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, 6 insertions, 11 deletions

diff --git a/gdb/target-descriptions.c b/gdb/target-descriptions.c
index 91cbeb58b04..19dbcbeac39 100644
--- a/gdb/target-descriptions.c
+++ b/gdb/target-descriptions.c
@@ -779,21 +779,17 @@ tdesc_data_init (struct obstack *obstack)
 /* Similar, but for the temporary copy used during architecture
    initialization.  */
 
-struct tdesc_arch_data *
+tdesc_arch_data_up
 tdesc_data_alloc (void)
 {
-  return new tdesc_arch_data ();
+  return tdesc_arch_data_up (new tdesc_arch_data ());
 }
 
-/* Free something allocated by tdesc_data_alloc, if it is not going
-   to be used (for instance if it was unsuitable for the
-   architecture).  */
+/* See target-descriptions.h.  */
 
 void
-tdesc_data_cleanup (void *data_untyped)
+tdesc_arch_data_deleter::operator() (struct tdesc_arch_data *data) const
 {
-  struct tdesc_arch_data *data = (struct tdesc_arch_data *) data_untyped;
-
   delete data;
 }
 
@@ -1103,7 +1099,7 @@ set_tdesc_pseudo_register_reggroup_p
 void
 tdesc_use_registers (struct gdbarch *gdbarch,
 		     const struct target_desc *target_desc,
-		     struct tdesc_arch_data *early_data,
+		     tdesc_arch_data_up &&early_data,
 		     tdesc_unknown_register_ftype unk_reg_cb)
 {
   int num_regs = gdbarch_num_regs (gdbarch);
@@ -1116,8 +1112,7 @@ tdesc_use_registers (struct gdbarch *gdbarch,
   gdb_assert (tdesc_has_registers (target_desc));
 
   data = (struct tdesc_arch_data *) gdbarch_data (gdbarch, tdesc_data);
-  data->arch_regs = early_data->arch_regs;
-  delete early_data;
+  data->arch_regs = std::move (early_data->arch_regs);
 
   /* Build up a set of all registers, so that we can assign register
      numbers where needed.  The hash table expands as necessary, so