Arm: Add read_description read funcs and use in GDB

Switch the Arm target to get target descriptions via arm_read_description
and aarch32_read_description, in the same style as other feature targets.
Add an enum to specify the different types - this will also be of use to
gdbserver in a later patch.

Under the hood return the same existing pre-feature target descriptions.

gdb/ChangeLog:

	* Makefile.in: Add new files.
	* aarch32-tdep.c: New file.
	* aarch32-tdep.h: New file.
	* aarch64-linux-nat.c (aarch64_linux_nat_target::read_description):
	Call aarch32_read_description.
	* arch/aarch32.c: New file.
	* arch/aarch32.h: New file.
	* arch/arm.c (arm_create_target_description)
	(arm_create_mprofile_target_description): New function.
	* arch/arm.h (arm_fp_type, arm_m_profile_type): New enum.
	(arm_create_target_description)
	(arm_create_mprofile_target_description): New declaration.
	* arm-fbsd-tdep.c (arm_fbsd_read_description_auxv): Call
	read_description functions.
	* arm-linux-nat.c (arm_linux_nat_target::read_description):
	Likewise.
	* arm-linux-tdep.c (arm_linux_core_read_description): Likewise.
	* arm-tdep.c (tdesc_arm_list): New variable.
	(arm_register_g_packet_guesses): Call create description functions.
	(arm_read_description) (arm_read_mprofile_description): New
	function.
	* arm-tdep.h (arm_read_description)
	(arm_read_mprofile_description): Add declaration.
	* configure.tgt: Add new files.

4 files changed, 143 insertions, 0 deletions

diff --git a/gdb/arch/aarch32.c b/gdb/arch/aarch32.c
new file mode 100644
index 0000000..14d6987
--- /dev/null
+++ b/gdb/arch/aarch32.c
@@ -0,0 +1,29 @@
+/* Copyright (C) 2019 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include "gdbsupport/common-defs.h"
+#include "aarch32.h"
+
+extern struct target_desc *tdesc_arm_with_neon;
+
+/* See aarch32.h.  */
+
+target_desc *
+aarch32_create_target_description ()
+{
+  return tdesc_arm_with_neon;
+}
diff --git a/gdb/arch/aarch32.h b/gdb/arch/aarch32.h
new file mode 100644
index 0000000..d2c0047
--- /dev/null
+++ b/gdb/arch/aarch32.h
@@ -0,0 +1,27 @@
+/* Copyright (C) 2019 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#ifndef ARCH_AARCH32_H
+#define ARCH_AARCH32_H
+
+#include "gdbsupport/tdesc.h"
+
+/* Create the AArch32 target description.  */
+
+target_desc *aarch32_create_target_description ();
+
+#endif /* aarch32.h.  */
diff --git a/gdb/arch/arm.c b/gdb/arch/arm.c
index 860ce02..7a0f36e 100644
--- a/gdb/arch/arm.c
+++ b/gdb/arch/arm.c
@@ -21,6 +21,17 @@
 #include "gdbsupport/common-regcache.h"
 #include "arm.h"
 
+extern struct target_desc *tdesc_arm_with_vfpv2;
+extern struct target_desc *tdesc_arm_with_vfpv3;
+extern struct target_desc *tdesc_arm_with_iwmmxt;
+
+/* Temporary ifdef.  Will be removed when target descriptions are switched.  */
+#ifndef GDBSERVER
+extern struct target_desc *tdesc_arm_with_m;
+extern struct target_desc *tdesc_arm_with_m_vfp_d16;
+extern struct target_desc *tdesc_arm_with_m_fpa_layout;
+#endif
+
 /* See arm.h.  */
 
 int
@@ -372,3 +383,52 @@ shifted_reg_val (struct regcache *regcache, unsigned long inst,
 
   return res & 0xffffffff;
 }
+
+/* See arch/arm.h.  */
+
+target_desc *
+arm_create_target_description (arm_fp_type fp_type)
+{
+  switch (fp_type)
+    {
+    case ARM_FP_TYPE_NONE:
+      return nullptr;
+/* Temporary ifdef.  Will be removed when target descriptions are switched.  */
+#ifndef GDBSERVER
+    case ARM_FP_TYPE_VFPV2:
+      return tdesc_arm_with_vfpv2;
+
+    case ARM_FP_TYPE_VFPV3:
+      return tdesc_arm_with_vfpv3;
+
+    case ARM_FP_TYPE_IWMMXT:
+      return tdesc_arm_with_iwmmxt;
+#endif
+    default:
+      error (_("Invalid Arm FP type: %d"), fp_type);
+    }
+}
+
+/* See arch/arm.h.  */
+
+target_desc *
+arm_create_mprofile_target_description (arm_m_profile_type m_type)
+{
+  switch (m_type)
+    {
+/* Temporary ifdef.  Will be removed when target descriptions are switched.  */
+#ifndef GDBSERVER
+    case ARM_M_TYPE_M_PROFILE:
+      return tdesc_arm_with_m;
+
+    case ARM_M_TYPE_VFP_D16:
+      return tdesc_arm_with_m_fpa_layout;
+
+    case ARM_M_TYPE_WITH_FPA:
+      return tdesc_arm_with_m_vfp_d16;
+#endif
+    default:
+      error (_("Invalid Arm M type: %d"), m_type);
+    }
+}
+
diff --git a/gdb/arch/arm.h b/gdb/arch/arm.h
index dfbbd56..58511c7 100644
--- a/gdb/arch/arm.h
+++ b/gdb/arch/arm.h
@@ -19,6 +19,8 @@
 #ifndef ARCH_ARM_H
 #define ARCH_ARM_H
 
+#include "gdbsupport/tdesc.h"
+
 /* Register numbers of various important registers.  */
 
 enum gdb_regnum {
@@ -66,6 +68,23 @@ enum arm_breakpoint_kinds
    ARM_BP_KIND_ARM = 4,
 };
 
+/* Supported Arm FP hardware types.  */
+enum arm_fp_type {
+   ARM_FP_TYPE_NONE = 0,
+   ARM_FP_TYPE_VFPV2,
+   ARM_FP_TYPE_VFPV3,
+   ARM_FP_TYPE_IWMMXT,
+   ARM_FP_TYPE_INVALID
+};
+
+/* Supported M-profile Arm types.  */
+enum arm_m_profile_type {
+   ARM_M_TYPE_M_PROFILE,
+   ARM_M_TYPE_VFP_D16,
+   ARM_M_TYPE_WITH_FPA,
+   ARM_M_TYPE_INVALID
+};
+
 /* Instruction condition field values.  */
 #define INST_EQ		0x0
 #define INST_NE		0x1
@@ -165,4 +184,12 @@ unsigned long shifted_reg_val (struct regcache *regcache,
 			       unsigned long pc_val,
 			       unsigned long status_reg);
 
+/* Create an Arm target description with the given FP hardware type.  */
+
+target_desc *arm_create_target_description (arm_fp_type fp_type);
+
+/* Create an Arm M-profile target description with the given hardware type.  */
+
+target_desc *arm_create_mprofile_target_description (arm_m_profile_type m_type);
+
 #endif /* ARCH_ARM_H */