+++ /dev/null
-use rustc::middle::const_val;
-use rustc::hir::def_id::DefId;
-use rustc::mir::mir_map::MirMap;
-use rustc::mir::repr as mir;
-use rustc::traits::{self, ProjectionMode};
-use rustc::ty::fold::TypeFoldable;
-use rustc::ty::layout::{self, Layout, Size};
-use rustc::ty::subst::{self, Subst, Substs};
-use rustc::ty::{self, Ty, TyCtxt};
-use rustc::util::nodemap::DefIdMap;
-use std::cell::RefCell;
-use std::ops::{Deref, DerefMut};
-use std::rc::Rc;
-use std::{iter, mem};
-use syntax::ast;
-use syntax::attr;
-use syntax::codemap::{self, DUMMY_SP};
-
-use error::{EvalError, EvalResult};
-use memory::{Memory, Pointer};
-use primval::{self, PrimVal};
-
-struct GlobalEvalContext<'a, 'tcx: 'a> {
- /// The results of the type checker, from rustc.
- tcx: TyCtxt<'a, 'tcx, 'tcx>,
-
- /// A mapping from NodeIds to Mir, from rustc. Only contains MIR for crate-local items.
- mir_map: &'a MirMap<'tcx>,
-
- /// A local cache from DefIds to Mir for non-crate-local items.
- mir_cache: RefCell<DefIdMap<Rc<mir::Mir<'tcx>>>>,
-
- /// The virtual memory system.
- memory: Memory,
-
- /// Another stack containing the type substitutions for the current function invocation. It
- /// exists separately from `stack` because it must contain the `Substs` for a function while
- /// *creating* the `Frame` for that same function.
- substs_stack: Vec<&'tcx Substs<'tcx>>,
-
- // TODO(solson): Merge with `substs_stack`. Also try restructuring `Frame` to accomodate.
- /// A stack of the things necessary to print good strack traces:
- /// * Function DefIds and Substs to print proper substituted function names.
- /// * Spans pointing to specific function calls in the source.
- name_stack: Vec<(DefId, &'tcx Substs<'tcx>, codemap::Span)>,
-}
-
-struct FnEvalContext<'a, 'b: 'a + 'mir, 'mir, 'tcx: 'b> {
- gecx: &'a mut GlobalEvalContext<'b, 'tcx>,
-
- /// The virtual call stack.
- stack: Vec<Frame<'mir, 'tcx>>,
-}
-
-impl<'a, 'b, 'mir, 'tcx> Deref for FnEvalContext<'a, 'b, 'mir, 'tcx> {
- type Target = GlobalEvalContext<'b, 'tcx>;
- fn deref(&self) -> &Self::Target {
- self.gecx
- }
-}
-
-impl<'a, 'b, 'mir, 'tcx> DerefMut for FnEvalContext<'a, 'b, 'mir, 'tcx> {
- fn deref_mut(&mut self) -> &mut Self::Target {
- self.gecx
- }
-}
-
-/// A stack frame.
-struct Frame<'a, 'tcx: 'a> {
- /// The MIR for the function called on this frame.
- mir: CachedMir<'a, 'tcx>,
-
- /// The block this frame will execute when a function call returns back to this frame.
- next_block: mir::BasicBlock,
-
- /// A pointer for writing the return value of the current call if it's not a diverging call.
- return_ptr: Option<Pointer>,
-
- /// The list of locals for the current function, stored in order as
- /// `[arguments..., variables..., temporaries...]`. The variables begin at `self.var_offset`
- /// and the temporaries at `self.temp_offset`.
- locals: Vec<Pointer>,
-
- /// The offset of the first variable in `self.locals`.
- var_offset: usize,
-
- /// The offset of the first temporary in `self.locals`.
- temp_offset: usize,
-}
-
-#[derive(Copy, Clone, Debug, Eq, PartialEq)]
-struct Lvalue {
- ptr: Pointer,
- extra: LvalueExtra,
-}
-
-#[derive(Copy, Clone, Debug, Eq, PartialEq)]
-enum LvalueExtra {
- None,
- Length(u64),
- // TODO(solson): Vtable(memory::AllocId),
- DowncastVariant(usize),
-}
-
-#[derive(Clone)]
-enum CachedMir<'mir, 'tcx: 'mir> {
- Ref(&'mir mir::Mir<'tcx>),
- Owned(Rc<mir::Mir<'tcx>>)
-}
-
-/// Represents the action to be taken in the main loop as a result of executing a terminator.
-enum TerminatorTarget {
- /// Make a local jump to the given block.
- Block(mir::BasicBlock),
-
- /// Start executing from the new current frame. (For function calls.)
- Call,
-
- /// Stop executing the current frame and resume the previous frame.
- Return,
-}
-
-impl<'a, 'tcx> GlobalEvalContext<'a, 'tcx> {
- fn new(tcx: TyCtxt<'a, 'tcx, 'tcx>, mir_map: &'a MirMap<'tcx>) -> Self {
- GlobalEvalContext {
- tcx: tcx,
- mir_map: mir_map,
- mir_cache: RefCell::new(DefIdMap()),
- memory: Memory::new(tcx.sess
- .target
- .uint_type
- .bit_width()
- .expect("Session::target::uint_type was usize")/8),
- substs_stack: Vec::new(),
- name_stack: Vec::new(),
- }
- }
-
- fn call(&mut self, mir: &mir::Mir<'tcx>) -> EvalResult<Option<Pointer>> {
- let mut nested_fecx = FnEvalContext::new(self);
-
- let return_ptr = match mir.return_ty {
- ty::FnConverging(ty) => {
- let size = nested_fecx.type_size(ty);
- Some(nested_fecx.memory.allocate(size))
- }
- ty::FnDiverging => None,
- };
-
- let substs = nested_fecx.substs();
- nested_fecx.push_stack_frame(CachedMir::Ref(mir), substs, return_ptr);
- nested_fecx.run()?;
- Ok(return_ptr)
- }
-}
-
-impl<'a, 'b, 'mir, 'tcx> FnEvalContext<'a, 'b, 'mir, 'tcx> {
- fn new(gecx: &'a mut GlobalEvalContext<'b, 'tcx>) -> Self {
- FnEvalContext {
- gecx: gecx,
- stack: Vec::new(),
- }
- }
-
- fn maybe_report<T>(&self, span: codemap::Span, r: EvalResult<T>) -> EvalResult<T> {
- if let Err(ref e) = r {
- let mut err = self.tcx.sess.struct_span_err(span, &e.to_string());
- for &(def_id, substs, span) in self.name_stack.iter().rev() {
- // FIXME(solson): Find a way to do this without this Display impl hack.
- use rustc::util::ppaux;
- use std::fmt;
- struct Instance<'tcx>(DefId, &'tcx Substs<'tcx>);
- impl<'tcx> fmt::Display for Instance<'tcx> {
- fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
- ppaux::parameterized(f, self.1, self.0, ppaux::Ns::Value, &[],
- |tcx| tcx.lookup_item_type(self.0).generics)
- }
- }
- err.span_note(span, &format!("inside call to {}", Instance(def_id, substs)));
- }
- err.emit();
- }
- r
- }
-
- fn run(&mut self) -> EvalResult<()> {
- 'outer: while !self.stack.is_empty() {
- let mut current_block = self.frame().next_block;
- let current_mir = self.mir();
-
- loop {
- trace!("// {:?}", current_block);
- let block_data = current_mir.basic_block_data(current_block);
-
- for stmt in &block_data.statements {
- trace!("{:?}", stmt);
- let mir::StatementKind::Assign(ref lvalue, ref rvalue) = stmt.kind;
- let result = self.eval_assignment(lvalue, rvalue);
- self.maybe_report(stmt.span, result)?;
- }
-
- let terminator = block_data.terminator();
- trace!("{:?}", terminator.kind);
-
- let result = self.eval_terminator(terminator);
- match self.maybe_report(terminator.span, result)? {
- TerminatorTarget::Block(block) => current_block = block,
- TerminatorTarget::Return => {
- self.pop_stack_frame();
- self.name_stack.pop();
- continue 'outer;
- }
- TerminatorTarget::Call => continue 'outer,
- }
- }
- }
-
- Ok(())
- }
-
- fn push_stack_frame(&mut self, mir: CachedMir<'mir, 'tcx>, substs: &'tcx Substs<'tcx>,
- return_ptr: Option<Pointer>)
- {
- self.substs_stack.push(substs);
-
- let arg_tys = mir.arg_decls.iter().map(|a| a.ty);
- let var_tys = mir.var_decls.iter().map(|v| v.ty);
- let temp_tys = mir.temp_decls.iter().map(|t| t.ty);
-
- let locals: Vec<Pointer> = arg_tys.chain(var_tys).chain(temp_tys).map(|ty| {
- let size = self.type_size(ty);
- self.memory.allocate(size)
- }).collect();
-
- let num_args = mir.arg_decls.len();
- let num_vars = mir.var_decls.len();
-
- ::log_settings::settings().indentation += 1;
-
- self.stack.push(Frame {
- mir: mir.clone(),
- next_block: mir::START_BLOCK,
- return_ptr: return_ptr,
- locals: locals,
- var_offset: num_args,
- temp_offset: num_args + num_vars,
- });
- }
-
- fn pop_stack_frame(&mut self) {
- ::log_settings::settings().indentation -= 1;
- let _frame = self.stack.pop().expect("tried to pop a stack frame, but there were none");
- // TODO(solson): Deallocate local variables.
- self.substs_stack.pop();
- }
-
- fn eval_terminator(&mut self, terminator: &mir::Terminator<'tcx>)
- -> EvalResult<TerminatorTarget> {
- use rustc::mir::repr::TerminatorKind::*;
- let target = match terminator.kind {
- Return => TerminatorTarget::Return,
-
- Goto { target } => TerminatorTarget::Block(target),
-
- If { ref cond, targets: (then_target, else_target) } => {
- let cond_ptr = self.eval_operand(cond)?;
- let cond_val = self.memory.read_bool(cond_ptr)?;
- TerminatorTarget::Block(if cond_val { then_target } else { else_target })
- }
-
- SwitchInt { ref discr, ref values, ref targets, .. } => {
- let discr_ptr = self.eval_lvalue(discr)?.to_ptr();
- let discr_size = self
- .type_layout(self.lvalue_ty(discr))
- .size(&self.tcx.data_layout)
- .bytes() as usize;
- let discr_val = self.memory.read_uint(discr_ptr, discr_size)?;
-
- // Branch to the `otherwise` case by default, if no match is found.
- let mut target_block = targets[targets.len() - 1];
-
- for (index, val_const) in values.iter().enumerate() {
- let ptr = self.const_to_ptr(val_const)?;
- let val = self.memory.read_uint(ptr, discr_size)?;
- if discr_val == val {
- target_block = targets[index];
- break;
- }
- }
-
- TerminatorTarget::Block(target_block)
- }
-
- Switch { ref discr, ref targets, adt_def } => {
- let adt_ptr = self.eval_lvalue(discr)?.to_ptr();
- let adt_ty = self.lvalue_ty(discr);
- let discr_val = self.read_discriminant_value(adt_ptr, adt_ty)?;
- let matching = adt_def.variants.iter()
- .position(|v| discr_val == v.disr_val.to_u64_unchecked());
-
- match matching {
- Some(i) => TerminatorTarget::Block(targets[i]),
- None => return Err(EvalError::InvalidDiscriminant),
- }
- }
-
- Call { ref func, ref args, ref destination, .. } => {
- let mut return_ptr = None;
- if let Some((ref lv, target)) = *destination {
- self.frame_mut().next_block = target;
- return_ptr = Some(self.eval_lvalue(lv)?.to_ptr());
- }
-
- let func_ty = self.operand_ty(func);
- match func_ty.sty {
- ty::TyFnDef(def_id, substs, fn_ty) => {
- use syntax::abi::Abi;
- match fn_ty.abi {
- Abi::RustIntrinsic => {
- let name = self.tcx.item_name(def_id).as_str();
- match fn_ty.sig.0.output {
- ty::FnConverging(ty) => {
- let size = self.type_size(ty);
- let ret = return_ptr.unwrap();
- self.call_intrinsic(&name, substs, args, ret, size)?
- }
- ty::FnDiverging => unimplemented!(),
- }
- }
-
- Abi::C => {
- match fn_ty.sig.0.output {
- ty::FnConverging(ty) => {
- let size = self.type_size(ty);
- self.call_c_abi(def_id, args, return_ptr.unwrap(), size)?
- }
- ty::FnDiverging => unimplemented!(),
- }
- }
-
- Abi::Rust | Abi::RustCall => {
- // TODO(solson): Adjust the first argument when calling a Fn or
- // FnMut closure via FnOnce::call_once.
-
- // Only trait methods can have a Self parameter.
- let (resolved_def_id, resolved_substs) = if substs.self_ty().is_some() {
- self.trait_method(def_id, substs)
- } else {
- (def_id, substs)
- };
-
- let mut arg_srcs = Vec::new();
- for arg in args {
- let src = self.eval_operand(arg)?;
- let src_ty = self.operand_ty(arg);
- arg_srcs.push((src, src_ty));
- }
-
- if fn_ty.abi == Abi::RustCall && !args.is_empty() {
- arg_srcs.pop();
- let last_arg = args.last().unwrap();
- let last = self.eval_operand(last_arg)?;
- let last_ty = self.operand_ty(last_arg);
- let last_layout = self.type_layout(last_ty);
- match (&last_ty.sty, last_layout) {
- (&ty::TyTuple(fields),
- &Layout::Univariant { ref variant, .. }) => {
- let offsets = iter::once(0)
- .chain(variant.offset_after_field.iter()
- .map(|s| s.bytes()));
- for (offset, ty) in offsets.zip(fields) {
- let src = last.offset(offset as isize);
- arg_srcs.push((src, ty));
- }
- }
- ty => panic!("expected tuple as last argument in function with 'rust-call' ABI, got {:?}", ty),
- }
- }
-
- let mir = self.load_mir(resolved_def_id);
- self.name_stack.push((def_id, substs, terminator.span));
- self.push_stack_frame(mir, resolved_substs, return_ptr);
-
- for (i, (src, src_ty)) in arg_srcs.into_iter().enumerate() {
- let dest = self.frame().locals[i];
- self.move_(src, dest, src_ty)?;
- }
-
- TerminatorTarget::Call
- }
-
- abi => return Err(EvalError::Unimplemented(format!("can't handle function with {:?} ABI", abi))),
- }
- }
-
- _ => return Err(EvalError::Unimplemented(format!("can't handle callee of type {:?}", func_ty))),
- }
- }
-
- Drop { ref value, target, .. } => {
- let ptr = self.eval_lvalue(value)?.to_ptr();
- let ty = self.lvalue_ty(value);
- self.drop(ptr, ty)?;
- TerminatorTarget::Block(target)
- }
-
- Resume => unimplemented!(),
- };
-
- Ok(target)
- }
-
- fn drop(&mut self, ptr: Pointer, ty: Ty<'tcx>) -> EvalResult<()> {
- if !self.type_needs_drop(ty) {
- debug!("no need to drop {:?}", ty);
- return Ok(());
- }
- trace!("-need to drop {:?}", ty);
-
- // TODO(solson): Call user-defined Drop::drop impls.
