Re: [PATCH] [ARM] Remove field syscall_next_pc in struct gdbarch_tdep

Antoine Tremblay
2016-01-13T19:20:45Z

On 01/13/2016 11:53 AM, Yao Qi wrote:
> Field syscall_next_pc in struct gdbarch_tdep was to calculate the
> next pc of syscall instruction. On linux target, syscall_next_pc
> is set to arm_linux_syscall_next_pc, to do linux specific things.
> However, after we have struct arm_get_next_pcs_ops, we can do the
> same thing in struct arm_get_next_pcs_ops field syscall_next_pc,
> so syscall_next_pc in struct gdbarch_tdep is not needed any more.
>
> No regressions on arm-linux.
>
> gdb:
>
> 2016-01-13 Yao Qi <yao.qi@linaro.org>
>
> * arm-linux-tdep.c (arm_linux_get_next_pcs_syscall_next_pc):
> Declare.
> (arm_linux_get_next_pcs_ops): Install
> arm_linux_get_next_pcs_syscall_next_pc.
> (arm_linux_syscall_next_pc): Change to ...
> (arm_linux_get_next_pcs_syscall_next_pc): ... it.
> (arm_linux_init_abi): Don't set tdep->syscall_next_pc.
> * arm-tdep.c (arm_get_next_pcs_syscall_next_pc): Declare.
> (arm_get_next_pcs_syscall_next_pc): Make it static. Don't
> call tdep->syscall_next_pc.
> * arm-tdep.h (struct gdbarch_tdep) <syscall_next_pc>: Remove.
> (arm_get_next_pcs_syscall_next_pc): Remove.
> ---
> gdb/arm-linux-tdep.c | 27 +++++++++++++--------------
> gdb/arm-tdep.c | 16 ++++++++--------
> gdb/arm-tdep.h | 7 -------
> 3 files changed, 21 insertions(+), 29 deletions(-)
>
> diff --git a/gdb/arm-linux-tdep.c b/gdb/arm-linux-tdep.c
> index 6050bdf..2306bda 100644
> --- a/gdb/arm-linux-tdep.c
> +++ b/gdb/arm-linux-tdep.c
> @@ -265,10 +265,14 @@ static const gdb_byte arm_linux_thumb2_le_breakpoint[] = { 0xf0, 0xf7, 0x00, 0xa
> /* Syscall number for rt_sigreturn. */
> #define ARM_RT_SIGRETURN 173
>
> +static CORE_ADDR
> + arm_linux_get_next_pcs_syscall_next_pc (struct arm_get_next_pcs *self,
> + CORE_ADDR pc);
> +

Indent looks wrong on function signature line.

