X-Git-Url: http://git.ozlabs.org/?p=petitboot;a=blobdiff_plain;f=discover%2Fgrub2%2Fscript.c;h=48c963e7549c1982d45d1143895be4f301132e55;hp=e29d43702b1e0099435ab76b2f3966ad559cee90;hb=03eba1d68dbf7ffc9690d73f957c33b8f492e627;hpb=59dbd08e2a8354e71578c0d7ca2283951a384801

diff --git a/discover/grub2/script.c b/discover/grub2/script.c
index e29d437..48c963e 100644
--- a/discover/grub2/script.c
+++ b/discover/grub2/script.c
@@ -19,6 +19,8 @@
 	container_of(stmt, struct grub2_statement_menuentry, st)
 #define to_stmt_function(stmt) \
 	container_of(stmt, struct grub2_statement_function, st)
+#define to_stmt_for(stmt) \
+	container_of(stmt, struct grub2_statement_for, st)
 #define to_stmt_conditional(stmt) \
 	container_of(stmt, struct grub2_statement_conditional, st)
 
@@ -84,7 +86,7 @@ void script_env_set(struct grub2_script *script,
 	entry->value = talloc_strdup(entry, value);
 }
 
-static bool expand_var(struct grub2_script *script, struct grub2_word *word)
+static char *expand_var(struct grub2_script *script, struct grub2_word *word)
 {
 	const char *val;
 
@@ -92,9 +94,7 @@ static bool expand_var(struct grub2_script *script, struct grub2_word *word)
 	if (!val)
 		val = "";
 
-	word->text = talloc_strdup(script, val);
-
-	return true;
+	return talloc_strdup(script, val);
 }
 
 static bool is_delim(char c)
@@ -103,7 +103,7 @@ static bool is_delim(char c)
 }
 
 static bool option_is_default(struct grub2_script *script,
-		struct discover_boot_option *opt)
+		struct discover_boot_option *opt, const char *id)
 {
 	unsigned int default_idx;
 	const char *var;
@@ -117,128 +117,118 @@ static bool option_is_default(struct grub2_script *script,
 	if (end != var && *end == '\0')
 		return default_idx == script->n_options;
 
-	return !strcmp(opt->option->name, var);
+	/* if we don't have an explicit id for this option, fall back to
+	 * the name */
+	if (!id)
+		id = opt->option->name;
+
+	return !strcmp(id, var);
 }
 
-/* For non-double-quoted variable expansions, we may need to split the
- * variable's value into multiple argv items.
- *
- * This function sets the word->text to the initial set of non-delimiter chars
- * in the expanded var value. We then skip any delimiter chars, and (if
- * required), create the new argv item with the remaining text, and
- * add it to the argv list, after top_word.
- */
-static void process_split(struct grub2_script *script,
-		struct grub2_word *top_word,
-		struct grub2_word *word)
+static void append_text_to_current_arg(struct grub2_argv *argv,
+		const char *text, int len)
 {
-	int i, len, delim_start = -1, delim_end = -1;
-	struct grub2_word *new_word;
-	char *remainder;
+	char *cur = argv->argv[argv->argc - 1];
 
-	len = strlen(word->text);
+	if (cur) {
+		int curlen = strlen(cur);
+		cur = talloc_realloc(argv->argv, cur, char, len + curlen + 1);
+		memcpy(cur + curlen, text, len);
+		cur[len + curlen] = '\0';
 
-	/* Scan our string for the start of a delim (delim_start), and the
-	 * start of any new text (delim_end). */
-	for (i = 0; i < len; i++) {
-		if (is_delim(word->text[i])) {
-			if (delim_start == -1)
-				delim_start = i;
-		} else if (delim_start != -1) {
-			delim_end = i;
-			break;
-		}
+	} else {
+		cur = talloc_strndup(argv->argv, text, len);
 	}
 
-	/* No delim? nothing to do. The process_expansions loop will
-	 * append this word's text to the top word, if necessary
-	 */
-	if (delim_start == -1)
+	argv->argv[argv->argc-1] = cur;
+}
+
+/* Add a word to the argv array. Depending on the word type, and presence of
+ * delimiter characters, we may add multiple items to the array.
+ */
+static void append_word_to_argv(struct grub2_script *script,
+		struct grub2_argv *argv, struct grub2_word *word)
+{
+	const char *text, *pos;
+	int i, len;
+
+	/* If it's a variable, perform substitution */
+	if (word->type == GRUB2_WORD_VAR)
+		text = expand_var(script, word);
+	else
+		text = word->text;
+
+	len = strlen(text);
+
+	/* If we have no text, we leave the current word as-is. The caller
+	 * has allocated an empty string for the case where this is the
+	 * first text token */
+	if (!len)
 		return;
 
-	/* Set this word's text value to the text before the delimiter.
-	 * this will get appended to the top word
-	 */
-	word->text[delim_start] = '\0';
-
-	/* No trailing text? If there are no following word tokens, we're done.
-	 * Otherwise, we need to start a new argv item with those tokens */
-	if (delim_end == -1) {
-		if (!word->next)
-			return;
-		remainder = "";
-	} else {
-		remainder = word->text + delim_end;
+	/* If we're not splitting, we just add the entire block to the
+	 * current argv item */
+	if (!word->split) {
+		append_text_to_current_arg(argv, text, len);
+		return;
 	}
 
