GitLab

This is an early test that was mistakenly pushed. Remove it.

gdb/testsuite/ChangeLog:

YYYY-MM-DD  Luis Machado  <luis.machado@arm.com>

	* gdb.dwarf2/dw2-capability.exp: Remove file.

This patch implements passing/returning of parameters for Morello.  It is
implemented based on the Morello AAPCS64 document and supports both the hybrid
AAPCS64 and Pure-Cap AAPCS64-CAP ABI's.

gdb/ChangeLog

2021-02-26  Luis Machado  <luis.machado@arm.com>

	* aarch64-tdep.c (struct stack_item_t) <arg_value): New field.
	(set_register_tag, pass_in_c, pass_in_c_or_stack,
	pass_in_c_x_or_stack, type_fields_overlap_capabilities,
	convert_pointer_to_capability,
	morello_write_memory_with_capabilities,
	morello_push_dummy_call, morello_extract_return_value,
	morello_return_in_memory, morello_store_return_value,
	morello_return_value): New functions.
	(pass_in_x, pass_in_v, pass_on_stack, pass_in_x_or_stack,
	pass_in_v_vfp_candidate): Update.
	(aarch64_return_value): New argument value.
	(aarch64_gdbarch_init): Conditionally set both gdbarch_push_dummy_call
	and gdbarch_return_value.
	* arch/aarch64.h (MORELLO_MEMORY_TAG_GRANULE_SIZE): New constant.
	* dwarf2/read.c (handle_struct_member_die): Record whether the
	composite type contains capabilities.
	* gdbarch.sh (return_value): New argument value.
	* gdbarch.c: Regenerate.
	* gdbarch.h: Regenerate.
	* gdbtypes.c (recursive_dump_type): Dump extra information.
	(append_composite_type_field_raw): Set whether the composite type
	constains capabilities.
	* gdbtypes.h (struct main_type) <m_flag_contains_capability>: New field.
	<contains_capability>: New member function.
	<set_contains_capability>: New member function.

	* alpha-tdep.c: Update return_value hook prototype.
	* amd64-tdep.c: Update return_value hook prototype.
	* amd64-windows-tdep.c: Update return_value hook prototype.
	* arc-tdep.c: Update return_value hook prototype.
	* arm-tdep.c: Update return_value hook prototype.
	* avr-tdep.c: Update return_value hook prototype.
	* bfin-tdep.c: Update return_value hook prototype.
	* bpf-tdep.c: Update return_value hook prototype.
	* cris-tdep.c: Update return_value hook prototype.
	* csky-tdep.c: Update return_value hook prototype.
	* elfread.c: Update return_value hook prototype.
	* frv-tdep.c: Update return_value hook prototype.
	* ft32-tdep.c: Update return_value hook prototype.
	* h8300-tdep.c: Update return_value hook prototype.
	* hppa-tdep.c: Update return_value hook prototype.
	* i386-tdep.c: Update return_value hook prototype.
	* ia64-tdep.c: Update return_value hook prototype.
	* infcall.c: Update return_value hook prototype.
	* infcmd.c: Update return_value hook prototype.
	* lm32-tdep.c: Update return_value hook prototype.
	* m32c-tdep.c: Update return_value hook prototype.
	* m32r-tdep.c: Update return_value hook prototype.
	* m68hc11-tdep.c: Update return_value hook prototype.
	* m68k-tdep.c: Update return_value hook prototype.
	* mep-tdep.c: Update return_value hook prototype.
	* microblaze-tdep.c: Update return_value hook prototype.
	* mips-tdep.c: Update return_value hook prototype.
	* mn10300-tdep.c: Update return_value hook prototype.
	* moxie-tdep.c: Update return_value hook prototype.
	* msp430-tdep.c: Update return_value hook prototype.
	* nds32-tdep.c: Update return_value hook prototype.
	* nios2-tdep.c: Update return_value hook prototype.
	* or1k-tdep.c: Update return_value hook prototype.
	* ppc-fbsd-tdep.c: Update return_value hook prototype.
	* ppc-linux-tdep.c: Update return_value hook prototype.
	* ppc-netbsd-tdep.c: Update return_value hook prototype.
	* ppc-sysv-tdep.c: Update return_value hook prototype.
	* riscv-tdep.c: Update return_value hook prototype.
	* rl78-tdep.c: Update return_value hook prototype.
	* rs6000-aix-tdep.c: Update return_value hook prototype.
	* rs6000-lynx178-tdep.c: Update return_value hook prototype.
	* rx-tdep.c: Update return_value hook prototype.
	* s12z-tdep.c: Update return_value hook prototype.
	* s390-tdep.c: Update return_value hook prototype.
	* score-tdep.c: Update return_value hook prototype.
	* sh-tdep.c: Update return_value hook prototype.
	* sparc-tdep.c: Update return_value hook prototype.
	* sparc64-tdep.c: Update return_value hook prototype.
	* stack.c: Update return_value hook prototype.
	* tic6x-tdep.c: Update return_value hook prototype.
	* tilegx-tdep.c: Update return_value hook prototype.
	* v850-tdep.c: Update return_value hook prototype.
	* valprint.c: Update return_value hook prototype.
	* value.c: Update return_value hook prototype.
	* vax-tdep.c: Update return_value hook prototype.
	* xstormy16-tdep.c: Update return_value hook prototype.
	* xtensa-tdep.c: Update return_value hook prototype.

