On Wed, 3 Sep 2014 19:44:04 +0200
"Nils Chr. Brause" <nilschrbra...@gmail.com> wrote:
> This replaces "[PATCH wayland] Add "enum" attribute to "arg" elements".
> Previous concers have be incorporated and it is meant for 1.7.
>
> From 733fb18b163de93276f092a4be100c7e0c0c723f Mon Sep 17 00:00:00 2001
> From: "Nils Chr. Brause" <nilschrbra...@googlemail.com>
> Date: Wed, 3 Sep 2014 19:18:28 +0200
> Subject: [PATCH] wayland.xml: add "enum", "bitfield" and "is_bitfield"
> attributes
>
> There are programming languages, that are more strongly typed than
> C. People creating Wayland bindings for these languages will want to
> make use of this strong type system by declaring each enumeration a
> distinct type and differentiating between enumerations and bit fields.
>
> For code generation to work with these languages, there needs to be
> information about which enumerations are actually bit fields and which
> enumerations or bit fields may be passed/received in which
> request/event arguments.
>
> This is accomplished by adding an "is_bitfield" attribute to "enum"
> elements, which are actually bitfields and by adding "enum" or
> "bitfield" attributes to the "arg" elements of requests and
> events. The values of the "enum" and "bitfield" attributes have the
> format "$interface.$name", where "$interface" is the name of the
> interface, where the enumeration or bit field is declared and "$name"
> is the name of the enumeration or bit field, which is used in this
> argument.
>
> The scanner has been modified to enforce those rules.
> ---
> protocol/wayland.dtd | 3 ++
> protocol/wayland.xml | 42 ++++++++++-----------
> src/scanner.c | 101
> ++++++++++++++++++++++++++++++++++++++++++++++++++-
> 3 files changed, 124 insertions(+), 22 deletions(-)
>
> diff --git a/protocol/wayland.dtd b/protocol/wayland.dtd
> index b8b1573..4506201 100644
> --- a/protocol/wayland.dtd
> +++ b/protocol/wayland.dtd
> @@ -14,6 +14,7 @@
> <!ELEMENT enum (description?,entry*)>
> <!ATTLIST enum name CDATA #REQUIRED>
> <!ATTLIST enum since CDATA #IMPLIED>
> + <!ATTLIST enum is_bitfield CDATA #IMPLIED>
> <!ELEMENT entry (description?)>
> <!ATTLIST entry name CDATA #REQUIRED>
> <!ATTLIST entry value CDATA #REQUIRED>
> @@ -25,5 +26,7 @@
> <!ATTLIST arg summary CDATA #IMPLIED>
> <!ATTLIST arg interface CDATA #IMPLIED>
> <!ATTLIST arg allow-null CDATA #IMPLIED>
> + <!ATTLIST arg enum CDATA #IMPLIED>
> + <!ATTLIST arg bitfield CDATA #IMPLIED>
> <!ELEMENT description (#PCDATA)>
> <!ATTLIST description summary CDATA #REQUIRED>
> diff --git a/protocol/wayland.xml b/protocol/wayland.xml
> index bb457bc..878c347 100644
> --- a/protocol/wayland.xml
> +++ b/protocol/wayland.xml
> @@ -229,7 +229,7 @@
> <arg name="width" type="int"/>
> <arg name="height" type="int"/>
> <arg name="stride" type="int"/>
> - <arg name="format" type="uint"/>
> + <arg name="format" type="uint" enum="wl_shm.format"/>
> </request>
>
> <request name="destroy" type="destructor">
> @@ -367,7 +367,7 @@
> can be used for buffers. Known formats include
> argb8888 and xrgb8888.
> </description>
> - <arg name="format" type="uint"/>
> + <arg name="format" type="uint" enum="wl_shm.format"/>
> </event>
> </interface>
>
> @@ -723,7 +723,7 @@
> <arg name="serial" type="uint" summary="serial of the implicit grab on
> the pointer"/>
> </request>
>
> - <enum name="resize">
> + <enum name="resize" is_bitfield="true">
> <description summary="edge values for resizing">
> These values are used to indicate which edge of a surface
> is being dragged in a resize operation. The server may
> @@ -751,7 +751,7 @@
> </description>
> <arg name="seat" type="object" interface="wl_seat" summary="the
> wl_seat whose pointer is used"/>
> <arg name="serial" type="uint" summary="serial of the implicit grab on
> the pointer"/>
> - <arg name="edges" type="uint" summary="which edge or corner is being
> dragged"/>
> + <arg name="edges" type="uint" summary="which edge or corner is being
> dragged" bitfield="wl_shell_surface.resize"/>
> </request>
>
> <request name="set_toplevel">
> @@ -762,7 +762,7 @@
> </description>
> </request>
>
> - <enum name="transient">
> + <enum name="transient" is_bitfield="true">
> <description summary="details of transient behaviour">
> These flags specify details of the expected behaviour
> of transient surfaces. Used in the set_transient request.
