Make target_read_alloc & al return vectors

This patch started by changing target_read_alloc_1 to return a
byte_vector, to avoid manual memory management (in target_read_alloc_1
and in the callers).  To communicate failures to the callers, it
actually returns a gdb::optional<gdb::byte_vector>.

Adjusting target_read_stralloc was a bit more tricky, since it wants to
return a buffer of char, and not gdb_byte.  Since you can't just cast a
gdb::byte_vector into a gdb::def_vector<char>, I made
target_read_alloc_1 templated, so both versions (that return vectors of
gdb_byte and char) are generated.  Since target_read_stralloc now
returns a gdb::char_vector instead of a gdb::unique_xmalloc_ptr<char>, a
few callers need to be adjusted.

gdb/ChangeLog:

	* common/byte-vector.h (char_vector): New type.
	* target.h (target_read_alloc): Return
	gdb::optional<byte_vector>.
	(target_read_stralloc): Return gdb::optional<char_vector>.
	(target_get_osdata): Return gdb::optional<char_vector>.
	* target.c (target_read_alloc_1): Templatize.  Replacement
	manual memory management with vector.
	(target_read_alloc): Change return type, adjust.
	(target_read_stralloc): Change return type, adjust.
	(target_get_osdata): Change return type, adjust.
	* auxv.c (struct auxv_info) <length>: Remove.
	<data>: Change type to gdb::optional<byte_vector>.
	(auxv_inferior_data_cleanup): Free auxv_info with delete.
	(get_auxv_inferior_data): Allocate auxv_info with new, adjust.
	(target_auxv_search): Adjust.
	(fprint_target_auxv): Adjust.
	* avr-tdep.c (avr_io_reg_read_command): Adjust.
	* linux-tdep.c (linux_spu_make_corefile_notes): Adjust.
	(linux_make_corefile_notes): Adjust.
	* osdata.c (get_osdata): Adjust.
	* remote.c (remote_get_threads_with_qxfer): Adjust.
	(remote_memory_map): Adjust.
	(remote_traceframe_info): Adjust.
	(btrace_read_config): Adjust.
	(remote_read_btrace): Adjust.
	(remote_pid_to_exec_file): Adjust.
	* solib-aix.c (solib_aix_get_library_list): Adjust.
	* solib-dsbt.c (decode_loadmap): Don't free buf.
	(dsbt_get_initial_loadmaps): Adjust.
	* solib-svr4.c (svr4_current_sos_via_xfer_libraries): Adjust.
	* solib-target.c (solib_target_current_sos): Adjust.
	* tracepoint.c (sdata_make_value): Adjust.
	* xml-support.c (xinclude_start_include): Adjust.
	(xml_fetch_content_from_file): Adjust.
	* xml-support.h (xml_fetch_another): Change return type.
	(xml_fetch_content_from_file): Change return type.
	* xml-syscall.c (xml_init_syscalls_info): Adjust.
	* xml-tdesc.c (file_read_description_xml): Adjust.
	(fetch_available_features_from_target): Change return type.
	(target_fetch_description_xml): Adjust.
	(target_read_description_xml): Adjust.

1 files changed, 19 insertions, 21 deletions

diff --git a/gdb/avr-tdep.c b/gdb/avr-tdep.c
index c44a3aa..2b9be5e 100644
--- a/gdb/avr-tdep.c
+++ b/gdb/avr-tdep.c
@@ -1549,21 +1549,15 @@ avr_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
 static void
 avr_io_reg_read_command (const char *args, int from_tty)
 {
-  LONGEST bufsiz = 0;
-  gdb_byte *buf;
-  const char *bufstr;
   char query[400];
-  const char *p;
   unsigned int nreg = 0;
   unsigned int val;
-  int i, j, k, step;
 
   /* Find out how many io registers the target has.  */
-  bufsiz = target_read_alloc (&current_target, TARGET_OBJECT_AVR,
-			      "avr.io_reg", &buf);
-  bufstr = (const char *) buf;
+  gdb::optional<gdb::byte_vector> buf
+    = target_read_alloc (&current_target, TARGET_OBJECT_AVR, "avr.io_reg");
 
-  if (bufsiz <= 0)
+  if (!buf)
     {
       fprintf_unfiltered (gdb_stderr,
 			  _("ERR: info io_registers NOT supported "
@@ -1571,36 +1565,42 @@ avr_io_reg_read_command (const char *args, int from_tty)
       return;
     }
 
+  const char *bufstr = (const char *) buf->data ();
+
   if (sscanf (bufstr, "%x", &nreg) != 1)
     {
       fprintf_unfiltered (gdb_stderr,
 			  _("Error fetching number of io registers\n"));
-      xfree (buf);
       return;
     }
 
-  xfree (buf);
-
   reinitialize_more_filter ();
 
   printf_unfiltered (_("Target has %u io registers:\n\n"), nreg);
 
   /* only fetch up to 8 registers at a time to keep the buffer small */
-  step = 8;
+  int step = 8;
 
-  for (i = 0; i < nreg; i += step)
+  for (int i = 0; i < nreg; i += step)
     {
       /* how many registers this round? */
-      j = step;
+      int j = step;
       if ((i+j) >= nreg)
         j = nreg - i;           /* last block is less than 8 registers */
 
       snprintf (query, sizeof (query) - 1, "avr.io_reg:%x,%x", i, j);
-      bufsiz = target_read_alloc (&current_target, TARGET_OBJECT_AVR,
-				  query, &buf);
+      buf = target_read_alloc (&current_target, TARGET_OBJECT_AVR, query);
+
+      if (!buf)
+        {
+          fprintf_unfiltered (gdb_stderr,
+			      _("ERR: error reading avr.io_reg:%x,%x\n"),
+			      i, j);
+          return;
+        }
 
-      p = (const char *) buf;
-      for (k = i; k < (i + j); k++)
+      const char *p = (const char *) buf->data ();
+      for (int k = i; k < (i + j); k++)
 	{
 	  if (sscanf (p, "%[^,],%x;", query, &val) == 2)
 	    {
@@ -1612,8 +1612,6 @@ avr_io_reg_read_command (const char *args, int from_tty)
 		break;
 	    }
 	}
-
-      xfree (buf);
     }
 }