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-rwxr-xr-xell.c193
1 files changed, 86 insertions, 107 deletions
diff --git a/ell.c b/ell.c
index d14c732..e277d3f 100755
--- a/ell.c
+++ b/ell.c
@@ -160,8 +160,8 @@ new_clone (const struct item *item) {
return NULL;
memcpy (clone, item, size);
- if (item->type == ITEM_LIST) {
- if (clone->head && !(clone->head = new_clone_list (clone->head))) {
+ if (item->type == ITEM_LIST && clone->head) {
+ if (!(clone->head = new_clone_list (clone->head))) {
free (clone);
return NULL;
}
@@ -475,8 +475,7 @@ parser_peek (struct parser *self, jmp_buf out) {
!(self->error = lexer_errorf (&self->lexer, "%s", e));
longjmp (out, 1);
}
- if (self->token == T_STRING
- && (self->memory_failure = self->lexer.string.memory_failure))
+ if (self->token == T_STRING && self->lexer.string.memory_failure)
longjmp (out, 1);
self->replace_token = false;
}
@@ -615,11 +614,9 @@ parser_run (struct parser *self, const char **e) {
struct item *volatile result = NULL, *volatile *tail = &result;
if (setjmp (err)) {
item_free_list (result);
- if (e) {
- *e = self->error;
- if (self->memory_failure)
- *e = "memory allocation failure";
- }
+ *e = self->error;
+ if (self->memory_failure || self->lexer.string.memory_failure)
+ *e = "memory allocation failure";
return NULL;
}
@@ -667,9 +664,6 @@ native_register (const char *name, handler_fn handler) {
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-// TODO: fill in "error_is_fatal"
-// TODO: probably add new_*() methods that set "memory_failure"
-
struct context {
struct item *variables; ///< List of variables
@@ -691,6 +685,11 @@ context_free (struct context *ctx) {
free (ctx->error);
}
+static bool
+check (struct context *ctx, struct item *item) {
+ return !(ctx->memory_failure |= !item);
+}
+
static struct item *
get (struct context *ctx, const char *name) {
for (struct item *iter = ctx->variables; iter; iter = iter->next)
@@ -701,49 +700,36 @@ get (struct context *ctx, const char *name) {
static bool
set (struct context *ctx, const char *name, struct item *value) {
- struct item *iter, *key = NULL, *pair = NULL;
+ struct item *iter, *key, *pair;
for (iter = ctx->variables; iter; iter = iter->next)
if (!strcmp (iter->head->value, name))
break;
if (iter) {
item_free (iter->head->next);
- if (!(iter->head->next = new_clone (value))) {
- ctx->memory_failure = true;
- return false;
- }
- return true;
+ return check (ctx, (iter->head->next = new_clone (value)));
}
- if ((key = new_string (name, strlen (name)))
- && (pair = new_list (NULL))) {
- if (!((pair->head = key)->next = new_clone (value))) {
- item_free (pair);
- ctx->memory_failure = true;
- return false;
- }
- pair->next = ctx->variables;
- ctx->variables = pair;
- return true;
- } else {
- item_free_list (key);
- item_free_list (pair);
- ctx->memory_failure = true;
+ if (!check (ctx, (key = new_string (name, strlen (name))))
+ || !check (ctx, (pair = new_list (key))))
+ return false;
+ if (!check (ctx, (key->next = new_clone (value)))) {
+ item_free (pair);
return false;
}
+ pair->next = ctx->variables;
+ ctx->variables = pair;
+ return true;
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
static bool
set_error (struct context *ctx, const char *format, ...) {
- free (ctx->error);
-
va_list ap;
va_start (ap, format);
- ctx->error = vformat (format, ap);
- va_end (ap);
-
- if (!ctx->error)
+ free (ctx->error);
+ if (!(ctx->error = vformat (format, ap)))
ctx->memory_failure = true;
+ va_end (ap);
return false;
}
@@ -760,7 +746,7 @@ rename_arguments (struct context *ctx, struct item *names) {
return true;
if (names->type != ITEM_STRING)
- continue;
+ return set_error (ctx, "argument names must be strings");
if (!set (ctx, names->value, value))
return false;
}
@@ -771,44 +757,33 @@ static bool execute_statement (struct context *, struct item *, struct item **);
static bool execute (struct context *ctx, struct item *body, struct item **);
static bool
-execute_args_list (struct context *ctx, struct item *args, struct item **res) {
- for (struct item *arg = args; arg; arg = arg->next) {
+execute_args (struct context *ctx, struct item *args, struct item **res) {
+ for (; args; args = args->next) {
struct item *evaluated = NULL;
- if (!execute_statement (ctx, arg, &evaluated))
+ if (!execute_statement (ctx, args, &evaluated))
return false;
if (evaluated) {
item_free_list (evaluated->next);
evaluated->next = NULL;
- *res = evaluated;
- res = &evaluated->next;
+ res = &(*res = evaluated)->next;
}
}
return true;
}
-static bool
-execute_native (struct context *ctx,
- struct native_fn *fn, struct item *next, struct item **res) {
- struct item *args = NULL;
- bool ok = execute_args_list (ctx, next, &args)
- && fn->handler (ctx, args, res);
- item_free_list (args);
- return ok;
-}
-
// TODO: we should probably maintain arguments in a separate list,
// either that or at least remember the count so that we can reset them
static bool
-execute_args (struct context *ctx, struct item *next) {
+execute_args_and_set (struct context *ctx, struct item *following) {
struct item *args = NULL;
- if (!execute_args_list (ctx, next, &args)) {
+ if (!execute_args (ctx, following, &args)) {
item_free_list (args);
return false;
}
- char buf[64];
size_t i = 0;
for (struct item *arg = args; arg; arg = arg->next) {
+ char buf[64];
(void) snprintf (buf, sizeof buf, "%zu", i++);
if (!set (ctx, buf, arg))
return false;
@@ -818,14 +793,20 @@ execute_args (struct context *ctx, struct item *next) {
}
static bool
+execute_native (struct context *ctx,
+ struct native_fn *fn, struct item *next, struct item **res) {
+ struct item *args = NULL;
+ bool ok = execute_args (ctx, next, &args)
+ && fn->handler (ctx, args, res);
+ item_free_list (args);
+ return ok;
+}
+
+static bool
execute_statement
(struct context *ctx, struct item *statement, struct item **result) {
- if (statement->type == ITEM_STRING) {
- if ((*result = new_clone (statement)))
- return true;
- ctx->memory_failure = true;
- return false;
- }
+ if (statement->type == ITEM_STRING)
+ return check (ctx, (*result = new_clone (statement)));
// XXX: should this ever happen and what are the consequences?
