Use new to_xfer_partial interface in ctf and tfile target

This patch adjust both ctf and tfile target implementation of to_xfer_partial,
to return TARGET_XFER_E_UNAVAILABLE and set *XFERED_LEN if data is
unavailable.  Note that some code on xfer in exec.c can be shared, but
we can do it in a separate pass later.

gdb:

2014-02-23  Yao Qi  <yao@codesourcery.com>

	* exec.c (section_table_read_available_memory): New function.
	* exec.h (section_table_read_available_memory): Declare.
	* ctf.c (ctf_xfer_partial): Call
	section_table_read_available_memory.
	* tracefile-tfile.c (tfile_xfer_partial): Likewise.

1 files changed, 8 insertions, 0 deletions

diff --git a/gdb/exec.h b/gdb/exec.h
index 960c585..84dc40f 100644
--- a/gdb/exec.h
+++ b/gdb/exec.h
@@ -91,6 +91,14 @@ extern enum target_xfer_status
 				     struct target_section *,
 				     const char *);
 
+/* Read from mappable read-only sections of BFD executable files.
+   Similar to exec_read_partial_read_only, but return
+   TARGET_XFER_E_UNAVAILABLE if data is unavailable.  */
+
+extern enum target_xfer_status
+  section_table_read_available_memory (gdb_byte *readbuf, ULONGEST offset,
+				       ULONGEST len, ULONGEST *xfered_len);
+
 /* Set the loaded address of a section.  */
 extern void exec_set_section_address (const char *, int, CORE_ADDR);