-
- match ty.sty {
- ty::TyBox(contents_ty) => {
- match self.memory.read_ptr(ptr) {
- Ok(contents_ptr) => {
- self.drop(contents_ptr, contents_ty)?;
- trace!("-deallocating box");
- self.memory.deallocate(contents_ptr)?;
- }
- Err(EvalError::ReadBytesAsPointer) => {
- let size = self.memory.pointer_size;
- let possible_drop_fill = self.memory.read_bytes(ptr, size)?;
- if possible_drop_fill.iter().all(|&b| b == mem::POST_DROP_U8) {
- return Ok(());
- } else {
- return Err(EvalError::ReadBytesAsPointer);
- }
- }
- Err(e) => return Err(e),
- }
- }
-
- // TODO(solson): Implement drop for other relevant types (e.g. aggregates).
- _ => {}
- }
-
- // Filling drop.
- // FIXME(solson): Trait objects (with no static size) probably get filled, too.
- let size = self.type_size(ty);
- self.memory.drop_fill(ptr, size)?;
-
- Ok(())
- }
-
- fn read_discriminant_value(&self, adt_ptr: Pointer, adt_ty: Ty<'tcx>) -> EvalResult<u64> {
- use rustc::ty::layout::Layout::*;
- let adt_layout = self.type_layout(adt_ty);
-
- let discr_val = match *adt_layout {
- General { discr, .. } | CEnum { discr, .. } => {
- let discr_size = discr.size().bytes();
- self.memory.read_uint(adt_ptr, discr_size as usize)?
- }
-
- RawNullablePointer { nndiscr, .. } => {
- self.read_nonnull_discriminant_value(adt_ptr, nndiscr)?
- }
-
- StructWrappedNullablePointer { nndiscr, ref discrfield, .. } => {
- let offset = self.nonnull_offset(adt_ty, nndiscr, discrfield)?;
- let nonnull = adt_ptr.offset(offset.bytes() as isize);
- self.read_nonnull_discriminant_value(nonnull, nndiscr)?
- }
-
- // The discriminant_value intrinsic returns 0 for non-sum types.
- Array { .. } | FatPointer { .. } | Scalar { .. } | Univariant { .. } |
- Vector { .. } => 0,
- };
-
- Ok(discr_val)
- }
-
- fn read_nonnull_discriminant_value(&self, ptr: Pointer, nndiscr: u64) -> EvalResult<u64> {
- let not_null = match self.memory.read_usize(ptr) {
- Ok(0) => false,
- Ok(_) | Err(EvalError::ReadPointerAsBytes) => true,
- Err(e) => return Err(e),
- };
- assert!(nndiscr == 0 || nndiscr == 1);
- Ok(if not_null { nndiscr } else { 1 - nndiscr })
- }
-
- fn call_intrinsic(
- &mut self,
- name: &str,
- substs: &'tcx Substs<'tcx>,
- args: &[mir::Operand<'tcx>],
- dest: Pointer,
- dest_size: usize
- ) -> EvalResult<TerminatorTarget> {
- let args_res: EvalResult<Vec<Pointer>> = args.iter()
- .map(|arg| self.eval_operand(arg))
- .collect();
- let args = args_res?;
-
- match name {
- // FIXME(solson): Handle different integer types correctly.
- "add_with_overflow" => {
- let ty = *substs.types.get(subst::FnSpace, 0);
- let size = self.type_size(ty);
- let left = self.memory.read_int(args[0], size)?;
- let right = self.memory.read_int(args[1], size)?;
- let (n, overflowed) = unsafe {
- ::std::intrinsics::add_with_overflow::<i64>(left, right)
- };
- self.memory.write_int(dest, n, size)?;
- self.memory.write_bool(dest.offset(size as isize), overflowed)?;
- }
-
- "assume" => {}
-
- "copy_nonoverlapping" => {
- let elem_ty = *substs.types.get(subst::FnSpace, 0);
- let elem_size = self.type_size(elem_ty);
- let src = self.memory.read_ptr(args[0])?;
- let dest = self.memory.read_ptr(args[1])?;
- let count = self.memory.read_isize(args[2])?;
- self.memory.copy(src, dest, count as usize * elem_size)?;
- }
-
- "discriminant_value" => {
- let ty = *substs.types.get(subst::FnSpace, 0);
- let adt_ptr = self.memory.read_ptr(args[0])?;
- let discr_val = self.read_discriminant_value(adt_ptr, ty)?;
- self.memory.write_uint(dest, discr_val, dest_size)?;
- }
-
- "forget" => {
- let arg_ty = *substs.types.get(subst::FnSpace, 0);
- let arg_size = self.type_size(arg_ty);
- self.memory.drop_fill(args[0], arg_size)?;
- }
-
- "init" => self.memory.write_repeat(dest, 0, dest_size)?,
-
- "min_align_of" => {
- self.memory.write_int(dest, 1, dest_size)?;
- }
-
- "move_val_init" => {
- let ty = *substs.types.get(subst::FnSpace, 0);
- let ptr = self.memory.read_ptr(args[0])?;
- self.move_(args[1], ptr, ty)?;
- }
-
- // FIXME(solson): Handle different integer types correctly.
- "mul_with_overflow" => {
- let ty = *substs.types.get(subst::FnSpace, 0);
- let size = self.type_size(ty);
- let left = self.memory.read_int(args[0], size)?;
- let right = self.memory.read_int(args[1], size)?;
- let (n, overflowed) = unsafe {
- ::std::intrinsics::mul_with_overflow::<i64>(left, right)
- };
- self.memory.write_int(dest, n, size)?;
- self.memory.write_bool(dest.offset(size as isize), overflowed)?;
- }
-
- "offset" => {
- let pointee_ty = *substs.types.get(subst::FnSpace, 0);
- let pointee_size = self.type_size(pointee_ty) as isize;
- let ptr_arg = args[0];
- let offset = self.memory.read_isize(args[1])?;
-
- match self.memory.read_ptr(ptr_arg) {
- Ok(ptr) => {
- let result_ptr = ptr.offset(offset as isize * pointee_size);
- self.memory.write_ptr(dest, result_ptr)?;
- }
- Err(EvalError::ReadBytesAsPointer) => {
- let addr = self.memory.read_isize(ptr_arg)?;
- let result_addr = addr + offset * pointee_size as i64;
- self.memory.write_isize(dest, result_addr)?;
- }
- Err(e) => return Err(e),
- }
- }
-
- // FIXME(solson): Handle different integer types correctly. Use primvals?
- "overflowing_sub" => {
- let ty = *substs.types.get(subst::FnSpace, 0);
- let size = self.type_size(ty);
- let left = self.memory.read_int(args[0], size)?;
- let right = self.memory.read_int(args[1], size)?;
- let n = left.wrapping_sub(right);
- self.memory.write_int(dest, n, size)?;
- }
-
- "size_of" => {
- let ty = *substs.types.get(subst::FnSpace, 0);
- let size = self.type_size(ty) as u64;
- self.memory.write_uint(dest, size, dest_size)?;
- }
-
- "size_of_val" => {
- let ty = *substs.types.get(subst::FnSpace, 0);
- if self.type_is_sized(ty) {
- let size = self.type_size(ty) as u64;
- self.memory.write_uint(dest, size, dest_size)?;
- } else {
- match ty.sty {
- ty::TySlice(_) | ty::TyStr => {
- let elem_ty = ty.sequence_element_type(self.tcx);
- let elem_size = self.type_size(elem_ty) as u64;
- let ptr_size = self.memory.pointer_size as isize;
- let n = self.memory.read_usize(args[0].offset(ptr_size))?;
- self.memory.write_uint(dest, n * elem_size, dest_size)?;
- }
-
- _ => return Err(EvalError::Unimplemented(format!("unimplemented: size_of_val::<{:?}>", ty))),
- }
- }
- }
-
- "transmute" => {
- let ty = *substs.types.get(subst::FnSpace, 0);
- self.move_(args[0], dest, ty)?;
- }
- "uninit" => self.memory.mark_definedness(dest, dest_size, false)?,
-
- name => return Err(EvalError::Unimplemented(format!("unimplemented intrinsic: {}", name))),
- }
-
- // Since we pushed no stack frame, the main loop will act
- // as if the call just completed and it's returning to the
- // current frame.
- Ok(TerminatorTarget::Call)
- }
-
- fn call_c_abi(
- &mut self,
- def_id: DefId,
- args: &[mir::Operand<'tcx>],
- dest: Pointer,
- dest_size: usize,
- ) -> EvalResult<TerminatorTarget> {
- let name = self.tcx.item_name(def_id);
- let attrs = self.tcx.get_attrs(def_id);
- let link_name = match attr::first_attr_value_str_by_name(&attrs, "link_name") {
- Some(ln) => ln.clone(),
- None => name.as_str(),
- };
-
- let args_res: EvalResult<Vec<Pointer>> = args.iter()
- .map(|arg| self.eval_operand(arg))
- .collect();
- let args = args_res?;
-
- match &link_name[..] {
- "__rust_allocate" => {
- let size = self.memory.read_usize(args[0])?;
- let ptr = self.memory.allocate(size as usize);
- self.memory.write_ptr(dest, ptr)?;
- }
-
- "__rust_reallocate" => {
- let ptr = self.memory.read_ptr(args[0])?;
- let size = self.memory.read_usize(args[2])?;
- self.memory.reallocate(ptr, size as usize)?;
- self.memory.write_ptr(dest, ptr)?;
- }
-
- "memcmp" => {
- let left = self.memory.read_ptr(args[0])?;
- let right = self.memory.read_ptr(args[1])?;
- let n = self.memory.read_usize(args[2])? as usize;
-
- let result = {
- let left_bytes = self.memory.read_bytes(left, n)?;
- let right_bytes = self.memory.read_bytes(right, n)?;
-
- use std::cmp::Ordering::*;
- match left_bytes.cmp(right_bytes) {
- Less => -1,
- Equal => 0,
- Greater => 1,
- }
- };
-
- self.memory.write_int(dest, result, dest_size)?;
- }
-
- _ => return Err(EvalError::Unimplemented(format!("can't call C ABI function: {}", link_name))),
- }
-
- // Since we pushed no stack frame, the main loop will act
- // as if the call just completed and it's returning to the
- // current frame.
- Ok(TerminatorTarget::Call)
- }
-
- fn assign_fields<I: IntoIterator<Item = u64>>(
- &mut self,
- dest: Pointer,
- offsets: I,
- operands: &[mir::Operand<'tcx>],
- ) -> EvalResult<()> {
- for (offset, operand) in offsets.into_iter().zip(operands) {
- let src = self.eval_operand(operand)?;
- let src_ty = self.operand_ty(operand);
- let field_dest = dest.offset(offset as isize);
- self.move_(src, field_dest, src_ty)?;
- }
- Ok(())
- }
-
- fn eval_assignment(&mut self, lvalue: &mir::Lvalue<'tcx>, rvalue: &mir::Rvalue<'tcx>)
- -> EvalResult<()>
- {
- let dest = self.eval_lvalue(lvalue)?.to_ptr();
- let dest_ty = self.lvalue_ty(lvalue);
- let dest_layout = self.type_layout(dest_ty);
-
- use rustc::mir::repr::Rvalue::*;
- match *rvalue {
- Use(ref operand) => {
- let src = self.eval_operand(operand)?;
- self.move_(src, dest, dest_ty)?;
- }
-
- BinaryOp(bin_op, ref left, ref right) => {
- let left_ptr = self.eval_operand(left)?;
- let left_ty = self.operand_ty(left);
- let left_val = self.read_primval(left_ptr, left_ty)?;
-
- let right_ptr = self.eval_operand(right)?;
- let right_ty = self.operand_ty(right);
- let right_val = self.read_primval(right_ptr, right_ty)?;
-
- let val = primval::binary_op(bin_op, left_val, right_val)?;
- self.memory.write_primval(dest, val)?;
- }
-
- UnaryOp(un_op, ref operand) => {
- let ptr = self.eval_operand(operand)?;
- let ty = self.operand_ty(operand);
- let val = self.read_primval(ptr, ty)?;
- self.memory.write_primval(dest, primval::unary_op(un_op, val)?)?;
- }
-
- Aggregate(ref kind, ref operands) => {
- use rustc::ty::layout::Layout::*;
- match *dest_layout {
- Univariant { ref variant, .. } => {
- let offsets = iter::once(0)
- .chain(variant.offset_after_field.iter().map(|s| s.bytes()));
- self.assign_fields(dest, offsets, operands)?;
- }
-
- Array { .. } => {
- let elem_size = match dest_ty.sty {
- ty::TyArray(elem_ty, _) => self.type_size(elem_ty) as u64,
- _ => panic!("tried to assign {:?} to non-array type {:?}",
- kind, dest_ty),
- };
- let offsets = (0..).map(|i| i * elem_size);
- self.assign_fields(dest, offsets, operands)?;
- }
-
- General { discr, ref variants, .. } => {
- if let mir::AggregateKind::Adt(adt_def, variant, _) = *kind {
- let discr_val = adt_def.variants[variant].disr_val.to_u64_unchecked();
- let discr_size = discr.size().bytes() as usize;
- self.memory.write_uint(dest, discr_val, discr_size)?;
-
- let offsets = variants[variant].offset_after_field.iter()
- .map(|s| s.bytes());
- self.assign_fields(dest, offsets, operands)?;
- } else {
- panic!("tried to assign {:?} to Layout::General", kind);
- }
- }
-
- RawNullablePointer { nndiscr, .. } => {
- if let mir::AggregateKind::Adt(_, variant, _) = *kind {
- if nndiscr == variant as u64 {
- assert_eq!(operands.len(), 1);
- let operand = &operands[0];
- let src = self.eval_operand(operand)?;
- let src_ty = self.operand_ty(operand);
- self.move_(src, dest, src_ty)?;
- } else {
- assert_eq!(operands.len(), 0);
- self.memory.write_isize(dest, 0)?;
- }
- } else {
- panic!("tried to assign {:?} to Layout::RawNullablePointer", kind);
- }
- }
-
- StructWrappedNullablePointer { nndiscr, ref nonnull, ref discrfield } => {
- if let mir::AggregateKind::Adt(_, variant, _) = *kind {
- if nndiscr == variant as u64 {
- let offsets = iter::once(0)
- .chain(nonnull.offset_after_field.iter().map(|s| s.bytes()));
- try!(self.assign_fields(dest, offsets, operands));
- } else {
- assert_eq!(operands.len(), 0);
- let offset = self.nonnull_offset(dest_ty, nndiscr, discrfield)?;
- let dest = dest.offset(offset.bytes() as isize);
- try!(self.memory.write_isize(dest, 0));
- }
- } else {
- panic!("tried to assign {:?} to Layout::RawNullablePointer", kind);
- }
- }
-
- CEnum { discr, signed, .. } => {
- assert_eq!(operands.len(), 0);
- if let mir::AggregateKind::Adt(adt_def, variant, _) = *kind {
- let val = adt_def.variants[variant].disr_val.to_u64_unchecked();
- let size = discr.size().bytes() as usize;
-
- if signed {
- self.memory.write_int(dest, val as i64, size)?;
- } else {
- self.memory.write_uint(dest, val, size)?;
- }
- } else {
- panic!("tried to assign {:?} to Layout::CEnum", kind);
- }
- }
-
- _ => return Err(EvalError::Unimplemented(format!("can't handle destination layout {:?} when assigning {:?}", dest_layout, kind))),
- }
- }
-
- Repeat(ref operand, _) => {
- let (elem_size, length) = match dest_ty.sty {
- ty::TyArray(elem_ty, n) => (self.type_size(elem_ty), n),
- _ => panic!("tried to assign array-repeat to non-array type {:?}", dest_ty),
- };
-
- let src = self.eval_operand(operand)?;
- for i in 0..length {
- let elem_dest = dest.offset((i * elem_size) as isize);
- self.memory.copy(src, elem_dest, elem_size)?;
- }
- }
-
- Len(ref lvalue) => {
- let src = self.eval_lvalue(lvalue)?;
- let ty = self.lvalue_ty(lvalue);
- let len = match ty.sty {
- ty::TyArray(_, n) => n as u64,
- ty::TySlice(_) => if let LvalueExtra::Length(n) = src.extra {
- n
- } else {
- panic!("Rvalue::Len of a slice given non-slice pointer: {:?}", src);
- },
- _ => panic!("Rvalue::Len expected array or slice, got {:?}", ty),
- };
- self.memory.write_usize(dest, len)?;
- }
-
- Ref(_, _, ref lvalue) => {
- let lv = self.eval_lvalue(lvalue)?;
- self.memory.write_ptr(dest, lv.ptr)?;
- match lv.extra {
- LvalueExtra::None => {},
- LvalueExtra::Length(len) => {
- let len_ptr = dest.offset(self.memory.pointer_size as isize);
- self.memory.write_usize(len_ptr, len)?;
- }
- LvalueExtra::DowncastVariant(..) =>
- panic!("attempted to take a reference to an enum downcast lvalue"),
- }
- }
-
- Box(ty) => {
- let size = self.type_size(ty);
- let ptr = self.memory.allocate(size);
- self.memory.write_ptr(dest, ptr)?;
- }
-
- Cast(kind, ref operand, dest_ty) => {
- let src = self.eval_operand(operand)?;
- let src_ty = self.operand_ty(operand);
-
- use rustc::mir::repr::CastKind::*;
- match kind {
- Unsize => {
- self.move_(src, dest, src_ty)?;
- let src_pointee_ty = pointee_type(src_ty).unwrap();
- let dest_pointee_ty = pointee_type(dest_ty).unwrap();
-
- match (&src_pointee_ty.sty, &dest_pointee_ty.sty) {
- (&ty::TyArray(_, length), &ty::TySlice(_)) => {
- let len_ptr = dest.offset(self.memory.pointer_size as isize);
- self.memory.write_usize(len_ptr, length as u64)?;
- }
-
- _ => return Err(EvalError::Unimplemented(format!("can't handle cast: {:?}", rvalue))),
- }
- }
-
- Misc => {
- // FIXME(solson): Wrong for almost everything.
