actions: implement -verbose_action option

Add an action option that prints the result of evaluating
the associated expression, annotating the result of evaluating each
atom (test operation) with =True or =False.

This can be used (especially in debugging action statements) to
show which action statements triggered, and why, and which
action statements didn't trigger and again why.

For instance given the action

-verbose_action 'uid(root)@type(d)||name(file*)'

This could produce the following output

test2/empty=uid(root)@(type(d)=True)
test2/file9=uid(root)@(type(d)=False||name(file*)=True)
test2/file4=uid(root)@(type(d)=False||name(file*)=True)
test2/a=uid(root)@(type(d)=False||name(file*)=False)
test2/sym=uid(root)@(type(d)=False||name(file*)=False)
test2/dir=uid(root)@(type(d)=True)
test2/dir/fred=uid(root)@(type(d)=False||name(file*)=False)
test2/file8=uid(root)@(type(d)=False||name(file*)=True)
test2=uid(root)@(type(d)=True)

Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>

3 files changed, 226 insertions, 47 deletions

diff --git a/squashfs-tools/action.c b/squashfs-tools/action.c
index d986b2a..cce2766 100644
--- a/squashfs-tools/action.c
+++ b/squashfs-tools/action.c
@@ -435,7 +435,7 @@ static struct expr *parse_expr(int subexp)
 /*
  * Action parser
  */
-int parse_action(char *s)
+int parse_action(char *s, int verbose)
 {
 	char *string, **argv = NULL;
 	int i, token, args = 0;
@@ -583,6 +583,7 @@ skip_args:
 	(*spec_list)[spec_count].argv = argv;
 	(*spec_list)[spec_count].expr = expr;
 	(*spec_list)[spec_count].data = data;
+	(*spec_list)[spec_count].verbose = verbose;
 
 	return 1;
 
@@ -595,6 +596,127 @@ failed:
 /*
  * Evaluate expressions
  */
+
+#define ALLOC_SZ 128
+
+#define LOG_ENABLE	0
+#define LOG_DISABLE	1
+#define LOG_PRINT	2
+#define LOG_ENABLED	3
+
+char *_expr_log(char *string, int cmnd)
+{
+	static char *expr_msg = NULL;
+	static int cur_size = 0, alloc_size = 0;
+	int size;
+
+	switch(cmnd) {
+	case LOG_ENABLE:
+		expr_msg = malloc(ALLOC_SZ);
+		alloc_size = ALLOC_SZ;
+		cur_size = 0;
+		return expr_msg;
+	case LOG_DISABLE:
+		free(expr_msg);
+		alloc_size = cur_size = 0;
+		return expr_msg = NULL;
+	case LOG_ENABLED:
+		return expr_msg;
+	default:
+		if(expr_msg == NULL)
+			return NULL;
+		break;
+	}
+
+	/* if string is empty append '\0' */
+	size = strlen(string) ? : 1; 
+
+	if(alloc_size - cur_size < size) {
+		/* buffer too small, expand */
+		alloc_size = (cur_size + size + ALLOC_SZ - 1) & ~(ALLOC_SZ - 1);
+
+		expr_msg = realloc(expr_msg, alloc_size);
+		if(expr_msg == NULL)
+			MEM_ERROR();
+	}
+
+	memcpy(expr_msg + cur_size, string, size);
+	cur_size += size; 
+
+	return expr_msg;
+}
+
+
+char *expr_log_cmnd(int cmnd)
+{
+	return _expr_log(NULL, cmnd);
+}
+
+
+char *expr_log(char *string)
+{
+	return _expr_log(string, LOG_PRINT);
+}
+
+
+void expr_log_atom(struct atom *atom)
+{
+	int i;
+
+	if(atom->test->handle_logging)
+		return;
+
+	expr_log(atom->test->name);
+	expr_log("(");
+	for(i = 0; i < atom->test->args; i++) {
+		expr_log(atom->argv[i]);
+		if (i + 1 < atom->test->args)
+			expr_log(",");
+	}
+	expr_log(")");
+}
+
+
+void expr_log_match(struct atom *atom, int match)
+{
+	if(match)
+		expr_log("=True");
+	else
+		expr_log("=False");
+}
+
+
+static int eval_expr_log(struct expr *expr, struct action_data *action_data)
+{
+	int match;
+
+	switch (expr->type) {
+	case ATOM_TYPE:
+		expr_log_atom(&expr->atom);
+		match = expr->atom.test->fn(&expr->atom, action_data);
+		expr_log_match(&expr->atom, match);
+		break;
+	case UNARY_TYPE:
+		expr_log("!");
+		match = !eval_expr_log(expr->unary_op.expr, action_data);
+		break;
+	default:
+		expr_log("(");
+		match = eval_expr_log(expr->expr_op.lhs, action_data);
+
+		if ((expr->expr_op.op == TOK_AND && match) ||
+				(expr->expr_op.op == TOK_OR && !match)) {
+			expr_log(token_table[expr->expr_op.op].string);
+			match = eval_expr_log(expr->expr_op.rhs, action_data);
+		}
+		expr_log(")");
+		break;
+	}
+
+	return match;
+}
+
+
 static int eval_expr(struct expr *expr, struct action_data *action_data)
 {
 	int match;
@@ -619,6 +741,44 @@ static int eval_expr(struct expr *expr, struct action_data *action_data)
 }
 
