+use rustc::mir;
+use rustc::traits::Reveal;
+use rustc::ty::layout::Layout;
+use rustc::ty::{self, Ty};
+
+use rustc_miri::interpret::{
+ EvalError, EvalResult,
+ Lvalue, LvalueExtra,
+ PrimVal, PrimValKind, Value, Pointer,
+ HasMemory,
+ EvalContext,
+};
+
+use helpers::EvalContextExt as HelperEvalContextExt;
+
+pub trait EvalContextExt<'tcx> {
+ fn call_intrinsic(
+ &mut self,
+ instance: ty::Instance<'tcx>,
+ args: &[mir::Operand<'tcx>],
+ dest: Lvalue<'tcx>,
+ dest_ty: Ty<'tcx>,
+ dest_layout: &'tcx Layout,
+ target: mir::BasicBlock,
+ ) -> EvalResult<'tcx>;
+}
+
+impl<'a, 'tcx> EvalContextExt<'tcx> for EvalContext<'a, 'tcx, super::Evaluator> {
+ fn call_intrinsic(
+ &mut self,
+ instance: ty::Instance<'tcx>,
+ args: &[mir::Operand<'tcx>],
+ dest: Lvalue<'tcx>,
+ dest_ty: Ty<'tcx>,
+ dest_layout: &'tcx Layout,
+ target: mir::BasicBlock,
+ ) -> EvalResult<'tcx> {
+ let arg_vals: EvalResult<Vec<Value>> = args.iter()
+ .map(|arg| self.eval_operand(arg))
+ .collect();
+ let arg_vals = arg_vals?;
+ let i32 = self.tcx.types.i32;
+ let isize = self.tcx.types.isize;
+ let usize = self.tcx.types.usize;
+ let f32 = self.tcx.types.f32;
+ let f64 = self.tcx.types.f64;
+ let substs = instance.substs;
+
+ let intrinsic_name = &self.tcx.item_name(instance.def_id()).as_str()[..];
+ match intrinsic_name {
+ "add_with_overflow" =>
+ self.intrinsic_with_overflow(mir::BinOp::Add, &args[0], &args[1], dest, dest_ty)?,
+
+ "sub_with_overflow" =>
+ self.intrinsic_with_overflow(mir::BinOp::Sub, &args[0], &args[1], dest, dest_ty)?,
+
+ "mul_with_overflow" =>
+ self.intrinsic_with_overflow(mir::BinOp::Mul, &args[0], &args[1], dest, dest_ty)?,
+
+
+ "arith_offset" => {
+ let offset = self.value_to_primval(arg_vals[1], isize)?.to_i128()? as i64;
+ let ptr = arg_vals[0].into_ptr(&self.memory)?;
+ let result_ptr = self.wrapping_pointer_offset(ptr, substs.type_at(0), offset)?;
+ self.write_ptr(dest, result_ptr, dest_ty)?;
+ }
+
+ "assume" => {
+ let bool = self.tcx.types.bool;
+ let cond = self.value_to_primval(arg_vals[0], bool)?.to_bool()?;
+ if !cond { return Err(EvalError::AssumptionNotHeld); }
+ }
+
+ "atomic_load" |
+ "atomic_load_relaxed" |
+ "atomic_load_acq" |
+ "volatile_load" => {
+ let ty = substs.type_at(0);
+ let ptr = arg_vals[0].into_ptr(&self.memory)?;
+ self.write_value(Value::by_ref(ptr), dest, ty)?;
+ }
+
+ "atomic_store" |
+ "atomic_store_relaxed" |
+ "atomic_store_rel" |
+ "volatile_store" => {
+ let ty = substs.type_at(0);
+ let dest = arg_vals[0].into_ptr(&self.memory)?;
+ self.write_value_to_ptr(arg_vals[1], dest, ty)?;
+ }
+
+ "atomic_fence_acq" => {
+ // we are inherently singlethreaded and singlecored, this is a nop
+ }
+
+ _ if intrinsic_name.starts_with("atomic_xchg") => {
+ let ty = substs.type_at(0);
+ let ptr = arg_vals[0].into_ptr(&self.memory)?;
+ let change = self.value_to_primval(arg_vals[1], ty)?;
