diff options
| -rw-r--r-- | src/emacs-module.c | 373 | ||||
| -rw-r--r-- | test/data/emacs-module/mod-test.c | 6 | ||||
| -rw-r--r-- | test/src/emacs-module-tests.el | 3 |
3 files changed, 180 insertions, 202 deletions
diff --git a/src/emacs-module.c b/src/emacs-module.c index 4e2411cb295..df9a491a864 100644 --- a/src/emacs-module.c +++ b/src/emacs-module.c @@ -25,6 +25,7 @@ along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>. */ #include <stddef.h> #include <stdint.h> #include <stdio.h> +#include <stdlib.h> #include "lisp.h" #include "dynlib.h" @@ -65,18 +66,6 @@ along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>. */ #include "w32term.h" #endif -/* True if Lisp_Object and emacs_value have the same representation. - This is typically true unless WIDE_EMACS_INT. In practice, having - the same sizes and alignments and maximums should be a good enough - proxy for equality of representation. */ -enum - { - plain_values - = (sizeof (Lisp_Object) == sizeof (emacs_value) - && alignof (Lisp_Object) == alignof (emacs_value) - && INTPTR_MAX == EMACS_INT_MAX) - }; - /* Function prototype for the module init function. */ typedef int (*emacs_init_function) (struct emacs_runtime *); @@ -87,6 +76,43 @@ typedef int (*emacs_init_function) (struct emacs_runtime *); typedef void (*emacs_finalizer_function) (void *); +/* Memory management. */ + +/* An `emacs_value' is just a pointer to a structure holding an + internal Lisp object. */ +struct emacs_value_tag { Lisp_Object v; }; + +/* Local value objects use a simple fixed-sized block allocation + scheme without explicit deallocation. All local values are + deallocated when the lifetime of their environment ends. Keep + track of a current frame from which new values are allocated, + appending further dynamically-allocated frames if necessary. */ + +enum { value_frame_size = 512 }; + +/* A block from which `emacs_value' object can be allocated. */ +struct emacs_value_frame +{ + /* Storage for values. */ + struct emacs_value_tag objects[value_frame_size]; + + /* Index of the next free value in `objects'. */ + int offset; + + /* Pointer to next frame, if any. */ + struct emacs_value_frame *next; +}; + +/* A structure that holds an initial frame (so that the first local + values require no dynamic allocation) and keeps track of the + current frame. */ +static struct emacs_value_storage +{ + struct emacs_value_frame initial; + struct emacs_value_frame *current; +} global_storage; + + /* Private runtime and environment members. */ /* The private part of an environment stores the current non local exit state @@ -99,12 +125,9 @@ struct emacs_env_private /* Dedicated storage for non-local exit symbol and data so that storage is always available for them, even in an out-of-memory situation. */ - Lisp_Object non_local_exit_symbol, non_local_exit_data; + struct emacs_value_tag non_local_exit_symbol, non_local_exit_data; - /* List of values allocated from this environment. The code uses - this only if the user gave the -module-assertions command-line - option. */ - Lisp_Object values; + struct emacs_value_storage storage; }; /* The private parts of an `emacs_runtime' object contain the initial @@ -118,6 +141,7 @@ struct emacs_runtime_private /* Forward declarations. */ static Lisp_Object value_to_lisp (emacs_value); +static emacs_value allocate_emacs_value (emacs_env *, struct emacs_value_storage *, Lisp_Object); static emacs_value lisp_to_value (emacs_env *, Lisp_Object); static enum emacs_funcall_exit module_non_local_exit_check (emacs_env *); static void module_assert_thread (void); @@ -139,16 +163,7 @@ static void module_non_local_exit_throw_1 (emacs_env *, static void module_out_of_memory (emacs_env *); static void module_reset_handlerlist (struct handler **); -/* We used to return NULL when emacs_value was a different type from - Lisp_Object, but nowadays we just use Qnil instead. Although they - happen to be the same thing in the current implementation, module - code should not assume this. */ -verify (NIL_IS_ZERO); -static emacs_value const module_nil = 0; - static bool module_assertions = false; -static emacs_env *global_env; -static struct emacs_env_private global_env_private; /* Convenience macros for non-local exit handling. */ @@ -293,7 +308,7 @@ module_get_environment (struct emacs_runtime *ert) static emacs_value module_make_global_ref (emacs_env *env, emacs_value ref) { - MODULE_FUNCTION_BEGIN (module_nil); + MODULE_FUNCTION_BEGIN (NULL); struct Lisp_Hash_Table *h = XHASH_TABLE (Vmodule_refs_hash); Lisp_Object new_obj = value_to_lisp (ref); EMACS_UINT hashcode; @@ -313,7 +328,7 @@ module_make_global_ref (emacs_env *env, emacs_value ref) hash_put (h, new_obj, make_fixed_natnum (1), hashcode); } - return lisp_to_value (module_assertions ? global_env : env, new_obj); + return allocate_emacs_value (env, &global_storage, new_obj); } static void @@ -341,23 +356,16 @@ module_free_global_ref (emacs_env *env, emacs_value ref) if (module_assertions) { - Lisp_Object globals = global_env_private.values; - Lisp_Object prev = Qnil; ptrdiff_t count = 0; - for (Lisp_Object tail = globals; CONSP (tail); - tail = XCDR (tail)) + for (struct emacs_value_frame *frame = &global_storage.initial; + frame != NULL; frame = frame->next) { - emacs_value global = xmint_pointer (XCAR (tail)); - if (global == ref) + for (int i = 0; i < frame->offset; ++i) { - if (NILP (prev)) - global_env_private.values = XCDR (globals); - else - XSETCDR (prev, XCDR (tail)); - return; + if (&frame->objects[i] == ref) + return; + ++count; } - ++count; - prev = tail; } module_abort ("Global value was not found in list of %"pD"d globals", count); @@ -388,9 +396,8 @@ module_non_local_exit_get (emacs_env *env, emacs_value *sym, emacs_value *data) struct emacs_env_private *p = env->private_members; if (p->pending_non_local_exit != emacs_funcall_exit_return) { - /* FIXME: lisp_to_value can exit non-locally. */ - *sym = lisp_to_value (env, p->non_local_exit_symbol); - *data = lisp_to_value (env, p->non_local_exit_data); + *sym = &p->non_local_exit_symbol; + *data = &p->non_local_exit_data; } return p->pending_non_local_exit; } @@ -434,7 +441,7 @@ module_make_function (emacs_env *env, ptrdiff_t min_arity, ptrdiff_t max_arity, emacs_subr subr, const char *documentation, void *data) { - MODULE_FUNCTION_BEGIN (module_nil); + MODULE_FUNCTION_BEGIN (NULL); if (! (0 <= min_arity && (max_arity < 0 @@ -467,7 +474,7 @@ static emacs_value module_funcall (emacs_env *env, emacs_value fun, ptrdiff_t nargs, emacs_value args[]) { - MODULE_FUNCTION_BEGIN (module_nil); + MODULE_FUNCTION_BEGIN (NULL); /* Make a new Lisp_Object array starting with the function as the first arg, because that's what Ffuncall takes. */ @@ -488,14 +495,14 @@ module_funcall (emacs_env *env, emacs_value fun, ptrdiff_t nargs, static emacs_value module_intern (emacs_env *env, const char *name) { - MODULE_FUNCTION_BEGIN (module_nil); + MODULE_FUNCTION_BEGIN (NULL); return lisp_to_value (env, intern (name)); } static emacs_value module_type_of (emacs_env *env, emacs_value value) { - MODULE_FUNCTION_BEGIN (module_nil); + MODULE_FUNCTION_BEGIN (NULL); return lisp_to_value (env, Ftype_of (value_to_lisp (value))); } @@ -528,7 +535,7 @@ module_extract_integer (emacs_env *env, emacs_value n) static emacs_value module_make_integer (emacs_env *env, intmax_t n) { - MODULE_FUNCTION_BEGIN (module_nil); + MODULE_FUNCTION_BEGIN (NULL); return lisp_to_value (env, make_int (n)); } @@ -544,7 +551,7 @@ module_extract_float (emacs_env *env, emacs_value f) static emacs_value module_make_float (emacs_env *env, double d) { - MODULE_FUNCTION_BEGIN (module_nil); + MODULE_FUNCTION_BEGIN (NULL); return lisp_to_value (env, make_float (d)); } @@ -581,7 +588,7 @@ module_copy_string_contents (emacs_env *env, emacs_value value, char *buffer, static emacs_value module_make_string (emacs_env *env, const char *str, ptrdiff_t length) { - MODULE_FUNCTION_BEGIN (module_nil); + MODULE_FUNCTION_BEGIN (NULL); if (! (0 <= length && length <= STRING_BYTES_BOUND)) overflow_error (); /* FIXME: AUTO_STRING_WITH_LEN requires STR to be null-terminated, @@ -594,7 +601,7 @@ module_make_string (emacs_env *env, const char *str, ptrdiff_t length) static emacs_value module_make_user_ptr (emacs_env *env, emacs_finalizer_function fin, void *ptr) { - MODULE_FUNCTION_BEGIN (module_nil); + MODULE_FUNCTION_BEGIN (NULL); return lisp_to_value (env, make_user_ptr (fin, ptr)); } @@ -656,7 +663,7 @@ module_vec_set (emacs_env *env, emacs_value vec, ptrdiff_t i, emacs_value val) static emacs_value module_vec_get (emacs_env *env, emacs_value vec, ptrdiff_t i) { - MODULE_FUNCTION_BEGIN (module_nil); + MODULE_FUNCTION_BEGIN (NULL); Lisp_Object lvec = value_to_lisp (vec); check_vec_index (lvec, i); return lisp_to_value (env, AREF (lvec, i)); @@ -699,9 +706,11 @@ module_signal_or_throw (struct emacs_env_private *env) case emacs_funcall_exit_return: return; case emacs_funcall_exit_signal: - xsignal (env->non_local_exit_symbol, env->non_local_exit_data); + xsignal (value_to_lisp (&env->non_local_exit_symbol), + value_to_lisp (&env->non_local_exit_data)); case emacs_funcall_exit_throw: - Fthrow (env->non_local_exit_symbol, env->non_local_exit_data); + Fthrow (value_to_lisp (&env->non_local_exit_symbol), + value_to_lisp (&env->non_local_exit_data)); default: eassume (false); } @@ -777,17 +786,12 @@ funcall_module (Lisp_Object function, ptrdiff_t nargs, Lisp_Object *arglist) record_unwind_protect_ptr (finalize_environment_unwind, env); USE_SAFE_ALLOCA; - ATTRIBUTE_MAY_ALIAS emacs_value *args; - if (plain_values && ! module_assertions) - /* FIXME: The cast below is incorrect because the argument array - is not declared as const, so module functions can modify it. - Either declare it as const, or remove this branch. */ - args = (emacs_value *) arglist; - else + emacs_value *args = nargs > 0 ? SAFE_ALLOCA (nargs * sizeof *args) : NULL; + for (ptrdiff_t i = 0; i < nargs; ++i) { - args = SAFE_ALLOCA (nargs * sizeof *args); - for (ptrdiff_t i = 0; i < nargs; i++) - args[i] = lisp_to_value (env, arglist[i]); + args[i] = lisp_to_value (env, arglist[i]); + if (! args[i]) + memory_full (sizeof *args[i]); } emacs_value ret = func->subr (env, nargs, args, func->data); @@ -867,8 +871,8 @@ module_non_local_exit_signal_1 (emacs_env *env, Lisp_Object sym, if (p->pending_non_local_exit == emacs_funcall_exit_return) { p->pending_non_local_exit = emacs_funcall_exit_signal; - p->non_local_exit_symbol = sym; - p->non_local_exit_data = data; + p->non_local_exit_symbol.v = sym; + p->non_local_exit_data.v = data; } } @@ -880,8 +884,8 @@ module_non_local_exit_throw_1 (emacs_env *env, Lisp_Object tag, if (p->pending_non_local_exit == emacs_funcall_exit_return) { p->pending_non_local_exit = emacs_funcall_exit_throw; - p->non_local_exit_symbol = tag; - p->non_local_exit_data = value; + p->non_local_exit_symbol.v = tag; + p->non_local_exit_data.v = value; } } @@ -898,54 +902,8 @@ module_out_of_memory (emacs_env *env) /* Value conversion. */ -/* We represent Lisp objects differently depending on whether the user - gave -module-assertions. If assertions are disabled, emacs_value - objects are Lisp_Objects cast to emacs_value. If assertions are - enabled, emacs_value objects are pointers