From: Oliver Scherer Date: Fri, 7 Jun 2019 17:22:42 +0000 (+0200) Subject: Get rid of special const intrinsic query in favour of `const_eval` X-Git-Url: https://git.lizzy.rs/?a=commitdiff_plain;h=0de9485038a5a068644efbfa397feec6d02e05ea;p=rust.git Get rid of special const intrinsic query in favour of `const_eval` --- diff --git a/src/librustc/mir/interpret/error.rs b/src/librustc/mir/interpret/error.rs index 09c822f7508..67b3ce0e63f 100644 --- a/src/librustc/mir/interpret/error.rs +++ b/src/librustc/mir/interpret/error.rs @@ -213,6 +213,15 @@ fn print_backtrace(backtrace: &mut Backtrace) { eprintln!("\n\nAn error occurred in miri:\n{:?}", backtrace); } +impl From for InterpErrorInfo<'tcx> { + fn from(err: ErrorHandled) -> Self { + match err { + ErrorHandled::Reported => err_inval!(ReferencedConstant), + ErrorHandled::TooGeneric => err_inval!(TooGeneric), + }.into() + } +} + impl<'tcx> From> for InterpErrorInfo<'tcx> { fn from(kind: InterpError<'tcx>) -> Self { let backtrace = match env::var("RUSTC_CTFE_BACKTRACE") { diff --git a/src/librustc/query/mod.rs b/src/librustc/query/mod.rs index 4ebc2e72490..c7260945295 100644 --- a/src/librustc/query/mod.rs +++ b/src/librustc/query/mod.rs @@ -462,15 +462,6 @@ no_force desc { "extract field of const" } } - - /// Produces an absolute path representation of the given type. See also the documentation - /// on `std::any::type_name`. - query type_name(key: Ty<'tcx>) -> &'tcx ty::Const<'tcx> { - eval_always - no_force - desc { "get absolute path of type" } - } - } TypeChecking { diff --git a/src/librustc_codegen_llvm/intrinsic.rs b/src/librustc_codegen_llvm/intrinsic.rs index 5fbfe9138f2..3f3c5ac1460 100644 --- a/src/librustc_codegen_llvm/intrinsic.rs +++ b/src/librustc_codegen_llvm/intrinsic.rs @@ -15,6 +15,7 @@ use rustc_codegen_ssa::base::{to_immediate, wants_msvc_seh, compare_simd_types}; use rustc::ty::{self, Ty}; use rustc::ty::layout::{self, LayoutOf, HasTyCtxt, Primitive}; +use rustc::mir::interpret::GlobalId; use rustc_codegen_ssa::common::{IntPredicate, TypeKind}; use rustc::hir; use syntax::ast::{self, FloatTy}; @@ -81,13 +82,14 @@ fn get_simple_intrinsic(cx: &CodegenCx<'ll, '_>, name: &str) -> Option<&'ll Valu impl IntrinsicCallMethods<'tcx> for Builder<'a, 'll, 'tcx> { fn codegen_intrinsic_call( &mut self, - callee_ty: Ty<'tcx>, + instance: ty::Instance<'tcx>, fn_ty: &FnType<'tcx, Ty<'tcx>>, args: &[OperandRef<'tcx, &'ll Value>], llresult: &'ll Value, span: Span, ) { let tcx = self.tcx; + let callee_ty = instance.ty(tcx); let (def_id, substs) = match callee_ty.sty { ty::FnDef(def_id, substs) => (def_id, substs), @@ -133,10 +135,6 @@ fn codegen_intrinsic_call( let llfn = self.get_intrinsic(&("llvm.debugtrap")); self.call(llfn, &[], None) } - "size_of" => { - let tp_ty = substs.type_at(0); - self.const_usize(self.size_of(tp_ty).bytes()) - } "va_start" => { self.va_start(args[0].immediate()) } @@ -188,10 +186,6 @@ fn codegen_intrinsic_call( self.const_usize(self.size_of(tp_ty).bytes()) } } - "min_align_of" => { - let tp_ty = substs.type_at(0); - self.const_usize(self.align_of(tp_ty).bytes()) - } "min_align_of_val" => { let tp_ty = substs.type_at(0); if let OperandValue::Pair(_, meta) = args[0].val { @@ -201,18 +195,19 @@ fn codegen_intrinsic_call( self.const_usize(self.align_of(tp_ty).bytes()) } } - "pref_align_of" => { - let tp_ty = substs.type_at(0); - self.const_usize(self.layout_of(tp_ty).align.pref.bytes()) - } + "size_of" | + "pref_align_of" | + "min_align_of" | + "needs_drop" | + "type_id" | "type_name" => { - let