rust/src/comp/metadata/creader.rs
Brian Anderson dd8ab24da2 Add a map from external cnums to local cnums in cstore::crate_metadata
Once populated, this will allow us to load type info for types defined in
external crates referenced by other external crates.
2011-07-08 14:07:41 -07:00

264 lines
9.0 KiB
Rust

// Extracting metadata from crate files
import driver::session;
import syntax::ast;
import lib::llvm::False;
import lib::llvm::llvm;
import lib::llvm::mk_object_file;
import lib::llvm::mk_section_iter;
import front::attr;
import middle::resolve;
import syntax::walk;
import syntax::codemap::span;
import back::x86;
import util::common;
import std::ivec;
import std::str;
import std::vec;
import std::ebml;
import std::fs;
import std::io;
import std::option;
import std::option::none;
import std::option::some;
import std::map::hashmap;
import std::map::new_int_hash;
import syntax::print::pprust;
import common::*;
export read_crates;
export list_file_metadata;
// Traverses an AST, reading all the information about use'd crates and native
// libraries necessary for later resolving, typechecking, linking, etc.
fn read_crates(session::session sess,
&ast::crate crate) {
auto e =
@rec(sess=sess,
crate_cache=@std::map::new_str_hash[int](),
library_search_paths=sess.get_opts().library_search_paths,
mutable next_crate_num=1);
auto v =
rec(visit_view_item_pre=bind visit_view_item(e, _),
visit_item_pre=bind visit_item(e, _)
with walk::default_visitor());
walk::walk_crate(v, crate);
}
type env =
@rec(session::session sess,
@hashmap[str, int] crate_cache,
vec[str] library_search_paths,
mutable ast::crate_num next_crate_num);
fn visit_view_item(env e, &@ast::view_item i) {
alt (i.node) {
case (ast::view_item_use(?ident, ?meta_items, ?id)) {
auto cnum = resolve_crate(e, ident, meta_items, i.span);
cstore::add_use_stmt_cnum(e.sess.get_cstore(), id, cnum);
}
case (_) { }
}
}
fn visit_item(env e, &@ast::item i) {
alt (i.node) {
case (ast::item_native_mod(?m)) {
if (m.abi != ast::native_abi_rust &&
m.abi != ast::native_abi_cdecl) {
ret;
}
auto cstore = e.sess.get_cstore();
if (!cstore::add_used_library(cstore, m.native_name)) {
ret;
}
for (ast::attribute a in
attr::find_attrs_by_name(i.attrs, "link_args")) {
alt (attr::get_meta_item_value_str(attr::attr_meta(a))) {
case (some(?linkarg)) {
cstore::add_used_link_args(cstore, linkarg);
}
case (none) { /* fallthrough */ }
}
}
}
case (_) {
}
}
}
// A diagnostic function for dumping crate metadata to an output stream
fn list_file_metadata(str path, io::writer out) {
alt (get_metadata_section(path)) {
case (option::some(?bytes)) {
decoder::list_crate_metadata(bytes, out);
}
case (option::none) {
out.write_str("Could not find metadata in " + path + ".\n");
}
}
}
fn metadata_matches(&vec[u8] crate_data,
&(@ast::meta_item)[] metas) -> bool {
auto attrs = decoder::get_crate_attributes(crate_data);
auto linkage_metas = attr::find_linkage_metas(attrs);
log #fmt("matching %u metadata requirements against %u items",
ivec::len(metas), ivec::len(linkage_metas));
for (@ast::meta_item needed in metas) {
if (!attr::contains(linkage_metas, needed)) {
log #fmt("missing %s", pprust::meta_item_to_str(*needed));
ret false;
}
}
ret true;
}
fn default_native_lib_naming(session::session sess, bool static) ->
rec(str prefix, str suffix) {
if (static) {
ret rec(prefix="lib", suffix=".rlib");
}
alt (sess.get_targ_cfg().os) {
case (session::os_win32) { ret rec(prefix="", suffix=".dll"); }
case (session::os_macos) { ret rec(prefix="lib", suffix=".dylib"); }
case (session::os_linux) { ret rec(prefix="lib", suffix=".so"); }
}
}
fn find_library_crate(&session::session sess, &ast::ident ident,
&(@ast::meta_item)[] metas,
&vec[str] library_search_paths) ->
option::t[tup(str, vec[u8])] {
attr::require_unique_names(sess, metas);
auto crate_name = {
auto name_items = attr::find_meta_items_by_name(metas, "name");
alt (ivec::last(name_items)) {
case (some(?i)) {
alt (attr::get_meta_item_value_str(i)) {
case (some(?n)) { n }
case (_) {
// FIXME: Probably want a warning here since the user
// is using the wrong type of meta item
ident
}
}
}
case (none) { ident }
}
};
auto nn = default_native_lib_naming(sess, sess.get_opts().static);
auto x = find_library_crate_aux(nn, crate_name, metas,
library_search_paths);
if (x != none || sess.get_opts().static) {
ret x;
}
auto nn2 = default_native_lib_naming(sess, true);
ret find_library_crate_aux(nn2, crate_name, metas, library_search_paths);
}
fn find_library_crate_aux(&rec(str prefix, str suffix) nn, str crate_name,
&(@ast::meta_item)[] metas,
&vec[str] library_search_paths) ->
option::t[tup(str, vec[u8])] {
let str prefix = nn.prefix + crate_name;
// FIXME: we could probably use a 'glob' function in std::fs but it will
// be much easier to write once the unsafe module knows more about FFI
// tricks. Currently the glob(3) interface is a bit more than we can
// stomach from here, and writing a C++ wrapper is more work than just
// manually filtering fs::list_dir here.
