This patch teaches GDBServer how to software single step on ARM
linux by sharing code with GDB.
The arm_get_next_pcs function in GDB is now shared with GDBServer. So
that GDBServer can use the function to return the possible addresses of
the next PC.
A proper shared context was also needed so that we could share the code,
this context is described in the arm_get_next_pcs structure.
Testing :
No regressions, tested on ubuntu 14.04 ARMv7 and x86.
With gdbserver-{native,extended} / { -marm -mthumb }
gdb/ChangeLog:
* Makefile.in (ALL_TARGET_OBS): Append arm-get-next-pcs.o,
arm-linux.o.
(ALLDEPFILES): Append arm-get-next-pcs.c, arm-linux.c
(arm-linux.o): New rule.
(arm-get-next-pcs.o): New rule.
* arch/arm-get-next-pcs.c: New file.
* arch/arm-get-next-pcs.h: New file.
* arch/arm-linux.h: New file.
* arch/arm-linux.c: New file.
* arm.c: Include common-regcache.c.
(thumb_advance_itstate): Moved from arm-tdep.c.
(arm_instruction_changes_pc): Likewise.
(thumb_instruction_changes_pc): Likewise.
(thumb2_instruction_changes_pc): Likewise.
(shifted_reg_val): Likewise.
* arm.h (submask): Move macro from arm-tdep.h
(bit): Likewise.
(bits): Likewise.
(sbits): Likewise.
(BranchDest): Likewise.
(thumb_advance_itstate): Moved declaration from arm-tdep.h
(arm_instruction_changes_pc): Likewise.
(thumb_instruction_changes_pc): Likewise.
(thumb2_instruction_changes_pc): Likewise.
(shifted_reg_val): Likewise.
* arm-linux-tdep.c: Include arch/arm.h, arch/arm-get-next-pcs.h
arch/arm-linux.h.
(arm_linux_get_next_pcs_ops): New struct.
(ARM_SIGCONTEXT_R0, ARM_UCONTEXT_SIGCONTEXT,
ARM_OLD_RT_SIGFRAME_SIGINFO, ARM_OLD_RT_SIGFRAME_UCONTEXT,
ARM_NEW_RT_SIGFRAME_UCONTEXT, ARM_NEW_SIGFRAME_MAGIC): Move stack
layout defines to arch/arm-linux.h.
(arm_linux_sigreturn_next_pc_offset): Move to arch/arm-linux.c.
(arm_linux_software_single_step): Adjust for arm_get_next_pcs
implementation.
* arm-tdep.c: Include arch/arm-get-next-pcs.h.
(arm_get_next_pcs_ops): New struct.
(submask): Move macro to arm.h.
(bit): Likewise.
(bits): Likewise.
(sbits): Likewise.
(BranchDest): Likewise.
(thumb_instruction_changes_pc): Move to arm.c
(thumb2_instruction_changes_pc): Likewise.
(arm_instruction_changes_pc): Likewise.
(shifted_reg_val): Likewise.
(thumb_advance_itstate): Likewise.
(thumb_get_next_pc_raw): Move to arm-get-next-pcs.c.
(arm_get_next_pc_raw): Likewise.
(arm_get_next_pc): Likewise.
(thumb_deal_with_atomic_sequence_raw): Likewise.
(arm_deal_with_atomic_sequence_raw): Likewise.
(arm_deal_with_atomic_sequence): Likewise.
(arm_get_next_pcs_read_memory_unsigned_integer): New function.
(arm_get_next_pcs_addr_bits_remove): Likewise.
(arm_get_next_pcs_syscall_next_pc): Likewise.
(arm_get_next_pcs_is_thumb): Likewise.
(arm_software_single_step): Adjust for arm_get_next_pcs
implementation.
* arm-tdep.h: (arm_get_next_pc): Remove declaration.
(arm_get_next_pcs_read_memory_unsigned_integer):
New declaration.
(arm_get_next_pcs_addr_bits_remove): Likewise.
(arm_get_next_pcs_syscall_next_pc): Likewise.
(arm_get_next_pcs_is_thumb): Likewise.
(arm_deal_with_atomic_sequence: Remove declaration.
* common/gdb_vecs.h: Add CORE_ADDR vector definition.
* configure.tgt (aarch64*-*-linux): Add arm-get-next-pcs.o,
arm-linux.o.
