[PATCH] fix py-inferior.exp for remote cross-endian testing

[Nathan Froyd <froydnj at codesourcery dot com>]

The patch below fixes a problem seen when doing remote testing on a
target that has a different endianness from the host.  Python's pack
function will pack according to host endianness, but the search_memory
function searches according to target endianness.  Searching for a value
from the former with the latter, then, does not work correctly.

The solution taken is to discover the target endianness early on using
'show endian' (the Python interface ought to have a method for this...)
and then use that knowledge to explicitly indicate what endianness
Python's pack function should use for multi-byte values.  Strictly
speaking, the change in the final hunk is unnecessary (endianness will
always match in native testing), but is done for completeness.

Tested with cross to powerpc-linux-gnu from i686-pc-linux-gnu.  OK to
commit?

-Nathan

	* gdb.python/py-inferior.exp: Pack values in target endianness.
---
 gdb/testsuite/gdb.python/py-inferior.exp |   25 ++++++++++++++++++-------
 1 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/gdb/testsuite/gdb.python/py-inferior.exp b/gdb/testsuite/gdb.python/py-inferior.exp
index 45f43a1..7998b92 100644
--- a/gdb/testsuite/gdb.python/py-inferior.exp
+++ b/gdb/testsuite/gdb.python/py-inferior.exp
@@ -34,6 +34,17 @@ clean_restart ${testfile}
 # Skip all tests if Python scripting is not enabled.
 if { [skip_python_tests] } { continue }
 
+gdb_test_multiple "show endian" "getting target endian" {
+    -re ".*little endian.*$gdb_prompt $" {
+        set python_pack_char "<"
+	# pass silently
+    }
+    -re ".*big endian.*$gdb_prompt $" {
+        set python_pack_char ">"
+	# pass silently
+    }
+}
+
 # The following tests require execution.
 
 if ![runto_main] then {
@@ -106,7 +117,7 @@ gdb_test "set int16_search_buf\[10\] = 0x1234" "" ""
 gdb_test "py search_buf = gdb.selected_frame ().read_var ('int16_search_buf')" "" ""
 gdb_test "py start_addr = search_buf.address" "" ""
 gdb_test "py length = search_buf.type.sizeof" "" ""
-gdb_test "py pattern = pack('H',0x1234)" "" \
+gdb_test "py pattern = pack('${python_pack_char}H',0x1234)" "" \
 
 gdb_test "py print gdb.inferiors()\[0\].search_memory (start_addr, length, pattern)" \
   "${one_pattern_found}" "find 16-bit pattern, with value pattern"
@@ -117,7 +128,7 @@ gdb_test "set int32_search_buf\[10\] = 0x12345678" "" ""
 gdb_test "py search_buf = gdb.selected_frame ().read_var ('int32_search_buf')" "" ""
 gdb_test "py start_addr = search_buf.address" "" ""
 gdb_test "py length = search_buf.type.sizeof" "" ""
-gdb_test "py pattern = pack('I',0x12345678)" "" \
+gdb_test "py pattern = pack('${python_pack_char}I',0x12345678)" "" \
 
 gdb_test "py print gdb.inferiors()\[0\].search_memory (start_addr, length, pattern)" \
   "${one_pattern_found}" "find 32-bit pattern, with python pattern"
@@ -128,7 +139,7 @@ gdb_test "set int64_search_buf\[10\] = 0xfedcba9876543210LL" "" ""
 gdb_test "py search_buf = gdb.selected_frame ().read_var ('int64_search_buf')" "" ""
 gdb_test "py start_addr = search_buf.address" "" ""
 gdb_test "py length = search_buf.type.sizeof" "" ""
-gdb_test "py pattern = pack('Q', 0xfedcba9876543210)" "" ""
+gdb_test "py pattern = pack('${python_pack_char}Q', 0xfedcba9876543210)" "" ""
 
 gdb_test "py print gdb.inferiors()\[0\].search_memory (start_addr, length, pattern)" \
   "${one_pattern_found}" "find 64-bit pattern, with value pattern"
@@ -141,8 +152,8 @@ gdb_test "set *(int32_t*) &search_buf\[13\] = 0x64646464" "" ""
 gdb_test "py search_buf = gdb.selected_frame ().read_var ('search_buf')" "" ""
 gdb_test "py start_addr = search_buf\[0\].address" "" ""
 gdb_test "py pattern1 = pack('B', 0x62)" "" ""
-gdb_test "py pattern2 = pack('H', 0x6363)" "" ""
-gdb_test "py pattern3 = pack('I', 0x64646464)" "" ""
+gdb_test "py pattern2 = pack('${python_pack_char}H', 0x6363)" "" ""
+gdb_test "py pattern3 = pack('${python_pack_char}I', 0x64646464)" "" ""
 
 gdb_test "py print gdb.inferiors()\[0\].search_memory (start_addr, 100, pattern1)" \
     "${one_pattern_found}" "find mixed-sized pattern"
@@ -161,7 +172,7 @@ gdb_test "set *(int32_t*) &search_buf\[0*${CHUNK_SIZE}+100\] = 0x12345678" "" ""
 gdb_test "set *(int32_t*) &search_buf\[1*${CHUNK_SIZE}+100\] = 0x12345678" "" ""
 gdb_test "py start_addr = gdb.selected_frame ().read_var ('search_buf')" "" ""
 gdb_test "py length = gdb.selected_frame ().read_var ('search_buf_size')" "" ""
-gdb_test "py pattern = pack('I', 0x12345678)" "" ""
+gdb_test "py pattern = pack('${python_pack_char}I', 0x12345678)" "" ""
 gdb_test "py first = gdb.inferiors()\[0\].search_memory (start_addr,length, pattern)" "" ""
 gdb_test "py print first" "${one_pattern_found}" "search spanning large range 1st result"
 gdb_test "py start_addr = first + 1"
@@ -175,7 +186,7 @@ gdb_test "py print third" "${pattern_not_found}" "search spanning large range 3r
 
 if [isnative] {
     gdb_test "set *(int32_t*) &search_buf\[${CHUNK_SIZE}-1\] = 0xfdb97531" "" ""
-    gdb_test "py pattern = pack('I', 0xfdb97531)" "" ""
+    gdb_test "py pattern = pack('${python_pack_char}I', 0xfdb97531)" "" ""
     gdb_test "py start_addr = gdb.selected_frame ().read_var ('search_buf')" "" ""
     gdb_test "py print gdb.inferiors()\[0\].search_memory (start_addr, length, pattern)" \
       "${one_pattern_found}" "find pattern straddling chunk boundary"
-- 
1.6.3.2