for (str library_search_path in library_search_paths) {
log #fmt("searching %s", library_search_path);
for (str path in fs::list_dir(library_search_path)) {
log #fmt("searching %s", path);
let str f = fs::basename(path);
if (!(str::starts_with(f, prefix) &&
str::ends_with(f, nn.suffix))) {
log #fmt("skipping %s, doesn't look like %s*%s", path, prefix,
nn.suffix);
cont;
}
alt (get_metadata_section(path)) {
case (option::some(?cvec)) {
if (!metadata_matches(cvec, metas)) {
log #fmt("skipping %s, metadata doesn't match", path);
cont;
}
log #fmt("found %s with matching metadata", path);
ret some(tup(path, cvec));
}
case (_) { }
}
}
}
ret none;
}
fn get_metadata_section(str filename) -> option::t[vec[u8]] {
auto b = str::buf(filename);
auto mb = llvm::LLVMRustCreateMemoryBufferWithContentsOfFile(b);
if (mb as int == 0) { ret option::none[vec[u8]]; }
auto of = mk_object_file(mb);
auto si = mk_section_iter(of.llof);
while (llvm::LLVMIsSectionIteratorAtEnd(of.llof, si.llsi) == False) {
auto name_buf = llvm::LLVMGetSectionName(si.llsi);
auto name = str::str_from_cstr(name_buf);
if (str::eq(name, x86::get_meta_sect_name())) {
auto cbuf = llvm::LLVMGetSectionContents(si.llsi);
auto csz = llvm::LLVMGetSectionSize(si.llsi);
auto cvbuf = cbuf as vec::vbuf;
ret option::some[vec[u8]](vec::vec_from_vbuf[u8](cvbuf, csz));
}
llvm::LLVMMoveToNextSection(si.llsi);
}
ret option::none[vec[u8]];
}
fn load_library_crate(&session::session sess, span span, ast::crate_num cnum,
&ast::ident ident, &(@ast::meta_item)[] metas,
&vec[str] library_search_paths) {
alt (find_library_crate(sess, ident, metas, library_search_paths)) {
case (some(?t)) {
auto cstore = sess.get_cstore();
auto cmeta = rec(name=ident,
data=t._1,
cnum_map = new_int_hash[ast::crate_num]());
cstore::set_crate_data(cstore, cnum, cmeta);
cstore::add_used_crate_file(cstore, t._0);
ret;
}
case (_) { }
}
sess.span_fatal(span, #fmt("can't find crate for '%s'", ident));
}
fn resolve_crate(env e, ast::ident ident, (@ast::meta_item)[] metas,
span span) -> ast::crate_num {
if (!e.crate_cache.contains_key(ident)) {
auto cnum = e.next_crate_num;
load_library_crate(e.sess, span, cnum, ident,
metas, e.library_search_paths);
e.crate_cache.insert(ident, e.next_crate_num);
e.next_crate_num += 1;
ret cnum;
} else {
ret e.crate_cache.get(ident);
}
}
// Local Variables:
// mode: rust
// fill-column: 78;
// indent-tabs-mode: nil
// c-basic-offset: 4
// buffer-file-coding-system: utf-8-unix
// compile-command: "make -k -C $RBUILD 2>&1 | sed -e 's/\\/x\\//x:\\//g'";
// End: