Re: [PATCH 7/11] Add BFIN_MAX_REGISTER_SIZE

[Alan Hayward <Alan.Hayward@arm.com>]

> On 5 Apr 2017, at 15:10, Yao Qi <qiyaoltc@gmail.com> wrote:
> 
> Alan Hayward <Alan.Hayward@arm.com> writes:
> 
>> Is it not clearer code to add and use a macro rather than a magic number ?
>> 
> 
> Macro is better, but "buf[4]" is not that magic, because it is only used
> within bfin_pseudo_register_read, or we can define ASTAT_REGISTER_SIZE.
> 
>> It’s also not obvious anywhere that the astat register is 32bits. I had to go
>> digging inside regformats/reg-bfin.dat before I found it out.
> 
> It is easier to figure out the size of a specific register than the max
> size of a set of registers.
> 
>> 
>> Given that BFIN_MAX_REGISTER_SIZE is also 4, it compiles to the same
>> size anyway.
> 
> "gdb_byte buf[BFIN_MAX_REGISTER_SIZE]" is fine to me.  Could you define
> BFIN_MAX_REGISTER_SIZE in bfin-tdep.c instead of .h?  It is not used
> elsewhere.
> 

Ok, pushed the following:

2017-04-07  Alan Hayward  <alan.hayward@arm.com>

	* bfin-tdep.c (BFIN_MAX_REGISTER_SIZE): Add.
	(bfin_pseudo_register_read): Use BFIN_MAX_REGISTER_SIZE.
	(bfin_pseudo_register_write): Likewise


diff --git a/gdb/bfin-tdep.c b/gdb/bfin-tdep.c
index 3df1ba387a323dc6827b1189432f8877d1833184..c590a9132c00f539b5c6e57b8f156845ff50acad 100644
--- a/gdb/bfin-tdep.c
+++ b/gdb/bfin-tdep.c
@@ -241,6 +241,8 @@ static const int map_gcc_gdb[] =
   BFIN_LB1_REGNUM
 };

+/* Big enough to hold the size of the largest register in bytes.  */
+#define BFIN_MAX_REGISTER_SIZE	4

 struct bfin_frame_cache
 {
@@ -689,7 +691,7 @@ static enum register_status
 bfin_pseudo_register_read (struct gdbarch *gdbarch, struct regcache *regcache,
 			   int regnum, gdb_byte *buffer)
 {
-  gdb_byte *buf = (gdb_byte *) alloca (MAX_REGISTER_SIZE);
+  gdb_byte buf[BFIN_MAX_REGISTER_SIZE];
   enum register_status status;

   if (regnum != BFIN_CC_REGNUM)
@@ -710,7 +712,7 @@ static void
 bfin_pseudo_register_write (struct gdbarch *gdbarch, struct regcache *regcache,
 			    int regnum, const gdb_byte *buffer)
 {
-  gdb_byte *buf = (gdb_byte *) alloca (MAX_REGISTER_SIZE);
+  gdb_byte buf[BFIN_MAX_REGISTER_SIZE];

   if (regnum != BFIN_CC_REGNUM)
     internal_error (__FILE__, __LINE__,