- let size = dest_layout.size(&self.tcx.data_layout).bytes() as usize;
- self.memory.copy(src, dest, size)?;
- }
-
- _ => return Err(EvalError::Unimplemented(format!("can't handle cast: {:?}", rvalue))),
- }
- }
-
- Slice { .. } => unimplemented!(),
- InlineAsm { .. } => unimplemented!(),
- }
-
- Ok(())
- }
-
- fn nonnull_offset(&self, ty: Ty<'tcx>, nndiscr: u64, discrfield: &[u32]) -> EvalResult<Size> {
- // Skip the constant 0 at the start meant for LLVM GEP.
- let mut path = discrfield.iter().skip(1).map(|&i| i as usize);
-
- // Handle the field index for the outer non-null variant.
- let inner_ty = match ty.sty {
- ty::TyEnum(adt_def, substs) => {
- let variant = &adt_def.variants[nndiscr as usize];
- let index = path.next().unwrap();
- let field = &variant.fields[index];
- field.ty(self.tcx, substs)
- }
- _ => panic!(
- "non-enum for StructWrappedNullablePointer: {}",
- ty,
- ),
- };
-
- self.field_path_offset(inner_ty, path)
- }
-
- fn field_path_offset<I: Iterator<Item = usize>>(&self, mut ty: Ty<'tcx>, path: I) -> EvalResult<Size> {
- let mut offset = Size::from_bytes(0);
-
- // Skip the initial 0 intended for LLVM GEP.
- for field_index in path {
- let field_offset = self.get_field_offset(ty, field_index)?;
- ty = self.get_field_ty(ty, field_index)?;
- offset = offset.checked_add(field_offset, &self.tcx.data_layout).unwrap();
- }
-
- Ok(offset)
- }
-
- fn get_field_ty(&self, ty: Ty<'tcx>, field_index: usize) -> EvalResult<Ty<'tcx>> {
- match ty.sty {
- ty::TyStruct(adt_def, substs) => {
- Ok(adt_def.struct_variant().fields[field_index].ty(self.tcx, substs))
- }
-
- ty::TyRef(_, ty::TypeAndMut { ty, .. }) |
- ty::TyRawPtr(ty::TypeAndMut { ty, .. }) |
- ty::TyBox(ty) => {
- assert_eq!(field_index, 0);
- Ok(ty)
- }
- _ => Err(EvalError::Unimplemented(format!("can't handle type: {:?}", ty))),
- }
- }
-
- fn get_field_offset(&self, ty: Ty<'tcx>, field_index: usize) -> EvalResult<Size> {
- let layout = self.type_layout(ty);
-
- use rustc::ty::layout::Layout::*;
- match *layout {
- Univariant { .. } => {
- assert_eq!(field_index, 0);
- Ok(Size::from_bytes(0))
- }
- FatPointer { .. } => {
- let bytes = layout::FAT_PTR_ADDR * self.memory.pointer_size;
- Ok(Size::from_bytes(bytes as u64))
- }
- _ => Err(EvalError::Unimplemented(format!("can't handle type: {:?}, with layout: {:?}", ty, layout))),
- }
- }
-
- fn eval_operand(&mut self, op: &mir::Operand<'tcx>) -> EvalResult<Pointer> {
- use rustc::mir::repr::Operand::*;
- match *op {
- Consume(ref lvalue) => Ok(self.eval_lvalue(lvalue)?.to_ptr()),
- Constant(mir::Constant { ref literal, .. }) => {
- use rustc::mir::repr::Literal::*;
- match *literal {
- Value { ref value } => Ok(self.const_to_ptr(value)?),
- Item { .. } => Err(EvalError::Unimplemented(format!("function pointers are unimplemented"))),
- Promoted { index } => {
- // TODO(solson): Mark constants and statics as read-only and cache their
- // values.
- let current_mir = self.mir();
- let mir = ¤t_mir.promoted[index];
- self.gecx.call(mir).map(Option::unwrap)
- }
- }
- }
- }
- }
-
- fn eval_lvalue(&mut self, lvalue: &mir::Lvalue<'tcx>) -> EvalResult<Lvalue> {
- use rustc::mir::repr::Lvalue::*;
- let ptr = match *lvalue {
- ReturnPointer => self.frame().return_ptr
- .expect("ReturnPointer used in a function with no return value"),
- Arg(i) => self.frame().locals[i as usize],
- Var(i) => self.frame().locals[self.frame().var_offset + i as usize],
- Temp(i) => self.frame().locals[self.frame().temp_offset + i as usize],
-
- Static(def_id) => {
- // TODO(solson): Mark constants and statics as read-only and cache their values.
- let mir = self.load_mir(def_id);
- self.gecx.call(&mir)?.unwrap()
- }
-
- Projection(ref proj) => {
- let base = self.eval_lvalue(&proj.base)?;
- let base_ty = self.lvalue_ty(&proj.base);
- let base_layout = self.type_layout(base_ty);
-
- use rustc::mir::repr::ProjectionElem::*;
- match proj.elem {
- Field(field, _) => {
- use rustc::ty::layout::Layout::*;
- let variant = match *base_layout {
- Univariant { ref variant, .. } => variant,
- General { ref variants, .. } => {
- if let LvalueExtra::DowncastVariant(variant_idx) = base.extra {
- &variants[variant_idx]
- } else {
- panic!("field access on enum had no variant index");
- }
- }
- RawNullablePointer { .. } => {
- assert_eq!(field.index(), 0);
- return Ok(base);
- }
- StructWrappedNullablePointer { ref nonnull, .. } => nonnull,
- _ => panic!("field access on non-product type: {:?}", base_layout),
- };
-
- let offset = variant.field_offset(field.index()).bytes();
- base.ptr.offset(offset as isize)
- },
-
- Downcast(_, variant) => {
- use rustc::ty::layout::Layout::*;
- match *base_layout {
- General { discr, .. } => {
- return Ok(Lvalue {
- ptr: base.ptr.offset(discr.size().bytes() as isize),
- extra: LvalueExtra::DowncastVariant(variant),
- });
- }
- RawNullablePointer { .. } | StructWrappedNullablePointer { .. } => {
- return Ok(base);
- }
- _ => panic!("variant downcast on non-aggregate: {:?}", base_layout),
- }
- },
-
- Deref => {
- let pointee_ty = pointee_type(base_ty).expect("Deref of non-pointer");
- let ptr = self.memory.read_ptr(base.ptr)?;
- let extra = match pointee_ty.sty {
- ty::TySlice(_) | ty::TyStr => {
- let len_ptr = base.ptr.offset(self.memory.pointer_size as isize);
- let len = self.memory.read_usize(len_ptr)?;
- LvalueExtra::Length(len)
- }
- ty::TyTrait(_) => unimplemented!(),
- _ => LvalueExtra::None,
- };
- return Ok(Lvalue { ptr: ptr, extra: extra });
- }
-
- Index(ref operand) => {
- let elem_size = match base_ty.sty {
- ty::TyArray(elem_ty, _) |
- ty::TySlice(elem_ty) => self.type_size(elem_ty),
- _ => panic!("indexing expected an array or slice, got {:?}", base_ty),
- };
- let n_ptr = self.eval_operand(operand)?;
- let n = self.memory.read_usize(n_ptr)?;
- base.ptr.offset(n as isize * elem_size as isize)
- }
-
- ConstantIndex { .. } => unimplemented!(),
- }
- }
- };
-
- Ok(Lvalue { ptr: ptr, extra: LvalueExtra::None })
- }
-
- // TODO(solson): Try making const_to_primval instead.
- fn const_to_ptr(&mut self, const_val: &const_val::ConstVal) -> EvalResult<Pointer> {
- use rustc::middle::const_val::ConstVal::*;
- match *const_val {
- Float(_f) => unimplemented!(),
- Integral(int) => {
- // TODO(solson): Check int constant type.
- let ptr = self.memory.allocate(8);
- self.memory.write_uint(ptr, int.to_u64_unchecked(), 8)?;
- Ok(ptr)
- }
- Str(ref s) => {
- let psize = self.memory.pointer_size;
- let static_ptr = self.memory.allocate(s.len());
- let ptr = self.memory.allocate(psize * 2);
- self.memory.write_bytes(static_ptr, s.as_bytes())?;
- self.memory.write_ptr(ptr, static_ptr)?;
- self.memory.write_usize(ptr.offset(psize as isize), s.len() as u64)?;
- Ok(ptr)
- }
- ByteStr(ref bs) => {
- let psize = self.memory.pointer_size;
- let static_ptr = self.memory.allocate(bs.len());
- let ptr = self.memory.allocate(psize);
- self.memory.write_bytes(static_ptr, bs)?;
- self.memory.write_ptr(ptr, static_ptr)?;
- Ok(ptr)
- }
- Bool(b) => {
- let ptr = self.memory.allocate(1);
- self.memory.write_bool(ptr, b)?;
- Ok(ptr)
- }
- Char(_c) => unimplemented!(),
- Struct(_node_id) => unimplemented!(),
- Tuple(_node_id) => unimplemented!(),
- Function(_def_id) => unimplemented!(),
- Array(_, _) => unimplemented!(),
- Repeat(_, _) => unimplemented!(),
- Dummy => unimplemented!(),
- }
- }
-
- fn lvalue_ty(&self, lvalue: &mir::Lvalue<'tcx>) -> Ty<'tcx> {
- self.monomorphize(self.mir().lvalue_ty(self.tcx, lvalue).to_ty(self.tcx))
- }
-
- fn operand_ty(&self, operand: &mir::Operand<'tcx>) -> Ty<'tcx> {
- self.monomorphize(self.mir().operand_ty(self.tcx, operand))
- }
-
- fn monomorphize(&self, ty: Ty<'tcx>) -> Ty<'tcx> {
- let substituted = ty.subst(self.tcx, self.substs());
- self.tcx.normalize_associated_type(&substituted)
- }
-
- fn type_needs_drop(&self, ty: Ty<'tcx>) -> bool {
- self.tcx.type_needs_drop_given_env(ty, &self.tcx.empty_parameter_environment())
- }
-
- fn move_(&mut self, src: Pointer, dest: Pointer, ty: Ty<'tcx>) -> EvalResult<()> {
- let size = self.type_size(ty);
- self.memory.copy(src, dest, size)?;
- if self.type_needs_drop(ty) {
- self.memory.drop_fill(src, size)?;
- }
- Ok(())
- }
-
- fn type_is_sized(&self, ty: Ty<'tcx>) -> bool {
- ty.is_sized(self.tcx, &self.tcx.empty_parameter_environment(), DUMMY_SP)
- }
-
- fn type_size(&self, ty: Ty<'tcx>) -> usize {
- self.type_layout(ty).size(&self.tcx.data_layout).bytes() as usize
- }
-
- fn type_layout(&self, ty: Ty<'tcx>) -> &'tcx Layout {
- // TODO(solson): Is this inefficient? Needs investigation.
