Migrate to 2021 edition (#187)

This migrates mmtk-openjdk to Rust 2021 edition, the same as mmtk-core.  It should not change the behaviour of mmtk-openjdk in any way.

Author: wks

mmtk/Cargo.lock

@@ -4,6 +4,7 @@ version = "0.15.0"
 authors = [" <>"]
 rust-version = "1.57.0"
 build = "build.rs"
+edition = "2021"
 
 [lib]
 name = "mmtk_openjdk"

mmtk/Cargo.toml

@@ -1,4 +1,4 @@
-use super::UPCALLS;
+use crate::UPCALLS;
 use mmtk::util::constants::*;
 use mmtk::util::conversions;
 use mmtk::util::ObjectReference;

mmtk/src/abi.rs

@@ -1,6 +1,6 @@
-use super::UPCALLS;
 use crate::OpenJDK;
 use crate::SINGLETON;
+use crate::UPCALLS;
 use mmtk::util::opaque_pointer::*;
 use mmtk::vm::ActivePlan;
 use mmtk::Mutator;

mmtk/src/active_plan.rs

@@ -1,10 +1,10 @@
 use std::sync::atomic::Ordering;
 
-use super::{OpenJDK, OpenJDKEdge, UPCALLS};
+use crate::scanning::to_edges_closure;
+use crate::{OpenJDK, OpenJDKEdge, UPCALLS};
 use mmtk::scheduler::*;
 use mmtk::vm::RootsWorkFactory;
 use mmtk::MMTK;
-use scanning::to_edges_closure;
 
 macro_rules! scan_roots_work {
     ($struct_name: ident, $func_name: ident) => {

mmtk/src/gc_work.rs

@@ -1,8 +1,5 @@
-extern crate libc;
-extern crate mmtk;
 #[macro_use]
 extern crate lazy_static;
-extern crate once_cell;
 
 use std::collections::HashMap;
 use std::ops::Range;
@@ -15,9 +12,7 @@ use mmtk::util::alloc::AllocationError;
 use mmtk::util::opaque_pointer::*;
 use mmtk::util::{Address, ObjectReference};
 use mmtk::vm::VMBinding;
-use mmtk::MMTKBuilder;
-use mmtk::Mutator;
-use mmtk::MMTK;
+use mmtk::{MMTKBuilder, Mutator, MMTK};
 
 mod abi;
 pub mod active_plan;
@@ -106,15 +101,15 @@ pub static mut UPCALLS: *const OpenJDK_Upcalls = null_mut();
 
 #[no_mangle]
 pub static GLOBAL_SIDE_METADATA_BASE_ADDRESS: uintptr_t =
-    crate::mmtk::util::metadata::side_metadata::GLOBAL_SIDE_METADATA_BASE_ADDRESS.as_usize();
+    mmtk::util::metadata::side_metadata::GLOBAL_SIDE_METADATA_BASE_ADDRESS.as_usize();
 
 #[no_mangle]
 pub static GLOBAL_SIDE_METADATA_VM_BASE_ADDRESS: uintptr_t =
-    crate::mmtk::util::metadata::side_metadata::GLOBAL_SIDE_METADATA_VM_BASE_ADDRESS.as_usize();
+    mmtk::util::metadata::side_metadata::GLOBAL_SIDE_METADATA_VM_BASE_ADDRESS.as_usize();
 
 #[no_mangle]
 pub static GLOBAL_ALLOC_BIT_ADDRESS: uintptr_t =
-    crate::mmtk::util::metadata::side_metadata::ALLOC_SIDE_METADATA_ADDR.as_usize();
+    mmtk::util::metadata::side_metadata::ALLOC_SIDE_METADATA_ADDR.as_usize();
 
 #[derive(Default)]
 pub struct OpenJDK;

mmtk/src/lib.rs

@@ -1,5 +1,5 @@
-use super::UPCALLS;
 use crate::abi::Oop;
+use crate::UPCALLS;
 use crate::{vm_metadata, OpenJDK};
 use mmtk::util::alloc::fill_alignment_gap;
 use mmtk::util::copy::*;