/* pkl-lex.l - Lexer for Poke.  */

/* Copyright (C) 2019, 2020, 2021, 2022, 2023, 2024, 2025, 2026 Jose E.
 * Marchesi */

/* This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/* Automake needs this.  */
%option outfile="lex.yy.c"
%option prefix="pkl_tab_"
%option warn nodefault
%option pointer
%option noyywrap
%option reentrant
%option bison-bridge
%option header-file="pkl-lex.h"
%option bison-locations
%option noinput
%option nounput
   /* %option yylineno */
%option extra-type="struct pkl_parser *"

%top {
   /* This code goes at the "top" of the generated file.  */
   #include <config.h>
}

%{
#include <string.h>
#include <unistd.h>
#include <ctype.h>
#include <assert.h>
#include <stdlib.h>
#include <setjmp.h>

#include "pk-utils.h"
#include "pkl.h"
#include "pkl-ast.h"
#include "pkl-env.h"
#include "pkl-diag.h"
#include "pkl-parser.h"
#define YYSTYPE PKL_TAB_STYPE
#define YYLTYPE pkl_ast_loc
#define YYDEBUG 1
#include <pkl-tab.h>

#define RESTORE_LOC                             \
  do                                            \
    {                                           \
      yylloc = &yyextra->prev_loc;              \
    }                                           \
  while (0)

#define YY_FATAL_ERROR(msg)                             \
  do                                                    \
    {                                                   \
     YYLTYPE *loc = yyget_lloc (yyscanner);             \
     YY_EXTRA_TYPE extra = yyget_extra (yyscanner);     \
     pkl_error (extra->compiler, extra->ast, *loc, "%s",  \
                msg);                                     \
     longjmp (extra->toplevel, 1);                      \
     /* kludge to avoid compiler warning */             \
     void *x = yy_fatal_error; x = x;                   \
    }                                                   \
  while (0)

#define YY_USER_ACTION                                  \
  do                                                    \
    {                                                   \
     int i;                                             \
                                                        \
     /* Save a copy of the current location */          \
     /* so we can restore it when we call   */          \
     /* REJECT. */                                      \
     yyextra->prev_loc = *yylloc;                       \
                                                        \
     yylloc->first_line = yylloc->last_line;            \
     yylloc->first_column = yylloc->last_column;        \
                                                        \
     for (i = 0; yytext[i] != '\0'; i++)                \
       {                                                \
         if (yytext[i] == '\n')                         \
           {                                            \
             yylloc->last_line++;                       \
             yylloc->last_column = 1;                   \
           }                                            \
         else                                           \
           yylloc->last_column++;                       \
       }                                                \
                                                        \
     yyextra->nchars += yyleng;                         \
    } while (0);

/* Note that the following function assumes that STR is a pointer of a
   string that satisfies the regexp
   ({HEXCST}|{BINCST}|{OCTCST}|{DECCST}) */

int
pkl_lex_get_base (const char *str, int *offset)
{
 int base = 10;
 *offset = 0;

 if (str[0] == '0')
  {
    if (str[1] == 'x' || str[1] == 'X')
    {
      base = 16;
      *offset = 2;
    }
    else if ((str[1] == 'b' || str[1] == 'B')
             && (str[2] != '\0'))
    {
      /* Note the above check for \0 is to distinguish these two
         cases: 0[bB][0-1]+ and 0[bB]  */
      base = 2;
      *offset = 2;
    }
    else if (str[1] == 'o' || str[1] == 'O')
    {
      base = 8;
      *offset = 2;
    }
  }
  return base;
}

/* Parse the suffix for integer literals.

   If there's no [uU] chars, set *SIGNED_P to 0, otherwise 1.
   If there's no [tTnNbBhHlL] chars, set *WIDTH to 0, otherwise set
   *WIDTH to corresponding width.  */

void
parse_integer_literal_suffix (int *signed_p, int *width, const char *end)
{
  *signed_p = 1;
  if (*end == 'u' || *end == 'U'
      || (*end != '\0' && (*(end + 1) == 'u' || *(end + 1) == 'U')))
    *signed_p = 0;
  else if (*end == 't' || *end == 'T'
      || ((*end != '\0') && (*(end + 1) == 't' || *(end + 1) == 'T')))
    *signed_p = 0;

