gdb: fix gdbarch_tdep ODR violation

I would like to be able to use non-trivial types in gdbarch_tdep types.
This is not possible at the moment (in theory), because of the one
definition rule.

To allow it, rename all gdbarch_tdep types to <arch>_gdbarch_tdep, and
make them inherit from a gdbarch_tdep base class.  The inheritance is
necessary to be able to pass pointers to all these <arch>_gdbarch_tdep
objects to gdbarch_alloc, which takes a pointer to gdbarch_tdep.

These objects are never deleted through a base class pointer, so I
didn't include a virtual destructor.  In the future, if gdbarch objects
deletable, I could imagine that the gdbarch_tdep objects could become
owned by the gdbarch objects, and then it would become useful to have a
virtual destructor (so that the gdbarch object can delete the owned
gdbarch_tdep object).  But that's not necessary right now.

It turns out that RISC-V already has a gdbarch_tdep that is
non-default-constructible, so that provides a good motivation for this
change.

Most changes are fairly straightforward, mostly needing to add some
casts all over the place.  There is however the xtensa architecture,
doing its own little weird thing to define its gdbarch_tdep.  I did my
best to adapt it, but I can't test those changes.

Change-Id: Ic001903f91ddd106bd6ca09a79dabe8df2d69f3b

1 files changed, 10 insertions, 9 deletions

diff --git a/gdb/rs6000-aix-tdep.c b/gdb/rs6000-aix-tdep.c
index 80e1957..11cae6a 100644
--- a/gdb/rs6000-aix-tdep.c
+++ b/gdb/rs6000-aix-tdep.c
@@ -73,7 +73,7 @@ aix_sighandle_frame_cache (struct frame_info *this_frame,
   LONGEST backchain;
   CORE_ADDR base, base_orig, func;
   struct gdbarch *gdbarch = get_frame_arch (this_frame);
-  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+  ppc_gdbarch_tdep *tdep = (ppc_gdbarch_tdep *) gdbarch_tdep (gdbarch);
   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
   struct trad_frame_cache *this_trad_cache;
 
@@ -259,7 +259,8 @@ rs6000_aix_iterate_over_regset_sections (struct gdbarch *gdbarch,
 					 void *cb_data,
 					 const struct regcache *regcache)
 {
-  if (gdbarch_tdep (gdbarch)->wordsize == 4)
+  ppc_gdbarch_tdep *tdep = (ppc_gdbarch_tdep *) gdbarch_tdep (gdbarch);
+  if (tdep->wordsize == 4)
     cb (".reg", 592, 592, &rs6000_aix32_regset, NULL, cb_data);
   else
     cb (".reg", 576, 576, &rs6000_aix64_regset, NULL, cb_data);
@@ -289,7 +290,7 @@ rs6000_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
 			function_call_return_method return_method,
 			CORE_ADDR struct_addr)
 {
-  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+  ppc_gdbarch_tdep *tdep = (ppc_gdbarch_tdep *) gdbarch_tdep (gdbarch);
   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
   int ii;
   int len = 0;
@@ -297,7 +298,7 @@ rs6000_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
   int argbytes;			/* current argument byte */
   gdb_byte tmp_buffer[50];
   int f_argno = 0;		/* current floating point argno */
-  int wordsize = gdbarch_tdep (gdbarch)->wordsize;
+  int wordsize = tdep->wordsize;
   CORE_ADDR func_addr = find_function_addr (function, NULL);
 
   struct value *arg = 0;
@@ -519,7 +520,7 @@ rs6000_return_value (struct gdbarch *gdbarch, struct value *function,
 		     struct type *valtype, struct regcache *regcache,
 		     gdb_byte *readbuf, const gdb_byte *writebuf)
 {
-  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+  ppc_gdbarch_tdep *tdep = (ppc_gdbarch_tdep *) gdbarch_tdep (gdbarch);
   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
 
   /* The calling convention this function implements assumes the
@@ -657,7 +658,7 @@ rs6000_convert_from_func_ptr_addr (struct gdbarch *gdbarch,
 				   CORE_ADDR addr,
 				   struct target_ops *targ)
 {
-  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+  ppc_gdbarch_tdep *tdep = (ppc_gdbarch_tdep *) gdbarch_tdep (gdbarch);
   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
   struct obj_section *s;
 
@@ -701,7 +702,7 @@ branch_dest (struct regcache *regcache, int opcode, int instr,
 	     CORE_ADDR pc, CORE_ADDR safety)
 {
   struct gdbarch *gdbarch = regcache->arch ();
-  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+  ppc_gdbarch_tdep *tdep = (ppc_gdbarch_tdep *) gdbarch_tdep (gdbarch);
   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
   CORE_ADDR dest;
   int immediate;
@@ -969,7 +970,7 @@ static struct ld_info
 rs6000_aix_extract_ld_info (struct gdbarch *gdbarch,
 			    const gdb_byte *ldi_buf)
 {
-  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+  ppc_gdbarch_tdep *tdep = (ppc_gdbarch_tdep *) gdbarch_tdep (gdbarch);
   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
   struct type *ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
   const struct ld_info_desc desc
@@ -1128,7 +1129,7 @@ rs6000_aix_core_xfer_shared_libraries_aix (struct gdbarch *gdbarch,
 static void
 rs6000_aix_init_osabi (struct gdbarch_info info, struct gdbarch *gdbarch)
 {
-  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+  ppc_gdbarch_tdep *tdep = (ppc_gdbarch_tdep *) gdbarch_tdep (gdbarch);
 
   /* RS6000/AIX does not support PT_STEP.  Has to be simulated.  */
   set_gdbarch_software_single_step (gdbarch, rs6000_software_single_step);