> @@ -784,7 +784,7 @@
> <arg name="parent" type="object" interface="wl_surface"/>
> <arg name="x" type="int"/>
> <arg name="y" type="int"/>
> - <arg name="flags" type="uint"/>
> + <arg name="flags" type="uint" bitfield="wl_shell_surface.transient"/>
> </request>
>
> <enum name="fullscreen_method">
> @@ -835,7 +835,7 @@
> with the dimensions for the output on which the surface will
> be made fullscreen.
> </description>
> - <arg name="method" type="uint"/>
> + <arg name="method" type="uint"
> enum="wl_shell_surface.fullscreen_method"/>
> <arg name="framerate" type="uint"/>
> <arg name="output" type="object" interface="wl_output"
> allow-null="true"/>
> </request>
> @@ -868,7 +868,7 @@
> <arg name="parent" type="object" interface="wl_surface"/>
> <arg name="x" type="int"/>
> <arg name="y" type="int"/>
> - <arg name="flags" type="uint"/>
> + <arg name="flags" type="uint" bitfield="wl_shell_surface.transient"/>
> </request>
>
> <request name="set_maximized">
> @@ -949,7 +949,7 @@
> in surface local coordinates.
> </description>
>
> - <arg name="edges" type="uint"/>
> + <arg name="edges" type="uint" bitfield="wl_shell_surface.resize"/>
> <arg name="width" type="int"/>
> <arg name="height" type="int"/>
> </event>
> @@ -1242,7 +1242,7 @@
> wl_output.transform enum the invalid_transform protocol error
> is raised.
> </description>
> - <arg name="transform" type="int"/>
> + <arg name="transform" type="int" bitfield="wl_output.transform"/>
> </request>
>
> <!-- Version 3 additions -->
> @@ -1285,7 +1285,7 @@
> maintains a keyboard focus and a pointer focus.
> </description>
>
> - <enum name="capability">
> + <enum name="capability" is_bitfield="true">
> <description summary="seat capability bitmask">
> This is a bitmask of capabilities this seat has; if a member is
> set, then it is present on the seat.
> @@ -1301,7 +1301,7 @@
> keyboard or touch capabilities. The argument is a capability
> enum containing the complete set of capabilities this seat has.
> </description>
> - <arg name="capabilities" type="uint"/>
> + <arg name="capabilities" type="uint" bitfield="wl_seat.capability"/>
> </event>
>
> <request name="get_pointer">
> @@ -1461,7 +1461,7 @@
> <arg name="serial" type="uint"/>
> <arg name="time" type="uint" summary="timestamp with millisecond
> granularity"/>
> <arg name="button" type="uint"/>
> - <arg name="state" type="uint"/>
> + <arg name="state" type="uint" enum="wl_pointer.button_state"/>
> </event>
>
> <enum name="axis">
> @@ -1493,7 +1493,7 @@
> </description>
>
> <arg name="time" type="uint" summary="timestamp with millisecond
> granularity"/>
> - <arg name="axis" type="uint"/>
> + <arg name="axis" type="uint" enum="wl_pointer.axis"/>
> <arg name="value" type="fixed"/>
> </event>
>
> @@ -1527,7 +1527,7 @@
> This event provides a file descriptor to the client which can be
> memory-mapped to provide a keyboard mapping description.
