ruby/vm_core.h

#ifndef RUBY_VM_CORE_H
#define RUBY_VM_CORE_H
/**********************************************************************

  vm_core.h -

  $Author$
  created at: 04/01/01 19:41:38 JST

  Copyright (C) 2004-2007 Koichi Sasada

**********************************************************************/

/*
 * Enable check mode.
 *   1: enable local assertions.
 */
#ifndef VM_CHECK_MODE

// respect RUBY_DUBUG: if given n is 0, then use RUBY_DEBUG
#define N_OR_RUBY_DEBUG(n) (((n) > 0) ? (n) : RUBY_DEBUG)

#define VM_CHECK_MODE N_OR_RUBY_DEBUG(0)
#endif

/**
 * VM Debug Level
 *
 * debug level:
 *  0: no debug output
 *  1: show instruction name
 *  2: show stack frame when control stack frame is changed
 *  3: show stack status
 *  4: show register
 *  5:
 * 10: gc check
 */

#ifndef VMDEBUG
#define VMDEBUG 0
#endif

#if 0
#undef  VMDEBUG
#define VMDEBUG 3
#endif

#include "ruby/internal/config.h"

#include <stddef.h>
#include <signal.h>
#include <stdarg.h>

#include "ruby_assert.h"

#if VM_CHECK_MODE > 0
#define VM_ASSERT(expr) RUBY_ASSERT_MESG_WHEN(VM_CHECK_MODE > 0, expr, #expr)
#define VM_UNREACHABLE(func) rb_bug(#func ": unreachable")

#else
#define VM_ASSERT(expr) ((void)0)
#define VM_UNREACHABLE(func) UNREACHABLE
#endif

#include <setjmp.h>

#include "ruby/internal/stdbool.h"
#include "ccan/list/list.h"
#include "id.h"
#include "internal.h"
#include "internal/array.h"
#include "internal/serial.h"
#include "internal/vm.h"
#include "method.h"
#include "node.h"
#include "ruby/ruby.h"
#include "ruby/st.h"
#include "ruby_atomic.h"
#include "vm_opts.h"

#include "ruby/thread_native.h"
#if   defined(_WIN32)
#include "thread_win32.h"
#elif defined(HAVE_PTHREAD_H)
#include "thread_pthread.h"
#endif

#define RUBY_VM_THREAD_MODEL 2

/*
 * implementation selector of get_insn_info algorithm
 *   0: linear search
 *   1: binary search
 *   2: succinct bitvector
 */
#ifndef VM_INSN_INFO_TABLE_IMPL
# define VM_INSN_INFO_TABLE_IMPL 2
#endif

#if defined(NSIG_MAX)           /* POSIX issue 8 */
# undef NSIG
# define NSIG NSIG_MAX
#elif defined(_SIG_MAXSIG)      /* FreeBSD */
# undef NSIG
# define NSIG _SIG_MAXSIG
#elif defined(_SIGMAX)          /* QNX */
# define NSIG (_SIGMAX + 1)
#elif defined(NSIG)             /* 99% of everything else */
# /* take it */
#else                           /* Last resort */
# define NSIG (sizeof(sigset_t) * CHAR_BIT + 1)
#endif

#define RUBY_NSIG NSIG

#if defined(SIGCLD)
#  define RUBY_SIGCHLD    (SIGCLD)
#elif defined(SIGCHLD)
#  define RUBY_SIGCHLD    (SIGCHLD)
#else
#  define RUBY_SIGCHLD    (0)
#endif

/* platforms with broken or non-existent SIGCHLD work by polling */
#if defined(__APPLE__)
#  define SIGCHLD_LOSSY (1)
#else
#  define SIGCHLD_LOSSY (0)
#endif

/* define to 0 to test old code path */
#define WAITPID_USE_SIGCHLD (RUBY_SIGCHLD || SIGCHLD_LOSSY)

#if defined(SIGSEGV) && defined(HAVE_SIGALTSTACK) && defined(SA_SIGINFO) && !defined(__NetBSD__)
#  define USE_SIGALTSTACK
void *rb_allocate_sigaltstack(void);
void *rb_register_sigaltstack(void *);
#  define RB_ALTSTACK_INIT(var, altstack) var = rb_register_sigaltstack(altstack)
#  define RB_ALTSTACK_FREE(var) xfree(var)
#  define RB_ALTSTACK(var)  var
#else /* noop */
#  define RB_ALTSTACK_INIT(var, altstack)
#  define RB_ALTSTACK_FREE(var)
#  define RB_ALTSTACK(var) (0)
#endif

/*****************/
/* configuration */
/*****************/

/* gcc ver. check */
#if defined(__GNUC__) && __GNUC__ >= 2

#if OPT_TOKEN_THREADED_CODE
#if OPT_DIRECT_THREADED_CODE
#undef OPT_DIRECT_THREADED_CODE
#endif
#endif

#else /* defined(__GNUC__) && __GNUC__ >= 2 */

/* disable threaded code options */
#if OPT_DIRECT_THREADED_CODE
#undef OPT_DIRECT_THREADED_CODE
#endif
#if OPT_TOKEN_THREADED_CODE
#undef OPT_TOKEN_THREADED_CODE
#endif
#endif

/* call threaded code */
#if    OPT_CALL_THREADED_CODE
#if    OPT_DIRECT_THREADED_CODE
#undef OPT_DIRECT_THREADED_CODE
#endif /* OPT_DIRECT_THREADED_CODE */
#if    OPT_STACK_CACHING
#undef OPT_STACK_CACHING
#endif /* OPT_STACK_CACHING */
#endif /* OPT_CALL_THREADED_CODE */

void rb_vm_encoded_insn_data_table_init(void);
typedef unsigned long rb_num_t;
typedef   signed long rb_snum_t;

enum ruby_tag_type {
    RUBY_TAG_NONE	= 0x0,
    RUBY_TAG_RETURN	= 0x1,
    RUBY_TAG_BREAK	= 0x2,
    RUBY_TAG_NEXT	= 0x3,
    RUBY_TAG_RETRY	= 0x4,
    RUBY_TAG_REDO	= 0x5,
    RUBY_TAG_RAISE	= 0x6,
    RUBY_TAG_THROW	= 0x7,
    RUBY_TAG_FATAL	= 0x8,
    RUBY_TAG_MASK	= 0xf
};

#define TAG_NONE	RUBY_TAG_NONE
#define TAG_RETURN	RUBY_TAG_RETURN
#define TAG_BREAK	RUBY_TAG_BREAK
#define TAG_NEXT	RUBY_TAG_NEXT
#define TAG_RETRY	RUBY_TAG_RETRY
#define TAG_REDO	RUBY_TAG_REDO
#define TAG_RAISE	RUBY_TAG_RAISE
#define TAG_THROW	RUBY_TAG_THROW
#define TAG_FATAL	RUBY_TAG_FATAL
#define TAG_MASK	RUBY_TAG_MASK

enum ruby_vm_throw_flags {
    VM_THROW_NO_ESCAPE_FLAG = 0x8000,
    VM_THROW_STATE_MASK = 0xff
};

/* forward declarations */
struct rb_thread_struct;
struct rb_control_frame_struct;

/* iseq data type */
typedef struct rb_compile_option_struct rb_compile_option_t;

struct iseq_inline_cache_entry {
    rb_serial_t ic_serial;
    const rb_cref_t *ic_cref;
    VALUE value;
};

struct iseq_inline_iv_cache_entry {
    struct rb_iv_index_tbl_entry *entry;
};

union iseq_inline_storage_entry {
    struct {
	struct rb_thread_struct *running_thread;
	VALUE value;
    } once;
    struct iseq_inline_cache_entry cache;
    struct iseq_inline_iv_cache_entry iv_cache;
};

struct rb_calling_info {
    VALUE block_handler;
    VALUE recv;
    int argc;
    int kw_splat;
};

struct rb_execution_context_struct;

#if 1
#define CoreDataFromValue(obj, type) (type*)DATA_PTR(obj)
#else
#define CoreDataFromValue(obj, type) (type*)rb_data_object_get(obj)
#endif
#define GetCoreDataFromValue(obj, type, ptr) ((ptr) = CoreDataFromValue((obj), type))

typedef struct rb_iseq_location_struct {
    VALUE pathobj;      /* String (path) or Array [path, realpath]. Frozen. */
    VALUE base_label;   /* String */
    VALUE label;        /* String */
    VALUE first_lineno; /* TODO: may be unsigned short */
    int node_id;
    rb_code_location_t code_location;
} rb_iseq_location_t;

#define PATHOBJ_PATH     0
#define PATHOBJ_REALPATH 1

static inline VALUE
pathobj_path(VALUE pathobj)
{
    if (RB_TYPE_P(pathobj, T_STRING)) {
	return pathobj;
    }
    else {
	VM_ASSERT(RB_TYPE_P(pathobj, T_ARRAY));
	return RARRAY_AREF(pathobj, PATHOBJ_PATH);
    }
}

static inline VALUE
pathobj_realpath(VALUE pathobj)
{
    if (RB_TYPE_P(pathobj, T_STRING)) {
	return pathobj;
    }
    else {
	VM_ASSERT(RB_TYPE_P(pathobj, T_ARRAY));
	return RARRAY_AREF(pathobj, PATHOBJ_REALPATH);
    }
}