  *width = 0;
  if (*end == 'l' || *end == 'L'
      || ((*end != '\0') && (*(end + 1) == 'l' || *(end + 1) == 'L')))
    *width = 64;
  else  if (*end == 'h' || *end == 'H'
      || ((*end != '\0') && (*(end + 1) == 'h' || *(end + 1) == 'H')))
    *width = 16;
  else  if (*end == 'b' || *end == 'B'
      || ((*end != '\0') && (*(end + 1) == 'b' || *(end + 1) == 'B')))
    *width = 8;
  else if (*end == 'n' || *end == 'N'
      || ((*end != '\0') && (*(end + 1) == 'n' || *(end + 1) == 'N')))
    *width = 4;
  else if (*end == 't' || *end == 'T'
      || ((*end != '\0') && (*(end + 1) == 't' || *(end + 1) == 'T')))
    *width = 1;
}

/* If the width is not already known (e.g., based on the suffix),
   the type of the integer constant is the smallest signed or unsigned
   integer capable of holding it, starting with 32 bits, in steps of
   power of two and up to 64 bits.  But note these are positive values!  */

static int
integer_literal_width (uint64_t value, int signed_p)
{
  if (value > 0x0000000080000000 && value <= 0x00000000ffffffff)
    return signed_p ? 64 : 32;
  else if (value & 0xffffffff00000000)
    return 64;
  return 32;
}

/* Handle overflow for integer literals:
     - Signed integer: check for overflow (of course only for positives).
     - Unsigned integers: truncate the VALUE to fit into the WIDTH.
   If the bit kidth of VALUE is not known, choose a proper width.

   Return 1 on detection of overflow, otherwise 0.  */

static int
integer_literal_overflow_handling (uint64_t *value, int signed_p, int width)
{
  /* Handle overflow in signed integers.  Note that the lexer only
     sees positive signed integers.  */
  if (signed_p && *value >= ((uint64_t)1 << (width - 1)))
    return 1;

  /* Handle truncation in unsigned integers.  */
  if (!signed_p && width < 64)
   *value &= ((uint64_t) 1 << width) - 1;

  return 0;
}

static char *
build_overflow_error_msg (uint64_t value, int width)
{
  char *msg = NULL;
  const char *suffix = (width == 64 ? "L"
                        : width == 8 ? "B"
                        : width == 16 ? "H"
                        : width == 4 ? "N"
                        : "");

  asprintf (&msg,
            "signed overflow\ntry: %" PRIu64 "U%s as int<%d>",
            value, suffix, width);
  return msg;
}

%}

NEWLINE            (\r\n)|\n
BLANK              [ \t]
LETTER             [a-zA-Z]
FIELD_NAME         {LETTER}[a-zA-Z0-9_]*
CHAR                   '(.|\\[ntr\\]|\\[0-7]|\\[0-7][0-7]|\\[0-7][0-7][0-7])'
STRING             \"([^"\\]|\\(.|\n))*\"
HEXCST                   0[xX][0-9a-fA-F][0-9a-fA-F_]*
BINCST                   0[bB][01][01_]*
OCTCST             0[oO][0-7][0-7_]*
DECCST             [0-9][0-9_]*
IS                 ((u|U)|(u|U)?(l|L|b|B|h|H|n|N)|(l|L|b|B|h|H|n|N)(u|U)|(t|T))

L [a-zA-Z_]
D [0-9]
A $
S ::
LT <
GT >
NOT_GT [^>]

%x C_COMMENT
%x SHEBANG_COMMENT

%%

%{
  /* Handle the support for multiple parsers.  */

  if (yyextra->start_token)
  {
    int t = yyextra->start_token;
    yyextra->start_token = 0;
    return t;
  }
%}

{NEWLINE}        { /* Ignore newlines.  */  }
{BLANK}                { /* Ignore whitespace.  */ }
\f                { /* Ignore form feed ^L characters.  */ }

"/*" { BEGIN(C_COMMENT); }
<C_COMMENT>"*/" { BEGIN(INITIAL); }
<C_COMMENT>.    {  }
<C_COMMENT>\n   {  }

"#!" { BEGIN(SHEBANG_COMMENT); }
<SHEBANG_COMMENT>"!#" { BEGIN(INITIAL); }
<SHEBANG_COMMENT>.    {  }
<SHEBANG_COMMENT>\n   {  }

"//"[^\n]*        { /* Partial-line comment.  */ }

"__LINE__"        {
  pkl_ast_node type
    = pkl_ast_make_integral_type (yyextra->ast, 64, 0);
  yylval->ast = pkl_ast_make_integer (yyextra->ast,
                                      yylloc->first_line);
  PKL_AST_TYPE (yylval->ast) = ASTREF (type);

  return INTEGER;
}

"__FILE__"        {
  pkl_ast_node type
    = pkl_ast_make_string_type (yyextra->ast);

  yylval->ast = pkl_ast_make_string (yyextra->ast,
                                     yyextra->filename
                                     ? yyextra->filename
                                     : "<stdin>");
  PKL_AST_TYPE (yylval->ast) = ASTREF (type);
  return STR;
 }

  /* BEGINNING OF KEYWORDS */
"asm"           { return ASM; }
"pinned"        { return PINNED; }
"struct"        { return STRUCT; }
"union"         { return UNION; }
"else"          { return ELSE; }
"while"         { return WHILE; }
"until"         { return UNTIL; }
"for"           { return FOR; }
"in"            { return IN; }
"where"         { return WHERE; }
"if"            { return IF; }
"sizeof"        { return SIZEOF; }
"typeof"        { return TYPEOF; }
"apush"         { return APUSH; }
"apop"          { return APOP; }
"fun"           { return DEFUN; }
"method"        { return METHOD; }
"type"          { return DEFTYPE; }
"var"           { return DEFVAR; }
"unit"          { return DEFUNIT; }
"break"         { return BREAK; }
"continue"      { return CONTINUE; }
"return"        { return RETURN; }
"string"        { return STRING; }
"as"            { return AS; }
"try"           { return TRY; }
"catch"         { return CATCH; }
"raise"         { return RAISE; }
"void"          { return VOID; }
"any"           { return ANY; }
"print"         { return PRINT; }
"printf"        { return PRINTF; }
"isa"           { return ISA; }
"unmap"         { return UNMAP; }
"remap"         { return REMAP; }
"big"           { return BIG; }
"little"        { return LITTLE; }
"load"          { return LOAD; }
"lambda"        { return LAMBDA; }
"assert"        { return ASSERT; }
"format"        { return FORMAT; }
"enum"          { return ENUM; }
"computed"      { return COMPUTED; }
"immutable"     { return IMMUTABLE; }
  /* END OF KEYWORDS */

"uint<"         { return UINTCONSTR; }
"int<"          { return INTCONSTR; }
"offset<"       { return OFFSETCONSTR; }

"..."           { return THREEDOTS; }
"+:"            { return RANGEA; }

"**="               { return POWA; }
"*="                { return MULA; }
"/="                { return DIVA; }
"%="                { return MODA; }
"+="                { return ADDA; }
"-="                { return SUBA; }
"<<.="              { return SLA; }
".>>="              { return SRA; }
"&="                { return BANDA; }
"|="                { return IORA; }
"^="                { return XORA; }
":::"               { return BCONC; }
"?!"                { return EXCOND; }
"||"                { return OR; }
"&&"                { return AND; }
"=>"                { return IMPL; }
"=="                { return EQ; }
"!="                { return NE; }
"<="                { return LE; }
">="                { return GE; }
"<<."                { return SL; }
".>>"                { return SR; }
"++"                { return INC; }
"--"                { return DEC; }
"->"                { return IND; }

"]"{IS} {
  int signed_p, width;

  parse_integer_literal_suffix (&signed_p, &width, &yytext[1]);
  if (!width)
    width = 32;
  yylval->ast = pkl_ast_make_integral_type (yyextra->ast, width, signed_p);
  yylval->ast = ASTREF (yylval->ast);
  return ARRSUF;
}

"["                { return '['; }
"]"                { return ']'; }
"("                { return '('; }
")"                { return ')'; }
"{"                { return '{'; }
"}"                { return '}'; }
","                { return ','; }
"="                { return '='; }
"?"                { return '?'; }
";"                { return ';'; }
":"                { return ':'; }
"|"                { return '|'; }
"^"                { return '^'; }
"&"                { return '&'; }
"<"                { return '<'; }
">"                { return '>'; }
"+"                { return '+'; }
"-"                { return '-'; }
"**"                { return POW; }
"*"                { return '*'; }
"/^"                { return CEILDIV; }
"/"                { return '/'; }
"%"                { return '%'; }
"!"                { return '!'; }
"~"                { return '~'; }
"."                { return '.'; }
"@!"               { return NSMAP; }
"@"                { return '@'; }

