fun ($a, $b) { ... }

[p5sagit/Devel-Declare.git] / Declare.xs

#define PERL_IN_TOKE_C
#define PERL_CORE
#define PERL_NO_GET_CONTEXT
#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"
#undef printf
#include "stolen_chunk_of_toke.c"
#include <stdio.h>
#include <string.h>

#define DD_DEBUG 0

#define DD_HANDLE_NAME 1
#define DD_HANDLE_PROTO 2

#ifdef DD_DEBUG
#define DD_DEBUG_S printf("Buffer: %s\n", s);
#else
#define DD_DEBUG_S
#endif

#define LEX_NORMAL    10
#define LEX_INTERPNORMAL   9

/* placeholders for PL_check entries we wrap */

STATIC OP *(*dd_old_ck_rv2cv)(pTHX_ OP *op);
STATIC OP *(*dd_old_ck_nextstate)(pTHX_ OP *op);

/* flag to trigger removal of temporary declaree sub */

static int in_declare = 0;

/* replacement PL_check rv2cv entry */

STATIC OP *dd_ck_rv2cv(pTHX_ OP *o) {
  OP* kid;
  char* s;
  char* save_s;
  char tmpbuf[sizeof PL_tokenbuf];
  char found_name[sizeof PL_tokenbuf];
  char* found_proto = NULL;
  STRLEN len = 0;
  HV *stash;
  HV* is_declarator;
  SV** is_declarator_pack_ref;
  HV* is_declarator_pack_hash;
  SV** is_declarator_flag_ref;
  int dd_flags;
  char* cb_args[5];

  o = dd_old_ck_rv2cv(aTHX_ o); /* let the original do its job */

  if (in_declare) {
    cb_args[0] = NULL;
    call_argv("Devel::Declare::done_declare", G_VOID|G_DISCARD, cb_args);
    in_declare--;
    return o;
  }

  kid = cUNOPo->op_first;

  if (kid->op_type != OP_GV) /* not a GV so ignore */
    return o;

  if (PL_lex_state != LEX_NORMAL && PL_lex_state != LEX_INTERPNORMAL)
    return o; /* not lexing? */

  stash = GvSTASH(kGVOP_gv);

#ifdef DD_DEBUG
  printf("Checking GV %s -> %s\n", HvNAME(stash), GvNAME(kGVOP_gv));
#endif

  is_declarator = get_hv("Devel::Declare::declarators", FALSE);

  if (!is_declarator)
    return o;

  is_declarator_pack_ref = hv_fetch(is_declarator, HvNAME(stash),
                             strlen(HvNAME(stash)), FALSE);

  if (!is_declarator_pack_ref || !SvROK(*is_declarator_pack_ref))
    return o; /* not a hashref */

  is_declarator_pack_hash = (HV*) SvRV(*is_declarator_pack_ref);

  is_declarator_flag_ref = hv_fetch(is_declarator_pack_hash, GvNAME(kGVOP_gv),
                                strlen(GvNAME(kGVOP_gv)), FALSE);

  /* requires SvIOK as well as TRUE since flags not being an int is useless */

  if (!is_declarator_flag_ref
        || !SvIOK(*is_declarator_flag_ref) 
        || !SvTRUE(*is_declarator_flag_ref))
    return o;

  dd_flags = SvIVX(*is_declarator_flag_ref);

#ifdef DD_DEBUG
  printf("dd_flags are: %i\n", dd_flags);
#endif

  s = PL_bufptr; /* copy the current buffer pointer */

  DD_DEBUG_S

#ifdef DD_DEBUG
  printf("PL_tokenbuf: %s\n", PL_tokenbuf);
#endif

  /*
   *   buffer will be at the beginning of the declarator, -unless- the
   *   declarator is at EOL in which case it'll be the next useful line
   *   so we don't short-circuit out if we don't find the declarator
   */

  while (s < PL_bufend && isSPACE(*s)) s++;
  if (memEQ(s, PL_tokenbuf, strlen(PL_tokenbuf)))
    s += strlen(PL_tokenbuf);

  DD_DEBUG_S

  if (dd_flags & DD_HANDLE_NAME) {

    /* find next word */

    s = skipspace(s);

    DD_DEBUG_S

    /* 0 in arg 4 is allow_package - not trying that yet :) */

    s = scan_word(s, tmpbuf, sizeof tmpbuf, 0, &len);

    DD_DEBUG_S

    if (len) {
      strcpy(found_name, tmpbuf);
#ifdef DD_DEBUG
      printf("Found %s\n", found_name);
#endif
    }
  }

  if (dd_flags & DD_HANDLE_PROTO) {

    s = skipspace(s);

    if (*s == '(') { /* found a prototype-ish thing */
      save_s = s;
      s = scan_str(s, FALSE, FALSE); /* no keep_quoted, no keep_delims */
      if (SvPOK(PL_lex_stuff)) {
#ifdef DD_DEBUG
        printf("Found proto %s\n", SvPVX(PL_lex_stuff));
#endif
        found_proto = SvPVX(PL_lex_stuff);
        *save_s++ = '=';
        *save_s++ = 'X';
        while (save_s < s) {
          *save_s++ = ' ';
        }
#ifdef DD_DEBUG
        printf("Curbuf %s\n", PL_bufptr);
#endif
      }
    }
  }

  if (len || found_proto) {
    if (!len)
      found_name[0] = 0;
#ifdef DD_DEBUG
  printf("Calling init_declare");
#endif
    cb_args[0] = HvNAME(stash);
    cb_args[1] = GvNAME(kGVOP_gv);
    cb_args[2] = found_name;
    cb_args[3] = found_proto;
    cb_args[4] = NULL;
    call_argv("Devel::Declare::init_declare", G_VOID|G_DISCARD, cb_args);
    if (len && found_proto)
      in_declare = 2;
    else
      in_declare = 1;
    if (found_proto)
      PL_lex_stuff = Nullsv;
  }

  return o;
}

static int initialized = 0;

MODULE = Devel::Declare  PACKAGE = Devel::Declare

PROTOTYPES: DISABLE

void
setup()
  CODE:
  if (!initialized++) {
    dd_old_ck_rv2cv = PL_check[OP_RV2CV];
    PL_check[OP_RV2CV] = dd_ck_rv2cv;
  }

void
teardown()
  CODE:
  /* ensure we only uninit when number of teardown calls matches 
     number of setup calls */
  if (initialized && !--initialized) {
    PL_check[OP_RV2CV] = dd_old_ck_rv2cv;
  }