[Ada] Adjust traceback data stored for the pc symbolizer on alpha-vms
Arnaud Charlet
charlet@adacore.com
Wed Dec 19 17:54:00 GMT 2007
Tested on i686-linux, committed on trunk
The VMS service we use to symbolize a callstack traceback entry is
advertized as expecting a PC and a frame pointer to identify an
invocation and we were honoring this.
Expectedly, this only works for live invocations, which represents
a fairly severe restriction on the possible uses of this service.
We are switching back to providing a procedure value instead of a frame
pointer to circumvent this limitation, and will rely on a vms service
accepting that instead.
2007-12-19 Olivier Hainque <hainque@adacore.com>
* tb-alvms.c (struct tb_entry_t, __gnat_backtrace): Revert back to use
of Procedure Value instead of Frame Pointer as the invocation
identifier associated with the instruction pointer in each traceback
entry.
* g-trasym-vms-alpha.adb (Traceback_Entry, PV_For, FP_For,
TB_Entry_For): Revert back to use of Procedure Value instead of Frame
Pointer as the invocation identifier passed to tbk$symbolize.
* s-traent-vms.ads, s-traent-vms.adb
(Traceback_Entry, PV_For, FP_For, TB_Entry_For): Revert back to use of
Procedure Value instead of Frame Pointer as the invocation identifier
passed to tbk$symbolize.
-------------- next part --------------
Index: tb-alvms.c
===================================================================
--- tb-alvms.c (revision 130811)
+++ tb-alvms.c (working copy)
@@ -337,8 +337,8 @@ unwind_kernel_handler (frame_state_t * f
system functions need more than just a mere PC to compute info on a frame
(e.g. for non-symbolic->symbolic translation purposes). */
typedef struct {
- ADDR pc; /* instruction pointer */
- ADDR fp; /* frame pointer */
+ ADDR pc; /* Program Counter. */
+ ADDR pv; /* Procedure Value. */
} tb_entry_t;
/********************
@@ -383,7 +383,7 @@ __gnat_backtrace (void **array, int size
&& (frame_state.pc < exclude_min || frame_state.pc > exclude_max))
{
tbe->pc = (ADDR) frame_state.pc;
- tbe->fp = (ADDR) frame_state.fp;
+ tbe->pv = (ADDR) PV_FOR (frame_state.fp);
cnt ++;
tbe ++;
Index: g-trasym-vms-alpha.adb
===================================================================
--- g-trasym-vms-alpha.adb (revision 130811)
+++ g-trasym-vms-alpha.adb (working copy)
@@ -229,7 +229,7 @@ package body GNAT.Traceback.Symbolic is
(Status,
PC_For (Traceback (J)),
PC_For (Traceback (J)),
- FP_For (Traceback (J)),
+ PV_For (Traceback (J)),
Return_Address,
Image_Name_Addr,
Module_Name_Addr,
Index: s-traent-vms.ads
===================================================================
--- s-traent-vms.ads (revision 130811)
+++ s-traent-vms.ads (working copy)
@@ -40,22 +40,22 @@
package System.Traceback_Entries is
pragma Preelaborate;
- -- Symbolization is done by a VMS service which requires an instruction
- -- and a frame pointer for each traceback entry.
+ -- Symbolization is performed by a VMS service which requires more
+ -- than an instruction pointer.
type Traceback_Entry is record
- PC : System.Address;
- FP : System.Address;
+ PC : System.Address; -- Program Counter
+ PV : System.Address; -- Procedure Value
end record;
pragma Suppress_Initialization (Traceback_Entry);
Null_TB_Entry : constant Traceback_Entry :=
(PC => System.Null_Address,
- FP => System.Null_Address);
+ PV => System.Null_Address);
function PC_For (TB_Entry : Traceback_Entry) return System.Address;
- function FP_For (TB_Entry : Traceback_Entry) return System.Address;
+ function PV_For (TB_Entry : Traceback_Entry) return System.Address;
function TB_Entry_For (PC : System.Address) return Traceback_Entry;
Index: s-traent-vms.adb
===================================================================
--- s-traent-vms.adb (revision 130811)
+++ s-traent-vms.adb (working copy)
@@ -43,13 +43,13 @@ package body System.Traceback_Entries is
end PC_For;
------------
- -- FP_For --
+ -- PV_For --
------------
- function FP_For (TB_Entry : Traceback_Entry) return System.Address is
+ function PV_For (TB_Entry : Traceback_Entry) return System.Address is
begin
- return TB_Entry.FP;
- end FP_For;
+ return TB_Entry.PV;
+ end PV_For;
------------------
-- TB_Entry_For --
@@ -57,7 +57,7 @@ package body System.Traceback_Entries is
function TB_Entry_For (PC : System.Address) return Traceback_Entry is
begin
- return (PC => PC, FP => System.Null_Address);
+ return (PC => PC, PV => System.Null_Address);
end TB_Entry_For;
end System.Traceback_Entries;
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