RISC-V: Merged extension string tables and their version tables into one.

There are two main reasons for this patch,

* In the past we had two extension tables, one is used to record all
supported extensions in bfd/elfxx-riscv.c, another is used to get the
default extension versions in gas/config/tc-riscv.c.  It is hard to
maintain lots of tables in different files, but in fact we can merge
them into just one table.  Therefore, we now define many riscv_supported_std*
tables, which record names and versions for all supported extensions.
We not only use these tables to initialize the riscv_ext_order, but
also use them to get the default versions of extensions, and decide if
the extensions should be enbaled by default.

* We add a new filed `default_enable' for the riscv_supported_std* tables,
to decide if the extension should be enabled by default.  For now if the
`default_enable' field of the extension is set to EXT_DEFAULT, then we
should enable the extension when the -march and elf architecture attributes
are not set.  In the future, I suppose the `default_enable' can be set
to lots of EXT_<VENDOR>, each vendor can decide to open which extensions,
when the target triple of vendor is chosen.

The elf/linux regression tests of riscv-gnu-toolchain are passed.

bfd/
	* elfnn-riscv.c (cpu-riscv.h): Removed sine it is included in
	bfd/elfxx-riscv.h.
	(riscv_merge_std_ext): Updated since the field of rpe is changed.
	* elfxx-riscv.c (cpu-riscv.h): Removed.
	(riscv_implicit_subsets): Added implicit extensions for g.
	(struct riscv_supported_ext): Used to be riscv_ext_version.  Moved
	from gas/config/tc-riscv.c, and added new field `default_enable' to
	decide if the extension should be enabled by default.
	(EXT_DEFAULT): Defined for `default_enable' field.
	(riscv_supported_std_ext): It used to return the supported standard
	architecture string, but now we move ext_version_table from
	gas/config/tc-riscv.c to here, and rename it to riscv_supported_std_ext.
	Currently we not only use the table to initialize riscv_ext_order, but
	also get the default versions of extensions, and decide if the extensions
	should be enbaled by default.
	(riscv_supported_std_z_ext): Likewise, but is used for z* extensions.
	(riscv_supported_std_s_ext): Likewise, but is used for s* extensions.
	(riscv_supported_std_h_ext): Likewise, but is used for h* extensions.
	(riscv_supported_std_zxm_ext): Likewise, but is used for zxm* extensions.
	(riscv_all_supported_ext): Includes all supported extension tables.
	(riscv_known_prefixed_ext): Updated.
	(riscv_valid_prefixed_ext): Updated.
	(riscv_init_ext_order): Init the riscv_ext_order table according to
	riscv_supported_std_ext.
	(riscv_get_default_ext_version): Moved from gas/config/tc-riscv.c.
	Get the versions of extensions from riscv_supported_std* tables.
	(riscv_parse_add_subset): Updated.
	(riscv_parse_std_ext): Updated.
	(riscv_set_default_arch): Set the default subset list according to
	the default_enable field of riscv_supported_*ext tables.
	(riscv_parse_subset): If the input ARCH is NULL, then we call
	riscv_set_default_arch to set the default subset list.
	* elfxx-riscv.h (cpu-riscv.h): Included.
	(riscv_parse_subset_t): Removed get_default_version field, and added
	isa_spec field to replace it.
	(extern riscv_supported_std_ext): Removed.
gas/
	* (bfd/cpu-riscv.h): Removed.
	(struct riscv_ext_version): Renamed and moved to bfd/elfxx-riscv.c.
	(ext_version_table): Likewise.
	(riscv_get_default_ext_version): Likewise.
	(ext_version_hash): Removed.
	(init_ext_version_hash): Removed.
	(riscv_set_arch): Updated since the field of rps is changed.  Besides,
	report error when the architecture string is empty.
	(riscv_after_parse_args): Updated.

1 files changed, 3 insertions, 4 deletions

diff --git a/bfd/elfnn-riscv.c b/bfd/elfnn-riscv.c
index a10384c..2e8df72 100644
--- a/bfd/elfnn-riscv.c
+++ b/bfd/elfnn-riscv.c
@@ -32,7 +32,6 @@
 #include "elf/riscv.h"
 #include "opcode/riscv.h"
 #include "objalloc.h"
-#include "cpu-riscv.h"
 
 #include <limits.h>
 #ifndef CHAR_BIT
@@ -3443,7 +3442,7 @@ riscv_merge_std_ext (bfd *ibfd,
 		     struct riscv_subset_t **pin,
 		     struct riscv_subset_t **pout)
 {
-  const char *standard_exts = riscv_supported_std_ext ();
+  const char *standard_exts = "mafdqlcbjtpvn";
   const char *p;
   struct riscv_subset_t *in = *pin;
   struct riscv_subset_t *out = *pout;
@@ -3587,13 +3586,13 @@ riscv_merge_arch_attr_info (bfd *ibfd, char *in_arch, char *out_arch)
   rpe_in.subset_list = &in_subsets;
   rpe_in.error_handler = _bfd_error_handler;
   rpe_in.xlen = &xlen_in;
-  rpe_in.get_default_version = NULL;
+  rpe_in.isa_spec = ISA_SPEC_CLASS_NONE;
   rpe_in.check_unknown_prefixed_ext = false;
 
   rpe_out.subset_list = &out_subsets;
   rpe_out.error_handler = _bfd_error_handler;
   rpe_out.xlen = &xlen_out;
-  rpe_out.get_default_version = NULL;
+  rpe_out.isa_spec = ISA_SPEC_CLASS_NONE;
   rpe_out.check_unknown_prefixed_ext = false;
 
   if (in_arch == NULL && out_arch == NULL)