(*
 * Copyright (c) 2015 - present Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 *)
{
  open Lexing
  open LParser

  exception LexingError of string
}

let space = [' ' '\t']
let newline = '\n'
let comment = ';' [^ '\n']*

let nonzero_digit = ['1'-'9']
let digit = ['0'-'9']
let pos_int = nonzero_digit digit*
let intlit = '-'? digit+

let lower = ['a'-'z']
let upper = ['A'-'Z']
let id_special_char = ['-' '$' '.' '_']
let id_char = lower | upper | id_special_char
let id = id_char (id_char | digit)*

rule token = parse
  | space | comment  { token lexbuf }
  | newline  { token lexbuf }

  (* keywords *)
  | "define"  { DEFINE }

  (* delimiters *)
  | ','  { COMMA }
  | '('  { LPAREN }
  | ')'  { RPAREN }
  | '{'  { LBRACE }
  | '}'  { RBRACE }
  | '<'  { LANGLE }
  | '>'  { RANGLE }
  | '['  { LSQBRACK }
  | ']'  { RSQBRACK }
  (* symbols *)
  | '='  { EQUALS }
  | '*'  { STAR }
  | ['x' 'X']  { X }

  (* TYPES *)
  | "void"  { VOID }
  | "i1" { BIT (* INT 1 *) }
  | 'i' (pos_int as width)  { INT (int_of_string width) }
  | "half"  { HALF }
  | "float"  { FLOAT }
  | "double"  { DOUBLE }
  | "fp128"  { FP128 }
  | "x86_fp80"  { X86_FP80 }
  | "ppc_fp128"  { PPC_FP128 }
  | "x86_mmx"  { X86_MMX }
  | "label"  { LABEL }
  | "metadata"  { METADATA }

  | pos_int as size  { SIZE (int_of_string size) }
  (* CONSTANTS *)
  | "true"  { CONSTINT 1 }
  | "false"  { CONSTINT 0 }
  | intlit as i  { CONSTINT (int_of_string i) }
  (* floating point constants *)
  | "null"  { NULL }

  (* INSTRUCTIONS *)
  (* terminator instructions *)
  | "ret"  { RET }
  | "br"  { BR }
  | "switch"  { SWITCH }
  | "indirectbr"  { INDIRECTBR }
  | "invoke"  { INVOKE }
  | "resume"  { RESUME }
  | "unreachable"  { UNREACHABLE }
  (* binary operations *)
  | "add"  { ADD }
  | "fadd"  { FADD }
  | "sub"  { SUB }
  | "fsub"  { FSUB }
  | "mul"  { MUL }
  | "fmul"  { FMUL }
  | "udiv"  { UDIV }
  | "sdiv"  { SDIV }
  | "fdiv"  { FDIV }
  | "urem"  { UREM }
  | "srem"  { SREM }
  | "frem"  { FREM }
  (* arithmetic options *)
  | "nuw"  { NUW }
  | "nsw"  { NSW }
  | "exact"  { EXACT }
  (* floating point options *)
  | "nnan"  { NNAN }
  | "ninf"  { NINF }
  | "nsz"  { NSZ }
  | "arcp"  { ARCP }
  | "fast"  { FAST }
  (* bitwise binary operations *)
  | "shl" { SHL }
  | "lshr"  { LSHR }
  | "ashr"  { ASHR }
  | "and" { AND }
  | "or"  { OR }
  | "xor" { XOR }
  (* vector operations *)
  | "extractelement"  { EXTRACTELEMENT }
  | "insertelement" { INSERTELEMENT }
  | "shufflevector" { SHUFFLEVECTOR }
  (* aggregate operations *)
  | "extractvalue"  { EXTRACTVALUE }
  | "insertvalue" { INSERTVALUE }
  (* memory access and addressing operations *)
  | "alloca"  { ALLOCA }
  | "load"  { LOAD }
  | "store" { STORE }
  | "fence" { FENCE }
  | "cmpxchg" { CMPXCHG }
  | "atomicrmw" { ATOMICRMW }
  | "getelementptr" { GETELEMENTPTR }
  (* conversion operations *)
  | "trunc" { TRUNC } (* e.g. trunc ... to ... *)
  | "zext"  { ZEXT }
  | "sext"  { SEXT }
  | "fptrunc" { FPTRUNC }
  | "fpext" { FPEXT }
  | "fptoui"  { FPTOUI }
  | "fptosi"  { FPTOSI }
  | "uitofp"  { UITOFP }
  | "sitofp"  { SITOFP }
  | "ptrtoint"  { PTRTOINT }
  | "inttoptr"  { INTTOPTR }
  | "bitcast" { BITCAST }
  | "addrspacecast" { ADDRSPACECAST }
  | "to"  { TO } (* all conversion operations include this keyword *)
  (* other operations *)
  | "icmp"  { ICMP }
  | "fcmp"  { FCMP }
  | "phi" { PHI }
  | "select"  { SELECT }
  | "call"  { CALL }
  | "va_arg"  { VA_ARG }
  | "landingpad"  { LANDINGPAD }

  (* identifiers - make this complete *)
  | '@'  { AT }
  | '%'  { PERCENT }
  | id as str  { IDENT str }

  | eof  { EOF }