+ let old = self.read_value(ptr, ty)?;
+ let old = match old {
+ Value::ByVal(val) => val,
+ Value::ByRef { .. } => bug!("just read the value, can't be byref"),
+ Value::ByValPair(..) => bug!("atomic_xchg doesn't work with nonprimitives"),
+ };
+ self.write_primval(dest, old, ty)?;
+ self.write_primval(Lvalue::from_primval_ptr(ptr), change, ty)?;
+ }
+
+ _ if intrinsic_name.starts_with("atomic_cxchg") => {
+ let ty = substs.type_at(0);
+ let ptr = arg_vals[0].into_ptr(&self.memory)?;
+ let expect_old = self.value_to_primval(arg_vals[1], ty)?;
+ let change = self.value_to_primval(arg_vals[2], ty)?;
+ let old = self.read_value(ptr, ty)?;
+ let old = match old {
+ Value::ByVal(val) => val,
+ Value::ByRef { .. } => bug!("just read the value, can't be byref"),
+ Value::ByValPair(..) => bug!("atomic_cxchg doesn't work with nonprimitives"),
+ };
+ let (val, _) = self.binary_op(mir::BinOp::Eq, old, ty, expect_old, ty)?;
+ let dest = self.force_allocation(dest)?.to_ptr()?;
+ self.write_pair_to_ptr(old, val, dest, dest_ty)?;
+ self.write_primval(Lvalue::from_primval_ptr(ptr), change, ty)?;
+ }
+
+ "atomic_or" | "atomic_or_acq" | "atomic_or_rel" | "atomic_or_acqrel" | "atomic_or_relaxed" |
+ "atomic_xor" | "atomic_xor_acq" | "atomic_xor_rel" | "atomic_xor_acqrel" | "atomic_xor_relaxed" |
+ "atomic_and" | "atomic_and_acq" | "atomic_and_rel" | "atomic_and_acqrel" | "atomic_and_relaxed" |
+ "atomic_xadd" | "atomic_xadd_acq" | "atomic_xadd_rel" | "atomic_xadd_acqrel" | "atomic_xadd_relaxed" |
+ "atomic_xsub" | "atomic_xsub_acq" | "atomic_xsub_rel" | "atomic_xsub_acqrel" | "atomic_xsub_relaxed" => {
+ let ty = substs.type_at(0);
+ let ptr = arg_vals[0].into_ptr(&self.memory)?;
+ let change = self.value_to_primval(arg_vals[1], ty)?;
+ let old = self.read_value(ptr, ty)?;
+ let old = match old {
+ Value::ByVal(val) => val,
+ Value::ByRef { .. } => bug!("just read the value, can't be byref"),
+ Value::ByValPair(..) => bug!("atomic_xadd_relaxed doesn't work with nonprimitives"),
+ };
+ self.write_primval(dest, old, ty)?;
+ let op = match intrinsic_name.split('_').nth(1).unwrap() {
+ "or" => mir::BinOp::BitOr,
+ "xor" => mir::BinOp::BitXor,
+ "and" => mir::BinOp::BitAnd,
+ "xadd" => mir::BinOp::Add,
+ "xsub" => mir::BinOp::Sub,
+ _ => bug!(),
+ };
+ // FIXME: what do atomics do on overflow?
+ let (val, _) = self.binary_op(op, old, ty, change, ty)?;
+ self.write_primval(Lvalue::from_primval_ptr(ptr), val, ty)?;
+ },
+
+ "breakpoint" => unimplemented!(), // halt miri
+
+ "copy" |
+ "copy_nonoverlapping" => {
+ let elem_ty = substs.type_at(0);
+ let elem_size = self.type_size(elem_ty)?.expect("cannot copy unsized value");
+ let count = self.value_to_primval(arg_vals[2], usize)?.to_u64()?;
+ if count * elem_size != 0 {
+ // TODO: We do not even validate alignment for the 0-bytes case. libstd relies on this in vec::IntoIter::next.
+ // Also see the write_bytes intrinsic.
