Retrieve segment registers on Windows amd64

Message ID 20150227084945.GG31815@adacore.com
State New, archived
Headers

Commit Message

Joel Brobecker Feb. 27, 2015, 8:49 a.m. UTC
  > Thanks for taking a look.
> 
> Patch with ChangeLog amended as you suggest attached.

Excellent. Checked in with a small adjustment, as I noticed
that one of the lines ended up being too long, and I missed
that during the first review (I was more worried about the
portability across Windows versions)...

Attached is what I just pushed.

> Hopefully, I will have a few more patches, so yes please.

I'll send it to you privately.
  

Patch

From f0666312fd86272e0234d5f7c92d8f65d5c6505e Mon Sep 17 00:00:00 2001
From: Jon TURNEY <jon.turney@dronecode.org.uk>
Date: Wed, 18 Feb 2015 23:13:47 +0000
Subject: [PATCH] Retrieve segment registers on Windows amd64

For amd64, CONTEXT_FULL does not contain CONTEXT_SEGMENTS, which seems
to be needed to retrieve all the segment registers.  Add it explicitly,
with a little de-cruftification.

The value of the segment registers isn't terribly useful on amd64, but
at least this makes the output of 'info registers' correct.

Before:

    (gdb)  i r cs ss ds es fs gs
    cs             0x33     51
    ss             0x2b     43
    ds             0x0      0
    es             0x0      0
    fs             0x0      0
    gs             0x0      0

After:

    (gdb) i r cs ss ds es fs gs
    cs             0x33     51
    ss             0x2b     43
    ds             0x2b     43
    es             0x2b     43
    fs             0x53     83
    gs             0x2b     43

gdb/ChangeLog

2015-02-27  Jon TURNEY  <jon.turney@dronecode.org.uk>

	* windows-nat.c (CONTEXT_DEBUGGER): Remove.
	(CONTEXT_DEBUGGER_DR): Add CONTEXT_SEGMENTS.  Incorporate flags
	from CONTEXT_DEBUGGER.
---
 gdb/ChangeLog     | 6 ++++++
 gdb/windows-nat.c | 6 +++---
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index fac8b37..ff0e72d 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@ 
+2015-02-27  Jon TURNEY  <jon.turney@dronecode.org.uk>
+
+	* windows-nat.c (CONTEXT_DEBUGGER): Remove.
+	(CONTEXT_DEBUGGER_DR): Add CONTEXT_SEGMENTS.  Incorporate flags
+	from CONTEXT_DEBUGGER.
+
 2015-02-26  Doug Evans  <dje@google.com>
 
 	* gdbtypes.c (internal_type_vptr_fieldno): Add missing call to
diff --git a/gdb/windows-nat.c b/gdb/windows-nat.c
index 9c2dca1..107bdf2 100644
--- a/gdb/windows-nat.c
+++ b/gdb/windows-nat.c
@@ -130,7 +130,6 @@  static CONTEXT saved_context;	/* Containes the saved context from a
 enum
   {
     FLAG_TRACE_BIT = 0x100,
-    CONTEXT_DEBUGGER = (CONTEXT_FULL | CONTEXT_FLOATING_POINT)
   };
 #endif
 
@@ -140,8 +139,9 @@  enum
 #define CONTEXT_EXTENDED_REGISTERS 0
 #endif
 
-#define CONTEXT_DEBUGGER_DR CONTEXT_DEBUGGER | CONTEXT_DEBUG_REGISTERS \
-	| CONTEXT_EXTENDED_REGISTERS
+#define CONTEXT_DEBUGGER_DR CONTEXT_FULL | CONTEXT_FLOATING_POINT \
+        | CONTEXT_SEGMENTS | CONTEXT_DEBUG_REGISTERS \
+        | CONTEXT_EXTENDED_REGISTERS
 
 static uintptr_t dr[8];
 static int debug_registers_changed;
-- 
1.9.1