rust/miri/lib.rs
Oliver Schneider 181851fc6b
Always allocate for globals
statics are rare and constants are copied anyway.
Reading from a constant should then yield a `ByVal` again if possible.
2017-08-08 17:09:26 +02:00

226 lines
7.1 KiB
Rust

#![feature(
i128_type,
rustc_private,
)]
// From rustc.
#[macro_use]
extern crate log;
extern crate log_settings;
#[macro_use]
extern crate rustc;
extern crate rustc_const_math;
extern crate rustc_data_structures;
extern crate syntax;
use rustc::ty::{self, TyCtxt};
use rustc::ty::layout::Layout;
use rustc::hir::def_id::DefId;
use rustc::mir;
use syntax::codemap::Span;
use std::collections::{
HashMap,
BTreeMap,
};
#[macro_use]
extern crate rustc_miri;
pub use rustc_miri::interpret::*;
mod fn_call;
mod operator;
mod intrinsic;
mod helpers;
mod memory;
mod tls;
use fn_call::EvalContextExt as MissingFnsEvalContextExt;
use operator::EvalContextExt as OperatorEvalContextExt;
use intrinsic::EvalContextExt as IntrinsicEvalContextExt;
use tls::EvalContextExt as TlsEvalContextExt;
pub fn eval_main<'a, 'tcx: 'a>(
tcx: TyCtxt<'a, 'tcx, 'tcx>,
main_id: DefId,
start_wrapper: Option<DefId>,
limits: ResourceLimits,
) {
fn run_main<'a, 'tcx: 'a>(
ecx: &mut rustc_miri::interpret::EvalContext<'a, 'tcx, Evaluator>,
main_id: DefId,
start_wrapper: Option<DefId>,
) -> EvalResult<'tcx> {
let main_instance = ty::Instance::mono(ecx.tcx, main_id);
let main_mir = ecx.load_mir(main_instance.def)?;
let mut cleanup_ptr = None; // Pointer to be deallocated when we are done
if !main_mir.return_ty.is_nil() || main_mir.arg_count != 0 {
return err!(Unimplemented("miri does not support main functions without `fn()` type signatures".to_owned()));
}
if let Some(start_id) = start_wrapper {
let start_instance = ty::Instance::mono(ecx.tcx, start_id);
let start_mir = ecx.load_mir(start_instance.def)?;
if start_mir.arg_count != 3 {
return err!(AbiViolation(format!("'start' lang item should have three arguments, but has {}", start_mir.arg_count)));
}
// Return value
let size = ecx.tcx.data_layout.pointer_size.bytes();
let align = ecx.tcx.data_layout.pointer_align.abi();
let ret_ptr = ecx.memory_mut().allocate(size, align, Kind::Stack)?;
cleanup_ptr = Some(ret_ptr);
// Push our stack frame
ecx.push_stack_frame(
start_instance,
start_mir.span,
start_mir,
Lvalue::from_ptr(ret_ptr),
StackPopCleanup::None,
)?;
let mut args = ecx.frame().mir.args_iter();
// First argument: pointer to main()
let main_ptr = ecx.memory_mut().create_fn_alloc(main_instance);
let dest = ecx.eval_lvalue(&mir::Lvalue::Local(args.next().unwrap()))?;
let main_ty = main_instance.def.def_ty(ecx.tcx);
let main_ptr_ty = ecx.tcx.mk_fn_ptr(main_ty.fn_sig(ecx.tcx));
ecx.write_value(Value::ByVal(PrimVal::Ptr(main_ptr)), dest, main_ptr_ty)?;
// Second argument (argc): 0
let dest = ecx.eval_lvalue(&mir::Lvalue::Local(args.next().unwrap()))?;
let ty = ecx.tcx.types.isize;
ecx.write_null(dest, ty)?;
// Third argument (argv): 0
let dest = ecx.eval_lvalue(&mir::Lvalue::Local(args.next().unwrap()))?;
let ty = ecx.tcx.mk_imm_ptr(ecx.tcx.mk_imm_ptr(ecx.tcx.types.u8));
ecx.write_null(dest, ty)?;
} else {
ecx.push_stack_frame(
main_instance,
main_mir.span,
main_mir,
Lvalue::undef(),
StackPopCleanup::None,
)?;
}
while ecx.step()? {}
ecx.run_tls_dtors()?;
if let Some(cleanup_ptr) = cleanup_ptr {
ecx.memory_mut().deallocate(cleanup_ptr, None, Kind::Stack)?;
}
Ok(())
}
let mut ecx = EvalContext::new(tcx, limits, Default::default(), Default::default());
match run_main(&mut ecx, main_id, start_wrapper) {
Ok(()) => {
let leaks = ecx.memory().leak_report();
if leaks != 0 {
tcx.sess.err("the evaluated program leaked memory");
}
}
Err(mut e) => {
ecx.report(&mut e);
}
}
}
struct Evaluator;
#[derive(Default)]
struct EvaluatorData {
/// Environment variables set by `setenv`
/// Miri does not expose env vars from the host to the emulated program
pub(crate) env_vars: HashMap<Vec<u8>, MemoryPointer>,
}
pub type TlsKey = usize;
#[derive(Copy, Clone, Debug)]
pub struct TlsEntry<'tcx> {
data: Pointer, // Will eventually become a map from thread IDs to `Pointer`s, if we ever support more than one thread.
