File Coverage

lib/Class/Plain.xs

Criterion	Covered	Total	%
statement	159	204	77.9
branch	72	132	54.5
condition			n/a
subroutine			n/a
pod			n/a
total	231	336	68.7

#define PERL_NO_GET_CONTEXT

#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"

#include "XSParseKeyword.h"

#include "XSParseSublike.h"

#include "perl-backcompat.c.inc"
#include "sv_setrv.c.inc"

#include "perl-additions.c.inc"
#include "lexer-additions.c.inc"
#include "forbid_outofblock_ops.c.inc"
#include "force_list_keeping_pushmark.c.inc"
#include "optree-additions.c.inc"
#include "newOP_CUSTOM.c.inc"

#include "class_plain_parser.h"
#include "class_plain_class.h"
#include "class_plain_field.h"
#include "class_plain_method.h"

/**********************************
 * Class and Field Implementation *
 **********************************/

enum {
  METATYPE_ROLE = 1,
};

static XOP xop_methstart;
static OP* pp_methstart(pTHX) {
  SV* self = av_shift(GvAV(PL_defgv));

  if(!SvROK(self) || !SvOBJECT(SvRV(self)))
    croak("Cannot invoke method on a non-instance");

  save_clearsv(&PAD_SVl(1));
  sv_setsv(PAD_SVl(1), self);

  return PL_op->op_next;
}

OP* ClassPlain_newMETHSTARTOP(pTHX_ U32 flags)
{
  OP* op = newOP_CUSTOM(&pp_methstart, flags);
  op->op_private = (U8)(flags >> 8);
  return op;
}

static OP* pp_common_methstart(pTHX) {
  SV* self = av_shift(GvAV(PL_defgv));

  if(SvROK(self))
    /* TODO: Should handle this somehow */
    croak("Cannot invoke common method on an instance");

  save_clearsv(&PAD_SVl(1));
  sv_setsv(PAD_SVl(1), self);

  return PL_op->op_next;
}

OP* ClassPlain_newCOMMONMETHSTARTOP(pTHX_ U32 flags) {
  OP* op = newOP_CUSTOM(&pp_common_methstart, flags);
  op->op_private = (U8)(flags >> 8);
  return op;
}

/* The classdata on the currently-compiling class */
static ClassMeta *S_current_parsed_class(pTHX) {
  SV** svp = hv_fetchs(GvHV(PL_hintgv), "Class::Plain/current_parsed_class", 0);
  if(!svp || !*svp || !SvOK(*svp))
    return NULL;
  return (ClassMeta *)(intptr_t)SvIV(*svp);
}

static bool S_have_current_parsed_class(pTHX) {
  SV** svp = hv_fetchs(GvHV(PL_hintgv), "Class::Plain/current_parsed_class", 0);
  if(!svp || !*svp)
    return false;

  if(SvOK(*svp) && SvIV(*svp))
    return true;

  return false;
}

static void S_current_parsed_class_set(pTHX_ ClassMeta *class) {
  SV* sv = *hv_fetchs(GvHV(PL_hintgv), "Class::Plain/current_parsed_class", GV_ADD);
  sv_setiv(sv, (IV)(intptr_t)class);
}

static bool S_is_valid_ident_utf8(pTHX_ const U8* s) {
  const U8* e = s + strlen((char *)s);

  if(!isIDFIRST_utf8_safe(s, e))
    return false;

  s += UTF8SKIP(s);
  while(*s) {
    if(!isIDCONT_utf8_safe(s, e))
      return false;
    s += UTF8SKIP(s);
  }

  return true;
}

static void inplace_trim_whitespace(SV* sv)
{
  if(!SvPOK(sv) || !SvCUR(sv))
    return;

  char *dst = SvPVX(sv);
  char *src = dst;

  while(*src && isSPACE(*src))
    src++;

  if(src > dst) {
    size_t offset = src - dst;
    Move(src, dst, SvCUR(sv) - offset, char);
    SvCUR(sv) -= offset;
  }

  src = dst + SvCUR(sv) - 1;
  while(src > dst && isSPACE(*src))
    src--;

  SvCUR(sv) = src - dst + 1;
  dst[SvCUR(sv)] = 0;
}

static void S_apply_method_common(pTHX_ MethodMeta* class, const char *val, void* _data) {
  class->is_common = true;
}

static struct MethodAttributeDefinition method_attributes[] = {
  { "common",   &S_apply_method_common,   0 },
  { 0 }
};

/*******************
 * Custom Keywords *
 *******************/

static int build_classlike(pTHX_ OP* *out, XSParseKeywordPiece* args[], size_t nargs, void* hookdata) {
  int argi = 0;


