp, fs};
use syntax::ast;
use syntax::attr;
use syntax::ext::base::{SyntaxExtension, SyntaxExtensionKind};
use syntax::symbol::{Symbol, sym};
use syntax::visit;
use syntax::{span_err, span_fatal};
use syntax_pos::{Span, DUMMY_SP};
use log::{debug, info, log_enabled};
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,
local_crate_name: Symbol,
}
fn dump_crates(cstore: &CStore) {
info!("resolved crates:");
cstore.iter_crate_data(|_, data| {
info!(" name: {}", data.root.name);
info!(" cnum: {}", data.cnum);
info!(" hash: {}", data.root.hash);
info!(" reqd: {:?}", *data.dep_kind.lock());
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()));
});
}
// Extra info about a crate loaded for plugins or exported macros.
struct ExtensionCrate {
metadata: PMDSource,
dylib: Option<PathBuf>,
target_only: bool,
}
enum PMDSource {
Registered(Lrc<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),
}
enum LoadError<'a> {
LocatorError(locator::Context<'a>),
}
impl<'a> LoadError<'a> {
fn report(self) -> ! {
match self {
LoadError::LocatorError(locate_ctxt) => locate_ctxt.report_errs(),
}
}
}
impl<'a> CrateLoader<'a> {
pub fn new(sess: &'a Session, cstore: &'a CStore, local_crate_name: &str) -> Self {
CrateLoader {
sess,
cstore,
local_crate_name: Symbol::intern(local_crate_name),
}
}
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.root.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.get_crate_data(cnum).source;
if let Some(entry) = self.sess.opts.externs.get(&*name.as_str()) {
// Only use `--extern crate_name=path` here, not `--extern crate_name`.
let found = entry.locations.iter().filter_map(|l| l.as_ref()).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.root.name == root.name && // same crate-name
other.root.disambiguator == root.disambiguator && // same crate-disambiguator
other.root.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,
host_lib: Option<Library>,
root: &Option<CratePaths>,
ident: Symbol,
span: Span,
lib: Library,
dep_kind: DepKind,
name: Symbol
) -> (CrateNum, Lrc<cstore::CrateMetadata>) {
let crate_root = lib.metadata.get_root();
self.verify_no_symbol_conflicts(span, &crate_root);
let private_dep = self.sess.opts.externs.get(&name.as_str())
.map(|e| e.is_private_dep)
.unwrap_or(false);
info!("register crate `extern crate {} as {}` (private_dep = {})",
crate_root.name, ident, private_dep);
// Claim this crate number and cache it
let cnum = self.cstore.alloc_new_crate_num();
// 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 dependencies: Vec<CrateNum> = cnum_map.iter().cloned().collect();
let proc_macros = crate_root.proc_macro_decls_static.map(|_| {
if self.sess.opts.debugging_opts.dual_proc_macros {
let host_lib = host_lib.unwrap();
self.load_derive_macros(
&host_lib.metadata.get_root(),
host_lib.dylib.map(|p| p.0),
span
)
} else {
self.load_derive_macros(&crate_root, dylib.clone().map(|p| p.0), span)
}
});
let def_path_table = record_time(&self.sess.perf_stats.decode_def_path_tables_time, || {
if let Some(proc_macros) = &proc_macros {
proc_macro_def_path_table(&crate_root, proc_macros)
} else {
crate_root.def_path_table.decode((&metadata, self.sess))
}
});
let interpret_alloc_index: Vec<u32> = crate_root.interpret_alloc_index
.decode(&metadata)
.collect();
let trait_impls = crate_root
.impls
.decode((&metadata, self.sess))
.map(|trait_impls| (trait_impls.trait_id, trait_impls.impls))
.collect();
let cmeta = cstore::CrateMetadata {
name: crate_root.name,
imported_name: ident,
extern_crate: Lock::new(None),
def_path_table: Lrc::new(def_path_table),
trait_impls,
proc_macros,
root: crate_root,
blob: metadata,
cnum_map,
cnum,
dependencies: Lock::new(dependencies),
source_map_import_info: RwLock::new(vec![]),
alloc_decoding_state: AllocDecodingState::new(interpret_alloc_index),
dep_kind: Lock::new(dep_kind),
source: cstore::CrateSource {
dylib,
rlib,
rmeta,
},
private_dep
};
let cmeta = Lrc::new(cmeta);
self.cstore.set_crate_data(cnum, cmeta.clone());
(cnum, cmeta)
}
fn load_proc_macro<'b>(
&mut self,
locate_ctxt: &mut locator::Context<'b>,
path_kind: PathKind,
) -> Option<(LoadResult, Option<Library>)>
where
'a: 'b,
{
// Use a new locator Context so trying to load a proc macro doesn't affect the error
// message we emit
let mut proc_macro_locator = locate_ctxt.clone();
// Try to load a proc macro
proc_macro_locator.is_proc_macro = Some(true);
// Load the proc macro crate for the target
let (locator, target_result) = if self.sess.opts.debugging_opts.dual_proc_macros {
proc_macro_locator.reset();
let result = match self.load(&mut proc_macro_locator)? {
LoadResult::Previous(cnum) => return Some((LoadResult::Previous(cnum), None)),
LoadResult::Loaded(library) => Some(LoadResult::Loaded(library))
};
// Don't look for a matching hash when looking for the host crate.
