[PATCH v1] Add compatibility check for idtype_t

[David Wei <dw@davidwei.uk>]

io_uring_prep_waitid() requires idtype_t, which is not always defined on
all platforms.

Add a check for the presence of idtype_t during configure, and if not
found then add a definition in compat.h.

Signed-off-by: David Wei <dw@davidwei.uk>
---
 configure | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/configure b/configure
index 9d29e20..052920d 100755
--- a/configure
+++ b/configure
@@ -414,6 +414,22 @@ if compile_prog "" "" "futexv"; then
 fi
 print_config "futex waitv support" "$futexv"
 
+##########################################
+# Check idtype_t support
+has_idtype_t="no"
+cat > $TMPC << EOF
+#include <sys/wait.h>
+int main(void)
+{
+  idtype_t v;
+  return 0;
+}
+EOF
+if compile_prog "" "" "idtype_t"; then
+  has_idtype_t="yes"
+fi
+print_config "has_idtype_t" "$has_idtype_t"
+
 #############################################################################
 liburing_nolibc="no"
 if test "$use_libc" != "yes"; then
@@ -590,6 +606,17 @@ struct futex_waitv {
 	uint32_t	__reserved;
 };
 
+EOF
+fi
+
+if test "$has_idtype_t" != "yes"; then
+cat >> $compat_h << EOF
+typedef enum
+{
+  P_ALL,		/* Wait for any child.  */
+  P_PID,		/* Wait for specified process.  */
+  P_PGID		/* Wait for members of process group.  */
+} idtype_t;
 EOF
 fi
 cat >> $compat_h << EOF
-- 
2.39.3