RISC-V: Support ELF attribute for gas and readelf.

	2019-01-16  Kito Cheng  <kito@andestech.com>
		    Nelson Chu  <nelson@andestech.com>

	bfd/
	* elfnn-riscv.c (riscv_elf_obj_attrs_arg_type): New.
	(elf_backend_obj_attrs_vendor): Define.
	(elf_backend_obj_attrs_section_type): Likewise.
	(elf_backend_obj_attrs_section): Likewise.
	(elf_backend_obj_attrs_arg_type): Define as
	riscv_elf_obj_attrs_arg_type.
	* elfxx-riscv.c (riscv_estimate_digit): New.
	(riscv_estimate_arch_strlen1): Likewise.
	(riscv_estimate_arch_strlen): Likewise.
	(riscv_arch_str1): Likewise.
	(riscv_arch_str): Likewise.
	* elfxx-riscv.h (riscv_arch_str): Declare.
	binutils/
	* readelf.c (get_riscv_section_type_name): New function.
	(get_section_type_name): Add handler for RISC-V.
	(riscv_attr_tag_t): Declare.
	(riscv_attr_tag): New.
	(display_riscv_attribute): New function.
	(process_attributes): Add handler for RISC-V.
	* testsuite/binutils-all/strip-3.d: Remove .riscv.attribute
	section.
	gas/
	* config/tc-riscv.c (DEFAULT_RISCV_ATTR): Define to 0 if not defined.
	(riscv_set_options): Add `arch_attr` field.
	(riscv_opts): Set default value for arch_attr.
	(riscv_write_out_arch_attr): New.
	(riscv_set_public_attributes): Likewise.
	(riscv_md_end): Likewise.
	(riscv_convert_symbolic_attribute): Likewise.
	(s_riscv_attribute): Likewise.
	(explicit_arch_attr): Likewise.
	(riscv_pseudo_table): Add .attribute to the table.
	(options): Add OPTION_ARCH_ATTR and OPTION_NO_ARCH_ATTR
	enumeration constants.
	(md_longopts): Add `march-attr' and `mno-arch-attr' options.
	(md_parse_option): Handle the new options.
	(md_show_usage): Document the `march-attr' option.
	* config/tc-riscv.h (md_end): Define as riscv_md_end
	(riscv_md_end): Declare.
	(CONVERT_SYMBOLIC_ATTRIBUTE): Define as
	riscv_convert_symbolic_attribute.
	(riscv_convert_symbolic_attribute): Declare.
	(start_assemble): Declare.
	* testsuite/gas/elf/elf.exp: Adjust test case for section2.e.
	* testsuite/gas/elf/section2.e-riscv: New.
	* testsuite/gas/riscv/attribute-01.d: New test
	* testsuite/gas/riscv/attribute-02.d: Likewise.
	* testsuite/gas/riscv/attribute-03.d: Likewise.
	* testsuite/gas/riscv/attribute-04.d: Likewise.
	* testsuite/gas/riscv/attribute-04.s: Likewise.
	* testsuite/gas/riscv/attribute-05.d: Likewise.
	* testsuite/gas/riscv/attribute-05.s: Likewise.
	* testsuite/gas/riscv/attribute-06.d: Likewise.
	* testsuite/gas/riscv/attribute-06.s: Likewise.
	* testsuite/gas/riscv/attribute-07.d: Likewise.
	* testsuite/gas/riscv/attribute-07.s: Likewise.
	* testsuite/gas/riscv/attribute-08.d: Likewise.
	* testsuite/gas/riscv/attribute-08.s: Likewise.
	* testsuite/gas/riscv/attribute-unknown.d: Likewise.
	* testsuite/gas/riscv/attribute-unknown.s: Likewise.
	* testsuite/gas/riscv/empty.l: Likewise.
	* doc/c-riscv.texi (.attribute): Add documentation.
	* configure.ac (--enable-default-riscv-attribute): New options.
	* configure: Re-generate.
	* config.in: Re-generate.
	include/
	* elf/riscv.h (SHT_RISCV_ATTRIBUTES): Define.
	(Tag_RISCV_arch): Likewise.
	(Tag_RISCV_priv_spec): Likewise.
	(Tag_RISCV_priv_spec_minor): Likewise.
	(Tag_RISCV_priv_spec_revision): Likewise.
	(Tag_RISCV_unaligned_access): Likewise.
	(Tag_RISCV_stack_align): Likewise.

4 files changed, 125 insertions, 0 deletions

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 5e943a1..cea6d70 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,19 @@
+2019-01-16  Kito Cheng  <kito@andestech.com>
+	    Nelson Chu  <nelson@andestech.com>
+
+	* elfnn-riscv.c (riscv_elf_obj_attrs_arg_type): New.
+	(elf_backend_obj_attrs_vendor): Define.
+	(elf_backend_obj_attrs_section_type): Likewise.
+	(elf_backend_obj_attrs_section): Likewise.
+	(elf_backend_obj_attrs_arg_type): Define as
+	riscv_elf_obj_attrs_arg_type.
+	* elfxx-riscv.c (riscv_estimate_digit): New.
+	(riscv_estimate_arch_strlen1): Likewise.
+	(riscv_estimate_arch_strlen): Likewise.
+	(riscv_arch_str1): Likewise.
+	(riscv_arch_str): Likewise.
+	* elfxx-riscv.h (riscv_arch_str): Declare.
+
 2019-01-14  John Darrington <john@darrington.wattle.id.au>
 