// It won't be the same as the target crate hash
locate_ctxt.hash = None;
// Use the locate_ctxt when looking for the host proc macro crate, as that is required
// so we want it to affect the error message
(locate_ctxt, result)
} else {
(&mut proc_macro_locator, None)
};
// Load the proc macro crate for the host
locator.reset();
locator.is_proc_macro = Some(true);
locator.target = &self.sess.host;
locator.triple = TargetTriple::from_triple(config::host_triple());
locator.filesearch = self.sess.host_filesearch(path_kind);
let host_result = self.load(locator)?;
Some(if self.sess.opts.debugging_opts.dual_proc_macros {
let host_result = match host_result {
LoadResult::Previous(..) => {
panic!("host and target proc macros must be loaded in lock-step")
}
LoadResult::Loaded(library) => library
};
(target_result.unwrap(), Some(host_result))
} else {
(host_result, None)
})
}
fn resolve_crate<'b>(
&'b mut self,
root: &'b Option<CratePaths>,
ident: Symbol,
name: Symbol,
hash: Option<&'b Svh>,
extra_filename: Option<&'b str>,
span: Span,
path_kind: PathKind,
mut dep_kind: DepKind,
) -> Result<(CrateNum, Lrc<cstore::CrateMetadata>), LoadError<'b>> {
info!("resolving crate `extern crate {} as {}`", name, ident);
let result = if let Some(cnum) = self.existing_match(name, hash, path_kind) {
(LoadResult::Previous(cnum), None)
} else {
info!("falling back to a load");
let mut locate_ctxt = locator::Context {
sess: self.sess,
span,
ident,
crate_name: name,
hash,
extra_filename,
filesearch: self.sess.target_filesearch(path_kind),
target: &self.sess.target.target,
triple: self.sess.opts.target_triple.clone(),
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).map(|r| (r, None)).or_else(|| {
dep_kind = DepKind::UnexportedMacrosOnly;
self.load_proc_macro(&mut locate_ctxt, path_kind)
}).ok_or_else(move || LoadError::LocatorError(locate_ctxt))?
};
match result {
(LoadResult::Previous(cnum), None) => {
let data = self.cstore.get_crate_data(cnum);
if data.root.proc_macro_decls_static.is_some() {
dep_kind = DepKind::UnexportedMacrosOnly;
}
data.dep_kind.with_lock(|data_dep_kind| {
*data_dep_kind = cmp::max(*data_dep_kind, dep_kind);
});
Ok((cnum, data))
}
(LoadResult::Loaded(library), host_library) => {
Ok(self.register_crate(host_library, root, ident, span, library, dep_kind, name))
}
_ => panic!()
}
}
fn load(&mut self, locate_ctxt: &mut locator::Context<'_>) -> Option<LoadResult> {
let library = locate_ctxt.maybe_load_library_crate()?;
// 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.root.name == root.name && root.hash == data.root.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 mut old_extern_crate = cmeta.extern_crate.borrow_mut();
// 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,
cmp::Reverse(extern_crate.path_len),
);
let old_rank = match *old_extern_crate {
None => (false, false, cmp::Reverse(usize::max_value())),
Some(ref c) => (
true,
c.direct,
cmp::Reverse(c.path_len),
),
};
if old_rank >= new_rank {
return; // no change needed
}
*old_extern_crate = Some(extern_crate);
drop(old_extern_crate);
// Propagate the extern crate info to dependencies.
