OpenE2K
/
binutils-gdb
12
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Handle "show remote memory-write-packet-size" when not connected 

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."

Note that a value of "0" is special, as per "help set remote
memory-write-packet-size":

 ~~~
 Specify the number of bytes in a packet or 0 (zero) for the
 default packet size.
 ~~~

I've tweaked "show remote memory-write-packet-size" to include
"(default)" in the output in that case, like this:

 (gdb) show remote memory-write-packet-size
 The memory-write-packet-size is 0 (default). The actual limit will be further reduced dependent on the target.

While working on this, I noticed that an explicit "set remote
write-packet-size 0" does not makes GDB go back to the exact same
state as the default state when GDB starts up:

 (gdb) show remote memory-write-packet-size
 The memory-write-packet-size is 0. [...]
                                 ^^

 (gdb) set remote memory-write-packet-size 0
 (gdb) show remote memory-write-packet-size
 The memory-write-packet-size is 16384. [...]
                                 ^^^^^

The "16384" number comes from DEFAULT_MAX_MEMORY_PACKET_SIZE.

This happens because git commit a5c0808e22 ("gdb: remove packet size
limit") at
<https://sourceware.org/ml/gdb-patches/2015-08/msg00743.html>, added
this:

  /* So that the query shows the correct value.  */
  if (size <= 0)
    size = DEFAULT_MAX_MEMORY_PACKET_SIZE;

to set_memory_packet_size, but despite what the comment suggests, that
also has the side-effect of recording DEFAULT_MAX_MEMORY_PACKET_SIZE
in config->size.

Finally, DEFAULT_MAX_MEMORY_PACKET_SIZE only makes sense for "set
remote memory-write-packet-size fixed", so I've renamed it
accordingly, to make it a little bit clearer.

gdb/ChangeLog:
2018-05-22  Pedro Alves  <palves@redhat.com>

	* remote.c (DEFAULT_MAX_MEMORY_PACKET_SIZE): Rename to ...
	(DEFAULT_MAX_MEMORY_PACKET_SIZE_FIXED): ... this.
	(get_fixed_memory_packet_size): New.
	(get_memory_packet_size): Use it.
	(set_memory_packet_size): Don't override the config size with
	DEFAULT_MAX_MEMORY_PACKET_SIZE.
	(show_memory_packet_size): Use get_fixed_memory_packet_size.
	Don't refer to get_memory_packet_size if not connected to a remote
	target.  Show "(default)" if configured size is 0.

gdb/testsuite/ChangeLog:
2018-05-22  Pedro Alves  <palves@redhat.com>

	* gdb.base/remote.exp: Adjust expected output of "show remote
	memory-write-packet-size".  Add tests for "set remote
	memory-write-packet-size 0" and "set remote
	memory-write-packet-size fixed/limit".
This commit is contained in:
Pedro Alves 2018-05-22 18:22:10 +01:00
parent 9607784ac0
commit cc0be08f80
4 changed files with 86 additions and 23 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
gdb/ChangeLog
View File

@ -1,3 +1,15 @@
2018-05-22 Pedro Alves <palves@redhat.com>
* remote.c (DEFAULT_MAX_MEMORY_PACKET_SIZE): Rename to ...
(DEFAULT_MAX_MEMORY_PACKET_SIZE_FIXED): ... this.
(get_fixed_memory_packet_size): New.
(get_memory_packet_size): Use it.
(set_memory_packet_size): Don't override the config size with
DEFAULT_MAX_MEMORY_PACKET_SIZE.
(show_memory_packet_size): Use get_fixed_memory_packet_size.
Don't refer to get_memory_packet_size if not connected to a remote
target. Show "(default)" if configured size is 0.
2018-05-22 Pedro Alves <palves@redhat.com>
* remote.c (remote_target::mourn_inferior): Move

60
gdb/remote.c
View File

@ -1328,16 +1328,29 @@ struct memory_packet_config
int fixed_p;
};
/* The default max memory-write-packet-size. The 16k is historical.
(It came from older GDB's using alloca for buffers and the
knowledge (folklore?) that some hosts don't cope very well with
large alloca calls.) */
#define DEFAULT_MAX_MEMORY_PACKET_SIZE 16384
/* The default max memory-write-packet-size, when the setting is
"fixed". The 16k is historical. (It came from older GDB's using
alloca for buffers and the knowledge (folklore?) that some hosts
don't cope very well with large alloca calls.) */
#define DEFAULT_MAX_MEMORY_PACKET_SIZE_FIXED 16384
/* The minimum remote packet size for memory transfers. Ensures we
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_FIXED;
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. */
@ -1349,12 +1362,7 @@ 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 ();
@ -1414,16 +1422,17 @@ set_memory_packet_size (const char *args, struct memory_packet_config *config)
something arbitrarily large. */
}
/* So that the query shows the correct value. */
if (size <= 0)
size = DEFAULT_MAX_MEMORY_PACKET_SIZE;
/* Extra checks? */
if (fixed_p && !config->fixed_p)
{
/* So that the query shows the correct value. */
long query_size = (size <= 0
? DEFAULT_MAX_MEMORY_PACKET_SIZE_FIXED
: size);
if (! query (_("The target may not be able to correctly handle a %s\n"
"of %ld bytes. Change the packet size? "),
config->name, size))
config->name, query_size))
error (_("Packet size not changed."));
}
/* Update the config. */
@ -1434,13 +1443,24 @@ set_memory_packet_size (const char *args, struct memory_packet_config *config)
static void
show_memory_packet_size (struct memory_packet_config *config)
{
printf_filtered (_("The %s is %ld. "), config->name, config->size);
if (config->size == 0)
printf_filtered (_("The %s is 0 (default). "), config->name);
else
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 =

7
gdb/testsuite/ChangeLog
View File

@ -1,3 +1,10 @@
2018-05-22 Pedro Alves <palves@redhat.com>
* gdb.base/remote.exp: Adjust expected output of "show remote
memory-write-packet-size". Add tests for "set remote
memory-write-packet-size 0" and "set remote
memory-write-packet-size fixed/limit".
2018-05-22 Pedro Alves <palves@redhat.com>
PR gdb/22973

30
gdb/testsuite/gdb.base/remote.exp
View File

@ -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 \\(default\\). The actual limit will be further reduced dependent on the target\." \
"write-packet default"
gdb_test "set remote memory-write-packet-size" \
@ -44,14 +44,38 @@ 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"
gdb_test_no_output "set remote memory-write-packet-size 0"
gdb_test "show remote memory-write-packet-size" \
"The memory-write-packet-size is 0 \\(default\\). The actual limit will be further reduced dependent on the target\." \
"write-packet default again"
set test "set remote memory-write-packet-size fixed"
gdb_test_multiple $test $test {
-re "Change the packet size. .y or n. " {
gdb_test_multiple "y" $test {
-re "$gdb_prompt $" {
pass $test
}
}
}
}
gdb_test "show remote memory-write-packet-size" \
"The memory-write-packet-size is 0 \\(default\\). Packets are fixed at 16384 bytes\." \
"write-packet default fixed"
gdb_test_no_output "set remote memory-write-packet-size limit"
gdb_test "show remote memory-write-packet-size" \
"The memory-write-packet-size is 0 \\(default\\). The actual limit will be further reduced dependent on the target\." \
"write-packet default limit again"
#
# Part TWO: Check the download behavior.
#