Add custom driver

[rust.git] / src / metadata.rs

diff --git a/src/metadata.rs b/src/metadata.rs
index 8d17922725aa7c794fde5ea6a715bdf0ed5e0f11..93cff5711d937ec4234ac44efb01bce1847ba33a 100644 (file)
--- a/src/metadata.rs
+++ b/src/metadata.rs
@@ -1,15 +1,20 @@
+//! Reading and writing of the rustc metadata for rlibs and dylibs
+
+use std::convert::TryFrom;
 use std::fs::File;
 use std::path::Path;
 
-use rustc::middle::cstore::{EncodedMetadata, MetadataLoader};
-use rustc::session::config;
-use rustc::ty::TyCtxt;
 use rustc_codegen_ssa::METADATA_FILENAME;
 use rustc_data_structures::owning_ref::{self, OwningRef};
 use rustc_data_structures::rustc_erase_owner;
+use rustc_middle::middle::cstore::{EncodedMetadata, MetadataLoader};
+use rustc_middle::ty::TyCtxt;
+use rustc_session::config;
 use rustc_target::spec::Target;
 
-pub struct CraneliftMetadataLoader;
+use crate::backend::WriteMetadata;
+
+pub(crate) struct CraneliftMetadataLoader;
 
 impl MetadataLoader for CraneliftMetadataLoader {
     fn get_rlib_metadata(
@@ -22,7 +27,10 @@ fn get_rlib_metadata(
         while let Some(entry_result) = archive.next_entry() {
             let mut entry = entry_result.map_err(|e| format!("{:?}", e))?;
             if entry.header().identifier() == METADATA_FILENAME.as_bytes() {
-                let mut buf = Vec::new();
+                let mut buf = Vec::with_capacity(
+                    usize::try_from(entry.header().size())
+                        .expect("Rlib metadata file too big to load into memory."),
+                );
                 ::std::io::copy(&mut entry, &mut buf).map_err(|e| format!("{:?}", e))?;
                 let buf: OwningRef<Vec<u8>, [u8]> = OwningRef::new(buf).into();
                 return Ok(rustc_erase_owner!(buf.map_owner_box()));
@@ -38,22 +46,26 @@ fn get_dylib_metadata(
         _target: &Target,
         path: &Path,
     ) -> Result<owning_ref::ErasedBoxRef<[u8]>, String> {
-        use object::Object;
+        use object::{Object, ObjectSection};
         let file = std::fs::read(path).map_err(|e| format!("read:{:?}", e))?;
         let file = object::File::parse(&file).map_err(|e| format!("parse: {:?}", e))?;
         let buf = file
-            .section_data_by_name(".rustc")
+            .section_by_name(".rustc")
             .ok_or("no .rustc section")?
-            .into_owned();
+            .data()
+            .map_err(|e| format!("failed to read .rustc section: {:?}", e))?
+            .to_owned();
         let buf: OwningRef<Vec<u8>, [u8]> = OwningRef::new(buf).into();
         Ok(rustc_erase_owner!(buf.map_owner_box()))
     }
 }
 
 // Adapted from https://github.com/rust-lang/rust/blob/da573206f87b5510de4b0ee1a9c044127e409bd3/src/librustc_codegen_llvm/base.rs#L47-L112
-pub fn write_metadata(tcx: TyCtxt<'_>, artifact: &mut faerie::Artifact) -> EncodedMetadata {
-    use flate2::write::DeflateEncoder;
-    use flate2::Compression;
+pub(crate) fn write_metadata<P: WriteMetadata>(
+    tcx: TyCtxt<'_>,
+    product: &mut P,
+) -> EncodedMetadata {
+    use snap::write::FrameEncoder;
     use std::io::Write;
 
     #[derive(PartialEq, Eq, PartialOrd, Ord)]
@@ -65,8 +77,7 @@ enum MetadataKind {
 
     let kind = tcx
         .sess
-        .crate_types
-        .borrow()
+        .crate_types()
         .iter()
         .map(|ty| match *ty {
             config::CrateType::Executable
@@ -91,28 +102,15 @@ enum MetadataKind {
 
     assert!(kind == MetadataKind::Compressed);
     let mut compressed = tcx.metadata_encoding_version();
-    DeflateEncoder::new(&mut compressed, Compression::fast())
+    FrameEncoder::new(&mut compressed)
         .write_all(&metadata.raw_data)
         .unwrap();
 
-    artifact
-        .declare(".rustc", faerie::Decl::section(faerie::SectionKind::Data))
-        .unwrap();
-    artifact
-        .define_with_symbols(".rustc", compressed, {
-            let mut map = std::collections::BTreeMap::new();
-            // FIXME implement faerie elf backend section custom symbols
-            // For MachO this is necessary to prevent the linker from throwing away the .rustc section,
-            // but for ELF it isn't.
-            if tcx.sess.target.target.options.is_like_osx {
-                map.insert(
-                    rustc::middle::exported_symbols::metadata_symbol_name(tcx),
-                    0,
-                );
-            }
-            map
-        })
-        .unwrap();
+    product.add_rustc_section(
+        rustc_middle::middle::exported_symbols::metadata_symbol_name(tcx),
+        compressed,
+        tcx.sess.target.target.options.is_like_osx,
+    );
 
     metadata
 }