- let ty = self.monomorphize(ty);
-
- self.tcx.normalizing_infer_ctxt(ProjectionMode::Any).enter(|infcx| {
- // TODO(solson): Report this error properly.
- ty.layout(&infcx).unwrap()
- })
- }
-
- pub fn read_primval(&mut self, ptr: Pointer, ty: Ty<'tcx>) -> EvalResult<PrimVal> {
- use syntax::ast::{IntTy, UintTy};
- let val = match (self.memory.pointer_size, &ty.sty) {
- (_, &ty::TyBool) => PrimVal::Bool(self.memory.read_bool(ptr)?),
- (_, &ty::TyInt(IntTy::I8)) => PrimVal::I8(self.memory.read_int(ptr, 1)? as i8),
- (2, &ty::TyInt(IntTy::Is)) |
- (_, &ty::TyInt(IntTy::I16)) => PrimVal::I16(self.memory.read_int(ptr, 2)? as i16),
- (4, &ty::TyInt(IntTy::Is)) |
- (_, &ty::TyInt(IntTy::I32)) => PrimVal::I32(self.memory.read_int(ptr, 4)? as i32),
- (8, &ty::TyInt(IntTy::Is)) |
- (_, &ty::TyInt(IntTy::I64)) => PrimVal::I64(self.memory.read_int(ptr, 8)? as i64),
- (_, &ty::TyUint(UintTy::U8)) => PrimVal::U8(self.memory.read_uint(ptr, 1)? as u8),
- (2, &ty::TyUint(UintTy::Us)) |
- (_, &ty::TyUint(UintTy::U16)) => PrimVal::U16(self.memory.read_uint(ptr, 2)? as u16),
- (4, &ty::TyUint(UintTy::Us)) |
- (_, &ty::TyUint(UintTy::U32)) => PrimVal::U32(self.memory.read_uint(ptr, 4)? as u32),
- (8, &ty::TyUint(UintTy::Us)) |
- (_, &ty::TyUint(UintTy::U64)) => PrimVal::U64(self.memory.read_uint(ptr, 8)? as u64),
-
- (_, &ty::TyRef(_, ty::TypeAndMut { ty, .. })) |
- (_, &ty::TyRawPtr(ty::TypeAndMut { ty, .. })) => {
- if self.type_is_sized(ty) {
- match self.memory.read_ptr(ptr) {
- Ok(p) => PrimVal::AbstractPtr(p),
- Err(EvalError::ReadBytesAsPointer) => {
- PrimVal::IntegerPtr(self.memory.read_usize(ptr)?)
- }
- Err(e) => return Err(e),
- }
- } else {
- return Err(EvalError::Unimplemented(format!("unimplemented: primitive read of fat pointer type: {:?}", ty)));
- }
- }
-
- _ => panic!("primitive read of non-primitive type: {:?}", ty),
- };
- Ok(val)
- }
-
- fn frame(&self) -> &Frame<'mir, 'tcx> {
- self.stack.last().expect("no call frames exist")
- }
-
- fn frame_mut(&mut self) -> &mut Frame<'mir, 'tcx> {
- self.stack.last_mut().expect("no call frames exist")
- }
-
- fn mir(&self) -> CachedMir<'mir, 'tcx> {
- self.frame().mir.clone()
- }
-
- fn substs(&self) -> &'tcx Substs<'tcx> {
- self.substs_stack.last().cloned().unwrap_or_else(|| self.tcx.mk_substs(Substs::empty()))
- }
-
- fn load_mir(&self, def_id: DefId) -> CachedMir<'mir, 'tcx> {
- match self.tcx.map.as_local_node_id(def_id) {
- Some(node_id) => CachedMir::Ref(self.mir_map.map.get(&node_id).unwrap()),
- None => {
- let mut mir_cache = self.mir_cache.borrow_mut();
- if let Some(mir) = mir_cache.get(&def_id) {
- return CachedMir::Owned(mir.clone());
- }
-
- let cs = &self.tcx.sess.cstore;
- let mir = cs.maybe_get_item_mir(self.tcx, def_id).unwrap_or_else(|| {
- panic!("no mir for {:?}", def_id);
- });
- let cached = Rc::new(mir);
- mir_cache.insert(def_id, cached.clone());
- CachedMir::Owned(cached)
- }
- }
- }
-
- fn fulfill_obligation(&self, trait_ref: ty::PolyTraitRef<'tcx>) -> traits::Vtable<'tcx, ()> {
- // Do the initial selection for the obligation. This yields the shallow result we are
- // looking for -- that is, what specific impl.
- self.tcx.normalizing_infer_ctxt(ProjectionMode::Any).enter(|infcx| {
- let mut selcx = traits::SelectionContext::new(&infcx);
-
- let obligation = traits::Obligation::new(
- traits::ObligationCause::misc(DUMMY_SP, ast::DUMMY_NODE_ID),
- trait_ref.to_poly_trait_predicate(),
- );
- let selection = selcx.select(&obligation).unwrap().unwrap();
-
- // Currently, we use a fulfillment context to completely resolve all nested obligations.
- // This is because they can inform the inference of the impl's type parameters.
- let mut fulfill_cx = traits::FulfillmentContext::new();
- let vtable = selection.map(|predicate| {
- fulfill_cx.register_predicate_obligation(&infcx, predicate);
- });
- infcx.drain_fulfillment_cx_or_panic(DUMMY_SP, &mut fulfill_cx, &vtable)
- })
- }
-
- /// Trait method, which has to be resolved to an impl method.
- pub fn trait_method(
- &self,
- def_id: DefId,
- substs: &'tcx Substs<'tcx>
- ) -> (DefId, &'tcx Substs<'tcx>) {
- let method_item = self.tcx.impl_or_trait_item(def_id);
- let trait_id = method_item.container().id();
- let trait_ref = ty::Binder(substs.to_trait_ref(self.tcx, trait_id));
- match self.fulfill_obligation(trait_ref) {
- traits::VtableImpl(vtable_impl) => {
- let impl_did = vtable_impl.impl_def_id;
- let mname = self.tcx.item_name(def_id);
- // Create a concatenated set of substitutions which includes those from the impl
- // and those from the method:
- let impl_substs = vtable_impl.substs.with_method_from(substs);
- let substs = self.tcx.mk_substs(impl_substs);
- let mth = get_impl_method(self.tcx, impl_did, substs, mname);
-
- (mth.method.def_id, mth.substs)
- }
-
- traits::VtableClosure(vtable_closure) =>
- (vtable_closure.closure_def_id, vtable_closure.substs.func_substs),
-
- traits::VtableFnPointer(_fn_ty) => {
- let _trait_closure_kind = self.tcx.lang_items.fn_trait_kind(trait_id).unwrap();
- unimplemented!()
- // let llfn = trans_fn_pointer_shim(ccx, trait_closure_kind, fn_ty);
-
- // let method_ty = def_ty(tcx, def_id, substs);
- // let fn_ptr_ty = match method_ty.sty {
- // ty::TyFnDef(_, _, fty) => tcx.mk_ty(ty::TyFnPtr(fty)),
- // _ => unreachable!("expected fn item type, found {}",
- // method_ty)
- // };
- // Callee::ptr(immediate_rvalue(llfn, fn_ptr_ty))
- }
-
- traits::VtableObject(ref _data) => {
- unimplemented!()
- // Callee {
- // data: Virtual(traits::get_vtable_index_of_object_method(
- // tcx, data, def_id)),
- // ty: def_ty(tcx, def_id, substs)
- // }
- }
- vtable => unreachable!("resolved vtable bad vtable {:?} in trans", vtable),
- }
- }
-}
-
-fn pointee_type(ptr_ty: ty::Ty) -> Option<ty::Ty> {
- match ptr_ty.sty {
- ty::TyRef(_, ty::TypeAndMut { ty, .. }) |
- ty::TyRawPtr(ty::TypeAndMut { ty, .. }) |
- ty::TyBox(ty) => {
- Some(ty)
- }
- _ => None,
- }
-}
-
-impl Lvalue {
- fn to_ptr(self) -> Pointer {
- assert_eq!(self.extra, LvalueExtra::None);
- self.ptr
- }
-}
-
-impl<'mir, 'tcx: 'mir> Deref for CachedMir<'mir, 'tcx> {
- type Target = mir::Mir<'tcx>;
- fn deref(&self) -> &mir::Mir<'tcx> {
- match *self {
- CachedMir::Ref(r) => r,
- CachedMir::Owned(ref rc) => rc,
- }
- }
-}
-
-#[derive(Debug)]
-pub struct ImplMethod<'tcx> {
- pub method: Rc<ty::Method<'tcx>>,
- pub substs: &'tcx Substs<'tcx>,
- pub is_provided: bool,
-}
-
-/// Locates the applicable definition of a method, given its name.
-pub fn get_impl_method<'a, 'tcx>(
- tcx: TyCtxt<'a, 'tcx, 'tcx>,
- impl_def_id: DefId,
- substs: &'tcx Substs<'tcx>,
- name: ast::Name,
-) -> ImplMethod<'tcx> {
- assert!(!substs.types.needs_infer());
-
- let trait_def_id = tcx.trait_id_of_impl(impl_def_id).unwrap();
- let trait_def = tcx.lookup_trait_def(trait_def_id);
-
- match trait_def.ancestors(impl_def_id).fn_defs(tcx, name).next() {
- Some(node_item) => {
- let substs = tcx.normalizing_infer_ctxt(ProjectionMode::Any).enter(|infcx| {
- let substs = traits::translate_substs(&infcx, impl_def_id,
- substs, node_item.node);
- tcx.lift(&substs).unwrap_or_else(|| {
- bug!("trans::meth::get_impl_method: translate_substs \
- returned {:?} which contains inference types/regions",
- substs);
- })
- });
- ImplMethod {
- method: node_item.item,
- substs: substs,
- is_provided: node_item.node.is_from_trait(),
- }
- }
- None => {
- bug!("method {:?} not found in {:?}", name, impl_def_id)
- }
- }
-}
-
-pub fn interpret_start_points<'a, 'tcx>(
- tcx: TyCtxt<'a, 'tcx, 'tcx>,
- mir_map: &MirMap<'tcx>,
-) {
- let initial_indentation = ::log_settings::settings().indentation;
- for (&id, mir) in &mir_map.map {
- for attr in tcx.map.attrs(id) {
- use syntax::attr::AttrMetaMethods;
- if attr.check_name("miri_run") {
- let item = tcx.map.expect_item(id);
-
- ::log_settings::settings().indentation = initial_indentation;
-
- debug!("Interpreting: {}", item.name);
-
- let mut gecx = GlobalEvalContext::new(tcx, mir_map);
- match gecx.call(mir) {
- Ok(Some(return_ptr)) => if log_enabled!(::log::LogLevel::Debug) {
- gecx.memory.dump(return_ptr.alloc_id);
- },
- Ok(None) => warn!("diverging function returned"),
- Err(_e) => {
- // TODO(solson): Detect whether the error was already reported or not.
- // tcx.sess.err(&e.to_string());
- }
- }
- }
- }
- }
-}
-
-// TODO(solson): Upstream these methods into rustc::ty::layout.
-
-trait IntegerExt {
- fn size(self) -> Size;
-}
-
-impl IntegerExt for layout::Integer {
- fn size(self) -> Size {
- use rustc::ty::layout::Integer::*;
- match self {
- I1 | I8 => Size::from_bits(8),
- I16 => Size::from_bits(16),
- I32 => Size::from_bits(32),
- I64 => Size::from_bits(64),
- }
- }
-}
-
-trait StructExt {
- fn field_offset(&self, index: usize) -> Size;
-}
-
-impl StructExt for layout::Struct {
- fn field_offset(&self, index: usize) -> Size {
- if index == 0 {
- Size::from_bytes(0)
- } else {
- self.offset_after_field[index - 1]
- }
- }
-}
--- /dev/null
+use super::{
+ FnEvalContext,
+ CachedMir,
+ TerminatorTarget,
+};
+use error::EvalResult;
+use rustc::mir::repr as mir;
+
+pub enum Event<'a, 'tcx: 'a> {
+ Assignment(&'a mir::Statement<'tcx>),
+ Terminator(&'a mir::Terminator<'tcx>),
+ Done,
+}
+
+pub struct Stepper<'fncx, 'a: 'fncx, 'b: 'a + 'mir, 'mir: 'fncx, 'tcx: 'b>{
+ fncx: &'fncx mut FnEvalContext<'a, 'b, 'mir, 'tcx>,
+ block: mir::BasicBlock,
+ stmt: usize,
+ mir: CachedMir<'mir, 'tcx>,
+ process: fn (&mut Stepper<'fncx, 'a, 'b, 'mir, 'tcx>) -> EvalResult<()>,
+}
+
+impl<'fncx, 'a, 'b: 'a + 'mir, 'mir, 'tcx: 'b> Stepper<'fncx, 'a, 'b, 'mir, 'tcx> {
+ pub(super) fn new(fncx: &'fncx mut FnEvalContext<'a, 'b, 'mir, 'tcx>) -> Self {
+ Stepper {
+ block: fncx.frame().next_block,
+ mir: fncx.mir(),
+ fncx: fncx,
+ stmt: 0,
+ process: Self::dummy,
+ }
+ }
+ fn dummy(&mut self) -> EvalResult<()> { Ok(()) }
+ fn statement(&mut self) -> EvalResult<()> {
+ let block_data = self.mir.basic_block_data(self.block);
+ let stmt = &block_data.statements[self.stmt];
+ let mir::StatementKind::Assign(ref lvalue, ref rvalue) = stmt.kind;
+ let result = self.fncx.eval_assignment(lvalue, rvalue);
+ self.fncx.maybe_report(stmt.span, result)?;
+ self.stmt += 1;
+ Ok(())
+ }
+ fn terminator(&mut self) -> EvalResult<()> {
+ self.stmt = 0;
+ let term = {
+ let block_data = self.mir.basic_block_data(self.block);
+ let terminator = block_data.terminator();
+ let result = self.fncx.eval_terminator(terminator);
+ self.fncx.maybe_report(terminator.span, result)?