> </description>
> - <arg name="format" type="uint"/>
> + <arg name="format" type="uint" enum="wl_keyboard.keymap_format"/>
> <arg name="fd" type="fd"/>
> <arg name="size" type="uint"/>
> </event>
> @@ -1572,7 +1572,7 @@
> <arg name="serial" type="uint"/>
> <arg name="time" type="uint" summary="timestamp with millisecond
> granularity"/>
> <arg name="key" type="uint"/>
> - <arg name="state" type="uint"/>
> + <arg name="state" type="uint" enum="wl_keyboard.key_state"/>
> </event>
>
> <event name="modifiers">
> @@ -1714,7 +1714,7 @@
> <entry name="vertical_bgr" value="5"/>
> </enum>
>
> - <enum name="transform">
> + <enum name="transform" is_bitfield="true">
> <description summary="transform from framebuffer to output">
> This describes the transform that a compositor will apply to a
> surface to compensate for the rotation or mirroring of an
> @@ -1753,17 +1753,17 @@
> summary="width in millimeters of the output"/>
> <arg name="physical_height" type="int"
> summary="height in millimeters of the output"/>
> - <arg name="subpixel" type="int"
> + <arg name="subpixel" type="int" enum="wl_output.subpixel"
> summary="subpixel orientation of the output"/>
> <arg name="make" type="string"
> summary="textual description of the manufacturer"/>
> <arg name="model" type="string"
> summary="textual description of the model"/>
> - <arg name="transform" type="int"
> + <arg name="transform" type="int" bitfield="wl_output.transform"
> summary="transform that maps framebuffer to output"/>
> </event>
>
> - <enum name="mode">
> + <enum name="mode" is_bitfield="true">
> <description summary="mode information">
> These flags describe properties of an output mode.
> They are used in the flags bitfield of the mode event.
> @@ -1790,7 +1790,7 @@
> the output may be scaled, as described in wl_output.scale,
> or transformed , as described in wl_output.transform.
> </description>
> - <arg name="flags" type="uint" summary="bitfield of mode flags"/>
> + <arg name="flags" type="uint" summary="bitfield of mode flags"
> bitfield="wl_output.mode"/>
> <arg name="width" type="int" summary="width of the mode in hardware
> units"/>
> <arg name="height" type="int" summary="height of the mode in hardware
> units"/>
> <arg name="refresh" type="int" summary="vertical refresh rate in mHz"/>
> diff --git a/src/scanner.c b/src/scanner.c
> index 72fd3e8..b240790 100644
> --- a/src/scanner.c
> +++ b/src/scanner.c
> @@ -112,6 +112,8 @@ struct arg {
> enum arg_type type;
> int nullable;
> char *interface_name;
> + char *enum_name;
> + char *bitfield_name;
> struct wl_list link;
> char *summary;
> };
> @@ -119,6 +121,7 @@ struct arg {
> struct enumeration {
> char *name;
> char *uppercase_name;
> + int is_bitfield;
> struct wl_list entry_list;
> struct wl_list link;
> struct description *description;
> @@ -314,7 +317,7 @@ start_element(void *data, const char *element_name, const
> char **atts)
> struct entry *entry;
> struct description *description;
> const char *name, *type, *interface_name, *value, *summary, *since;
> - const char *allow_null;
> + const char *allow_null, *enum_name, *bitfield_name, *is_bitfield;
> char *end;
> int i, version;
>
> @@ -323,11 +326,14 @@ start_element(void *data, const char *element_name,
> const char **atts)
> type = NULL;
> version = 0;
> interface_name = NULL;
> + enum_name = NULL;
> + bitfield_name = NULL;
> value = NULL;
> summary = NULL;
> description = NULL;
> since = NULL;
> allow_null = NULL;
> + is_bitfield = NULL;
> for (i = 0; atts[i]; i += 2) {
> if (strcmp(atts[i], "name") == 0)
> name = atts[i + 1];
> @@ -339,12 +345,18 @@ start_element(void *data, const char *element_name,
> const char **atts)
> value = atts[i + 1];
> if (strcmp(atts[i], "interface") == 0)
> interface_name = atts[i + 1];
> + if (strcmp(atts[i], "enum") == 0)
> + enum_name = atts[i + 1];
> + if (strcmp(atts[i], "bitfield") == 0)
> + bitfield_name = atts[i + 1];
> if (strcmp(atts[i], "summary") == 0)
> summary = atts[i + 1];
> if (strcmp(atts[i], "since") == 0)
> since = atts[i + 1];
> if (strcmp(atts[i], "allow-null") == 0)
> allow_null = atts[i + 1];
> + if (strcmp(atts[i], "is_bitfield") == 0)
> + is_bitfield = atts[i + 1];
> }
>
> ctx->character_data_length = 0;
> @@ -461,9 +473,31 @@ start_element(void *data, const char *element_name,
> const char **atts)
> else
> arg->interface_name = NULL;
> break;
> + case UNSIGNED:
> + case INT:
> + if (enum_name) {
> + arg->enum_name = xstrdup(enum_name);
> + arg->bitfield_name = NULL;
> + }
> + else if (bitfield_name) {
> + arg->bitfield_name = xstrdup(bitfield_name);
> + arg->enum_name = NULL;
> + }
> + else {
> + arg->bitfield_name = NULL;
> + arg->enum_name = NULL;
> + }
> +
> + if (enum_name && bitfield_name)
> + fail(&ctx->loc, "bitfield and enum attribute
> cannot both be set");
> + break;
> default:
> if (interface_name != NULL)
> fail(&ctx->loc, "interface attribute not
> allowed for type %s", type);
> + if (enum_name != NULL)
> + fail(&ctx->loc, "enum attribute not allowed for
> type %s", type);
> + if (bitfield_name != NULL)
> + fail(&ctx->loc, "bitfield attribute not allowed
> for type %s", type);
This looks broken.
