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cosmopolitan/third_party/duktape/duk_hthread.h

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/*
* Heap thread object representation.
*
* duk_hthread is also the 'context' for public API functions via a
* different typedef. Most API calls operate on the topmost frame
* of the value stack only.
*/
#if !defined(DUK_HTHREAD_H_INCLUDED)
#define DUK_HTHREAD_H_INCLUDED
/*
* Stack constants
*/
/* Initial valstack size, roughly 0.7kiB. */
#define DUK_VALSTACK_INITIAL_SIZE 96U
/* Internal extra elements assumed on function entry, always added to
* user-defined 'extra' for e.g. the duk_check_stack() call.
*/
#define DUK_VALSTACK_INTERNAL_EXTRA 32U
/* Number of elements guaranteed to be user accessible (in addition to call
* arguments) on Duktape/C function entry. This is the major public API
* commitment.
*/
#define DUK_VALSTACK_API_ENTRY_MINIMUM DUK_API_ENTRY_STACK
/*
* Activation defines
*/
#define DUK_ACT_FLAG_STRICT (1U << 0) /* function executes in strict mode */
#define DUK_ACT_FLAG_TAILCALLED (1U << 1) /* activation has tail called one or more times */
#define DUK_ACT_FLAG_CONSTRUCT (1U << 2) /* function executes as a constructor (called via "new") */
#define DUK_ACT_FLAG_PREVENT_YIELD (1U << 3) /* activation prevents yield (native call or "new") */
#define DUK_ACT_FLAG_DIRECT_EVAL (1U << 4) /* activation is a direct eval call */
#define DUK_ACT_FLAG_CONSTRUCT_PROXY (1U << 5) /* activation is for Proxy 'construct' call, special return value handling */
#define DUK_ACT_FLAG_BREAKPOINT_ACTIVE (1U << 6) /* activation has active breakpoint(s) */
#define DUK_ACT_GET_FUNC(act) ((act)->func)
/*
* Flags for __FILE__ / __LINE__ registered into tracedata
*/
#define DUK_TB_FLAG_NOBLAME_FILELINE (1U << 0) /* don't report __FILE__ / __LINE__ as fileName/lineNumber */
/*
* Catcher defines
*/
/* XXX: remove catcher type entirely */
/* flags field: LLLLLLFT, L = label (24 bits), F = flags (4 bits), T = type (4 bits) */
#define DUK_CAT_TYPE_MASK 0x0000000fUL
#define DUK_CAT_TYPE_BITS 4
#define DUK_CAT_LABEL_MASK 0xffffff00UL
#define DUK_CAT_LABEL_BITS 24
#define DUK_CAT_LABEL_SHIFT 8
#define DUK_CAT_FLAG_CATCH_ENABLED (1U << 4) /* catch part will catch */
#define DUK_CAT_FLAG_FINALLY_ENABLED (1U << 5) /* finally part will catch */
#define DUK_CAT_FLAG_CATCH_BINDING_ENABLED (1U << 6) /* request to create catch binding */
#define DUK_CAT_FLAG_LEXENV_ACTIVE (1U << 7) /* catch or with binding is currently active */
#define DUK_CAT_TYPE_UNKNOWN 0
#define DUK_CAT_TYPE_TCF 1
#define DUK_CAT_TYPE_LABEL 2
#define DUK_CAT_GET_TYPE(c) ((c)->flags & DUK_CAT_TYPE_MASK)
#define DUK_CAT_GET_LABEL(c) (((c)->flags & DUK_CAT_LABEL_MASK) >> DUK_CAT_LABEL_SHIFT)
