[alsa-devel] [PATCH alsa-utils 2/4] Avoid pointer arithmetic on `void *`

[Michael Forney]

The pointer operand to the binary `+` operator must be to a complete
object type.

Signed-off-by: Michael Forney <mforney at mforney.org>
---
 aplay/aplay.c                     | 4 ++--
 axfer/xfer-libasound-irq-mmap.c   | 7 ++++---
 axfer/xfer-libasound-timer-mmap.c | 4 ++--
 bat/common.c                      | 2 +-
 seq/aplaymidi/aplaymidi.c         | 2 +-
 5 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/aplay/aplay.c b/aplay/aplay.c
index 908093c..08395f6 100644
--- a/aplay/aplay.c
+++ b/aplay/aplay.c
@@ -442,7 +442,7 @@ static ssize_t xwrite(int fd, const void *buf, size_t count)
 	size_t offset = 0;
 
 	while (offset < count) {
-		written = write(fd, buf + offset, count - offset);
+		written = write(fd, (char *)buf + offset, count - offset);
 		if (written <= 0)
 			return written;
 
@@ -1210,7 +1210,7 @@ static int test_au(int fd, void *buffer)
 	hwparams.channels = BE_INT(ap->channels);
 	if (hwparams.channels < 1 || hwparams.channels > 256)
 		return -1;
-	if ((size_t)safe_read(fd, buffer + sizeof(AuHeader), BE_INT(ap->hdr_size) - sizeof(AuHeader)) != BE_INT(ap->hdr_size) - sizeof(AuHeader)) {
+	if ((size_t)safe_read(fd, (char *)buffer + sizeof(AuHeader), BE_INT(ap->hdr_size) - sizeof(AuHeader)) != BE_INT(ap->hdr_size) - sizeof(AuHeader)) {
 		error(_("read error"));
 		prg_exit(EXIT_FAILURE);
 	}
diff --git a/axfer/xfer-libasound-irq-mmap.c b/axfer/xfer-libasound-irq-mmap.c
index a13b3c3..386e741 100644
--- a/axfer/xfer-libasound-irq-mmap.c
+++ b/axfer/xfer-libasound-irq-mmap.c
@@ -146,9 +146,10 @@ static int irq_mmap_process_frames(struct libasound_state *state,
 	// TODO: Perhaps, the complex layout can be supported as a variation of
 	// vector type. However, there's no driver with this layout.
 	if (layout->vector == NULL) {
-		frame_buf = areas[0].addr;
-		frame_buf += snd_pcm_frames_to_bytes(state->handle,
-						     frame_offset);
+		char *buf;
+		buf = areas[0].addr;
+		buf += snd_pcm_frames_to_bytes(state->handle, frame_offset);
+		frame_buf = buf;
 	} else {
 		int i;
 		for (i = 0; i < layout->samples_per_frame; ++i) {
diff --git a/axfer/xfer-libasound-timer-mmap.c b/axfer/xfer-libasound-timer-mmap.c
index 1c642fe..ba26e29 100644
--- a/axfer/xfer-libasound-timer-mmap.c
+++ b/axfer/xfer-libasound-timer-mmap.c
@@ -100,8 +100,8 @@ static void *get_buffer(struct libasound_state *state,
 
 	if (layout->vector == NULL) {
 		char *buf;
-		buf = areas[0].addr + snd_pcm_frames_to_bytes(state->handle,
-							      frame_offset);
+		buf = areas[0].addr;
+		buf += snd_pcm_frames_to_bytes(state->handle, frame_offset);
 		frame_buf = buf;
 	} else {
 		int i;
diff --git a/bat/common.c b/bat/common.c
index d3d1f28..339e749 100644
--- a/bat/common.c
+++ b/bat/common.c
@@ -231,7 +231,7 @@ int generate_input_data(struct bat *bat, void *buffer, int bytes, int frames)
 		load = 0;
 
 		while (1) {
-			err = fread(buffer + load, 1, bytes - load, bat->fp);
+			err = fread((char *)buffer + load, 1, bytes - load, bat->fp);
 			if (0 == err) {
 				if (feof(bat->fp)) {
 					fprintf(bat->log,
diff --git a/seq/aplaymidi/aplaymidi.c b/seq/aplaymidi/aplaymidi.c
index 12d6fac..b086e70 100644
--- a/seq/aplaymidi/aplaymidi.c
+++ b/seq/aplaymidi/aplaymidi.c
@@ -633,7 +633,7 @@ static void handle_big_sysex(snd_seq_event_t *ev)
 		check_snd("sync output", err);
 		if (sleep(1))
 			fatal("aborted");
-		ev->data.ext.ptr += MIDI_BYTES_PER_SEC;
+		ev->data.ext.ptr = (char *)ev->data.ext.ptr + MIDI_BYTES_PER_SEC;
 		length -= MIDI_BYTES_PER_SEC;
 	}
 	ev->data.ext.len = length;
-- 
2.25.0