+ };
+ match term {
+ TerminatorTarget::Block(block) => {
+ self.block = block;
+ },
+ TerminatorTarget::Return => {
+ self.fncx.pop_stack_frame();
+ self.fncx.name_stack.pop();
+ if !self.fncx.stack.is_empty() {
+ self.block = self.fncx.frame().next_block;
+ self.mir = self.fncx.mir();
+ }
+ },
+ TerminatorTarget::Call => {
+ self.block = self.fncx.frame().next_block;
+ self.mir = self.fncx.mir();
+ },
+ }
+ Ok(())
+ }
+ pub fn step<'step>(&'step mut self) -> EvalResult<Event<'step, 'tcx>> {
+ (self.process)(self)?;
+
+ if self.fncx.stack.is_empty() {
+ // fuse the iterator
+ self.process = Self::dummy;
+ return Ok(Event::Done);
+ }
+
+ let basic_block = self.mir.basic_block_data(self.block);
+
+ if let Some(stmt) = basic_block.statements.get(self.stmt) {
+ self.process = Self::statement;
+ return Ok(Event::Assignment(&stmt));
+ }
+
+ self.process = Self::terminator;
+ Ok(Event::Terminator(basic_block.terminator()))
+ }
+ pub fn block(&self) -> mir::BasicBlock {
+ self.block
+ }
+}
--- /dev/null
+use rustc::middle::const_val;
+use rustc::hir::def_id::DefId;
+use rustc::mir::mir_map::MirMap;
+use rustc::mir::repr as mir;
+use rustc::traits::{self, ProjectionMode};
+use rustc::ty::fold::TypeFoldable;
+use rustc::ty::layout::{self, Layout, Size};
+use rustc::ty::subst::{self, Subst, Substs};
+use rustc::ty::{self, Ty, TyCtxt};
+use rustc::util::nodemap::DefIdMap;
+use std::cell::RefCell;
+use std::ops::{Deref, DerefMut};
+use std::rc::Rc;
+use std::{iter, mem};
+use syntax::ast;
+use syntax::attr;
+use syntax::codemap::{self, DUMMY_SP};
+
+use error::{EvalError, EvalResult};
+use memory::{Memory, Pointer};
+use primval::{self, PrimVal};
+
+mod iterator;
+
+struct GlobalEvalContext<'a, 'tcx: 'a> {
+ /// The results of the type checker, from rustc.
+ tcx: TyCtxt<'a, 'tcx, 'tcx>,
+
+ /// A mapping from NodeIds to Mir, from rustc. Only contains MIR for crate-local items.
+ mir_map: &'a MirMap<'tcx>,
+
+ /// A local cache from DefIds to Mir for non-crate-local items.
+ mir_cache: RefCell<DefIdMap<Rc<mir::Mir<'tcx>>>>,
+
+ /// The virtual memory system.
+ memory: Memory,
+
+ /// Another stack containing the type substitutions for the current function invocation. It
+ /// exists separately from `stack` because it must contain the `Substs` for a function while
+ /// *creating* the `Frame` for that same function.
+ substs_stack: Vec<&'tcx Substs<'tcx>>,
+
+ // TODO(solson): Merge with `substs_stack`. Also try restructuring `Frame` to accomodate.
+ /// A stack of the things necessary to print good strack traces:
+ /// * Function DefIds and Substs to print proper substituted function names.
+ /// * Spans pointing to specific function calls in the source.
+ name_stack: Vec<(DefId, &'tcx Substs<'tcx>, codemap::Span)>,
+}
+
+struct FnEvalContext<'a, 'b: 'a + 'mir, 'mir, 'tcx: 'b> {
+ gecx: &'a mut GlobalEvalContext<'b, 'tcx>,
+
+ /// The virtual call stack.
+ stack: Vec<Frame<'mir, 'tcx>>,
+}
+
+impl<'a, 'b, 'mir, 'tcx> Deref for FnEvalContext<'a, 'b, 'mir, 'tcx> {
+ type Target = GlobalEvalContext<'b, 'tcx>;
+ fn deref(&self) -> &Self::Target {
+ self.gecx
+ }
+}
+
+impl<'a, 'b, 'mir, 'tcx> DerefMut for FnEvalContext<'a, 'b, 'mir, 'tcx> {
+ fn deref_mut(&mut self) -> &mut Self::Target {
+ self.gecx
+ }
+}
+
+/// A stack frame.
+struct Frame<'a, 'tcx: 'a> {
+ /// The MIR for the function called on this frame.
+ mir: CachedMir<'a, 'tcx>,
+
+ /// The block this frame will execute when a function call returns back to this frame.
+ next_block: mir::BasicBlock,
+
+ /// A pointer for writing the return value of the current call if it's not a diverging call.
+ return_ptr: Option<Pointer>,
+
+ /// The list of locals for the current function, stored in order as
+ /// `[arguments..., variables..., temporaries...]`. The variables begin at `self.var_offset`
+ /// and the temporaries at `self.temp_offset`.
+ locals: Vec<Pointer>,
+
+ /// The offset of the first variable in `self.locals`.
+ var_offset: usize,
+
+ /// The offset of the first temporary in `self.locals`.
+ temp_offset: usize,
+}
+
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+struct Lvalue {
+ ptr: Pointer,
+ extra: LvalueExtra,
+}
+
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+enum LvalueExtra {
+ None,
+ Length(u64),
+ // TODO(solson): Vtable(memory::AllocId),
+ DowncastVariant(usize),
+}
+
+#[derive(Clone)]
+enum CachedMir<'mir, 'tcx: 'mir> {
+ Ref(&'mir mir::Mir<'tcx>),
+ Owned(Rc<mir::Mir<'tcx>>)
+}
+
+/// Represents the action to be taken in the main loop as a result of executing a terminator.
+enum TerminatorTarget {
+ /// Make a local jump to the given block.
+ Block(mir::BasicBlock),
+
+ /// Start executing from the new current frame. (For function calls.)
+ Call,
+
+ /// Stop executing the current frame and resume the previous frame.
+ Return,
+}
+
+impl<'a, 'tcx> GlobalEvalContext<'a, 'tcx> {
+ fn new(tcx: TyCtxt<'a, 'tcx, 'tcx>, mir_map: &'a MirMap<'tcx>) -> Self {
+ GlobalEvalContext {
+ tcx: tcx,
+ mir_map: mir_map,
+ mir_cache: RefCell::new(DefIdMap()),
+ memory: Memory::new(tcx.sess
+ .target
+ .uint_type
+ .bit_width()
+ .expect("Session::target::uint_type was usize")/8),
+ substs_stack: Vec::new(),
+ name_stack: Vec::new(),
+ }
+ }
+
+ fn call(&mut self, mir: &mir::Mir<'tcx>) -> EvalResult<Option<Pointer>> {
+ let mut nested_fecx = FnEvalContext::new(self);
+
+ let return_ptr = match mir.return_ty {
+ ty::FnConverging(ty) => {
+ let size = nested_fecx.type_size(ty);
+ Some(nested_fecx.memory.allocate(size))
+ }
+ ty::FnDiverging => None,
+ };
+
+ let substs = nested_fecx.substs();
+ nested_fecx.push_stack_frame(CachedMir::Ref(mir), substs, return_ptr);
+ nested_fecx.run()?;
+ Ok(return_ptr)
+ }
+}
+
+impl<'a, 'b, 'mir, 'tcx> FnEvalContext<'a, 'b, 'mir, 'tcx> {
+ fn new(gecx: &'a mut GlobalEvalContext<'b, 'tcx>) -> Self {
+ FnEvalContext {
+ gecx: gecx,
+ stack: Vec::new(),
+ }
+ }
+
+ fn maybe_report<T>(&self, span: codemap::Span, r: EvalResult<T>) -> EvalResult<T> {
+ if let Err(ref e) = r {
+ let mut err = self.tcx.sess.struct_span_err(span, &e.to_string());
+ for &(def_id, substs, span) in self.name_stack.iter().rev() {
+ // FIXME(solson): Find a way to do this without this Display impl hack.
+ use rustc::util::ppaux;
+ use std::fmt;
+ struct Instance<'tcx>(DefId, &'tcx Substs<'tcx>);
+ impl<'tcx> fmt::Display for Instance<'tcx> {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ ppaux::parameterized(f, self.1, self.0, ppaux::Ns::Value, &[],
+ |tcx| tcx.lookup_item_type(self.0).generics)
+ }
+ }
+ err.span_note(span, &format!("inside call to {}", Instance(def_id, substs)));
+ }
+ err.emit();
+ }
+ r
+ }
+
+ fn run(&mut self) -> EvalResult<()> {
+ let mut stepper = iterator::Stepper::new(self);
+ 'outer: loop {
+ use self::iterator::Event::*;
+ trace!("// {:?}", stepper.block());
+
+ loop {
+ match stepper.step()? {
+ Assignment(statement) => trace!("{:?}", statement),
+ Terminator(terminator) => {
+ trace!("{:?}", terminator.kind);
+ continue 'outer;
+ },
+ Done => return Ok(()),
+ }
+ }
+ }
+ }
+
+ fn push_stack_frame(&mut self, mir: CachedMir<'mir, 'tcx>, substs: &'tcx Substs<'tcx>,
+ return_ptr: Option<Pointer>)
+ {
+ self.substs_stack.push(substs);
+
+ let arg_tys = mir.arg_decls.iter().map(|a| a.ty);
+ let var_tys = mir.var_decls.iter().map(|v| v.ty);
+ let temp_tys = mir.temp_decls.iter().map(|t| t.ty);
+
+ let locals: Vec<Pointer> = arg_tys.chain(var_tys).chain(temp_tys).map(|ty| {
+ let size = self.type_size(ty);
+ self.memory.allocate(size)
+ }).collect();
+
+ let num_args = mir.arg_decls.len();
+ let num_vars = mir.var_decls.len();
+
+ ::log_settings::settings().indentation += 1;
+
+ self.stack.push(Frame {
+ mir: mir.clone(),
+ next_block: mir::START_BLOCK,
+ return_ptr: return_ptr,
+ locals: locals,
+ var_offset: num_args,
+ temp_offset: num_args + num_vars,
+ });
+ }
+
+ fn pop_stack_frame(&mut self) {
+ ::log_settings::settings().indentation -= 1;
+ let _frame = self.stack.pop().expect("tried to pop a stack frame, but there were none");
+ // TODO(solson): Deallocate local variables.
+ self.substs_stack.pop();
+ }
+
+ fn eval_terminator(&mut self, terminator: &mir::Terminator<'tcx>)
+ -> EvalResult<TerminatorTarget> {
+ use rustc::mir::repr::TerminatorKind::*;
+ let target = match terminator.kind {
+ Return => TerminatorTarget::Return,
+
+ Goto { target } => TerminatorTarget::Block(target),
+
+ If { ref cond, targets: (then_target, else_target) } => {
+ let cond_ptr = self.eval_operand(cond)?;
+ let cond_val = self.memory.read_bool(cond_ptr)?;
+ TerminatorTarget::Block(if cond_val { then_target } else { else_target })
+ }
+
+ SwitchInt { ref discr, ref values, ref targets, .. } => {
+ let discr_ptr = self.eval_lvalue(discr)?.to_ptr();
+ let discr_size = self
+ .type_layout(self.lvalue_ty(discr))
+ .size(&self.tcx.data_layout)
+ .bytes() as usize;
+ let discr_val = self.memory.read_uint(discr_ptr, discr_size)?;
+
+ // Branch to the `otherwise` case by default, if no match is found.
+ let mut target_block = targets[targets.len() - 1];
+
+ for (index, val_const) in values.iter().enumerate() {
+ let ptr = self.const_to_ptr(val_const)?;
+ let val = self.memory.read_uint(ptr, discr_size)?;
+ if discr_val == val {
+ target_block = targets[index];
+ break;
+ }
+ }
+
+ TerminatorTarget::Block(target_block)
+ }
+
+ Switch { ref discr, ref targets, adt_def } => {
+ let adt_ptr = self.eval_lvalue(discr)?.to_ptr();
+ let adt_ty = self.lvalue_ty(discr);
+ let discr_val = self.read_discriminant_value(adt_ptr, adt_ty)?;
+ let matching = adt_def.variants.iter()
+ .position(|v| discr_val == v.disr_val.to_u64_unchecked());
+
+ match matching {
+ Some(i) => TerminatorTarget::Block(targets[i]),
+ None => return Err(EvalError::InvalidDiscriminant),
+ }
+ }
+
+ Call { ref func, ref args, ref destination, .. } => {
+ let mut return_ptr = None;
+ if let Some((ref lv, target)) = *destination {
+ self.frame_mut().next_block = target;
+ return_ptr = Some(self.eval_lvalue(lv)?.to_ptr());
+ }
+
+ let func_ty = self.operand_ty(func);
+ match func_ty.sty {
+ ty::TyFnDef(def_id, substs, fn_ty) => {
+ use syntax::abi::Abi;
+ match fn_ty.abi {
+ Abi::RustIntrinsic => {
+ let name = self.tcx.item_name(def_id).as_str();
+ match fn_ty.sig.0.output {
+ ty::FnConverging(ty) => {
+ let size = self.type_size(ty);
+ let ret = return_ptr.unwrap();
+ self.call_intrinsic(&name, substs, args, ret, size)?
+ }
+ ty::FnDiverging => unimplemented!(),
+ }
+ }
+
+ Abi::C => {
+ match fn_ty.sig.0.output {
+ ty::FnConverging(ty) => {
+ let size = self.type_size(ty);
+ self.call_c_abi(def_id, args, return_ptr.unwrap(), size)?
+ }
+ ty::FnDiverging => unimplemented!(),
+ }
+ }
+
+ Abi::Rust | Abi::RustCall => {
+ // TODO(solson): Adjust the first argument when calling a Fn or
+ // FnMut closure via FnOnce::call_once.
+
+ // Only trait methods can have a Self parameter.
+ let (resolved_def_id, resolved_substs) = if substs.self_ty().is_some() {
+ self.trait_method(def_id, substs)
+ } else {
+ (def_id, substs)
+ };
+
+ let mut arg_srcs = Vec::new();
+ for arg in args {
+ let src = self.eval_operand(arg)?;
+ let src_ty = self.operand_ty(arg);
+ arg_srcs.push((src, src_ty));
+ }
+
+ if fn_ty.abi == Abi::RustCall && !args.is_empty() {
+ arg_srcs.pop();
+ let last_arg = args.last().unwrap();
+ let last = self.eval_operand(last_arg)?;
+ let last_ty = self.operand_ty(last_arg);
+ let last_layout = self.type_layout(last_ty);
+ match (&last_ty.sty, last_layout) {
+ (&ty::TyTuple(fields),
+ &Layout::Univariant { ref variant, .. }) => {
+ let offsets = iter::once(0)
+ .chain(variant.offset_after_field.iter()
+ .map(|s| s.bytes()));
+ for (offset, ty) in offsets.zip(fields) {
+ let src = last.offset(offset as isize);
+ arg_srcs.push((src, ty));
+ }
+ }
+ ty => panic!("expected tuple as last argument in function with 'rust-call' ABI, got {:?}", ty),
+ }
+ }
+
+ let mir = self.load_mir(resolved_def_id);
+ self.name_stack.push((def_id, substs, terminator.span));
+ self.push_stack_frame(mir, resolved_substs, return_ptr);
+
+ for (i, (src, src_ty)) in arg_srcs.into_iter().enumerate() {
+ let dest = self.frame().locals[i];
+ self.move_(src, dest, src_ty)?;
+ }
+
+ TerminatorTarget::Call
+ }
+
+ abi => return Err(EvalError::Unimplemented(format!("can't handle function with {:?} ABI", abi))),
+ }
+ }
+
+ _ => return Err(EvalError::Unimplemented(format!("can't handle callee of type {:?}", func_ty))),
+ }
+ }
+
+ Drop { ref value, target, .. } => {
+ let ptr = self.eval_lvalue(value)?.to_ptr();
+ let ty = self.lvalue_ty(value);
+ self.drop(ptr, ty)?;
+ TerminatorTarget::Block(target)
+ }
+
+ Resume => unimplemented!(),
+ };
+
+ Ok(target)
+ }
+
+ fn drop(&mut self, ptr: Pointer, ty: Ty<'tcx>) -> EvalResult<()> {
+ if !self.type_needs_drop(ty) {
+ debug!("no need to drop {:?}", ty);
+ return Ok(());
+ }
+ trace!("-need to drop {:?}", ty);
+
+ // TODO(solson): Call user-defined Drop::drop impls.