-	new_word = talloc(script, struct grub2_word);
-	new_word->type = GRUB2_WORD_TEXT;
-	/* if there's no trailing text, we know we don't need to re-split */
-	new_word->split = delim_end != -1;
-	new_word->next = word->next;
-	new_word->last = NULL;
-	new_word->text = talloc_strdup(new_word, remainder);
+	/* Scan for delimiters. If we find a word-end boundary, add the word
+	 * to the argv array, and start a new argv item */
+	pos = !is_delim(text[0]) ? text : NULL;
+	for (i = 0; i < len; i++) {
 
-	/* stitch it into the argv list before this word */
-	list_insert_after(&top_word->argv_list,
-			   &new_word->argv_list);
+		/* first delimiter after a word: add the accumulated word to
+		 * argv */
+		if (pos && is_delim(text[i])) {
+			append_text_to_current_arg(argv, pos,
+					text + i - pos);
+			pos = NULL;
+
+		/* first non-delimeter after a delimiter: record the starting
+		 * position, and create another argv item */
+		} else if (!pos && !is_delim(text[i])) {
+			pos = text + i;
+			argv->argc++;
+			argv->argv = talloc_realloc(argv, argv->argv, char *,
+					argv->argc);
+			argv->argv[argv->argc - 1] = NULL;
+		}
+	}
 
-	/* terminate this word */
-	word->next = NULL;
+	/* add remaining word characters */
+	if (pos)
+		append_text_to_current_arg(argv, pos, text + len - pos);
 }
 
-/* iterate through the words in an argv_list, looking for GRUB2_WORD_VAR
+/* Transform an argv word-token list (returned from the parser) into an
+ * expanded argv array (as used by the script execution code). We do this by
+ * iterating through the words in an argv_list, looking for GRUB2_WORD_VAR
  * expansions.
- *
- * Once that's done, we may (if split == true) have to split the word to create
- * new argv items
  */
 static void process_expansions(struct grub2_script *script,
 		struct grub2_argv *argv)
 {
 	struct grub2_word *top_word, *word;
-	int i;
 
 	argv->argc = 0;
+	argv->argv = NULL;
 
 	list_for_each_entry(&argv->words, top_word, argv_list) {
 		argv->argc++;
-
-		/* expand vars and squash the list of words into the head
-		 * of the argv word list */
-		for (word = top_word; word; word = word->next) {
-
-			/* if it's a variable, perform the substitution */
-			if (word->type == GRUB2_WORD_VAR) {
-				expand_var(script, word);
-				word->type = GRUB2_WORD_TEXT;
-			}
-
-			/* split; this will potentially insert argv
-			 * entries after top_word. */
-			if (word->split)
-				process_split(script, top_word, word);
-
-			/* accumulate word text into the top word, so
-			 * we end up with a shallow tree of argv data */
-			/* todo: don't do this in process_split */
-			if (word != top_word) {
-				top_word->text = talloc_asprintf_append(
-							top_word->text,
-							"%s", word->text);
-			}
-
-
-		}
-		top_word->next = NULL;
+		argv->argv = talloc_realloc(argv, argv->argv, char *,
+				argv->argc);
+		/* because we've parsed a separate word here, we know that
+		 * we need at least an empty string */
+		argv->argv[argv->argc - 1] = talloc_strdup(argv->argv, "");
+
+		for (word = top_word; word; word = word->next)
+			append_word_to_argv(script, argv, word);
 	}
 
-	/* convert the list to an argv array, to pass to the function */
-	argv->argv = talloc_array(script, char *, argv->argc);
-	i = 0;
-
-	list_for_each_entry(&argv->words, word, argv_list)
-		argv->argv[i++] = word->text;
+	/* we may have allocated an extra argv element but not populated it */
+	if (!argv->argv[argv->argc - 1])
+		argv->argc--;
 }
 
 static int statements_execute(struct grub2_script *script,
@@ -319,7 +309,7 @@ int statement_if_execute(struct grub2_script *script,
 {
 	struct grub2_statement_if *st = to_stmt_if(statement);
 	struct grub2_statement *conditional;
-	bool executed;
+	bool executed = false;
 	int rc = 0;
 
 	list_for_each_entry(&st->conditionals->list, conditional, list) {
@@ -340,26 +330,41 @@ int statement_menuentry_execute(struct grub2_script *script,
 {
 	struct grub2_statement_menuentry *st = to_stmt_menuentry(statement);
 	struct discover_boot_option *opt;
+	const char *id = NULL;
+	int i;
 
 	process_expansions(script, st->argv);
 