Enable writing/forging capabilities to memory via the PTRACE_POKECAP ptrace
request.  This patch enables both GDB and gdbserver for Morello.

For remote writes, we use the qXfer:capa:write packet.

gdb/ChangeLog:

2021-03-17  Luis Machado  <luis.machado@arm.com>

	* aarch64-linux-nat.c (aarch64_linux_nat_target)
	<write_capability>: New member function override.
	(aarch64_linux_nat_target::write_capability): New member
	function.
	(maint_print_cap_from_addr_cmd): Adjust printing format.
	(maint_set_capability_in_memory_cmd): New maintenance function.
	(add_show_debug_regs_command): Register new maintenance command.
	* nat/aarch64-cap-linux.c (aarch64_linux_write_capability): New
	function.
	* nat/aarch64-cap-linux.h (aarch64_linux_write_capability): New
	prototype.
	* remote.c (remote_target)
	<write_capability>: New member function override.
	Adjust enum documentation for PACKET_qXfer_capability.
	(remote_target::write_capability): New member function.
	(_initialize_rem...

The tags for PCC/CSP are stored in the order of struct user_morello_state.

Make sure we account for that when extracting the tags.

gdb/ChangeLog:

2021-03-17  Luis Machado  <luis.machado@arm.com>

	* aarch64-tdep.c (aarch64_register_tag): Handle PCC/CSP tag
	extraction.

Disassembling of C64 instructions in GDB does not work correctly. It needs
to pass the proper information to opcodes.

This patch accomplishes that.

gdb/ChangeLog:

2021-03-17  Luis Machado  <luis.machado@arm.com>

	* aarch64-tdep.c (aarch64_find_mapping_symbol, aarch64_pc_is_c64): New
	functions.
	(aarch64_gdb_print_insn): Pass map type to disassembler.

include/ChangeLog:

2021-03-17  Luis Machado  <luis.machado@arm.com>

	* opcode/aarch64.h (enum map_type): Moved from opcodes/aarch64-dis.c.
	Renamed fields.
	(struct aarch64_private_data): New struct.

opcodes/ChangeLog:

2021-03-17  Luis Machado  <luis.machado@arm.com>

	* aarch64-dis.c (enum map_type): Moved to include/opcode/aarch64.h.
	(MAYBE_C64): Adjust.
	(get_sym_code_type): Adjust.
	(print_insn_aarch64): Use private data when available.

Make the Morello register set writable, so GDB can write to the C registers
and forge capabilities.

