[Patch Darwin] head build fixes for i686-darwin9/x86_64-darwin10.

[Iain Sandoe <developer@sandoe-acoustics.co.uk>]

Hi,
At present trunk gdb does not build for me on either i686-darwin9 or  
x86_64-darwin10.

There are two problems on Darwin 10 and three on Darwin 9 (description  
with each patchlet, below).

OK?
Iain

gdb:

	* machoread.c (macho_symtab_read): Initialize nbr_syms.
	* i386-darwin-nat.c (DR_FIRSTADDR, DR_LASTADDR, DR_STATUS,
	DR_CONTROL): Ensure a default definition is available.
	* darwin-nat.c (darwin_read_dyld_info): Only build if
	TASK_DYLD_INFO_COUNT is available.
	(darwin_xfer_partial): Don not try to fetch dyld info
	unless TASK_DYLD_INFO_COUNT is available.

=====

1/ a "maybe used un-initialized" (in machoread.c)

which is fixed thus:

diff --git a/gdb/machoread.c b/gdb/machoread.c
index 46b8842..ba38ca6 100644
--- a/gdb/machoread.c
+++ b/gdb/machoread.c
@@ -180,7 +180,7 @@ macho_symtab_read (struct objfile *objfile,
    const asymbol *dir_so = NULL;
    const asymbol *file_so = NULL;
    asymbol **oso_file = NULL;
-  unsigned int nbr_syms;
+  unsigned int nbr_syms = 0;

    /* Current state while reading stabs.  */
    enum

=======

2/ DR_FIRSTADDR and cousins are undefined.
(the fragment below is copied verbatim from gdb-7.3.1 - is there some  
reason to expect that it should have been defined elsewhere?)

diff --git a/gdb/i386-darwin-nat.c b/gdb/i386-darwin-nat.c
index 23f6a6d..2a346c4 100644
--- a/gdb/i386-darwin-nat.c
+++ b/gdb/i386-darwin-nat.c
@@ -263,6 +263,22 @@ i386_darwin_store_inferior_registers (struct  
target_ops *ops,

  /* Support for debug registers, boosted mostly from i386-linux- 
nat.c.  */

+#ifndef DR_FIRSTADDR
+#define DR_FIRSTADDR 0
+#endif
+
+#ifndef DR_LASTADDR
+#define DR_LASTADDR 3
+#endif
+
+#ifndef DR_STATUS
+#define DR_STATUS 6
+#endif
+
+#ifndef DR_CONTROL
+#define DR_CONTROL 7
+#endif
+
  static void
  i386_darwin_dr_set (int regnum, uint32_t value)
  {

=====

3/ (Darwin 9 only)
TASK_DYLD_INFO_COUNT etc. are not defined.

Fixed thus:
diff --git a/gdb/darwin-nat.c b/gdb/darwin-nat.c
index 94f49d6..efc59e7 100644
--- a/gdb/darwin-nat.c
+++ b/gdb/darwin-nat.c
@@ -1823,6 +1823,7 @@ out:
    return length;
  }

+#ifdef TASK_DYLD_INFO_COUNT
  /* Read LENGTH bytes at offset ADDR of task_dyld_info for TASK, and  
copy them
     to RDADDR.
     Return 0 on failure; number of bytes read / writen otherwise.  */
@@ -1848,7 +1849,7 @@ darwin_read_dyld_info (task_t task, CORE_ADDR  
addr, char *rdaddr, int length)
    memcpy (rdaddr, (char *)&task_dyld_info + addr, length);
    return length;
  }
-
+#endif
  \f
  /* Return 0 on failure, number of bytes handled otherwise.  TARGET
     is ignored.  */
@@ -1890,6 +1891,7 @@ darwin_xfer_partial (struct target_ops *ops,
      case TARGET_OBJECT_MEMORY:
        return darwin_read_write_inferior (inf->private->task, offset,
                                           readbuf, writebuf, len);
+#ifdef TASK_DYLD_INFO_COUNT
      case TARGET_OBJECT_DARWIN_DYLD_INFO:
        if (writebuf != NULL || readbuf == NULL)
          {
@@ -1897,6 +1899,7 @@ darwin_xfer_partial (struct target_ops *ops,
            return -1;
          }
        return darwin_read_dyld_info (inf->private->task, offset,  
readbuf, len);
+#endif
      default:
        return -1;
      }