/* Forward declarations */
struct rb_mjit_unit;

struct rb_iseq_constant_body {
    enum iseq_type {
	ISEQ_TYPE_TOP,
	ISEQ_TYPE_METHOD,
	ISEQ_TYPE_BLOCK,
	ISEQ_TYPE_CLASS,
	ISEQ_TYPE_RESCUE,
	ISEQ_TYPE_ENSURE,
	ISEQ_TYPE_EVAL,
	ISEQ_TYPE_MAIN,
	ISEQ_TYPE_PLAIN
    } type;              /* instruction sequence type */

    unsigned int iseq_size;
    VALUE *iseq_encoded; /* encoded iseq (insn addr and operands) */

    /**
     * parameter information
     *
     *  def m(a1, a2, ..., aM,                    # mandatory
     *        b1=(...), b2=(...), ..., bN=(...),  # optional
     *        *c,                                 # rest
     *        d1, d2, ..., dO,                    # post
     *        e1:(...), e2:(...), ..., eK:(...),  # keyword
     *        **f,                                # keyword_rest
     *        &g)                                 # block
     * =>
     *
     *  lead_num     = M
     *  opt_num      = N
     *  rest_start   = M+N
     *  post_start   = M+N+(*1)
     *  post_num     = O
     *  keyword_num  = K
     *  block_start  = M+N+(*1)+O+K
     *  keyword_bits = M+N+(*1)+O+K+(&1)
     *  size         = M+N+O+(*1)+K+(&1)+(**1) // parameter size.
     */

    struct {
	struct {
	    unsigned int has_lead   : 1;
	    unsigned int has_opt    : 1;
	    unsigned int has_rest   : 1;
	    unsigned int has_post   : 1;
	    unsigned int has_kw     : 1;
	    unsigned int has_kwrest : 1;
	    unsigned int has_block  : 1;

	    unsigned int ambiguous_param0 : 1; /* {|a|} */
	    unsigned int accepts_no_kwarg : 1;
            unsigned int ruby2_keywords: 1;
	} flags;

	unsigned int size;

	int lead_num;
	int opt_num;
	int rest_start;
	int post_start;
	int post_num;
	int block_start;

	const VALUE *opt_table; /* (opt_num + 1) entries. */
	/* opt_num and opt_table:
	 *
	 * def foo o1=e1, o2=e2, ..., oN=eN
	 * #=>
	 *   # prologue code
	 *   A1: e1
	 *   A2: e2
	 *   ...
	 *   AN: eN
	 *   AL: body
	 * opt_num = N
	 * opt_table = [A1, A2, ..., AN, AL]
	 */

	const struct rb_iseq_param_keyword {
	    int num;
	    int required_num;
	    int bits_start;
	    int rest_start;
	    const ID *table;
            VALUE *default_values;
	} *keyword;
    } param;

    rb_iseq_location_t location;

    /* insn info, must be freed */
    struct iseq_insn_info {
	const struct iseq_insn_info_entry *body;
	unsigned int *positions;
	unsigned int size;
#if VM_INSN_INFO_TABLE_IMPL == 2
	struct succ_index_table *succ_index_table;
#endif
    } insns_info;

    const ID *local_table;		/* must free */

    /* catch table */
    struct iseq_catch_table *catch_table;

    /* for child iseq */
    const struct rb_iseq_struct *parent_iseq;
    struct rb_iseq_struct *local_iseq; /* local_iseq->flip_cnt can be modified */

    union iseq_inline_storage_entry *is_entries;
    struct rb_call_data *call_data; //struct rb_call_data calls[ci_size];

    struct {
	rb_snum_t flip_count;
	VALUE coverage;
        VALUE pc2branchindex;
	VALUE *original_iseq;
    } variable;

    unsigned int local_table_size;
    unsigned int is_size;
    unsigned int ci_size;
    unsigned int stack_max; /* for stack overflow check */

    char catch_except_p; /* If a frame of this ISeq may catch exception, set TRUE */
    bool builtin_inline_p; // This ISeq's builtin func is safe to be inlined by MJIT
    struct rb_id_table *outer_variables;

#if USE_MJIT
    /* The following fields are MJIT related info.  */
    VALUE (*jit_func)(struct rb_execution_context_struct *,
                      struct rb_control_frame_struct *); /* function pointer for loaded native code */
    long unsigned total_calls; /* number of total calls with `mjit_exec()` */
    struct rb_mjit_unit *jit_unit;
#endif
};

/* T_IMEMO/iseq */
/* typedef rb_iseq_t is in method.h */
struct rb_iseq_struct {
    VALUE flags; /* 1 */
    VALUE wrapper; /* 2 */

    struct rb_iseq_constant_body *body;  /* 3 */

    union { /* 4, 5 words */
	struct iseq_compile_data *compile_data; /* used at compile time */

	struct {
	    VALUE obj;
	    int index;
	} loader;

        struct {
            struct rb_hook_list_struct *local_hooks;
            rb_event_flag_t global_trace_events;
        } exec;
    } aux;
};

#ifndef USE_LAZY_LOAD
#define USE_LAZY_LOAD 0
#endif

#if USE_LAZY_LOAD
const rb_iseq_t *rb_iseq_complete(const rb_iseq_t *iseq);
#endif

static inline const rb_iseq_t *
rb_iseq_check(const rb_iseq_t *iseq)
{
#if USE_LAZY_LOAD
    if (iseq->body == NULL) {
	rb_iseq_complete((rb_iseq_t *)iseq);
    }
#endif
    return iseq;
}

static inline const rb_iseq_t *
def_iseq_ptr(rb_method_definition_t *def)
{
//TODO: re-visit. to check the bug, enable this assertion.
#if VM_CHECK_MODE > 0
    if (def->type != VM_METHOD_TYPE_ISEQ) rb_bug("def_iseq_ptr: not iseq (%d)", def->type);
#endif
    return rb_iseq_check(def->body.iseq.iseqptr);
}

enum ruby_special_exceptions {
    ruby_error_reenter,
    ruby_error_nomemory,
    ruby_error_sysstack,
    ruby_error_stackfatal,
    ruby_error_stream_closed,
    ruby_special_error_count
};

enum ruby_basic_operators {
    BOP_PLUS,
    BOP_MINUS,
    BOP_MULT,
    BOP_DIV,
    BOP_MOD,
    BOP_EQ,
    BOP_EQQ,
    BOP_LT,
    BOP_LE,
    BOP_LTLT,
    BOP_AREF,
    BOP_ASET,
    BOP_LENGTH,
    BOP_SIZE,
    BOP_EMPTY_P,
    BOP_NIL_P,
    BOP_SUCC,
    BOP_GT,
    BOP_GE,
    BOP_NOT,
    BOP_NEQ,
    BOP_MATCH,
    BOP_FREEZE,
    BOP_UMINUS,
    BOP_MAX,
    BOP_MIN,
    BOP_CALL,
    BOP_AND,
    BOP_OR,

    BOP_LAST_
};

#define GetVMPtr(obj, ptr) \
  GetCoreDataFromValue((obj), rb_vm_t, (ptr))

struct rb_vm_struct;
typedef void rb_vm_at_exit_func(struct rb_vm_struct*);

typedef struct rb_at_exit_list {
    rb_vm_at_exit_func *func;
    struct rb_at_exit_list *next;
} rb_at_exit_list;

struct rb_objspace;
struct rb_objspace *rb_objspace_alloc(void);
void rb_objspace_free(struct rb_objspace *);
void rb_objspace_call_finalizer(struct rb_objspace *);

typedef struct rb_hook_list_struct {
    struct rb_event_hook_struct *hooks;
    rb_event_flag_t events;
    unsigned int need_clean;
    unsigned int running;
} rb_hook_list_t;


// see builtin.h for definition
typedef const struct rb_builtin_function *RB_BUILTIN;

typedef struct rb_vm_struct {
    VALUE self;

    struct {
        struct list_head set;
        unsigned int cnt;
        unsigned int blocking_cnt;

        struct rb_ractor_struct *main_ractor;
        struct rb_thread_struct *main_thread; // == vm->ractor.main_ractor->threads.main

        struct {
            // monitor
            rb_nativethread_lock_t lock;
            struct rb_ractor_struct *lock_owner;
            unsigned int lock_rec;

            // barrier
            bool barrier_waiting;
            unsigned int barrier_cnt;
            rb_nativethread_cond_t barrier_cond;

            // join at exit
            rb_nativethread_cond_t terminate_cond;
            bool terminate_waiting;
        } sync;
    } ractor;

#ifdef USE_SIGALTSTACK
    void *main_altstack;
#endif

    rb_serial_t fork_gen;
    rb_nativethread_lock_t waitpid_lock;
    struct list_head waiting_pids; /* PID > 0: <=> struct waitpid_state */
    struct list_head waiting_grps; /* PID <= 0: <=> struct waitpid_state */
    struct list_head waiting_fds; /* <=> struct waiting_fd */

    /* set in single-threaded processes only: */
    volatile int ubf_async_safe;

    unsigned int running: 1;
    unsigned int thread_abort_on_exception: 1;
    unsigned int thread_report_on_exception: 1;
    unsigned int thread_ignore_deadlock: 1;

    /* object management */
    VALUE mark_object_ary;
    const VALUE special_exceptions[ruby_special_error_count];

    /* load */
    VALUE top_self;
    VALUE load_path;
    VALUE load_path_snapshot;
    VALUE load_path_check_cache;
    VALUE expanded_load_path;
    VALUE loaded_features;
    VALUE loaded_features_snapshot;
    struct st_table *loaded_features_index;
    struct st_table *loading_table;

    /* signal */
    struct {
	VALUE cmd[RUBY_NSIG];
    } trap_list;

