lean4-htt/library/init/Lean/extern.lean
2019-03-21 15:06:44 -07:00

99 lines
3.6 KiB
Text
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/-
Copyright (c) 2019 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Authors: Leonardo de Moura
-/
prelude
import init.lean.expr init.data.option.basic
namespace Lean
inductive ExternEntry
| adhoc (backend : Name)
| inline (backend : Name) (pattern : String)
| standard (backend : Name) (fn : String)
| foreign (backend : Name) (fn : String)
@[export Lean.mkAdhocExtEntryCore] def mkAdhocExtEntry := ExternEntry.adhoc
@[export Lean.mkInlineExtEntryCore] def mkInlineExtEntry := ExternEntry.inline
@[export Lean.mkStdExtEntryCore] def mkStdExtEntry := ExternEntry.standard
@[export Lean.mkForeignExtEntryCore] def mkForeignExtEntry := ExternEntry.foreign
/-
- `@[extern]`
encoding: ```.entries = [adhoc `all]```
- `@[extern "level_hash"]`
encoding: ```.entries = [standard `all "levelHash"]```
- `@[extern cpp "lean::string_size" llvm "lean_str_size"]`
encoding: ```.entries = [standard `cpp "lean::string_size", standard `llvm "leanStrSize"]```
- `@[extern cpp inline "#1 + #2"]`
encoding: ```.entries = [inline `cpp "#1 + #2"]```
- `@[extern cpp "foo" llvm adhoc]`
encoding: ```.entries = [standard `cpp "foo", adhoc `llvm]```
- `@[extern 2 cpp "io_prim_println"]`
encoding: ```.arity = 2, .entries = [standard `cpp "ioPrimPrintln"]```
-/
structure ExternAttrData :=
(arity : Option Nat := none)
(entries : List ExternEntry)
@[export Lean.mkExternAttrDataCore] def mkExternAttrData := ExternAttrData.mk
private def parseOptNum : Nat → String.Iterator → Nat → String.Iterator × Nat
| 0 it r := (it, r)
| (n+1) it r :=
if !it.hasNext then (it, r)
else
let c := it.curr in
if '0' <= c && c <= '9'
then parseOptNum n it.next (r*10 + (c.toNat - '0'.toNat))
else (it, r)
def expandExternPatternAux (args : List String) : Nat → String.Iterator → String → String
| 0 it r := r
| (i+1) it r :=
if ¬ it.hasNext then r
else let c := it.curr in
if c ≠ '#' then expandExternPatternAux i it.next (r.push c)
else
let it := it.next in
let (it, j) := parseOptNum it.remaining it 0 in
let j := j-1 in
expandExternPatternAux i it (r ++ (args.nth j).getOrElse "")
@[export Lean.expandExternPatternCore]
def expandExternPattern (pattern : String) (args : List String) : String :=
expandExternPatternAux args pattern.length pattern.mkIterator ""
def mkSimpleFnCall (fn : String) (args : List String) : String :=
fn ++ "(" ++ ((args.intersperse ", ").foldl (++) "") ++ ")"
def expandExternEntry : ExternEntry → List String → Option String
| (ExternEntry.adhoc _) args := none -- backend must expand it
| (ExternEntry.standard _ fn) args := some (mkSimpleFnCall fn args)
| (ExternEntry.inline _ pat) args := some (expandExternPattern pat args)
| (ExternEntry.foreign _ fn) args := some (mkSimpleFnCall fn args)
def ExternEntry.backend : ExternEntry → Name
| (ExternEntry.adhoc n) := n
| (ExternEntry.inline n _) := n
| (ExternEntry.standard n _) := n
| (ExternEntry.foreign n _) := n
def getExternEntryForAux (backend : Name) : List ExternEntry → Option ExternEntry
| [] := none
| (e::es) :=
if e.backend = `all then some e
else if e.backend = backend then some e
else getExternEntryForAux es
@[export Lean.getExternEntryForCore]
def getExternEntryFor (d : ExternAttrData) (backend : Name) : Option ExternEntry :=
getExternEntryForAux backend d.entries
@[export Lean.mkExternCallCore]
def mkExternCall (d : ExternAttrData) (backend : Name) (args : List String) : Option String :=
do e ← getExternEntryFor d backend,
expandExternEntry e args
end Lean