({A}({L}|{D})({L}|{D}|({S}({L}|{D})))*)|({A}{LT}{NOT_GT}*{GT}) {
  char *errmsg;
  pkl_alien_token_handler_fn cb = NULL;
  pkl_alien_dtoken_handler_fn dcb = NULL;

  if (yytext[1] == '<')
    dcb = pkl_alien_dtoken_fn (yyextra->compiler);
  else
    cb = pkl_alien_token_fn (yyextra->compiler);

  if (pkl_lexical_cuckolding_p (yyextra->compiler)
      && (cb != NULL || dcb != NULL))
    {
      struct pkl_alien_token *token
        = (cb != NULL
           ? (*cb) (yytext + 1, &errmsg)
           : (*dcb) (yytext[1], yytext + 1, &errmsg));

      if (token == NULL)
        {
          /* Error from alien handler.  */
          yyextra->alien_errmsg = errmsg;
          return ALIEN;
          break;
        }

      switch (token->kind)
        {
        case PKL_ALIEN_TOKEN_IDENTIFIER:
          {
            char *id = token->value.identifier;
            yylval->ast = pkl_ast_make_identifier (yyextra->ast,
                                                   id);
            free (id);
            return IDENTIFIER;
            break;
          }
        case PKL_ALIEN_TOKEN_STRING:
          {
            pkl_ast_node type = pkl_ast_make_string_type (yyextra->ast);

            yylval->ast
              = pkl_ast_make_string (yyextra->ast, token->value.string.str);
            PKL_AST_TYPE (yylval->ast) = ASTREF (type);

            return STR;
            break;
          }
        case PKL_ALIEN_TOKEN_INTEGER:
          {
            uint64_t value = token->value.integer.magnitude;
            int signed_p = token->value.integer.signed_p;
            int width = token->value.integer.width;
            pkl_ast_node type;

            if (width == 0)
              width = integer_literal_width (value, signed_p);
            if (integer_literal_overflow_handling (&value, signed_p, width))
              {
                yylval->exception_msg = build_overflow_error_msg (value, width);
                return LEXER_EXCEPTION;
              }

            type = pkl_ast_make_integral_type (yyextra->ast, width, signed_p);

            yylval->ast = pkl_ast_make_integer (yyextra->ast, value);
            PKL_AST_TYPE (yylval->ast) = ASTREF (type);

            return INTEGER;
            break;
          }
        case PKL_ALIEN_TOKEN_OFFSET:
          {
            uint64_t value = token->value.offset.magnitude;
            int signed_p = token->value.offset.signed_p;
            int width = token->value.offset.width;
            pkl_ast_node unit, magnitude, magnitude_type, offset_type, unit_type;

            if (width == 0)
              width = integer_literal_width (value, signed_p);
            if (integer_literal_overflow_handling (&value, signed_p, width))
              {
                yylval->exception_msg = build_overflow_error_msg (value, width);
                return LEXER_EXCEPTION;
              }

            /* Build the offset magnitude.  */
            magnitude_type = pkl_ast_make_integral_type (yyextra->ast, width, signed_p);
            magnitude = pkl_ast_make_integer (yyextra->ast, value);
            PKL_AST_TYPE (magnitude) = ASTREF (magnitude_type);

            /* Build the offset unit.  */
            unit_type = pkl_ast_make_integral_type (yyextra->ast, 64, 0);
            unit = pkl_ast_make_integer (yyextra->ast, token->value.offset.unit);
            PKL_AST_TYPE (unit) = ASTREF (unit_type);

            /* Build the offset value itself.  */
            offset_type = pkl_ast_make_offset_type (yyextra->ast,
                                                    magnitude_type,
                                                    unit, NULL /* ref_type */);
            yylval->ast = pkl_ast_make_offset (yyextra->ast,
                                               magnitude, unit);
            PKL_AST_TYPE (yylval->ast) = ASTREF (offset_type);
            return OFFSET;
            break;
          }
        default:
          PK_UNREACHABLE ();
          break;
        }
    }

  /* Lexical cuckolding is not enabled.  */
  yylloc->last_column -= strlen (yytext);
  RESTORE_LOC;
  REJECT;
}

'{L}({L}|{D})* {
  yylval->ast = pkl_ast_make_identifier (yyextra->ast, yytext + 1);
  return ATTR;
}