+ let elem_align = self.type_align(elem_ty)?;
+ let src = arg_vals[0].into_ptr(&self.memory)?;
+ let dest = arg_vals[1].into_ptr(&self.memory)?;
+ self.memory.copy(src, dest, count * elem_size, elem_align, intrinsic_name.ends_with("_nonoverlapping"))?;
+ }
+ }
+
+ "ctpop" |
+ "cttz" |
+ "cttz_nonzero" |
+ "ctlz" |
+ "ctlz_nonzero" |
+ "bswap" => {
+ let ty = substs.type_at(0);
+ let num = self.value_to_primval(arg_vals[0], ty)?.to_bytes()?;
+ let kind = self.ty_to_primval_kind(ty)?;
+ let num = if intrinsic_name.ends_with("_nonzero") {
+ if num == 0 {
+ return Err(EvalError::Intrinsic(format!("{} called on 0", intrinsic_name)))
+ }
+ numeric_intrinsic(intrinsic_name.trim_right_matches("_nonzero"), num, kind)?
+ } else {
+ numeric_intrinsic(intrinsic_name, num, kind)?
+ };
+ self.write_primval(dest, num, ty)?;
+ }
+
+ "discriminant_value" => {
+ let ty = substs.type_at(0);
+ let adt_ptr = arg_vals[0].into_ptr(&self.memory)?.to_ptr()?;
+ let discr_val = self.read_discriminant_value(adt_ptr, ty)?;
+ self.write_primval(dest, PrimVal::Bytes(discr_val), dest_ty)?;
+ }
+
+ "sinf32" | "fabsf32" | "cosf32" |
+ "sqrtf32" | "expf32" | "exp2f32" |
+ "logf32" | "log10f32" | "log2f32" |
+ "floorf32" | "ceilf32" | "truncf32" => {
+ let f = self.value_to_primval(arg_vals[0], f32)?.to_f32()?;
+ let f = match intrinsic_name {
+ "sinf32" => f.sin(),
+ "fabsf32" => f.abs(),
+ "cosf32" => f.cos(),
+ "sqrtf32" => f.sqrt(),
+ "expf32" => f.exp(),
+ "exp2f32" => f.exp2(),
+ "logf32" => f.ln(),
+ "log10f32" => f.log10(),
+ "log2f32" => f.log2(),
+ "floorf32" => f.floor(),
+ "ceilf32" => f.ceil(),
+ "truncf32" => f.trunc(),
+ _ => bug!(),
+ };
+ self.write_primval(dest, PrimVal::from_f32(f), dest_ty)?;
+ }
+
+ "sinf64" | "fabsf64" | "cosf64" |
+ "sqrtf64" | "expf64" | "exp2f64" |
+ "logf64" | "log10f64" | "log2f64" |
+ "floorf64" | "ceilf64" | "truncf64" => {
+ let f = self.value_to_primval(arg_vals[0], f64)?.to_f64()?;
+ let f = match intrinsic_name {
+ "sinf64" => f.sin(),
+ "fabsf64" => f.abs(),
+ "cosf64" => f.cos(),
+ "sqrtf64" => f.sqrt(),
+ "expf64" => f.exp(),
+ "exp2f64" => f.exp2(),
+ "logf64" => f.ln(),
+ "log10f64" => f.log10(),
+ "log2f64" => f.log2(),
+ "floorf64" => f.floor(),
+ "ceilf64" => f.ceil(),
+ "truncf64" => f.trunc(),
+ _ => bug!(),
+ };
+ self.write_primval(dest, PrimVal::from_f64(f), dest_ty)?;
+ }
+
+ "fadd_fast" | "fsub_fast" | "fmul_fast" | "fdiv_fast" | "frem_fast" => {
+ let ty = substs.type_at(0);
+ let a = self.value_to_primval(arg_vals[0], ty)?;
+ let b = self.value_to_primval(arg_vals[1], ty)?;
+ let op = match intrinsic_name {
+ "fadd_fast" => mir::BinOp::Add,
+ "fsub_fast" => mir::BinOp::Sub,
+ "fmul_fast" => mir::BinOp::Mul,
+ "fdiv_fast" => mir::BinOp::Div,
+ "frem_fast" => mir::BinOp::Rem,
+ _ => bug!(),
+ };
+ let result = self.binary_op(op, a, ty, b, ty)?;
+ self.write_primval(dest, result.0, dest_ty)?;
+ }
+
+ "likely" |
+ "unlikely" |
+ "forget" => {}
+
+ "init" => {
+ let size = self.type_size(dest_ty)?.expect("cannot zero unsized value");
+ let init = |this: &mut Self, val: Value| {
+ let zero_val = match val {
+ Value::ByRef { ptr, aligned } => {
+ // These writes have no alignment restriction anyway.