    /* hook */
    rb_hook_list_t global_hooks;

    /* relation table of ensure - rollback for callcc */
    struct st_table *ensure_rollback_table;

    /* postponed_job (async-signal-safe, NOT thread-safe) */
    struct rb_postponed_job_struct *postponed_job_buffer;
    rb_atomic_t postponed_job_index;

    int src_encoding_index;

    /* workqueue (thread-safe, NOT async-signal-safe) */
    struct list_head workqueue; /* <=> rb_workqueue_job.jnode */
    rb_nativethread_lock_t workqueue_lock;

    VALUE orig_progname, progname;
    VALUE coverages;
    int coverage_mode;

    st_table * defined_module_hash;

    struct rb_objspace *objspace;

    rb_at_exit_list *at_exit;

    VALUE *defined_strings;
    st_table *frozen_strings;

    const struct rb_builtin_function *builtin_function_table;
    int builtin_inline_index;

    struct rb_id_table *negative_cme_table;

#if USE_VM_CLOCK
    uint32_t clock;
#endif

    /* params */
    struct { /* size in byte */
	size_t thread_vm_stack_size;
	size_t thread_machine_stack_size;
	size_t fiber_vm_stack_size;
	size_t fiber_machine_stack_size;
    } default_params;

    short redefined_flag[BOP_LAST_];
} rb_vm_t;

/* default values */

#define RUBY_VM_SIZE_ALIGN 4096

#define RUBY_VM_THREAD_VM_STACK_SIZE          ( 128 * 1024 * sizeof(VALUE)) /*  512 KB or 1024 KB */
#define RUBY_VM_THREAD_VM_STACK_SIZE_MIN      (   2 * 1024 * sizeof(VALUE)) /*    8 KB or   16 KB */
#define RUBY_VM_THREAD_MACHINE_STACK_SIZE     ( 128 * 1024 * sizeof(VALUE)) /*  512 KB or 1024 KB */
#define RUBY_VM_THREAD_MACHINE_STACK_SIZE_MIN (  16 * 1024 * sizeof(VALUE)) /*   64 KB or  128 KB */

#define RUBY_VM_FIBER_VM_STACK_SIZE           (  16 * 1024 * sizeof(VALUE)) /*   64 KB or  128 KB */
#define RUBY_VM_FIBER_VM_STACK_SIZE_MIN       (   2 * 1024 * sizeof(VALUE)) /*    8 KB or   16 KB */
#define RUBY_VM_FIBER_MACHINE_STACK_SIZE      (  64 * 1024 * sizeof(VALUE)) /*  256 KB or  512 KB */
#if defined(__powerpc64__)
#define RUBY_VM_FIBER_MACHINE_STACK_SIZE_MIN  (  32 * 1024 * sizeof(VALUE)) /*   128 KB or  256 KB */
#else
#define RUBY_VM_FIBER_MACHINE_STACK_SIZE_MIN  (  16 * 1024 * sizeof(VALUE)) /*   64 KB or  128 KB */
#endif

#if __has_feature(memory_sanitizer) || __has_feature(address_sanitizer)
/* It seems sanitizers consume A LOT of machine stacks */
#undef  RUBY_VM_THREAD_MACHINE_STACK_SIZE
#define RUBY_VM_THREAD_MACHINE_STACK_SIZE     (1024 * 1024 * sizeof(VALUE))
#undef  RUBY_VM_THREAD_MACHINE_STACK_SIZE_MIN
#define RUBY_VM_THREAD_MACHINE_STACK_SIZE_MIN ( 512 * 1024 * sizeof(VALUE))
#undef  RUBY_VM_FIBER_MACHINE_STACK_SIZE
#define RUBY_VM_FIBER_MACHINE_STACK_SIZE      ( 256 * 1024 * sizeof(VALUE))
#undef  RUBY_VM_FIBER_MACHINE_STACK_SIZE_MIN
#define RUBY_VM_FIBER_MACHINE_STACK_SIZE_MIN  ( 128 * 1024 * sizeof(VALUE))
#endif

/* optimize insn */
#define INTEGER_REDEFINED_OP_FLAG (1 << 0)
#define FLOAT_REDEFINED_OP_FLAG  (1 << 1)
#define STRING_REDEFINED_OP_FLAG (1 << 2)
#define ARRAY_REDEFINED_OP_FLAG  (1 << 3)
#define HASH_REDEFINED_OP_FLAG   (1 << 4)
/* #define BIGNUM_REDEFINED_OP_FLAG (1 << 5) */
#define SYMBOL_REDEFINED_OP_FLAG (1 << 6)
#define TIME_REDEFINED_OP_FLAG   (1 << 7)
#define REGEXP_REDEFINED_OP_FLAG (1 << 8)
#define NIL_REDEFINED_OP_FLAG    (1 << 9)
#define TRUE_REDEFINED_OP_FLAG   (1 << 10)
#define FALSE_REDEFINED_OP_FLAG  (1 << 11)
#define PROC_REDEFINED_OP_FLAG   (1 << 12)

#define BASIC_OP_UNREDEFINED_P(op, klass) (LIKELY((GET_VM()->redefined_flag[(op)]&(klass)) == 0))

#ifndef VM_DEBUG_BP_CHECK
#define VM_DEBUG_BP_CHECK 0
#endif

#ifndef VM_DEBUG_VERIFY_METHOD_CACHE
#define VM_DEBUG_VERIFY_METHOD_CACHE (VMDEBUG != 0)
#endif

struct rb_captured_block {
    VALUE self;
    const VALUE *ep;
    union {
	const rb_iseq_t *iseq;
	const struct vm_ifunc *ifunc;
	VALUE val;
    } code;
};

enum rb_block_handler_type {
    block_handler_type_iseq,
    block_handler_type_ifunc,
    block_handler_type_symbol,
    block_handler_type_proc
};

enum rb_block_type {
    block_type_iseq,
    block_type_ifunc,
    block_type_symbol,
    block_type_proc
};

struct rb_block {
    union {
	struct rb_captured_block captured;
	VALUE symbol;
	VALUE proc;
    } as;
    enum rb_block_type type;
};

typedef struct rb_control_frame_struct {
    const VALUE *pc;		/* cfp[0] */
    VALUE *sp;			/* cfp[1] */
    const rb_iseq_t *iseq;	/* cfp[2] */
    VALUE self;			/* cfp[3] / block[0] */
    const VALUE *ep;		/* cfp[4] / block[1] */
    const void *block_code;     /* cfp[5] / block[2] */ /* iseq or ifunc or forwarded block handler */
    VALUE *__bp__;              /* cfp[6] */ /* outside vm_push_frame, use vm_base_ptr instead. */

#if VM_DEBUG_BP_CHECK
    VALUE *bp_check;		/* cfp[7] */
#endif
} rb_control_frame_t;

extern const rb_data_type_t ruby_threadptr_data_type;

static inline struct rb_thread_struct *
rb_thread_ptr(VALUE thval)
{
    return (struct rb_thread_struct *)rb_check_typeddata(thval, &ruby_threadptr_data_type);
}

enum rb_thread_status {
    THREAD_RUNNABLE,
    THREAD_STOPPED,
    THREAD_STOPPED_FOREVER,
    THREAD_KILLED
};

#ifdef RUBY_JMP_BUF
typedef RUBY_JMP_BUF rb_jmpbuf_t;
#else
typedef void *rb_jmpbuf_t[5];
#endif

/*
  the members which are written in EC_PUSH_TAG() should be placed at
  the beginning and the end, so that entire region is accessible.
*/
struct rb_vm_tag {
    VALUE tag;
    VALUE retval;
    rb_jmpbuf_t buf;
    struct rb_vm_tag *prev;
    enum ruby_tag_type state;
    unsigned int lock_rec;
};

STATIC_ASSERT(rb_vm_tag_buf_offset, offsetof(struct rb_vm_tag, buf) > 0);
STATIC_ASSERT(rb_vm_tag_buf_end,
	      offsetof(struct rb_vm_tag, buf) + sizeof(rb_jmpbuf_t) <
	      sizeof(struct rb_vm_tag));

struct rb_vm_protect_tag {
    struct rb_vm_protect_tag *prev;
};

struct rb_unblock_callback {
    rb_unblock_function_t *func;
    void *arg;
};

struct rb_mutex_struct;

typedef struct rb_ensure_entry {
    VALUE marker;
    VALUE (*e_proc)(VALUE);
    VALUE data2;
} rb_ensure_entry_t;

typedef struct rb_ensure_list {
    struct rb_ensure_list *next;
    struct rb_ensure_entry entry;
} rb_ensure_list_t;

typedef char rb_thread_id_string_t[sizeof(rb_nativethread_id_t) * 2 + 3];

typedef struct rb_fiber_struct rb_fiber_t;

struct rb_waiting_list {
    struct rb_waiting_list *next;
    struct rb_thread_struct *thread;
    struct rb_fiber_struct *fiber;
};

struct rb_execution_context_struct {
    /* execution information */
    VALUE *vm_stack;		/* must free, must mark */
    size_t vm_stack_size;       /* size in word (byte size / sizeof(VALUE)) */
    rb_control_frame_t *cfp;

    struct rb_vm_tag *tag;
    struct rb_vm_protect_tag *protect_tag;

    /* interrupt flags */
    rb_atomic_t interrupt_flag;
    rb_atomic_t interrupt_mask; /* size should match flag */
#if USE_VM_CLOCK
    uint32_t checked_clock;
#endif

    rb_fiber_t *fiber_ptr;
    struct rb_thread_struct *thread_ptr;