  SV* package_name = args[argi++]->sv;
  /* Grrr; XPK bug */
  if(!package_name)
    croak("Expected a class name after 'class'");

  IV type = (IV)(intptr_t)hookdata;

  ClassMeta* class = ClassPlain_create_class(aTHX_ type, package_name);

  if (type == 1) {
    class->is_role = 1;
  }

  int nattrs = args[argi++]->i;
  if(nattrs) {
    int i;
    for(i = 0; i < nattrs; i++) {
      SV* attrname = args[argi]->attr.name;
      SV* attrval  = args[argi]->attr.value;

      inplace_trim_whitespace(attrval);

      ClassPlain_class_apply_attribute(aTHX_ class, SvPVX(attrname), attrval);

      argi++;
    }
  }

  ClassPlain_begin_class_block(aTHX_ class);

  /* At this point XS::Parse::Keyword has parsed all it can. From here we will
   * take over to perform the odd "block or statement" behaviour of `class`
   * keywords
   */

  bool exists_class_block;

  if(lex_consume_unichar('{')) {
    exists_class_block = true;
    ENTER;
  }
  else if(lex_consume_unichar(';')) {
    exists_class_block = false;
  }
  else
    croak("Expected a block or ';'");

  /* CARGOCULT from perl/op.c:Perl_package() */
  {
    SAVEGENERICSV(PL_curstash);
    save_item(PL_curstname);

    PL_curstash = (HV *)SvREFCNT_inc(gv_stashsv(class->name, GV_ADD));
    sv_setsv(PL_curstname, package_name);

    PL_hints |= HINT_BLOCK_SCOPE;
    PL_parser->copline = NOLINE;
  }

  if (exists_class_block) {
    I32 save_ix = block_start(TRUE);
    S_current_parsed_class_set(aTHX_ class);

    OP* body = parse_stmtseq(0);
    body = block_end(save_ix, body);

    if(!lex_consume_unichar('}'))
      croak("Expected }");

    // the end of the class block

    AV* role_names = class->role_names;
    for (int32_t i = 0; i < av_count(role_names); i++) {
      SV* role_name = AvARRAY(role_names)[i];
      if (role_name) {
        // The source code of Role::Tiny->import
        SV* sv_source_code = sv_2mortal(newSVpv("", 0));
        sv_catpv(sv_source_code, "{\n");
        sv_catpv(sv_source_code, "  package ");
        sv_catpv(sv_source_code, SvPV_nolen(class->name));
        sv_catpv(sv_source_code, ";\n");
        sv_catpv(sv_source_code, "  Role::Tiny::With::with(");
        sv_catpv(sv_source_code, SvPV_nolen(role_name));
        sv_catpv(sv_source_code, ");\n");
        sv_catpv(sv_source_code, "}\n");

        // Role::Tiny->import
        Perl_eval_pv(aTHX_ SvPV_nolen(sv_source_code), 1);
      }
    }

    LEAVE;

    /* CARGOCULT from perl/perly.y:PACKAGE BAREWORD BAREWORD '{' */
    /* a block is a loop that happens once */
    *out = op_append_elem(OP_LINESEQ,
      newWHILEOP(0, 1, NULL, NULL, body, NULL, 0),
      newSVOP(OP_CONST, 0, &PL_sv_yes));
    return KEYWORD_PLUGIN_STMT;
  }
  else {
    croak("The %s class must have its block", SvPV_nolen(class->name));
  }
}

static const struct XSParseKeywordPieceType pieces_classlike[] = {
  XPK_PACKAGENAME,
  /* This should really a repeated (tagged?) choice of a number of things, but
   * right now there's only one thing permitted here anyway
   */
  XPK_ATTRIBUTES,
  {0}
};

static const struct XSParseKeywordHooks kwhooks_class = {
  .permit_hintkey = "Class::Plain/class",
  .pieces = pieces_classlike,
  .build = &build_classlike,
};

static const struct XSParseKeywordHooks kwhooks_role = {
  .permit_hintkey = "Class::Plain/role",
  .pieces = pieces_classlike,
  .build = &build_classlike,
};

static void check_field(pTHX_ void* hookdata) {
  char *kwname = hookdata;

  if(!S_have_current_parsed_class(aTHX))
    croak("Cannot '%s' outside of 'class'", kwname);

  if(!sv_eq(PL_curstname, S_current_parsed_class(aTHX)->name))
    croak("Current package name no longer matches current class (%" SVf " vs %" SVf ")",
      PL_curstname, S_current_parsed_class(aTHX)->name);
}

static int build_field(pTHX_ OP* *out, XSParseKeywordPiece* args[], size_t nargs, void* hookdata) {
  int argi = 0;