+ this.memory.write_repeat(ptr, 0, size)?;
+ Value::ByRef { ptr, aligned }
+ },
+ // TODO(solson): Revisit this, it's fishy to check for Undef here.
+ Value::ByVal(PrimVal::Undef) => match this.ty_to_primval_kind(dest_ty) {
+ Ok(_) => Value::ByVal(PrimVal::Bytes(0)),
+ Err(_) => {
+ let ptr = this.alloc_ptr_with_substs(dest_ty, substs)?;
+ let ptr = Pointer::from(PrimVal::Ptr(ptr));
+ this.memory.write_repeat(ptr, 0, size)?;
+ Value::by_ref(ptr)
+ }
+ },
+ Value::ByVal(_) => Value::ByVal(PrimVal::Bytes(0)),
+ Value::ByValPair(..) =>
+ Value::ByValPair(PrimVal::Bytes(0), PrimVal::Bytes(0)),
+ };
+ Ok(zero_val)
+ };
+ match dest {
+ Lvalue::Local { frame, local } => self.modify_local(frame, local, init)?,
+ Lvalue::Ptr { ptr, extra: LvalueExtra::None, aligned: true } => self.memory.write_repeat(ptr, 0, size)?,
+ Lvalue::Ptr { .. } => bug!("init intrinsic tried to write to fat or unaligned ptr target"),
+ Lvalue::Global(cid) => self.modify_global(cid, init)?,
+ }
+ }
+
+ "min_align_of" => {
+ let elem_ty = substs.type_at(0);
+ let elem_align = self.type_align(elem_ty)?;
+ let align_val = PrimVal::from_u128(elem_align as u128);
+ self.write_primval(dest, align_val, dest_ty)?;
+ }
+
+ "pref_align_of" => {
+ let ty = substs.type_at(0);
+ let layout = self.type_layout(ty)?;
+ let align = layout.align(&self.tcx.data_layout).pref();
+ let align_val = PrimVal::from_u128(align as u128);
+ self.write_primval(dest, align_val, dest_ty)?;
+ }
+
+ "move_val_init" => {
+ let ty = substs.type_at(0);
+ let ptr = arg_vals[0].into_ptr(&self.memory)?;
+ self.write_value_to_ptr(arg_vals[1], ptr, ty)?;
+ }
+
+ "needs_drop" => {
+ let ty = substs.type_at(0);
+ let env = ty::ParamEnv::empty(Reveal::All);
+ let needs_drop = ty.needs_drop(self.tcx, env);
+ self.write_primval(dest, PrimVal::from_bool(needs_drop), dest_ty)?;
+ }
+
+ "offset" => {
+ let offset = self.value_to_primval(arg_vals[1], isize)?.to_i128()? as i64;
+ let ptr = arg_vals[0].into_ptr(&self.memory)?;
+ let result_ptr = self.pointer_offset(ptr, substs.type_at(0), offset)?;
+ self.write_ptr(dest, result_ptr, dest_ty)?;
+ }
+
+ "overflowing_sub" => {
+ self.intrinsic_overflowing(mir::BinOp::Sub, &args[0], &args[1], dest, dest_ty)?;
+ }
+
+ "overflowing_mul" => {
+ self.intrinsic_overflowing(mir::BinOp::Mul, &args[0], &args[1], dest, dest_ty)?;
+ }
+
+ "overflowing_add" => {
+ self.intrinsic_overflowing(mir::BinOp::Add, &args[0], &args[1], dest, dest_ty)?;
+ }
+
+ "powf32" => {
+ let f = self.value_to_primval(arg_vals[0], f32)?.to_f32()?;
+ let f2 = self.value_to_primval(arg_vals[1], f32)?.to_f32()?;
+ self.write_primval(dest, PrimVal::from_f32(f.powf(f2)), dest_ty)?;
+ }
+
+ "powf64" => {
+ let f = self.value_to_primval(arg_vals[0], f64)?.to_f64()?;
+ let f2 = self.value_to_primval(arg_vals[1], f64)?.to_f64()?;
+ self.write_primval(dest, PrimVal::from_f64(f.powf(f2)), dest_ty)?;
+ }
+
+ "fmaf32" => {
+ let a = self.value_to_primval(arg_vals[0], f32)?.to_f32()?;
+ let b = self.value_to_primval(arg_vals[1], f32)?.to_f32()?;