    /* storage (ec (fiber) local) */
    struct rb_id_table *local_storage;
    VALUE local_storage_recursive_hash;
    VALUE local_storage_recursive_hash_for_trace;

    /* eval env */
    const VALUE *root_lep;
    VALUE root_svar;

    /* ensure & callcc */
    rb_ensure_list_t *ensure_list;

    /* trace information */
    struct rb_trace_arg_struct *trace_arg;

    /* temporary places */
    VALUE errinfo;
    VALUE passed_block_handler; /* for rb_iterate */

    uint8_t raised_flag; /* only 3 bits needed */

    /* n.b. only 7 bits needed, really: */
    BITFIELD(enum method_missing_reason, method_missing_reason, 8);

    VALUE private_const_reference;

    /* for GC */
    struct {
	VALUE *stack_start;
	VALUE *stack_end;
	size_t stack_maxsize;
	RUBY_ALIGNAS(SIZEOF_VALUE) jmp_buf regs;
    } machine;
};

#ifndef rb_execution_context_t
typedef struct rb_execution_context_struct rb_execution_context_t;
#define rb_execution_context_t rb_execution_context_t
#endif

// for builtin.h
#define VM_CORE_H_EC_DEFINED 1

// Set the vm_stack pointer in the execution context.
void rb_ec_set_vm_stack(rb_execution_context_t *ec, VALUE *stack, size_t size);

// Initialize the vm_stack pointer in the execution context and push the initial stack frame.
// @param ec the execution context to update.
// @param stack a pointer to the stack to use.
// @param size the size of the stack, as in `VALUE stack[size]`.
void rb_ec_initialize_vm_stack(rb_execution_context_t *ec, VALUE *stack, size_t size);

// Clear (set to `NULL`) the vm_stack pointer.
// @param ec the execution context to update.
void rb_ec_clear_vm_stack(rb_execution_context_t *ec);

struct rb_ext_config {
    bool ractor_safe;
};

typedef struct rb_ractor_struct rb_ractor_t;

typedef struct rb_thread_struct {
    struct list_node lt_node; // managed by a ractor
    VALUE self;
    rb_ractor_t *ractor;
    rb_vm_t *vm;

    rb_execution_context_t *ec;

    VALUE last_status; /* $? */

    /* for cfunc */
    struct rb_calling_info *calling;

    /* for load(true) */
    VALUE top_self;
    VALUE top_wrapper;

    /* thread control */
    rb_nativethread_id_t thread_id;
#ifdef NON_SCALAR_THREAD_ID
    rb_thread_id_string_t thread_id_string;
#endif
    BITFIELD(enum rb_thread_status, status, 2);
    /* bit flags */
    unsigned int to_kill : 1;
    unsigned int abort_on_exception: 1;
    unsigned int report_on_exception: 1;
    unsigned int pending_interrupt_queue_checked: 1;
    int8_t priority; /* -3 .. 3 (RUBY_THREAD_PRIORITY_{MIN,MAX}) */
    uint32_t running_time_us; /* 12500..800000 */

    native_thread_data_t native_thread_data;
    void *blocking_region_buffer;

    VALUE thgroup;
    VALUE value;

    /* temporary place of retval on OPT_CALL_THREADED_CODE */
#if OPT_CALL_THREADED_CODE
    VALUE retval;
#endif

    /* async errinfo queue */
    VALUE pending_interrupt_queue;
    VALUE pending_interrupt_mask_stack;

    /* interrupt management */
    rb_nativethread_lock_t interrupt_lock;
    struct rb_unblock_callback unblock;
    VALUE locking_mutex;
    struct rb_mutex_struct *keeping_mutexes;

    struct rb_waiting_list *join_list;

    union {
        struct {
            VALUE proc;
            VALUE args;
            int kw_splat;
        } proc;
        struct {
            VALUE (*func)(void *);
            void *arg;
        } func;
    } invoke_arg;

    enum thread_invoke_type {
        thread_invoke_type_none = 0,
        thread_invoke_type_proc,
        thread_invoke_type_ractor_proc,
        thread_invoke_type_func
    } invoke_type;

    /* statistics data for profiler */
    VALUE stat_insn_usage;

    /* fiber */
    rb_fiber_t *root_fiber;
    rb_jmpbuf_t root_jmpbuf;

    VALUE scheduler;
    unsigned blocking;

    /* misc */
    VALUE name;

    struct rb_ext_config ext_config;

#ifdef USE_SIGALTSTACK
    void *altstack;
#endif
} rb_thread_t;

typedef enum {
    VM_DEFINECLASS_TYPE_CLASS           = 0x00,
    VM_DEFINECLASS_TYPE_SINGLETON_CLASS = 0x01,
    VM_DEFINECLASS_TYPE_MODULE          = 0x02,
    /* 0x03..0x06 is reserved */
    VM_DEFINECLASS_TYPE_MASK            = 0x07
} rb_vm_defineclass_type_t;

#define VM_DEFINECLASS_TYPE(x) ((rb_vm_defineclass_type_t)(x) & VM_DEFINECLASS_TYPE_MASK)
#define VM_DEFINECLASS_FLAG_SCOPED         0x08
#define VM_DEFINECLASS_FLAG_HAS_SUPERCLASS 0x10
#define VM_DEFINECLASS_SCOPED_P(x) ((x) & VM_DEFINECLASS_FLAG_SCOPED)
#define VM_DEFINECLASS_HAS_SUPERCLASS_P(x) \
    ((x) & VM_DEFINECLASS_FLAG_HAS_SUPERCLASS)

/* iseq.c */
RUBY_SYMBOL_EXPORT_BEGIN

/* node -> iseq */
rb_iseq_t *rb_iseq_new         (const rb_ast_body_t *ast, VALUE name, VALUE path, VALUE realpath,                     const rb_iseq_t *parent, enum iseq_type);
rb_iseq_t *rb_iseq_new_top     (const rb_ast_body_t *ast, VALUE name, VALUE path, VALUE realpath,                     const rb_iseq_t *parent);
rb_iseq_t *rb_iseq_new_main    (const rb_ast_body_t *ast,             VALUE path, VALUE realpath,                     const rb_iseq_t *parent);
rb_iseq_t *rb_iseq_new_eval    (const rb_ast_body_t *ast, VALUE name, VALUE path, VALUE realpath, VALUE first_lineno, const rb_iseq_t *parent, int isolated_depth);
rb_iseq_t *rb_iseq_new_with_opt(const rb_ast_body_t *ast, VALUE name, VALUE path, VALUE realpath, VALUE first_lineno, const rb_iseq_t *parent, int isolated_depth,
                                enum iseq_type, const rb_compile_option_t*);

struct iseq_link_anchor;
struct rb_iseq_new_with_callback_callback_func {
    VALUE flags;
    VALUE reserved;
    void (*func)(rb_iseq_t *, struct iseq_link_anchor *, const void *);
    const void *data;
};
static inline struct rb_iseq_new_with_callback_callback_func *
rb_iseq_new_with_callback_new_callback(
    void (*func)(rb_iseq_t *, struct iseq_link_anchor *, const void *), const void *ptr)
{
    VALUE memo = rb_imemo_new(imemo_ifunc, (VALUE)func, (VALUE)ptr, Qundef, Qfalse);
    return (struct rb_iseq_new_with_callback_callback_func *)memo;
}
rb_iseq_t *rb_iseq_new_with_callback(const struct rb_iseq_new_with_callback_callback_func * ifunc,
    VALUE name, VALUE path, VALUE realpath, VALUE first_lineno,
    const rb_iseq_t *parent, enum iseq_type, const rb_compile_option_t*);

VALUE rb_iseq_disasm(const rb_iseq_t *iseq);
int rb_iseq_disasm_insn(VALUE str, const VALUE *iseqval, size_t pos, const rb_iseq_t *iseq, VALUE child);

VALUE rb_iseq_coverage(const rb_iseq_t *iseq);

RUBY_EXTERN VALUE rb_cISeq;
RUBY_EXTERN VALUE rb_cRubyVM;
RUBY_EXTERN VALUE rb_mRubyVMFrozenCore;
RUBY_EXTERN VALUE rb_block_param_proxy;
RUBY_SYMBOL_EXPORT_END

#define GetProcPtr(obj, ptr) \
  GetCoreDataFromValue((obj), rb_proc_t, (ptr))

typedef struct {
    const struct rb_block block;
    unsigned int is_from_method: 1;	/* bool */
    unsigned int is_lambda: 1;		/* bool */
    unsigned int is_isolated: 1;        /* bool */
} rb_proc_t;

VALUE rb_proc_isolate(VALUE self);
VALUE rb_proc_isolate_bang(VALUE self);
VALUE rb_proc_ractor_make_shareable(VALUE self);

typedef struct {
    VALUE flags; /* imemo header */
    rb_iseq_t *iseq;
    const VALUE *ep;
    const VALUE *env;
    unsigned int env_size;
} rb_env_t;

extern const rb_data_type_t ruby_binding_data_type;

#define GetBindingPtr(obj, ptr) \
  GetCoreDataFromValue((obj), rb_binding_t, (ptr))

typedef struct {
    const struct rb_block block;
    const VALUE pathobj;
    unsigned short first_lineno;
} rb_binding_t;

/* used by compile time and send insn */

enum vm_check_match_type {
    VM_CHECKMATCH_TYPE_WHEN = 1,
    VM_CHECKMATCH_TYPE_CASE = 2,
    VM_CHECKMATCH_TYPE_RESCUE = 3
};

