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, 22 insertions, 15 deletions

diff --git a/gdb/riscv-tdep.c b/gdb/riscv-tdep.c
index bfd93c65d2..a6a64d3cb8 100644
--- a/gdb/riscv-tdep.c
+++ b/gdb/riscv-tdep.c
@@ -730,7 +730,8 @@ show_riscv_debug_variable (struct ui_file *file, int from_tty,
 int
 riscv_isa_xlen (struct gdbarch *gdbarch)
 {
-  return gdbarch_tdep (gdbarch)->isa_features.xlen;
+  riscv_gdbarch_tdep *tdep = (riscv_gdbarch_tdep *) gdbarch_tdep (gdbarch);
+  return tdep->isa_features.xlen;
 }
 
 /* See riscv-tdep.h.  */
@@ -738,7 +739,8 @@ riscv_isa_xlen (struct gdbarch *gdbarch)
 int
 riscv_abi_xlen (struct gdbarch *gdbarch)
 {
-  return gdbarch_tdep (gdbarch)->abi_features.xlen;
+  riscv_gdbarch_tdep *tdep = (riscv_gdbarch_tdep *) gdbarch_tdep (gdbarch);
+  return tdep->abi_features.xlen;
 }
 
 /* See riscv-tdep.h.  */
@@ -746,7 +748,8 @@ riscv_abi_xlen (struct gdbarch *gdbarch)
 int
 riscv_isa_flen (struct gdbarch *gdbarch)
 {
-  return gdbarch_tdep (gdbarch)->isa_features.flen;
+  riscv_gdbarch_tdep *tdep = (riscv_gdbarch_tdep *) gdbarch_tdep (gdbarch);
+  return tdep->isa_features.flen;
 }
 
 /* See riscv-tdep.h.  */
@@ -754,7 +757,8 @@ riscv_isa_flen (struct gdbarch *gdbarch)
 int
 riscv_abi_flen (struct gdbarch *gdbarch)
 {
-  return gdbarch_tdep (gdbarch)->abi_features.flen;
+  riscv_gdbarch_tdep *tdep = (riscv_gdbarch_tdep *) gdbarch_tdep (gdbarch);
+  return tdep->abi_features.flen;
 }
 
 /* See riscv-tdep.h.  */
@@ -762,7 +766,8 @@ riscv_abi_flen (struct gdbarch *gdbarch)
 bool
 riscv_abi_embedded (struct gdbarch *gdbarch)
 {
-  return gdbarch_tdep (gdbarch)->abi_features.embedded;
+  riscv_gdbarch_tdep *tdep = (riscv_gdbarch_tdep *) gdbarch_tdep (gdbarch);
+  return tdep->abi_features.embedded;
 }
 
 /* Return true if the target for GDBARCH has floating point hardware.  */
@@ -778,7 +783,8 @@ riscv_has_fp_regs (struct gdbarch *gdbarch)
 static bool
 riscv_has_fp_abi (struct gdbarch *gdbarch)
 {
-  return gdbarch_tdep (gdbarch)->abi_features.flen > 0;
+  riscv_gdbarch_tdep *tdep = (riscv_gdbarch_tdep *) gdbarch_tdep (gdbarch);
+  return tdep->abi_features.flen > 0;
 }
 
 /* Return true if REGNO is a floating pointer register.  */
@@ -901,7 +907,7 @@ riscv_register_name (struct gdbarch *gdbarch, int regnum)
      will show up in 'info register all'.  Unless, we identify the
      duplicate copies of these registers (in riscv_tdesc_unknown_reg) and
      then hide the registers here by giving them no name.  */
-  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+  riscv_gdbarch_tdep *tdep = (riscv_gdbarch_tdep *) gdbarch_tdep (gdbarch);
   if (tdep->duplicate_fflags_regnum == regnum)
     return NULL;
   if (tdep->duplicate_frm_regnum == regnum)
@@ -929,7 +935,7 @@ riscv_register_name (struct gdbarch *gdbarch, int regnum)
 static struct type *
 riscv_fpreg_d_type (struct gdbarch *gdbarch)
 {
-  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+  riscv_gdbarch_tdep *tdep = (riscv_gdbarch_tdep *) gdbarch_tdep (gdbarch);
 
