mikros/rust
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Squirrel away the JIT contexts into TLS when done

Browse Source 
This prevents attempting to run deallocated code (which is no longer present
always)
This commit is contained in:
Alex Crichton 2013-07-12 23:16:50 -07:00
parent 1ee54a8617
commit 48aa18d26a
1 changed files with 52 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

68
src/librustc/back/link.rs
View File

@ -101,15 +101,30 @@ pub mod jit {
use back::link::llvm_err;
use driver::session::Session;
use lib::llvm::llvm;
use lib::llvm::{ModuleRef, ContextRef};
use lib::llvm::{ModuleRef, ContextRef, ExecutionEngineRef};
use metadata::cstore;
use std::cast;
use std::ptr;
use std::str;
use std::sys;
use std::local_data;
use std::unstable::intrinsics;
struct LLVMJITData {
ee: ExecutionEngineRef,
llcx: ContextRef
}
pub trait Engine {}
impl Engine for LLVMJITData {}
impl Drop for LLVMJITData {
fn drop(&self) {
unsafe {
llvm::LLVMDisposeExecutionEngine(self.ee);
llvm::LLVMContextDispose(self.llcx);
}
}
}
pub fn exec(sess: Session,
c: ContextRef,
m: ModuleRef,
@ -130,7 +145,7 @@ pub mod jit {
debug!("linking: %s", path);
do str::as_c_str(path) |buf_t| {
do path.as_c_str |buf_t| {
if !llvm::LLVMRustLoadCrate(manager, buf_t) {
llvm_err(sess, ~"Could not link");
}
@ -149,7 +164,7 @@ pub mod jit {
// Next, we need to get a handle on the _rust_main function by
// looking up it's corresponding ValueRef and then requesting that
// the execution engine compiles the function.
let fun = do str::as_c_str("_rust_main") |entry| {
let fun = do "_rust_main".as_c_str |entry| {
llvm::LLVMGetNamedFunction(m, entry)
};
if fun.is_null() {
@ -163,20 +178,41 @@ pub mod jit {
// closure
let code = llvm::LLVMGetPointerToGlobal(ee, fun);
assert!(!code.is_null());
let closure = sys::Closure {
code: code,
env: ptr::null()
};
let func: &fn() = cast::transmute(closure);
let func: extern "Rust" fn() = cast::transmute(code);
func();
// Sadly, there currently is no interface to re-use this execution
// engine, so it's disposed of here along with the context to
// prevent leaks.
llvm::LLVMDisposeExecutionEngine(ee);
llvm::LLVMContextDispose(c);
// Currently there is no method of re-using the executing engine
// from LLVM in another call to the JIT. While this kinda defeats
// the purpose of having a JIT in the first place, there isn't
// actually much code currently which would re-use data between
// different invocations of this. Additionally, the compilation
// model currently isn't designed to support this scenario.
//
// We can't destroy the engine/context immediately here, however,
// because of annihilation. The JIT code contains drop glue for any
// types defined in the crate we just ran, and if any of those boxes
// are going to be dropped during annihilation, the drop glue must
// be run. Hence, we need to transfer ownership of this jit engine
// to the caller of this function. To be convenient for now, we
// shove it into TLS and have someone else remove it later on.
let data = ~LLVMJITData { ee: ee, llcx: c };
set_engine(data as ~Engine);
}
}
fn engine_key(_: ~Engine) {}
#[cfg(not(stage0))]
fn set_engine(engine: ~Engine) {
unsafe { local_data::set(engine_key, engine) }
}
#[cfg(stage0)]
fn set_engine(_: ~Engine) {}
#[cfg(not(stage0))]
pub fn consume_engine() -> Option<~Engine> {
unsafe { local_data::pop(engine_key) }
}
}
pub mod write {