Re: [PATCH] Remove PC from syscall_next_pc

[Antoine Tremblay <antoine.tremblay@ericsson.com>]

Yao Qi writes:

> Method syscall_next_pc of struct arm_get_next_pcs_ops has an argument
> PC, which is not necessary, because PC can be got from regcache in
> 'struct arm_get_next_pcs'.  This patch removes the PC argument of
> syscall_next_pc.
>
> Regression tested on arm-linux.
>
> gdb:
>
> 2016-02-15  Yao Qi  <yao.qi@linaro.org>
>
> 	* arch/arm-get-next-pcs.h (struct arm_get_next_pcs_ops)
> 	<syscall_next_pc>: Remove argument PC.  Callers updated.
> 	* arm-linux-tdep.c (arm_linux_get_next_pcs_syscall_next_pc):
> 	Remove argument PC.  Get pc from regcache_read_pc.
> 	* arm-tdep.c (arm_get_next_pcs_syscall_next_pc): Remove
> 	argument PC.
>
> gdb/gdbserver:
>
> 2016-02-15  Yao Qi  <yao.qi@linaro.org>
>
> 	* linux-arm-low.c (get_next_pcs_syscall_next_pc): Remove argument
> 	PC.  Get pc from regcache_read_pc.
> ---
>  gdb/arch/arm-get-next-pcs.c   | 4 ++--
>  gdb/arch/arm-get-next-pcs.h   | 2 +-
>  gdb/arm-linux-tdep.c          | 7 +++----
>  gdb/arm-tdep.c                | 6 ++----
>  gdb/gdbserver/linux-arm-low.c | 6 +++---
>  5 files changed, 11 insertions(+), 14 deletions(-)
>
> diff --git a/gdb/arch/arm-get-next-pcs.c b/gdb/arch/arm-get-next-pcs.c
> index 8404869..f3e9fd9 100644
> --- a/gdb/arch/arm-get-next-pcs.c
> +++ b/gdb/arch/arm-get-next-pcs.c
> @@ -417,7 +417,7 @@ thumb_get_next_pcs_raw (struct arm_get_next_pcs *self)
>        unsigned long cond = bits (inst1, 8, 11);
>        if (cond == 0x0f)  /* 0x0f = SWI */
>  	{
> -	  nextpc = self->ops->syscall_next_pc (self, pc);
> +	  nextpc = self->ops->syscall_next_pc (self);
>  	}
>        else if (cond != 0x0f && condition_true (cond, status))
>  	nextpc = pc_val + (sbits (inst1, 0, 7) << 1);
> @@ -889,7 +889,7 @@ arm_get_next_pcs_raw (struct arm_get_next_pcs *self)
>  	  break;
>  	case 0xf:		/* SWI */
>  	  {
> -	    nextpc = self->ops->syscall_next_pc (self, pc);
> +	    nextpc = self->ops->syscall_next_pc (self);
>  	  }
>  	  break;
>  
> diff --git a/gdb/arch/arm-get-next-pcs.h b/gdb/arch/arm-get-next-pcs.h
> index e038982..5525ee2 100644
> --- a/gdb/arch/arm-get-next-pcs.h
> +++ b/gdb/arch/arm-get-next-pcs.h
> @@ -28,7 +28,7 @@ struct arm_get_next_pcs;
>  struct arm_get_next_pcs_ops
>  {
>    ULONGEST (*read_mem_uint) (CORE_ADDR memaddr, int len, int byte_order);
> -  CORE_ADDR (*syscall_next_pc) (struct arm_get_next_pcs *self, CORE_ADDR pc);
> +  CORE_ADDR (*syscall_next_pc) (struct arm_get_next_pcs *self);
>    CORE_ADDR (*addr_bits_remove) (struct arm_get_next_pcs *self, CORE_ADDR val);
>    int (*is_thumb) (struct arm_get_next_pcs *self);
>  
> diff --git a/gdb/arm-linux-tdep.c b/gdb/arm-linux-tdep.c
> index e416e28..46d54bc 100644
> --- a/gdb/arm-linux-tdep.c
> +++ b/gdb/arm-linux-tdep.c