#define VM_CHECKMATCH_TYPE_MASK   0x03
#define VM_CHECKMATCH_ARRAY       0x04

enum vm_special_object_type {
    VM_SPECIAL_OBJECT_VMCORE = 1,
    VM_SPECIAL_OBJECT_CBASE,
    VM_SPECIAL_OBJECT_CONST_BASE
};

enum vm_svar_index {
    VM_SVAR_LASTLINE = 0,      /* $_ */
    VM_SVAR_BACKREF = 1,       /* $~ */

    VM_SVAR_EXTRA_START = 2,
    VM_SVAR_FLIPFLOP_START = 2 /* flipflop */
};

/* inline cache */
typedef struct iseq_inline_cache_entry *IC;
typedef struct iseq_inline_iv_cache_entry *IVC;
typedef union iseq_inline_storage_entry *ISE;
typedef const struct rb_callinfo *CALL_INFO;
typedef const struct rb_callcache *CALL_CACHE;
typedef struct rb_call_data *CALL_DATA;

typedef VALUE CDHASH;

#ifndef FUNC_FASTCALL
#define FUNC_FASTCALL(x) x
#endif

typedef rb_control_frame_t *
  (FUNC_FASTCALL(*rb_insn_func_t))(rb_execution_context_t *, rb_control_frame_t *);

#define VM_TAGGED_PTR_SET(p, tag)  ((VALUE)(p) | (tag))
#define VM_TAGGED_PTR_REF(v, mask) ((void *)((v) & ~mask))

#define GC_GUARDED_PTR(p)     VM_TAGGED_PTR_SET((p), 0x01)
#define GC_GUARDED_PTR_REF(p) VM_TAGGED_PTR_REF((p), 0x03)
#define GC_GUARDED_PTR_P(p)   (((VALUE)(p)) & 0x01)

enum {
    /* Frame/Environment flag bits:
     *   MMMM MMMM MMMM MMMM ____ _FFF FFFF EEEX (LSB)
     *
     * X   : tag for GC marking (It seems as Fixnum)
     * EEE : 3 bits Env flags
     * FF..: 7 bits Frame flags
     * MM..: 15 bits frame magic (to check frame corruption)
     */

    /* frame types */
    VM_FRAME_MAGIC_METHOD = 0x11110001,
    VM_FRAME_MAGIC_BLOCK  = 0x22220001,
    VM_FRAME_MAGIC_CLASS  = 0x33330001,
    VM_FRAME_MAGIC_TOP    = 0x44440001,
    VM_FRAME_MAGIC_CFUNC  = 0x55550001,
    VM_FRAME_MAGIC_IFUNC  = 0x66660001,
    VM_FRAME_MAGIC_EVAL   = 0x77770001,
    VM_FRAME_MAGIC_RESCUE = 0x78880001,
    VM_FRAME_MAGIC_DUMMY  = 0x79990001,

    VM_FRAME_MAGIC_MASK   = 0x7fff0001,

    /* frame flag */
    VM_FRAME_FLAG_FINISH    = 0x0020,
    VM_FRAME_FLAG_BMETHOD   = 0x0040,
    VM_FRAME_FLAG_CFRAME    = 0x0080,
    VM_FRAME_FLAG_LAMBDA    = 0x0100,
    VM_FRAME_FLAG_MODIFIED_BLOCK_PARAM = 0x0200,
    VM_FRAME_FLAG_CFRAME_KW = 0x0400,
    VM_FRAME_FLAG_PASSED    = 0x0800,

    /* env flag */
    VM_ENV_FLAG_LOCAL       = 0x0002,
    VM_ENV_FLAG_ESCAPED     = 0x0004,
    VM_ENV_FLAG_WB_REQUIRED = 0x0008,
    VM_ENV_FLAG_ISOLATED    = 0x0010,
};

#define VM_ENV_DATA_SIZE             ( 3)

#define VM_ENV_DATA_INDEX_ME_CREF    (-2) /* ep[-2] */
#define VM_ENV_DATA_INDEX_SPECVAL    (-1) /* ep[-1] */
#define VM_ENV_DATA_INDEX_FLAGS      ( 0) /* ep[ 0] */
#define VM_ENV_DATA_INDEX_ENV        ( 1) /* ep[ 1] */

#define VM_ENV_INDEX_LAST_LVAR              (-VM_ENV_DATA_SIZE)

static inline void VM_FORCE_WRITE_SPECIAL_CONST(const VALUE *ptr, VALUE special_const_value);

static inline void
VM_ENV_FLAGS_SET(const VALUE *ep, VALUE flag)
{
    VALUE flags = ep[VM_ENV_DATA_INDEX_FLAGS];
    VM_ASSERT(FIXNUM_P(flags));
    VM_FORCE_WRITE_SPECIAL_CONST(&ep[VM_ENV_DATA_INDEX_FLAGS], flags | flag);
}

static inline void
VM_ENV_FLAGS_UNSET(const VALUE *ep, VALUE flag)
{
    VALUE flags = ep[VM_ENV_DATA_INDEX_FLAGS];
    VM_ASSERT(FIXNUM_P(flags));
    VM_FORCE_WRITE_SPECIAL_CONST(&ep[VM_ENV_DATA_INDEX_FLAGS], flags & ~flag);
}

static inline unsigned long
VM_ENV_FLAGS(const VALUE *ep, long flag)
{
    VALUE flags = ep[VM_ENV_DATA_INDEX_FLAGS];
    VM_ASSERT(FIXNUM_P(flags));
    return flags & flag;
}

static inline unsigned long
VM_FRAME_TYPE(const rb_control_frame_t *cfp)
{
    return VM_ENV_FLAGS(cfp->ep, VM_FRAME_MAGIC_MASK);
}

static inline int
VM_FRAME_LAMBDA_P(const rb_control_frame_t *cfp)
{
    return VM_ENV_FLAGS(cfp->ep, VM_FRAME_FLAG_LAMBDA) != 0;
}

static inline int
VM_FRAME_CFRAME_KW_P(const rb_control_frame_t *cfp)
{
    return VM_ENV_FLAGS(cfp->ep, VM_FRAME_FLAG_CFRAME_KW) != 0;
}

static inline int
VM_FRAME_FINISHED_P(const rb_control_frame_t *cfp)
{
    return VM_ENV_FLAGS(cfp->ep, VM_FRAME_FLAG_FINISH) != 0;
}

static inline int
VM_FRAME_BMETHOD_P(const rb_control_frame_t *cfp)
{
    return VM_ENV_FLAGS(cfp->ep, VM_FRAME_FLAG_BMETHOD) != 0;
}

static inline int
rb_obj_is_iseq(VALUE iseq)
{
    return imemo_type_p(iseq, imemo_iseq);
}

#if VM_CHECK_MODE > 0
#define RUBY_VM_NORMAL_ISEQ_P(iseq)  rb_obj_is_iseq((VALUE)iseq)
#endif

static inline int
VM_FRAME_CFRAME_P(const rb_control_frame_t *cfp)
{
    int cframe_p = VM_ENV_FLAGS(cfp->ep, VM_FRAME_FLAG_CFRAME) != 0;
    VM_ASSERT(RUBY_VM_NORMAL_ISEQ_P(cfp->iseq) != cframe_p);
    return cframe_p;
}

static inline int
VM_FRAME_RUBYFRAME_P(const rb_control_frame_t *cfp)
{
    return !VM_FRAME_CFRAME_P(cfp);
}

#define RUBYVM_CFUNC_FRAME_P(cfp) \
  (VM_FRAME_TYPE(cfp) == VM_FRAME_MAGIC_CFUNC)

#define VM_GUARDED_PREV_EP(ep)         GC_GUARDED_PTR(ep)
#define VM_BLOCK_HANDLER_NONE 0

static inline int
VM_ENV_LOCAL_P(const VALUE *ep)
{
    return VM_ENV_FLAGS(ep, VM_ENV_FLAG_LOCAL) ? 1 : 0;
}

static inline const VALUE *
VM_ENV_PREV_EP(const VALUE *ep)
{
    VM_ASSERT(VM_ENV_LOCAL_P(ep) == 0);
    return GC_GUARDED_PTR_REF(ep[VM_ENV_DATA_INDEX_SPECVAL]);
}

static inline VALUE
VM_ENV_BLOCK_HANDLER(const VALUE *ep)
{
    VM_ASSERT(VM_ENV_LOCAL_P(ep));
    return ep[VM_ENV_DATA_INDEX_SPECVAL];
}

#if VM_CHECK_MODE > 0
int rb_vm_ep_in_heap_p(const VALUE *ep);
#endif

static inline int
VM_ENV_ESCAPED_P(const VALUE *ep)
{
    VM_ASSERT(rb_vm_ep_in_heap_p(ep) == !!VM_ENV_FLAGS(ep, VM_ENV_FLAG_ESCAPED));
    return VM_ENV_FLAGS(ep, VM_ENV_FLAG_ESCAPED) ? 1 : 0;
}

