rust/compiler/rustc_metadata/src/native_libs.rs
2021-11-07 16:59:05 +01:00

445 lines
18 KiB
Rust

use rustc_attr as attr;
use rustc_data_structures::fx::FxHashSet;
use rustc_errors::struct_span_err;
use rustc_hir as hir;
use rustc_hir::itemlikevisit::ItemLikeVisitor;
use rustc_middle::ty::{List, ParamEnv, ParamEnvAnd, Ty, TyCtxt};
use rustc_session::cstore::{DllCallingConvention, DllImport, NativeLib};
use rustc_session::parse::feature_err;
use rustc_session::utils::NativeLibKind;
use rustc_session::Session;
use rustc_span::symbol::{kw, sym, Symbol};
use rustc_span::Span;
use rustc_target::spec::abi::Abi;
crate fn collect(tcx: TyCtxt<'_>) -> Vec<NativeLib> {
let mut collector = Collector { tcx, libs: Vec::new() };
tcx.hir().visit_all_item_likes(&mut collector);
collector.process_command_line();
collector.libs
}
crate fn relevant_lib(sess: &Session, lib: &NativeLib) -> bool {
match lib.cfg {
Some(ref cfg) => attr::cfg_matches(cfg, &sess.parse_sess, None),
None => true,
}
}
struct Collector<'tcx> {
tcx: TyCtxt<'tcx>,
libs: Vec<NativeLib>,
}
impl ItemLikeVisitor<'tcx> for Collector<'tcx> {
fn visit_item(&mut self, it: &'tcx hir::Item<'tcx>) {
let (abi, foreign_mod_items) = match it.kind {
hir::ItemKind::ForeignMod { abi, items } => (abi, items),
_ => return,
};
if abi == Abi::Rust || abi == Abi::RustIntrinsic || abi == Abi::PlatformIntrinsic {
return;
}
// Process all of the #[link(..)]-style arguments
let sess = &self.tcx.sess;
for m in self.tcx.hir().attrs(it.hir_id()).iter().filter(|a| a.has_name(sym::link)) {
let items = match m.meta_item_list() {
Some(item) => item,
None => continue,
};
let mut lib = NativeLib {
name: None,
kind: NativeLibKind::Unspecified,
cfg: None,
foreign_module: Some(it.def_id.to_def_id()),
wasm_import_module: None,
verbatim: None,
dll_imports: Vec::new(),
};
let mut kind_specified = false;
for item in items.iter() {
if item.has_name(sym::kind) {
kind_specified = true;
let kind = match item.value_str() {
Some(name) => name,
None => continue, // skip like historical compilers
};
lib.kind = match &*kind.as_str() {
"static" => NativeLibKind::Static { bundle: None, whole_archive: None },
"static-nobundle" => {
sess.struct_span_warn(
item.span(),
"library kind `static-nobundle` has been superseded by specifying \
modifier `-bundle` with library kind `static`",
)
.emit();
if !self.tcx.features().static_nobundle {
feature_err(
&self.tcx.sess.parse_sess,
sym::static_nobundle,
item.span(),
"kind=\"static-nobundle\" is unstable",
)
.emit();
}
NativeLibKind::Static { bundle: Some(false), whole_archive: None }
}
"dylib" => NativeLibKind::Dylib { as_needed: None },
"framework" => NativeLibKind::Framework { as_needed: None },
"raw-dylib" => NativeLibKind::RawDylib,
k => {
struct_span_err!(sess, item.span(), E0458, "unknown kind: `{}`", k)
.span_label(item.span(), "unknown kind")
.span_label(m.span, "")
.emit();
NativeLibKind::Unspecified
}
};
} else if item.has_name(sym::name) {
lib.name = item.value_str();
} else if item.has_name(sym::cfg) {
let cfg = match item.meta_item_list() {
Some(list) => list,
None => continue, // skip like historical compilers
};
if cfg.is_empty() {
sess.span_err(item.span(), "`cfg()` must have an argument");
} else if let cfg @ Some(..) = cfg[0].meta_item() {
lib.cfg = cfg.cloned();
} else {
sess.span_err(cfg[0].span(), "invalid argument for `cfg(..)`");
}
} else if item.has_name(sym::wasm_import_module) {
match item.value_str() {
Some(s) => lib.wasm_import_module = Some(s),
None => {
let msg = "must be of the form `#[link(wasm_import_module = \"...\")]`";
sess.span_err(item.span(), msg);
}
}
} else {
// currently, like past compilers, ignore unknown
// directives here.