> @@ -266,8 +266,7 @@ static const gdb_byte arm_linux_thumb2_le_breakpoint[] = { 0xf0, 0xf7, 0x00, 0xa
>  #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);
> +  arm_linux_get_next_pcs_syscall_next_pc (struct arm_get_next_pcs *self);
>  
>  /* Operation function pointers for get_next_pcs.  */
>  static struct arm_get_next_pcs_ops arm_linux_get_next_pcs_ops = {
> @@ -872,10 +871,10 @@ arm_linux_get_syscall_number (struct gdbarch *gdbarch,
>  }
>  
>  static CORE_ADDR
> -arm_linux_get_next_pcs_syscall_next_pc (struct arm_get_next_pcs *self,
> -					CORE_ADDR pc)
> +arm_linux_get_next_pcs_syscall_next_pc (struct arm_get_next_pcs *self)
>  {
>    CORE_ADDR next_pc = 0;
> +  CORE_ADDR pc = regcache_read_pc (self->regcache);
>    int is_thumb = arm_is_thumb (self->regcache);
>    ULONGEST svc_number = 0;
>    struct gdbarch *gdbarch = get_regcache_arch (self->regcache);
> diff --git a/gdb/arm-tdep.c b/gdb/arm-tdep.c
> index 048406a..9bd48a2 100644
> --- a/gdb/arm-tdep.c
> +++ b/gdb/arm-tdep.c
> @@ -238,8 +238,7 @@ static void arm_neon_quad_write (struct gdbarch *gdbarch,
>  				 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);
> +  arm_get_next_pcs_syscall_next_pc (struct arm_get_next_pcs *self);
>  
>  
>  /* get_next_pcs operations.  */
> @@ -6139,8 +6138,7 @@ arm_get_next_pcs_addr_bits_remove (struct arm_get_next_pcs *self,
>  /* Wrapper over syscall_next_pc for use in get_next_pcs.  */
>  
>  static CORE_ADDR
> -arm_get_next_pcs_syscall_next_pc (struct arm_get_next_pcs *self,
> -				  CORE_ADDR pc)
> +arm_get_next_pcs_syscall_next_pc (struct arm_get_next_pcs *self)
>  {
>    return 0;
>  }
> diff --git a/gdb/gdbserver/linux-arm-low.c b/gdb/gdbserver/linux-arm-low.c
> index 365f1c9..57826f1 100644
> --- a/gdb/gdbserver/linux-arm-low.c
> +++ b/gdb/gdbserver/linux-arm-low.c
> @@ -147,8 +147,7 @@ static ULONGEST get_next_pcs_read_memory_unsigned_integer (CORE_ADDR memaddr,
>  static CORE_ADDR get_next_pcs_addr_bits_remove (struct arm_get_next_pcs *self,
>  						CORE_ADDR val);
>  
> -static CORE_ADDR get_next_pcs_syscall_next_pc (struct arm_get_next_pcs *self,
> -					       CORE_ADDR pc);
> +static CORE_ADDR get_next_pcs_syscall_next_pc (struct arm_get_next_pcs *self);
>  
>  static int get_next_pcs_is_thumb (struct arm_get_next_pcs *self);
>  
> @@ -786,9 +785,10 @@ arm_sigreturn_next_pc (struct regcache *regcache, int svc_number,
>  /* When PC is at a syscall instruction, return the PC of the next
>     instruction to be executed.  */
>  static CORE_ADDR
> -get_next_pcs_syscall_next_pc (struct arm_get_next_pcs *self, CORE_ADDR pc)
> +get_next_pcs_syscall_next_pc (struct arm_get_next_pcs *self)
>  {
>    CORE_ADDR next_pc = 0;
> +  CORE_ADDR pc = regcache_read_pc (self->regcache);
>    int is_thumb = arm_is_thumb_mode ();
>    ULONGEST svc_number = 0;
>    struct regcache *regcache = self->regcache;

LGTM, thanks for this.

Antoine