[PATCHv5 06/11] gdb/gdbserver: share I386_LINUX_XSAVE_XCR0_OFFSET definition

[Andrew Burgess <aburgess@redhat.com>]

Share the definition of I386_LINUX_XSAVE_XCR0_OFFSET between GDB and
gdbserver.

This commit is part of a series that aims to share more of the x86
target description creation code between GDB and gdbserver.  The
I386_LINUX_XSAVE_XCR0_OFFSET #define is used as part of the target
description creation, and I noticed that this constant is defined
separately for GDB and gdbserver.

This commit moves the definition into gdbsupport/x86-xstate.h, which
allows the #define to be shared.

There should be no user visible changes after this commit.
---
 gdb/i386-linux-tdep.h      | 20 --------------------
 gdbserver/linux-x86-low.cc | 21 ---------------------
 gdbsupport/x86-xstate.h    | 20 ++++++++++++++++++++
 3 files changed, 20 insertions(+), 41 deletions(-)

diff --git a/gdb/i386-linux-tdep.h b/gdb/i386-linux-tdep.h
index 5891747572b..07593c6a8ec 100644
--- a/gdb/i386-linux-tdep.h
+++ b/gdb/i386-linux-tdep.h
@@ -58,26 +58,6 @@ extern void i386_linux_report_signal_info (struct gdbarch *gdbarch,
 /* Return the target description according to XCR0.  */
 extern const struct target_desc *i386_linux_read_description (uint64_t xcr0);
 
-/* Format of XSAVE extended state is:
-	struct
-	{
-	  fxsave_bytes[0..463]
-	  sw_usable_bytes[464..511]
-	  xstate_hdr_bytes[512..575]
-	  extended state regions (AVX, MPX, AVX512, PKRU, etc.)
-	};
-
-  Same memory layout will be used for the coredump NT_X86_XSTATE
-  representing the XSAVE extended state registers.
-
-  The first 8 bytes of the sw_usable_bytes[464..467] is the OS enabled
-  extended state mask, which is the same as the extended control register
-  0 (the XFEATURE_ENABLED_MASK register), XCR0.  We can use this mask
-  together with the mask saved in the xstate_hdr_bytes to determine what
-  states the processor/OS supports and what state, used or initialized,
-  the process/thread is in.  */ 
-#define I386_LINUX_XSAVE_XCR0_OFFSET 464
-
 extern int i386_linux_gregset_reg_offset[];
 
 /* Return x86 siginfo type.  */
diff --git a/gdbserver/linux-x86-low.cc b/gdbserver/linux-x86-low.cc
index ffb2a90731d..62612773a87 100644
--- a/gdbserver/linux-x86-low.cc
+++ b/gdbserver/linux-x86-low.cc
@@ -831,27 +831,6 @@ x86_target::low_siginfo_fixup (siginfo_t *ptrace, gdb_byte *inf, int direction)
 \f
 static int use_xml;
 
-/* Format of XSAVE extended state is:
-	struct
-	{
-	  fxsave_bytes[0..463]
-	  sw_usable_bytes[464..511]
-	  xstate_hdr_bytes[512..575]
-	  avx_bytes[576..831]
-	  future_state etc
-	};
-
-  Same memory layout will be used for the coredump NT_X86_XSTATE
-  representing the XSAVE extended state registers.
-
-  The first 8 bytes of the sw_usable_bytes[464..467] is the OS enabled
-  extended state mask, which is the same as the extended control register
-  0 (the XFEATURE_ENABLED_MASK register), XCR0.  We can use this mask
-  together with the mask saved in the xstate_hdr_bytes to determine what
-  states the processor/OS supports and what state, used or initialized,
-  the process/thread is in.  */
-#define I386_LINUX_XSAVE_XCR0_OFFSET 464
-
 /* Get Linux/x86 target description from running target.  */
 
 static const struct target_desc *
diff --git a/gdbsupport/x86-xstate.h b/gdbsupport/x86-xstate.h
index 89c1143fbe1..11b37544aa3 100644
--- a/gdbsupport/x86-xstate.h
+++ b/gdbsupport/x86-xstate.h
@@ -120,4 +120,24 @@ constexpr bool operator!= (const x86_xsave_layout &lhs,
 
 #define I387_MXCSR_INIT_VAL 0x1f80
 
+/* Format of XSAVE extended state is:
+	struct
+	{
+	  fxsave_bytes[0..463]
+	  sw_usable_bytes[464..511]
+	  xstate_hdr_bytes[512..575]
+	  extended state regions (AVX, MPX, AVX512, PKRU, etc.)
+	};
+
+  Same memory layout will be used for the coredump NT_X86_XSTATE
+  representing the XSAVE extended state registers.
+
+  The first 8 bytes of the sw_usable_bytes[464..467] is the OS enabled
+  extended state mask, which is the same as the extended control register
+  0 (the XFEATURE_ENABLED_MASK register), XCR0.  We can use this mask
+  together with the mask saved in the xstate_hdr_bytes to determine what
+  states the processor/OS supports and what state, used or initialized,
+  the process/thread is in.  */
+#define I386_LINUX_XSAVE_XCR0_OFFSET 464
+
 #endif /* COMMON_X86_XSTATE_H */
-- 
2.25.4