add set cp-abi command

[Jim Ingham <jingham@apple.com>]

Hi, all...

gdb assumes that it will never see a mix of gcc2 & gcc3 compiled C++ 
code in a single executable.  So it determines which abi to use by 
setting it to gnu-v2, and then if it EVER sees a v3 style mangled name, 
it switches it to v3.  This breaks down in the case where you have some 
shared libraries compiled with gcc3, but the user code is compiled with 
gcc2.  This is a perfectly okay thing to do if the libraries don't 
export any C++ symbols, but gdb will get the abi wrong, and you won't be 
able to print any C++ objects in the user code.  Ouch!

I am not currently proposing any fancy mechanism to try to switch on the 
fly between the two.  The problem is temporary so I don't really think 
it is worth the effort to cook up such a scheme.  Rather, I just added a 
"set cp-abi" command so that my users can fix the problem by hand when 
they notice it arising.

Here is the patch:

2002-03-12  James Ingham <jingham@apple.com>

         * cp-abi.c (set_cp_abi_cmd, show_cp_abi_cmd,
         show_cp_abis_cmd): New functions, allow you to set & show
         cplus abi's in case gdb gets it wrong.
         (_initialize_cp_abi): Define the cp-abi switching commands.


Index: cp-abi.c
===================================================================
RCS file: /cvs/src/src/gdb/cp-abi.c,v
retrieving revision 1.3
diff -c -w -r1.3 cp-abi.c
*** cp-abi.c    2002/01/04 18:20:19     1.3
--- cp-abi.c    2002/03/13 18:46:57
***************
*** 21,26 ****
--- 21,29 ----
   #include "defs.h"
   #include "value.h"
   #include "cp-abi.h"
+ #include "command.h"
+ #include "ui-out.h"
+ #include "gdbcmd.h"

   struct cp_abi_ops current_cp_abi;

***************
*** 103,109 ****
--- 106,164 ----
     int i;
     for (i = 0; i < num_cp_abis; i++)
       if (strcmp (cp_abis[i].shortname, short_name) == 0)
+       {
         current_cp_abi = cp_abis[i];
         return 1;
+       }
+
+   return 0;
+ }
+
+ void
+ set_cp_abi_cmd (char *args, int from_tty)
+ {
+
+   if (!switch_to_cp_abi (args))
+     error ("Could not find ABI: \"%s\" in ABI list\n", args);
+ }
+
+ void
+ show_cp_abi_cmd (char *args, int from_tty)
+ {
+   ui_out_text (uiout, "The current cplus abi is: ");
+
+   ui_out_field_string (uiout, "cp-abi", current_cp_abi.shortname);
+   ui_out_text (uiout, ".\n");
+ }
+
+ void
+ show_cp_abis_cmd (char *args, int from_tty)
+ {
+   int i;
+   ui_out_text (uiout, "The valid cplus abi's are:\n");
+
+   ui_out_tuple_begin (uiout, "cp-abi-list");
+   for (i = 0; i < num_cp_abis; i++)
+     {
+       ui_out_field_string (uiout, "cp-abi", cp_abis[i].shortname);
+       ui_out_text (uiout, "\n");
+     }
+   ui_out_tuple_end (uiout);
+
+ }
+
+ void
+ _initialize_cp_abi (void)
+ {
+   struct cmd_list_element *cmd;
+
+   cmd = add_cmd ("cp-abi", class_obscure , set_cp_abi_cmd,
+                "Set the ABI used for inspecting C++ objects", 
&setlist);
+
+   cmd = add_cmd ("cp-abi", class_obscure, show_cp_abi_cmd,
+                "Show the ABI used for inspecting C++ objects", 
&showlist);
+   cmd = add_cmd ("cp-abis", class_obscure, show_cp_abis_cmd,
+                "List the available ABIs for inspecting C++ objects", 
&showlist);
+
   }

Jim
--
Jim Ingham                                   jingham@apple.com
Developer Tools - gdb
Apple Computer