[WIP] Tls support

Author: bjorn3

Cargo.lock

@@ -30,12 +30,12 @@ default-features = false
 features = ["write"] # We don't need read support
 
 # Uncomment to use local checkout of cranelift
-#[patch."https://github.com/bytecodealliance/cranelift/"]
-#cranelift-codegen = { path = "../cranelift/cranelift-codegen" }
-#cranelift-frontend = { path = "../cranelift/cranelift-frontend" }
-#cranelift-module = { path = "../cranelift/cranelift-module" }
-#cranelift-simplejit = { path = "../cranelift/cranelift-simplejit" }
-#cranelift-object = { path = "../cranelift/cranelift-object" }
+[patch."https://github.com/bytecodealliance/cranelift/"]
+cranelift-codegen = { path = "../cranelift/cranelift-codegen", default-features = false, features = ["std"] }
+cranelift-frontend = { path = "../cranelift/cranelift-frontend", default-features = false, features = ["std"] }
+cranelift-module = { path = "../cranelift/cranelift-module" }
+cranelift-simplejit = { path = "../cranelift/cranelift-simplejit" }
+cranelift-object = { path = "../cranelift/cranelift-object" }
 
 #[patch.crates-io]
 #gimli = { path = "../" }

Cargo.toml

@@ -1,6 +1,7 @@
 #![feature(
     no_core, lang_items, intrinsics, unboxed_closures, type_ascription, extern_types,
-    untagged_unions, decl_macro, rustc_attrs, transparent_unions, optin_builtin_traits
+    untagged_unions, decl_macro, rustc_attrs, transparent_unions, optin_builtin_traits,
+    thread_local,
 )]
 #![no_core]
 #![allow(dead_code)]
@@ -551,3 +552,11 @@ struct PanicLocation {
     line: u32,
     column: u32,
 }
+
+#[no_mangle]
+pub fn get_tls() -> u8 {
+    #[thread_local]
+    static A: u8 = 42;
+
+    A
+}

crate_patches/regex.patch

@@ -1,8 +1,11 @@
 // Adapted from https://github.com/sunfishcode/mir2cranelift/blob/master/rust-examples/nocore-hello-world.rs
 
-#![feature(no_core, unboxed_closures, start, lang_items, box_syntax, slice_patterns, never_type, linkage, extern_types)]
+#![feature(
+    no_core, unboxed_closures, start, lang_items, box_syntax, slice_patterns, never_type, linkage,
+    extern_types, thread_local
+)]
 #![no_core]
-#![allow(dead_code)]
+#![allow(dead_code, non_camel_case_types)]
 
 extern crate mini_core;
 
@@ -276,6 +279,74 @@ fn main() {
     extern_nullptr as *const ();
     let slice_ptr = &[] as *const [u8];
     slice_ptr as *const u8;
+
+    test_tls();
+}
+
+#[repr(C)]
+enum c_void {
+    _1,
+    _2,
+}
+
+type c_int = i32;
+type c_ulong = u64;
+
+type pthread_t = c_ulong;
+
+#[repr(C)]
+struct pthread_attr_t {
+    __size: [u64; 7],
+}
+
+#[link(name = "pthread")]
+extern "C" {
+    fn pthread_attr_init(attr: *mut pthread_attr_t) -> c_int;
+
+    fn pthread_create(
+        native: *mut pthread_t,
+        attr: *const pthread_attr_t,
+        f: extern "C" fn(_: *mut c_void) -> *mut c_void,
+        value: *mut c_void
+    ) -> c_int;
+
+    fn pthread_join(
+        native: pthread_t,
+        value: *mut *mut c_void
+    ) -> c_int;
+}
+
+#[thread_local]
+static mut TLS: u8 = 42;
+
+extern "C" fn mutate_tls(_: *mut c_void) -> *mut c_void {
+    unsafe { TLS = 0; }
+    0 as *mut c_void
+}
+
+fn test_tls() {
+    unsafe {
+        let mut attr: pthread_attr_t = intrinsics::init();
+        let mut thread: pthread_t = 0;
+
+        assert_eq!(TLS, 42);
+
+        if pthread_attr_init(&mut attr) != 0 {
+            assert!(false);
+        }
+
+        if pthread_create(&mut thread, &attr, mutate_tls, 0 as *mut c_void) != 0 {
+            assert!(false);
+        }
+
+        let mut res = 0 as *mut c_void;
+        pthread_join(thread, &mut res);
+
+        // TLS of main thread must not have been changed by the other thread.
+        assert_eq!(TLS, 42);
+
+        puts("TLS works!\n\0" as *const str as *const u8);
+    }
 }
 