   if (tdep->riscv_fpreg_d_type == nullptr)
     {
@@ -1251,7 +1257,7 @@ riscv_is_regnum_a_named_csr (int regnum)
 static bool
 riscv_is_unknown_csr (struct gdbarch *gdbarch, int regnum)
 {
-  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+  riscv_gdbarch_tdep *tdep = (riscv_gdbarch_tdep *) gdbarch_tdep (gdbarch);
   return (regnum >= tdep->unknown_csrs_first_regnum
 	  && regnum < (tdep->unknown_csrs_first_regnum
 		       + tdep->unknown_csrs_count));
@@ -3560,7 +3566,7 @@ riscv_tdesc_unknown_reg (struct gdbarch *gdbarch, tdesc_feature *feature,
      record their register numbers here.  */
   if (strcmp (tdesc_feature_name (feature), riscv_freg_feature.name ()) == 0)
     {
-      struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+      riscv_gdbarch_tdep *tdep = (riscv_gdbarch_tdep *) gdbarch_tdep (gdbarch);
       int *regnum_ptr = nullptr;
 
       if (strcmp (reg_name, "fflags") == 0)
@@ -3591,7 +3597,7 @@ riscv_tdesc_unknown_reg (struct gdbarch *gdbarch, tdesc_feature *feature,
      about register groups in riscv_register_reggroup_p.  */
   if (strcmp (tdesc_feature_name (feature), riscv_csr_feature.name ()) == 0)
     {
-      struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+      riscv_gdbarch_tdep *tdep = (riscv_gdbarch_tdep *) gdbarch_tdep (gdbarch);
       if (tdep->unknown_csrs_first_regnum == -1)
 	tdep->unknown_csrs_first_regnum = possible_regnum;
       gdb_assert (tdep->unknown_csrs_first_regnum
@@ -3628,7 +3634,6 @@ riscv_gdbarch_init (struct gdbarch_info info,
 		    struct gdbarch_list *arches)
 {
   struct gdbarch *gdbarch;
-  struct gdbarch_tdep *tdep;
   struct riscv_gdbarch_features features;
   const struct target_desc *tdesc = info.target_desc;
 
@@ -3693,7 +3698,8 @@ riscv_gdbarch_init (struct gdbarch_info info,
       /* Check that the feature set of the ARCHES matches the feature set
 	 we are looking for.  If it doesn't then we can't reuse this
 	 gdbarch.  */
-      struct gdbarch_tdep *other_tdep = gdbarch_tdep (arches->gdbarch);
+      riscv_gdbarch_tdep *other_tdep
+	= (riscv_gdbarch_tdep *) gdbarch_tdep (arches->gdbarch);
 
       if (other_tdep->isa_features != features
 	  || other_tdep->abi_features != abi_features)
@@ -3706,7 +3712,7 @@ riscv_gdbarch_init (struct gdbarch_info info,
     return arches->gdbarch;
 
   /* None found, so create a new architecture from the information provided.  */
-  tdep = new (struct gdbarch_tdep);
+  riscv_gdbarch_tdep *tdep = new riscv_gdbarch_tdep;
   gdbarch = gdbarch_alloc (&info, tdep);
   tdep->isa_features = features;
   tdep->abi_features = abi_features;
@@ -3812,7 +3818,8 @@ static CORE_ADDR
 riscv_next_pc (struct regcache *regcache, CORE_ADDR pc)
 {
   struct gdbarch *gdbarch = regcache->arch ();
-  const struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+  const riscv_gdbarch_tdep *tdep
+    = (riscv_gdbarch_tdep *) gdbarch_tdep (gdbarch);
   struct riscv_insn insn;
   CORE_ADDR next_pc;