 	opt = discover_boot_option_create(script->ctx, script->ctx->device);
-	if (st->argv->argc > 0) {
+
+	/* XXX: --options=values need to be parsed properly; this is a simple
+	 * implementation to get --id= working.
+	 */
+	for (i = 1; i < st->argv->argc; ++i) {
+		if (strncmp("--id=", st->argv->argv[i], 5) == 0) {
+			id = st->argv->argv[i] + 5;
+			break;
+		}
+	}
+	if (st->argv->argc > 0)
 		opt->option->name = talloc_strdup(opt, st->argv->argv[0]);
-	} else {
+	else
 		opt->option->name = talloc_strdup(opt, "(unknown)");
-	}
+
 	opt->option->id = talloc_asprintf(opt->option, "%s#%s",
 			script->ctx->device->device->id,
-			opt->option->name);
+			id ? id : opt->option->name);
 
 	script->opt = opt;
 
 	statements_execute(script, st->statements);
 
-	opt->option->is_default = option_is_default(script, opt);
+	if (!opt->boot_image)
+		return -1;
 
-	discover_context_add_boot_option(script->ctx, opt);
+	opt->option->is_default = option_is_default(script, opt, id);
+
+	list_add_tail(&script->options, &opt->list);
 	script->n_options++;
 	script->opt = NULL;
 
@@ -375,7 +380,7 @@ static int function_invoke(struct grub2_script *script,
 
 	/* set positional parameters */
 	for (i = 0; i < argc; i++) {
-		name = talloc_asprintf(script, "$%d", i);
+		name = talloc_asprintf(script, "%d", i);
 		script_env_set(script, name, argv[i]);
 	}
 
@@ -389,25 +394,60 @@ int statement_function_execute(struct grub2_script *script,
 	const char *name;
 
 	if (st->name->type == GRUB2_WORD_VAR)
-		expand_var(script, st->name);
+		name = expand_var(script, st->name);
+	else
+		name = st->name->text;
 
-	name = st->name->text;
 	script_register_function(script, name, function_invoke, st);
 
 	return 0;
 }
 
+int statement_for_execute(struct grub2_script *script,
+		struct grub2_statement *statement)
+{
+	struct grub2_statement_for *st = to_stmt_for(statement);
+	const char *varname;
+	int i, rc = 0;
+
+	if (st->var->type == GRUB2_WORD_VAR)
+		expand_var(script, st->var);
+	varname = st->var->text;
+
+	process_expansions(script, st->list);
+
+	for (i = 0; i < st->list->argc; ++i) {
+		script_env_set(script, varname, st->list->argv[i]);
+		rc = statements_execute(script, st->body);
+	}
+
+	return rc;
+}
+
 static void init_env(struct grub2_script *script)
 {
 	struct env_entry *env;
+	char *prefix, *sep;
 
 	list_init(&script->environment);
 
+	/* use location of the parsed config file to determine the prefix */
 	env = talloc(script, struct env_entry);
-	env->name = talloc_strdup(env, "prefix");
-	env->value = talloc_strdup(env, default_prefix);
 
-	list_add(&script->environment, &env->list);
+	prefix = NULL;
+	if (script->filename) {
+		sep = strrchr(script->filename, '/');
+		if (sep)
+			prefix = talloc_strndup(env, script->filename,
+					sep - script->filename);
+	}
+
+	script_env_set(script, "prefix", prefix ? : default_prefix);
+	if (prefix)
+		talloc_free(prefix);
+
+	/* establish feature settings */
+	script_env_set(script, "feature_menuentry_id", "y");
 }
 
 void script_register_function(struct grub2_script *script,
@@ -423,10 +463,43 @@ void script_register_function(struct grub2_script *script,
 	list_add(&script->symtab, &entry->list);
 }
 
+static void set_fallback_default(struct grub2_script *script)
+{
+	struct discover_boot_option *opt, *first = NULL;
+	bool have_default = false;
+
+	list_for_each_entry(&script->options, opt, list) {
+		if (!first)
+			first = opt;
+		have_default = have_default || opt->option->is_default;
+	}
+
+	if (!have_default && first) {
+		const char *env = script_env_get(script, "default");
+
+		pb_log("grub: no explicit default (env default=%s), "
+				"falling back to first option (%s)\n",
+				env ?: "unset", first->option->name);
+
+		first->option->is_default = true;
+	}
+}
 
 void script_execute(struct grub2_script *script)
 {
+	struct discover_boot_option *opt, *tmp;
+
+	init_env(script);
 	statements_execute(script, script->statements);
+
+	set_fallback_default(script);
+
+	list_for_each_entry_safe(&script->options, opt, tmp, list)
+		discover_context_add_boot_option(script->ctx, opt);
+
+	/* Our option list will be invalid, as we've added all options to the
+	 * discover context */
+	list_init(&script->options);
 }
 
 struct grub2_script *create_script(struct grub2_parser *parser,
@@ -436,10 +509,10 @@ struct grub2_script *create_script(struct grub2_parser *parser,
 
 	script = talloc_zero(parser, struct grub2_script);
 
-	init_env(script);
 	script->ctx = ctx;
 
 	list_init(&script->symtab);
+	list_init(&script->options);
 	register_builtins(script);
 
 	return script;