+
+ match ty.sty {
+ ty::TyBox(contents_ty) => {
+ match self.memory.read_ptr(ptr) {
+ Ok(contents_ptr) => {
+ self.drop(contents_ptr, contents_ty)?;
+ trace!("-deallocating box");
+ self.memory.deallocate(contents_ptr)?;
+ }
+ Err(EvalError::ReadBytesAsPointer) => {
+ let size = self.memory.pointer_size;
+ let possible_drop_fill = self.memory.read_bytes(ptr, size)?;
+ if possible_drop_fill.iter().all(|&b| b == mem::POST_DROP_U8) {
+ return Ok(());
+ } else {
+ return Err(EvalError::ReadBytesAsPointer);
+ }
+ }
+ Err(e) => return Err(e),
+ }
+ }
+
+ // TODO(solson): Implement drop for other relevant types (e.g. aggregates).
+ _ => {}
+ }
+
+ // Filling drop.
+ // FIXME(solson): Trait objects (with no static size) probably get filled, too.
+ let size = self.type_size(ty);
+ self.memory.drop_fill(ptr, size)?;
+
+ Ok(())
+ }
+
+ fn read_discriminant_value(&self, adt_ptr: Pointer, adt_ty: Ty<'tcx>) -> EvalResult<u64> {
+ use rustc::ty::layout::Layout::*;
+ let adt_layout = self.type_layout(adt_ty);
+
+ let discr_val = match *adt_layout {
+ General { discr, .. } | CEnum { discr, .. } => {
+ let discr_size = discr.size().bytes();
+ self.memory.read_uint(adt_ptr, discr_size as usize)?
+ }
+
+ RawNullablePointer { nndiscr, .. } => {
+ self.read_nonnull_discriminant_value(adt_ptr, nndiscr)?
+ }
+
+ StructWrappedNullablePointer { nndiscr, ref discrfield, .. } => {
+ let offset = self.nonnull_offset(adt_ty, nndiscr, discrfield)?;
+ let nonnull = adt_ptr.offset(offset.bytes() as isize);
+ self.read_nonnull_discriminant_value(nonnull, nndiscr)?
+ }
+
+ // The discriminant_value intrinsic returns 0 for non-sum types.
+ Array { .. } | FatPointer { .. } | Scalar { .. } | Univariant { .. } |
+ Vector { .. } => 0,
+ };
+
+ Ok(discr_val)
+ }
+
+ fn read_nonnull_discriminant_value(&self, ptr: Pointer, nndiscr: u64) -> EvalResult<u64> {
+ let not_null = match self.memory.read_usize(ptr) {
+ Ok(0) => false,
+ Ok(_) | Err(EvalError::ReadPointerAsBytes) => true,
+ Err(e) => return Err(e),
+ };
+ assert!(nndiscr == 0 || nndiscr == 1);
+ Ok(if not_null { nndiscr } else { 1 - nndiscr })
+ }
+
+ fn call_intrinsic(
+ &mut self,
+ name: &str,
+ substs: &'tcx Substs<'tcx>,
+ args: &[mir::Operand<'tcx>],
+ dest: Pointer,
+ dest_size: usize
+ ) -> EvalResult<TerminatorTarget> {
+ let args_res: EvalResult<Vec<Pointer>> = args.iter()
+ .map(|arg| self.eval_operand(arg))
+ .collect();
+ let args = args_res?;
+
+ match name {
+ // FIXME(solson): Handle different integer types correctly.
+ "add_with_overflow" => {
+ let ty = *substs.types.get(subst::FnSpace, 0);
+ let size = self.type_size(ty);
+ let left = self.memory.read_int(args[0], size)?;
+ let right = self.memory.read_int(args[1], size)?;
+ let (n, overflowed) = unsafe {
+ ::std::intrinsics::add_with_overflow::<i64>(left, right)
+ };
+ self.memory.write_int(dest, n, size)?;
+ self.memory.write_bool(dest.offset(size as isize), overflowed)?;
+ }
+
+ "assume" => {}
+
+ "copy_nonoverlapping" => {
+ let elem_ty = *substs.types.get(subst::FnSpace, 0);
+ let elem_size = self.type_size(elem_ty);
+ let src = self.memory.read_ptr(args[0])?;
+ let dest = self.memory.read_ptr(args[1])?;
+ let count = self.memory.read_isize(args[2])?;
+ self.memory.copy(src, dest, count as usize * elem_size)?;
+ }
+
+ "discriminant_value" => {
+ let ty = *substs.types.get(subst::FnSpace, 0);
+ let adt_ptr = self.memory.read_ptr(args[0])?;
+ let discr_val = self.read_discriminant_value(adt_ptr, ty)?;
+ self.memory.write_uint(dest, discr_val, dest_size)?;
+ }
+
+ "forget" => {
+ let arg_ty = *substs.types.get(subst::FnSpace, 0);
+ let arg_size = self.type_size(arg_ty);
+ self.memory.drop_fill(args[0], arg_size)?;
+ }
+
+ "init" => self.memory.write_repeat(dest, 0, dest_size)?,
+
+ "min_align_of" => {
+ self.memory.write_int(dest, 1, dest_size)?;
+ }
+
+ "move_val_init" => {
+ let ty = *substs.types.get(subst::FnSpace, 0);
+ let ptr = self.memory.read_ptr(args[0])?;
+ self.move_(args[1], ptr, ty)?;
+ }
+
+ // FIXME(solson): Handle different integer types correctly.
+ "mul_with_overflow" => {
+ let ty = *substs.types.get(subst::FnSpace, 0);
+ let size = self.type_size(ty);
+ let left = self.memory.read_int(args[0], size)?;
+ let right = self.memory.read_int(args[1], size)?;
+ let (n, overflowed) = unsafe {
+ ::std::intrinsics::mul_with_overflow::<i64>(left, right)
+ };
+ self.memory.write_int(dest, n, size)?;
+ self.memory.write_bool(dest.offset(size as isize), overflowed)?;
+ }
+
+ "offset" => {
+ let pointee_ty = *substs.types.get(subst::FnSpace, 0);
+ let pointee_size = self.type_size(pointee_ty) as isize;
+ let ptr_arg = args[0];
+ let offset = self.memory.read_isize(args[1])?;
+
+ match self.memory.read_ptr(ptr_arg) {
+ Ok(ptr) => {
+ let result_ptr = ptr.offset(offset as isize * pointee_size);
+ self.memory.write_ptr(dest, result_ptr)?;
+ }
+ Err(EvalError::ReadBytesAsPointer) => {
+ let addr = self.memory.read_isize(ptr_arg)?;
+ let result_addr = addr + offset * pointee_size as i64;
+ self.memory.write_isize(dest, result_addr)?;
+ }
+ Err(e) => return Err(e),
+ }
+ }
+
+ // FIXME(solson): Handle different integer types correctly. Use primvals?
+ "overflowing_sub" => {
+ let ty = *substs.types.get(subst::FnSpace, 0);
+ let size = self.type_size(ty);
+ let left = self.memory.read_int(args[0], size)?;
+ let right = self.memory.read_int(args[1], size)?;
+ let n = left.wrapping_sub(right);
+ self.memory.write_int(dest, n, size)?;
+ }
+
+ "size_of" => {
+ let ty = *substs.types.get(subst::FnSpace, 0);
+ let size = self.type_size(ty) as u64;
+ self.memory.write_uint(dest, size, dest_size)?;
+ }
+
+ "size_of_val" => {
+ let ty = *substs.types.get(subst::FnSpace, 0);
+ if self.type_is_sized(ty) {
+ let size = self.type_size(ty) as u64;
+ self.memory.write_uint(dest, size, dest_size)?;
+ } else {
+ match ty.sty {
+ ty::TySlice(_) | ty::TyStr => {
+ let elem_ty = ty.sequence_element_type(self.tcx);
+ let elem_size = self.type_size(elem_ty) as u64;
+ let ptr_size = self.memory.pointer_size as isize;
+ let n = self.memory.read_usize(args[0].offset(ptr_size))?;
+ self.memory.write_uint(dest, n * elem_size, dest_size)?;
+ }
+
+ _ => return Err(EvalError::Unimplemented(format!("unimplemented: size_of_val::<{:?}>", ty))),
+ }
+ }
+ }
+
+ "transmute" => {
+ let ty = *substs.types.get(subst::FnSpace, 0);
+ self.move_(args[0], dest, ty)?;
+ }
+ "uninit" => self.memory.mark_definedness(dest, dest_size, false)?,
+
+ name => return Err(EvalError::Unimplemented(format!("unimplemented intrinsic: {}", name))),
+ }
+
+ // Since we pushed no stack frame, the main loop will act
+ // as if the call just completed and it's returning to the
+ // current frame.
+ Ok(TerminatorTarget::Call)
+ }
+
+ fn call_c_abi(
+ &mut self,
+ def_id: DefId,
+ args: &[mir::Operand<'tcx>],
+ dest: Pointer,
+ dest_size: usize,
+ ) -> EvalResult<TerminatorTarget> {
+ let name = self.tcx.item_name(def_id);
+ let attrs = self.tcx.get_attrs(def_id);
+ let link_name = match attr::first_attr_value_str_by_name(&attrs, "link_name") {
+ Some(ln) => ln.clone(),
+ None => name.as_str(),
+ };
+
+ let args_res: EvalResult<Vec<Pointer>> = args.iter()
+ .map(|arg| self.eval_operand(arg))
+ .collect();
+ let args = args_res?;
+
+ match &link_name[..] {
+ "__rust_allocate" => {
+ let size = self.memory.read_usize(args[0])?;
+ let ptr = self.memory.allocate(size as usize);
+ self.memory.write_ptr(dest, ptr)?;
+ }
+
+ "__rust_reallocate" => {
+ let ptr = self.memory.read_ptr(args[0])?;
+ let size = self.memory.read_usize(args[2])?;
+ self.memory.reallocate(ptr, size as usize)?;
+ self.memory.write_ptr(dest, ptr)?;
+ }
+
+ "memcmp" => {
+ let left = self.memory.read_ptr(args[0])?;
+ let right = self.memory.read_ptr(args[1])?;
+ let n = self.memory.read_usize(args[2])? as usize;
+
+ let result = {
+ let left_bytes = self.memory.read_bytes(left, n)?;
+ let right_bytes = self.memory.read_bytes(right, n)?;
+
+ use std::cmp::Ordering::*;
+ match left_bytes.cmp(right_bytes) {
+ Less => -1,
+ Equal => 0,
+ Greater => 1,
+ }
+ };
+
+ self.memory.write_int(dest, result, dest_size)?;
+ }
+
+ _ => return Err(EvalError::Unimplemented(format!("can't call C ABI function: {}", link_name))),
+ }
+
+ // Since we pushed no stack frame, the main loop will act
+ // as if the call just completed and it's returning to the
+ // current frame.