#if VM_CHECK_MODE > 0
static inline int
vm_assert_env(VALUE obj)
{
    VM_ASSERT(imemo_type_p(obj, imemo_env));
    return 1;
}
#endif

static inline VALUE
VM_ENV_ENVVAL(const VALUE *ep)
{
    VALUE envval = ep[VM_ENV_DATA_INDEX_ENV];
    VM_ASSERT(VM_ENV_ESCAPED_P(ep));
    VM_ASSERT(vm_assert_env(envval));
    return envval;
}

static inline const rb_env_t *
VM_ENV_ENVVAL_PTR(const VALUE *ep)
{
    return (const rb_env_t *)VM_ENV_ENVVAL(ep);
}

static inline const rb_env_t *
vm_env_new(VALUE *env_ep, VALUE *env_body, unsigned int env_size, const rb_iseq_t *iseq)
{
    rb_env_t *env = (rb_env_t *)rb_imemo_new(imemo_env, (VALUE)env_ep, (VALUE)env_body, 0, (VALUE)iseq);
    env->env_size = env_size;
    env_ep[VM_ENV_DATA_INDEX_ENV] = (VALUE)env;
    return env;
}

static inline void
VM_FORCE_WRITE(const VALUE *ptr, VALUE v)
{
    *((VALUE *)ptr) = v;
}

static inline void
VM_FORCE_WRITE_SPECIAL_CONST(const VALUE *ptr, VALUE special_const_value)
{
    VM_ASSERT(RB_SPECIAL_CONST_P(special_const_value));
    VM_FORCE_WRITE(ptr, special_const_value);
}

static inline void
VM_STACK_ENV_WRITE(const VALUE *ep, int index, VALUE v)
{
    VM_ASSERT(VM_ENV_FLAGS(ep, VM_ENV_FLAG_WB_REQUIRED) == 0);
    VM_FORCE_WRITE(&ep[index], v);
}

const VALUE *rb_vm_ep_local_ep(const VALUE *ep);
const VALUE *rb_vm_proc_local_ep(VALUE proc);
void rb_vm_block_ep_update(VALUE obj, const struct rb_block *dst, const VALUE *ep);
void rb_vm_block_copy(VALUE obj, const struct rb_block *dst, const struct rb_block *src);

VALUE rb_vm_frame_block_handler(const rb_control_frame_t *cfp);

#define RUBY_VM_PREVIOUS_CONTROL_FRAME(cfp) ((cfp)+1)
#define RUBY_VM_NEXT_CONTROL_FRAME(cfp) ((cfp)-1)

#define RUBY_VM_VALID_CONTROL_FRAME_P(cfp, ecfp) \
  ((void *)(ecfp) > (void *)(cfp))

static inline const rb_control_frame_t *
RUBY_VM_END_CONTROL_FRAME(const rb_execution_context_t *ec)
{
    return (rb_control_frame_t *)(ec->vm_stack + ec->vm_stack_size);
}

static inline int
RUBY_VM_CONTROL_FRAME_STACK_OVERFLOW_P(const rb_execution_context_t *ec, const rb_control_frame_t *cfp)
{
    return !RUBY_VM_VALID_CONTROL_FRAME_P(cfp, RUBY_VM_END_CONTROL_FRAME(ec));
}

static inline int
VM_BH_ISEQ_BLOCK_P(VALUE block_handler)
{
    if ((block_handler & 0x03) == 0x01) {
#if VM_CHECK_MODE > 0
	struct rb_captured_block *captured = VM_TAGGED_PTR_REF(block_handler, 0x03);
	VM_ASSERT(imemo_type_p(captured->code.val, imemo_iseq));
#endif
	return 1;
    }
    else {
	return 0;
    }
}

static inline VALUE
VM_BH_FROM_ISEQ_BLOCK(const struct rb_captured_block *captured)
{
    VALUE block_handler = VM_TAGGED_PTR_SET(captured, 0x01);
    VM_ASSERT(VM_BH_ISEQ_BLOCK_P(block_handler));
    return block_handler;
}

static inline const struct rb_captured_block *
VM_BH_TO_ISEQ_BLOCK(VALUE block_handler)
{
    struct rb_captured_block *captured = VM_TAGGED_PTR_REF(block_handler, 0x03);
    VM_ASSERT(VM_BH_ISEQ_BLOCK_P(block_handler));
    return captured;
}

static inline int
VM_BH_IFUNC_P(VALUE block_handler)
{
    if ((block_handler & 0x03) == 0x03) {
#if VM_CHECK_MODE > 0
	struct rb_captured_block *captured = (void *)(block_handler & ~0x03);
	VM_ASSERT(imemo_type_p(captured->code.val, imemo_ifunc));
#endif
	return 1;
    }
    else {
	return 0;
    }
}

static inline VALUE
VM_BH_FROM_IFUNC_BLOCK(const struct rb_captured_block *captured)
{
    VALUE block_handler = VM_TAGGED_PTR_SET(captured, 0x03);
    VM_ASSERT(VM_BH_IFUNC_P(block_handler));
    return block_handler;
}

static inline const struct rb_captured_block *
VM_BH_TO_IFUNC_BLOCK(VALUE block_handler)
{
    struct rb_captured_block *captured = VM_TAGGED_PTR_REF(block_handler, 0x03);
    VM_ASSERT(VM_BH_IFUNC_P(block_handler));
    return captured;
}

static inline const struct rb_captured_block *
VM_BH_TO_CAPT_BLOCK(VALUE block_handler)
{
    struct rb_captured_block *captured = VM_TAGGED_PTR_REF(block_handler, 0x03);
    VM_ASSERT(VM_BH_IFUNC_P(block_handler) || VM_BH_ISEQ_BLOCK_P(block_handler));
    return captured;
}

static inline enum rb_block_handler_type
vm_block_handler_type(VALUE block_handler)
{
    if (VM_BH_ISEQ_BLOCK_P(block_handler)) {
	return block_handler_type_iseq;
    }
    else if (VM_BH_IFUNC_P(block_handler)) {
	return block_handler_type_ifunc;
    }
    else if (SYMBOL_P(block_handler)) {
	return block_handler_type_symbol;
    }
    else {
	VM_ASSERT(rb_obj_is_proc(block_handler));
	return block_handler_type_proc;
    }
}

static inline void
vm_block_handler_verify(MAYBE_UNUSED(VALUE block_handler))
{
    VM_ASSERT(block_handler == VM_BLOCK_HANDLER_NONE ||
	      (vm_block_handler_type(block_handler), 1));
}

static inline int
vm_cfp_forwarded_bh_p(const rb_control_frame_t *cfp, VALUE block_handler)
{
    return ((VALUE) cfp->block_code) == block_handler;
}

static inline enum rb_block_type
vm_block_type(const struct rb_block *block)
{
#if VM_CHECK_MODE > 0
    switch (block->type) {
      case block_type_iseq:
	VM_ASSERT(imemo_type_p(block->as.captured.code.val, imemo_iseq));
	break;
      case block_type_ifunc:
	VM_ASSERT(imemo_type_p(block->as.captured.code.val, imemo_ifunc));
	break;
      case block_type_symbol:
	VM_ASSERT(SYMBOL_P(block->as.symbol));
	break;
      case block_type_proc:
	VM_ASSERT(rb_obj_is_proc(block->as.proc));
	break;
    }
#endif
    return block->type;
}

static inline void
vm_block_type_set(const struct rb_block *block, enum rb_block_type type)
{
    struct rb_block *mb = (struct rb_block *)block;
    mb->type = type;
}

static inline const struct rb_block *
vm_proc_block(VALUE procval)
{
    VM_ASSERT(rb_obj_is_proc(procval));
    return &((rb_proc_t *)RTYPEDDATA_DATA(procval))->block;
}

static inline const rb_iseq_t *vm_block_iseq(const struct rb_block *block);
static inline const VALUE *vm_block_ep(const struct rb_block *block);

static inline const rb_iseq_t *
vm_proc_iseq(VALUE procval)
{
    return vm_block_iseq(vm_proc_block(procval));
}

static inline const VALUE *
vm_proc_ep(VALUE procval)
{
    return vm_block_ep(vm_proc_block(procval));
}

static inline const rb_iseq_t *
vm_block_iseq(const struct rb_block *block)
{
    switch (vm_block_type(block)) {
      case block_type_iseq: return rb_iseq_check(block->as.captured.code.iseq);
      case block_type_proc: return vm_proc_iseq(block->as.proc);
      case block_type_ifunc:
      case block_type_symbol: return NULL;
    }
    VM_UNREACHABLE(vm_block_iseq);
    return NULL;
}

static inline const VALUE *
vm_block_ep(const struct rb_block *block)
{
    switch (vm_block_type(block)) {
      case block_type_iseq:
      case block_type_ifunc:  return block->as.captured.ep;
      case block_type_proc:   return vm_proc_ep(block->as.proc);
      case block_type_symbol: return NULL;
    }
    VM_UNREACHABLE(vm_block_ep);
    return NULL;
}

static inline VALUE
vm_block_self(const struct rb_block *block)
{
    switch (vm_block_type(block)) {
      case block_type_iseq:
      case block_type_ifunc:
	return block->as.captured.self;
      case block_type_proc:
	return vm_block_self(vm_proc_block(block->as.proc));
      case block_type_symbol:
	return Qundef;
    }
    VM_UNREACHABLE(vm_block_self);
    return Qundef;
}

static inline VALUE
VM_BH_TO_SYMBOL(VALUE block_handler)
{
    VM_ASSERT(SYMBOL_P(block_handler));
    return block_handler;
}

static inline VALUE
VM_BH_FROM_SYMBOL(VALUE symbol)
{
    VM_ASSERT(SYMBOL_P(symbol));
    return symbol;
}

static inline VALUE
VM_BH_TO_PROC(VALUE block_handler)
{
    VM_ASSERT(rb_obj_is_proc(block_handler));
    return block_handler;
}

static inline VALUE
VM_BH_FROM_PROC(VALUE procval)
{
    VM_ASSERT(rb_obj_is_proc(procval));
    return procval;
}

