Fix problem that alias can be defined or not depending on the order.

When an alias name starts with the name of another alias,
GDB was accepting to define the aliases in one order (short first, long after),
but refused it the other way around.

So, fix the logic to recognise an already existing alias by using
lookup_cmd_composition.

Also, this revealed a bug in lookup_cmd_composition:
when the searched command is a prefix command, lookup_cmd_composition
was not returning the fact that a command was found even if the
TEXT to parse was fully consumed.

gdb/ChangeLog
YYYY-MM-DD  Philippe Waroquiers  <philippe.waroquiers@skynet.be>

	* cli/cli-cmds.c (alias_command): Check for an existing alias
	using lookup_cmd_composition, as valid_command_p is too strict
	and forbids aliases that are the prefix of an existing alias
	or command.
	* cli/cli-decode.c (lookup_cmd_composition): Ensure a prefix
	command is properly recognised as a valid command.

gdb/testsuite/ChangeLog
2020-05-15  Philippe Waroquiers  <philippe.waroquiers@skynet.be>

	* gdb.base/alias.exp: Test aliases starting with a prefix of
	another alias.
This commit is contained in:
Philippe Waroquiers 2020-05-05 21:38:38 +02:00
parent 58e6ac7006
commit 0605465feb
5 changed files with 51 additions and 9 deletions

View file

@ -1694,8 +1694,29 @@ alias_command (const char *args, int from_tty)
/* ALIAS must not exist. */
std::string alias_string (argv_to_string (alias_argv, alias_argc));
alias = alias_string.c_str ();
if (valid_command_p (alias))
error (_("Alias already exists: %s"), alias);
{
cmd_list_element *alias_cmd, *prefix_cmd, *cmd;
if (lookup_cmd_composition (alias, &alias_cmd, &prefix_cmd, &cmd))
{
const char *alias_name = alias_argv[alias_argc-1];
/* If we found an existing ALIAS_CMD, check that the prefix differ or
the name differ. */
if (alias_cmd != nullptr
&& alias_cmd->prefix == prefix_cmd
&& strcmp (alias_name, alias_cmd->name) == 0)
error (_("Alias already exists: %s"), alias);
/* Check ALIAS differs from the found CMD. */
if (cmd->prefix == prefix_cmd
&& strcmp (alias_name, cmd->name) == 0)
error (_("Alias %s is the name of an existing command"), alias);
}
}
/* If ALIAS is one word, it is an alias for the entire COMMAND.
Example: alias spe = set print elements