X-Git-Url: https://git.sur5r.net/?a=blobdiff_plain;f=src%2Fcommands_parser.c;h=fa4c2360101513e4796490c9720ff9b63533915f;hb=856e1f977299f26cdfb91ee2ef215455b1fba7a9;hp=1720fd6f0418d84fced2026d992f8049bca8fc89;hpb=c2b699f3dc4fb9ff4dfb2c7409bc9d031aeddf71;p=i3%2Fi3 diff --git a/src/commands_parser.c b/src/commands_parser.c index 1720fd6f..fa4c2360 100644 --- a/src/commands_parser.c +++ b/src/commands_parser.c @@ -13,7 +13,7 @@ * We use a hand-written parser instead of lex/yacc because our commands are * easy for humans, not for computers. Thus, it’s quite hard to specify a * context-free grammar for the commands. A PEG grammar would be easier, but - * there’s downsides to every PEG parser generator I have come accross so far. + * there’s downsides to every PEG parser generator I have come across so far. * * This parser is basically a state machine which looks for literals or strings * and can push either on a stack. After identifying a literal or string, it @@ -35,8 +35,8 @@ #include "all.h" // Macros to make the YAJL API a bit easier to use. -#define y(x, ...) yajl_gen_ ## x (command_output.json_gen, ##__VA_ARGS__) -#define ystr(str) yajl_gen_string(command_output.json_gen, (unsigned char*)str, strlen(str)) +#define y(x, ...) (command_output.json_gen != NULL ? yajl_gen_##x(command_output.json_gen, ##__VA_ARGS__) : 0) +#define ystr(str) (command_output.json_gen != NULL ? yajl_gen_string(command_output.json_gen, (unsigned char *)str, strlen(str)) : 0) /******************************************************************************* * The data structures used for parsing. Essentially the current state and a @@ -179,17 +179,17 @@ static cmdp_state state; #ifndef TEST_PARSER static Match current_match; #endif -static struct CommandResult subcommand_output; -static struct CommandResult command_output; +static struct CommandResultIR subcommand_output; +static struct CommandResultIR command_output; #include "GENERATED_command_call.h" - static void next_state(const cmdp_token *token) { if (token->next_state == __CALL) { subcommand_output.json_gen = command_output.json_gen; subcommand_output.needs_tree_render = false; GENERATED_call(token->extra.call_identifier, &subcommand_output); + state = subcommand_output.next_state; /* If any subcommand requires a tree_render(), we need to make the * whole parser result request a tree_render(). */ if (subcommand_output.needs_tree_render) @@ -204,16 +204,76 @@ static void next_state(const cmdp_token *token) { } } -struct CommandResult *parse_command(const char *input) { +/* + * Parses a string (or word, if as_word is true). Extracted out of + * parse_command so that it can be used in src/workspace.c for interpreting + * workspace commands. + * + */ +char *parse_string(const char **walk, bool as_word) { + const char *beginning = *walk; + /* Handle quoted strings (or words). */ + if (**walk == '"') { + beginning++; + (*walk)++; + for (; **walk != '\0' && **walk != '"'; (*walk)++) + if (**walk == '\\' && *(*walk + 1) != '\0') + (*walk)++; + } else { + if (!as_word) { + /* For a string (starting with 's'), the delimiters are + * comma (,) and semicolon (;) which introduce a new + * operation or command, respectively. Also, newlines + * end a command. */ + while (**walk != ';' && **walk != ',' && + **walk != '\0' && **walk != '\r' && + **walk != '\n') + (*walk)++; + } else { + /* For a word, the delimiters are white space (' ' or + * '\t'), closing square bracket (]), comma (,) and + * semicolon (;). */ + while (**walk != ' ' && **walk != '\t' && + **walk != ']' && **walk != ',' && + **walk != ';' && **walk != '\r' && + **walk != '\n' && **walk != '\0') + (*walk)++; + } + } + if (*walk == beginning) + return NULL; + + char *str = scalloc(*walk - beginning + 1); + /* We copy manually to handle escaping of characters. */ + int inpos, outpos; + for (inpos = 0, outpos = 0; + inpos < (*walk - beginning); + inpos++, outpos++) { + /* We only handle escaped double quotes and backslashes to not break + * backwards compatibility with people using \w in regular expressions + * etc. */ + if (beginning[inpos] == '\\' && (beginning[inpos + 1] == '"' || beginning[inpos + 1] == '\\')) + inpos++; + str[outpos] = beginning[inpos]; + } + + return str; +} + +/* + * Parses and executes the given command. If a caller-allocated yajl_gen is + * passed, a json reply will be generated in the format specified by the ipc + * protocol. Pass NULL if no json reply is required. + * + * Free the returned CommandResult with command_result_free(). + */ +CommandResult *parse_command(const char *input, yajl_gen gen) { DLOG("COMMAND: *%s*\n", input); state = INITIAL; + CommandResult *result = scalloc(sizeof(CommandResult)); -/* A YAJL JSON generator used for formatting replies. */ -#if YAJL_MAJOR >= 2 - command_output.json_gen = yajl_gen_alloc(NULL); -#else - command_output.json_gen = yajl_gen_alloc(NULL, NULL); -#endif + /* A YAJL JSON generator used for formatting replies. */ + command_output.json_gen = gen; y(array_open); command_output.needs_tree_render = false; @@ -224,17 +284,18 @@ struct CommandResult *parse_command(const char *input) { const cmdp_token *token; bool token_handled; - // TODO: make this testable +// TODO: make this testable #ifndef TEST_PARSER cmd_criteria_init(¤t_match, &subcommand_output); #endif /* The "<=" operator is intentional: We also handle the terminating 0-byte * explicitly by looking for an 'end' token. */ - while ((walk - input) <= len) { + while ((size_t)(walk - input) <= len) { /* skip whitespace and newlines before every token */ while ((*walk == ' ' || *walk == '\t' || - *walk == '\r' || *walk == '\n') && *walk != '\0') + *walk == '\r' || *walk == '\n') && + *walk != '\0') walk++; cmdp_token_ptr *ptr = &(tokens[state]); @@ -257,48 +318,8 @@ struct CommandResult *parse_command(const char *input) { if (strcmp(token->name, "string") == 0 || strcmp(token->name, "word") == 0) { - const char *beginning = walk; - /* Handle quoted strings (or words). */ - if (*walk == '"') { - beginning++; - walk++; - while (*walk != '\0' && (*walk != '"' || *(walk-1) == '\\')) - walk++; - } else { - if (token->name[0] == 's') { - /* For a string (starting with 's'), the delimiters are - * comma (,) and semicolon (;) which introduce a new - * operation or command, respectively. Also, newlines - * end a command. */ - while (*walk != ';' && *walk != ',' && - *walk != '\0' && *walk != '\r' && - *walk != '\n') - walk++; - } else { - /* For a word, the delimiters are white space (' ' or - * '\t'), closing square bracket (]), comma (,) and - * semicolon (;). */ - while (*walk != ' ' && *walk != '\t' && - *walk != ']' && *walk != ',' && - *walk != ';' && *walk != '\r' && - *walk != '\n' && *walk != '\0') - walk++; - } - } - if (walk != beginning) { - char *str = scalloc(walk-beginning + 1); - /* We copy manually to handle escaping of characters. */ - int inpos, outpos; - for (inpos = 0, outpos = 0; - inpos < (walk-beginning); - inpos++, outpos++) { - /* We only handle escaped double quotes to not break - * backwards compatibility with people using \w in - * regular expressions etc. */ - if (beginning[inpos] == '\\' && beginning[inpos+1] == '"') - inpos++; - str[outpos] = beginning[inpos]; - } + char *str = parse_string(&walk, (token->name[0] != 's')); + if (str != NULL) { if (token->identifier) push_string(token->identifier, str); /* If we are at the end of a quoted string, skip the ending @@ -315,19 +336,19 @@ struct CommandResult *parse_command(const char *input) { if (*walk == '\0' || *walk == ',' || *walk == ';') { next_state(token); token_handled = true; - /* To make sure we start with an appropriate matching +/* To make sure we start with an appropriate matching * datastructure for commands which do *not* specify any * criteria, we re-initialize the criteria system after * every command. */ - // TODO: make this testable +// TODO: make this testable #ifndef TEST_PARSER if (*walk == '\0' || *walk == ';') cmd_criteria_init(¤t_match, &subcommand_output); #endif walk++; break; - } - } + } + } } if (!token_handled) { @@ -381,6 +402,9 @@ struct CommandResult *parse_command(const char *input) { ELOG("Your command: %s\n", input); ELOG(" %s\n", position); + result->parse_error = true; + result->error_message = errormessage; + /* Format this error message as a JSON reply. */ y(map_open); ystr("success"); @@ -399,7 +423,6 @@ struct CommandResult *parse_command(const char *input) { y(map_close); free(position); - free(errormessage); clear_stack(); break; } @@ -407,7 +430,19 @@ struct CommandResult *parse_command(const char *input) { y(array_close); - return &command_output; + result->needs_tree_render = command_output.needs_tree_render; + return result; +} + +/* + * Frees a CommandResult + */ +void command_result_free(CommandResult *result) { + if (result == NULL) + return; + + FREE(result->error_message); + FREE(result); } /******************************************************************************* @@ -445,6 +480,12 @@ int main(int argc, char *argv[]) { fprintf(stderr, "Syntax: %s \n", argv[0]); return 1; } - parse_command(argv[1]); + yajl_gen gen = yajl_gen_alloc(NULL); + + CommandResult *result = parse_command(argv[1], gen); + + command_result_free(result); + + yajl_gen_free(gen); } #endif