[rfc] [7/7] Modernize AIX target: eliminate CHILD_SPECIAL_WAITSTATUS

["Ulrich Weigand" <uweigand at de dot ibm dot com>]

Hello,

this gets rid of the CHILD_SPECIAL_WAITSTATUS special hook by 
overriding the to_wait target method in rs6000-nat.c.

Tested on powerpc-ibm-aix5.3.0.0.

Bye,
Ulrich

ChangeLog:

	* config/rs6000/nm-rs6000.h (CHILD_SPECIAL_WAITSTATUS): Remove.
	* rs6000-nat.c (rs6000_wait): New function.
	(_initialize_core_rs6000): Install it as to_wait target method.
	* target.c (store_waitstatus): Don't check CHILD_SPECIAL_WAITSTATUS.


diff -urNp gdb-orig/gdb/config/rs6000/nm-rs6000.h gdb-head/gdb/config/rs6000/nm-rs6000.h
--- gdb-orig/gdb/config/rs6000/nm-rs6000.h	Tue Apr 24 15:07:18 2007
+++ gdb-head/gdb/config/rs6000/nm-rs6000.h	Tue Apr 24 15:28:07 2007
@@ -51,16 +51,3 @@ extern char *xcoff_solib_address (CORE_A
 /* Flag for machine-specific stuff in shared files.  FIXME */
 #define DEPRECATED_IBM6000_TARGET
 
-/* AIX has a couple of strange returns from wait().  */
-
-#define CHILD_SPECIAL_WAITSTATUS(ourstatus, hoststatus) ( \
-  /* "stop after load" status.  */ \
-  (hoststatus) == 0x57c ? (ourstatus)->kind = TARGET_WAITKIND_LOADED, 1 : \
-  \
-  /* signal 0. I have no idea why wait(2) returns with this status word.  */ \
-  /* It looks harmless. */ \
-  (hoststatus) == 0x7f ? (ourstatus)->kind = TARGET_WAITKIND_SPURIOUS, 1 : \
-  \
-  /* A normal waitstatus.  Let the usual macros deal with it.  */ \
-  0)
-
diff -urNp gdb-orig/gdb/rs6000-nat.c gdb-head/gdb/rs6000-nat.c
--- gdb-orig/gdb/rs6000-nat.c	Tue Apr 24 15:07:18 2007
+++ gdb-head/gdb/rs6000-nat.c	Tue Apr 24 15:27:58 2007
@@ -520,6 +520,63 @@ rs6000_xfer_partial (struct target_ops *
     }
 }
 
+/* Wait for the child specified by PTID to do something.  Return the
+   process ID of the child, or MINUS_ONE_PTID in case of error; store
+   the status in *OURSTATUS.  */
+
+static ptid_t
+rs6000_wait (ptid_t ptid, struct target_waitstatus *ourstatus)
+{
+  pid_t pid;
+  int status, save_errno;
+
+  do
+    {
+      set_sigint_trap ();
+      set_sigio_trap ();
+
+      do
+	{
+	  pid = waitpid (ptid_get_pid (ptid), &status, 0);
+	  save_errno = errno;
+	}
+      while (pid == -1 && errno == EINTR);
+
+      clear_sigio_trap ();
+      clear_sigint_trap ();
+
+      if (pid == -1)
+	{
+	  fprintf_unfiltered (gdb_stderr,
+			      _("Child process unexpectedly missing: %s.\n"),
+			      safe_strerror (save_errno));
+
+	  /* Claim it exited with unknown signal.  */
+	  ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
+	  ourstatus->value.sig = TARGET_SIGNAL_UNKNOWN;
+	  return minus_one_ptid;
+	}
+
+      /* Ignore terminated detached child processes.  */
+      if (!WIFSTOPPED (status) && pid != ptid_get_pid (inferior_ptid))
+	pid = -1;
+    }
+  while (pid == -1);
+
+  /* AIX has a couple of strange returns from wait().  */
+
+  /* stop after load" status.  */
+  if (status == 0x57c)
+    ourstatus->kind = TARGET_WAITKIND_LOADED;
+  /* signal 0. I have no idea why wait(2) returns with this status word.  */
+  else if (status == 0x7f)
+    ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
+  /* A normal waitstatus.  Let the usual macros deal with it.  */
+  else
+    store_waitstatus (ourstatus, status);
+
+  return pid_to_ptid (pid);
+}
 
 /* Execute one dummy breakpoint instruction.  This way we give the kernel
    a chance to do some housekeeping and update inferior's internal data,
@@ -1254,6 +1311,8 @@ _initialize_core_rs6000 (void)
 
   super_create_inferior = t->to_create_inferior;
   t->to_create_inferior = rs6000_create_inferior;
+
+  t->to_wait = rs6000_wait;
 
   add_target (t);
 
diff -urNp gdb-orig/gdb/target.c gdb-head/gdb/target.c
--- gdb-orig/gdb/target.c	Wed Apr 18 16:17:21 2007
+++ gdb-head/gdb/target.c	Tue Apr 24 15:28:54 2007
@@ -1976,13 +1976,6 @@ generic_mourn_inferior (void)
 void
 store_waitstatus (struct target_waitstatus *ourstatus, int hoststatus)
 {
-#ifdef CHILD_SPECIAL_WAITSTATUS
-  /* CHILD_SPECIAL_WAITSTATUS should return nonzero and set *OURSTATUS
-     if it wants to deal with hoststatus.  */
-  if (CHILD_SPECIAL_WAITSTATUS (ourstatus, hoststatus))
-    return;
-#endif
-
   if (WIFEXITED (hoststatus))
     {
       ourstatus->kind = TARGET_WAITKIND_EXITED;
-- 
  Dr. Ulrich Weigand
  GNU Toolchain for Linux on System z and Cell BE
  Ulrich.Weigand@de.ibm.com