extern_crate.direct = false;
for &dep_cnum in cmeta.dependencies.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.proc_macro_decls_static.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
.decode(metadata)
.map(|dep| {
info!("resolving dep crate {} hash: `{}` extra filename: `{}`", dep.name, dep.hash,
dep.extra_filename);
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), Some(&dep.extra_filename), span,
PathKind::Dependency, dep_kind,
).unwrap_or_else(|err| err.report());
local_cnum
})).collect()
}
fn read_extension_crate(&mut self, span: Span, orig_name: Symbol, rename: Symbol)
-> ExtensionCrate {
info!("read extension crate `extern crate {} as {}`", orig_name, rename);
let target_triple = self.sess.opts.target_triple.clone();
let host_triple = TargetTriple::from_triple(config::host_triple());
let is_cross = target_triple != host_triple;
let mut target_only = false;
let mut locate_ctxt = locator::Context {
sess: self.sess,
span,
ident: orig_name,
crate_name: rename,
hash: None,
extra_filename: None,
filesearch: self.sess.host_filesearch(PathKind::Crate),
target: &self.sess.host,
triple: 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,
}
}
/// Loads 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, Lrc<SyntaxExtension>)> {
use std::{env, mem};
use crate::dynamic_lib::DynamicLibrary;
use proc_macro::bridge::client::ProcMacro;
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_proc_macro_decls_symbol(root.disambiguator);
let decls = unsafe {
let sym = match lib.symbol(&sym) {
Ok(f) => f,
Err(err) => self.sess.span_fatal(span, &err),
};
*(sym as *const &[ProcMacro])
};
let extensions = decls.iter().map(|&decl| {
let (name, kind, helper_attrs) = match decl {
ProcMacro::CustomDerive { trait_name, attributes, client } => {
let helper_attrs =
attributes.iter().cloned().map(Symbol::intern).collect::<Vec<_>>();
(
trait_name,
SyntaxExtensionKind::Derive(Box::new(ProcMacroDerive {
client, attrs: helper_attrs.clone()
})),
helper_attrs,
)
}
ProcMacro::Attr { name, client } => (
name, SyntaxExtensionKind::Attr(Box::new(AttrProcMacro { client })), Vec::new()
),
ProcMacro::Bang { name, client } => (
name, SyntaxExtensionKind::Bang(Box::new(BangProcMacro { client })), Vec::new()
)
};
(Symbol::intern(name), Lrc::new(SyntaxExtension {
helper_attrs,
..SyntaxExtension::default(kind, root.edition)
}))
}).collect();
// 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);
extensions
}
/// 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: Symbol)
-> Option<(PathBuf, CrateDisambiguator)> {
let ekrate = self.read_extension_crate(span, name, name);
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() {
Some(dylib) => {
Some((dylib.to_path_buf(), root.disambiguator))
}
None => {
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
}
}
}
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::CrateType::Rlib
});
if !any_non_rlib {
info!("panic runtime injection skipped, only generating rlib");
self.sess.injected_panic_runtime.set(None);
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,
sym::needs_panic_runtime);
self.cstore.iter_crate_data(|cnum, data| {
needs_panic_runtime = needs_panic_runtime ||
data.root.needs_panic_runtime;
if data.root.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.root.needs_panic_runtime);
runtime_found = runtime_found || *data.dep_kind.lock() == 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 {
self.sess.injected_panic_runtime.set(None);
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, None, DUMMY_SP, PathKind::Crate, dep_kind)
.unwrap_or_else(|err| err.report());
// 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.root.panic_runtime {
self.sess.err(&format!("the crate `{}` is not a panic runtime",
name));
}
if data.root.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.root.needs_panic_runtime);
}
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.opts.target_triple.triple()) {
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.opts.target_triple.triple() == "x86_64-unknown-linux-gnu" {
if !self.sess.crate_types.borrow().iter().all(|ct| {
match *ct {
// Link the runtime
config::CrateType::Staticlib |
config::CrateType::Executable => true,
// This crate will be compiled with the required
// instrumentation pass
config::CrateType::Rlib |
config::CrateType::Dylib |
config::CrateType::Cdylib =>
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::CrateType::Executable => true,
// This crate will be compiled with the required
// instrumentation pass
config::CrateType::Rlib => 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 == sym::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, None, DUMMY_SP,
PathKind::Crate, dep_kind)
.unwrap_or_else(|err| err.report());
// Sanity check the loaded crate to ensure it is indeed a sanitizer runtime
if !data.root.sanitizer_runtime {
self.sess.err(&format!("the crate `{}` is not a sanitizer runtime",
name));
}
} else {
self.sess.err("Must link std to be compiled with `-Z sanitizer`");
}
}
}
fn inject_profiler_runtime(&mut self) {
if self.sess.opts.debugging_opts.profile ||
self.sess.opts.cg.profile_generate.enabled()
{
info!("loading profiler");
let symbol = Symbol::intern("profiler_builtins");
let dep_kind = DepKind::Implicit;
let (_, data) =
self.resolve_crate(&None, symbol, symbol, None, None, DUMMY_SP,
PathKind::Crate, dep_kind)
.unwrap_or_else(|err| err.report());
// Sanity check the loaded crate to ensure it is indeed a profiler runtime
if !data.root.profiler_runtime {
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);
self.sess.has_global_allocator.set(has_global_allocator);
// 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,
sym::needs_allocator);
self.cstore.iter_crate_data(|_, data| {
needs_allocator = needs_allocator || data.root.needs_allocator;
});
if !needs_allocator {
self.sess.allocator_kind.set(None);
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 all_rlib = self.sess.crate_types.borrow()
.iter()
.all(|ct| {
match *ct {
config::CrateType::Rlib => true,
_ => false,
}
});
if all_rlib {
self.sess.allocator_kind.set(None);
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 mut global_allocator = if has_global_allocator {
Some(None)
} else {
None
};
self.cstore.iter_crate_data(|_, data| {
if !data.root.has_global_allocator {
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.root.name));
}
Some(None) => {
self.sess.err(&format!("the #[global_allocator] in this \
crate conflicts with global \
allocator in: {}", data.root.name));
}
None => global_allocator = Some(Some(data.root.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 our allocator request is typically fulfilled
// by the standard library, denoted by the `#![default_lib_allocator]`
// attribute.