+ let c = self.value_to_primval(arg_vals[2], f32)?.to_f32()?;
+ self.write_primval(dest, PrimVal::from_f32(a * b + c), dest_ty)?;
+ }
+
+ "fmaf64" => {
+ let a = self.value_to_primval(arg_vals[0], f64)?.to_f64()?;
+ let b = self.value_to_primval(arg_vals[1], f64)?.to_f64()?;
+ let c = self.value_to_primval(arg_vals[2], f64)?.to_f64()?;
+ self.write_primval(dest, PrimVal::from_f64(a * b + c), dest_ty)?;
+ }
+
+ "powif32" => {
+ let f = self.value_to_primval(arg_vals[0], f32)?.to_f32()?;
+ let i = self.value_to_primval(arg_vals[1], i32)?.to_i128()?;
+ self.write_primval(dest, PrimVal::from_f32(f.powi(i as i32)), dest_ty)?;
+ }
+
+ "powif64" => {
+ let f = self.value_to_primval(arg_vals[0], f64)?.to_f64()?;
+ let i = self.value_to_primval(arg_vals[1], i32)?.to_i128()?;
+ self.write_primval(dest, PrimVal::from_f64(f.powi(i as i32)), dest_ty)?;
+ }
+
+ "size_of" => {
+ let ty = substs.type_at(0);
+ let size = self.type_size(ty)?.expect("size_of intrinsic called on unsized value") as u128;
+ self.write_primval(dest, PrimVal::from_u128(size), dest_ty)?;
+ }
+
+ "size_of_val" => {
+ let ty = substs.type_at(0);
+ let (size, _) = self.size_and_align_of_dst(ty, arg_vals[0])?;
+ self.write_primval(dest, PrimVal::from_u128(size as u128), dest_ty)?;
+ }
+
+ "min_align_of_val" |
+ "align_of_val" => {
+ let ty = substs.type_at(0);
+ let (_, align) = self.size_and_align_of_dst(ty, arg_vals[0])?;
+ self.write_primval(dest, PrimVal::from_u128(align as u128), dest_ty)?;
+ }
+
+ "type_name" => {
+ let ty = substs.type_at(0);
+ let ty_name = ty.to_string();
+ let s = self.str_to_value(&ty_name)?;
+ self.write_value(s, dest, dest_ty)?;
+ }
+ "type_id" => {
+ let ty = substs.type_at(0);
+ let n = self.tcx.type_id_hash(ty);
+ self.write_primval(dest, PrimVal::Bytes(n as u128), dest_ty)?;
+ }
+
+ "transmute" => {
+ let src_ty = substs.type_at(0);
+ let ptr = self.force_allocation(dest)?.to_ptr()?;
+ self.write_maybe_aligned_mut(/*aligned*/false, |ectx| {
+ ectx.write_value_to_ptr(arg_vals[0], ptr.into(), src_ty)
+ })?;
+ }
+
+ "unchecked_shl" => {
+ let bits = self.type_size(dest_ty)?.expect("intrinsic can't be called on unsized type") as u128 * 8;
+ let rhs = self.value_to_primval(arg_vals[1], substs.type_at(0))?.to_bytes()?;
+ if rhs >= bits {
+ return Err(EvalError::Intrinsic(format!("Overflowing shift by {} in unchecked_shl", rhs)));
+ }
+ self.intrinsic_overflowing(mir::BinOp::Shl, &args[0], &args[1], dest, dest_ty)?;
+ }
+
+ "unchecked_shr" => {
+ let bits = self.type_size(dest_ty)?.expect("intrinsic can't be called on unsized type") as u128 * 8;
+ let rhs = self.value_to_primval(arg_vals[1], substs.type_at(0))?.to_bytes()?;
+ if rhs >= bits {
+ return Err(EvalError::Intrinsic(format!("Overflowing shift by {} in unchecked_shr", rhs)));
+ }
+ self.intrinsic_overflowing(mir::BinOp::Shr, &args[0], &args[1], dest, dest_ty)?;
+ }
+
+ "unchecked_div" => {
+ let rhs = self.value_to_primval(arg_vals[1], substs.type_at(0))?.to_bytes()?;
+ if rhs == 0 {
+ return Err(EvalError::Intrinsic(format!("Division by 0 in unchecked_div")));