#define DUK_CAT_HAS_CATCH_ENABLED(c) ((c)->flags & DUK_CAT_FLAG_CATCH_ENABLED)
#define DUK_CAT_HAS_FINALLY_ENABLED(c) ((c)->flags & DUK_CAT_FLAG_FINALLY_ENABLED)
#define DUK_CAT_HAS_CATCH_BINDING_ENABLED(c) ((c)->flags & DUK_CAT_FLAG_CATCH_BINDING_ENABLED)
#define DUK_CAT_HAS_LEXENV_ACTIVE(c) ((c)->flags & DUK_CAT_FLAG_LEXENV_ACTIVE)
#define DUK_CAT_SET_CATCH_ENABLED(c) do { \
(c)->flags |= DUK_CAT_FLAG_CATCH_ENABLED; \
} while (0)
#define DUK_CAT_SET_FINALLY_ENABLED(c) do { \
(c)->flags |= DUK_CAT_FLAG_FINALLY_ENABLED; \
} while (0)
#define DUK_CAT_SET_CATCH_BINDING_ENABLED(c) do { \
(c)->flags |= DUK_CAT_FLAG_CATCH_BINDING_ENABLED; \
} while (0)
#define DUK_CAT_SET_LEXENV_ACTIVE(c) do { \
(c)->flags |= DUK_CAT_FLAG_LEXENV_ACTIVE; \
} while (0)
#define DUK_CAT_CLEAR_CATCH_ENABLED(c) do { \
(c)->flags &= ~DUK_CAT_FLAG_CATCH_ENABLED; \
} while (0)
#define DUK_CAT_CLEAR_FINALLY_ENABLED(c) do { \
(c)->flags &= ~DUK_CAT_FLAG_FINALLY_ENABLED; \
} while (0)
#define DUK_CAT_CLEAR_CATCH_BINDING_ENABLED(c) do { \
(c)->flags &= ~DUK_CAT_FLAG_CATCH_BINDING_ENABLED; \
} while (0)
#define DUK_CAT_CLEAR_LEXENV_ACTIVE(c) do { \
(c)->flags &= ~DUK_CAT_FLAG_LEXENV_ACTIVE; \
} while (0)
/*
* Thread defines
*/
#if defined(DUK_USE_ROM_STRINGS)
#define DUK_HTHREAD_GET_STRING(thr,idx) \
((duk_hstring *) DUK_LOSE_CONST(duk_rom_strings_stridx[(idx)]))
#else /* DUK_USE_ROM_STRINGS */
#if defined(DUK_USE_HEAPPTR16)
#define DUK_HTHREAD_GET_STRING(thr,idx) \
((duk_hstring *) DUK_USE_HEAPPTR_DEC16((thr)->heap->heap_udata, (thr)->strs16[(idx)]))
#else
#define DUK_HTHREAD_GET_STRING(thr,idx) \
((thr)->strs[(idx)])
#endif
#endif /* DUK_USE_ROM_STRINGS */
/* values for the state field */
#define DUK_HTHREAD_STATE_INACTIVE 1 /* thread not currently running */
#define DUK_HTHREAD_STATE_RUNNING 2 /* thread currently running (only one at a time) */
#define DUK_HTHREAD_STATE_RESUMED 3 /* thread resumed another thread (active but not running) */
#define DUK_HTHREAD_STATE_YIELDED 4 /* thread has yielded */
#define DUK_HTHREAD_STATE_TERMINATED 5 /* thread has terminated */
/* Executor interrupt default interval when nothing else requires a
* smaller value. The default interval must be small enough to allow
* for reasonable execution timeout checking but large enough to keep
* impact on execution performance low.
*/
#if defined(DUK_USE_INTERRUPT_COUNTER)
#define DUK_HTHREAD_INTCTR_DEFAULT (256L * 1024L)
#endif
/*
* Assert context is valid: non-NULL pointer, fields look sane.
*
* This is used by public API call entrypoints to catch invalid 'ctx' pointers
* as early as possible; invalid 'ctx' pointers cause very odd and difficult to
* diagnose behavior so it's worth checking even when the check is not 100%.
