Change management of tdesc_arch_data

While working on something else, I noticed that tdesc_data_cleanup
took a void* parameter.  Looking more into this, I found that
tdesc_use_registers expected a transfer of ownership.

I think it's better to express this sort of thing via the type system,
when possible.  This patch changes tdesc_data_alloc to return a unique
pointer, changes tdesc_use_registers to accept an rvalue reference,
and then adapts all the users.

Note that a deleter structure is introduced to avoid having to move
tdesc_arch_data to the header file.

2020-09-17  Tom Tromey  <tromey@adacore.com>

	* tic6x-tdep.c (tic6x_gdbarch_init): Update.
	* target-descriptions.h (struct tdesc_arch_data_deleter): New.
	(tdesc_arch_data_up): New typedef.
	(tdesc_use_registers, tdesc_data_alloc): Update.
	(tdesc_data_cleanup): Don't declare.
	* target-descriptions.c (tdesc_data_alloc): Return a
	tdesc_arch_data_up.
	(tdesc_arch_data_deleter::operator()): Rename from
	tdesc_data_cleanup.  Change argument type.
	(tdesc_use_registers): Change early_data to an rvalue reference.
	(tdesc_use_registers): Don't use delete.
	* sparc-tdep.c (sparc32_gdbarch_init): Update.
	* s390-tdep.c (s390_gdbarch_init): Update.
	* rx-tdep.c (rx_gdbarch_init): Update.
	* rs6000-tdep.c (rs6000_gdbarch_init): Update.
	* riscv-tdep.c (riscv_gdbarch_init): Update.
	* or1k-tdep.c (or1k_gdbarch_init): Update.
	* nios2-tdep.c (nios2_gdbarch_init): Update.
	* nds32-tdep.c (nds32_gdbarch_init): Update.
	* mips-tdep.c (mips_gdbarch_init): Update.
	* microblaze-tdep.c (microblaze_gdbarch_init): Update.
	* m68k-tdep.c (m68k_gdbarch_init): Update.
	* i386-tdep.c (i386_gdbarch_init): Update.
	* arm-tdep.c (arm_gdbarch_init): Update.
	* arc-tdep.c (arc_tdesc_init): Update.
	(arc_gdbarch_init): Update.
	* aarch64-tdep.c (aarch64_gdbarch_init): Update.

1 files changed, 4 insertions, 6 deletions

diff --git a/gdb/i386-tdep.c b/gdb/i386-tdep.c
index 14e5b31..95cfe5b 100644
--- a/gdb/i386-tdep.c
+++ b/gdb/i386-tdep.c
@@ -8430,7 +8430,6 @@ i386_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
 {
   struct gdbarch_tdep *tdep;
   struct gdbarch *gdbarch;
-  struct tdesc_arch_data *tdesc_data;
   const struct target_desc *tdesc;
   int mm0_regnum;
   int ymm0_regnum;
@@ -8669,7 +8668,7 @@ i386_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
   /* No segment base registers.  */
   tdep->fsbase_regnum = -1;
 
-  tdesc_data = tdesc_data_alloc ();
+  tdesc_arch_data_up tdesc_data = tdesc_data_alloc ();
 
   set_gdbarch_relocate_instruction (gdbarch, i386_relocate_instruction);
 
@@ -8682,12 +8681,11 @@ i386_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
   /* Hook in ABI-specific overrides, if they have been registered.
      Note: If INFO specifies a 64 bit arch, this is where we turn
      a 32-bit i386 into a 64-bit amd64.  */
-  info.tdesc_data = tdesc_data;
+  info.tdesc_data = tdesc_data.get ();
   gdbarch_init_osabi (info, gdbarch);
 
-  if (!i386_validate_tdesc_p (tdep, tdesc_data))
+  if (!i386_validate_tdesc_p (tdep, tdesc_data.get ()))
     {
-      tdesc_data_cleanup (tdesc_data);
       xfree (tdep);
       gdbarch_free (gdbarch);
       return NULL;
@@ -8709,7 +8707,7 @@ i386_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
   /* Target description may be changed.  */
   tdesc = tdep->tdesc;
 
-  tdesc_use_registers (gdbarch, tdesc, tdesc_data);
+  tdesc_use_registers (gdbarch, tdesc, std::move (tdesc_data));
 
   /* Override gdbarch_register_reggroup_p set in tdesc_use_registers.  */
   set_gdbarch_register_reggroup_p (gdbarch, tdep->register_reggroup_p);