To enable write access to the registers, the cheri.ptrace_forge_cap sysctl
option must be toggled.

gdb/ChangeLog:

2021-01-15  Luis Machado  <luis.machado@arm.com>

	* aarch64-linux-nat.c (store_cregs_to_thread): Implement.
	(aarch64_linux_nat_target::store_registers): Don't fetch the C
	registers before writing to them.
	Fetch GPR's after modifying the C registers.
	* aarch64-tdep.c (aarch64_cannot_store_register): Remove C registers
	write restriction.
	* regcache.c (regcache_write_pc): Handle partial writes to PCC.

gdbserver/ChangeLog:

2021-01-15  Luis Machado  <luis.machado@arm.com>

	* linux-aarch64-low.cc (aarch64_fill_cregset): New function.
	(aarch64_regsets, aarch64_sve_regsets): Add C registers fill hook.

gdb/ChangeLog:

2021-01-15  Luis Machado  <luis.machado@arm.com>

	* aarch64-linux-tdep.c (aarch64_linux_report_signal_info): Remove
	spurious newline output.

This patch enables capability reads from memory, including the tag bit.

It enables both native GDB and gdbserver to do so.

gdb/ChangeLog:

2021-01-15  Luis Machado  <luis.machado@arm.com>

	* aarch64-linux-nat.c (aarch64_linux_nat_target)
	<read_capability>: New function override.
	(aarch64_linux_nat_target::read_capability): New function.
	(maint_print_cap_from_addr_cmd): New function.
	(add_show_debug_regs_command): Register new maintenance command.
	* aarch64-linux-tdep.c: Include target.h.
	(aarch64_linux_get_cap_tag_from_address): New function.
	(aarch64_linux_init_abi): Register hook for
	gdbarch_get_cap_tag_from_address
	* arch-utils.c (default_get_cap_tag_from_address): New function.
	* arch-utils.h (default_get_cap_tag_from_address): New prototype.
	* configure.nat: Add nat/aarch64-cap-linux.o to the list of object
	files for AArch64-Linux.
	* gdbarch.c: Regenerate.
	* gdbarch.h: Regenerate.
	* gdbarch.sh (get_cap_tag_from_address): New gdbarch hook.
	* nat/aarch64-cap-linux.c: New file.
	* nat/aarch64-cap-linux.h (aarch64_linux_read_capability): New
	prototype.
	* remote.c (remote_target) <read_capability>: New function override.
	(PACKET_qXfer_capability): New enum.
	(remote_target::xfer_partial): Handle TARGET_OBJECT_CAPABILITY.
	(remote_target::read_capability): New member function.
	(_initialize_remote): Add new packet configuration.
	* target-delegates.c: Regenerate.
	* target.c (target_read_capability): New function.
	* target.h (target_object) <TARGET_OBJECT_CAPABILITY>: New enum field.
	(struct target_ops) <read_capability>: New virtual member function.
	(target_read_capability): New prototype.
	* valprint.c (generic_value_print_capability): Handle tags from
	capabilities stored in memory.
	* value.c (value_fetch_lazy_memory): Fetch tag if reading a capability.

gdbserver/ChangeLog

2021-01-15  Luis Machado  <luis.machado@arm.com>

	* configure.srv: Add nat/aarch64-cap-linux.o to the list of object
	files for AArch64-Linux
	* linux-aarch64-low.cc (aarch64_target) <supports_qxfer_capability>
	<qxfer_capability>: New member function overrides.
	(aarch64_target::supports_qxfer_capability): New function.
	(aarch64_target::qxfer_capability): New function.
	* server.cc (handle_qxfer_capability): New function.
	(qxfer_packets): Add "capa" packet.
	* target.cc (process_stratum_target::supports_qxfer_capability)
	(process_stratum_target::qxfer_capability): New functions.
	* target.h (process_stratum_target) <supports_qxfer_capability>
	<qxfer_capability>: New virtual member functions.

