From e290683f0c88d88b90aab587bee87d548fdb594f Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?P=C5=99emysl=20Janouch?= Date: Wed, 17 May 2017 21:29:07 +0200 Subject: [PATCH] Get rid of the "script" parser Since it is largely incompatible with what we're doing. --- ell.c | 297 ++++++++-------------------------------------------------- 1 file changed, 38 insertions(+), 259 deletions(-) diff --git a/ell.c b/ell.c index 9d786e4..f26a2aa 100755 --- a/ell.c +++ b/ell.c @@ -44,7 +44,7 @@ static char *format (const char *format, ...) ATTRIBUTE_PRINTF (1, 2); static char * -strdup_vprintf (const char *format, va_list ap) { +vformat (const char *format, va_list ap) { va_list aq; va_copy (aq, ap); int size = vsnprintf (NULL, 0, format, aq); @@ -64,7 +64,7 @@ static char * format (const char *format, ...) { va_list ap; va_start (ap, format); - char *result = strdup_vprintf (format, ap); + char *result = vformat (format, ap); va_end (ap); return result; } @@ -135,7 +135,7 @@ static struct item *new_clone_list (const struct item *); static void item_free (struct item *item) { if (item->type == ITEM_LIST) - item_free_list (get_list (item)); + item_free_list (item->head); free (item); } @@ -257,7 +257,7 @@ struct lexer { unsigned column; ///< Current column int64_t integer; ///< Parsed boolean or integer value - struct str string; ///< Parsed string value + struct buffer string; ///< Parsed string value }; /// Input has to be null-terminated anyway @@ -266,12 +266,11 @@ lexer_init (struct lexer *self, const char *p, size_t len) { memset (self, 0, sizeof *self); self->p = p; self->len = len; - str_init (&self->string); } static void lexer_free (struct lexer *self) { - str_free (&self->string); + free (self->string.s); } static bool lexer_is_word_char (int c) { return !strchr ("()[]{}\n@#'", c); } @@ -289,33 +288,25 @@ lexer_advance (struct lexer *self) { return c; } -static void lexer_error (struct lexer *self, - struct error **e, const char *format, ...) ATTRIBUTE_PRINTF (3, 4); +static void lexer_error (struct lexer *self, char **e, const char *fmt, ...) + ATTRIBUTE_PRINTF (3, 4); +// TODO: see "script", we can just use error constants to avoid allocation static void -lexer_error (struct lexer *self, struct error **e, const char *format, ...) { - struct str description; - str_init (&description); - +lexer_error (struct lexer *self, char **e, const char *fmt, ...) { va_list ap; - va_start (ap, format); - str_append_vprintf (&description, format, ap); + va_start (ap, fmt); + char *description = vformat (fmt, ap); va_end (ap); - if (self->report_line) - error_set (e, "near line %u, column %u: %s", - self->line + 1, self->column + 1, description.str); - else if (self->len) - error_set (e, "near character %u: %s", - self->column + 1, description.str); - else - error_set (e, "near end: %s", description.str); + *e = format ("near line %u, column %u: %s", + self->line + 1, self->column + 1, description); - str_free (&description); + free (description); } static bool -lexer_hexa_escape (struct lexer *self, struct str *output) { +lexer_hexa_escape (struct lexer *self, struct buffer *output) { int i; unsigned char code = 0; @@ -334,20 +325,19 @@ lexer_hexa_escape (struct lexer *self, struct str *output) { if (!i) return false; - str_append_c (output, code); + buffer_append_c (output, code); return true; } static bool -lexer_escape_sequence - (struct lexer *self, struct str *output, struct error **e) { +lexer_escape_sequence (struct lexer *self, struct buffer *output, char **e) { if (!self->len) { lexer_error (self, e, "premature end of escape sequence"); return false; } - unsigned char c; - switch ((c = *self->p)) { + unsigned char c = *self->p; + switch (c) { case '"': break; case '\\': break; case 'a': c = '\a'; break; @@ -372,19 +362,19 @@ lexer_escape_sequence return false; } - str_append_c (output, c); + buffer_append_c (output, c); lexer_advance (self); return true; } static bool -lexer_string (struct lexer *self, struct str *output, struct error **e) { +lexer_string (struct lexer *self, struct buffer *output, char **e) { unsigned char c; while (self->len) { if ((c = lexer_advance (self)) == '\'') return true; if (c != '\\') - str_append_c (output, c); + buffer_append_c (output, c); else if (!lexer_escape_sequence (self, output, e)) return false; } @@ -393,13 +383,16 @@ lexer_string (struct lexer *self, struct str *output, struct error **e) { } static enum token -lexer_next (struct lexer *self, struct error **e) { +lexer_next (struct lexer *self, char **e) { // Skip over any whitespace between tokens - while (self->len && isspace_ascii (*self->p) && *self->p != '\n') + while (self->len && isspace (*self->p) && *self->p != '\n') lexer_advance (self); if (!self->len) return T_ABORT; + free (self->string.s); + self->string = (struct buffer) BUFFER_INITIALIZER; + switch (*self->p) { case '(': lexer_advance (self); return T_LPAREN; case ')': lexer_advance (self); return T_RPAREN; @@ -419,232 +412,24 @@ lexer_next (struct lexer *self, struct error **e) { case '\'': lexer_advance (self); - str_reset (&self->string); if (!lexer_string (self, &self->string, e)) return T_ABORT; return T_STRING; } assert (lexer_is_word_char (*self->p)); - str_reset (&self->string); do - str_append_c (&self->string, lexer_advance (self)); + buffer_append_c (&self->string, lexer_advance (self)); while (lexer_is_word_char (*self->p)); return T_STRING; } // --- Parsing ----------------------------------------------------------------- -#define PARSE_ERROR_TABLE(XX) \ - XX( OK, NULL ) \ - XX( EOF, "unexpected end of input" ) \ - XX( INVALID_HEXA_ESCAPE, "invalid hexadecimal escape sequence" ) \ - XX( INVALID_ESCAPE, "unrecognized escape sequence" ) \ - XX( MEMORY, "memory allocation failure" ) \ - XX( FLOAT_RANGE, "floating point value out of range" ) \ - XX( INTEGER_RANGE, "integer out of range" ) \ - XX( INVALID_INPUT, "invalid input" ) \ - XX( UNEXPECTED_INPUT, "unexpected input" ) - -enum tokenizer_error { -#define XX(x, y) PARSE_ERROR_ ## x, - PARSE_ERROR_TABLE (XX) -#undef XX - PARSE_ERROR_COUNT -}; - -struct tokenizer { - const char *cursor; - enum tokenizer_error error; -}; - -static bool -decode_hexa_escape (struct tokenizer *self, struct buffer *buf) { - int i; - char c, code = 0; - - for (i = 0; i < 2; i++) { - c = tolower (*self->cursor); - if (c >= '0' && c <= '9') - code = (code << 4) | (c - '0'); - else if (c >= 'a' && c <= 'f') - code = (code << 4) | (c - 'a' + 10); - else - break; - - self->cursor++; - } - - if (!i) - return false; - - buffer_append_c (buf, code); - return true; -} - -static bool -decode_escape_sequence (struct tokenizer *self, struct buffer *buf) { - // Support some basic escape sequences from the C language - char c; - switch ((c = *self->cursor)) { - case '\0': - self->error = PARSE_ERROR_EOF; - return false; - case 'x': - case 'X': - self->cursor++; - if (decode_hexa_escape (self, buf)) - return true; - - self->error = PARSE_ERROR_INVALID_HEXA_ESCAPE; - return false; - default: - self->cursor++; - const char *from = "abfnrtv\"\\", *to = "\a\b\f\n\r\t\v\"\\", *x; - if ((x = strchr (from, c))) { - buffer_append_c (buf, to[x - from]); - return true; - } - self->error = PARSE_ERROR_INVALID_ESCAPE; - return false; - } -} - -static struct item * -parse_string (struct tokenizer *self) { - struct buffer buf = BUFFER_INITIALIZER; - struct item *item = NULL; - char c; - - while (true) - switch ((c = *self->cursor++)) { - case '\0': - self->cursor--; - self->error = PARSE_ERROR_EOF; - goto end; - case '"': - if (buf.memory_failure - || !(item = new_string (buf.s, buf.len))) - self->error = PARSE_ERROR_MEMORY; - goto end; - case '\\': - if (decode_escape_sequence (self, &buf)) - break; - goto end; - default: - buffer_append_c (&buf, c); - } - -end: - free (buf.s); - return item; -} - -static struct item * -parse_word (struct tokenizer *self) { - struct buffer buf = BUFFER_INITIALIZER; - struct item *item = NULL; - char c; - - // Here we accept almost anything that doesn't break the grammar - while (!strchr (" []\"", (c = *self->cursor++)) && (unsigned char) c > ' ') - buffer_append_c (&buf, c); - self->cursor--; - - if (buf.memory_failure) - self->error = PARSE_ERROR_MEMORY; - else if (!buf.len) - self->error = PARSE_ERROR_INVALID_INPUT; - else if (!