 
+static int eval_expr_top(struct action *action, struct action_data *action_data)
+{
+	if(action->verbose) {
+		int match, n;
+
+		expr_log_cmnd(LOG_ENABLE);
+
+		if(action_data->pathname)
+			expr_log(action_data->pathname);
+
+		expr_log("=");
+		expr_log(action->action->name);
+
+		if(action->action->args) {
+			expr_log("(");
+			for (n = 0; n < action->action->args; n++) {
+				expr_log(action->argv[n]);
+				if(n + 1 < action->action->args)
+					expr_log(",");
+			}
+			expr_log(")");
+		}
+
+		expr_log("@");
+
+		match = eval_expr_log(action->expr, action_data);
+
+		/* Print the evaluated expression log */
+		progressbar_info("%s\n", expr_log(""));
+
+		expr_log_cmnd(LOG_DISABLE);
+
+		return match;
+	} else
+		return eval_expr(action->expr, action_data);
+}
+
+
 /*
  * Read action file, passing each line to parse_action() for
  * parsing.
@@ -630,9 +790,15 @@ static int eval_expr(struct expr *expr, struct action_data *action_data)
  * 
  * Blank lines and comment lines indicated by # are supported.
  */
+int parse_action_nonverbose(char *s)
+{
+	return parse_action(s, 0);
+}
+
+
 int read_action_file(char *filename)
 {
-	return read_file(filename, "action", parse_action);
+	return read_file(filename, "action", parse_action_nonverbose);
 }
 
 
@@ -689,7 +855,7 @@ void eval_actions(struct dir_info *root, struct dir_ent *dir_ent)
 			/* action does not operate on this file type */
 			continue;
 
-		match = eval_expr(action->expr, &action_data);
+		match = eval_expr_top(action, &action_data);
 
 		if (match)
 			action->action->run_action(action, dir_ent);
@@ -717,7 +883,7 @@ void *eval_frag_actions(struct dir_info *root, struct dir_ent *dir_ent)
 	action_data.root = root;
 
 	for (i = 0; i < fragment_count; i++) {
-		match = eval_expr(fragment_spec[i].expr, &action_data);
+		match = eval_expr_top(&fragment_spec[i], &action_data);
 		if (match) {
 			free(action_data.pathname);
 			free(action_data.subpath);
@@ -777,7 +943,7 @@ int eval_exclude_actions(char *name, char *pathname, char *subpath,
 	action_data.dir_ent = dir_ent;
 
 	for (i = 0; i < exclude_count && !match; i++)
-		match = eval_expr(exclude_spec[i].expr, &action_data);
+		match = eval_expr_top(&exclude_spec[i], &action_data);
 
 	return match;
 }
@@ -1317,7 +1483,7 @@ int eval_empty_actions(struct dir_info *root, struct dir_ent *dir_ent)
 				(data->val == EMPTY_SOURCE && dir->excluded))
 			continue;
 		