/* VM related object allocate functions */
VALUE rb_thread_alloc(VALUE klass);
VALUE rb_binding_alloc(VALUE klass);
VALUE rb_proc_alloc(VALUE klass);
VALUE rb_proc_dup(VALUE self);

/* for debug */
extern void rb_vmdebug_stack_dump_raw(const rb_execution_context_t *ec, const rb_control_frame_t *cfp);
extern void rb_vmdebug_debug_print_pre(const rb_execution_context_t *ec, const rb_control_frame_t *cfp, const VALUE *_pc);
extern void rb_vmdebug_debug_print_post(const rb_execution_context_t *ec, const rb_control_frame_t *cfp
#if OPT_STACK_CACHING
    , VALUE reg_a, VALUE reg_b
#endif
);

#define SDR() rb_vmdebug_stack_dump_raw(GET_EC(), GET_EC()->cfp)
#define SDR2(cfp) rb_vmdebug_stack_dump_raw(GET_EC(), (cfp))
void rb_vm_bugreport(const void *);
typedef void (*ruby_sighandler_t)(int);
NORETURN(void rb_bug_for_fatal_signal(ruby_sighandler_t default_sighandler, int sig, const void *, const char *fmt, ...));

/* functions about thread/vm execution */
RUBY_SYMBOL_EXPORT_BEGIN
VALUE rb_iseq_eval(const rb_iseq_t *iseq);
VALUE rb_iseq_eval_main(const rb_iseq_t *iseq);
VALUE rb_iseq_path(const rb_iseq_t *iseq);
VALUE rb_iseq_realpath(const rb_iseq_t *iseq);
RUBY_SYMBOL_EXPORT_END

VALUE rb_iseq_pathobj_new(VALUE path, VALUE realpath);
void rb_iseq_pathobj_set(const rb_iseq_t *iseq, VALUE path, VALUE realpath);

int rb_ec_frame_method_id_and_class(const rb_execution_context_t *ec, ID *idp, ID *called_idp, VALUE *klassp);
void rb_ec_setup_exception(const rb_execution_context_t *ec, VALUE mesg, VALUE cause);

VALUE rb_vm_invoke_proc(rb_execution_context_t *ec, rb_proc_t *proc, int argc, const VALUE *argv, int kw_splat, VALUE block_handler);

VALUE rb_vm_make_proc_lambda(const rb_execution_context_t *ec, const struct rb_captured_block *captured, VALUE klass, int8_t is_lambda);
static inline VALUE
rb_vm_make_proc(const rb_execution_context_t *ec, const struct rb_captured_block *captured, VALUE klass)
{
    return rb_vm_make_proc_lambda(ec, captured, klass, 0);
}

static inline VALUE
rb_vm_make_lambda(const rb_execution_context_t *ec, const struct rb_captured_block *captured, VALUE klass)
{
    return rb_vm_make_proc_lambda(ec, captured, klass, 1);
}

VALUE rb_vm_make_binding(const rb_execution_context_t *ec, const rb_control_frame_t *src_cfp);
VALUE rb_vm_env_local_variables(const rb_env_t *env);
const rb_env_t *rb_vm_env_prev_env(const rb_env_t *env);
const VALUE *rb_binding_add_dynavars(VALUE bindval, rb_binding_t *bind, int dyncount, const ID *dynvars);
void rb_vm_inc_const_missing_count(void);
VALUE rb_vm_call_kw(rb_execution_context_t *ec, VALUE recv, VALUE id, int argc,
                 const VALUE *argv, const rb_callable_method_entry_t *me, int kw_splat);
MJIT_STATIC void rb_vm_pop_frame(rb_execution_context_t *ec);

void rb_gvl_destroy(rb_global_vm_lock_t *gvl);

void rb_thread_start_timer_thread(void);
void rb_thread_stop_timer_thread(void);
void rb_thread_reset_timer_thread(void);
void rb_thread_wakeup_timer_thread(int);

static inline void
rb_vm_living_threads_init(rb_vm_t *vm)
{
    list_head_init(&vm->waiting_fds);
    list_head_init(&vm->waiting_pids);
    list_head_init(&vm->workqueue);
    list_head_init(&vm->waiting_grps);
    list_head_init(&vm->ractor.set);
}

typedef int rb_backtrace_iter_func(void *, VALUE, int, VALUE);
rb_control_frame_t *rb_vm_get_ruby_level_next_cfp(const rb_execution_context_t *ec, const rb_control_frame_t *cfp);
rb_control_frame_t *rb_vm_get_binding_creatable_next_cfp(const rb_execution_context_t *ec, const rb_control_frame_t *cfp);
int rb_vm_get_sourceline(const rb_control_frame_t *);
void rb_vm_stack_to_heap(rb_execution_context_t *ec);
void ruby_thread_init_stack(rb_thread_t *th);
int rb_vm_control_frame_id_and_class(const rb_control_frame_t *cfp, ID *idp, ID *called_idp, VALUE *klassp);
void rb_vm_rewind_cfp(rb_execution_context_t *ec, rb_control_frame_t *cfp);
MJIT_STATIC VALUE rb_vm_bh_to_procval(const rb_execution_context_t *ec, VALUE block_handler);

void rb_vm_register_special_exception_str(enum ruby_special_exceptions sp, VALUE exception_class, VALUE mesg);

#define rb_vm_register_special_exception(sp, e, m) \
    rb_vm_register_special_exception_str(sp, e, rb_usascii_str_new_static((m), (long)rb_strlen_lit(m)))

void rb_gc_mark_machine_stack(const rb_execution_context_t *ec);

void rb_vm_rewrite_cref(rb_cref_t *node, VALUE old_klass, VALUE new_klass, rb_cref_t **new_cref_ptr);

MJIT_STATIC const rb_callable_method_entry_t *rb_vm_frame_method_entry(const rb_control_frame_t *cfp);

#define sysstack_error GET_VM()->special_exceptions[ruby_error_sysstack]

#define CHECK_VM_STACK_OVERFLOW0(cfp, sp, margin) do {                       \
    STATIC_ASSERT(sizeof_sp,  sizeof(*(sp))  == sizeof(VALUE));              \
    STATIC_ASSERT(sizeof_cfp, sizeof(*(cfp)) == sizeof(rb_control_frame_t)); \
    const struct rb_control_frame_struct *bound = (void *)&(sp)[(margin)];   \
    if (UNLIKELY((cfp) <= &bound[1])) {                                      \
        vm_stackoverflow();                                                  \
    }                                                                        \
} while (0)

#define CHECK_VM_STACK_OVERFLOW(cfp, margin) \
    CHECK_VM_STACK_OVERFLOW0((cfp), (cfp)->sp, (margin))

VALUE rb_catch_protect(VALUE t, rb_block_call_func *func, VALUE data, enum ruby_tag_type *stateptr);

rb_execution_context_t *rb_vm_main_ractor_ec(rb_vm_t *vm); // ractor.c

/* for thread */

#if RUBY_VM_THREAD_MODEL == 2
RUBY_SYMBOL_EXPORT_BEGIN

RUBY_EXTERN struct rb_ractor_struct *ruby_single_main_ractor; // ractor.c
RUBY_EXTERN rb_vm_t *ruby_current_vm_ptr;
RUBY_EXTERN rb_event_flag_t ruby_vm_event_flags;
RUBY_EXTERN rb_event_flag_t ruby_vm_event_enabled_global_flags;
RUBY_EXTERN unsigned int    ruby_vm_event_local_num;

RUBY_SYMBOL_EXPORT_END

#define GET_VM()     rb_current_vm()
#define GET_RACTOR() rb_current_ractor()
#define GET_THREAD() rb_current_thread()
#define GET_EC()     rb_current_execution_context()

static inline rb_thread_t *
rb_ec_thread_ptr(const rb_execution_context_t *ec)
{
    return ec->thread_ptr;
}

static inline rb_ractor_t *
rb_ec_ractor_ptr(const rb_execution_context_t *ec)
{
    const rb_thread_t *th = rb_ec_thread_ptr(ec);
    if (th) {
        VM_ASSERT(th->ractor != NULL);
	return th->ractor;
    }
    else {
        return NULL;
    }
}

static inline rb_vm_t *
rb_ec_vm_ptr(const rb_execution_context_t *ec)
{
    const rb_thread_t *th = rb_ec_thread_ptr(ec);
    if (th) {
	return th->vm;
    }
    else {
	return NULL;
    }
}

static inline rb_execution_context_t *
rb_current_execution_context(void)
{
#ifdef RB_THREAD_LOCAL_SPECIFIER
  #if __APPLE__
    rb_execution_context_t *ec = rb_current_ec();
  #else
    rb_execution_context_t *ec = ruby_current_ec;
  #endif
#else
    rb_execution_context_t *ec = native_tls_get(ruby_current_ec_key);
#endif
    VM_ASSERT(ec != NULL);
    return ec;
}

static inline rb_thread_t *
rb_current_thread(void)
{
    const rb_execution_context_t *ec = GET_EC();
    return rb_ec_thread_ptr(ec);
}

static inline rb_ractor_t *
rb_current_ractor(void)
{
    if (ruby_single_main_ractor) {
        return ruby_single_main_ractor;
    }
    else {
        const rb_execution_context_t *ec = GET_EC();
        return rb_ec_ractor_ptr(ec);
    }
}

static inline rb_vm_t *
rb_current_vm(void)
{
#if 0 // TODO: reconsider the assertions
    VM_ASSERT(ruby_current_vm_ptr == NULL ||
	      ruby_current_execution_context_ptr == NULL ||
	      rb_ec_thread_ptr(GET_EC()) == NULL ||
              rb_ec_thread_ptr(GET_EC())->status == THREAD_KILLED ||
	      rb_ec_vm_ptr(GET_EC()) == ruby_current_vm_ptr);
#endif

    return ruby_current_vm_ptr;
}

void rb_ec_vm_lock_rec_release(const rb_execution_context_t *ec,
                               unsigned int recorded_lock_rec,
                               unsigned int current_lock_rec);

static inline unsigned int
rb_ec_vm_lock_rec(const rb_execution_context_t *ec)
{
    rb_vm_t *vm = rb_ec_vm_ptr(ec);

    if (vm->ractor.sync.lock_owner != rb_ec_ractor_ptr(ec)) {
        return 0;
    }
    else {
        return vm->ractor.sync.lock_rec;
    }
}