(arm*-wince-pe): Add arm-get-next-pcs.o.
(arm*-*-linux*): Add arm-get-next-pcs.o, arm-linux.o,
arm-get-next-pcs.o
(arm*-*-netbsd*,arm*-*-knetbsd*-gnu): Add arm-get-next-pcs.o.
(arm*-*-openbsd*): Likewise.
(arm*-*-symbianelf*): Likewise.
(arm*-*-*): Likewise.
* symtab.h: Move CORE_ADDR vector definition to gdb_vecs.h.
gdb/gdbserver/ChangeLog:
* Makefile.in (SFILES): Append arch/arm-linux.c,
arch/arm-get-next-pcs.c.
(arm-linux.o): New rule.
(arm-get-next-pcs.o): New rule.
* configure.srv (arm*-*-linux*): Add arm-get-next-pcs.o,
arm-linux.o.
* linux-aarch32-low.c (arm_abi_breakpoint): Remove macro. Moved
to linux-aarch32-low.c.
(arm_eabi_breakpoint, arm_breakpoint): Likewise.
(arm_breakpoint_len, thumb_breakpoint): Likewise.
(thumb_breakpoint_len, thumb2_breakpoint): Likewise.
(thumb2_breakpoint_len): Likewise.
(arm_is_thumb_mode): Make non-static.
* linux-aarch32-low.h (arm_abi_breakpoint): New macro. Moved
from linux-aarch32-low.c.
(arm_eabi_breakpoint, arm_breakpoint): Likewise.
(arm_breakpoint_len, thumb_breakpoint): Likewise.
(thumb_breakpoint_len, thumb2_breakpoint): Likewise.
(thumb2_breakpoint_len): Likewise.
(arm_is_thumb_mode): New declaration.
* linux-arm-low.c: Include arch/arm-linux.h
aarch/arm-get-next-pcs.h, sys/syscall.h.
(get_next_pcs_ops): New struct.
(get_next_pcs_addr_bits_remove): New function.
(get_next_pcs_is_thumb): New function.
(get_next_pcs_read_memory_unsigned_integer): Likewise.
(arm_sigreturn_next_pc): Likewise.
(get_next_pcs_syscall_next_pc): Likewise.
(arm_gdbserver_get_next_pcs): Likewise.
(struct linux_target_ops) <arm_gdbserver_get_next_pcs>:
Initialize.
* linux-low.h: Move CORE_ADDR vector definition to gdb_vecs.h.
* server.h: Include gdb_vecs.h.
This patch is in preparation for software single step support on ARM in
GDBServer. It refactors arm_*_software_single_step and sub-functions to
use regcache instead of frame to access registers so that the code can be
shared more easily between GDB and GDBServer.
Note also that since the intention is at some point to get rid of frame
completely in that function, memory reads have also been replaced by
read_memory_unsigned_integer rather than get_frame_memory_unsigned.
No regressions, tested on ubuntu 14.04 ARMv7 and x86.
With gdbserver-{native,extended} / { -marm -mthumb }
gdb/ChangeLog:
* arm-linux-tdep.c (arm_linux_sigreturn_next_pc_offset): New function.
(arm_linux_sigreturn_next_pc): Likewise.
(arm_linux_syscall_next_pc): Use regcache instead of frame.
(arm_linux_software_single_step): Likewise.
* arm-tdep.c (arm_is_thumb): New function.
(shifted_reg_va): Use regcache instead of frame.
(thumb_get_next_pc_raw): Likewise.
(arm_get_next_pc_raw): Likewise.
(arm_get_next_pc): Likewise.
(thumb_deal_with_atomic_sequence_raw): Likewise.
(arm_deal_with_atomic_sequence_raw): Likewise.
(arm_deal_with_atomic_sequence): Likewise.
(arm_software_single_step): Likewise.
* arm-tdep.h (struct gdbarch_tdep): Use regcache for syscall_next_pc.
(arm_get_next_pc): Use regcache.
(arm_deal_with_atomic_sequence): Likewise.
(arm_is_thumb): New declaration.
* regcache.c (regcache_raw_get_unsigned): New function.
* regcache.h (regcache_raw_get_unsigned): New function declaration.
This patch is in preparation for software single stepping support on ARM
it shares some functions and definitions that will be needed.
No regressions, tested on ubuntu 14.04 ARMv7 and x86.
