gdb: give deprecated command warning for aliases with a prefix

I noticed that deprecated aliases that have a prefix don't give a
deprecated command warning.  For example looking in mi/mi-main.c we
see this:

  c = add_alias_cmd ("target-async", "mi-async", class_run, 0, &setlist);
  deprecate_cmd (c, "set mi-async");
  c = add_alias_cmd ("target-async", "mi-async", class_run, 0, &showlist);
  deprecate_cmd (c, "show mi-async");

So both 'set target-async' and 'show target-async' are deprecated and
should be giving a warning, however, in use we see no warning given.

This is a consequence of how the code that should give this
warning (deprecated_cmd_warning) performs a second command lookup in
order to distinguish between aliases and real commands, and that the
code that calls this (lookup_cmd_1) strips off prefix commands as it
calls itself recursively.

As a result when we are considering an alias like 'set target-async'
we first enter lookup_cmd_1 with text = "set target-async", we spot
the 'set' command prefix and then recursively call lookup_cmd_1 with
text = "target-async".

We spot that 'target-async' is a known alias but that it is
deprecated, and so call deprecated_cmd_warning passing in the value of
text, which remember is now "target-async".

In deprecated_cmd_warning we again perform a command lookup starting
from the top-level cmdlist, but now we're trying to find just
"target-async", this fails (as this command requires the 'set' prefix,
and so no warning is given.

I resolved this issue by passing a command list to the function
deprecated_cmd_warning, this is the list in which the command can be
found.

A new test is added to cover this case.

However, there is an additional problem which will be addressed in a
subsequent patch.

Consider this GDB session:

  (gdb) define set xxx_yyy
  Type commands for definition of "set xxx_yyy".
  End with a line saying just "end".
  >echo in set xxx_yyy command\n
  >end
  (gdb) alias set qqq_aaa=set xxx_yyy
  (gdb) maintenance deprecate set qqq_aaa
  (gdb) set qqq_aaa
  Warning: 'qqq_aaa', an alias for the command 'xxx_yyy' is deprecated.
  No alternative known.

  in set xxx_yyy command
  (gdb)

Notice the warning mentions 'qqq_aaa' and 'xxx_yyy', I consider this
to be wrong.  I think the proper warning should read:

  (gdb) set qqq_aaa
  Warning: 'set qqq_aaa', an alias for the command 'set xxx_yyy' is deprecated.
  No alternative known.

With the 'set' prefixes added.  A later patch will resolve this
issue.

gdb/ChangeLog:

	PR cli/15104
	* cli/cli-decode.c (lookup_cmd_1): Pass command list to
	deprecated_cmd_warning.
	(deprecated_cmd_warning): Take extra parameter, call
	lookup_cmd_composition_1 and pass new parameter through.
	(lookup_cmd_composition_1): New function, takes implementation of
	lookup_cmd_composition but with extra parameter.
	(lookup_cmd_composition): Now calls lookup_cmd_composition_1
	passing in cmdlist.
	* command.h (deprecated_cmd_warning): Add extra parameter to
	declaration.
	* top.c (execute_command): Pass cmdlist to deprecated_cmd_warning.

gdb/testsuite/ChangeLog:

	PR cli/15104
	* gdb.base/commands.exp: Add additional tests.
	* gdb.base/completion.exp: Add additional tests.

1 files changed, 7 insertions, 0 deletions

diff --git a/gdb/testsuite/gdb.base/completion.exp b/gdb/testsuite/gdb.base/completion.exp
index 14d56a5..8000d52 100644
--- a/gdb/testsuite/gdb.base/completion.exp
+++ b/gdb/testsuite/gdb.base/completion.exp
@@ -968,3 +968,10 @@ foreach_with_prefix cmd { "watch" "awatch" "rwatch" } {
 gdb_test_no_output "alias xxx_yyy_zzz=break"
 gdb_test_no_output "maint deprecate xxx_yyy_zzz"
 test_gdb_complete_unique "xxx_yyy_" "xxx_yyy_zzz"
+
+# Check that tab completion of a deprecated alias with a prefix does
+# not display the warning about the alias being deprecated during tab
+# completion.
+gdb_test_no_output "alias set aaa_bbb_ccc=set debug"
+gdb_test_no_output "maint deprecate set aaa_bbb_ccc"
+test_gdb_complete_unique "set aaa_bbb_" "set aaa_bbb_ccc"