Merge pull request #33 from losfair/wasmer-lib

Allow using wasmer as a library and install signal handler only once.

src/bin/wasmer.rs

@@ -1,19 +1,5 @@
-#[macro_use]
-extern crate error_chain;
-extern crate cranelift_codegen;
-extern crate cranelift_entity;
-extern crate cranelift_native;
-extern crate cranelift_wasm;
-extern crate libc;
-extern crate memmap;
-extern crate region;
 extern crate structopt;
-extern crate wabt;
-extern crate wasmparser;
-#[macro_use]
-extern crate target_lexicon;
-extern crate nix;
-extern crate rayon;
+extern crate wasmer;
 
 use std::fs::File;
 use std::io;
@@ -23,16 +9,7 @@ use std::process::exit;
 
 use structopt::StructOpt;
 
-#[macro_use]
-mod macros;
-#[macro_use]
-mod recovery;
-pub mod apis;
-pub mod common;
-pub mod sighandler;
-#[cfg(test)]
-mod spectests;
-pub mod webassembly;
+use wasmer::*;
 
 #[derive(Debug, StructOpt)]
 #[structopt(name = "wasmer", about = "WASM execution runtime.")]

src/lib.rs

@@ -0,0 +1,27 @@
+#[macro_use]
+extern crate error_chain;
+extern crate cranelift_codegen;
+extern crate cranelift_entity;
+extern crate cranelift_native;
+extern crate cranelift_wasm;
+extern crate libc;
+extern crate memmap;
+extern crate region;
+extern crate structopt;
+extern crate wabt;
+extern crate wasmparser;
+#[macro_use]
+extern crate target_lexicon;
+pub extern crate nix; // re-exported for usage in macros
+extern crate rayon;
+
+#[macro_use]
+mod macros;
+#[macro_use]
+pub mod recovery;
+pub mod apis;
+pub mod common;
+pub mod sighandler;
+#[cfg(test)]
+mod spectests;
+pub mod webassembly;

src/recovery.rs

@@ -5,9 +5,7 @@
 //! unless you have memory unsafety elsewhere in your code.
 
 use std::cell::UnsafeCell;
-use nix::sys::signal::{Signal, SIGFPE, SIGILL, SIGSEGV, SIGBUS};
-use super::webassembly::ErrorKind;
-use super::sighandler::install_sighandler;
+use std::sync::Once;
 
 extern "C" {
     pub fn setjmp(env: *mut ::nix::libc::c_void) -> ::nix::libc::c_int;
@@ -15,6 +13,7 @@ extern "C" {
 }
 
 const SETJMP_BUFFER_LEN: usize = 27;
+pub static SIGHANDLER_INIT: Once = Once::new();
 
 thread_local! {
     pub static SETJMP_BUFFER: UnsafeCell<[::nix::libc::c_int; SETJMP_BUFFER_LEN]> = UnsafeCell::new([0; SETJMP_BUFFER_LEN]);
@@ -29,39 +28,42 @@ thread_local! {
 /// the behavior of call_protected is undefined.
 #[macro_export]
 macro_rules! call_protected {
-    ($x:expr) => {unsafe {
-        use crate::webassembly::ErrorKind;
-        use crate::recovery::{SETJMP_BUFFER, setjmp};
-        use crate::sighandler::install_sighandler;
+    ($x:expr) => {
+        unsafe {
+            use crate::recovery::{setjmp, SETJMP_BUFFER, SIGHANDLER_INIT};
+            use crate::sighandler::install_sighandler;
+            use crate::webassembly::ErrorKind;
 
-        use nix::sys::signal::{Signal, SIGFPE, SIGILL, SIGSEGV, SIGBUS};
+            use crate::nix::sys::signal::{Signal, SIGBUS, SIGFPE, SIGILL, SIGSEGV};
 
-        let jmp_buf = SETJMP_BUFFER.with(|buf| buf.get());
-        let prev_jmp_buf = *jmp_buf;
+            let jmp_buf = SETJMP_BUFFER.with(|buf| buf.get());
+            let prev_jmp_buf = *jmp_buf;
 
-        install_sighandler();
+            SIGHANDLER_INIT.call_once(|| {
+                install_sighandler();
+            });
 
-        let signum = setjmp(jmp_buf as *mut ::nix::libc::c_void);
-        if signum != 0 {
-            *jmp_buf = prev_jmp_buf;
-            let signal = match Signal::from_c_int(signum) {
-                Ok(SIGFPE) => "floating-point exception",
-                Ok(SIGILL) => "illegal instruction",
-                Ok(SIGSEGV) => "segmentation violation",
-                Ok(SIGBUS) => "bus error",
-                Err(_) => "error while getting the Signal",
-                _ => "unkown trapped signal",
-            };
-            Err(ErrorKind::RuntimeError(format!("trap - {}", signal)))
-        } else {
-            let ret = $x; // TODO: Switch stack?
-            *jmp_buf = prev_jmp_buf;
-            Ok(ret)
+            let signum = setjmp(jmp_buf as *mut ::nix::libc::c_void);
+            if signum != 0 {
+                *jmp_buf = prev_jmp_buf;
+                let signal = match Signal::from_c_int(signum) {
+                    Ok(SIGFPE) => "floating-point exception",
+                    Ok(SIGILL) => "illegal instruction",
+                    Ok(SIGSEGV) => "segmentation violation",
+                    Ok(SIGBUS) => "bus error",
+                    Err(_) => "error while getting the Signal",
+                    _ => "unkown trapped signal",
+                };
+                Err(ErrorKind::RuntimeError(format!("trap - {}", signal)))
+            } else {
+                let ret = $x; // TODO: Switch stack?
+                *jmp_buf = prev_jmp_buf;
+                Ok(ret)
+            }
         }
-    }}
+    };
 }
 
-
 /// Unwinds to last protected_call.
 pub unsafe fn do_unwind(signum: i32) -> ! {
     // Since do_unwind is only expected to get called from WebAssembly code which doesn't hold any host resources (locks etc.)

src/webassembly/instance.rs

@@ -22,7 +22,6 @@ use std::slice;
 use std::sync::Arc;
 
 use super::super::common::slice::{BoundedSlice, UncheckedSlice};
-use super::super::recovery;
 use super::errors::ErrorKind;
 use super::import_object::{ImportObject, ImportValue};
 use super::math_intrinsics;
@@ -481,12 +480,7 @@ impl Instance {
             tables.iter().map(|table| table[..].into()).collect();
         let memories_pointer: Vec<BoundedSlice<u8>> = memories
             .iter()
-            .map(|mem| {
-                BoundedSlice::new(
-                    &mem[..],
-                    mem.current_size(),
-                )
-            })
+            .map(|mem| BoundedSlice::new(&mem[..], mem.current_size()))
             .collect();
         let globals_pointer: GlobalsSlice = globals[..].into();
 
@@ -530,8 +524,7 @@ impl Instance {
         if let Some(func_index) = self.start_func {
             let func: fn(&Instance) = get_instance_function!(&self, func_index);
             call_protected!(func(self))
-        }
-        else {
+        } else {
             Ok(())
         }
     }