> /* Operation function pointers for get_next_pcs. */
> static struct arm_get_next_pcs_ops arm_linux_get_next_pcs_ops = {
> arm_get_next_pcs_read_memory_unsigned_integer,
> - arm_get_next_pcs_syscall_next_pc,
> + arm_linux_get_next_pcs_syscall_next_pc,
> arm_get_next_pcs_addr_bits_remove,
> arm_get_next_pcs_is_thumb
> };
> @@ -859,26 +863,23 @@ arm_linux_get_syscall_number (struct gdbarch *gdbarch,
> return svc_number;
> }
>
> -/* When the processor is at a syscall instruction, return the PC of the
> - next instruction to be executed. */
> -
> static CORE_ADDR
> -arm_linux_syscall_next_pc (struct regcache *regcache)
> +arm_linux_get_next_pcs_syscall_next_pc (struct arm_get_next_pcs *self,
> + CORE_ADDR pc)
> {
> - CORE_ADDR pc = regcache_read_pc (regcache);
> CORE_ADDR next_pc = 0;
> - int is_thumb = arm_is_thumb (regcache);
> + int is_thumb = arm_is_thumb (self->regcache);
> ULONGEST svc_number = 0;
> - struct gdbarch *gdbarch = get_regcache_arch (regcache);
> + struct gdbarch *gdbarch = get_regcache_arch (self->regcache);
>
> if (is_thumb)
> {
> - svc_number = regcache_raw_get_unsigned (regcache, 7);
> + svc_number = regcache_raw_get_unsigned (self->regcache, 7);
> next_pc = pc + 2;
> }
> else
> {
> - struct gdbarch *gdbarch = get_regcache_arch (regcache);
> + struct gdbarch *gdbarch = get_regcache_arch (self->regcache);
> enum bfd_endian byte_order_for_code =
> gdbarch_byte_order_for_code (gdbarch);
> unsigned long this_instr =
> @@ -891,14 +892,14 @@ arm_linux_syscall_next_pc (struct regcache *regcache)
> }
> else /* EABI. */
> {
> - svc_number = regcache_raw_get_unsigned (regcache, 7);
> + svc_number = regcache_raw_get_unsigned (self->regcache, 7);
> }
>
> next_pc = pc + 4;
> }
>
> if (svc_number == ARM_SIGRETURN || svc_number == ARM_RT_SIGRETURN)
> - next_pc = arm_linux_sigreturn_next_pc (regcache, svc_number);
> + next_pc = arm_linux_sigreturn_next_pc (self->regcache, svc_number);
>
> /* Addresses for calling Thumb functions have the bit 0 set. */
> if (is_thumb)
> @@ -1485,8 +1486,6 @@ arm_linux_init_abi (struct gdbarch_info info,
> set_gdbarch_stap_parse_special_token (gdbarch,
> arm_stap_parse_special_token);
>
> - tdep->syscall_next_pc = arm_linux_syscall_next_pc;
> -
> /* `catch syscall' */
> set_xml_syscall_file_name (gdbarch, "syscalls/arm-linux.xml");
> set_gdbarch_get_syscall_number (gdbarch, arm_linux_get_syscall_number);
> diff --git a/gdb/arm-tdep.c b/gdb/arm-tdep.c
> index 8874ec8..ccc2a03 100644
> --- a/gdb/arm-tdep.c
> +++ b/gdb/arm-tdep.c
> @@ -237,6 +237,11 @@ static void arm_neon_quad_write (struct gdbarch *gdbarch,
> struct regcache *regcache,
> int regnum, const gdb_byte *buf);
>
> +static CORE_ADDR
> + arm_get_next_pcs_syscall_next_pc (struct arm_get_next_pcs *self,
> + CORE_ADDR pc);
> +
> +

Ditto.

> /* get_next_pcs operations. */
> static struct arm_get_next_pcs_ops arm_get_next_pcs_ops = {
> arm_get_next_pcs_read_memory_unsigned_integer,
> @@ -6142,15 +6147,10 @@ arm_get_next_pcs_addr_bits_remove (struct arm_get_next_pcs *self,
>
> /* Wrapper over syscall_next_pc for use in get_next_pcs. */
>
> -CORE_ADDR
> -arm_get_next_pcs_syscall_next_pc (struct arm_get_next_pcs *self, CORE_ADDR pc)
> +static CORE_ADDR
> +arm_get_next_pcs_syscall_next_pc (struct arm_get_next_pcs *self,
> + CORE_ADDR pc)
> {
> - struct gdbarch_tdep *tdep;
> -
> - tdep = gdbarch_tdep (get_regcache_arch (self->regcache));
> - if (tdep->syscall_next_pc != NULL)
> - return tdep->syscall_next_pc (self->regcache);
> -
> return 0;
> }
>
> diff --git a/gdb/arm-tdep.h b/gdb/arm-tdep.h
> index faa543e..1306cbb 100644
> --- a/gdb/arm-tdep.h
> +++ b/gdb/arm-tdep.h
> @@ -138,10 +138,6 @@ struct gdbarch_tdep
> struct type *neon_double_type;
> struct type *neon_quad_type;
>
> - /* Return the expected next PC if the program is stopped at a syscall
> - instruction. */
> - CORE_ADDR (*syscall_next_pc) (struct regcache *regcache);
> -
> /* syscall record. */
> int (*arm_syscall_record) (struct regcache *regcache, unsigned long svc_number);
> };
> @@ -261,9 +257,6 @@ ULONGEST arm_get_next_pcs_read_memory_unsigned_integer (CORE_ADDR memaddr,
> CORE_ADDR arm_get_next_pcs_addr_bits_remove (struct arm_get_next_pcs *self,
> CORE_ADDR val);
>
> -CORE_ADDR arm_get_next_pcs_syscall_next_pc (struct arm_get_next_pcs *self,
> - CORE_ADDR pc);
> -
> int arm_get_next_pcs_is_thumb (struct arm_get_next_pcs *self);
>
> void arm_insert_single_step_breakpoint (struct gdbarch *,
>

Otherwise LGTM, thanks for the patch.

Antoine