RISCV changes broke 32-bit --enable-targets=all

By the look of it, git commit 39ff0b812324 broke 32-bit host
--enable-targets=all binutils builds.

/usr/local/bin/ld: ../opcodes/.libs/libopcodes.a(riscv-dis.o): in function `parse_riscv_dis_option':
/home/alan/src/binutils-gdb/opcodes/riscv-dis.c:102: undefined reference to `riscv_get_priv_spec_class'
collect2: error: ld returned 1 exit status
Makefile:925: recipe for target 'objdump' failed

The problem is that elfxx-riscv.c is not built for a 32-bit host
without --enable-64-bit-bfd or unless RISCV is given specifically as a
target.  No such trimming of 64-bit only targets is done in opcodes.

One solution is to move these support functions to cpu-riscv.c, which
runs into "error: implicit declaration of function ‘xmalloc’".  Now,
xmalloc is not supposed to be used in libbfd or libopcodes - it's rude
to crash out of an application that calls libbfd or libopcodes
functions without giving it a chance to deal with out-of-memory
itself.  So I removed the xmalloc and instead used a fixed size
buffer.  If you are worried about adding 36 bytes for the buffer to
the riscv_get_priv_spec_class_from_numbers stack frame size, then you
have no idea of the likely xmalloc + malloc stack frame size!  Trying
to reduce memory usage is commendable, but in this instance
riscv_estimate_digit and malloc for a temp buffer uses a lot more
memory than a fixed max-size buffer.

	* elfxx-riscv.c (struct priv_spec_t, priv_specs),
	(riscv_get_priv_spec_class, riscv_get_priv_spec_class_from_numbers),
	(riscv_get_priv_spec_name): Move to..
	* cpu-riscv.c: ..here.
	(riscv_get_priv_spec_class_from_numbers): Don't xmalloc temp buffer.
	Use %u to print unsigned numbers.

bfd/ChangeLog

@@ -1,3 +1,12 @@
+2020-06-26  Alan Modra  <amodra@gmail.com>
+
+	* elfxx-riscv.c (struct priv_spec_t, priv_specs),
+	(riscv_get_priv_spec_class, riscv_get_priv_spec_class_from_numbers),
+	(riscv_get_priv_spec_name): Move to..
+	* cpu-riscv.c: ..here.
+	(riscv_get_priv_spec_class_from_numbers): Don't xmalloc temp buffer.
+	Use %u to print unsigned numbers.
+
 2020-06-24  Andrew Burgess  <andrew.burgess@embecosm.com>
 
 	* cpu-riscv.c (riscv_scan): Don't allow shorter matches using the

bfd/cpu-riscv.c

@@ -23,6 +23,86 @@
 #include "sysdep.h"
 #include "bfd.h"
 #include "libbfd.h"
+#include "elfxx-riscv.h"
+
+/* Record the priv spec version string and the corresponding class.  */
+
+struct priv_spec_t
+{
+  const char *name;
+  enum riscv_priv_spec_class class;
+};
+
+/* List for all supported privilege versions.  */
+
+static const struct priv_spec_t priv_specs[] =
+{
+  {"1.9.1", PRIV_SPEC_CLASS_1P9P1},
+  {"1.10",  PRIV_SPEC_CLASS_1P10},
+  {"1.11",  PRIV_SPEC_CLASS_1P11},
+
+/* Terminate the list.  */
+  {NULL, 0}
+};
+
+/* Get the corresponding CSR version class by giving a privilege
+   version string.  */
+
+int
+riscv_get_priv_spec_class (const char *s,
+			   enum riscv_priv_spec_class *class)
+{
+  const struct priv_spec_t *version;
+
+  if (s == NULL)
+    return 0;
+
+  for (version = &priv_specs[0]; version->name != NULL; ++version)
+    if (strcmp (version->name, s) == 0)
+      {
+	*class = version->class;
+	return 1;
+      }
+
+  /* Can not find the supported privilege version.  */
+  return 0;
+}
+
+/* Get the corresponding CSR version class by giving privilege
+   version numbers.  It is usually used to convert the priv
+   attribute numbers into the corresponding class.  */
+
+int
+riscv_get_priv_spec_class_from_numbers (unsigned int major,
+					unsigned int minor,
+					unsigned int revision,
+					enum riscv_priv_spec_class *class)
+{
+  char buf[36];
+
+  if (major == 0 && minor == 0 && revision == 0)
+    {
+      *class = PRIV_SPEC_CLASS_NONE;
+      return 1;
+    }
+
+  if (revision != 0)
+    snprintf (buf, sizeof (buf), "%u.%u.%u", major, minor, revision);
+  else
+    snprintf (buf, sizeof (buf), "%u.%u", major, minor);
+
+  return riscv_get_priv_spec_class (buf, class);
+}
+
+/* Get the corresponding privilege version string by giving a CSR
+   version class.  */
+
+const char *
+riscv_get_priv_spec_name (enum riscv_priv_spec_class class)
+{
+  /* The first enum is PRIV_SPEC_CLASS_NONE.  */
+  return priv_specs[class - 1].name;
+}
 