// Shouldn't we rather clone the empty list?
@@ -838,12 +819,10 @@ execute_statement
if (body->type == ITEM_STRING) {
name = body->value;
// TODO: these could be just regular handlers, only top priority
- if (!strcmp (name, "quote")) {
- if (!following || (*result = new_clone_list (following)))
- return true;
- ctx->memory_failure = true;
- return false;
- }
+ // TODO: these should also get a stack trace the normal way
+ if (!strcmp (name, "quote"))
+ return !following
+ || check (ctx, (*result = new_clone_list (following)));
if (!strcmp (name, "arg"))
return rename_arguments (ctx, following);
body = get (ctx, name);
@@ -857,23 +836,21 @@ execute_statement
return true;
} else if (body->type == ITEM_STRING) {
// Recursion could be pretty fatal, let's not do that
- if ((*result = new_clone (body)))
+ if (check (ctx, (*result = new_clone (body))))
return true;
- ctx->memory_failure = true;
} else {
- if (execute_args (ctx, following)
+ if (execute_args_and_set (ctx, following)
&& execute (ctx, body->head, result))
return true;
}
- // In this case, `error' is NULL
- if (ctx->memory_failure)
- return false;
-
- // This creates some form of a stack trace
- char *tmp = ctx->error;
- set_error (ctx, "%s -> %s", name, tmp);
- free (tmp);
+ // In that case, `error' is NULL and there's nothing else to do anyway
+ if (!ctx->memory_failure) {
+ // This creates some form of a stack trace
+ char *tmp = ctx->error;
+ set_error (ctx, "%s -> %s", name, tmp);
+ free (tmp);
+ }
return false;
}
@@ -925,56 +902,59 @@ init_runtime_library_scripts (struct context *ctx) {
defn (fn_set) {
struct item *name = args;
if (!name || name->type != ITEM_STRING)
- return (void *) set_error (ctx, "first argument must be string");
+ return set_error (ctx, "first argument must be string");
struct item *value;
if ((value = name->next))
return set (ctx, name->value, value);
// FIXME: how do we represent a nil value here?
- *result = new_clone (get (ctx, name->value));
- return true;
+ return check (ctx, (*result = new_clone (get (ctx, name->value))));
+}
+
+defn (fn_list) {
+ struct item *values = NULL;
+ if (args && !check (ctx, (values = new_clone_list (args))))
+ return false;
+ return check (ctx, (*result = new_list (values)));
}
defn (fn_print) {
(void) result;
-
- // TODO: error on list
- struct buffer buf = BUFFER_INITIALIZER;
- for (; args; args = args->next)
- buffer_append (&buf, args->value, args->len);
- buffer_append_c (&buf, '\0');
- if (buf.memory_failure) {
- ctx->memory_failure = true;
- return false;
+ for (; args; args = args->next) {
+ if (args->type != ITEM_STRING)
+ // TODO: print lists as their parsable representation
+ return set_error (ctx, "cannot print lists");
+ if (fwrite (args->value, 1, args->len, stdout) != args->len)
+ return set_error (ctx, "write failed: %s", strerror (errno));
}
-
- printf ("%s", buf.s);
- free (buf.s);
return true;
}
defn (fn_concatenate) {
- // TODO: error on list
struct buffer buf = BUFFER_INITIALIZER;
- for (; args; args = args->next)
+ for (; args; args = args->next) {
+ if (args->type != ITEM_STRING) {
+ free (buf.s);
+ return set_error (ctx, "cannot concatenate lists");
+ }
buffer_append (&buf, args->value, args->len);
- buffer_append_c (&buf, '\0');
- if (buf.memory_failure) {
- ctx->memory_failure = true;
- return false;
}
- *result = new_string (buf.s, buf.len);
+ buffer_append_c (&buf, '\0');
+
+ bool ok = !(ctx->memory_failure = buf.memory_failure)
+ && check (ctx, (*result = new_string (buf.s, buf.len)));
free (buf.s);
- return true;
+ return ok;
}
static bool
init_runtime_library (void)
{
- return native_register ("..", fn_concatenate)
- && native_register ("set", fn_set)
- && native_register ("print", fn_print);
+ return native_register ("set", fn_set)
+ && native_register ("list", fn_list)
+ && native_register ("print", fn_print)
+ && native_register ("..", fn_concatenate);
}
static void
@@ -1008,7 +988,6 @@ main (int argc, char *argv[]) {
const char *e = NULL;
struct item *program = parser_run (&parser, &e);
free (buf.s);
-
if (e) {
printf ("%s: %s\n", "parse error", e);
return 1;