}
}
// Do this outside the above loop so we don't depend on modifiers coming
// after kinds
if let Some(item) = items.iter().find(|item| item.has_name(sym::modifiers)) {
if let Some(modifiers) = item.value_str() {
let span = item.name_value_literal_span().unwrap();
for modifier in modifiers.as_str().split(',') {
let (modifier, value) = match modifier.strip_prefix(&['+', '-'][..]) {
Some(m) => (m, modifier.starts_with('+')),
None => {
sess.span_err(
span,
"invalid linking modifier syntax, expected '+' or '-' prefix \
before one of: bundle, verbatim, whole-archive, as-needed",
);
continue;
}
};
match (modifier, &mut lib.kind) {
("bundle", NativeLibKind::Static { bundle, .. }) => {
*bundle = Some(value);
}
("bundle", _) => sess.span_err(
span,
"bundle linking modifier is only compatible with \
`static` linking kind",
),
("verbatim", _) => lib.verbatim = Some(value),
("whole-archive", NativeLibKind::Static { whole_archive, .. }) => {
*whole_archive = Some(value);
}
("whole-archive", _) => sess.span_err(
span,
"whole-archive linking modifier is only compatible with \
`static` linking kind",
),
("as-needed", NativeLibKind::Dylib { as_needed })
| ("as-needed", NativeLibKind::Framework { as_needed }) => {
*as_needed = Some(value);
}
("as-needed", _) => sess.span_err(
span,
"as-needed linking modifier is only compatible with \
`dylib` and `framework` linking kinds",
),
_ => sess.span_err(
span,
&format!(
"unrecognized linking modifier `{}`, expected one \
of: bundle, verbatim, whole-archive, as-needed",
modifier
),
),
}
}
} else {
let msg = "must be of the form `#[link(modifiers = \"...\")]`";
sess.span_err(item.span(), msg);
}
}
// In general we require #[link(name = "...")] but we allow
// #[link(wasm_import_module = "...")] without the `name`.
let requires_name = kind_specified || lib.wasm_import_module.is_none();
if lib.name.is_none() && requires_name {
struct_span_err!(
sess,
m.span,
E0459,
"`#[link(...)]` specified without \
`name = \"foo\"`"
)
.span_label(m.span, "missing `name` argument")
.emit();
}
if lib.kind == NativeLibKind::RawDylib {
lib.dll_imports.extend(
foreign_mod_items
.iter()
.map(|child_item| self.build_dll_import(abi, child_item)),
);
}
self.register_native_lib(Some(m.span), lib);
}
}
fn visit_trait_item(&mut self, _it: &'tcx hir::TraitItem<'tcx>) {}
fn visit_impl_item(&mut self, _it: &'tcx hir::ImplItem<'tcx>) {}
fn visit_foreign_item(&mut self, _it: &'tcx hir::ForeignItem<'tcx>) {}
}
impl Collector<'tcx> {
fn register_native_lib(&mut self, span: Option<Span>, lib: NativeLib) {
if lib.name.as_ref().map_or(false, |&s| s == kw::Empty) {
match span {
Some(span) => {
struct_span_err!(
self.tcx.sess,
span,
E0454,
"`#[link(name = \"\")]` given with empty name"
)
.span_label(span, "empty name given")
.emit();
}
None => {
self.tcx.sess.err("empty library name given via `-l`");
}
}
return;
}
let is_osx = self.tcx.sess.target.is_like_osx;
if matches!(lib.kind, NativeLibKind::Framework { .. }) && !is_osx {
let msg = "native frameworks are only available on macOS targets";
match span {
Some(span) => struct_span_err!(self.tcx.sess, span, E0455, "{}", msg).emit(),
None => self.tcx.sess.err(msg),
}
}
if lib.cfg.is_some() && !self.tcx.features().link_cfg {
feature_err(
&self.tcx.sess.parse_sess,
sym::link_cfg,
span.unwrap(),
"kind=\"link_cfg\" is unstable",
)
.emit();
}
// this just unwraps lib.name; we already established that it isn't empty above.