+ Ok(TerminatorTarget::Call)
+ }
+
+ fn assign_fields<I: IntoIterator<Item = u64>>(
+ &mut self,
+ dest: Pointer,
+ offsets: I,
+ operands: &[mir::Operand<'tcx>],
+ ) -> EvalResult<()> {
+ for (offset, operand) in offsets.into_iter().zip(operands) {
+ let src = self.eval_operand(operand)?;
+ let src_ty = self.operand_ty(operand);
+ let field_dest = dest.offset(offset as isize);
+ self.move_(src, field_dest, src_ty)?;
+ }
+ Ok(())
+ }
+
+ fn eval_assignment(&mut self, lvalue: &mir::Lvalue<'tcx>, rvalue: &mir::Rvalue<'tcx>)
+ -> EvalResult<()>
+ {
+ let dest = self.eval_lvalue(lvalue)?.to_ptr();
+ let dest_ty = self.lvalue_ty(lvalue);
+ let dest_layout = self.type_layout(dest_ty);
+
+ use rustc::mir::repr::Rvalue::*;
+ match *rvalue {
+ Use(ref operand) => {
+ let src = self.eval_operand(operand)?;
+ self.move_(src, dest, dest_ty)?;
+ }
+
+ BinaryOp(bin_op, ref left, ref right) => {
+ let left_ptr = self.eval_operand(left)?;
+ let left_ty = self.operand_ty(left);
+ let left_val = self.read_primval(left_ptr, left_ty)?;
+
+ let right_ptr = self.eval_operand(right)?;
+ let right_ty = self.operand_ty(right);
+ let right_val = self.read_primval(right_ptr, right_ty)?;
+
+ let val = primval::binary_op(bin_op, left_val, right_val)?;
+ self.memory.write_primval(dest, val)?;
+ }
+
+ UnaryOp(un_op, ref operand) => {
+ let ptr = self.eval_operand(operand)?;
+ let ty = self.operand_ty(operand);
+ let val = self.read_primval(ptr, ty)?;
+ self.memory.write_primval(dest, primval::unary_op(un_op, val)?)?;
+ }
+
+ Aggregate(ref kind, ref operands) => {
+ use rustc::ty::layout::Layout::*;
+ match *dest_layout {
+ Univariant { ref variant, .. } => {
+ let offsets = iter::once(0)
+ .chain(variant.offset_after_field.iter().map(|s| s.bytes()));
+ self.assign_fields(dest, offsets, operands)?;
+ }
+
+ Array { .. } => {
+ let elem_size = match dest_ty.sty {
+ ty::TyArray(elem_ty, _) => self.type_size(elem_ty) as u64,
+ _ => panic!("tried to assign {:?} to non-array type {:?}",
+ kind, dest_ty),
+ };
+ let offsets = (0..).map(|i| i * elem_size);
+ self.assign_fields(dest, offsets, operands)?;
+ }
+
+ General { discr, ref variants, .. } => {
+ if let mir::AggregateKind::Adt(adt_def, variant, _) = *kind {
+ let discr_val = adt_def.variants[variant].disr_val.to_u64_unchecked();
+ let discr_size = discr.size().bytes() as usize;
+ self.memory.write_uint(dest, discr_val, discr_size)?;
+
+ let offsets = variants[variant].offset_after_field.iter()
+ .map(|s| s.bytes());
+ self.assign_fields(dest, offsets, operands)?;
+ } else {
+ panic!("tried to assign {:?} to Layout::General", kind);
+ }
+ }
+
+ RawNullablePointer { nndiscr, .. } => {
+ if let mir::AggregateKind::Adt(_, variant, _) = *kind {
+ if nndiscr == variant as u64 {
+ assert_eq!(operands.len(), 1);
+ let operand = &operands[0];
+ let src = self.eval_operand(operand)?;
+ let src_ty = self.operand_ty(operand);
+ self.move_(src, dest, src_ty)?;
+ } else {
+ assert_eq!(operands.len(), 0);
+ self.memory.write_isize(dest, 0)?;
+ }
+ } else {
+ panic!("tried to assign {:?} to Layout::RawNullablePointer", kind);
+ }
+ }
+
+ StructWrappedNullablePointer { nndiscr, ref nonnull, ref discrfield } => {
+ if let mir::AggregateKind::Adt(_, variant, _) = *kind {
+ if nndiscr == variant as u64 {
+ let offsets = iter::once(0)
+ .chain(nonnull.offset_after_field.iter().map(|s| s.bytes()));
+ try!(self.assign_fields(dest, offsets, operands));
+ } else {
+ assert_eq!(operands.len(), 0);
+ let offset = self.nonnull_offset(dest_ty, nndiscr, discrfield)?;
+ let dest = dest.offset(offset.bytes() as isize);
+ try!(self.memory.write_isize(dest, 0));
+ }
+ } else {
+ panic!("tried to assign {:?} to Layout::RawNullablePointer", kind);
+ }
+ }
+
+ CEnum { discr, signed, .. } => {
+ assert_eq!(operands.len(), 0);
+ if let mir::AggregateKind::Adt(adt_def, variant, _) = *kind {
+ let val = adt_def.variants[variant].disr_val.to_u64_unchecked();
+ let size = discr.size().bytes() as usize;
+
+ if signed {
+ self.memory.write_int(dest, val as i64, size)?;
+ } else {
+ self.memory.write_uint(dest, val, size)?;
+ }
+ } else {
+ panic!("tried to assign {:?} to Layout::CEnum", kind);
+ }
+ }
+
+ _ => return Err(EvalError::Unimplemented(format!("can't handle destination layout {:?} when assigning {:?}", dest_layout, kind))),
+ }
+ }
+
+ Repeat(ref operand, _) => {
+ let (elem_size, length) = match dest_ty.sty {
+ ty::TyArray(elem_ty, n) => (self.type_size(elem_ty), n),
+ _ => panic!("tried to assign array-repeat to non-array type {:?}", dest_ty),
+ };
+
+ let src = self.eval_operand(operand)?;
+ for i in 0..length {
+ let elem_dest = dest.offset((i * elem_size) as isize);
+ self.memory.copy(src, elem_dest, elem_size)?;
+ }
+ }
+
+ Len(ref lvalue) => {
+ let src = self.eval_lvalue(lvalue)?;
+ let ty = self.lvalue_ty(lvalue);
+ let len = match ty.sty {
+ ty::TyArray(_, n) => n as u64,
+ ty::TySlice(_) => if let LvalueExtra::Length(n) = src.extra {
+ n
+ } else {
+ panic!("Rvalue::Len of a slice given non-slice pointer: {:?}", src);
+ },
+ _ => panic!("Rvalue::Len expected array or slice, got {:?}", ty),
+ };
+ self.memory.write_usize(dest, len)?;
+ }
+
+ Ref(_, _, ref lvalue) => {
+ let lv = self.eval_lvalue(lvalue)?;
+ self.memory.write_ptr(dest, lv.ptr)?;
+ match lv.extra {
+ LvalueExtra::None => {},
+ LvalueExtra::Length(len) => {
+ let len_ptr = dest.offset(self.memory.pointer_size as isize);
+ self.memory.write_usize(len_ptr, len)?;
+ }
+ LvalueExtra::DowncastVariant(..) =>
+ panic!("attempted to take a reference to an enum downcast lvalue"),
+ }
+ }
+
+ Box(ty) => {
+ let size = self.type_size(ty);
+ let ptr = self.memory.allocate(size);
+ self.memory.write_ptr(dest, ptr)?;
+ }
+
+ Cast(kind, ref operand, dest_ty) => {
+ let src = self.eval_operand(operand)?;
+ let src_ty = self.operand_ty(operand);
+
+ use rustc::mir::repr::CastKind::*;
+ match kind {
+ Unsize => {
+ self.move_(src, dest, src_ty)?;
+ let src_pointee_ty = pointee_type(src_ty).unwrap();
+ let dest_pointee_ty = pointee_type(dest_ty).unwrap();
+
+ match (&src_pointee_ty.sty, &dest_pointee_ty.sty) {
+ (&ty::TyArray(_, length), &ty::TySlice(_)) => {
+ let len_ptr = dest.offset(self.memory.pointer_size as isize);
+ self.memory.write_usize(len_ptr, length as u64)?;
+ }
+
+ _ => return Err(EvalError::Unimplemented(format!("can't handle cast: {:?}", rvalue))),
+ }
+ }
+
+ Misc => {
+ // FIXME(solson): Wrong for almost everything.
+ let size = dest_layout.size(&self.tcx.data_layout).bytes() as usize;
+ self.memory.copy(src, dest, size)?;
+ }
+
+ _ => return Err(EvalError::Unimplemented(format!("can't handle cast: {:?}", rvalue))),
+ }
+ }
+
+ Slice { .. } => unimplemented!(),
+ InlineAsm { .. } => unimplemented!(),
+ }
+
+ Ok(())
+ }
+
+ fn nonnull_offset(&self, ty: Ty<'tcx>, nndiscr: u64, discrfield: &[u32]) -> EvalResult<Size> {
+ // Skip the constant 0 at the start meant for LLVM GEP.
+ let mut path = discrfield.iter().skip(1).map(|&i| i as usize);
+
+ // Handle the field index for the outer non-null variant.
+ let inner_ty = match ty.sty {
+ ty::TyEnum(adt_def, substs) => {
+ let variant = &adt_def.variants[nndiscr as usize];
+ let index = path.next().unwrap();
+ let field = &variant.fields[index];
+ field.ty(self.tcx, substs)
+ }
+ _ => panic!(
+ "non-enum for StructWrappedNullablePointer: {}",
+ ty,
+ ),
+ };
+
+ self.field_path_offset(inner_ty, path)
+ }
+
+ fn field_path_offset<I: Iterator<Item = usize>>(&self, mut ty: Ty<'tcx>, path: I) -> EvalResult<Size> {
+ let mut offset = Size::from_bytes(0);
+
+ // Skip the initial 0 intended for LLVM GEP.
+ for field_index in path {
+ let field_offset = self.get_field_offset(ty, field_index)?;
+ ty = self.get_field_ty(ty, field_index)?;
+ offset = offset.checked_add(field_offset, &self.tcx.data_layout).unwrap();
+ }
+
+ Ok(offset)
+ }
+
+ fn get_field_ty(&self, ty: Ty<'tcx>, field_index: usize) -> EvalResult<Ty<'tcx>> {
+ match ty.sty {
+ ty::TyStruct(adt_def, substs) => {
+ Ok(adt_def.struct_variant().fields[field_index].ty(self.tcx, substs))
+ }
+
+ ty::TyRef(_, ty::TypeAndMut { ty, .. }) |
+ ty::TyRawPtr(ty::TypeAndMut { ty, .. }) |
+ ty::TyBox(ty) => {
+ assert_eq!(field_index, 0);
+ Ok(ty)
+ }
+ _ => Err(EvalError::Unimplemented(format!("can't handle type: {:?}", ty))),
+ }
+ }
+
+ fn get_field_offset(&self, ty: Ty<'tcx>, field_index: usize) -> EvalResult<Size> {
+ let layout = self.type_layout(ty);
+
+ use rustc::ty::layout::Layout::*;
+ match *layout {
+ Univariant { .. } => {
+ assert_eq!(field_index, 0);
+ Ok(Size::from_bytes(0))
+ }
+ FatPointer { .. } => {
+ let bytes = layout::FAT_PTR_ADDR * self.memory.pointer_size;
+ Ok(Size::from_bytes(bytes as u64))
+ }
+ _ => Err(EvalError::Unimplemented(format!("can't handle type: {:?}, with layout: {:?}", ty, layout))),
+ }
+ }
+
+ fn eval_operand(&mut self, op: &mir::Operand<'tcx>) -> EvalResult<Pointer> {
+ use rustc::mir::repr::Operand::*;
+ match *op {
+ Consume(ref lvalue) => Ok(self.eval_lvalue(lvalue)?.to_ptr()),
+ Constant(mir::Constant { ref literal, .. }) => {
+ use rustc::mir::repr::Literal::*;
+ match *literal {
+ Value { ref value } => Ok(self.const_to_ptr(value)?),
+ Item { .. } => Err(EvalError::Unimplemented(format!("function pointers are unimplemented"))),
+ Promoted { index } => {
+ // TODO(solson): Mark constants and statics as read-only and cache their
+ // values.
+ let current_mir = self.mir();
+ let mir = ¤t_mir.promoted[index];
+ self.gecx.call(mir).map(Option::unwrap)
+ }
+ }
+ }
+ }
+ }
+
+ fn eval_lvalue(&mut self, lvalue: &mir::Lvalue<'tcx>) -> EvalResult<Lvalue> {
+ use rustc::mir::repr::Lvalue::*;
+ let ptr = match *lvalue {
+ ReturnPointer => self.frame().return_ptr
+ .expect("ReturnPointer used in a function with no return value"),
+ Arg(i) => self.frame().locals[i as usize],
+ Var(i) => self.frame().locals[self.frame().var_offset + i as usize],
+ Temp(i) => self.frame().locals[self.frame().temp_offset + i as usize],
+
+ Static(def_id) => {
+ // TODO(solson): Mark constants and statics as read-only and cache their values.
+ let mir = self.load_mir(def_id);
+ self.gecx.call(&mir)?.unwrap()
+ }
+
+ Projection(ref proj) => {
+ let base = self.eval_lvalue(&proj.base)?;
+ let base_ty = self.lvalue_ty(&proj.base);
+ let base_layout = self.type_layout(base_ty);
+
+ use rustc::mir::repr::ProjectionElem::*;
+ match proj.elem {
+ Field(field, _) => {
+ use rustc::ty::layout::Layout::*;
+ let variant = match *base_layout {
+ Univariant { ref variant, .. } => variant,
+ General { ref variants, .. } => {
+ if let LvalueExtra::DowncastVariant(variant_idx) = base.extra {
+ &variants[variant_idx]
+ } else {
+ panic!("field access on enum had no variant index");
+ }
+ }
+ RawNullablePointer { .. } => {
+ assert_eq!(field.index(), 0);
+ return Ok(base);
+ }
+ StructWrappedNullablePointer { ref nonnull, .. } => nonnull,
+ _ => panic!("field access on non-product type: {:?}", base_layout),
+ };
+
+ let offset = variant.field_offset(field.index()).bytes();
+ base.ptr.offset(offset as isize)
+ },
+
+ Downcast(_, variant) => {
+ use rustc::ty::layout::Layout::*;
+ match *base_layout {
+ General { discr, .. } => {
+ return Ok(Lvalue {
+ ptr: base.ptr.offset(discr.size().bytes() as isize),
+ extra: LvalueExtra::DowncastVariant(variant),
+ });
+ }
+ RawNullablePointer { .. } | StructWrappedNullablePointer { .. } => {
+ return Ok(base);
+ }
+ _ => panic!("variant downcast on non-aggregate: {:?}", base_layout),
+ }
+ },
+
+ Deref => {
+ let pointee_ty = pointee_type(base_ty).expect("Deref of non-pointer");
+ let ptr = self.memory.read_ptr(base.ptr)?;
+ let extra = match pointee_ty.sty {
+ ty::TySlice(_) | ty::TyStr => {
+ let len_ptr = base.ptr.offset(self.memory.pointer_size as isize);
+ let len = self.memory.read_usize(len_ptr)?;
+ LvalueExtra::Length(len)
+ }
+ ty::TyTrait(_) => unimplemented!(),
+ _ => LvalueExtra::None,
+ };
+ return Ok(Lvalue { ptr: ptr, extra: extra });
+ }
+
+ Index(ref operand) => {
+ let elem_size = match base_ty.sty {
+ ty::TyArray(elem_ty, _) |
+ ty::TySlice(elem_ty) => self.type_size(elem_ty),
+ _ => panic!("indexing expected an array or slice, got {:?}", base_ty),
+ };
+ let n_ptr = self.eval_operand(operand)?;
+ let n = self.memory.read_usize(n_ptr)?;
+ base.ptr.offset(n as isize * elem_size as isize)
+ }
+
+ ConstantIndex { .. } => unimplemented!(),
+ }
+ }
+ };
+
+ Ok(Lvalue { ptr: ptr, extra: LvalueExtra::None })
+ }
+
+ // TODO(solson): Try making const_to_primval instead.
+ fn const_to_ptr(&mut self, const_val: &const_val::ConstVal) -> EvalResult<Pointer> {
+ use rustc::middle::const_val::ConstVal::*;
+ match *const_val {
+ Float(_f) => unimplemented!(),
+ Integral(int) => {
+ // TODO(solson): Check int constant type.
