[PATCH 08/10] Handle "show remote memory-write-packet-size" when not connected

Pedro Alves
2018-05-16T14:25:33Z

Currently "show remote memory-write-packet-size" says that the packet
size is limited to whatever is stored in the remote_state global, even
if not connected to a target.

When we get to support multiple instances of remote targets, there
won't be a remote_state global anymore, so that must be replaced by
something else.

Since it doesn't make sense to print the limit of the packet size of a
non-existing connection, this patch makes us say that the limit will
be further reduced when we connect.

The text is taken from the command's online help, which says:

"The actual limit is further reduced dependent on the target."

gdb/ChangeLog:
yyyy-mm-dd Pedro Alves <palves@redhat.com>

* remote.c (get_fixed_memory_packet_size): New.
(get_memory_packet_size): Use it.
(show_memory_packet_size): Use it. Don't refer to
get_memory_packet_size if not connected to a remote target.

gdb/testsuite/ChangeLog:
yyyy-mm-dd Pedro Alves <palves@redhat.com>

* gdb.base/remote.exp: Adjust expected output of "show remote
memory-write-packet-size".
---
gdb/remote.c | 34 +++++++++++++++++++++++++---------
gdb/testsuite/gdb.base/remote.exp | 6 +++---
2 files changed, 28 insertions(+), 12 deletions(-)

diff --git a/gdb/remote.c b/gdb/remote.c
index 230288b727..7ec8d24a3b 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -1333,6 +1333,19 @@ struct memory_packet_config
can write at least one byte. */
#define MIN_MEMORY_PACKET_SIZE 20

+/* Get the memory packet size, assuming it is fixed. */
+
+static long
+get_fixed_memory_packet_size (struct memory_packet_config *config)
+{
+ gdb_assert (config->fixed_p);
+
+ if (config->size <= 0)
+ return DEFAULT_MAX_MEMORY_PACKET_SIZE;
+ else
+ return config->size;
+}
+
/* Compute the current size of a read/write packet. Since this makes
use of ``actual_register_packet_size'' the computation is dynamic. */

@@ -1344,12 +1357,7 @@ get_memory_packet_size (struct memory_packet_config *config)

long what_they_get;
if (config->fixed_p)
- {
- if (config->size <= 0)
- what_they_get = DEFAULT_MAX_MEMORY_PACKET_SIZE;
- else
- what_they_get = config->size;
- }
+ what_they_get = get_fixed_memory_packet_size (config);
else
{
what_they_get = get_remote_packet_size ();
@@ -1432,10 +1440,18 @@ show_memory_packet_size (struct memory_packet_config *config)
printf_filtered (_("The %s is %ld. "), config->name, config->size);
if (config->fixed_p)
printf_filtered (_("Packets are fixed at %ld bytes.\n"),
- get_memory_packet_size (config));
+ get_fixed_memory_packet_size (config));
else
- printf_filtered (_("Packets are limited to %ld bytes.\n"),
- get_memory_packet_size (config));
+ {
+ struct remote_state *rs = get_remote_state ();
+
+ if (rs->remote_desc != NULL)
+ printf_filtered (_("Packets are limited to %ld bytes.\n"),
+ get_memory_packet_size (config));
+ else
+ puts_filtered ("The actual limit will be further reduced "
+ "dependent on the target.\n");
+ }
}

static struct memory_packet_config memory_write_packet_config =
diff --git a/gdb/testsuite/gdb.base/remote.exp b/gdb/testsuite/gdb.base/remote.exp
index 26361af9a5..4f0eb10ea4 100644
--- a/gdb/testsuite/gdb.base/remote.exp
+++ b/gdb/testsuite/gdb.base/remote.exp
@@ -35,7 +35,7 @@ if {$result != "" } then {
#

gdb_test "show remote memory-write-packet-size" \
- "The memory-write-packet-size is 0. Packets are limited to \[0-9\]+ bytes." \
+ "The memory-write-packet-size is 0. The actual limit will be further reduced dependent on the target\." \
"write-packet default"

gdb_test "set remote memory-write-packet-size" \
@@ -44,12 +44,12 @@ gdb_test "set remote memory-write-packet-size" \

gdb_test_no_output "set remote memory-write-packet-size 20"
gdb_test "show remote memory-write-packet-size" \
- "The memory-write-packet-size is 20. Packets are limited to 20 bytes." \
+ "The memory-write-packet-size is 20. The actual limit will be further reduced dependent on the target\." \
"set write-packet - small"

gdb_test_no_output "set remote memory-write-packet-size 1"
gdb_test "show remote memory-write-packet-size" \
- "The memory-write-packet-size is 1. Packets are limited to 20 bytes." \
+ "The memory-write-packet-size is 1. The actual limit will be further reduced dependent on the target\." \
"set write-packet - very-small"

#
--
2.14.3