 /* This routine is provided two arch_infos and returns an arch_info
    that is compatible with both, or NULL if none exists.  */

bfd/elfxx-riscv.c

@@ -1749,98 +1749,3 @@ riscv_arch_str (unsigned xlen, const riscv_subset_list_t *subset)
 
   return attr_str;
 }
-
-/* Record the priv spec version string and the corresponding class.  */
-
-struct priv_spec_t
-{
-  const char *name;
-  enum riscv_priv_spec_class class;
-};
-
-/* List for all supported privilege versions.  */
-
-static const struct priv_spec_t priv_specs[] =
-{
-  {"1.9.1", PRIV_SPEC_CLASS_1P9P1},
-  {"1.10",  PRIV_SPEC_CLASS_1P10},
-  {"1.11",  PRIV_SPEC_CLASS_1P11},
-
-/* Terminate the list.  */
-  {NULL, 0}
-};
-
-/* Get the corresponding CSR version class by giving a privilege
-   version string.  */
-
-int
-riscv_get_priv_spec_class (const char *s,
-			   enum riscv_priv_spec_class *class)
-{
-  const struct priv_spec_t *version;
-
-  if (s == NULL)
-    return 0;
-
-  for (version = &priv_specs[0]; version->name != NULL; ++version)
-    if (strcmp (version->name, s) == 0)
-      {
-	*class = version->class;
-	return 1;
-      }
-
-  /* Can not find the supported privilege version.  */
-  return 0;
-}
-
-/* Get the corresponding CSR version class by giving privilege
-   version numbers.  It is usually used to convert the priv
-   attribute numbers into the corresponding class.  */
-
-int
-riscv_get_priv_spec_class_from_numbers (unsigned int major,
-					unsigned int minor,
-					unsigned int revision,
-					enum riscv_priv_spec_class *class)
-{
-  size_t buf_size;
-  char *buf;
-  int result = 1;
-
-  if (major == 0 && minor == 0 && revision == 0)
-    {
-      *class = PRIV_SPEC_CLASS_NONE;
-      return result;
-    }
-
-  buf_size = riscv_estimate_digit (major)
-	     + 1 /* '.' */
-	     + riscv_estimate_digit (minor)
-	     + 1; /* string terminator */
-  if (revision != 0)
-    {
-      buf_size += 1 /* '.' */
-		  + riscv_estimate_digit (revision);
-      buf = xmalloc (buf_size);
-      snprintf (buf, buf_size, "%d.%d.%d", major, minor, revision);
-    }
-  else
-    {
-      buf = xmalloc (buf_size);
-      snprintf (buf, buf_size, "%d.%d", major, minor);
-    }
-
-  result = riscv_get_priv_spec_class (buf, class);
-  free (buf);
-  return result;
-}
-
-/* Get the corresponding privilege version string by giving a CSR
-   version class.  */
-
-const char *
-riscv_get_priv_spec_name (enum riscv_priv_spec_class class)
-{
-  /* The first enum is PRIV_SPEC_CLASS_NONE.  */
-  return priv_specs[class - 1].name;
-}