tp_ty = substs.type_at(0); - let ty_name = self.tcx.type_name(tp_ty); + let gid = GlobalId { + instance, + promoted: None, + }; + let ty_name = self.tcx.const_eval(ty::ParamEnv::reveal_all().and(gid)).unwrap(); OperandRef::from_const(self, ty_name).immediate_or_packed_pair(self) } - "type_id" => { - self.const_u64(self.tcx.type_id_hash(substs.type_at(0))) - } "init" => { let ty = substs.type_at(0); if !self.layout_of(ty).is_zst() { @@ -235,11 +230,6 @@ fn codegen_intrinsic_call( "uninit" | "forget" => { return; } - "needs_drop" => { - let tp_ty = substs.type_at(0); - - self.const_bool(self.type_needs_drop(tp_ty)) - } "offset" => { let ptr = args[0].immediate(); let offset = args[1].immediate(); diff --git a/src/librustc_codegen_ssa/mir/block.rs b/src/librustc_codegen_ssa/mir/block.rs index 8829a33992a..1bb0ea5dae4 100644 --- a/src/librustc_codegen_ssa/mir/block.rs +++ b/src/librustc_codegen_ssa/mir/block.rs @@ -667,8 +667,7 @@ fn codegen_call_terminator<'b>( }).collect(); - let callee_ty = instance.as_ref().unwrap().ty(bx.tcx()); - bx.codegen_intrinsic_call(callee_ty, &fn_ty, &args, dest, + bx.codegen_intrinsic_call(*instance.as_ref().unwrap(), &fn_ty, &args, dest, terminator.source_info.span); if let ReturnDest::IndirectOperand(dst, _) = ret_dest { diff --git a/src/librustc_codegen_ssa/traits/intrinsic.rs b/src/librustc_codegen_ssa/traits/intrinsic.rs index ede30a0bed7..7c79cd60210 100644 --- a/src/librustc_codegen_ssa/traits/intrinsic.rs +++ b/src/librustc_codegen_ssa/traits/intrinsic.rs @@ -1,6 +1,6 @@ use super::BackendTypes; use crate::mir::operand::OperandRef; -use rustc::ty::Ty; +use rustc::ty::{self, Ty}; use rustc_target::abi::call::FnType; use syntax_pos::Span; @@ -10,7 +10,7 @@ pub trait IntrinsicCallMethods<'tcx>: BackendTypes { /// add them to librustc_codegen_llvm/context.rs fn codegen_intrinsic_call( &mut self, - callee_ty: Ty<'tcx>, + instance: ty::Instance<'tcx>, fn_ty: &FnType<'tcx, Ty<'tcx>>, args: &[OperandRef<'tcx, Self::Value>], llresult: Self::Value, diff --git a/src/librustc_mir/const_eval.rs b/src/librustc_mir/const_eval.rs index 3f53f842f31..435159827e6 100644 --- a/src/librustc_mir/const_eval.rs +++ b/src/librustc_mir/const_eval.rs @@ -15,6 +15,7 @@ use rustc::ty::layout::{self, LayoutOf, VariantIdx}; use rustc::traits::Reveal; use rustc_data_structures::fx::FxHashMap; +use crate::interpret::eval_nullary_intrinsic; use syntax::source_map::{Span, DUMMY_SP}; @@ -602,6 +603,23 @@ pub fn const_eval_provider<'tcx>( other => return other, } } + + // We call `const_eval` for zero arg intrinsics, too, in order to cache their value. + // Catch such calls and evaluate them instead of trying to load a constant's MIR. + if let ty::InstanceDef::Intrinsic(def_id) = key.value.instance.def { + let ty = key.value.instance.ty(tcx); + let substs = match ty.sty { + ty::FnDef(_, substs) => substs, + _ => bug!("intrinsic with type {:?