Rollup merge of rust-lang#81618 - bjorn3:sync_cg_clif-2021-02-01, r=bjorn3

Sync rustc_codegen_cranelift

The highlight of this sync are abi compatibility with cg_llvm allowing mixing of cg_clif and cg_llvm compiled crates and switching to the x64 cranelift backend based on the new backend framework.

r? ``@ghost``

``@rustbot`` label +A-codegen +A-cranelift +T-compiler

Author: jonas-schievink

.github/workflows/main.yml

@@ -12,6 +12,9 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, macos-latest]
+        env:
+          - BACKEND: ""
+          - BACKEND: --oldbe
 
     steps:
     - uses: actions/checkout@v2
@@ -51,7 +54,7 @@ jobs:
         export COMPILE_RUNS=2
         export RUN_RUNS=2
 
-        ./test.sh
+        ./test.sh $BACKEND
 
     - name: Package prebuilt cg_clif
       run: tar cvfJ cg_clif.tar.xz build

.gitignore

@@ -8,6 +8,7 @@ perf.data.old
 *.string*
 /build
 /build_sysroot/sysroot_src
+/build_sysroot/compiler-builtins
 /rust
 /rand
 /regex

.vscode/settings.json

@@ -1,7 +1,7 @@
 {
     // source for rustc_* is not included in the rust-src component; disable the errors about this
     "rust-analyzer.diagnostics.disabled": ["unresolved-extern-crate"],
-    "rust-analyzer.assist.importMergeBehaviour": "last",
+    "rust-analyzer.assist.importMergeBehavior": "last",
     "rust-analyzer.cargo.loadOutDirsFromCheck": true,
     "rust-analyzer.linkedProjects": [
         "./Cargo.toml",

Cargo.lock

@@ -9,7 +9,7 @@ crate-type = ["dylib"]
 
 [dependencies]
 # These have to be in sync with each other
-cranelift-codegen = { git = "https://github.com/bytecodealliance/wasmtime/", branch = "main", features = ["unwind"] }
+cranelift-codegen = { git = "https://github.com/bytecodealliance/wasmtime/", branch = "main", features = ["unwind", "x86", "x64"] }
 cranelift-frontend = { git = "https://github.com/bytecodealliance/wasmtime/", branch = "main" }
 cranelift-module = { git = "https://github.com/bytecodealliance/wasmtime/", branch = "main" }
 cranelift-jit = { git = "https://github.com/bytecodealliance/wasmtime/", branch = "main", optional = true }
@@ -21,6 +21,7 @@ object = { version = "0.22.0", default-features = false, features = ["std", "rea
 ar = { git = "https://github.com/bjorn3/rust-ar.git", branch = "do_not_remove_cg_clif_ranlib" }
 indexmap = "1.0.2"
 libloading = { version = "0.6.0", optional = true }
+smallvec = "1.6.1"
 
 # Uncomment to use local checkout of cranelift
 #[patch."https://github.com/bytecodealliance/wasmtime/"]
@@ -37,6 +38,7 @@ libloading = { version = "0.6.0", optional = true }
 default = ["jit", "inline_asm"]
 jit = ["cranelift-jit", "libloading"]
 inline_asm = []
+oldbe = []
 
 [profile.dev]
 # By compiling dependencies with optimizations, performing tests gets much faster.

Cargo.toml

@@ -1,6 +1,4 @@
-# WIP Cranelift codegen backend for rust
-
-> ⚠⚠⚠ Certain kinds of FFI don't work yet. ⚠⚠⚠
+# Cranelift codegen backend for rust
 
 The goal of this project is to create an alternative codegen backend for the rust compiler based on [Cranelift](https://github.com/bytecodealliance/wasmtime/blob/main/cranelift).
 This has the potential to improve compilation times in debug mode.
@@ -103,8 +101,7 @@ function jit_calc() {
 
 ## Not yet supported
 
-* Good non-rust abi support ([several problems](https://github.com/bjorn3/rustc_codegen_cranelift/issues/10))
-* Inline assembly ([no cranelift support](https://github.com/bytecodealliance/wasmtime/issues/1041)
+* Inline assembly ([no cranelift support](https://github.com/bytecodealliance/wasmtime/issues/1041))
     * On Linux there is support for invoking an external assembler for `global_asm!` and `asm!`.
       `llvm_asm!` will remain unimplemented forever. `asm!` doesn't yet support reg classes. You
       have to specify specific registers instead.