 // Copied ui/issues/issue-61696.rs

example/mini_core.rs

@@ -12,6 +12,10 @@ fn main() {
     let stderr = ::std::io::stderr();
     let mut stderr = stderr.lock();
 
+    std::thread::spawn(move || {
+        println!("Hello from another thread!");
+    });
+
     writeln!(stderr, "some {} text", "<unknown>").unwrap();
 
     let _ = std::process::Command::new("true").env("c", "d").spawn();

example/mini_core_hello_world.rs

@@ -95,8 +95,9 @@ index 143cf2f..a6e8faf 100644
      // unsafe: see thread::Builder::spawn_unchecked for safety requirements
 -    pub unsafe fn new(stack: usize, p: Box<dyn FnOnce()>) -> io::Result<Thread> {
 +    pub unsafe fn new(stack: usize, p: Box<dyn FnBox()>) -> io::Result<Thread> {
-         panic!("Warning: Threads are not yet fully supported, because cranelift doesn't support atomics.");
- 
+-        panic!("Warning: Threads are not yet fully supported, because cranelift doesn't support atomics.");
++        println!("Spawned thread");
+
          let p = box p;
          let mut native: libc::pthread_t = mem::zeroed();
 diff --git a/src/libstd/sys_common/at_exit_imp.rs b/src/libstd/sys_common/at_exit_imp.rs

example/std_example.rs

@@ -9,7 +9,6 @@ git clone https://github.com/rust-lang/regex.git || echo "rust-lang/regex has al
 pushd regex
 git checkout -- .
 git checkout 341f207c1071f7290e3f228c710817c280c8dca1
-git apply ../crate_patches/regex.patch
 popd
 
 git clone https://github.com/ebobby/simple-raytracer || echo "ebobby/simple-raytracer has already been cloned"

patches/0018-Add-FnBox-back.patch

@@ -22,6 +22,7 @@ pub fn init_global_lock(module: &mut Module<impl Backend>, bcx: &mut FunctionBui
         "__cg_clif_global_atomic_mutex",
         Linkage::Export,
         true,
+        false,
         Some(16),
     ).unwrap();
     module.define_data(atomic_mutex, &data_ctx).unwrap();
@@ -50,6 +51,7 @@ pub fn lock_global_lock(fx: &mut FunctionCx<'_, '_, impl Backend>) {
         "__cg_clif_global_atomic_mutex",
         Linkage::Import,
         true,
+        false,
         None,
     ).unwrap();
 
@@ -74,6 +76,7 @@ pub fn unlock_global_lock(fx: &mut FunctionCx<'_, '_, impl Backend>) {
         "__cg_clif_global_atomic_mutex",
         Linkage::Import,
         true,
+        false,
         None,
     ).unwrap();
 

prepare.sh

@@ -247,6 +247,7 @@ fn data_id_for_alloc_id<B: Backend>(
             &format!("__alloc_{}", alloc_id.0),
             Linkage::Local,
             false,
+            false,
             Some(align.bytes() as u8),
         )
         .unwrap()
@@ -273,11 +274,14 @@ fn data_id_for_static(
         .pref
         .bytes();
 
+    let attrs = tcx.codegen_fn_attrs(def_id);
+
     let data_id = module
         .declare_data(
             &*symbol_name,
             linkage,
             is_mutable,
+            attrs.flags.contains(rustc::middle::codegen_fn_attrs::CodegenFnAttrFlags::THREAD_LOCAL),
             Some(align.try_into().unwrap()),
         )
         .unwrap();