(item = new_word (buf.s, buf.len))) - self->error = PARSE_ERROR_MEMORY; - - free (buf.s); - return item; -} - -static struct item *parse_item_list (struct tokenizer *); - -static struct item * -parse_list (struct tokenizer *self) { - struct item *list = parse_item_list (self); - if (self->error) { - assert (list == NULL); - return NULL; - } - if (!*self->cursor) { - self->error = PARSE_ERROR_EOF; - item_free_list (list); - return NULL; - } - assert (*self->cursor == ']'); - self->cursor++; - return new_list (list); -} - -static struct item * -parse_item (struct tokenizer *self) { - char c; - switch ((c = *self->cursor++)) { - case '[': return parse_list (self); - case '"': return parse_string (self); - default:; - } - - self->cursor--; - return parse_word (self); -} - -static struct item * -parse_item_list (struct tokenizer *self) { - struct item *head = NULL; - struct item **tail = &head; - - char c; - bool expected = true; - while ((c = *self->cursor) && c != ']') { - if (isspace (c)) { - self->cursor++; - expected = true; - continue; - } else if (!expected) { - self->error = PARSE_ERROR_UNEXPECTED_INPUT; - goto fail; - } - - if (!(*tail = parse_item (self))) - goto fail; - tail = &(*tail)->next; - expected = false; - } - return head; - -fail: - item_free_list (head); - return NULL; -} - static struct item * parse (const char *s, const char **error) { - struct tokenizer self = { .cursor = s, .error = PARSE_ERROR_OK }; - struct item *list = parse_item_list (&self); - if (!self.error && *self.cursor != '\0') { - self.error = PARSE_ERROR_UNEXPECTED_INPUT; - item_free_list (list); - list = NULL; - } - -#define XX(x, y) y, - static const char *strings[PARSE_ERROR_COUNT] = - { PARSE_ERROR_TABLE (XX) }; -#undef XX - - static char error_buf[128]; - if (self.error && error) { - snprintf (error_buf, sizeof error_buf, "at character %d: %s", - (int) (self.cursor - s) + 1, strings[self.error]); - *error = error_buf; - } - return list; + // TODO + return NULL; } // --- Runtime ----------------------------------------------------------------- @@ -700,7 +485,7 @@ set_error (struct context *ctx, const char *format, ...) { va_list ap; va_start (ap, format); - ctx->error = strdup_vprintf (format, ap); + ctx->error = vformat (format, ap); va_end (ap); if (!ctx->error) @@ -807,7 +592,7 @@ execute (struct context *ctx, struct item *script) { if (!push (ctx, new_clone (script))) return false; } - else if (!call_function (ctx, get_word (script))) + else if (!call_function (ctx, script->value)) return false; } return true; @@ -827,7 +612,7 @@ init_runtime_library_scripts (void) { const char *name; ///< Name of the function const char *definition; ///< The defining script } scripts[] = { - { "greet", "print (.. 'hello ' (.. @1))" }, + { "greet", "arg _name \n print (.. 'hello ' (.. @_name))" }, }; for (size_t i = 0; i < N_ELEMENTS (scripts); i++) { @@ -870,8 +655,8 @@ defn (fn_concatenate) { static bool init_runtime_library (void) { - return register_handler ("..", fn_concatenate); - && register_handler ("print", fn_print); + return register_handler ("..", fn_concatenate) + && register_handler ("print", fn_print) && init_runtime_library_scripts (); } @@ -893,12 +678,12 @@ process_message (const char *msg) { struct item *script = parse (msg, &error); if (error) { printf ("%s: %s\r\n", "parse error", error); - goto end; + return; } struct context ctx; context_init (&ctx); - ctx.user_data = &info; + ctx.user_data = NULL; execute (&ctx, script); item_free_list (script); @@ -910,17 +695,11 @@ process_message (const char *msg) { if (failure) printf ("%s: %s\r\n", "runtime error", failure); context_free (&ctx); -end: - free (msg_ctx_quote); } int main (int argc, char *argv[]) { - freopen (NULL, "rb", stdin); setvbuf (stdin, NULL, _IOLBF, BUFSIZ); - freopen (NULL, "wb", stdout); setvbuf (stdout, NULL, _IOLBF, BUFSIZ); - - if (!init_runtime_library () - || !register_handler (".", fn_dot)) + if (!init_runtime_library ()) printf ("%s\n", "runtime library initialization failed"); // TODO: load the entirety of stdin and execute it