With gdbserver-{native,extended} / { -marm -mthumb }
Not tested: wince/bsd build.
gdb/ChangeLog:
* arch/arm.c (bitcount): Move from arm-tdep.c.
(condition_true): Likewise.
* arch/arm.h (Instruction Definitions): Move form arm-tdep.h.
(condition_true): Move defenition from arm-tdep.h.
(bitcount): Likewise.
* arm-tdep.c (condition_true): Move to arch/arm.c.
(bitcount): Likewise.
* arm-tdep.h (Instruction Definitions): Move to arch/arm.h.
* arm-wince-tdep.c: Include arch/arm.h.
* armnbsd-tdep.c: Likewise.
This patch moves ARM register numbers enum to arch/arm.h, so that it
can used by GDBserver too.
This patch also creates a new directory gdb/arch in which arch-specific
or target-specific files are placed.
gdb:
2015-07-30 Yao Qi <yao.qi@linaro.org>
* arm-tdep.h (enum gdb_regnum): Move it to ...
* arch/arm.h: ... here. New file.
* Makefile.in (HFILES_NO_SRCDIR): Add arch/arm.h.
This patch is to remove the global variable arm_linux_has_wmmx_registers
in arm-linux-nat.c, and add a new field have_wmmx_registers in
'struct gdbarch_tdep'.
gdb:
2015-05-28 Yao Qi <yao.qi@linaro.org>
* arm-linux-nat.c (arm_linux_has_wmmx_registers): Remove.
(arm_linux_fetch_inferior_registers): Use
tdep->have_wmmx_registers instead of arm_linux_has_wmmx_registers.
(arm_linux_store_inferior_registers): Likewise.
(arm_linux_read_description): Don't set
arm_linux_has_wmmx_registers.
* arm-tdep.c (arm_gdbarch_init): Set
tdep->have_wmmx_registers according target descriptions.
* arm-tdep.h (struct gdbarch_tdep) <have_wmmx_registers>: New
field.
This patch is to remove the global variable arm_linux_vfp_register_count
from arm-linux-nat.c. This global variable is set when native gdb
looks for the right target description according HWCAP. However,
'struct gdbarch_tdep' has already had a field have_vfp_registers, which
is a boolean about whether target has vfp registers or not. This
patch converts this boolean field to a numeric counter to replace
global variable arm_linux_vfp_register_count.
gdb:
2015-05-28 Yao Qi <yao.qi@linaro.org>
* arm-linux-nat.c (arm_linux_vfp_register_count): Remove.
(fetch_vfp_regs): Use vfp_register_count from gdbarch_tdep
instead of arm_linux_vfp_register_count.
(store_vfp_regs): Likewise.
(arm_linux_fetch_inferior_registers): Likewise.
(arm_linux_store_inferior_registers): Likewise.
(arm_linux_read_description): Don't set
arm_linux_vfp_register_count.
* arm-linux-tdep.c (arm_linux_iterate_over_regset_sections):
Adjust.
* arm-tdep.c (arm_gdbarch_init): Add assert on
vfp_register_count.
* arm-tdep.h (struct gdbarch_tdep) <have_vfp_registers>: Rename
field to vfp_register_count. All users updated.
-Wpointer-sign catches all these cases across the codebase that should
be using gdb_byte for raw target bytes. I think these are all
obvious, hence I've collapsed into a single patch.
gdb/
2013-04-19 Pedro Alves <palves@redhat.com>
* aarch64-tdep.c (aarch64_default_breakpoint): Change type to
gdb_byte[].
(aarch64_breakpoint_from_pc): Change return type to gdb_byte *.
* ada-lang.c (ada_value_assign): Use gdb_byte.
* alphanbsd-tdep.c (sigtramp_retcode): Change type to gdb_byte[].
(alphanbsd_sigtramp_offset): Use gdb_byte.
* arm-linux-tdep.c (arm_linux_arm_le_breakpoint)
(arm_linux_arm_be_breakpoint, eabi_linux_arm_le_breakpoint)
(eabi_linux_arm_be_breakpoint, arm_linux_thumb_be_breakpoint)
(arm_linux_thumb_le_breakpoint, arm_linux_thumb2_be_breakpoint)
(arm_linux_thumb2_le_breakpoint): Change type to gdb_byte[].
* arm-tdep.c (arm_stub_unwind_sniffer)
(arm_displaced_init_closure): Use gdb_byte.