This fixes a situation where LR/PC is not available, so we need to throw
an error rather than continuing.

gdb/ChangeLog:

2021-01-15  Luis Machado  <luis.machado@arm.com>

	* aarch64-tdep.c (aarch64_prologue_prev_register)
	(aarch64_dwarf2_prev_register): Throw error if LR is optimized out.

gdb/ChangeLog:

2021-01-15  Luis Machado  <luis.machado@arm.com>

	* Makefile.in (HFILES_NO_SRCDIR): Add nat/aarch64-cap-linux.h.
	* aarch64-linux-nat.c: Include nat/aarch64-cap-linux.h.
	* nat/aarch64-cap-linux.h: New file.
	* nat/aarch64-linux.h (struct user_morello_state): Move to
	nat/aarch64-cap-linux.h.

gdbserver/ChangeLog:

2021-01-15  Luis Machado  <luis.machado@arm.com>

	* linux-aarch64-low.cc: Include nat/aarch64-cap-linux.h.

gdb/ChangeLog:

2021-01-15  Luis Machado  <luis.machado@arm.com>

	* arch/aarch64-cap-linux.h: Fix define name.

gdb/testsuite/ChangeLog:

2021-01-15  Luis Machado  <luis.machado@arm.com>

	* gdb.base/options.exp: Add -compact-capabilities option.

gdb/ChangeLog:

2021-01-15  Luis Machado  <luis.machado@arm.com>

	* aarch64-tdep.c (aarch64_address_class_type_flags_to_name): Return
	NULL.

gdbsupport/ChangeLog:

2021-01-15  Luis Machado  <luis.machado@arm.com>

	capability.cc (capability::to_str): Don't print parenthesis if there
	are no attributes.

Fix some erroneous interpretation of sealed capabilities and adjust the
code to print capability attributes correctly.

gdbsupport/ChangeLog:

2020-12-30  Luis Machado  <luis.machado@arm.com>

	* capability.cc (capability::to_str): Fix compact printing
	format and documentation.
	* capability.h (capability::is_sealed): Fix wrong check.

We just reset the attribute string instead of appending to it.  This patch
fixes this.

gdbsupport/ChangeLog:

2020-12-30  Luis Machado  <luis.machado@arm.com>

	* capability.cc (capability::to_str): Append strings to
	attribute string.

The length used to include the tag, but now it doesn't.  This fixes it.

gdb/ChangeLog:

2020-12-30  Luis Machado  <luis.machado@arm.com>

	* valprint.c (generic_value_print_capability): Don't add 1 to
	the capability length.

Add a new option set/show "print compact-capabilities" that default to "on".

This makes GDB default to printing capabilities in compact format, the CHERI
format.

gdb/ChangeLog:

2020-12-30  Luis Machado  <luis.machado@arm.com>

	* valprint.c (user_print_options): Initialize compact_capabilities.
	(show_print_compact_capabilities): New function.
	(generic_value_print_capability): Use compact_capabilities option.
	(value_print_option_defs): New compact_capabilities option.
	* valprint.h (value_print_options) <compact_capabilities>: New member
	variable.

This patch adds CHERI-style compact printing format to GDB and uses it
by default.

The format is described here: https://github.com/CTSRD-CHERI/cheri-c-programming/wiki/Displaying-Capabilities

gdbsupport/ChangeLog:

2020-12-16  Luis Machado  <luis.machado@arm.com>

	* capability.cc (cap_short_perms_strings): Remove.
	(capability::is_null_derived): New member function.
	(capability::to_str): Document and handle new CHERY-style printing
	format.
	* capability.h (cap_constants): Document the CAP_SEAL_TYPE_*
	constants.
	(struct capability) <is_null_derived>: New member function prototype.

Remove code to return LR for a CLR DWARF register.

For the pure capability ABI, set pc to PCC and sp to CSP.

gdb/ChangeLog:

2020-11-11  Luis Machado  <luis.machado@arm.com>

	* aarch64-tdep.c (aarch64_dwarf_reg_to_regnum): Don't return LR
	for CLR.
	(aarch64_gdbarch_init): Set pc to PCC and sp to CSP for pure cap
	ABI.

