Fix break on Python 2

This changes the return type of "gdb.BtraceInstruction.data ()" from
"memoryview" to "buffer" on Python 2.7 and below, similar to what
"gdb.Inferior.read_memory ()" does.

gdb/ChangeLog

@@ -1,3 +1,8 @@
+2017-03-21  Tim Wiederhake  <tim.wiederhake@intel.com>
+
+	* python/py-record-btrace.c (btpy_insn_data): Change return type
+	for Python 2.
+
 2017-03-20  Simon Marchi  <simon.marchi@polymtl.ca>
 
 	* spu-linux-nat.c (spu_fetch_inferior_registers,

gdb/doc/ChangeLog

@@ -1,3 +1,8 @@
+2017-03-21  Tim Wiederhake  <tim.wiederhake@intel.com>
+
+	* python.texi (Recordings In Python): Document return type of
+	gdb.BtraceInstruction.data.
+
 2017-03-20  Marc-Andre Laperle  <marc-andre.laperle@ericsson.com>
 
 	* gdb.texinfo (gdb/mi Symbol Query Commands): Document new MI

gdb/doc/python.texi

@@ -3185,7 +3185,8 @@ if the instruction is a gap or the debug symbols could not be read.
 
 @defvar BtraceInstruction.data
 A buffer with the raw instruction data.  May be @code{None} if the
-instruction is a gap.
+instruction is a gap.  In Python 3, the return value is a @code{memoryview}
+object.
 @end defvar
 
 @defvar BtraceInstruction.decoded

gdb/python/py-record-btrace.c

@@ -330,7 +330,12 @@ btpy_insn_data (PyObject *self, void *closure)
   if (object == NULL)
     return NULL;
 
+#ifdef IS_PY3K
   return PyMemoryView_FromObject (object);
+#else
+  return PyBuffer_FromObject (object, 0, Py_END_OF_BUFFER);
+#endif
+
 }
 
 /* Implementation of BtraceInstruction.decode [str].  Returns

gdb/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2017-03-21  Tim Wiederhake  <tim.wiederhake@intel.com>
+
+	* gdb.python/py-record-btrace.exp: Check for buffer on Python 2
+	and memory view on Python 3.
+
 2017-03-20  Artemiy Volkov  <artemiyv@acm.org>
 	    Keith Seitz  <keiths@redhat.com>
 

gdb/testsuite/gdb.python/py-record-btrace.exp

@@ -85,7 +85,11 @@ with_test_prefix "instruction " {
     gdb_test "python print(i.error)" "None"
     gdb_test "python print(i.sal)" "symbol and line for .*"
     gdb_test "python print(i.pc)" "$decimal"
-    gdb_test "python print(i.data)" "<memory at $hex>"
+    if { $gdb_py_is_py3k == 0 } {
+	gdb_test "python print(repr(i.data))" "<read-only buffer for $hex,.*>"
+    } else {
+	gdb_test "python print(repr(i.data))" "<memory at $hex>"
+    }
     gdb_test "python print(i.decoded)" ".*"
     gdb_test "python print(i.size)" "$decimal"
     gdb_test "python print(i.is_speculative)" "False"