  SV* name = args[argi++]->sv;

  FieldMeta *field_class = ClassPlain_class_add_field(aTHX_ S_current_parsed_class(aTHX), name);
  SvREFCNT_dec(name);

  int nattrs = args[argi++]->i;
  if(nattrs) {
    while(argi < (nattrs+2)) {
      SV* attrname = args[argi]->attr.name;
      SV* attrval  = args[argi]->attr.value;

      inplace_trim_whitespace(attrval);

      ClassPlain_field_apply_attribute(aTHX_ field_class, SvPVX(attrname), attrval);

      if(attrval)
        SvREFCNT_dec(attrval);

      argi++;
    }
  }

  return KEYWORD_PLUGIN_STMT;
}

static const struct XSParseKeywordHooks kwhooks_field = {
  .flags = XPK_FLAG_STMT,

  .check = &check_field,

  .permit_hintkey = "Class::Plain/field",
  .pieces = (const struct XSParseKeywordPieceType []){
    XPK_IDENT,
    XPK_ATTRIBUTES,
    {0}
  },
  .build = &build_field,
};
static bool parse_method_permit(pTHX_ void* hookdata)
{
  if(!S_have_current_parsed_class(aTHX))
    croak("Cannot 'method' outside of 'class'");

  if(!sv_eq(PL_curstname, S_current_parsed_class(aTHX)->name))
    croak("Current package name no longer matches current class (%" SVf " vs %" SVf ")",
      PL_curstname, S_current_parsed_class(aTHX)->name);

  return true;
}

static void parse_method_pre_subparse(pTHX_ struct XSParseSublikeContext* ctx, void* hookdata) {
  /* While creating the new scope CV we need to ENTER a block so as not to
   * break any interpvars
   */
  ENTER;
  SAVESPTR(PL_comppad);
  SAVESPTR(PL_comppad_name);
  SAVESPTR(PL_curpad);

  intro_my();

  MethodMeta* current_parsed_method;
  Newxz(current_parsed_method, 1, MethodMeta);

  current_parsed_method->name = SvREFCNT_inc(ctx->name);

  hv_stores(ctx->moddata, "Class::Plain/current_parsed_method", newSVuv(PTR2UV(current_parsed_method)));

  LEAVE;
}

static bool parse_method_filter_attr(pTHX_ struct XSParseSublikeContext* ctx, SV* attr, SV* val, void* hookdata) {
  MethodMeta* current_parsed_method = NUM2PTR(MethodMeta* , SvUV(*hv_fetchs(ctx->moddata, "Class::Plain/current_parsed_method", 0)));

  struct MethodAttributeDefinition *def;
  for(def = method_attributes; def->attrname; def++) {
    if(!strEQ(SvPVX(attr), def->attrname))
      continue;

    /* TODO: We might want to wrap the CV in some sort of MethodMeta struct
     * but for now we'll just pass the XSParseSublikeContext context */
    (*def->apply)(aTHX_ current_parsed_method, SvPOK(val) ? SvPVX(val) : NULL, def->applydata);

    return true;
  }

  /* No error, just let it fall back to usual attribute handling */
  return false;
}

static void parse_method_post_blockstart(pTHX_ struct XSParseSublikeContext* ctx, void* hookdata) {

  MethodMeta* current_parsed_method = NUM2PTR(MethodMeta* , SvUV(*hv_fetchs(ctx->moddata, "Class::Plain/current_parsed_method", 0)));
  if(current_parsed_method->is_common) {
    IV var_index = pad_add_name_pvs("$class", 0, NULL, NULL);
    if (!(var_index == 1)) {
      croak("[Unexpected]Invalid index of the $class variable:%d", (int)var_index);
    }
  }
  else {
    IV var_index = pad_add_name_pvs("$self", 0, NULL, NULL);
    if(var_index != 1) {
      croak("[Unexpected]Invalid index of the $self variable:%d", (int)var_index);
    }
  }

  intro_my();
}

static void parse_method_pre_blockend(pTHX_ struct XSParseSublikeContext* ctx, void* hookdata) {

  MethodMeta* current_parsed_method = NUM2PTR(MethodMeta* , SvUV(*hv_fetchs(ctx->moddata, "Class::Plain/current_parsed_method", 0)));

