Fix it

Author: bjorn3

Cargo.lock

@@ -41,8 +41,8 @@ object = "0.12.0"
 cranelift-simplejit = { git = "https://github.com/CraneStation/cranelift.git" }
 
 [patch.crates-io]
-faerie = { path = "../faerie" }
-object = { path = "../object" }
+faerie = { git = "https://github.com/m4b/faerie.git" }
+object = { git = "https://github.com/gimli-rs/object.git" }
 
 [profile.dev.overrides."*"]
 opt-level = 3

Cargo.toml

@@ -93,7 +93,12 @@ pub fn write_metadata<'a, 'gcx>(
     artifact.declare(".rustc", faerie::Decl::section(faerie::SectionKind::Data)).unwrap();
     artifact.define_with_symbols(".rustc", compressed, {
         let mut map = std::collections::BTreeMap::new();
-        map.insert(rustc::middle::exported_symbols::metadata_symbol_name(tcx), 0);
+        // 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();
 

src/metadata.rs

@@ -7,8 +7,6 @@ mkdir -p target/out/clif
 echo "[BUILD] mini_core"
 $RUSTC example/mini_core.rs --crate-name mini_core --crate-type dylib -Csave-temps
 
-objdump -section-headers target/out/libmini_core.dylib
-
 echo "[BUILD] example"
 $RUSTC example/example.rs --crate-type lib