core: simplify consumer, label & name strings handling

The separate buffers make the code less readable for no real benefit.

Remove them and simplify the strings handling. Also: improve the way
we're handling the chip names and labels.

Signed-off-by: Bartosz Golaszewski <bartekgola@gmail.com>

diff --git a/src/lib/core.c b/src/lib/core.c
index 9410601945ac74e356caf68f2a2c85842786a4ac..d285d9cf6827b2c9b5436e0da7e2abc4ec086a50 100644 (file)
--- a/src/lib/core.c
+++ b/src/lib/core.c
@@ -43,10 +43,8 @@ struct gpiod_line {
        struct gpiod_chip *chip;
        int fd;
 
-       char *name;
-       char *consumer;
-       char name_buf[32];
-       char consumer_buf[32];
+       char name[32];
+       char consumer[32];
 };
 
 struct gpiod_chip {
@@ -55,22 +53,10 @@ struct gpiod_chip {
 
        int fd;
 
-       char *name;
-       char *label;
-       char name_buf[32];
-       char label_buf[32];
+       char name[32];
+       char label[32];
 };
 
-static void strcpy_info(char *dst, const char *src, size_t sz, char **ptr)
-{
-       if (src[0] != '\0') {
-               strncpy(dst, src, sz);
-               *ptr = dst;
-       } else {
-               *ptr = NULL;
-       }
-}
-
 struct gpiod_chip * gpiod_chip_open(const char *path)
 {
        struct gpiochip_info info;
@@ -87,18 +73,29 @@ struct gpiod_chip * gpiod_chip_open(const char *path)
 
        memset(chip, 0, sizeof(*chip));
        memset(&info, 0, sizeof(info));
-       chip->fd = fd;
 
        status = ioctl(fd, GPIO_GET_CHIPINFO_IOCTL, &info);
        if (status < 0)
                goto err_free_chip;
 
+       chip->fd = fd;
        chip->num_lines = info.lines;
 
-       strcpy_info(chip->name_buf, info.name,
-                   sizeof(chip->name_buf), &chip->name);
-       strcpy_info(chip->label_buf, info.label,
-                   sizeof(chip->label_buf), &chip->label);
+       /*
+        * GPIO device must have a name - don't bother checking this field. In
+        * the worst case (would have to be a weird kernel bug) it'll be empty.
+        */
+       strncpy(chip->name, info.name, sizeof(chip->name));
+
+       /*
+        * The kernel sets the label of a GPIO device to "unknown" if it
+        * hasn't been defined in DT, board file etc. On the off-chance that
+        * we got an empty string, do the same.
+        */
+       if (info.label[0] == '\0')
+               strncpy(chip->label, "unknown", sizeof(chip->label));
+       else
+               strncpy(chip->label, info.label, sizeof(chip->label));
 
        return chip;
 
@@ -208,12 +205,12 @@ unsigned int gpiod_line_offset(struct gpiod_line *line)
 
 const char * gpiod_line_name(struct gpiod_line *line)
 {
-       return line->name;
+       return line->name[0] == '\0' ? NULL : line->name;
 }
 
 const char * gpiod_line_consumer(struct gpiod_line *line)
 {
-       return line->consumer;
+       return line->consumer[0] == '\0' ? NULL : line->consumer;
 }
 
 int gpiod_line_direction(struct gpiod_line *line)
@@ -258,11 +255,6 @@ int gpiod_line_update(struct gpiod_line *line)
        if (rv < 0)
                return -1;
 
-       strcpy_info(line->name_buf, info.name,
-                   sizeof(line->name_buf), &line->name);
-       strcpy_info(line->consumer_buf, info.consumer,
-                   sizeof(line->consumer_buf), &line->consumer);
-
        line->direction = info.flags & GPIOLINE_FLAG_IS_OUT
                                                ? GPIOD_LINE_DIRECTION_OUTPUT
                                                : GPIOD_LINE_DIRECTION_INPUT;
@@ -274,6 +266,9 @@ int gpiod_line_update(struct gpiod_line *line)
        line->open_drain = info.flags & GPIOLINE_FLAG_OPEN_DRAIN;
        line->open_source = info.flags & GPIOLINE_FLAG_OPEN_SOURCE;
 
+       strncpy(line->name, info.name, sizeof(line->name));
+       strncpy(line->consumer, info.consumer, sizeof(line->consumer));
+
        line->up_to_date = true;
 
        return 0;