*/
#if defined(DUK_USE_ASSERTIONS)
/* Assertions for internals. */
DUK_INTERNAL_DECL void duk_hthread_assert_valid(duk_hthread *thr);
#define DUK_HTHREAD_ASSERT_VALID(thr) do { duk_hthread_assert_valid((thr)); } while (0)
/* Assertions for public API calls; a bit stronger. */
DUK_INTERNAL_DECL void duk_ctx_assert_valid(duk_hthread *thr);
#define DUK_CTX_ASSERT_VALID(thr) do { duk_ctx_assert_valid((thr)); } while (0)
#else
#define DUK_HTHREAD_ASSERT_VALID(thr) do {} while (0)
#define DUK_CTX_ASSERT_VALID(thr) do {} while (0)
#endif
/* Assertions for API call entry specifically. Checks 'ctx' but also may
* check internal state (e.g. not in a debugger transport callback).
*/
#define DUK_ASSERT_API_ENTRY(thr) do { \
DUK_CTX_ASSERT_VALID((thr)); \
DUK_ASSERT((thr)->heap != NULL); \
DUK_ASSERT((thr)->heap->dbg_calling_transport == 0); \
} while (0)
/*
* Assertion helpers.
*/
#define DUK_ASSERT_STRIDX_VALID(val) \
DUK_ASSERT((duk_uint_t) (val) < DUK_HEAP_NUM_STRINGS)
#define DUK_ASSERT_BIDX_VALID(val) \
DUK_ASSERT((duk_uint_t) (val) < DUK_NUM_BUILTINS)
/*
* Misc
*/
/* Fast access to 'this' binding. Assumes there's a call in progress. */
#define DUK_HTHREAD_THIS_PTR(thr) \
(DUK_ASSERT_EXPR((thr) != NULL), \
DUK_ASSERT_EXPR((thr)->valstack_bottom > (thr)->valstack), \
(thr)->valstack_bottom - 1)
/*
* Struct defines
*/
/* Fields are ordered for alignment/packing. */
struct duk_activation {
duk_tval tv_func; /* borrowed: full duk_tval for function being executed; for lightfuncs */
duk_hobject *func; /* borrowed: function being executed; for bound function calls, this is the final, real function, NULL for lightfuncs */
duk_activation *parent; /* previous (parent) activation (or NULL if none) */
duk_hobject *var_env; /* current variable environment (may be NULL if delayed) */
duk_hobject *lex_env; /* current lexical environment (may be NULL if delayed) */
duk_catcher *cat; /* current catcher (or NULL) */
#if defined(DUK_USE_NONSTD_FUNC_CALLER_PROPERTY)
/* Previous value of 'func' caller, restored when unwound. Only in use
* when 'func' is non-strict.
*/
duk_hobject *prev_caller;
#endif
duk_instr_t *curr_pc; /* next instruction to execute (points to 'func' bytecode, stable pointer), NULL for native calls */
/* bottom_byteoff and retval_byteoff are only used for book-keeping
* of ECMAScript-initiated calls, to allow returning to an ECMAScript
* function properly.
*/
/* Bottom of valstack for this activation, used to reset
* valstack_bottom on return; offset is absolute. There's
* no need to track 'top' because native call handling deals
* with that using locals, and for ECMAScript returns 'nregs'
* indicates the necessary top.
*/
duk_size_t bottom_byteoff;
/* Return value when returning to this activation (points to caller
* reg, not callee reg); offset is absolute (only set if activation is
* not topmost).
*
* Note: bottom_byteoff is always set, while retval_byteoff is only
* applicable for activations below the topmost one. Currently
* retval_byteoff for the topmost activation is considered garbage
* (and it not initialized on entry or cleared on return; may contain
* previous or garbage values).
*/
duk_size_t retval_byteoff;
/* Current 'this' binding is the value just below bottom.
* Previously, 'this' binding was handled with an index to the
* (calling) valstack. This works for everything except tail
* calls, which must not "accumulate" valstack temps.