}", ty), + }; + return eval_nullary_intrinsic(tcx, key.param_env, def_id, substs) + .map_err(|error| { + let span = tcx.def_span(def_id); + let error = ConstEvalErr { error: error.kind, stacktrace: vec![], span }; + error.report_as_error(tcx.at(span), "could not evaluate nullary intrinsic") + }) + } + tcx.const_eval_raw(key).and_then(|val| { validate_and_turn_into_const(tcx, val, key) }) diff --git a/src/librustc_mir/interpret/eval_context.rs b/src/librustc_mir/interpret/eval_context.rs index 054b65f0e1a..78996ed6939 100644 --- a/src/librustc_mir/interpret/eval_context.rs +++ b/src/librustc_mir/interpret/eval_context.rs @@ -14,7 +14,6 @@ use rustc::ty::query::TyCtxtAt; use rustc_data_structures::indexed_vec::IndexVec; use rustc::mir::interpret::{ - ErrorHandled, GlobalId, Scalar, Pointer, FrameInfo, AllocId, InterpResult, truncate, sign_extend, }; @@ -672,14 +671,7 @@ pub fn const_eval_raw( // Our result will later be validated anyway, and there seems no good reason // to have to fail early here. This is also more consistent with // `Memory::get_static_alloc` which has to use `const_eval_raw` to avoid cycles. - let val = self.tcx.const_eval_raw(param_env.and(gid)).map_err(|err| { - match err { - ErrorHandled::Reported => - err_inval!(ReferencedConstant), - ErrorHandled::TooGeneric => - err_inval!(TooGeneric), - } - })?; + let val = self.tcx.const_eval_raw(param_env.and(gid))?; self.raw_const_to_mplace(val) } diff --git a/src/librustc_mir/interpret/intrinsics.rs b/src/librustc_mir/interpret/intrinsics.rs index 0f2305e03ff..ec09e69ec85 100644 --- a/src/librustc_mir/interpret/intrinsics.rs +++ b/src/librustc_mir/interpret/intrinsics.rs @@ -5,17 +5,18 @@ use syntax::symbol::Symbol; use rustc::ty; use rustc::ty::layout::{LayoutOf, Primitive, Size}; +use rustc::ty::subst::SubstsRef; +use rustc::hir::def_id::DefId; +use rustc::ty::TyCtxt; use rustc::mir::BinOp; -use rustc::mir::interpret::{InterpResult, Scalar}; +use rustc::mir::interpret::{InterpResult, Scalar, GlobalId, ConstValue}; use super::{ - Machine, PlaceTy, OpTy, InterpCx, Immediate, + Machine, PlaceTy, OpTy, InterpCx, }; mod type_name; -pub use type_name::*; - fn numeric_intrinsic<'tcx, Tag>( name: &str, bits: u128, @@ -37,6 +38,50 @@ fn numeric_intrinsic<'tcx, Tag>( Ok(Scalar::from_uint(bits_out, size)) } +/// The logic for all nullary intrinsics is implemented here. These intrinsics don't get evaluated +/// inside an `InterpCx` and instead have their value computed directly from rustc internal info. +crate fn eval_nullary_intrinsic<'tcx>( + tcx: TyCtxt<'tcx>, + param_env: ty::ParamEnv<'tcx>, + def_id: DefId, + substs: SubstsRef<'tcx>, +) -> InterpResult<'tcx, &'tcx ty::Const<'tcx>> { + let tp_ty = substs.type_at(0); + let name = &*tcx.item_name(def_id).as_str(); + Ok(match name { + "type_name" => { + let alloc = type_name::alloc_type_name(tcx, tp_ty); + tcx.mk_const(ty::Const { + val: ConstValue::Slice { + data: alloc, + start: 0, + end: alloc.len(), + }, + ty: tcx.mk_static_str(), + }) + }, + "needs_drop" => ty::Const::from_bool(tcx, tp_ty.needs_drop(tcx, param_env)), + "size_of" | + "min_align_of" | + "pref_align_of" => { + let layout = tcx.layout_of(param_env.and(tp_ty)).map_err(|e| err_inval!(Layout(e)))?; + let n = match name { + "pref_align_of" => layout.align.pref.bytes(), + "min_align_of" => layout.align.abi.bytes(), + "size_of" => layout.size.bytes(), + _ => bug!(), + }; + ty::Const::from_usize(tcx, n) + }, + "type_id" => ty::Const::from_bits( + tcx, + tcx.type_id_hash(tp_ty).into(), + param_env.and(tcx.types.u64), + ), + other => bug!