Re: [PATCH v5 5/6] hppa: Add emulation of Artist graphics

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

Hi Sven,

On 12/20/19 10:15 PM, Sven Schnelle wrote:
> This adds emulation of Artist graphics good enough
> to get a Text console on both Linux and HP-UX. The
> X11 server from HP-UX also works.
> 
> Signed-off-by: Sven Schnelle <svens@stackframe.org>
> ---
>   hw/display/Kconfig       |    4 +
>   hw/display/Makefile.objs |    1 +
>   hw/display/artist.c      | 1450 ++++++++++++++++++++++++++++++++++++++
>   hw/display/trace-events  |    9 +
>   hw/hppa/Kconfig          |    1 +
>   hw/hppa/hppa_hardware.h  |    1 +
>   hw/hppa/machine.c        |    9 +
>   7 files changed, 1475 insertions(+)
>   create mode 100644 hw/display/artist.c
> 
> diff --git a/hw/display/Kconfig b/hw/display/Kconfig
> index c500d1fc6d..15d59e10dc 100644
> --- a/hw/display/Kconfig
> +++ b/hw/display/Kconfig
> @@ -91,6 +91,10 @@ config TCX
>   config CG3
>       bool
>   
> +config ARTIST
> +    bool
> +    select FRAMEBUFFER
> +
>   config VGA
>       bool
>   
> diff --git a/hw/display/Makefile.objs b/hw/display/Makefile.objs
> index f2182e3bef..5f03dfdcc4 100644
> --- a/hw/display/Makefile.objs
> +++ b/hw/display/Makefile.objs
> @@ -40,6 +40,7 @@ common-obj-$(CONFIG_SM501) += sm501.o
>   common-obj-$(CONFIG_TCX) += tcx.o
>   common-obj-$(CONFIG_CG3) += cg3.o
>   common-obj-$(CONFIG_NEXTCUBE) += next-fb.o
> +common-obj-$(CONFIG_ARTIST) += artist.o
>   
>   obj-$(CONFIG_VGA) += vga.o
>   
> diff --git a/hw/display/artist.c b/hw/display/artist.c
[...]
> +static void draw_line_size(ARTISTState *s, bool update_start)
> +{
> +
> +    int startx = artist_get_x(s->vram_start);
> +    int starty = artist_get_y(s->vram_start);
> +    int endx = artist_get_x(s->line_size);
> +    int endy = artist_get_y(s->line_size);
> +
> +    trace_artist_draw_line(startx, starty, endx, endy);
> +    draw_line(s, startx, starty, endx, endy, update_start, -1, -1);
> +}
> +
> +static void draw_line_xy(ARTISTState *s, bool update_start)
> +{
> +
> +    int startx = artist_get_x(s->vram_start);
> +    int starty = artist_get_y(s->vram_start);
> +    int sizex = artist_get_x(s->blockmove_size);
> +    int sizey = artist_get_y(s->blockmove_size);
> +    int linexy = s->line_xy >> 16;
> +    int endx, endy;
> +
> +    endx = startx;
> +    endy = starty;
> +
> +    if (sizex > 0) {
> +        endx = startx + linexy;
> +    }
> +
> +    if (sizex < 0) {
> +        endx = startx;
> +        startx -= linexy;
> +    }
> +
> +    if (sizey > 0) {
> +        endy = starty + linexy;
> +    }
> +
> +    if (sizey < 0) {
> +        endy = starty;
> +        starty -= linexy;
> +    }
> +
> +    if (startx < 0) {
> +        startx = 0;
> +    }
> +
> +    if (endx < 0) {
> +        endx = 0;

If negative, set to zero.

> +    }
> +
> +    if (starty < 0) {
> +        starty = 0;
> +    }
> +
> +    if (endy < 0) {
> +        endy = 0;

Ditto.

> +    }
> +
> +
> +    if (endx < 0) {
> +        return;

Here Coverity points:

 >>>     CID 1419388:  Control flow issues  (DEADCODE)
 >>>     Execution cannot reach this statement: "return;".

> +    }
> +
> +    if (endy < 0) {
> +        return;

Here again.

> +    }
> +
> +    trace_artist_draw_line(startx, starty, endx, endy);
> +    draw_line(s, startx, starty, endx, endy, false, -1, -1);
> +}
> +
> +static void draw_line_end(ARTISTState *s, bool update_start)
> +{
> +
> +    int startx = artist_get_x(s->vram_start);
> +    int starty = artist_get_y(s->vram_start);
> +    int endx = artist_get_x(s->line_end);
> +    int endy = artist_get_y(s->line_end);
> +
> +    trace_artist_draw_line(startx, starty, endx, endy);
> +    draw_line(s, startx, starty, endx, endy, update_start, -1, -1);
> +}