From: John Baldwin <jhb@FreeBSD.org>
Date: Wed, 16 Nov 2022 01:35:09 +0000 (-0800)
Subject: gdb tdesc: Handle mismatched pointer register types.
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4695a547e1f2f7b25598a43544707a3f7651ec9d;p=thirdparty%2Fbinutils-gdb.git

gdb tdesc: Handle mismatched pointer register types.

In the XML target descriptions, registers can be given a type of
"code_ptr" or "data_ptr".  GDB always uses the builtin type for "void
*" for these registers.  However, this is wrong if the register's size
does not match (e.g. the legacy "sp" and "pc" ARM64 registers when
using a purecap binary for which "void *" is a capability).  If the
sizes don't match, try to find a matching type such as "long" or
"intcap_t" to use instead.
---

diff --git a/gdb/target-descriptions.c b/gdb/target-descriptions.c
index 5b886f49872..a00300995b7 100644
--- a/gdb/target-descriptions.c
+++ b/gdb/target-descriptions.c
@@ -945,7 +945,24 @@ tdesc_register_type (struct gdbarch *gdbarch, int regno)
     {
       /* First check for a predefined or target defined type.  */
       if (reg->tdesc_type)
-	arch_reg->type = make_gdb_type (gdbarch, reg->tdesc_type);
+	{
+	  if ((reg->type == "code_ptr" || reg->type == "data_ptr")
+	      && reg->bitsize != gdbarch_ptr_bit (gdbarch))
+	    {
+	      if (reg->bitsize == gdbarch_long_bit (gdbarch))
+		arch_reg->type = builtin_type (gdbarch)->builtin_long;
+	      else if (reg->bitsize == gdbarch_capability_bit (gdbarch))
+		arch_reg->type = builtin_type (gdbarch)->builtin_data_capability;
+	      else
+		{
+		  warning (_("Register \"%s\" has an unsupported size (%d bits)"),
+			   reg->name.c_str (), reg->bitsize);
+		  arch_reg->type = builtin_type (gdbarch)->builtin_data_ptr;
+		}
+	    }
+	  else
+	    arch_reg->type = make_gdb_type (gdbarch, reg->tdesc_type);
+	}
 
       /* Next try size-sensitive type shortcuts.  */
       else if (reg->type == "float")