let mut has_default = attr::contains_name(&krate.attrs, sym::default_lib_allocator);
self.cstore.iter_crate_data(|_, data| {
if data.root.has_default_lib_allocator {
has_default = true;
}
});
if !has_default {
self.sess.err("no global memory allocator found but one is \
required; link to std or \
add #[global_allocator] to a static item \
that implements the GlobalAlloc trait.");
}
self.sess.allocator_kind.set(Some(AllocatorKind::DefaultLib));
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, sym::global_allocator) {
self.0 = true;
}
visit::walk_item(self, i)
}
}
}
}
fn inject_dependency_if(&self,
krate: CrateNum,
what: &str,
needs_dep: &dyn 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).root.name,
what,
data.root.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.dependencies.borrow_mut().push(krate);
});
}
}
impl<'a> CrateLoader<'a> {
pub fn postprocess(&mut self, krate: &ast::Crate) {
self.inject_sanitizer_runtime();
self.inject_profiler_runtime();
self.inject_allocator_crate(krate);
self.inject_panic_runtime(krate);
if log_enabled!(log::Level::Info) {
dump_crates(&self.cstore);
}
}
pub fn process_extern_crate(
&mut self, item: &ast::Item, definitions: &Definitions,
) -> CrateNum {
match item.node {
ast::ItemKind::ExternCrate(orig_name) => {
debug!("resolving extern crate stmt. ident: {} orig_name: {:?}",
item.ident, orig_name);
let orig_name = match orig_name {
Some(orig_name) => {
crate::validate_crate_name(Some(self.sess), &orig_name.as_str(),
Some(item.span));
orig_name
}
None => item.ident.name,
};
let dep_kind = if attr::contains_name(&item.attrs, sym::no_link) {
DepKind::UnexportedMacrosOnly
} else {
DepKind::Explicit
};
let (cnum, ..) = self.resolve_crate(
&None, item.ident.name, orig_name, None, None,
item.span, PathKind::Crate, dep_kind,
).unwrap_or_else(|err| err.report());
let def_id = definitions.opt_local_def_id(item.id).unwrap();
let path_len = definitions.def_path(def_id.index).data.len();
self.update_extern_crate(
cnum,
ExternCrate {
src: ExternCrateSource::Extern(def_id),
span: item.span,
path_len,
direct: true,
},
&mut FxHashSet::default(),
);
self.cstore.add_extern_mod_stmt_cnum(item.id, cnum);
cnum
}
_ => bug!(),
}
}
pub fn process_path_extern(
&mut self,
name: Symbol,
span: Span,
) -> CrateNum {
let cnum = self.resolve_crate(
&None, name, name, None, None, span, PathKind::Crate, DepKind::Explicit
).unwrap_or_else(|err| err.report()).0;
self.update_extern_crate(
cnum,
ExternCrate {
src: ExternCrateSource::Path,
span,
// to have the least priority in `update_extern_crate`
path_len: usize::max_value(),
direct: true,
},
&mut FxHashSet::default(),
);
cnum
}
pub fn maybe_process_path_extern(
&mut self,
name: Symbol,
span: Span,
) -> Option<CrateNum> {
let cnum = self.resolve_crate(
&None, name, name, None, None, span, PathKind::Crate, DepKind::Explicit
).ok()?.0;
self.update_extern_crate(
cnum,
ExternCrate {
src: ExternCrateSource::Path,
span,
// to have the least priority in `update_extern_crate`
path_len: usize::max_value(),
direct: true,
},
&mut FxHashSet::default(),
);
Some(cnum)
}
}