#({HEXCST}|{BINCST}|{OCTCST}|{DECCST}) {
  char *end;
  int base, offset;
  uint64_t value;
  pkl_ast_node type
     = pkl_ast_make_integral_type (yyextra->ast, 64, 0);

  base = pkl_lex_get_base (yytext + 1, &offset);
  value = strtoll (yytext + 1 + offset, &end, base);
  yylval->ast = pkl_ast_make_integer (yyextra->ast, value);
  PKL_AST_TYPE (yylval->ast) = ASTREF (type);

  return UNIT;
}

#{L}({L}|{D})* {
   pkl_ast_node decl
      = pkl_env_lookup (yyextra->env, PKL_ENV_NS_UNITS,
                        yytext + 1, NULL, NULL);

   if (decl)
     yylval->ast = PKL_AST_DECL_INITIAL (decl);
   else
     {
       decl = pkl_env_lookup (yyextra->env, PKL_ENV_NS_MAIN,
                              yytext + 1, NULL, NULL);

       if (decl && PKL_AST_DECL_KIND (decl) == PKL_AST_DECL_KIND_TYPE)
         yylval->ast = PKL_AST_DECL_INITIAL (decl);
       else
         yylval->ast = NULL;
     }

   return UNIT;
}

{L}({L}|{D})* {
   pkl_ast_node decl
     = pkl_env_lookup (yyextra->env, PKL_ENV_NS_MAIN,
                       yytext, NULL, NULL);

   yylval->ast = pkl_ast_make_identifier (yyextra->ast, yytext);

   if (decl && PKL_AST_DECL_KIND (decl) == PKL_AST_DECL_KIND_TYPE)
     return TYPENAME;
   else
     return IDENTIFIER;
}

({HEXCST}|{BINCST}|{OCTCST}|{DECCST}){IS}? {
  uint64_t value;
  int base, offset, signed_p, width;
  char *p, *end;
  pkl_ast_node type;

  /* First of all, strip any '_' character from yytext.  */
  for (p = yytext; *p != '\0'; p++)
  {
    char *tmp;

    while (*p == '_')
     for (tmp = p; *tmp != '\0'; tmp++)
       *tmp = *(tmp + 1);
  }

  base = pkl_lex_get_base (yytext, &offset);

  /* strtoull can fail here only in case of overflow.  */
  errno = 0;
  value = strtoull (yytext + offset, &end, base);
  if (value == ULLONG_MAX && errno == ERANGE)
    {
      yylval->exception_msg = strdup ("integer literal is too big");
      return LEXER_EXCEPTION;
    }

  parse_integer_literal_suffix (&signed_p, &width, end);

  if (width == 0)
    width = integer_literal_width (value, signed_p);
  if (integer_literal_overflow_handling (&value, signed_p, width))
    {
      yylval->exception_msg = build_overflow_error_msg (value, width);
      return LEXER_EXCEPTION;
    }

  type = pkl_ast_make_integral_type (yyextra->ast, width, signed_p);

  yylval->ast = pkl_ast_make_integer (yyextra->ast, value);
  PKL_AST_TYPE (yylval->ast) = ASTREF (type);

  return INTEGER;
}

{CHAR} {
   uint8_t value;
   pkl_ast_node type;

   if (yytext[1] == '\\')
    {
      if (yytext[2] >= '0' && yytext[2] <= '9')
        {
          char *end;
          uint64_t val64;

          /* strtoll can't fail in this context.  */
          val64 = strtoll (yytext + 2, &end, 8);
          value = (uint8_t) val64;
        }
      else
        switch (yytext[2])
          {
          case 'n':
            value = '\n';
            break;
          case 't':
            value = '\t';
            break;
          case 'r':
            value = '\r';
            break;
          case '\\':
            value = '\\';
            break;
          default:
            /* To avoid compiler warnings.  */
            value = 0;
            break;
          }
    }
   else
     value = yytext[1];

   type = pkl_ast_make_integral_type (yyextra->ast, 8, 0);
   PKL_AST_TYPE_COMPLETE (type) = PKL_AST_TYPE_COMPLETE_YES;

   yylval->ast = pkl_ast_make_integer (yyextra->ast, value);
   PKL_AST_TYPE (yylval->ast) = ASTREF (type);

   return CHAR;
}

{STRING} {
   pkl_ast_node type;

   /* Strip the quoting characters */
   yytext[strlen (yytext) - 1] = 0;

   type = pkl_ast_make_string_type (yyextra->ast);

   yylval->ast = pkl_ast_make_string (yyextra->ast, yytext + 1);
   PKL_AST_TYPE (yylval->ast) = ASTREF (type);

   return STR;
}

. { return ERR; }

%%

/*
Local variables:
mode:c
End:
*/