(arm_default_arm_le_breakpoint, arm_default_arm_be_breakpoint)
(arm_default_thumb_le_breakpoint)
(arm_default_thumb_be_breakpoint): Change type to gdb_byte[].
* arm-tdep.h (struct gdbarch_tdep) <arm_breakpoint,
thumb_breakpoint, thumb2_breakpoint>: Change type to gdb_byte *.
* arm-wince-tdep.c (arm_wince_le_breakpoint)
(arm_wince_thumb_le_breakpoint): Change type to gdb_byte[].
* armnbsd-tdep.c (arm_nbsd_arm_le_breakpoint)
(arm_nbsd_arm_be_breakpoint, arm_nbsd_thumb_le_breakpoint)
(arm_nbsd_thumb_be_breakpoint): Change type to gdb_byte[].
* armobsd-tdep.c (arm_obsd_thumb_le_breakpoint)
(arm_obsd_thumb_be_breakpoint): Change type to gdb_byte[].
* cris-tdep.c (push_stack_item, cris_push_dummy_call)
(cris_store_return_value, cris_extract_return_value): Use
gdb_byte.
(constraint): Change type of parameter to char * from signed
char*. Use gdb_byte.
* dwarf2loc.c (read_pieced_value, write_pieced_value): Change type
of local buffer to gdb_byte *.
* dwarf2read.c (read_index_from_section): Use gdb_byte.
(create_dwp_hash_table): Change type of locals to gdb_byte *.
(add_address_entry): Change type of local buffer to gdb_byte[].
* frv-tdep.c (frv_adjust_breakpoint_address, find_func_descr)
(frv_push_dummy_call): Use gdb_byte.
* hppa-hpux-tdep.c (hppa_hpux_push_dummy_code)
(hppa_hpux_supply_ss_fpblock, hppa_hpux_supply_ss_wide)
(hppa_hpux_supply_save_state): Use gdb_byte.
* hppa-tdep.c (hppa32_push_dummy_call)
(hppa64_convert_code_addr_to_fptr): Use gdb_byte.
* ia64-tdep.c (extract_bit_field, replace_bit_field)
(slotN_contents, replace_slotN_contents): Change type of parameter
to gdb_byte *.
(fetch_instruction, ia64_pseudo_register_write)
(ia64_register_to_value, ia64_value_to_register)
(ia64_extract_return_value, ia64_store_return_value)
(ia64_push_dummy_call): Use gdb_byte.
* m32c-tdep.c (m32c_return_value): Remove cast.
* m68hc11-tdep.c (m68hc11_pseudo_register_write)
(m68hc11_push_dummy_call, m68hc11_store_return_value): Use
gdb_byte.
* mipsnbsd-tdep.c (mipsnbsd_get_longjmp_target): Use gdb_byte.
* mn10300-tdep.c (mn10300_store_return_value)
(mn10300_breakpoint_from_pc, mn10300_push_dummy_call): Use
gdb_byte.
* moxie-tdep.c (moxie_process_readu): Use gdb_byte.
(moxie_process_record): Remove casts.
* ppc-ravenscar-thread.c (supply_register_at_address)
(ppc_ravenscar_generic_store_registers): Use gdb_byte.
* ravenscar-thread.c (get_running_thread_id): Use gdb_byte.
* remote-m32r-sdi.c (m32r_fetch_register): Use gdb_byte.
* remote-mips.c (mips_xfer_memory): Use gdb_byte.
* remote.c (compare_sections_command): Use gdb_byte.
* score-tdep.c (score7_free_memblock): Change type of parameter to
gdb_byte *.
* sh-tdep.c (sh_justify_value_in_reg): Change return type to
gdb_byte *. Use gdb_byte.
(sh_push_dummy_call_fpu): Use gdb_byte.
(sh_extract_return_value_nofpu, sh_extract_return_value_fpu)
(sh_store_return_value_nofpu, sh_store_return_value_fpu)
(sh_register_convert_to_virtual, sh_register_convert_to_raw):
Change parameter type to 'gdb_byte *'. Use gdb_byte.
(sh_pseudo_register_read, sh_pseudo_register_write): Use gdb_byte.
* sh64-tdep.c (sh64_push_dummy_call): Use gdb_byte.
(sh64_store_return_value, sh64_register_convert_to_virtual):
Change parameter type to 'gdb_byte *'. Use gdb_byte.