+ let ptr = self.memory.allocate(8);
+ self.memory.write_uint(ptr, int.to_u64_unchecked(), 8)?;
+ Ok(ptr)
+ }
+ Str(ref s) => {
+ let psize = self.memory.pointer_size;
+ let static_ptr = self.memory.allocate(s.len());
+ let ptr = self.memory.allocate(psize * 2);
+ self.memory.write_bytes(static_ptr, s.as_bytes())?;
+ self.memory.write_ptr(ptr, static_ptr)?;
+ self.memory.write_usize(ptr.offset(psize as isize), s.len() as u64)?;
+ Ok(ptr)
+ }
+ ByteStr(ref bs) => {
+ let psize = self.memory.pointer_size;
+ let static_ptr = self.memory.allocate(bs.len());
+ let ptr = self.memory.allocate(psize);
+ self.memory.write_bytes(static_ptr, bs)?;
+ self.memory.write_ptr(ptr, static_ptr)?;
+ Ok(ptr)
+ }
+ Bool(b) => {
+ let ptr = self.memory.allocate(1);
+ self.memory.write_bool(ptr, b)?;
+ Ok(ptr)
+ }
+ Char(_c) => unimplemented!(),
+ Struct(_node_id) => unimplemented!(),
+ Tuple(_node_id) => unimplemented!(),
+ Function(_def_id) => unimplemented!(),
+ Array(_, _) => unimplemented!(),
+ Repeat(_, _) => unimplemented!(),
+ Dummy => unimplemented!(),
+ }
+ }
+
+ fn lvalue_ty(&self, lvalue: &mir::Lvalue<'tcx>) -> Ty<'tcx> {
+ self.monomorphize(self.mir().lvalue_ty(self.tcx, lvalue).to_ty(self.tcx))
+ }
+
+ fn operand_ty(&self, operand: &mir::Operand<'tcx>) -> Ty<'tcx> {
+ self.monomorphize(self.mir().operand_ty(self.tcx, operand))
+ }
+
+ fn monomorphize(&self, ty: Ty<'tcx>) -> Ty<'tcx> {
+ let substituted = ty.subst(self.tcx, self.substs());
+ self.tcx.normalize_associated_type(&substituted)
+ }
+
+ fn type_needs_drop(&self, ty: Ty<'tcx>) -> bool {
+ self.tcx.type_needs_drop_given_env(ty, &self.tcx.empty_parameter_environment())
+ }
+
+ fn move_(&mut self, src: Pointer, dest: Pointer, ty: Ty<'tcx>) -> EvalResult<()> {
+ let size = self.type_size(ty);
+ self.memory.copy(src, dest, size)?;
+ if self.type_needs_drop(ty) {
+ self.memory.drop_fill(src, size)?;
+ }
+ Ok(())
+ }
+
+ fn type_is_sized(&self, ty: Ty<'tcx>) -> bool {
+ ty.is_sized(self.tcx, &self.tcx.empty_parameter_environment(), DUMMY_SP)
+ }
+
+ fn type_size(&self, ty: Ty<'tcx>) -> usize {
+ self.type_layout(ty).size(&self.tcx.data_layout).bytes() as usize
+ }
+
+ fn type_layout(&self, ty: Ty<'tcx>) -> &'tcx Layout {
+ // TODO(solson): Is this inefficient? Needs investigation.
+ let ty = self.monomorphize(ty);
+
+ self.tcx.normalizing_infer_ctxt(ProjectionMode::Any).enter(|infcx| {
+ // TODO(solson): Report this error properly.
+ ty.layout(&infcx).unwrap()
+ })
+ }
+
+ pub fn read_primval(&mut self, ptr: Pointer, ty: Ty<'tcx>) -> EvalResult<PrimVal> {
+ use syntax::ast::{IntTy, UintTy};
+ let val = match (self.memory.pointer_size, &ty.sty) {
+ (_, &ty::TyBool) => PrimVal::Bool(self.memory.read_bool(ptr)?),
+ (_, &ty::TyInt(IntTy::I8)) => PrimVal::I8(self.memory.read_int(ptr, 1)? as i8),
+ (2, &ty::TyInt(IntTy::Is)) |
+ (_, &ty::TyInt(IntTy::I16)) => PrimVal::I16(self.memory.read_int(ptr, 2)? as i16),
+ (4, &ty::TyInt(IntTy::Is)) |
+ (_, &ty::TyInt(IntTy::I32)) => PrimVal::I32(self.memory.read_int(ptr, 4)? as i32),
+ (8, &ty::TyInt(IntTy::Is)) |
+ (_, &ty::TyInt(IntTy::I64)) => PrimVal::I64(self.memory.read_int(ptr, 8)? as i64),
+ (_, &ty::TyUint(UintTy::U8)) => PrimVal::U8(self.memory.read_uint(ptr, 1)? as u8),
+ (2, &ty::TyUint(UintTy::Us)) |
+ (_, &ty::TyUint(UintTy::U16)) => PrimVal::U16(self.memory.read_uint(ptr, 2)? as u16),
+ (4, &ty::TyUint(UintTy::Us)) |
+ (_, &ty::TyUint(UintTy::U32)) => PrimVal::U32(self.memory.read_uint(ptr, 4)? as u32),
+ (8, &ty::TyUint(UintTy::Us)) |
+ (_, &ty::TyUint(UintTy::U64)) => PrimVal::U64(self.memory.read_uint(ptr, 8)? as u64),
+
+ (_, &ty::TyRef(_, ty::TypeAndMut { ty, .. })) |
+ (_, &ty::TyRawPtr(ty::TypeAndMut { ty, .. })) => {
+ if self.type_is_sized(ty) {
+ match self.memory.read_ptr(ptr) {
+ Ok(p) => PrimVal::AbstractPtr(p),
+ Err(EvalError::ReadBytesAsPointer) => {
+ PrimVal::IntegerPtr(self.memory.read_usize(ptr)?)
+ }
+ Err(e) => return Err(e),
+ }
+ } else {
+ return Err(EvalError::Unimplemented(format!("unimplemented: primitive read of fat pointer type: {:?}", ty)));
+ }
+ }
+
+ _ => panic!("primitive read of non-primitive type: {:?}", ty),
+ };
+ Ok(val)
+ }
+
+ fn frame(&self) -> &Frame<'mir, 'tcx> {
+ self.stack.last().expect("no call frames exist")
+ }
+
+ fn frame_mut(&mut self) -> &mut Frame<'mir, 'tcx> {
+ self.stack.last_mut().expect("no call frames exist")
+ }
+
+ fn mir(&self) -> CachedMir<'mir, 'tcx> {
+ self.frame().mir.clone()
+ }
+
+ fn substs(&self) -> &'tcx Substs<'tcx> {
+ self.substs_stack.last().cloned().unwrap_or_else(|| self.tcx.mk_substs(Substs::empty()))
+ }
+
+ fn load_mir(&self, def_id: DefId) -> CachedMir<'mir, 'tcx> {
+ match self.tcx.map.as_local_node_id(def_id) {
+ Some(node_id) => CachedMir::Ref(self.mir_map.map.get(&node_id).unwrap()),
+ None => {
+ let mut mir_cache = self.mir_cache.borrow_mut();
+ if let Some(mir) = mir_cache.get(&def_id) {
+ return CachedMir::Owned(mir.clone());
+ }
+
+ let cs = &self.tcx.sess.cstore;
+ let mir = cs.maybe_get_item_mir(self.tcx, def_id).unwrap_or_else(|| {
+ panic!("no mir for {:?}", def_id);
+ });
+ let cached = Rc::new(mir);
+ mir_cache.insert(def_id, cached.clone());
+ CachedMir::Owned(cached)
+ }
+ }
+ }
+
+ fn fulfill_obligation(&self, trait_ref: ty::PolyTraitRef<'tcx>) -> traits::Vtable<'tcx, ()> {
+ // Do the initial selection for the obligation. This yields the shallow result we are
+ // looking for -- that is, what specific impl.
+ self.tcx.normalizing_infer_ctxt(ProjectionMode::Any).enter(|infcx| {
+ let mut selcx = traits::SelectionContext::new(&infcx);
+
+ let obligation = traits::Obligation::new(
+ traits::ObligationCause::misc(DUMMY_SP, ast::DUMMY_NODE_ID),
+ trait_ref.to_poly_trait_predicate(),
+ );
+ let selection = selcx.select(&obligation).unwrap().unwrap();
+
+ // Currently, we use a fulfillment context to completely resolve all nested obligations.
+ // This is because they can inform the inference of the impl's type parameters.
+ let mut fulfill_cx = traits::FulfillmentContext::new();
+ let vtable = selection.map(|predicate| {
+ fulfill_cx.register_predicate_obligation(&infcx, predicate);
+ });
+ infcx.drain_fulfillment_cx_or_panic(DUMMY_SP, &mut fulfill_cx, &vtable)
+ })
+ }
+
+ /// Trait method, which has to be resolved to an impl method.
+ pub fn trait_method(
+ &self,
+ def_id: DefId,
+ substs: &'tcx Substs<'tcx>
+ ) -> (DefId, &'tcx Substs<'tcx>) {
+ let method_item = self.tcx.impl_or_trait_item(def_id);
+ let trait_id = method_item.container().id();
+ let trait_ref = ty::Binder(substs.to_trait_ref(self.tcx, trait_id));
+ match self.fulfill_obligation(trait_ref) {
+ traits::VtableImpl(vtable_impl) => {
+ let impl_did = vtable_impl.impl_def_id;
+ let mname = self.tcx.item_name(def_id);
+ // Create a concatenated set of substitutions which includes those from the impl
+ // and those from the method:
+ let impl_substs = vtable_impl.substs.with_method_from(substs);
+ let substs = self.tcx.mk_substs(impl_substs);
+ let mth = get_impl_method(self.tcx, impl_did, substs, mname);
+
+ (mth.method.def_id, mth.substs)
+ }
+
+ traits::VtableClosure(vtable_closure) =>
+ (vtable_closure.closure_def_id, vtable_closure.substs.func_substs),
+
+ traits::VtableFnPointer(_fn_ty) => {
+ let _trait_closure_kind = self.tcx.lang_items.fn_trait_kind(trait_id).unwrap();
+ unimplemented!()
+ // let llfn = trans_fn_pointer_shim(ccx, trait_closure_kind, fn_ty);
+
+ // let method_ty = def_ty(tcx, def_id, substs);
+ // let fn_ptr_ty = match method_ty.sty {
+ // ty::TyFnDef(_, _, fty) => tcx.mk_ty(ty::TyFnPtr(fty)),
+ // _ => unreachable!("expected fn item type, found {}",
+ // method_ty)
+ // };
+ // Callee::ptr(immediate_rvalue(llfn, fn_ptr_ty))
+ }
+
+ traits::VtableObject(ref _data) => {
+ unimplemented!()
+ // Callee {
+ // data: Virtual(traits::get_vtable_index_of_object_method(
+ // tcx, data, def_id)),
+ // ty: def_ty(tcx, def_id, substs)
+ // }
+ }
+ vtable => unreachable!("resolved vtable bad vtable {:?} in trans", vtable),
+ }
+ }
+}
+
+fn pointee_type(ptr_ty: ty::Ty) -> Option<ty::Ty> {
+ match ptr_ty.sty {
+ ty::TyRef(_, ty::TypeAndMut { ty, .. }) |
+ ty::TyRawPtr(ty::TypeAndMut { ty, .. }) |
+ ty::TyBox(ty) => {
+ Some(ty)
+ }
+ _ => None,
+ }
+}
+
+impl Lvalue {
+ fn to_ptr(self) -> Pointer {
+ assert_eq!(self.extra, LvalueExtra::None);
+ self.ptr
+ }
+}
+
+impl<'mir, 'tcx: 'mir> Deref for CachedMir<'mir, 'tcx> {
+ type Target = mir::Mir<'tcx>;
+ fn deref(&self) -> &mir::Mir<'tcx> {
+ match *self {
+ CachedMir::Ref(r) => r,
+ CachedMir::Owned(ref rc) => rc,
+ }
+ }
+}
+
+#[derive(Debug)]
+pub struct ImplMethod<'tcx> {
+ pub method: Rc<ty::Method<'tcx>>,
+ pub substs: &'tcx Substs<'tcx>,
+ pub is_provided: bool,
+}
+
+/// Locates the applicable definition of a method, given its name.
+pub fn get_impl_method<'a, 'tcx>(
+ tcx: TyCtxt<'a, 'tcx, 'tcx>,
+ impl_def_id: DefId,
+ substs: &'tcx Substs<'tcx>,
+ name: ast::Name,
+) -> ImplMethod<'tcx> {
+ assert!(!substs.types.needs_infer());
+
+ let trait_def_id = tcx.trait_id_of_impl(impl_def_id).unwrap();
+ let trait_def = tcx.lookup_trait_def(trait_def_id);
+
+ match trait_def.ancestors(impl_def_id).fn_defs(tcx, name).next() {
+ Some(node_item) => {
+ let substs = tcx.normalizing_infer_ctxt(ProjectionMode::Any).enter(|infcx| {
+ let substs = traits::translate_substs(&infcx, impl_def_id,
+ substs, node_item.node);
+ tcx.lift(&substs).unwrap_or_else(|| {
+ bug!("trans::meth::get_impl_method: translate_substs \
+ returned {:?} which contains inference types/regions",
+ substs);
+ })
+ });
+ ImplMethod {
+ method: node_item.item,
+ substs: substs,
+ is_provided: node_item.node.is_from_trait(),
+ }
+ }
+ None => {
+ bug!("method {:?} not found in {:?}", name, impl_def_id)
+ }
+ }
+}
+
+pub fn interpret_start_points<'a, 'tcx>(
+ tcx: TyCtxt<'a, 'tcx, 'tcx>,
+ mir_map: &MirMap<'tcx>,
+) {
+ let initial_indentation = ::log_settings::settings().indentation;
+ for (&id, mir) in &mir_map.map {
+ for attr in tcx.map.attrs(id) {
+ use syntax::attr::AttrMetaMethods;
+ if attr.check_name("miri_run") {
+ let item = tcx.map.expect_item(id);
+
+ ::log_settings::settings().indentation = initial_indentation;
+
+ debug!("Interpreting: {}", item.name);
+
+ let mut gecx = GlobalEvalContext::new(tcx, mir_map);
+ match gecx.call(mir) {
+ Ok(Some(return_ptr)) => if log_enabled!(::log::LogLevel::Debug) {
+ gecx.memory.dump(return_ptr.alloc_id);
+ },
+ Ok(None) => warn!("diverging function returned"),
+ Err(_e) => {
+ // TODO(solson): Detect whether the error was already reported or not.
+ // tcx.sess.err(&e.to_string());
+ }
+ }
+ }
+ }
+ }
+}
+
+// TODO(solson): Upstream these methods into rustc::ty::layout.
+
+trait IntegerExt {
+ fn size(self) -> Size;
+}
+
+impl IntegerExt for layout::Integer {
+ fn size(self) -> Size {
+ use rustc::ty::layout::Integer::*;
+ match self {
+ I1 | I8 => Size::from_bits(8),
+ I16 => Size::from_bits(16),
+ I32 => Size::from_bits(32),
+ I64 => Size::from_bits(64),
+ }
+ }
+}
+
+trait StructExt {
+ fn field_offset(&self, index: usize) -> Size;
+}
+
+impl StructExt for layout::Struct {
+ fn field_offset(&self, index: usize) -> Size {
+ if index == 0 {
+ Size::from_bytes(0)
+ } else {
+ self.offset_after_field[index - 1]
+ }
+ }
+}
filling_drop,
question_mark,
rustc_private,
+ pub_restricted,
)]
// From rustc.
projects / rust.git / commitdiff