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, 2 insertions, 6 deletions

diff --git a/bfd/elfxx-riscv.h b/bfd/elfxx-riscv.h
index 6a2501b..e691a97 100644
--- a/bfd/elfxx-riscv.h
+++ b/bfd/elfxx-riscv.h
@@ -23,6 +23,7 @@
 #include "elf/common.h"
 #include "elf/internal.h"
 #include "opcode/riscv.h"
+#include "cpu-riscv.h"
 
 #define RISCV_UNKNOWN_VERSION -1
 
@@ -71,9 +72,7 @@ typedef struct
   void (*error_handler) (const char *,
 			 ...) ATTRIBUTE_PRINTF_1;
   unsigned *xlen;
-  void (*get_default_version) (const char *,
-			       int *,
-			       int *);
+  enum riscv_spec_class isa_spec;
   bool check_unknown_prefixed_ext;
 } riscv_parse_subset_t;
 
@@ -81,9 +80,6 @@ extern bool
 riscv_parse_subset (riscv_parse_subset_t *,
 		    const char *);
 
-extern const char *
-riscv_supported_std_ext (void);
-
 extern void
 riscv_release_subset_list (riscv_subset_list_t *);