[PATCH v2 3/8] Windows gdb: Remove mappings member from windows_per_inferior

Hannes Domani <[email protected]> Mon, 27 Jul 2026 19:42:27 +0200
Newsgroups gmane.comp.gdb.patches
Message-ID <[email protected]>
It's not really that useful, and simplifies later XState changes.
---
 gdb/aarch64-windows-nat.c |  6 ++----
 gdb/windows-nat.h         | 18 ------------------
 gdb/x86-windows-nat.c     | 34 ++++++++++++++++++++++------------
 3 files changed, 24 insertions(+), 34 deletions(-)

diff --git a/gdb/aarch64-windows-nat.c b/gdb/aarch64-windows-nat.c
index 630704a8caf..be900439047 100644
--- a/gdb/aarch64-windows-nat.c
+++ b/gdb/aarch64-windows-nat.c
@@ -168,8 +168,6 @@ aarch64_windows_nat_target::initialize_windows_arch (bool attaching)
 {
   memset (&aarch64_windows_process.dr_state, 0,
 	  sizeof (aarch64_windows_process.dr_state));
-
-  aarch64_windows_process.mappings = aarch64_mappings;
 }
 
 /* See windows-nat.h.  */
@@ -264,7 +262,7 @@ aarch64_windows_nat_target::fetch_one_register (struct regcache *regcache,
   gdb_assert (r >= 0);
 
   char *context_ptr = (char *) th->context;
-  char *context_offset = context_ptr + aarch64_windows_process.mappings[r];
+  char *context_offset = context_ptr + aarch64_mappings[r];
   struct gdbarch *gdbarch = regcache->arch ();
 
   gdb_assert (!gdbarch_read_pc_p (gdbarch));
@@ -296,7 +294,7 @@ aarch64_windows_nat_target::store_one_register (const struct regcache *regcache,
 
   char *context_ptr = (char *) th->context;
 
-  regcache->raw_collect (r, context_ptr + aarch64_windows_process.mappings[r]);
+  regcache->raw_collect (r, context_ptr + aarch64_mappings[r]);
 }
 
 /* See windows-nat.h.  */
diff --git a/gdb/windows-nat.h b/gdb/windows-nat.h
index 3349755022b..d6977ff4c85 100644
--- a/gdb/windows-nat.h
+++ b/gdb/windows-nat.h
@@ -139,24 +139,6 @@ struct windows_per_inferior : public windows_nat::windows_process_info
   void *wow64_dbgbreak = nullptr;
 #endif
 
-  /* This vector maps GDB's idea of a register's number into an offset
-     in the windows exception context vector.
-
-     It also contains the bit mask needed to load the register in question.
-
-     The contents of this table can only be computed by the units
-     that provide CPU-specific support for Windows native debugging.
-
-     One day we could read a reg, we could inspect the context we
-     already have loaded, if it doesn't have the bit set that we need,
-     we read that set of registers in using GetThreadContext.  If the
-     context already contains what we need, we just unpack it.  Then to
-     write a register, first we have to ensure that the context contains
-     the other regs of the group, and then we copy the info in and set
-     out bit.  */
-
-  const int *mappings = nullptr;
-
   std::vector<windows_solib> solibs;
 
 #ifdef __CYGWIN__
diff --git a/gdb/x86-windows-nat.c b/gdb/x86-windows-nat.c
index 2f556e47b39..b3ad8594020 100644
--- a/gdb/x86-windows-nat.c
+++ b/gdb/x86-windows-nat.c
@@ -85,16 +85,10 @@ x86_windows_nat_target::initialize_windows_arch (bool attaching)
     = !attaching && x86_windows_process.wow64_process;
 
   if (!x86_windows_process.wow64_process)
-    {
-      x86_windows_process.mappings = amd64_mappings;
-      x86_windows_process.segment_register_p = amd64_windows_segment_register_p;
-    }
+    x86_windows_process.segment_register_p = amd64_windows_segment_register_p;
   else
 #endif
-    {
-      x86_windows_process.mappings = i386_mappings;
-      x86_windows_process.segment_register_p = i386_windows_segment_register_p;
-    }
+    x86_windows_process.segment_register_p = i386_windows_segment_register_p;
 }
 
 /* See windows-nat.h.  */
@@ -242,7 +236,15 @@ x86_windows_nat_target::fetch_one_register (struct regcache *regcache,
       return (char *) context;
     });
 
-  char *context_offset = context_ptr + x86_windows_process.mappings[r];
+  const int *mappings;
+#ifdef __x86_64__
+  if (!x86_windows_process.wow64_process)
+    mappings = amd64_mappings;
+  else
+#endif
+    mappings = i386_mappings;
+
+  char *context_offset = context_ptr + mappings[r];
   struct gdbarch *gdbarch = regcache->arch ();
   i386_gdbarch_tdep *tdep = gdbarch_tdep<i386_gdbarch_tdep> (gdbarch);
 
@@ -308,6 +310,14 @@ x86_windows_nat_target::store_one_register (const struct regcache *regcache,
       return (char *) context;
     });
 
+  const int *mappings;
+#ifdef __x86_64__
+  if (!x86_windows_process.wow64_process)
+    mappings = amd64_mappings;
+  else
+#endif
+    mappings = i386_mappings;
+
   struct gdbarch *gdbarch = regcache->arch ();
   i386_gdbarch_tdep *tdep = gdbarch_tdep<i386_gdbarch_tdep> (gdbarch);
 
@@ -319,7 +329,7 @@ x86_windows_nat_target::store_one_register (const struct regcache *regcache,
     {
       gdb_byte bytes[4];
       regcache->raw_collect (r, bytes);
-      memcpy (context_ptr + x86_windows_process.mappings[r], bytes, 2);
+      memcpy (context_ptr + mappings[r], bytes, 2);
     }
   else if (r == I387_FOP_REGNUM (tdep))
     {
@@ -328,10 +338,10 @@ x86_windows_nat_target::store_one_register (const struct regcache *regcache,
       /* The value of FOP occupies the top two bytes in the context,
 	 so write the two low-order bytes from the cache into the
 	 appropriate spot.  */
-      memcpy (context_ptr + x86_windows_process.mappings[r] + 2, bytes, 2);
+      memcpy (context_ptr + mappings[r] + 2, bytes, 2);
     }
   else
-    regcache->raw_collect (r, context_ptr + x86_windows_process.mappings[r]);
+    regcache->raw_collect (r, context_ptr + mappings[r]);
 }
 
 /* See windows-nat.h.  */
-- 
2.54.0