+ }
+ self.intrinsic_overflowing(mir::BinOp::Div, &args[0], &args[1], dest, dest_ty)?;
+ }
+
+ "unchecked_rem" => {
+ let rhs = self.value_to_primval(arg_vals[1], substs.type_at(0))?.to_bytes()?;
+ if rhs == 0 {
+ return Err(EvalError::Intrinsic(format!("Division by 0 in unchecked_rem")));
+ }
+ self.intrinsic_overflowing(mir::BinOp::Rem, &args[0], &args[1], dest, dest_ty)?;
+ }
+
+ "uninit" => {
+ let size = dest_layout.size(&self.tcx.data_layout).bytes();
+ let uninit = |this: &mut Self, val: Value| {
+ match val {
+ Value::ByRef { ptr, aligned } => {
+ this.memory.mark_definedness(ptr, size, false)?;
+ Ok(Value::ByRef { ptr, aligned })
+ },
+ _ => Ok(Value::ByVal(PrimVal::Undef)),
+ }
+ };
+ match dest {
+ Lvalue::Local { frame, local } => self.modify_local(frame, local, uninit)?,
+ Lvalue::Ptr { ptr, extra: LvalueExtra::None, aligned: true } =>
+ self.memory.mark_definedness(ptr, size, false)?,
+ Lvalue::Ptr { .. } => bug!("uninit intrinsic tried to write to fat or unaligned ptr target"),
+ Lvalue::Global(cid) => self.modify_global(cid, uninit)?,
+ }
+ }
+
+ "write_bytes" => {
+ let u8 = self.tcx.types.u8;
+ let ty = substs.type_at(0);
+ let ty_align = self.type_align(ty)?;
+ let val_byte = self.value_to_primval(arg_vals[1], u8)?.to_u128()? as u8;
+ let size = self.type_size(ty)?.expect("write_bytes() type must be sized");
+ let ptr = arg_vals[0].into_ptr(&self.memory)?;
+ let count = self.value_to_primval(arg_vals[2], usize)?.to_u64()?;
+ if count > 0 {
+ // HashMap relies on write_bytes on a NULL ptr with count == 0 to work
+ // TODO: Should we, at least, validate the alignment? (Also see the copy intrinsic)
+ self.memory.check_align(ptr, ty_align)?;
+ self.memory.write_repeat(ptr, val_byte, size * count)?;
+ }
+ }
+
+ name => return Err(EvalError::Unimplemented(format!("unimplemented intrinsic: {}", name))),
+ }
+
+ self.goto_block(target);
+
+ // 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(())
+ }
+}
+
+fn numeric_intrinsic<'tcx>(
+ name: &str,
+ bytes: u128,
+ kind: PrimValKind
+) -> EvalResult<'tcx, PrimVal> {
+ macro_rules! integer_intrinsic {
+ ($method:ident) => ({
+ use rustc_miri::interpret::PrimValKind::*;
+ let result_bytes = match kind {
+ I8 => (bytes as i8).$method() as u128,
+ U8 => (bytes as u8).$method() as u128,
+ I16 => (bytes as i16).$method() as u128,
+ U16 => (bytes as u16).$method() as u128,
+ I32 => (bytes as i32).$method() as u128,
+ U32 => (bytes as u32).$method() as u128,
+ I64 => (bytes as i64).$method() as u128,
+ U64 => (bytes as u64).$method() as u128,
+ I128 => (bytes as i128).$method() as u128,
+ U128 => bytes.$method() as u128,
+ _ => bug!("invalid `{}` argument: {:?}", name, bytes),
+ };
+
+ PrimVal::Bytes(result_bytes)
+ });
+ }
+
+ let result_val = match name {
+ "bswap" => integer_intrinsic!(swap_bytes),
+ "ctlz" => integer_intrinsic!(leading_zeros),
+ "ctpop" => integer_intrinsic!(count_ones),
+ "cttz" => integer_intrinsic!(trailing_zeros),
+ _ => bug!("not a numeric intrinsic: {}", name),
+ };
+
+ Ok(result_val)
+}