*/
/* Value stack reserve (valstack_end) byte offset to be restored
* when returning to this activation. Only used by the bytecode
* executor.
*/
duk_size_t reserve_byteoff;
#if defined(DUK_USE_DEBUGGER_SUPPORT)
duk_uint32_t prev_line; /* needed for stepping */
#endif
duk_small_uint_t flags;
};
struct duk_catcher {
duk_catcher *parent; /* previous (parent) catcher (or NULL if none) */
duk_hstring *h_varname; /* borrowed reference to catch variable name (or NULL if none) */
/* (reference is valid as long activation exists) */
duk_instr_t *pc_base; /* resume execution from pc_base or pc_base+1 (points to 'func' bytecode, stable pointer) */
duk_size_t idx_base; /* idx_base and idx_base+1 get completion value and type */
duk_uint32_t flags; /* type and control flags, label number */
/* XXX: could pack 'flags' and 'idx_base' to same value in practice,
* on 32-bit targets this would make duk_catcher 16 bytes.
*/
};
struct duk_hthread {
/* Shared object part */
duk_hobject obj;
/* Pointer to bytecode executor's 'curr_pc' variable. Used to copy
* the current PC back into the topmost activation when activation
* state is about to change (or "syncing" is otherwise needed). This
* is rather awkward but important for performance, see execution.rst.
*/
duk_instr_t **ptr_curr_pc;
/* Backpointers. */
duk_heap *heap;
/* Current strictness flag: affects API calls. */
duk_uint8_t strict;
/* Thread state. */
duk_uint8_t state;
duk_uint8_t unused1;
duk_uint8_t unused2;
/* XXX: Valstack and callstack are currently assumed to have non-NULL
* pointers. Relaxing this would not lead to big benefits (except
* perhaps for terminated threads).
*/
/* Value stack: these are expressed as pointers for faster stack
* manipulation. [valstack,valstack_top[ is GC-reachable,
* [valstack_top,valstack_alloc_end[ is not GC-reachable but kept
* initialized as 'undefined'. [valstack,valstack_end[ is the
* guaranteed/reserved space and the valstack cannot be resized to
* a smaller size. [valstack_end,valstack_alloc_end[ is currently
* allocated slack that can be used to grow the current guaranteed
* space but may be shrunk away without notice.
*
*
* <----------------------- guaranteed --->
* <---- slack --->
* <--- frame --->
* .-------------+=============+----------+--------------.
* |xxxxxxxxxxxxx|yyyyyyyyyyyyy|uuuuuuuuuu|uuuuuuuuuuuuuu|
* `-------------+=============+----------+--------------'
*
* ^ ^ ^ ^ ^
* | | | | |
* valstack bottom top end alloc_end
*
* xxx = arbitrary values, below current frame
* yyy = arbitrary values, inside current frame
* uuu = outside active value stack, initialized to 'undefined'
*/
duk_tval *valstack; /* start of valstack allocation */
duk_tval *valstack_end; /* end of valstack reservation/guarantee (exclusive) */
duk_tval *valstack_alloc_end; /* end of valstack allocation */
duk_tval *valstack_bottom; /* bottom of current frame */
duk_tval *valstack_top; /* top of current frame (exclusive) */
/* Call stack, represented as a linked list starting from the current
* activation (or NULL if nothing is active).
*/
duk_activation *callstack_curr; /* current activation (or NULL if none) */
duk_size_t callstack_top; /* number of activation records in callstack (0 if none) */
duk_size_t callstack_preventcount; /* number of activation records in callstack preventing a yield */
/* Yield/resume book-keeping. */
duk_hthread *resumer; /* who resumed us (if any) */
/* Current compiler state (if any), used for augmenting SyntaxErrors. */
duk_compiler_ctx *compile_ctx;
#if defined(DUK_USE_INTERRUPT_COUNTER)
/* Interrupt counter for triggering a slow path check for execution
* timeout, debugger interaction such as breakpoints, etc. The value
* is valid for the current running thread, and both the init and
* counter values are copied whenever a thread switch occurs. It's
* important for the counter to be conveniently accessible for the
* bytecode executor inner loop for performance reasons.