("`{}` is not a zero arg intrinsic", other), + }) +} + impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { /// Returns `true` if emulation happened. pub fn emulate_intrinsic( @@ -49,41 +94,19 @@ pub fn emulate_intrinsic( let intrinsic_name = &self.tcx.item_name(instance.def_id()).as_str()[..]; match intrinsic_name { - "min_align_of" => { - let elem_ty = substs.type_at(0); - let elem_align = self.layout_of(elem_ty)?.align.abi.bytes(); - let align_val = Scalar::from_uint(elem_align, dest.layout.size); - self.write_scalar(align_val, dest)?; - } - - "needs_drop" => { - let ty = substs.type_at(0); - let ty_needs_drop = ty.needs_drop(self.tcx.tcx, self.param_env); - let val = Scalar::from_bool(ty_needs_drop); - self.write_scalar(val, dest)?; - } - - "size_of" => { - let ty = substs.type_at(0); - let size = self.layout_of(ty)?.size.bytes() as u128; - let size_val = Scalar::from_uint(size, dest.layout.size); - self.write_scalar(size_val, dest)?; - } - - "type_id" => { - let ty = substs.type_at(0); - let type_id = self.tcx.type_id_hash(ty) as u128; - let id_val = Scalar::from_uint(type_id, dest.layout.size); - self.write_scalar(id_val, dest)?; - } - + "min_align_of" | + "pref_align_of" | + "needs_drop" | + "size_of" | + "type_id" | "type_name" => { - let alloc = alloc_type_name(self.tcx.tcx, substs.type_at(0)); - let name_id = self.tcx.alloc_map.lock().create_memory_alloc(alloc); - let id_ptr = self.memory.tag_static_base_pointer(name_id.into()); - let alloc_len = alloc.size.bytes(); - let name_val = Immediate::new_slice(Scalar::Ptr(id_ptr), alloc_len, self); - self.write_immediate(name_val, dest)?; + let gid = GlobalId { + instance, + promoted: None, + }; + let val = self.tcx.const_eval(self.param_env.and(gid))?; + let val = self.eval_const_to_op(val, None)?; + self.copy_op(val, dest)?; } | "ctpop" diff --git a/src/librustc_mir/interpret/intrinsics/type_name.rs b/src/librustc_mir/interpret/intrinsics/type_name.rs index 032d16a49db..1e765a4ed98 100644 --- a/src/librustc_mir/interpret/intrinsics/type_name.rs +++ b/src/librustc_mir/interpret/intrinsics/type_name.rs @@ -7,7 +7,7 @@ use rustc::hir::map::{DefPathData, DisambiguatedDefPathData}; use rustc::hir::def_id::CrateNum; use std::fmt::Write; -use rustc::mir::interpret::{Allocation, ConstValue}; +use rustc::mir::interpret::Allocation; struct AbsolutePathPrinter<'tcx> { tcx: TyCtxt<'tcx>, @@ -213,22 +213,11 @@ fn write_str(&mut self, s: &str) -> std::fmt::Result { } } -/// Produces an absolute path representation of the given type. See also the documentation on -/// `std::any::type_name` -pub fn type_name<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> &'tcx ty::Const<'tcx> { - let alloc = alloc_type_name(tcx, ty); - tcx.mk_const(ty::Const { - val: ConstValue::Slice { - data: alloc, - start: 0, - end: alloc.len(), - }, - ty: tcx.mk_static_str(), - }) -} - /// Directly returns an `Allocation` containing an absolute path representation of the given type. -pub(super) fn alloc_type_name<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> &'tcx Allocation { +crate fn alloc_type_name<'tcx>( + tcx: TyCtxt<'tcx>, + ty: Ty<'tcx> +) -> &'tcx Allocation { let path = AbsolutePathPrinter { tcx, path: String::new() }.print_type(ty).unwrap().path; let alloc = Allocation::from_byte_aligned_bytes(path.into_bytes()); tcx.intern_const_alloc(alloc) diff --git a/src/librustc_mir/interpret/mod.rs b/src/librustc_mir/interpret/mod.rs index 45d24347e4e..0c61be283df 100644 --- a/src/librustc_mir/interpret/mod.rs +++ b/src/librustc_mir/interpret/mod.rs @@ -34,6 +34,6 @@ pub use self::validity::RefTracking; -pub(super) use self::intrinsics::type_name; - pub use self::intern::intern_const_alloc_recursive; + +crate use self::intrinsics::eval_nullary_intrinsic; diff --git a/src/librustc_mir/lib.rs b/src/librustc_mir/lib.rs index f27db351b74..034ad5b01d3 