follow-fork: don't lose the ptids as set by the target

This Linuxism has made its way into infrun.c, in the follow-fork code:

       inferior_ptid = ptid_build (child_pid, child_pid, 0);

The OS-specific code should fill in the LWPID, TID parts with the
appropriate values, if any, and the core code should not be peeking at
the components of the ptids.

gdb/
2015-03-04  Pedro Alves  <palves@redhat.com>

	* infrun.c (follow_fork_inferior): Use the whole of the
	inferior_ptid and pending_follow.related_pid ptids instead of
	building ptids from the process components.  Adjust verbose output
	to use target_pid_to_str.
	* linux-nat.c (linux_child_follow_fork): Use the whole of the
	inferior_ptid and pending_follow.related_pid ptids instead of
	building ptids from the process components.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 621b73f..6ed6f4a 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,13 @@
+2015-03-04  Pedro Alves  <palves@redhat.com>
+
+       * infrun.c (follow_fork_inferior): Use the whole of the
+       inferior_ptid and pending_follow.related_pid ptids instead of
+       building ptids from the process components.  Adjust verbose output
+       to use target_pid_to_str.
+       * linux-nat.c (linux_child_follow_fork): Use the whole of the
+       inferior_ptid and pending_follow.related_pid ptids instead of
+       building ptids from the process components.
+
 2015-03-04  Mark Kettenis  <kettenis@gnu.org>
 
        * inf-ptrace.c [PT_GET_PROCESS_STATE]

diff --git a/gdb/infrun.c b/gdb/infrun.c
index f87ed4c..abfeeee 100644 (file)
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -408,15 +408,12 @@ static int
 follow_fork_inferior (int follow_child, int detach_fork)
 {
   int has_vforked;
-  int parent_pid, child_pid;
+  ptid_t parent_ptid, child_ptid;
 
   has_vforked = (inferior_thread ()->pending_follow.kind
                 == TARGET_WAITKIND_VFORKED);
-  parent_pid = ptid_get_lwp (inferior_ptid);
-  if (parent_pid == 0)
-    parent_pid = ptid_get_pid (inferior_ptid);
-  child_pid
-    = ptid_get_pid (inferior_thread ()->pending_follow.value.related_pid);
+  parent_ptid = inferior_ptid;
+  child_ptid = inferior_thread ()->pending_follow.value.related_pid;
 
   if (has_vforked
       && !non_stop /* Non-stop always resumes both branches.  */
@@ -460,10 +457,9 @@ holding the child stopped.  Try \"set detach-on-fork\" or \
            {
              target_terminal_ours_for_output ();
              fprintf_filtered (gdb_stdlog,
-                               _("Detaching after %s from "
-                                 "child process %d.\n"),
+                               _("Detaching after %s from child %s.\n"),
                                has_vforked ? "vfork" : "fork",
-                               child_pid);
+                               target_pid_to_str (child_ptid));
            }
        }
       else
@@ -472,7 +468,7 @@ holding the child stopped.  Try \"set detach-on-fork\" or \
          struct cleanup *old_chain;
 
          /* Add process to GDB's tables.  */
-         child_inf = add_inferior (child_pid);
+         child_inf = add_inferior (ptid_get_pid (child_ptid));
 
          parent_inf = current_inferior ();
          child_inf->attach_flag = parent_inf->attach_flag;
@@ -483,7 +479,7 @@ holding the child stopped.  Try \"set detach-on-fork\" or \
          old_chain = save_inferior_ptid ();
          save_current_program_space ();
 
-         inferior_ptid = ptid_build (child_pid, child_pid, 0);
+         inferior_ptid = child_ptid;
          add_thread (inferior_ptid);
          child_inf->symfile_flags = SYMFILE_NO_READ;
 
@@ -549,17 +545,16 @@ holding the child stopped.  Try \"set detach-on-fork\" or \
        {
          target_terminal_ours_for_output ();
          fprintf_filtered (gdb_stdlog,
-                           _("Attaching after process %d "
-                             "%s to child process %d.\n"),
-                           parent_pid,
+                           _("Attaching after %s %s to child %s.\n"),
+                           target_pid_to_str (parent_ptid),
                            has_vforked ? "vfork" : "fork",
-                           child_pid);
+                           target_pid_to_str (child_ptid));
        }
 
       /* Add the new inferior first, so that the target_detach below
         doesn't unpush the target.  */
 
-      child_inf = add_inferior (child_pid);
+      child_inf = add_inferior (ptid_get_pid (child_ptid));
 
       parent_inf = current_inferior ();
       child_inf->attach_flag = parent_inf->attach_flag;
@@ -596,8 +591,8 @@ holding the child stopped.  Try \"set detach-on-fork\" or \
              target_terminal_ours_for_output ();
              fprintf_filtered (gdb_stdlog,
                                _("Detaching after fork from "
-                                 "child process %d.\n"),
-                               child_pid);
+                                 "child %s.\n"),
+                               target_pid_to_str (child_ptid));
            }
 
          target_detach (NULL, 0);
@@ -609,7 +604,7 @@ holding the child stopped.  Try \"set detach-on-fork\" or \
         this new thread, before cloning the program space, and
         informing the solib layer about this new process.  */
 
-      inferior_ptid = ptid_build (child_pid, child_pid, 0);
+      inferior_ptid = child_ptid;
       add_thread (inferior_ptid);
 
       /* If this is a vfork child, then the address-space is shared

diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c
index cb10e2c..57bd1e7 100644 (file)
--- a/gdb/linux-nat.c
+++ b/gdb/linux-nat.c
@@ -387,20 +387,19 @@ linux_child_follow_fork (struct target_ops *ops, int follow_child,
       int status = W_STOPCODE (0);
       struct cleanup *old_chain;
       int has_vforked;
+      ptid_t parent_ptid, child_ptid;
       int parent_pid, child_pid;
 
       has_vforked = (inferior_thread ()->pending_follow.kind
                     == TARGET_WAITKIND_VFORKED);
-      parent_pid = ptid_get_lwp (inferior_ptid);
-      if (parent_pid == 0)
-       parent_pid = ptid_get_pid (inferior_ptid);
-      child_pid
-       = ptid_get_pid (inferior_thread ()->pending_follow.value.related_pid);
-
+      parent_ptid = inferior_ptid;
+      child_ptid = inferior_thread ()->pending_follow.value.related_pid;
+      parent_pid = ptid_get_lwp (parent_ptid);
+      child_pid = ptid_get_lwp (child_ptid);
 
       /* We're already attached to the parent, by default.  */
       old_chain = save_inferior_ptid ();
-      inferior_ptid = ptid_build (child_pid, child_pid, 0);
+      inferior_ptid = child_ptid;
       child_lp = add_lwp (inferior_ptid);
       child_lp->stopped = 1;
       child_lp->last_resume_kind = resume_stop;
@@ -457,7 +456,7 @@ linux_child_follow_fork (struct target_ops *ops, int follow_child,
        {
          struct lwp_info *parent_lp;
 
-         parent_lp = find_lwp_pid (pid_to_ptid (parent_pid));
+         parent_lp = find_lwp_pid (parent_ptid);
          gdb_assert (linux_supports_tracefork () >= 0);
 
          if (linux_supports_tracevforkdone ())