#else
#error "unsupported thread model"
#endif

enum {
    TIMER_INTERRUPT_MASK         = 0x01,
    PENDING_INTERRUPT_MASK       = 0x02,
    POSTPONED_JOB_INTERRUPT_MASK = 0x04,
    TRAP_INTERRUPT_MASK	         = 0x08,
    TERMINATE_INTERRUPT_MASK     = 0x10,
    VM_BARRIER_INTERRUPT_MASK    = 0x20,
};

#define RUBY_VM_SET_TIMER_INTERRUPT(ec)		ATOMIC_OR((ec)->interrupt_flag, TIMER_INTERRUPT_MASK)
#define RUBY_VM_SET_INTERRUPT(ec)		ATOMIC_OR((ec)->interrupt_flag, PENDING_INTERRUPT_MASK)
#define RUBY_VM_SET_POSTPONED_JOB_INTERRUPT(ec)	ATOMIC_OR((ec)->interrupt_flag, POSTPONED_JOB_INTERRUPT_MASK)
#define RUBY_VM_SET_TRAP_INTERRUPT(ec)		ATOMIC_OR((ec)->interrupt_flag, TRAP_INTERRUPT_MASK)
#define RUBY_VM_SET_TERMINATE_INTERRUPT(ec)     ATOMIC_OR((ec)->interrupt_flag, TERMINATE_INTERRUPT_MASK)
#define RUBY_VM_SET_VM_BARRIER_INTERRUPT(ec)    ATOMIC_OR((ec)->interrupt_flag, VM_BARRIER_INTERRUPT_MASK)
#define RUBY_VM_INTERRUPTED(ec)			((ec)->interrupt_flag & ~(ec)->interrupt_mask & \
						 (PENDING_INTERRUPT_MASK|TRAP_INTERRUPT_MASK))

static inline bool
RUBY_VM_INTERRUPTED_ANY(rb_execution_context_t *ec)
{
#if USE_VM_CLOCK
    uint32_t current_clock = rb_ec_vm_ptr(ec)->clock;

    if (current_clock != ec->checked_clock) {
        ec->checked_clock = current_clock;
        RUBY_VM_SET_TIMER_INTERRUPT(ec);
    }
#endif
    return ec->interrupt_flag & ~(ec)->interrupt_mask;
}

VALUE rb_exc_set_backtrace(VALUE exc, VALUE bt);
int rb_signal_buff_size(void);
int rb_signal_exec(rb_thread_t *th, int sig);
void rb_threadptr_check_signal(rb_thread_t *mth);
void rb_threadptr_signal_raise(rb_thread_t *th, int sig);
void rb_threadptr_signal_exit(rb_thread_t *th);
int rb_threadptr_execute_interrupts(rb_thread_t *, int);
void rb_threadptr_interrupt(rb_thread_t *th);
void rb_threadptr_unlock_all_locking_mutexes(rb_thread_t *th);
void rb_threadptr_pending_interrupt_clear(rb_thread_t *th);
void rb_threadptr_pending_interrupt_enque(rb_thread_t *th, VALUE v);
VALUE rb_ec_get_errinfo(const rb_execution_context_t *ec);
void rb_ec_error_print(rb_execution_context_t * volatile ec, volatile VALUE errinfo);
void rb_execution_context_update(const rb_execution_context_t *ec);
void rb_execution_context_mark(const rb_execution_context_t *ec);
void rb_fiber_close(rb_fiber_t *fib);
void Init_native_thread(rb_thread_t *th);
int rb_vm_check_ints_blocking(rb_execution_context_t *ec);

// vm_sync.h
void rb_vm_cond_wait(rb_vm_t *vm, rb_nativethread_cond_t *cond);
void rb_vm_cond_timedwait(rb_vm_t *vm, rb_nativethread_cond_t *cond, unsigned long msec);

#define RUBY_VM_CHECK_INTS(ec) rb_vm_check_ints(ec)
static inline void
rb_vm_check_ints(rb_execution_context_t *ec)
{
    VM_ASSERT(ec == GET_EC());
    if (UNLIKELY(RUBY_VM_INTERRUPTED_ANY(ec))) {
	rb_threadptr_execute_interrupts(rb_ec_thread_ptr(ec), 0);
    }
}

/* tracer */

struct rb_trace_arg_struct {
    rb_event_flag_t event;
    rb_execution_context_t *ec;
    const rb_control_frame_t *cfp;
    VALUE self;
    ID id;
    ID called_id;
    VALUE klass;
    VALUE data;

    int klass_solved;

    /* calc from cfp */
    int lineno;
    VALUE path;
};

void rb_hook_list_mark(rb_hook_list_t *hooks);
void rb_hook_list_free(rb_hook_list_t *hooks);
void rb_hook_list_connect_tracepoint(VALUE target, rb_hook_list_t *list, VALUE tpval, unsigned int target_line);
void rb_hook_list_remove_tracepoint(rb_hook_list_t *list, VALUE tpval);

void rb_exec_event_hooks(struct rb_trace_arg_struct *trace_arg, rb_hook_list_t *hooks, int pop_p);

#define EXEC_EVENT_HOOK_ORIG(ec_, hooks_, flag_, self_, id_, called_id_, klass_, data_, pop_p_) do { \
    const rb_event_flag_t flag_arg_ = (flag_); \
    rb_hook_list_t *hooks_arg_ = (hooks_); \
    if (UNLIKELY((hooks_arg_)->events & (flag_arg_))) { \
        /* defer evaluating the other arguments */ \
        rb_exec_event_hook_orig(ec_, hooks_arg_, flag_arg_, self_, id_, called_id_, klass_, data_, pop_p_); \
    } \
} while (0)

static inline void
rb_exec_event_hook_orig(rb_execution_context_t *ec, rb_hook_list_t *hooks, rb_event_flag_t flag,
                        VALUE self, ID id, ID called_id, VALUE klass, VALUE data, int pop_p)
{
    struct rb_trace_arg_struct trace_arg;

    VM_ASSERT((hooks->events & flag) != 0);

    trace_arg.event = flag;
    trace_arg.ec = ec;
    trace_arg.cfp = ec->cfp;
    trace_arg.self = self;
    trace_arg.id = id;
    trace_arg.called_id = called_id;
    trace_arg.klass = klass;
    trace_arg.data = data;
    trace_arg.path = Qundef;
    trace_arg.klass_solved = 0;

    rb_exec_event_hooks(&trace_arg, hooks, pop_p);
}

static inline rb_hook_list_t *
rb_vm_global_hooks(const rb_execution_context_t *ec)
{
    return &rb_ec_vm_ptr(ec)->global_hooks;
}

#define EXEC_EVENT_HOOK(ec_, flag_, self_, id_, called_id_, klass_, data_) \
  EXEC_EVENT_HOOK_ORIG(ec_, rb_vm_global_hooks(ec_), flag_, self_, id_, called_id_, klass_, data_, 0)

#define EXEC_EVENT_HOOK_AND_POP_FRAME(ec_, flag_, self_, id_, called_id_, klass_, data_) \
  EXEC_EVENT_HOOK_ORIG(ec_, rb_vm_global_hooks(ec_), flag_, self_, id_, called_id_, klass_, data_, 1)

static inline void
rb_exec_event_hook_script_compiled(rb_execution_context_t *ec, const rb_iseq_t *iseq, VALUE eval_script)
{
    EXEC_EVENT_HOOK(ec, RUBY_EVENT_SCRIPT_COMPILED, ec->cfp->self, 0, 0, 0,
                    NIL_P(eval_script) ? (VALUE)iseq :
                    rb_ary_new_from_args(2, eval_script, (VALUE)iseq));
}

void rb_vm_trap_exit(rb_vm_t *vm);

RUBY_SYMBOL_EXPORT_BEGIN

int rb_thread_check_trap_pending(void);

/* #define RUBY_EVENT_RESERVED_FOR_INTERNAL_USE 0x030000 */ /* from vm_core.h */
#define RUBY_EVENT_COVERAGE_LINE                0x010000
#define RUBY_EVENT_COVERAGE_BRANCH              0x020000

extern VALUE rb_get_coverages(void);
extern void rb_set_coverages(VALUE, int, VALUE);
extern void rb_clear_coverages(void);
extern void rb_reset_coverages(void);

void rb_postponed_job_flush(rb_vm_t *vm);

extern VALUE rb_eRactorUnsafeError; // ractor.c

RUBY_SYMBOL_EXPORT_END

#endif /* RUBY_VM_CORE_H */