-		match = eval_expr(empty_spec[i].expr, &action_data);
+		match = eval_expr_top(&empty_spec[i], &action_data);
 	}
 
 	free(action_data.pathname);
@@ -1551,7 +1717,7 @@ void eval_move_actions(struct dir_info *root, struct dir_ent *dir_ent)
 	 */
 	for (i = 0; i < move_count; i++) {
 		struct action *action = &move_spec[i];
-		int match = eval_expr(action->expr, &action_data);
+		int match = eval_expr_top(action, &action_data);
 
 		if(match) {
 			if(move == NULL) {
@@ -1765,7 +1931,7 @@ int eval_prune_actions(struct dir_info *root, struct dir_ent *dir_ent)
 	action_data.root = root;
 
 	for (i = 0; i < prune_count && !match; i++)
-		match = eval_expr(prune_spec[i].expr, &action_data);
+		match = eval_expr_top(&prune_spec[i], &action_data);
 
 	free(action_data.pathname);
 	free(action_data.subpath);
@@ -2822,42 +2988,42 @@ void dump_actions()
 
 static struct test_entry test_table[] = {
 	{ "name", 1, name_fn, NULL, 1},
-	{ "pathname", 1, pathname_fn, check_pathname, 1},
-	{ "subpathname", 1, subpathname_fn, check_pathname, 1},
-	{ "filesize", 1, filesize_fn, parse_number_arg, 1},
-	{ "dirsize", 1, dirsize_fn, parse_number_arg, 1},
-	{ "size", 1, size_fn, parse_number_arg, 1},
-	{ "inode", 1, inode_fn, parse_number_arg, 1},
-	{ "nlink", 1, nlink_fn, parse_number_arg, 1},
-	{ "fileblocks", 1, fileblocks_fn, parse_number_arg, 1},
-	{ "dirblocks", 1, dirblocks_fn, parse_number_arg, 1},
-	{ "blocks", 1, blocks_fn, parse_number_arg, 1},
-	{ "gid", 1, gid_fn, parse_gid_arg, 1},
-	{ "uid", 1, uid_fn, parse_uid_arg, 1},
-	{ "depth", 1, depth_fn, parse_number_arg, 1},
-	{ "dircount", 1, dircount_fn, parse_number_arg, 0},
-	{ "filesize_range", 2, filesize_range_fn, parse_range_args, 1},
-	{ "dirsize_range", 2, dirsize_range_fn, parse_range_args, 1},
-	{ "size_range", 2, size_range_fn, parse_range_args, 1},
-	{ "inode_range", 2, inode_range_fn, parse_range_args, 1},
-	{ "nlink_range", 2, nlink_range_fn, parse_range_args, 1},
-	{ "fileblocks_range", 2, fileblocks_range_fn, parse_range_args, 1},
-	{ "dirblocks_range", 2, dirblocks_range_fn, parse_range_args, 1},
-	{ "blocks_range", 2, blocks_range_fn, parse_range_args, 1},
-	{ "gid_range", 2, gid_range_fn, parse_range_args, 1},
-	{ "uid_range", 2, uid_range_fn, parse_range_args, 1},
-	{ "depth_range", 2, depth_range_fn, parse_range_args, 1},
-	{ "dircount_range", 2, dircount_range_fn, parse_range_args, 0},
-	{ "type", 1, type_fn, parse_type_arg, 1},
-	{ "true", 0, true_fn, NULL, 1},
-	{ "false", 0, false_fn, NULL, 1},
-	{ "file", 1, file_fn, parse_file_arg, 1},
-	{ "exec", 1, exec_fn, NULL, 1},
-	{ "exists", 0, exists_fn, NULL, 0},
-	{ "absolute", 0, absolute_fn, NULL, 0},
-	{ "stat", 1, stat_fn, parse_expr_arg0, 1},
-	{ "readlink", 1, readlink_fn, parse_expr_arg0, 0},
-	{ "eval", 2, eval_fn, parse_expr_arg1, 0},
+	{ "pathname", 1, pathname_fn, check_pathname, 1, 0},
+	{ "subpathname", 1, subpathname_fn, check_pathname, 1, 0},
+	{ "filesize", 1, filesize_fn, parse_number_arg, 1, 0},
+	{ "dirsize", 1, dirsize_fn, parse_number_arg, 1, 0},
+	{ "size", 1, size_fn, parse_number_arg, 1, 0},
+	{ "inode", 1, inode_fn, parse_number_arg, 1, 0},
+	{ "nlink", 1, nlink_fn, parse_number_arg, 1, 0},
+	{ "fileblocks", 1, fileblocks_fn, parse_number_arg, 1, 0},
+	{ "dirblocks", 1, dirblocks_fn, parse_number_arg, 1, 0},
+	{ "blocks", 1, blocks_fn, parse_number_arg, 1, 0},
+	{ "gid", 1, gid_fn, parse_gid_arg, 1, 0},
+	{ "uid", 1, uid_fn, parse_uid_arg, 1, 0},
+	{ "depth", 1, depth_fn, parse_number_arg, 1, 0},
+	{ "dircount", 1, dircount_fn, parse_number_arg, 0, 0},
+	{ "filesize_range", 2, filesize_range_fn, parse_range_args, 1, 0},
+	{ "dirsize_range", 2, dirsize_range_fn, parse_range_args, 1, 0},
+	{ "size_range", 2, size_range_fn, parse_range_args, 1, 0},
+	{ "inode_range", 2, inode_range_fn, parse_range_args, 1, 0},
+	{ "nlink_range", 2, nlink_range_fn, parse_range_args, 1, 0},
+	{ "fileblocks_range", 2, fileblocks_range_fn, parse_range_args, 1, 0},
+	{ "dirblocks_range", 2, dirblocks_range_fn, parse_range_args, 1, 0},
+	{ "blocks_range", 2, blocks_range_fn, parse_range_args, 1, 0},
+	{ "gid_range", 2, gid_range_fn, parse_range_args, 1, 0},
+	{ "uid_range", 2, uid_range_fn, parse_range_args, 1, 0},
+	{ "depth_range", 2, depth_range_fn, parse_range_args, 1, 0},
+	{ "dircount_range", 2, dircount_range_fn, parse_range_args, 0, 0},
+	{ "type", 1, type_fn, parse_type_arg, 1, 0},
+	{ "true", 0, true_fn, NULL, 1, 0},
+	{ "false", 0, false_fn, NULL, 1, 0},
+	{ "file", 1, file_fn, parse_file_arg, 1, 0},
+	{ "exec", 1, exec_fn, NULL, 1, 0},
+	{ "exists", 0, exists_fn, NULL, 0, 0},
+	{ "absolute", 0, absolute_fn, NULL, 0, 0},
+	{ "stat", 1, stat_fn, parse_expr_arg0, 1, 1},
+	{ "readlink", 1, readlink_fn, parse_expr_arg0, 0, 1},
+	{ "eval", 2, eval_fn, parse_expr_arg1, 0, 1},
 	{ "", -1 }
 };
 
