Use VEC for target_desc.reg_defs

Nowadays, target_desc.reg_defs is a pointer points to a pre-generated
array, which is not flexible.  This patch changes it from an array
to a VEC so that GDBserver can create target descriptions dynamically
later.  Instead of using pre-generated array, the -generated.c calls
VEC_safe_push to add each register to vector.

Since target_desc.reg_defs is used in IPA, we need to build common/vec.c
for IPA too.

gdb/gdbserver:

2017-09-05  Yao Qi  <yao.qi@linaro.org>

	* Makefile.in (IPA_OBJS): Add vec-ipa.o
	* regcache.c (get_thread_regcache): Use VEC_length.
	(init_register_cache): Likewise.
	(regcache_cpy): Likewise.
	(registers_to_string): Iterate reg_defs via VEC_iterate.
	(find_regno): Likewise.
	(find_register_by_number): Use VEC_index.
	(register_size): Call find_register_by_number.
	(register_data): Call find_register_by_number.
	(supply_regblock): Use VEC_length.
	(regcache_raw_read_unsigned): Likewise.
	* tdesc.c (init_target_desc): Iterate reg_defs via
	VEC_iterate.
	(default_description): Update initializer.
	(copy_target_description): Don't update field num_registers.
	* tdesc.h (struct target_desc) <reg_defs>: Change it to VEC.
	<num_registers>: Remove.

gdb:

2017-09-05  Yao Qi  <yao.qi@linaro.org>

	* regformats/regdat.sh: Update generated code.

1 files changed, 5 insertions, 6 deletions

diff --git a/gdb/gdbserver/tdesc.h b/gdb/gdbserver/tdesc.h
index 0341278..424a2fd 100644
--- a/gdb/gdbserver/tdesc.h
+++ b/gdb/gdbserver/tdesc.h
@@ -21,17 +21,16 @@
 
 struct reg;
 
+typedef struct reg *tdesc_reg_p;
+DEF_VEC_P(tdesc_reg_p);
+
 /* A target description.  */
 
 struct target_desc
 {
-  /* An array of NUM_REGISTERS elements of register definitions that
+  /* A vector of elements of register definitions that
      describe the inferior's register set.  */
-  struct reg *reg_defs;
-
-  /* The number of registers in inferior's register set (and thus in
-     the regcache).  */
-  int num_registers;
+  VEC(tdesc_reg_p) *reg_defs;
 
   /* The register cache size, in bytes.  */
   int registers_size;