  /* If we have no ctx->body that means this was a bodyless method
   * declaration; a required method
   */
  if (ctx->body) {
    if(current_parsed_method->is_common) {
      ctx->body = op_append_list(OP_LINESEQ,
        ClassPlain_newCOMMONMETHSTARTOP(aTHX_ 0 |
          (0)),
        ctx->body);
    }
    else {
      OP* fieldops = NULL, *methstartop;
      fieldops = op_append_list(OP_LINESEQ, fieldops,
        newSTATEOP(0, NULL, NULL));
      fieldops = op_append_list(OP_LINESEQ, fieldops,
        (methstartop = ClassPlain_newMETHSTARTOP(aTHX_ 0 |
          (0) |
          (0))));

      ctx->body = op_append_list(OP_LINESEQ, fieldops, ctx->body);
    }
  }
}

static void parse_method_post_newcv(pTHX_ struct XSParseSublikeContext* ctx, void* hookdata) {
  MethodMeta* current_parsed_method;
  {
    SV* tmpsv = *hv_fetchs(ctx->moddata, "Class::Plain/current_parsed_method", 0);
    current_parsed_method = NUM2PTR(MethodMeta* , SvUV(tmpsv));
    sv_setuv(tmpsv, 0);
  }

  if(ctx->cv) {
    CvMETHOD_on(ctx->cv);
  }

  if(ctx->name && (ctx->actions & XS_PARSE_SUBLIKE_ACTION_INSTALL_SYMBOL)) {
    MethodMeta* method = ClassPlain_class_add_method(aTHX_ S_current_parsed_class(aTHX), ctx->name);
    method->is_common = current_parsed_method->is_common;

    // "sub foo;" means requred method in roles.
    if (!ctx->body) {
      method->is_required = 1;

      if (method->class->is_role) {
        if (method->is_required) {
          // The source code of Role::Tiny->import
          SV* sv_source_code = sv_2mortal(newSVpv("", 0));
          sv_catpv(sv_source_code, "{\n");
          sv_catpv(sv_source_code, "  package ");
          sv_catpv(sv_source_code, SvPV_nolen(method->class->name));
          sv_catpv(sv_source_code, ";\n");
          sv_catpv(sv_source_code, "  requires('");
          sv_catpv(sv_source_code, SvPV_nolen(method->name));
          sv_catpv(sv_source_code, "');\n");
          sv_catpv(sv_source_code, "}\n");

          // Role::Tiny->import
          Perl_eval_pv(aTHX_ SvPV_nolen(sv_source_code), 1);
        }
      }
    }
  }

  SvREFCNT_dec(current_parsed_method->name);
  Safefree(current_parsed_method);
}

static struct XSParseSublikeHooks parse_method_hooks = {
  .flags           = XS_PARSE_SUBLIKE_FLAG_FILTERATTRS |
                     XS_PARSE_SUBLIKE_COMPAT_FLAG_DYNAMIC_ACTIONS |
                     XS_PARSE_SUBLIKE_FLAG_BODY_OPTIONAL,
  .permit_hintkey  = "Class::Plain/method",
  .permit          = parse_method_permit,
  .pre_subparse    = parse_method_pre_subparse,
  .filter_attr     = parse_method_filter_attr,
  .post_blockstart = parse_method_post_blockstart,
  .pre_blockend    = parse_method_pre_blockend,
  .post_newcv      = parse_method_post_newcv,
};

/* internal function shared by various *.c files */
void ClassPlain_need_PLparser(pTHX)
{
  if(!PL_parser) {
    /* We need to generate just enough of a PL_parser to keep newSTATEOP()
     * happy, otherwise it will SIGSEGV (RT133258)
     */
    SAVEVPTR(PL_parser);
    Newxz(PL_parser, 1, yy_parser);
    SAVEFREEPV(PL_parser);

    PL_parser->copline = NOLINE;
  }
}

MODULE = Class::Plain    PACKAGE = Class::Plain::MetaFunctions

BOOT:
  XopENTRY_set(&xop_methstart, xop_name, "methstart");
  XopENTRY_set(&xop_methstart, xop_desc, "enter method");
  XopENTRY_set(&xop_methstart, xop_class, OA_BASEOP);
  Perl_custom_op_register(aTHX_ &pp_methstart, &xop_methstart);

  boot_xs_parse_keyword(0.22); /* XPK_AUTOSEMI */

  register_xs_parse_keyword("class", &kwhooks_class, (void*)0);

  // Note: Using kwhooks_role is maybe correct, but it doesn't work well
  register_xs_parse_keyword("role",  &kwhooks_class,  (void*)METATYPE_ROLE);

  register_xs_parse_keyword("field", &kwhooks_field, "field");

  boot_xs_parse_sublike(0.15); /* dynamic actions */

  register_xs_parse_sublike("method", &parse_method_hooks, (void*)0);