Re: Python: fetch value when building gdb.Value object

Jan Kratochvil
2011-10-01T11:03:16Z

On Sat, 01 Oct 2011 12:22:46 +0200, Pedro Alves wrote:
> On Saturday 01 October 2011 10:28:52, Jan Kratochvil wrote:
> > # Test memory error.
> > gdb_test "python print gdb.parse_and_eval('*(int*)0')" "gdb.MemoryError: Cannot access memory at address 0x0.*"
> > + gdb_test "python inval = gdb.parse_and_eval('*(int*)0')" "gdb.MemoryError: Cannot access memory at address 0x0.*"
>
> I see this is already the case, but just a reminder that this will fail
> (or rather the write will succeed) on targets without an MMU. We should
> skip it with something like:

So checked it in (I am aware the existing code elsewhere in GDB testsuite is
a bit different).

Thanks,
Jan

http://sourceware.org/ml/gdb-cvs/2011-10/msg00002.html

--- src/gdb/testsuite/ChangeLog 2011/09/30 15:07:32 1.2867
+++ src/gdb/testsuite/ChangeLog 2011/10/01 11:02:10 1.2868
@@ -1,3 +1,12 @@
+2011-10-01 Jan Kratochvil <jan.kratochvil@redhat.com>
+ Pedro Alves <pedro@codesourcery.com>
+
+ * gdb.python/py-value.exp (test_value_in_inferior): New variable
+ can_read_0, test for it.
+ (python print gdb.parse_and_eval('*(int*)0')): Rename to ...
+ (parse_and_eval with memory error): ... here, make it untested if
+ can_read_0.
+
2011-09-30 Marek Polacek <mpolacek@redhat.com>

* gdb.python/python.exp (verify pagination beforehand)
--- src/gdb/testsuite/gdb.python/py-value.exp 2011/07/26 18:38:55 1.22
+++ src/gdb/testsuite/gdb.python/py-value.exp 2011/10/01 11:02:11 1.23
@@ -216,8 +216,25 @@
# Test address attribute
gdb_test "python print 'result =', arg0.address" "= 0x\[\[:xdigit:\]\]+" "Test address attribute"

+ # Test displaying a variable that is temporarily at a bad address.
+ # But if we can examine what's at memory address 0, then we'll also be
+ # able to display it without error. Don't run the test in that case.
+ set can_read_0 0
+ gdb_test_multiple "x 0" "memory at address 0" {
+ -re "0x0:\[ \t\]*Cannot access memory at address 0x0\r\n$gdb_prompt $" { }
+ -re "0x0:\[ \t\]*Error accessing memory address 0x0\r\n$gdb_prompt $" { }
+ -re "\r\n$gdb_prompt $" {
+ set can_read_0 1
+ }
+ }
+
# Test memory error.
- gdb_test "python print gdb.parse_and_eval('*(int*)0')" "gdb.MemoryError: Cannot access memory at address 0x0.*"
+ set test "parse_and_eval with memory error"
+ if {$can_read_0} {
+ untested $test
+ } else {
+ gdb_test "python print gdb.parse_and_eval('*(int*)0')" "gdb.MemoryError: Cannot access memory at address 0x0.*" $test
+ }

# Test string fetches, both partial and whole.
gdb_test "print st" "\"divide et impera\""