Print capability pointers as capabilities, so the user can see the
decoded fields of the capability.

gdb/ChangeLog:

2020-11-11  Luis Machado  <luis.machado@arm.com>

	* c-valprint.c (c_value_print_ptr): Adjust to print capability
	pointers as capabilities.
	(c_value_print_inner): Handle TYPE_CODE_CAPABILITY.
	* findvar.c (extract_integer): Truncate scalars instead of erroring out.
	* valprint.c (generic_value_print_capability): Make non-static and
	print additional space.
	* valprint.h (generic_value_print_capability): New prototype.

In order to produce output that is not so verbose, we print the short version
of the decoded capabilities instead.

gdb/ChangeLog:

2020-11-11  Luis Machado  <luis.machado@arm.com>

	* valprint.c (generic_value_print_capability): Use compact form.

gdbsupport/ChangeLog:

2020-11-11  Luis Machado  <luis.machado@arm.com>

	* capability.cc (cap_short_perms_strings): New static global.
	(capability::to_str): New argument COMPACT. Print contents based
	on the new argument.
	(capability::print): Update calls.
	* capability.h (capability::to_str): Update prototype and
	documentation.

Rename "attributes" to "permissions" when printing decoded capabilities.

gdbsupport/ChangeLog:

2020-11-11  Luis Machado  <luis.machado@arm.com>

	* capability.cc (capability::to_str): Rename "attributes" to
	"permissions".

When casting capabilities and capability pointers to other types, we truncate
the value to the appropriate size, given some capabilities are greater than
8 bytes in size.

gdb/ChangeLog:

2020-11-11  Luis Machado  <luis.machado@arm.com>

	* valops.c (value_cast): Handle casting from capabilities and
	capability pointers.

Support the data_capability and code_capability types, which the capability
counterparts of the data_ptr and code_ptr types.

Adjust the Morello C registers to be of data_capability and code_capability
types.

gdb/ChangeLog:

2020-11-11  Luis Machado  <luis.machado@arm.com>

	* aarch64-tdep.c (aarch64_address_class_type_flags)
	(aarch64_address_class_type_flags_to_name)
	(aarch64_address_class_name_to_type_flags): Use
	TYPE_INSTANCE_FLAG_CAPABILITY instead of
	TYPE_INSTANCE_FLAG_ADDRESS_CLASS_1.
	(aarch64_gdbarch_init): Set capability size to 128.
	* features/aarch64-capability.c: Regenerate.
	* features/aarch64-capability.xml: Update C register types.
	* gdbarch.c: Regenerate.
	* gdbarch.h: Regenerate.
	* gdbarch.sh (code_capability_bit, data_capability)
	(dwarf2_capability_size): Remove.
	* gdbtypes.c (gdbtypes_post_init): Initialize data_capability and
	code_capability types.
	* gdbtypes.h (TYPE_INSTANCE_FLAG_ADDRESS_CLASS_ALL): Include
	TYPE_INSTANCE_FLAG_CAPABILITY in the list of address classes.
	(struct builtin_type) <builtin_data_addr_capability>: Rename to
	builtin_data_capability.
	(struct builtin_type) <builtin_code_addr_capability>: Rename to
	builtin_code_capability.
	* target-descriptions.c (make_gdb_type): Update type names.

gdbsupport/ChangeLog:

2020-11-11  Luis Machado  <luis.machado@arm.com>

	* tdesc.cc (tdesc_predefined_types): Update type names for
	capabilities.

When displaying a capability pointer, don't truncate the length of the type.

Also, update the instance flags to mark capability pointers as
TYPE_INSTANCE_FLAG_CAPABILITY.

gdb/ChangeLog:

2020-11-11  Luis Machado  <luis.machado@arm.com>

	* aarch64-tdep.c (aarch64_address_class_type_flags)
	(aarch64_address_class_type_flags_to_name)
	(aarch64_address_class_name_to_type_flags): Use
	TYPE_INSTANCE_FLAG_CAPABILITY instead of
	TYPE_INSTANCE_FLAG_ADDRESS_CLASS_1.
	* gdbtypes.h (TYPE_INSTANCE_FLAG_ADDRESS_CLASS_ALL): Include
	TYPE_INSTANCE_FLAG_CAPABILITY.
	* printcmd.c (print_scalar_formatted): Don't truncate capability
	pointers.