What if
- int or unsigned has "interface" attribute? It should be an error.
- new_id or object has "enum" or "bitfield" attribute? Should be an
error.
You probably want your own switch-clause.
> break;
> }
>
> @@ -497,6 +531,13 @@ start_element(void *data, const char *element_name,
> const char **atts)
> &enumeration->link);
>
> ctx->enumeration = enumeration;
> +
> + if (is_bitfield == NULL || strcmp(is_bitfield, "false") == 0)
> + enumeration->is_bitfield = 0;
> + else if (strcmp(is_bitfield, "true") == 0)
> + enumeration->is_bitfield = 1;
> + else
> + fail(&ctx->loc, "invalid value for is_bitfield
> attribute (%s)", is_bitfield);
> } else if (strcmp(element_name, "entry") == 0) {
> if (name == NULL)
> fail(&ctx->loc, "no entry name given");
> @@ -1246,6 +1287,60 @@ emit_code(struct protocol *protocol)
> }
> }
>
> +static int
> +enum_exists(struct protocol *protocol, const char *enum_name, int
> is_bitfield)
> +{
> + struct interface *i;
> + struct enumeration *e;
> + char full_name[64];
> +
> + wl_list_for_each(i, &protocol->interface_list, link) {
> + wl_list_for_each(e, &i->enumeration_list, link) {
> + sprintf(full_name, "%s.%s", i->name, e->name);
Use snprintf to avoid buffer overflows.
Or split enum_name, and match both halves separately.
> + if (strcmp(full_name, enum_name) == 0 &&
> + e->is_bitfield == is_bitfield)
> + return 1;
> + }
> + }
> + return 0;
> +}
> +
> +static void
> +check_message(struct protocol *protocol, struct message *m)
> +{
> + struct arg *a;
> +
> + wl_list_for_each(a, &m->arg_list, link)
> + if ((a->type == UNSIGNED || a->type == INT)) {
> + if (a->enum_name != NULL &&
> + !enum_exists(protocol, a->enum_name, 0)) {
> + fprintf(stderr, "enum %s does not exist\n",
> + a->enum_name);
> + exit(EXIT_FAILURE);
> + }
> + else if (a->bitfield_name != NULL &&
> + !enum_exists(protocol, a->bitfield_name, 1)) {
> + fprintf(stderr, "bitfield %s does not exist\n",
> + a->enum_name);
> + exit(EXIT_FAILURE);
> + }
> + }
> +}
> +
> +static void
> +check_protocol(struct protocol *protocol)
> +{
> + struct interface *i;
> + struct message *m;
> +
> + wl_list_for_each(i, &protocol->interface_list, link) {
> + wl_list_for_each(m, &i->request_list, link)
> + check_message(protocol, m);
> + wl_list_for_each(m, &i->event_list, link)
> + check_message(protocol, m);
> + }
> +}
> +
> int main(int argc, char *argv[])
> {
> struct parse_context ctx;
> @@ -1302,6 +1397,10 @@ int main(int argc, char *argv[])
>
> XML_ParserFree(ctx.parser);
>
> + /* some checks can only be performed after *
> + * the whole protocol has been read in */
> + check_protocol(&protocol);
> +
> switch (mode) {
> case CLIENT_HEADER:
> emit_header(&protocol, CLIENT);
Should we also enforce, that only UNSIGNED is valid for bitfields?
So, what do other people think of the idea in this patch?
I want to see some other Wayland developers support this, as I am not
confident with my own judgement here.
Thanks,
pq
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