(sh64_pseudo_register_write): Use gdb_byte.
* solib-darwin.c (darwin_current_sos): Add casts to 'gdb_byte *'.
* solib-irix.c (fetch_lm_info): Likewise. Use gdb_byte for byte
buffer.
(irix_current_sos): Use gdb_byte.
* solib-som.c (som_current_sos): Use gdb_byte.
* sparc-ravenscar-thread.c (supply_register_at_address)
(sparc_ravenscar_generic_store_registers): Use gdb_byte.
* spu-multiarch.c (spu_xfer_partial): Add cast to 'char *'.
* spu-tdep.c (spu_get_overlay_table): Use gdb_byte.
* tic6x-tdep.c (tic6x_breakpoint_from_pc): Change return type to
'gdb_byte *'.
* tic6x-tdep.h (struct gdbarch_tdep) <breakpoint>: Change type to
'gdb_byte *'.
* tracepoint.c (tfile_fetch_registers): Use gdb_byte.
* xstormy16-tdep.c (xstormy16_extract_return_value)
(xstormy16_store_return_value): Change parameter type to
'gdb_byte *'. Adjust.
(xstormy16_push_dummy_call): Use gdb_byte.
* xtensa-tdep.c (xtensa_scan_prologue, call0_ret)
(call0_analyze_prologue, execute_code): Use gdb_byte.
Two modifications:
1. The addition of 2013 to the copyright year range for every file;
2. The use of a single year range, instead of potentially multiple
year ranges, as approved by the FSF.
set_gdbarch_process_record.
Initialize `arm_swi_record' field.
* arm-tdep.c (arm_process_record): New function.
(deallocate_reg_mem): New function.
(decode_insn): New function.
(thumb_record_branch): New function.
(thumb_record_ldm_stm_swi(): New function.
(thumb_record_misc): New function.
(thumb_record_ld_st_stack): New function.
(thumb_record_ld_st_imm_offset): New function.
(thumb_record_ld_st_reg_offset(): New function.
(thumb_record_add_sub_cmp_mov): New function.
(thumb_record_shift_add_sub): New function.
(arm_record_coproc_data_proc): New function.
(arm_record_coproc): New function.
(arm_record_b_bl): New function.
(arm_record_ld_st_multiple): New function.
(arm_record_ld_st_reg_offset): New function.
(arm_record_ld_st_imm_offset): New function.
(arm_record_data_proc_imm): New function.
(arm_record_data_proc_misc_ld_str): New function.
(arm_record_extension_space): New function.
(arm_record_strx): New function.
(sbo_sbz): New function.
(struct insn_decode_record): New structure for arm insn record.
(REG_ALLOC): New macro for reg allocations.
(MEM_ALLOC): New macro for memory allocations.
* arm-tdep.h (struct gdbarch_tdep): New field 'arm_swi_record'
* arm-tdep.h (struct displaced_step_closure): Add two new fields
is_thumb and insn_size.
* arm-tdep.c (displaced_read_reg): Adjust correct pipeline offset
on both ARM and Thumb mode.
(arm_process_displaced_insn): Set is_thumb and insn_size.
(arm_displaced_init_closure): Handle both 16-bit and 32-bit.
(arm_displaced_step_fixup): Likewise.
(arm_linux_restart_syscall_init): Handle both on-stack and in-kernel
versions of the trampoline. Handle Thumb vs. ARM addresses.
(arm_kernel_linux_restart_syscall_tramp_frame): New global.
(arm_linux_init_abi): Install it.
* arm-tdep.c (arm_psr_thumb_bit): Make global.
* arm-tdep.c (arm_psr_thumb_bit): Add prototype.
* arm-linux-tdep.c (arm_linux_sigreturn_return_addr): New.
(arm_linux_syscall_next_pc): New.
(arm_linux_copy_svc): Use arm_linux_sigreturn_return_addr instead.
(arm_linux_init_abi): Initialize syscall_next_pc.
* arm-tdep.c (thumb_get_next_pc_raw): Get next pc of SWI in Thumb mode.
(arm_get_next_pc_raw): Get next pc of SWI in ARM mode.
* arm-tdep.h (struct gdbarch_tdep): Add a function pointer syscall_next_pc.
Declare arm_frame_is_thumb.
(arm_psr_thumb_bit): New. Update all uses of CPSR_T to
call this function.