This change makes the code more straightforward, since we can expect the order
of the X registers to match that of the C registers.  That way we don't have to
deal with ordering issues.

It also simplifies the access to the dynamic C register numbers through the
gdbarch tdep data structure.

gdb/ChangeLog:

2020-11-11  Luis Machado  <luis.machado@arm.com>

	* aarch64-linux-nat.c (fetch_cregs_from_thread): Invert pcc/csp
	order.
	* aarch64-linux-tdep.c (aarch64_linux_sigframe_init): Likewise.
	* aarch64-tdep.c (aarch64_c_register_names): Likewise.
	(aarch64_analyze_prologue): Remove code to handle csp/pcc ordering
	issues.
	(aarch64_prologue_prev_register): Use new tdep fields.
	(aarch64_dwarf2_prev_register): Use new tdep fields and handle lr/clr.
	(aarch64_dwarf2_frame_init_reg): Use new tdep fields.
	(aarch64_gdbarch_init): Initialize the new tdep fields.
	* aarch64-tdep.h (gdbarch_tdep) <cap_reg_clr, cap_reg_csp>
	<cap_reg_pcc, cap_reg_rcsp>: New fields
	* features/aarch64-capability.c: Regenerate.
	* features/aarch64-capability.xml: Invert pcc/csp.

gdbserver/ChangeLog:

2020-11-11  Luis Machado  <luis.machado@arm.com>

	* linux-aarch64-low.cc (aarch64_store_cregset): Invert pcc/csp.

Make sure we only use the C registers if they have been detected.

gdb/ChangeLog:

2020-11-11  Luis Machado  <luis.machado@arm.com>

	* aarch64-tdep.c (aarch64_prologue_prev_register): Guard use of
	C registers.
	(aarch64_dwarf2_prev_register): Likewise.
	(aarch64_dwarf2_frame_init_reg): Likewise.
	* aarch64-linux-nat.c
	(aarch64_linux_nat_target::store_registers): Likewise.

Add the proper iclass to add/sub so code relying on instruction
decoding can extract precise information.

opcodes/ChangeLog:

2020-10-20  Luis Machado  <luis.machado@arm.com>

	* aarch64-tbl.h (aarch64_opcode_table): Update iclass field
	for add/sub

Add the register set that is going to be used to read core file data.

gdb/ChangeLog:

2020-10-20  Luis Machado  <luis.machado@arm.com>

	* aarch64-linux-tdep.c (aarch64_linux_cregmap)
	(aarch64_linux_cregset): New structs.
	(aarch64_linux_iterate_over_regset_sections): Check for capability
	registers.
	(aarch64_linux_init_abi): Initialize C register set numbers.

Given the use of C registers implies we now have to store 16 bytes worth of
data instead of 8 bytes, we need to adjust the code that handles tracking
register motion and register saving to the stack.

FIXME-Morello: This patch requires changes to opcodes/aarch64-tbl.h so the
a64c instructions carry the proper iclass and opcode information.

Right now, some of the a64c instructions don't carry enough information for
the prologue analyzer to distinguish/group them.

This patch also adds more debugging output.

gdb/ChangeLog:

2020-10-20  Luis Machado  <luis.machado@arm.com>

	* aarch64-tdep.c (aarch64_analyze_prologue): Handle C registers and
	a64c instructions.
	(aarch64_scan_prologue): Add debugging output.
	* prologue-value.c (pv_area::find_reg): Don't match the register size
	exactly, but check if the area size is at least the size of a register.

This patch teaches GDB how to handle restoring CLR and PCC values properly.

gdb/ChangeLog:

2020-10-20  Luis Machado  <luis.machado@arm.com>

	* aarch64-tdep.c (aarch64_prologue_prev_register): Use LR or CLR
	depending on the request.
	(aarch64_dwarf_reg_to_regnum): Redirect CLR to LR temporarily.
	* aarch64-tdep.h (AARCH64_DWARF_CLR): New constant.

