[Spice-devel] [PATCH spice-server 09/10] Avoid some alignment warnings using clang

[Victor Toso]

Hi,

On Mon, Jan 22, 2018 at 05:55:01PM +0000, Frediano Ziglio wrote:
> clang reports may warnings like:
> 
> test-display-base.c:252:11: error: cast from 'uint8_t *' (aka 'unsigned char *') to 'uint32_t *' (aka 'unsigned int *') increases required alignment from 1 to 4 [-Werror,-Wcast-align]
>     dst = (uint32_t *)bitmap;
>           ^~~~~~~~~~~~~~~~~~
> 
> Use SPICE_ALIGNED_CAST/SPICE_UNALIGNED_CAST macros in common/mem.h to
> mark the cast safe or possibly unsafe.
> 
> Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
Acked-by: Victor Toso <victortoso at redhat.com>
> ---
>  server/lz4-encoder.c                  |  3 ++-
>  server/tests/test-display-base.c      |  2 +-
>  server/tests/test-display-streaming.c | 10 ++++++----
>  server/tests/test-gst.c               |  4 ++--
>  4 files changed, 11 insertions(+), 8 deletions(-)
> 
> diff --git a/server/lz4-encoder.c b/server/lz4-encoder.c
> index a8f0d17c..8657e8d9 100644
> --- a/server/lz4-encoder.c
> +++ b/server/lz4-encoder.c
> @@ -89,7 +89,8 @@ int lz4_encode(Lz4EncoderContext *lz4, int height, int stride, uint8_t *io_ptr,
>              LZ4_freeStream(stream);
>              return 0;
>          }
> -        *((uint32_t *)compressed_lines) = GUINT32_TO_BE(enc_size);
> +        // compressed_lines is returned by malloc so is surely aligned
> +        *SPICE_ALIGNED_CAST(uint32_t *, compressed_lines) = GUINT32_TO_BE(enc_size);
>  
>          out_size += enc_size += 4;
>          already_copied = 0;
> diff --git a/server/tests/test-display-base.c b/server/tests/test-display-base.c
> index a86a8b67..ea3a23ba 100644
> --- a/server/tests/test-display-base.c
> +++ b/server/tests/test-display-base.c
> @@ -249,7 +249,7 @@ static SimpleSpiceUpdate *test_spice_create_update_solid(uint32_t surface_id, QX
>      bh = bbox.bottom - bbox.top;
>  
>      bitmap = g_malloc(bw * bh * 4);
> -    dst = (uint32_t *)bitmap;
> +    dst = SPICE_ALIGNED_CAST(uint32_t *, bitmap);
>  
>      for (i = 0 ; i < bh * bw ; ++i, ++dst) {
>          *dst = color;
> diff --git a/server/tests/test-display-streaming.c b/server/tests/test-display-streaming.c
> index 1cd3f6e5..6ab70db9 100644
> --- a/server/tests/test-display-streaming.c
> +++ b/server/tests/test-display-streaming.c
> @@ -32,6 +32,8 @@
>  
>  #include <glib.h>
>  
> +#include <common/mem.h>
> +
>  #include "test-display-base.h"
>  
>  static int sized;
> @@ -51,7 +53,7 @@ static void create_overlay(Command *command , int width, int height)
>  
>      cmd->num_clip_rects = 0;
>      cmd->bitmap = g_malloc(width * height * 4 );
> -    dst = (uint32_t *)cmd->bitmap;
> +    dst = SPICE_ALIGNED_CAST(uint32_t *, cmd->bitmap);
>      for (int i = 0; i < width * height; i++, dst++) {
>          *dst = 0x8B008B;
>      }
> @@ -123,7 +125,7 @@ static void create_clipped_frame(Test *test, Command *command, int clipping_fact
>  
>      cmd->bitmap = g_malloc(width*height*4);
>      memset(cmd->bitmap, 0xff, width*height*4);
> -    dst = (uint32_t *)(cmd->bitmap + cur_line*width*4);
> +    dst = SPICE_ALIGNED_CAST(uint32_t *, cmd->bitmap + cur_line*width*4);
>      for (; cur_line < end_line; cur_line++) {
>          int col;
>          for (col = 0; col < width; col++, dst++) {
> @@ -134,13 +136,13 @@ static void create_clipped_frame(Test *test, Command *command, int clipping_fact
>          int i;
>          uint32_t color = 0xffffff & rand();
>  
> -        dst = (uint32_t *)cmd->bitmap;
> +        dst = SPICE_ALIGNED_CAST(uint32_t *, cmd->bitmap);
>  
>          for (i = 0; i < 50*width; i++, dst++) {
>              *dst = color;
>          }
>  
> -        dst = ((uint32_t *)(cmd->bitmap + (height - 50)*4*width));
> +        dst = SPICE_ALIGNED_CAST(uint32_t *, cmd->bitmap + (height - 50)*4*width);
>  
>          for (i = 0; i < 50*width; i++, dst++) {
>              *dst = color;
> diff --git a/server/tests/test-gst.c b/server/tests/test-gst.c
> index 91ef92d6..43ee4004 100644
> --- a/server/tests/test-gst.c
> +++ b/server/tests/test-gst.c
> @@ -905,7 +905,7 @@ get_convert_line(SpiceBitmapFmt format)
>  static void
>  convert_line16(uint8_t *dest, const uint8_t *src, uint32_t width)
>  {
> -    uint16_t *dest16 = (uint16_t *) dest;
> +    uint16_t *dest16 = SPICE_ALIGNED_CAST(uint16_t *, dest);
>      for (; width; --width) {
>          *dest16++ = (src[0] >> 3) | ((src[1] & 0xf8) << 2) | ((src[2] & 0xf8) << 7);
>          src += 4;
> @@ -1055,7 +1055,7 @@ bitmap_extract32(SpiceBitmap *bitmap, uint8_t *buf, int32_t x, int32_t y, int32_
>  static uint8_t *
>  bitmap_extract16(SpiceBitmap *bitmap, uint8_t *buf, int32_t x, int32_t y, int32_t w)
>  {
> -    const uint16_t *line = (const uint16_t *)(bitmap_get_line(bitmap, y) + x * 2);
> +    const uint16_t *line = SPICE_ALIGNED_CAST(const uint16_t *, bitmap_get_line(bitmap, y) + x * 2);
>      uint8_t *dest = buf;
>      for (; w; --w) {
>          uint16_t pixel = *line++;
> -- 
> 2.14.3
> 
> _______________________________________________
> Spice-devel mailing list
> Spice-devel at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/spice-devel
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