if let (NativeLibKind::RawDylib, Some(lib_name)) = (lib.kind, lib.name) {
let span = match span {
Some(s) => s,
None => {
bug!("raw-dylib libraries are not supported on the command line");
}
};
if !self.tcx.sess.target.options.is_like_windows {
self.tcx.sess.span_fatal(
span,
"`#[link(...)]` with `kind = \"raw-dylib\"` only supported on Windows",
);
} else if !self.tcx.sess.target.options.is_like_msvc {
self.tcx.sess.span_warn(
span,
"`#[link(...)]` with `kind = \"raw-dylib\"` not supported on windows-gnu",
);
}
if lib_name.as_str().contains('\0') {
self.tcx.sess.span_err(span, "library name may not contain NUL characters");
}
if !self.tcx.features().raw_dylib {
feature_err(
&self.tcx.sess.parse_sess,
sym::raw_dylib,
span,
"kind=\"raw-dylib\" is unstable",
)
.emit();
}
}
self.libs.push(lib);
}
// Process libs passed on the command line
fn process_command_line(&mut self) {
// First, check for errors
let mut renames = FxHashSet::default();
for lib in &self.tcx.sess.opts.libs {
if let Some(ref new_name) = lib.new_name {
let any_duplicate = self
.libs
.iter()
.filter_map(|lib| lib.name.as_ref())
.any(|n| n.as_str() == lib.name);
if new_name.is_empty() {
self.tcx.sess.err(&format!(
"an empty renaming target was specified for library `{}`",
lib.name
));
} else if !any_duplicate {
self.tcx.sess.err(&format!(
"renaming of the library `{}` was specified, \
however this crate contains no `#[link(...)]` \
attributes referencing this library",
lib.name
));
} else if !renames.insert(&lib.name) {
self.tcx.sess.err(&format!(
"multiple renamings were \
specified for library `{}`",
lib.name
));
}
}
}
// Update kind and, optionally, the name of all native libraries
// (there may be more than one) with the specified name. If any
// library is mentioned more than once, keep the latest mention
// of it, so that any possible dependent libraries appear before
// it. (This ensures that the linker is able to see symbols from
// all possible dependent libraries before linking in the library
// in question.)
for passed_lib in &self.tcx.sess.opts.libs {
// If we've already added any native libraries with the same
// name, they will be pulled out into `existing`, so that we
// can move them to the end of the list below.
let mut existing = self
.libs
.drain_filter(|lib| {
if let Some(lib_name) = lib.name {
if lib_name.as_str() == passed_lib.name {
if passed_lib.kind != NativeLibKind::Unspecified {
lib.kind = passed_lib.kind;
}
if let Some(new_name) = &passed_lib.new_name {
lib.name = Some(Symbol::intern(new_name));
}
lib.verbatim = passed_lib.verbatim;
return true;
}
}
false
})
.collect::<Vec<_>>();
if existing.is_empty() {
// Add if not found
let new_name: Option<&str> = passed_lib.new_name.as_deref();
let lib = NativeLib {
name: Some(Symbol::intern(new_name.unwrap_or(&passed_lib.name))),
kind: passed_lib.kind,
cfg: None,
foreign_module: None,
wasm_import_module: None,
verbatim: passed_lib.verbatim,
dll_imports: Vec::new(),
};
self.register_native_lib(None, lib);
} else {
// Move all existing libraries with the same name to the
// end of the command line.
self.libs.append(&mut existing);
}
}
}
fn i686_arg_list_size(&self, item: &hir::ForeignItemRef) -> usize {
let argument_types: &List<Ty<'_>> = self.tcx.erase_late_bound_regions(
self.tcx
.type_of(item.id.def_id)
.fn_sig(self.tcx)
.inputs()
.map_bound(|slice| self.tcx.mk_type_list(slice.iter())),
);
argument_types
.iter()
.map(|ty| {
let layout = self
.tcx
.layout_of(ParamEnvAnd { param_env: ParamEnv::empty(), value: ty })
.expect("layout")
.layout;
// In both stdcall and fastcall, we always round up the argument size to the
// nearest multiple of 4 bytes.
(layout.size.bytes_usize() + 3) & !3
})
.sum()
}
fn build_dll_import(&self, abi: Abi, item: &hir::ForeignItemRef) -> DllImport {
let calling_convention = if self.tcx.sess.target.arch == "x86" {
match abi {
Abi::C { .. } | Abi::Cdecl => DllCallingConvention::C,
Abi::Stdcall { .. } | Abi::System { .. } => {
DllCallingConvention::Stdcall(self.i686_arg_list_size(item))
}
Abi::Fastcall => DllCallingConvention::Fastcall(self.i686_arg_list_size(item)),
// Vectorcall is intentionally not supported at this time.
_ => {
self.tcx.sess.span_fatal(
item.span,
r#"ABI not supported by `#[link(kind = "raw-dylib")]` on i686"#,
);
}
}
} else {
match abi {
Abi::C { .. } | Abi::Win64 | Abi::System { .. } => DllCallingConvention::C,
_ => {
self.tcx.sess.span_fatal(
item.span,
r#"ABI not supported by `#[link(kind = "raw-dylib")]` on this architecture"#,
);
}
}
};
DllImport {
name: item.ident.name,
ordinal: self.tcx.codegen_fn_attrs(item.id.def_id).link_ordinal,
calling_convention,
span: item.span,
}
}
}