[PATCH wayland 2/3] Add version information to wl_message signatures.

[Jason Ekstrand]

This commit adds version information to wl_message signatures and a
wl_message_get_since function to retrieve.  The since version comes in the
form of a (possible) integer at the begining of the message.  If the
message starts with an integer, then it specifies the "since" version of
that message.  Messages present in version one do not get this "since"
information.  In this way we can run-time detect the version information
for a structure on a per-message basis.

Signed-off-by: Jason Ekstrand <jason at jlekstrand.net>
---
 src/connection.c      | 55 ++++++++++++++++++++++++++++++++++++++++-----------
 src/scanner.c         |  4 ++++
 src/wayland-private.h |  3 +++
 3 files changed, 50 insertions(+), 12 deletions(-)

diff --git a/src/connection.c b/src/connection.c
index 95edd6e..2ca9bce 100644
--- a/src/connection.c
+++ b/src/connection.c
@@ -402,28 +402,59 @@ wl_connection_put_fd(struct wl_connection *connection, int32_t fd)
 const char *
 get_next_argument(const char *signature, struct argument_details *details)
 {
-	if (*signature == '?') {
-		details->nullable = 1;
-		signature++;
-	} else
-		details->nullable = 0;
-
-	details->type = *signature;
-	return signature + 1;
+	details->nullable = 0;
+	for(; *signature; ++signature) {
+		switch(*signature) {
+		case 'i':
+		case 'u':
+		case 'f':
+		case 's':
+		case 'o':
+		case 'n':
+		case 'a':
+		case 'h':
+			details->type = *signature;
+			return signature + 1;
+		case '?':
+			details->nullable = 1;
+		}
+	}
+	return signature;
 }
 
 int
 arg_count_for_signature(const char *signature)
 {
 	int count = 0;
-	while (*signature) {
-		if (*signature != '?')
-			count++;
-		signature++;
+	for(; *signature; ++signature) {
+		switch(*signature) {
+		case 'i':
+		case 'u':
+		case 'f':
+		case 's':
+		case 'o':
+		case 'n':
+		case 'a':
+		case 'h':
+			++count;
+		}
 	}
 	return count;
 }
 
+int
+wl_message_get_since(const struct wl_message *message)
+{
+	int since;
+
+	since = atoi(message->signature);
+
+	if (since == 0)
+		since = 1;
+
+	return since;
+}
+
 void
 wl_argument_from_va_list(const char *signature, union wl_argument *args,
 			 int count, va_list ap)
diff --git a/src/scanner.c b/src/scanner.c
index 6ed93f0..76feb36 100644
--- a/src/scanner.c
+++ b/src/scanner.c
@@ -1033,6 +1033,10 @@ emit_messages(struct wl_list *message_list,
 
 	wl_list_for_each(m, message_list, link) {
 		printf("\t{ \"%s\", \"", m->name);
+
+		if (m->since > 1)
+			printf("%d", m->since);
+
 		wl_list_for_each(a, &m->arg_list, link) {
 			if (is_nullable_type(a) && a->nullable)
 				printf("?");
diff --git a/src/wayland-private.h b/src/wayland-private.h
index eec7dff..1a97bf1 100644
--- a/src/wayland-private.h
+++ b/src/wayland-private.h
@@ -127,6 +127,9 @@ get_next_argument(const char *signature, struct argument_details *details);
 int
 arg_count_for_signature(const char *signature);
 
+int
+wl_message_get_since(const struct wl_message *message);
+
 void
 wl_argument_from_va_list(const char *signature, union wl_argument *args,
 			 int count, va_list ap);
-- 
1.8.2.1