Change the signature of sqfs_compressor_create to return an error code

Make sure the function has a way of telling the caller *why* it failed.

This way, the function can convey whether it had an internal error, an
allocation failure, whether the arguments are totaly nonsensical, or
simply that the compressor *or specific configuration* is not supported.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

4 files changed, 18 insertions, 16 deletions

diff --git a/extras/browse.c b/extras/browse.c
index 5b27dc6..9dd735a 100644
--- a/extras/browse.c
+++ b/extras/browse.c
@@ -477,10 +477,10 @@ static const struct {
 int main(int argc, char **argv)
 {
 	char *cmd, *arg, *buffer = NULL;
+	int ret, status = EXIT_FAILURE;
 	sqfs_compressor_config_t cfg;
 	sqfs_compressor_t *cmp;
 	sqfs_file_t *file;
-	int status = EXIT_FAILURE;
 	size_t i;
 
 	/* open the SquashFS file we want to read */
@@ -511,9 +511,10 @@ int main(int argc, char **argv)
 				    super.block_size,
 				    SQFS_COMP_FLAG_UNCOMPRESS);
 
-	cmp = sqfs_compressor_create(&cfg);
-	if (cmp == NULL) {
-		fprintf(stderr, "%s: error creating compressor.\n", argv[1]);
+	ret = sqfs_compressor_create(&cfg, &cmp);
+	if (ret != 0) {
+		fprintf(stderr, "%s: error creating compressor: %d.\n",
+			argv[1], ret);
 		goto out_fd;
 	}
 
diff --git a/extras/list_files.c b/extras/list_files.c
index 5e181f2..eba4fff 100644
--- a/extras/list_files.c
+++ b/extras/list_files.c
@@ -47,6 +47,7 @@ static void write_tree_dfs(const sqfs_tree_node_t *n)
 
 int main(int argc, char **argv)
 {
+	int ret, status = EXIT_FAILURE;
 	sqfs_compressor_config_t cfg;
 	sqfs_compressor_t *cmp;
 	sqfs_tree_node_t *root = NULL;
@@ -54,7 +55,6 @@ int main(int argc, char **argv)
 	sqfs_dir_reader_t *dr;
 	sqfs_file_t *file;
 	sqfs_super_t super;
-	int status = EXIT_FAILURE;
 
 	/* open the SquashFS file we want to read */
 	if (argc != 2) {
@@ -84,9 +84,10 @@ int main(int argc, char **argv)
 				    super.block_size,
 				    SQFS_COMP_FLAG_UNCOMPRESS);
 
-	cmp = sqfs_compressor_create(&cfg);
-	if (cmp == NULL) {
-		fprintf(stderr, "%s: error creating compressor.\n", argv[1]);
+	ret = sqfs_compressor_create(&cfg, &cmp);
+	if (ret != 0) {
+		fprintf(stderr, "%s: error creating compressor: %d.\n",
+			argv[1], ret);
 		goto out_fd;
 	}
 
diff --git a/extras/mk42sqfs.c b/extras/mk42sqfs.c
index e7c5357..92323e0 100644
--- a/extras/mk42sqfs.c
+++ b/extras/mk42sqfs.c
@@ -50,10 +50,10 @@ static sqfs_inode_generic_t *create_file_inode(sqfs_id_table_t *idtbl,
 int main(void)
 {
 	sqfs_meta_writer_t *inode_m, *dir_m;
+	int ret, status = EXIT_FAILURE;
 	sqfs_compressor_config_t cfg;
 	sqfs_inode_generic_t *inode;
 	unsigned int i, inode_num;
-	int status = EXIT_FAILURE;
 	sqfs_dir_writer_t *dirwr;
 	sqfs_compressor_t *cmp;
 	sqfs_id_table_t *idtbl;
@@ -88,9 +88,9 @@ int main(void)
 	sqfs_compressor_config_init(&cfg, super.compression_id,
 				    super.block_size, 0);
 
-	cmp = sqfs_compressor_create(&cfg);
-	if (cmp == NULL) {
-		fputs("Error creating compressor.\n", stderr);
+	ret = sqfs_compressor_create(&cfg, &cmp);
+	if (ret != 0) {
+		fprintf(stderr, "Error creating compressor: %d.\n", ret);
 		goto out_file;
 	}
 
diff --git a/extras/mknastyfs.c b/extras/mknastyfs.c
index 7ec3ee0..daadf37 100644
--- a/extras/mknastyfs.c
+++ b/extras/mknastyfs.c
@@ -46,9 +46,9 @@ static sqfs_inode_generic_t *create_file_inode(sqfs_id_table_t *idtbl,
 int main(void)
 {
 	sqfs_meta_writer_t *inode_m, *dir_m;
+	int ret, status = EXIT_FAILURE;
 	sqfs_compressor_config_t cfg;
 	sqfs_inode_generic_t *inode;
-	int status = EXIT_FAILURE;
 	sqfs_dir_writer_t *dirwr;
 	sqfs_compressor_t *cmp;
 	sqfs_id_table_t *idtbl;
@@ -77,9 +77,9 @@ int main(void)
 	sqfs_compressor_config_init(&cfg, super.compression_id,
 				    super.block_size, 0);
 
-	cmp = sqfs_compressor_create(&cfg);
-	if (cmp == NULL) {
-		fputs("Error creating compressor.\n", stderr);
+	ret = sqfs_compressor_create(&cfg, &cmp);
+	if (ret != 0) {
+		fprintf(stderr, "Error creating compressor: %d.\n", ret);
 		goto out_file;
 	}