(arm_pc_is_thumb): Add a gdbarch argument. Update all callers.
Check is_m after force-mode.
(arm_gdbarch_init): Check the binary before the target description.
Add check for M profile attribute. If we have an M-profile device,
but no target register description, use arm-with-m. Recognize the
new org.gnu.gdb.arm.m-profile feature and its xpsr register.
(_initialize_arm_tdep): Call initialize_tdesc_arm_with_m.
* arm-tdep.h (XPSR_T): Define.
(struct gdbarch_tdep): Add is_m member.
* features/arm-m-profile.xml, features/arm-with-m.c,
features/arm-with-m.xml: New files.
doc/
* gdb.texinfo (ARM Features): Document
org.gnu.gdb.arm.m-profile.
* arm-tdep.h (gdb_regnum): Add ARM_FPSCR_REGNUM
* arm-linux-nat.c (arm_linux_vfp_register_count): New
variable.
(fetch_vfp_registers): New function to fetch VFP registers.
(store_vfp_registers): New function to store VFP registers.
(arm_linux_fetch_inferior_registers): Add support for VFP
registers.
(arm_linux_store_inferior_registers): Likewise.
(arm_linux_read_description): Likewise.
(_initialize_arm_linux_nat): Delay initialising iWMMX tdesc
until we need it.
(arm_linux_thumb2_le_breakpoint): New constants.
(arm_linux_init_abi): Set thumb2_breakpoint and
thumb2_breakpoint_size.
* arm-tdep.c (thumb_insn_size, thumb_advance_itstate): New functions.
(thumb_get_next_pc): Add a comment. Rename IT to ITSTATE.
Implement support for single stepping through IT blocks if
a 32-bit Thumb breakpoint instruction is available.
(arm_breakpoint_from_pc): If a 32-bit Thumb breakpoint instruction
is available, use it when needed.
(arm_remote_breakpoint_from_pc): New function.
(arm_gdbarch_init): Register arm_remote_breakpoint_from_pc.
* arm-tdep.h (struct gdbarch_tdep): Correct thumb_breakpoint
comment. Add thumb2_breakpoint and thumb2_breakpoint_size.
gdbserver/
* linux-arm-low.c (thumb_breakpoint_len): Delete.
(thumb2_breakpoint): New.
(arm_breakpoint_at): Check for Thumb-2 breakpoints.
testsuite/
* gdb.arch/thumb2-it.S, gdb.arch/thumb2-it.exp: New files.
* arm-tdep.c (arm_frame_is_thumb): New.
(arm_pc_is_thumb): Clarify comment.
(thumb_analyze_prologue): Remove PC special case.
(thumb_scan_prologue): Take a block_addr argument. Use it for
find_pc_partial_function. Remove unused variables.
(arm_scan_prologue): Use arm_frame_is_thumb. Use the block address
for find_pc_partial_function. Remove PC special case.
(arm_prologue_prev_register): Add special handling for PC and CPSR.
(arm_dwarf2_prev_register, arm_dwarf2_frame_init_reg): New.
(arm_get_next_pc): Use arm_frame_is_thumb.
(arm_write_pc): Use CPSR_T instead of 0x20.
(arm_gdbarch_init): Call dwarf2_frame_set_init_reg.
* arm-tdep.h (enum gdb_regnum): Add ARM_CPSR_REGNUM.
(CPSR_T): Define.
* dwarf2-frame.c (dwarf2_frame_prev_register): Handle
DWARF2_FRAME_REG_FN.
* dwarf2-frame.h (enum dwarf2_frame_reg_rule): Add
DWARF2_FRAME_REG_FN.
(struct dwarf2_frame_state_reg): Add FN to loc union.
* gdb.arch/thumb-prologue.exp: Do not expect a saved PC.
* arm-tdep.c (arm_prologue_this_id): Replace LOWEST_PC by its
expression and use get_frame_arch to replace current_gdbarch by frame's
architecture.
*arm-tdep.h (LOWEST_PC): Remove
(thumb_analyze_prologue): Move pv_area_store_would_trash call
out of loop. Do not set cache->frameoffset.
(arm_scan_prologue): Use prologue-value mechanism. Do not set
frameoffset. Simplify framesize.
(arm_make_prologue_cache, arm_normal_frame_base): Do not use
frameoffset.
* arm-tdep.h (enum gdb_regnum): Add ARM_IP_REGNUM.