dtor: Option<ty::Instance<'tcx>>,
}
#[derive(Default)]
struct MemoryData<'tcx> {
/// The Key to use for the next thread-local allocation.
next_thread_local: TlsKey,
/// pthreads-style thread-local storage.
thread_local: BTreeMap<TlsKey, TlsEntry<'tcx>>,
}
impl<'tcx> Machine<'tcx> for Evaluator {
type Data = EvaluatorData;
type MemoryData = MemoryData<'tcx>;
type MemoryKinds = memory::Kind;
/// Returns Ok() when the function was handled, fail otherwise
fn eval_fn_call<'a>(
ecx: &mut EvalContext<'a, 'tcx, Self>,
instance: ty::Instance<'tcx>,
destination: Option<(Lvalue, mir::BasicBlock)>,
arg_operands: &[mir::Operand<'tcx>],
span: Span,
sig: ty::FnSig<'tcx>,
) -> EvalResult<'tcx, bool> {
ecx.eval_fn_call(instance, destination, arg_operands, span, sig)
}
fn call_intrinsic<'a>(
ecx: &mut rustc_miri::interpret::EvalContext<'a, 'tcx, Self>,
instance: ty::Instance<'tcx>,
args: &[mir::Operand<'tcx>],
dest: Lvalue,
dest_ty: ty::Ty<'tcx>,
dest_layout: &'tcx Layout,
target: mir::BasicBlock,
) -> EvalResult<'tcx> {
ecx.call_intrinsic(instance, args, dest, dest_ty, dest_layout, target)
}
fn try_ptr_op<'a>(
ecx: &rustc_miri::interpret::EvalContext<'a, 'tcx, Self>,
bin_op: mir::BinOp,
left: PrimVal,
left_ty: ty::Ty<'tcx>,
right: PrimVal,
right_ty: ty::Ty<'tcx>,
) -> EvalResult<'tcx, Option<(PrimVal, bool)>> {
ecx.ptr_op(bin_op, left, left_ty, right, right_ty)
}
fn mark_static_initialized(m: memory::Kind) -> EvalResult<'tcx> {
use memory::Kind::*;
match m {
// FIXME: This could be allowed, but not for env vars set during miri execution
Env => err!(Unimplemented("statics can't refer to env vars".to_owned())),
_ => Ok(()),
}
}
fn box_alloc<'a>(
ecx: &mut EvalContext<'a, 'tcx, Self>,
ty: ty::Ty<'tcx>,
) -> EvalResult<'tcx, PrimVal> {
// FIXME: call the `exchange_malloc` lang item if available
let size = ecx.type_size(ty)?.expect("box only works with sized types");
let align = ecx.type_align(ty)?;
if size == 0 {
Ok(PrimVal::Bytes(align.into()))
} else {
ecx.memory
.allocate(size, align, Kind::Machine(memory::Kind::Rust))
.map(PrimVal::Ptr)
}
}
}