Merge remote-tracking branch 'origin/master' into no_std

lib/wasm/src/environ/dummy.rs

@@ -1,16 +1,16 @@
 //! "Dummy" environment for testing wasm translation.
 
-use environ::{FuncEnvironment, GlobalValue, ModuleEnvironment};
-use translation_utils::{Global, Memory, Table, GlobalIndex, TableIndex, SignatureIndex,
-                        FunctionIndex, MemoryIndex};
-use func_translator::FuncTranslator;
-use cretonne::ir::{self, InstBuilder};
-use cretonne::ir::types::*;
 use cretonne::cursor::FuncCursor;
+use cretonne::ir::types::*;
+use cretonne::ir::{self, InstBuilder};
 use cretonne::settings;
-use wasmparser;
-use std::vec::Vec;
+use environ::{FuncEnvironment, GlobalValue, ModuleEnvironment};
+use func_translator::FuncTranslator;
 use std::string::String;
+use std::vec::Vec;
+use translation_utils::{FunctionIndex, Global, GlobalIndex, Memory, MemoryIndex, SignatureIndex,
+                        Table, TableIndex};
+use wasmparser;
 
 /// Compute a `ir::ExternalName` for a given wasm function index.
 fn get_func_name(func_index: FunctionIndex) -> ir::ExternalName {
@@ -120,7 +120,7 @@ impl DummyEnvironment {
     }
 }
 
-/// The FuncEnvironment implementation for use by the `DummyEnvironment`.
+/// The `FuncEnvironment` implementation for use by the `DummyEnvironment`.
 pub struct DummyFuncEnvironment<'dummy_environment> {
     pub mod_info: &'dummy_environment DummyModuleInfo,
 }
@@ -208,7 +208,10 @@ impl<'dummy_environment> FuncEnvironment for DummyFuncEnvironment<'dummy_environ
             let ext = pos.ins().uextend(I64, callee);
             pos.ins().imul_imm(ext, 4)
         };
-        let func_ptr = pos.ins().load(ptr, ir::MemFlags::new(), callee_offset, 0);
+        let mut mflags = ir::MemFlags::new();
+        mflags.set_notrap();
+        mflags.set_aligned();
+        let func_ptr = pos.ins().load(ptr, mflags, callee_offset, 0);
 
         // Build a value list for the indirect call instruction containing the callee, call_args,
         // and the vmctx parameter.

lib/wasm/src/environ/mod.rs

@@ -1,7 +1,7 @@
 //! Support for configurable wasm translation.
 
-mod spec;
 mod dummy;
+mod spec;
 
-pub use environ::spec::{ModuleEnvironment, FuncEnvironment, GlobalValue};
 pub use environ::dummy::DummyEnvironment;
+pub use environ::spec::{FuncEnvironment, GlobalValue, ModuleEnvironment};

lib/wasm/src/environ/spec.rs

@@ -1,12 +1,12 @@
 //! All the runtime support necessary for the wasm to cretonne translation is formalized by the
 //! traits `FunctionEnvironment` and `ModuleEnvironment`.
-use cretonne::ir::{self, InstBuilder};
 use cretonne::cursor::FuncCursor;
+use cretonne::ir::{self, InstBuilder};
 use cretonne::settings::Flags;
-use translation_utils::{SignatureIndex, FunctionIndex, TableIndex, GlobalIndex, MemoryIndex,
-                        Global, Table, Memory};
-use std::vec::Vec;
 use std::string::String;
+use std::vec::Vec;
+use translation_utils::{FunctionIndex, Global, GlobalIndex, Memory, MemoryIndex, SignatureIndex,
+                        Table, TableIndex};
 
 /// The value of a WebAssembly global variable.
 #[derive(Clone, Copy)]
@@ -26,7 +26,7 @@ pub enum GlobalValue {
 /// Environment affecting the translation of a single WebAssembly function.
 ///
 /// A `FuncEnvironment` trait object is required to translate a WebAssembly function to Cretonne
-/// IL. The function environment provides information about the WebAssembly module as well as the
+/// IR. The function environment provides information about the WebAssembly module as well as the
 /// runtime environment.
 pub trait FuncEnvironment {
     /// Get the flags for the current compilation.
@@ -146,6 +146,14 @@ pub trait FuncEnvironment {
         index: MemoryIndex,
         heap: ir::Heap,
     ) -> ir::Value;
+
+    /// Emit code at the beginning of every wasm loop.
+    ///
+    /// This can be used to insert explicit interrupt or safepoint checking at
+    /// the beginnings of loops.
+    fn translate_loop_header(&mut self, _pos: FuncCursor) {
+        // By default, don't emit anything.
+    }
 }
 
 /// An object satisfying the `ModuleEnvironment` trait can be passed as argument to the