*/
duk_int_t interrupt_counter; /* countdown state */
duk_int_t interrupt_init; /* start value for current countdown */
#endif
/* Builtin-objects; may or may not be shared with other threads,
* threads existing in different "compartments" will have different
* built-ins. Must be stored on a per-thread basis because there
* is no intermediate structure for a thread group / compartment.
* This takes quite a lot of space, currently 43x4 = 172 bytes on
* 32-bit platforms.
*
* In some cases the builtins array could be ROM based, but it's
* sometimes edited (e.g. for sandboxing) so it's better to keep
* this array in RAM.
*/
duk_hobject *builtins[DUK_NUM_BUILTINS];
/* Convenience copies from heap/vm for faster access. */
#if defined(DUK_USE_ROM_STRINGS)
/* No field needed when strings are in ROM. */
#else
#if defined(DUK_USE_HEAPPTR16)
duk_uint16_t *strs16;
#else
duk_hstring **strs;
#endif
#endif
};
/*
* Prototypes
*/
DUK_INTERNAL_DECL void duk_hthread_copy_builtin_objects(duk_hthread *thr_from, duk_hthread *thr_to);
DUK_INTERNAL_DECL void duk_hthread_create_builtin_objects(duk_hthread *thr);
DUK_INTERNAL_DECL duk_bool_t duk_hthread_init_stacks(duk_heap *heap, duk_hthread *thr);
DUK_INTERNAL_DECL void duk_hthread_terminate(duk_hthread *thr);
DUK_INTERNAL_DECL duk_activation *duk_hthread_activation_alloc(duk_hthread *thr);
DUK_INTERNAL_DECL void duk_hthread_activation_free(duk_hthread *thr, duk_activation *act);
DUK_INTERNAL_DECL void duk_hthread_activation_unwind_norz(duk_hthread *thr);
DUK_INTERNAL_DECL void duk_hthread_activation_unwind_reuse_norz(duk_hthread *thr);
DUK_INTERNAL_DECL duk_activation *duk_hthread_get_activation_for_level(duk_hthread *thr, duk_int_t level);
DUK_INTERNAL_DECL duk_catcher *duk_hthread_catcher_alloc(duk_hthread *thr);
DUK_INTERNAL_DECL void duk_hthread_catcher_free(duk_hthread *thr, duk_catcher *cat);
DUK_INTERNAL_DECL void duk_hthread_catcher_unwind_norz(duk_hthread *thr, duk_activation *act);
DUK_INTERNAL_DECL void duk_hthread_catcher_unwind_nolexenv_norz(duk_hthread *thr, duk_activation *act);
#if defined(DUK_USE_FINALIZER_TORTURE)
DUK_INTERNAL_DECL void duk_hthread_valstack_torture_realloc(duk_hthread *thr);
#endif
DUK_INTERNAL_DECL void *duk_hthread_get_valstack_ptr(duk_heap *heap, void *ud); /* indirect allocs */
#if defined(DUK_USE_DEBUGGER_SUPPORT)
DUK_INTERNAL_DECL duk_uint_fast32_t duk_hthread_get_act_curr_pc(duk_hthread *thr, duk_activation *act);
#endif
DUK_INTERNAL_DECL duk_uint_fast32_t duk_hthread_get_act_prev_pc(duk_hthread *thr, duk_activation *act);
DUK_INTERNAL_DECL void duk_hthread_sync_currpc(duk_hthread *thr);
DUK_INTERNAL_DECL void duk_hthread_sync_and_null_currpc(duk_hthread *thr);
#endif /* DUK_HTHREAD_H_INCLUDED */
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