diff --git a/squashfs-tools/action.h b/squashfs-tools/action.h
index 6b9e4dd..f8099f7 100644
--- a/squashfs-tools/action.h
+++ b/squashfs-tools/action.h
@@ -144,6 +144,7 @@ struct test_entry {
 	int (*fn)(struct atom *, struct action_data *);
 	int (*parse_args)(struct test_entry *, struct atom *);
 	int exclude_ok;
+	int handle_logging;
 };
 
 
@@ -212,6 +213,7 @@ struct action {
 	char **argv;
 	struct expr *expr;
 	void *data;
+	int verbose;
 };
 
 
@@ -279,7 +281,7 @@ struct move_ent {
 /*
  * External function definitions
  */
-extern int parse_action(char *);
+extern int parse_action(char *, int verbose);
 extern void dump_actions();
 extern void *eval_frag_actions(struct dir_info *, struct dir_ent *);
 extern void *get_frag_action(void *);
diff --git a/squashfs-tools/mksquashfs.c b/squashfs-tools/mksquashfs.c
index 372af06..346ab83 100644
--- a/squashfs-tools/mksquashfs.c
+++ b/squashfs-tools/mksquashfs.c
@@ -5089,7 +5089,7 @@ void calculate_queue_sizes(int mem, int *readq, int *fragq, int *bwriteq,
 
 
 #define VERSION() \
-	printf("mksquashfs version 4.3-git (2014/08/10)\n");\
+	printf("mksquashfs version 4.3-git (2014/08/17)\n");\
 	printf("copyright (C) 2014 Phillip Lougher "\
 		"<phillip@squashfs.org.uk>\n\n"); \
 	printf("This program is free software; you can redistribute it and/or"\
@@ -5193,7 +5193,18 @@ int main(int argc, char *argv[])
 					argv[0], argv[i - 1]);
 				exit(1);
 			}
-			res = parse_action(argv[i]);
+			res = parse_action(argv[i], 0);
+			if(res == 0)
+				exit(1);
+
+		} else if(strcmp(argv[i], "-verbose_action") == 0 ||
+				strcmp(argv[i], "-va") ==0) {
+			if(++i == argc) {
+				ERROR("%s: %s missing action\n",
+					argv[0], argv[i - 1]);
+				exit(1);
+			}
+			res = parse_action(argv[i], 1);
 			if(res == 0)
 				exit(1);