Adjust unwinding functions to cope with the presence of C registers.

gdb/ChangeLog:

2020-10-20  Luis Machado  <luis.machado@arm.com>

	* aarch64-tdep.c (aarch64_prologue_prev_register): Handle the PCC and
	CSP registers. Remove the LSB.
	(aarch64_dwarf2_prev_register): Handle CSP, PCC and remove the LSB
	from CLR.
	(aarch64_dwarf2_frame_init_reg): Handle PCC and CSP.
	(aarch64_dwarf_reg_to_regnum): Handle C registers.

Handle the Morello 'C' augmentation character. It is not used yet, but it
is acknowledged.

gdb/ChangeLog:

2020-10-20  Luis Machado  <luis.machado@arm.com>

	* dwarf2/frame.c (struct dwarf2_cie) <pure_cap>: New field.
	(decode_frame_entry_1): Handle the 'C' augmentation character.

This patch teaches GDB how to print the capability tag from registers.

gdb/ChangeLog:

2020-10-20  Luis Machado  <luis.machado@arm.com>

	* aarch64-tdep.c (aarch64_register_has_tag, aarch64_register_tag): New
	functions.
	(aarch64_gdbarch_init): Register hooks.
	* arch-utils.c (default_register_has_tag, default_register_tag): New
	functions.
	* arch-utils.h (default_register_has_tag, default_register_tag): New
	prototypes.
	* gdbarch.c: Regenerate.
	* gdbarch.h: Likewise.
	* gdbarch.sh (register_has_tag, register_tag): New gdbarch hooks.
	* regcache.c (readable_regcache::cooked_read_value): Fetch the tag
	metadata from registers.
	* valprint.c (generic_value_print_capability): Display register tags.
	* value.c (struct value) <tagged, tag>: New fields.
	(value_contents_copy_raw): Handle tags.
	(value_tagged, set_value_tagged, value_tag, set_value_tag): New
	functions.
	(value_copy): Handle tags.
	* value.h (value_tagged, set_value_tagged, value_tag)
	(set_value_tag): New prototypes.

This patch teaches GDB about AArch64 mapping symbols and special minimal
symbols.

FIXME-Morello: This is currently not actively used, but will be used to detect
capability mode functions later.

gdb/ChangeLog:

2020-10-20  Luis Machado  <luis.machado@arm.com>

	* aarch64-tdep.c: Include elf-bfd.h.
	(MSYMBOL_SET_SPECIAL, MSYMBOL_IS_SPECIAL): New constants.
	(aarch64_mapping_symbol): New struct.
	(aarch64_mapping_symbol_vec): New typedef.
	(aarch64_per_bfd): New struct.
	(aarch64_bfd_data_key): New static global.
	(aarch64_elf_make_msymbol_special, +aarch64_record_special_symbol): New
	function.
	(aarch64_gdbarch_init): Register hooks.

This patch attempts to detect if we are loading a capability-enabled symbol
file or not, so we can set the proper hooks.

FIXME-Morello: This still needs formalization in the ABI document.

gdb/ChangeLog:

2020-10-20  Luis Machado  <luis.machado@arm.com>

	* aarch64-tdep.c (aarch64_bfd_has_capabilities): New function.
	(aarch64_gdbarch_init): Do static ABI check.

This patch adds cfp, clr, c31, cip0 and cip1, aliased to c29, c30, c31, c16 and
c17.

gdb/ChangeLog:

2020-10-20  Luis Machado  <luis.machado@arm.com>

	* aarch64-tdep.c (aarch64_morello_register_aliases): New static global.
	(aarch64_gdbarch_init): Initialize alias registers.

Morello can't support displaced stepping at the moment given it has no API
to write capabilities, which is needed when GDB needs to adjust the X and C
registers during a displaced stepping operation.

gdb/ChangeLog:

2020-10-20  Luis Machado  <luis.machado@arm.com>

	* aarch64-linux-tdep.c (aarch64_linux_init_abi): Only set displaced
	stepping hooks for non-Morello targets.