lean4-htt/src/Lean/Compiler/IR/Checker.lean
2020-10-16 17:33:08 -07:00

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Text

#lang lean4
/-
Copyright (c) 2019 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Authors: Leonardo de Moura
-/
import Lean.Compiler.IR.CompilerM
import Lean.Compiler.IR.Format
namespace Lean.IR.Checker
structure CheckerContext :=
(env : Environment) (localCtx : LocalContext := {}) (decls : Array Decl)
structure CheckerState :=
(foundVars : IndexSet := {})
abbrev M := ReaderT CheckerContext (ExceptT String (StateT CheckerState Id))
def markIndex (i : Index) : M Unit := do
let s ← get
if s.foundVars.contains i then
throw s!"variable / joinpoint index {i} has already been used"
modify fun s => { s with foundVars := s.foundVars.insert i }
def markVar (x : VarId) : M Unit :=
markIndex x.idx
def markJP (j : JoinPointId) : M Unit :=
markIndex j.idx
def getDecl (c : Name) : M Decl := do
let ctx ← read
match findEnvDecl' ctx.env c ctx.decls with
| none => throw s!"unknown declaration '{c}'"
| some d => pure d
def checkVar (x : VarId) : M Unit := do
let ctx ← read
unless ctx.localCtx.isLocalVar x.idx || ctx.localCtx.isParam x.idx do
throw s!"unknown variable '{x}'"
def checkJP (j : JoinPointId) : M Unit := do
let ctx ← read
unless ctx.localCtx.isJP j.idx do
throw s!"unknown join point '{j}'"
def checkArg (a : Arg) : M Unit :=
match a with
| Arg.var x => checkVar x
| other => pure ()
def checkArgs (as : Array Arg) : M Unit :=
as.forM checkArg
@[inline] def checkEqTypes (ty₁ ty₂ : IRType) : M Unit := do
unless ty₁ == ty₂ do
throw "unexpected type"
@[inline] def checkType (ty : IRType) (p : IRType → Bool) : M Unit := do
unless p ty do
throw s!"unexpected type '{ty}'"
def checkObjType (ty : IRType) : M Unit := checkType ty IRType.isObj
def checkScalarType (ty : IRType) : M Unit := checkType ty IRType.isScalar
def getType (x : VarId) : M IRType := do
let ctx ← read
match ctx.localCtx.getType x with
| some ty => pure ty
| none => throw s!"unknown variable '{x}'"
@[inline] def checkVarType (x : VarId) (p : IRType → Bool) : M Unit := do
let ty ← getType x; checkType ty p
def checkObjVar (x : VarId) : M Unit :=
checkVarType x IRType.isObj
def checkScalarVar (x : VarId) : M Unit :=
checkVarType x IRType.isScalar
def checkFullApp (c : FunId) (ys : Array Arg) : M Unit := do
if c == `hugeFuel then
throw "the auxiliary constant `hugeFuel` cannot be used in code, it is used internally for compiling `partial` definitions"
let decl ← getDecl c
unless ys.size == decl.params.size do
throw s!"incorrect number of arguments to '{c}', {ys.size} provided, {decl.params.size} expected"
checkArgs ys
def checkPartialApp (c : FunId) (ys : Array Arg) : M Unit := do
let decl ← getDecl c
unless ys.size < decl.params.size do
throw s!"too many arguments too partial application '{c}', num. args: {ys.size}, arity: {decl.params.size}"
checkArgs ys
def checkExpr (ty : IRType) : Expr → M Unit
| Expr.pap f ys => checkPartialApp f ys *> checkObjType ty -- partial applications should always produce a closure object
| Expr.ap x ys => checkObjVar x *> checkArgs ys
| Expr.fap f ys => checkFullApp f ys
| Expr.ctor c ys => when (!ty.isStruct && !ty.isUnion && c.isRef) (checkObjType ty) *> checkArgs ys
| Expr.reset _ x => checkObjVar x *> checkObjType ty
| Expr.reuse x i u ys => checkObjVar x *> checkArgs ys *> checkObjType ty
| Expr.box xty x => checkObjType ty *> checkScalarVar x *> checkVarType x (fun t => t == xty)
| Expr.unbox x => checkScalarType ty *> checkObjVar x
| Expr.proj i x => do
let xType ← getType x;
match xType with
| IRType.object => checkObjType ty
| IRType.tobject => checkObjType ty
| IRType.struct _ tys => if h : i < tys.size then checkEqTypes (tys.get ⟨i,h⟩) ty else throw "invalid proj index"
| IRType.union _ tys => if h : i < tys.size then checkEqTypes (tys.get ⟨i,h⟩) ty else throw "invalid proj index"
| other => throw s!"unexpected IR type '{xType}'"
| Expr.uproj _ x => checkObjVar x *> checkType ty (fun t => t == IRType.usize)
| Expr.sproj _ _ x => checkObjVar x *> checkScalarType ty
| Expr.isShared x => checkObjVar x *> checkType ty (fun t => t == IRType.uint8)
| Expr.isTaggedPtr x => checkObjVar x *> checkType ty (fun t => t == IRType.uint8)
| Expr.lit (LitVal.str _) => checkObjType ty
| Expr.lit _ => pure ()
@[inline] def withParams (ps : Array Param) (k : M Unit) : M Unit := do
let ctx ← read
let localCtx ← ps.foldlM (init := ctx.localCtx) fun (ctx : LocalContext) p => do
markVar p.x
pure $ ctx.addParam p
withReader (fun _ => { ctx with localCtx := localCtx }) k
partial def checkFnBody : FnBody → M Unit
| FnBody.vdecl x t v b => do
checkExpr t v;
markVar x;
let ctx ← read
withReader (fun ctx => { ctx with localCtx := ctx.localCtx.addLocal x t v }) (checkFnBody b)
| FnBody.jdecl j ys v b => do
markJP j;
withParams ys (checkFnBody v);
let ctx ← read
withReader (fun ctx => { ctx with localCtx := ctx.localCtx.addJP j ys v }) (checkFnBody b)
| FnBody.set x _ y b => checkVar x *> checkArg y *> checkFnBody b
| FnBody.uset x _ y b => checkVar x *> checkVar y *> checkFnBody b
| FnBody.sset x _ _ y _ b => checkVar x *> checkVar y *> checkFnBody b
| FnBody.setTag x _ b => checkVar x *> checkFnBody b
| FnBody.inc x _ _ _ b => checkVar x *> checkFnBody b
| FnBody.dec x _ _ _ b => checkVar x *> checkFnBody b
| FnBody.del x b => checkVar x *> checkFnBody b
| FnBody.mdata _ b => checkFnBody b
| FnBody.jmp j ys => checkJP j *> checkArgs ys
| FnBody.ret x => checkArg x
| FnBody.case _ x _ alts => checkVar x *> alts.forM (fun alt => checkFnBody alt.body)
| FnBody.unreachable => pure ()
def checkDecl : Decl → M Unit
| Decl.fdecl f xs t b => withParams xs (checkFnBody b)
| Decl.extern f xs t _ => withParams xs (pure ())
end Checker
def checkDecl (decls : Array Decl) (decl : Decl) : CompilerM Unit := do
let env ← getEnv
match (Checker.checkDecl decl { env := env, decls := decls }).run' {} with
| Except.error msg => throw s!"IR check failed at '{decl.name}', error: {msg}"
| other => pure ()
def checkDecls (decls : Array Decl) : CompilerM Unit :=
decls.forM (checkDecl decls)
end IR
end Lean