to Lisp_Object objects - allocated from the free store; they are never freed, which ensures - that their addresses are unique and can be used for liveness - checking. */ - -/* Unique Lisp_Object used to mark those emacs_values which are really - just containers holding a Lisp_Object that does not fit as an emacs_value, - either because it is an integer out of range, or is not properly aligned. - Used only if !plain_values. */ -static Lisp_Object ltv_mark; - -/* Convert V to the corresponding internal object O, such that - V == lisp_to_value_bits (O). Never fails. */ -static Lisp_Object -value_to_lisp_bits (emacs_value v) -{ - if (plain_values || USE_LSB_TAG) - return XPL (v); - - /* With wide EMACS_INT and when tag bits are the most significant, - reassembling integers differs from reassembling pointers in two - ways. First, save and restore the least-significant bits of the - integer, not the most-significant bits. Second, sign-extend the - integer when restoring, but zero-extend pointers because that - makes TAG_PTR faster. */ - - intptr_t i = (intptr_t) v; - EMACS_UINT tag = i & ((1 << GCTYPEBITS) - 1); - EMACS_UINT untagged = i - tag; - switch (tag) - { - case_Lisp_Int: - { - bool negative = tag & 1; - EMACS_UINT sign_extension - = negative ? VALMASK & ~(INTPTR_MAX >> INTTYPEBITS): 0; - uintptr_t u = i; - intptr_t all_but_sign = u >> GCTYPEBITS; - untagged = sign_extension + all_but_sign; - break; - } - } - - return XIL ((tag << VALBITS) + untagged); -} +/* Convert an `emacs_value' to the corresponding internal object. + Never fails. */ /* If V was computed from lisp_to_value (O), then return O. Exits non-locally only if the stack overflows. */ @@ -956,91 +914,134 @@ value_to_lisp (emacs_value v) { /* Check the liveness of the value by iterating over all live environments. */ - void *vptr = v; - ATTRIBUTE_MAY_ALIAS Lisp_Object *optr = vptr; ptrdiff_t num_environments = 0; ptrdiff_t num_values = 0; for (Lisp_Object environments = Vmodule_environments; CONSP (environments); environments = XCDR (environments)) { emacs_env *env = xmint_pointer (XCAR (environments)); - for (Lisp_Object values = env->private_members->values; - CONSP (values); values = XCDR (values)) + struct emacs_env_private *priv = env->private_members; + /* The value might be one of the nonlocal exit values. Note + that we don't check whether a nonlocal exit is currently + pending, because the module might have cleared the flag + in the meantime. */ + if (&priv->non_local_exit_symbol == v + || &priv->non_local_exit_data == v) + goto ok; + for (struct emacs_value_frame *frame = &priv->storage.initial; + frame != NULL; frame = frame->next) { - Lisp_Object *p = xmint_pointer (XCAR (values)); - if (p == optr) - return *p; - ++num_values; + for (int i = 0; i < frame->offset; ++i) + { + if (&frame->objects[i] == v) + goto ok; + ++num_values; + } } ++num_environments; } + /* Also check global values. */ + for (struct emacs_value_frame *frame = &global_storage.initial; + frame != NULL; frame = frame->next) + { + for (int i = 0; i < frame->offset; ++i) + { + if (&frame->objects[i] == v) + goto ok; + ++num_values; + } + } module_abort (("Emacs value not found in %"pD"d values " "of %"pD"d environments"), num_values, num_environments); } - Lisp_Object o = value_to_lisp_bits (v); - if (! plain_values && CONSP (o) && EQ (XCDR (o), ltv_mark)) - o = XCAR (o); - return o; + ok: return v->v; } -/* Attempt to convert O to an emacs_value. Do not do any checking - or allocate any storage; the caller should prevent or detect - any resulting bit pattern that is not a valid emacs_value. */ +/* Convert an internal object to an `emacs_value'. Allocate storage + from the environment; return NULL if allocation fails. */ static emacs_value -lisp_to_value_bits (Lisp_Object o) +lisp_to_value (emacs_env *env, Lisp_Object o) { - if (plain_values || USE_LSB_TAG) - return XLP (o); + struct emacs_env_private *p = env->private_members; + if (p->pending_non_local_exit != emacs_funcall_exit_return) + return NULL; + return allocate_emacs_value (env, &p->storage, o); +} - /* Compress O into the space of a pointer, possibly losing information. */ - EMACS_UINT u = XLI (o); - if (FIXNUMP (o)) - { - uintptr_t i = (u << VALBITS) + XTYPE (o); - return (emacs_value) i; - } - else +/* Must be called for each frame before it can be used for allocation. */ +static void +initialize_frame (struct emacs_value_frame *frame) +{ + frame->offset = 0; + frame->next = NULL; +} + +/* Must be called for any storage object before it can be used for + allocation. */ +static void +initialize_storage (struct emacs_value_storage *storage) +{ + initialize_frame (&storage->initial); + storage->current = &storage->initial; +} + +/* Must be called for any initialized storage object before its + lifetime ends. Free all dynamically-allocated frames. */ +static void +finalize_storage (struct emacs_value_storage *storage) +{ + struct emacs_value_frame *next = storage->initial.next; + while (next != NULL) { - char *p = XLP (o); - void *v = p - (u & ~VALMASK) + XTYPE (o); - return v; + struct emacs_value_frame *current = next; + next = current->next; + free (current); } } -/* Convert O to an emacs_value. Allocate storage if needed; this can - signal if memory is exhausted. Must be an injective function. */ +/* Allocate a new value from STORAGE and stores OBJ in it. Return + NULL if allocation fails and use ENV for non local exit reporting. */ static emacs_value -lisp_to_value (emacs_env *env, Lisp_Object o) +allocate_emacs_value (emacs_env *env, struct emacs_value_storage *storage, + Lisp_Object obj) { - if (module_assertions) + eassert (storage->current); + eassert (storage->current->offset < value_frame_size); + eassert (! storage->current->next); + if (storage->current->offset == value_frame_size - 1) { - /* Add the new value to the list of values allocated from this - environment. The value is actually a pointer to the - Lisp_Object cast to emacs_value. We make a copy of the - object on the free store to guarantee unique addresses. */ - ATTRIBUTE_MAY_ALIAS Lisp_Object *optr = xmalloc (sizeof o); - *optr = o; - void *vptr = optr; - ATTRIBUTE_MAY_ALIAS emacs_value ret = vptr; - struct emacs_env_private *priv = env->private_members; - priv->values = Fcons (make_mint_ptr (ret), priv->values); - return ret; + storage->current->next = malloc (sizeof *storage->current->next); + if (! storage->current->next) + { + module_out_of_memory (env); + return NULL; + } + initialize_frame (storage->current->next); + storage->current = storage->current->next; } + emacs_value value = storage->current->objects + storage->current->offset; + value->v = obj; + ++storage->current->offset; + return value; +} - emacs_value v = lisp_to_value_bits (o); - - if (! EQ (o, value_to_lisp_bits (v))) +/* Mark all objects allocated from local environments so that they + don't get garbage-collected. */ +void +mark_modules (void) +{ + for (Lisp_Object tem = Vmodule_environments; CONSP (tem); tem = XCDR (tem)) { - /* Package the incompressible object pointer inside a pair - that is compressible. */ - Lisp_Object pair = Fcons (o, ltv_mark); - v = (emacs_value) ((intptr_t) XCONS (pair) + Lisp_Cons); + emacs_env *env = xmint_pointer (XCAR (tem)); + struct emacs_env_private *priv = env->private_members; + for (struct emacs_value_frame *frame = &priv->storage.initial; + frame != NULL; + frame = frame->next) + for (int i = 0; i < frame->offset; ++i) + mark_object (frame->objects[i].v); } - - eassert (EQ (o, value_to_lisp (v))); - return v; } @@ -1059,7 +1060,7 @@ initialize_environment (emacs_env *env, struct emacs_env_private *priv) env = xmalloc (sizeof *env); priv->pending_non_local_exit = emacs_funcall_exit_return; - priv->values = priv->non_local_exit_symbol = priv->non_local_exit_data = Qnil; + initialize_storage (&priv->storage); env->size = sizeof *env; env->private_members = priv; env->make_global_ref = module_make_global_ref; @@ -1100,11 +1101,9 @@ initialize_environment (emacs_env *env, struct emacs_env_private *priv) static void finalize_environment (emacs_env *env) { + finalize_storage (&env->private_members->storage); eassert (xmint_pointer (XCAR (Vmodule_environments)) == env); Vmodule_environments = XCDR (Vmodule_environments); - if (module_assertions) - /* There is always at least the global environment. */ - eassert (CONSP (Vmodule_environments)); } static void @@ -1122,20 +1121,6 @@ finalize_runtime_unwind (void *raw_ert) finalize_environment (ert->private_members->env); } -void -mark_modules (void) -{ - for (Lisp_Object tail = Vmodule_environments; CONSP (tail); - tail = XCDR (tail)) - { - emacs_env *env = xmint_pointer (XCAR (tail)); - struct emacs_env_private *priv = env->private_members; - mark_object (priv->non_local_exit_symbol); - mark_object (priv->non_local_exit_data); - mark_object (priv->values); - } -} - /* Non-local exit handling. */ @@ -1175,8 +1160,7 @@ init_module_assertions (bool enable) /* If enabling module assertions, use a hidden environment for storing the globals. This environment is never freed. */ module_assertions = enable; - if (enable) - global_env = initialize_environment (NULL, &global_env_private); + initialize_storage (&global_storage); } static _Noreturn void @@ -1199,13 +1183,6 @@ module_abort (const char *format, ...) void syms_of_module (void) { - if (!plain_values) - { - ltv_mark = Fcons (Qnil, Qnil); - staticpro (<v_mark); - } - eassert (NILP (value_to_lisp (module_nil))); - DEFSYM (Qmodule_refs_hash, "module-refs-hash"); DEFVAR_LISP ("module-refs-hash", Vmodule_refs_hash, doc: /* Module global reference table. */); diff --git a/test/data/emacs-module/mod-test.c b/test/data/emacs-module/mod-test.c index 47ea159d0e7..a39e41afee6 100644 --- a/test/data/emacs-module/mod-test.c +++ b/test/data/emacs-module/mod-test.c @@ -94,7 +94,7 @@ Fmod_test_signal (emacs_env *env, ptrdiff_t nargs, emacs_value args[], assert (env->non_local_exit_check (env) == emacs_funcall_exit_return); env->non_local_exit_signal (env, env->intern (env, "error"), env->make_integer (env, 56)); - return env->intern (env, "nil"); + return NULL; } @@ -106,7 +106,7 @@ Fmod_test_throw (emacs_env *env, ptrdiff_t nargs, emacs_value args[], assert (env->non_local_exit_check (env) == emacs_funcall_exit_return); env->non_local_exit_throw (env, env->intern (env, "tag"), env->make_integer (env, 65)); - return env->intern (env, "nil"); + return NULL; } @@ -304,7 +304,7 @@ Fmod_test_invalid_finalizer (emacs_env *env, ptrdiff_t nargs, emacs_value *args, { current_env = env; env->make_user_ptr (env, invalid_finalizer, NULL); - return env->funcall (env, env->intern (env, "garbage-collect"), 0, NULL); + return env->intern (env, "nil"); } static void diff --git a/test/src/emacs-module-tests.el b/test/src/emacs-module-tests.el index e30980b5993..35aaaa64b65 100644 --- a/test/src/emacs-module-tests.el +++ b/test/src/emacs-module-tests.el @@ -265,7 +265,8 @@ during garbage collection." (skip-unless (file-executable-p mod-test-emacs)) (module--test-assertion (rx "Module function called during garbage collection\n") - (mod-test-invalid-finalizer))) + (mod-test-invalid-finalizer) + (garbage-collect))) (ert-deftest module/describe-function-1 () "Check that Bug#30163 is fixed." |