 	* bfd-in2.h [BFD_RELOC_S12Z_OPR]: New reloc.
diff --git a/bfd/elfnn-riscv.c b/bfd/elfnn-riscv.c
index 78ab051..5430f61 100644
--- a/bfd/elfnn-riscv.c
+++ b/bfd/elfnn-riscv.c
@@ -3654,6 +3654,14 @@ riscv_elf_object_p (bfd *abfd)
   return TRUE;
 }
 
+/* Determine whether an object attribute tag takes an integer, a
+   string or both.  */
+
+static int
+riscv_elf_obj_attrs_arg_type (int tag)
+{
+  return (tag & 1) != 0 ? ATTR_TYPE_FLAG_STR_VAL : ATTR_TYPE_FLAG_INT_VAL;
+}
 
 #define TARGET_LITTLE_SYM		riscv_elfNN_vec
 #define TARGET_LITTLE_NAME		"elfNN-littleriscv"
@@ -3696,4 +3704,13 @@ riscv_elf_object_p (bfd *abfd)
 #define elf_backend_rela_normal		1
 #define elf_backend_default_execstack	0
 
+#undef  elf_backend_obj_attrs_vendor
+#define elf_backend_obj_attrs_vendor            "riscv"
+#undef  elf_backend_obj_attrs_arg_type
+#define elf_backend_obj_attrs_arg_type          riscv_elf_obj_attrs_arg_type
+#undef  elf_backend_obj_attrs_section_type
+#define elf_backend_obj_attrs_section_type      SHT_RISCV_ATTRIBUTES
+#undef  elf_backend_obj_attrs_section
+#define elf_backend_obj_attrs_section           ".riscv.attributes"
+
 #include "elfNN-target.h"
diff --git a/bfd/elfxx-riscv.c b/bfd/elfxx-riscv.c
index 535ba7b..29592db 100644
--- a/bfd/elfxx-riscv.c
+++ b/bfd/elfxx-riscv.c
@@ -1484,3 +1484,92 @@ riscv_release_subset_list (riscv_subset_list_t *subset_list)
 
   subset_list->tail = NULL;
 }
+
+/* Return the number of digits for the input.  */
+
+static size_t
+riscv_estimate_digit (unsigned num)
+{
+  size_t digit = 0;
+  if (num == 0)
+    return 1;
+
+  for (digit = 0; num ; num /= 10)
+    digit++;
+
+  return digit;
+}
+
+/* Auxiliary function to estimate string length of subset list.  */
+
+static size_t
+riscv_estimate_arch_strlen1 (const riscv_subset_t *subset)
+{
+  if (subset == NULL)
+    return 6; /* For rv32/rv64/rv128 and string terminator.  */
+
+  return riscv_estimate_arch_strlen1 (subset->next)
+	 + strlen (subset->name)
+	 + riscv_estimate_digit (subset->major_version)
+	 + 1 /* For version seperator: 'p'.  */
+	 + riscv_estimate_digit (subset->minor_version)
+	 + 1 /* For underscore.  */;
+}
+
+/* Estimate the string length of this subset list.  */
+
+static size_t
+riscv_estimate_arch_strlen (const riscv_subset_list_t *subset_list)
+{
+  return riscv_estimate_arch_strlen1 (subset_list->head);
+}
+
+/* Auxiliary function to convert subset info to string.  */
+
+static void
+riscv_arch_str1 (riscv_subset_t *subset,
+		 char *attr_str, char *buf, size_t bufsz)
+{
+  const char *underline = "_";
+
+  if (subset == NULL)
+    return;
+
+  /* No underline between rvXX and i/e.   */
+  if ((strcasecmp (subset->name, "i") == 0)
+      || (strcasecmp (subset->name, "e") == 0))
+    underline = "";
+
+  snprintf (buf, bufsz, "%s%s%dp%d",
+	    underline,
+            subset->name,
+            subset->major_version,
+            subset->minor_version);
+
+  strncat (attr_str, buf, bufsz);
+
+  /* Skip 'i' extension after 'e'.  */
+  if ((strcasecmp (subset->name, "e") == 0)
+      && subset->next
+      && (strcasecmp (subset->next->name, "i") == 0))
+    riscv_arch_str1 (subset->next->next, attr_str, buf, bufsz);
+  else
+    riscv_arch_str1 (subset->next, attr_str, buf, bufsz);
+}
+
+/* Convert subset info to string with explicit version info.  */
+
+char *
+riscv_arch_str (unsigned xlen, const riscv_subset_list_t *subset)
+{
+  size_t arch_str_len = riscv_estimate_arch_strlen (subset);
+  char *attr_str = xmalloc (arch_str_len);
+  char *buf = xmalloc (arch_str_len);
+
+  snprintf (attr_str, arch_str_len, "rv%u", xlen);
+
+  riscv_arch_str1 (subset->head, attr_str, buf, arch_str_len);
+  free (buf);
+
+  return attr_str;
+}
diff --git a/bfd/elfxx-riscv.h b/bfd/elfxx-riscv.h
index 03b4484..19f7bd2 100644
--- a/bfd/elfxx-riscv.h
+++ b/bfd/elfxx-riscv.h
@@ -83,3 +83,6 @@ riscv_supported_std_ext (void);
 
 extern void
 riscv_release_subset_list (riscv_subset_list_t *);
+
+extern char *
+riscv_arch_str (unsigned, const riscv_subset_list_t *);