* gdbarch.sh (gdbarch_update_p): Swap out the old architecture

before probing for a new one.  Detect errorenous gdbarch_init
functions.
* gdbarch.c: Regenerate.

3 files changed, 49 insertions, 28 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 90c06f4..8a235dd 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,10 @@
+2002-05-02  Andrew Cagney  <cagney@redhat.com>
+
+	* gdbarch.sh (gdbarch_update_p): Swap out the old architecture
+	before probing for a new one.  Detect errorenous gdbarch_init
+	functions.
+	* gdbarch.c: Regenerate.
+
 2002-05-01  Andrew Cagney  <cagney@redhat.com>
 
 	* config/mn10200/tm-mn10200.h: Include "symfile.h" and "symtab.h".
diff --git a/gdb/gdbarch.c b/gdb/gdbarch.c
index f7248fc..ff5072d 100644
--- a/gdb/gdbarch.c
+++ b/gdb/gdbarch.c
@@ -4887,6 +4887,7 @@ int
 gdbarch_update_p (struct gdbarch_info info)
 {
   struct gdbarch *new_gdbarch;
+  struct gdbarch *old_gdbarch;
   struct gdbarch_registration *rego;
 
   /* Fill in missing parts of the INFO struct using a number of
@@ -4955,30 +4956,40 @@ gdbarch_update_p (struct gdbarch_info info)
       return 0;
     }
 
+  /* Swap the data belonging to the old target out.  This stops the
+     ->init() function trying to refer to the previous architecture.  */
+  swapout_gdbarch_swap (current_gdbarch);
+  init_gdbarch_swap (current_gdbarch);
+  old_gdbarch = current_gdbarch;
+  current_gdbarch = NULL;
+
   /* Ask the target for a replacement architecture. */
   new_gdbarch = rego->init (info, rego->arches);
 
-  /* Did the target like it?  No. Reject the change. */
+  /* Did the target like it?  No. Reject the change and revert to the
+     old architecture.  */
   if (new_gdbarch == NULL)
     {
       if (gdbarch_debug)
 	fprintf_unfiltered (gdb_stdlog, "gdbarch_update: Target rejected architecture\n");
+      swapin_gdbarch_swap (old_gdbarch);
+      current_gdbarch = old_gdbarch;
       return 0;
     }
 
-  /* Did the architecture change?  No. Do nothing. */
-  if (current_gdbarch == new_gdbarch)
+  /* Did the architecture change?  No.  Oops, put the old architecture
+     back.  */
+  if (old_gdbarch == new_gdbarch)
     {
       if (gdbarch_debug)
 	fprintf_unfiltered (gdb_stdlog, "gdbarch_update: Architecture 0x%08lx (%s) unchanged\n",
 			    (long) new_gdbarch,
 			    new_gdbarch->bfd_arch_info->printable_name);
+      swapin_gdbarch_swap (old_gdbarch);
+      current_gdbarch = old_gdbarch;
       return 1;
     }
 
-  /* Swap all data belonging to the old target out */
-  swapout_gdbarch_swap (current_gdbarch);
-
   /* Is this a pre-existing architecture?  Yes. Move it to the front
      of the list of architectures (keeping the list sorted Most
      Recently Used) and then copy it in.  */
@@ -5035,14 +5046,10 @@ gdbarch_update_p (struct gdbarch_info info)
   new_gdbarch->dump_tdep = rego->dump_tdep;
   verify_gdbarch (new_gdbarch);
 
-  /* Initialize the per-architecture memory (swap) areas.
-     CURRENT_GDBARCH must be update before these modules are
-     called. */
-  init_gdbarch_swap (new_gdbarch);
-  
-  /* Initialize the per-architecture data-pointer of all parties that
-     registered an interest in this architecture.  CURRENT_GDBARCH
-     must be updated before these modules are called. */
+  /* Initialize the per-architecture data-pointers and swap areas for
+     all parties that registered an interest in this architecture.
+     CURRENT_GDBARCH must be updated before these modules are called.
+     The swap area's will have already been initialized to zero.  */
   init_gdbarch_data (new_gdbarch);
   architecture_changed_event ();
 
diff --git a/gdb/gdbarch.sh b/gdb/gdbarch.sh
index e1442f3..f99d29a 100755
--- a/gdb/gdbarch.sh
+++ b/gdb/gdbarch.sh
@@ -2079,6 +2079,7 @@ int
 gdbarch_update_p (struct gdbarch_info info)
 {
   struct gdbarch *new_gdbarch;
+  struct gdbarch *old_gdbarch;
   struct gdbarch_registration *rego;
 
   /* Fill in missing parts of the INFO struct using a number of
@@ -2147,30 +2148,40 @@ gdbarch_update_p (struct gdbarch_info info)
       return 0;
     }
 
+  /* Swap the data belonging to the old target out.  This stops the
+     ->init() function trying to refer to the previous architecture.  */
+  swapout_gdbarch_swap (current_gdbarch);
+  init_gdbarch_swap (current_gdbarch);
+  old_gdbarch = current_gdbarch;
+  current_gdbarch = NULL;
+
   /* Ask the target for a replacement architecture. */
   new_gdbarch = rego->init (info, rego->arches);
 
-  /* Did the target like it?  No. Reject the change. */
+  /* Did the target like it?  No. Reject the change and revert to the
+     old architecture.  */
   if (new_gdbarch == NULL)
     {
       if (gdbarch_debug)
 	fprintf_unfiltered (gdb_stdlog, "gdbarch_update: Target rejected architecture\\n");
+      swapin_gdbarch_swap (old_gdbarch);
+      current_gdbarch = old_gdbarch;
       return 0;
     }
 
-  /* Did the architecture change?  No. Do nothing. */
-  if (current_gdbarch == new_gdbarch)
+  /* Did the architecture change?  No.  Oops, put the old architecture
+     back.  */
+  if (old_gdbarch == new_gdbarch)
     {
       if (gdbarch_debug)
 	fprintf_unfiltered (gdb_stdlog, "gdbarch_update: Architecture 0x%08lx (%s) unchanged\\n",
 			    (long) new_gdbarch,
 			    new_gdbarch->bfd_arch_info->printable_name);
+      swapin_gdbarch_swap (old_gdbarch);
+      current_gdbarch = old_gdbarch;
       return 1;
     }
 
-  /* Swap all data belonging to the old target out */
-  swapout_gdbarch_swap (current_gdbarch);
-
   /* Is this a pre-existing architecture?  Yes. Move it to the front
      of the list of architectures (keeping the list sorted Most
      Recently Used) and then copy it in.  */
@@ -2227,14 +2238,10 @@ gdbarch_update_p (struct gdbarch_info info)
   new_gdbarch->dump_tdep = rego->dump_tdep;
   verify_gdbarch (new_gdbarch);
 
-  /* Initialize the per-architecture memory (swap) areas.
-     CURRENT_GDBARCH must be update before these modules are
-     called. */
-  init_gdbarch_swap (new_gdbarch);
-  
-  /* Initialize the per-architecture data-pointer of all parties that
-     registered an interest in this architecture.  CURRENT_GDBARCH
-     must be updated before these modules are called. */
+  /* Initialize the per-architecture data-pointers and swap areas for
+     all parties that registered an interest in this architecture.
+     CURRENT_GDBARCH must be updated before these modules are called.
+     The swap area's will have already been initialized to zero.  */
   init_gdbarch_data (new_gdbarch);
   architecture_changed_event ();