100644 --- a/src/librustc_mir/lib.rs +++ b/src/librustc_mir/lib.rs @@ -59,5 +59,4 @@ pub fn provide(providers: &mut Providers<'_>) { let (param_env, (value, field)) = param_env_and_value.into_parts(); const_eval::const_field(tcx, param_env, None, field, value) }; - providers.type_name = interpret::type_name; } diff --git a/src/test/compile-fail/issue-44415.rs b/src/test/compile-fail/issue-44415.rs new file mode 100644 index 00000000000..763f8574873 --- /dev/null +++ b/src/test/compile-fail/issue-44415.rs @@ -0,0 +1,11 @@ +#![feature(core_intrinsics)] + +use std::intrinsics; + +struct Foo { + bytes: [u8; unsafe { intrinsics::size_of::() }], + //~^ ERROR cycle detected when const-evaluating + checking + x: usize, +} + +fn main() {} diff --git a/src/test/ui/consts/const-size_of-cycle.stderr b/src/test/ui/consts/const-size_of-cycle.stderr index fdba359e746..1ae39e7563a 100644 --- a/src/test/ui/consts/const-size_of-cycle.stderr +++ b/src/test/ui/consts/const-size_of-cycle.stderr @@ -14,6 +14,11 @@ note: ...which requires const-evaluating `Foo::bytes::{{constant}}#0`... | LL | intrinsics::size_of::() | ^^^^^^^^^^^^^^^^^^^^^^^^^^ +note: ...which requires const-evaluating + checking `std::intrinsics::size_of`... + --> $SRC_DIR/libcore/intrinsics.rs:LL:COL + | +LL | pub fn size_of() -> usize; + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ = note: ...which requires computing layout of `Foo`... = note: ...which requires normalizing `ParamEnvAnd { param_env: ParamEnv { caller_bounds: [], reveal: All, def_id: None }, value: [u8; _] }`... = note: ...which again requires const-evaluating + checking `Foo::bytes::{{constant}}#0`, completing the cycle diff --git a/src/test/ui/issues/issue-44415.rs b/src/test/ui/issues/issue-44415.rs deleted file mode 100644 index 763f8574873..00000000000 --- a/src/test/ui/issues/issue-44415.rs +++ /dev/null @@ -1,11 +0,0 @@ -#![feature(core_intrinsics)] - -use std::intrinsics; - -struct Foo { - bytes: [u8; unsafe { intrinsics::size_of::() }], - //~^ ERROR cycle detected when const-evaluating + checking - x: usize, -} - -fn main() {} diff --git a/src/test/ui/issues/issue-44415.stderr b/src/test/ui/issues/issue-44415.stderr deleted file mode 100644 index 8008e53f65f..00000000000 --- a/src/test/ui/issues/issue-44415.stderr +++ /dev/null @@ -1,28 +0,0 @@ -error[E0391]: cycle detected when const-evaluating + checking `Foo::bytes::{{constant}}#0` - --> $DIR/issue-44415.rs:6:17 - | -LL | bytes: [u8; unsafe { intrinsics::size_of::() }], - | ^^^^^^ - | -note: ...which requires const-evaluating + checking `Foo::bytes::{{constant}}#0`... - --> $DIR/issue-44415.rs:6:17 - | -LL | bytes: [u8; unsafe { intrinsics::size_of::() }], - | ^^^^^^ -note: ...which requires const-evaluating `Foo::bytes::{{constant}}#0`... - --> $DIR/issue-44415.rs:6:26 - | -LL | bytes: [u8; unsafe { intrinsics::size_of::() }], - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ - = note: ...which requires computing layout of `Foo`... - = note: ...which requires normalizing `ParamEnvAnd { param_env: ParamEnv { caller_bounds: [], reveal: All, def_id: None }, value: [u8; _] }`... - = note: ...which again requires const-evaluating + checking `Foo::bytes::{{constant}}#0`, completing the cycle -note: cycle used when processing `Foo` - --> $DIR/issue-44415.rs:5:1 - | -LL | struct Foo { - | ^^^^^^^^^^ - -error: aborting due to previous error - -For more information about this error, try `rustc --explain E0391`.