Re: [RFA] completion in command definition

Jerome Guitton
2017-01-31T15:29:21Z

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Pedro Alves (palves@redhat.com):

> A few minor comments below.

Thanks again! Comments integrated. I'm just not sure about this one:

> > +
> > + gdb_test "info break \$bpnum" \
> > + "Num Type\[ \]+Disp Enb Address\[ \]+What.*
> > +\[0-9\]+\[\t \]+breakpoint keep y.* in main at .*
> > +\[\t \]+echo.*"
>
> I think we need to use use multi_line, to avoid problems with
> "\n" vs "\r" vs "\r\n".

I've used the same code pattern as in break.exp; is that OK?

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commit 1f892fe4947beee9879a4e04b93ce46acf591b8b
Author: Jerome Guitton <guitton@adacore.com>
Date: Tue Jan 10 15:15:53 2017 +0100

Command abbreviation in define

When defining a new macro, "command" is not recognized as an alias for
"commands":

(gdb) define breakmain
Type commands for definition of "breakmain".
End with a line saying just "end".
>break main
>command
>echo "IN MAIN\n"
>end
(gdb)

There is a special case for while-stepping, where 'ws' and 'stepping' are
recognized explicitely. Instead of adding more special cases, this change
uses cli-decode.

gdb/ChangeLog:
* cli/cli-decode.c (find_command_name_length): Make it extern.
* cli/cli-decode.h (find_command_name_length): Declare.
* cli/cli-script.c (command_name_equals, line_first_arg):
New functions.
(process_next_line): Use cli-decode to parse command names.
(build_command_line): Make args a constant pointer.

gdb/testsuite/ChangeLog:

* gdb.base/define.exp: Add test for command abbreviations
in define.

diff --git a/gdb/cli/cli-decode.c b/gdb/cli/cli-decode.c
index d3be93c..9312177 100644
--- a/gdb/cli/cli-decode.c
+++ b/gdb/cli/cli-decode.c
@@ -1255,7 +1255,9 @@ find_cmd (const char *command, int len, struct cmd_list_element *clist,
return found;
}

-static int
+/* Return the length of command name in TEXT. */
+
+int
find_command_name_length (const char *text)
{
const char *p = text;
diff --git a/gdb/cli/cli-decode.h b/gdb/cli/cli-decode.h
index e5ab839..66159fd 100644
--- a/gdb/cli/cli-decode.h
+++ b/gdb/cli/cli-decode.h
@@ -253,4 +253,6 @@ extern const char * const auto_boolean_enums[];

extern int cli_user_command_p (struct cmd_list_element *);

+extern int find_command_name_length (const char *);
+
#endif /* !defined (CLI_DECODE_H) */
diff --git a/gdb/cli/cli-script.c b/gdb/cli/cli-script.c
index 6f44d52..c3f1c65 100644
--- a/gdb/cli/cli-script.c
+++ b/gdb/cli/cli-script.c
@@ -143,7 +143,7 @@ multi_line_command_p (enum command_control_type type)
control commands (if/while). */

static struct command_line *
-build_command_line (enum command_control_type type, char *args)
+build_command_line (enum command_control_type type, const char *args)
{
struct command_line *cmd;

@@ -904,6 +904,27 @@ read_next_line (void)
return command_line_input (prompt_ptr, from_tty, "commands");
}

+/* Return true if CMD's name is NAME. */
+
+static bool
+command_name_equals (struct cmd_list_element *cmd, const char *name)
+{
+ return (cmd != NULL
+ && cmd != CMD_LIST_AMBIGUOUS
+ && strcmp (cmd->name, name) == 0);
+}
+
+/* Given an input line P, skip the command and return a pointer to the
+ first argument. */
+
+static const char *
+line_first_arg (const char *p)
+{
+ const char *first_arg = p + find_command_name_length (p);
+
+ return skip_spaces_const (first_arg);
+}
+
/* Process one input line. If the command is an "end", return such an
indication to the caller. If PARSE_COMMANDS is true, strip leading
whitespace (trailing whitespace is always stripped) in the line,
@@ -938,9 +959,14 @@ process_next_line (char *p, struct command_line **command, int parse_commands,
We also permit whitespace before end and after. */
if (p_end - p_start == 3 && startswith (p_start, "end"))
return end_command;
-
+
if (parse_commands)
{
+ /* Resolve command abbreviations (e.g. 'ws' for 'while-stepping'). */
+ const char *cmd_name = p;
+ struct cmd_list_element *cmd
+ = lookup_cmd_1 (&cmd_name, cmdlist, NULL, 1);
+
/* If commands are parsed, we skip initial spaces. Otherwise,
which is the case for Python commands and documentation
(see the 'document' command), spaces are preserved. */
@@ -958,9 +984,7 @@ process_next_line (char *p, struct command_line **command, int parse_commands,

/* Check for while, if, break, continue, etc and build a new
command line structure for them. */
- if ((p_end - p >= 14 && startswith (p, "while-stepping"))
- || (p_end - p >= 8 && startswith (p, "stepping"))
- || (p_end - p >= 2 && startswith (p, "ws")))
+ if (command_name_equals (cmd, "while-stepping"))
{
/* Because validate_actionline and encode_action lookup
command's line as command, we need the line to
@@ -975,40 +999,25 @@ process_next_line (char *p, struct command_line **command, int parse_commands,
not. */
*command = build_command_line (while_stepping_control, p);
}
- else if (p_end - p > 5 && startswith (p, "while"))
+ else if (command_name_equals (cmd, "while"))
{
- char *first_arg;
-
- first_arg = p + 5;
- while (first_arg < p_end && isspace (*first_arg))
- first_arg++;
- *command = build_command_line (while_control, first_arg);
+ *command = build_command_line (while_control, line_first_arg (p));
}
- else if (p_end - p > 2 && startswith (p, "if"))
+ else if (command_name_equals (cmd, "if"))
{
- char *first_arg;
-
- first_arg = p + 2;
- while (first_arg < p_end && isspace (*first_arg))
- first_arg++;
- *command = build_command_line (if_control, first_arg);
+ *command = build_command_line (if_control, line_first_arg (p));
}
- else if (p_end - p >= 8 && startswith (p, "commands"))
+ else if (command_name_equals (cmd, "commands"))
{
- char *first_arg;
-
- first_arg = p + 8;
- while (first_arg < p_end && isspace (*first_arg))
- first_arg++;
- *command = build_command_line (commands_control, first_arg);
+ *command = build_command_line (commands_control, line_first_arg (p));
}
- else if (p_end - p == 6 && startswith (p, "python"))
+ else if (command_name_equals (cmd, "python"))
{
/* Note that we ignore the inline "python command" form
here. */
*command = build_command_line (python_control, "");
}
- else if (p_end - p == 6 && startswith (p, "compile"))
+ else if (command_name_equals (cmd, "compile"))
{
/* Note that we ignore the inline "compile command" form
here. */
@@ -1016,7 +1025,7 @@ process_next_line (char *p, struct command_line **command, int parse_commands,
(*command)->control_u.compile.scope = COMPILE_I_INVALID_SCOPE;
}

- else if (p_end - p == 5 && startswith (p, "guile"))
+ else if (command_name_equals (cmd, "guile"))
{
/* Note that we ignore the inline "guile command" form here. */
*command = build_command_line (guile_control, "");
diff --git a/gdb/testsuite/gdb.base/define.exp b/gdb/testsuite/gdb.base/define.exp
index 59203ec..97c47ff 100644
--- a/gdb/testsuite/gdb.base/define.exp
+++ b/gdb/testsuite/gdb.base/define.exp
@@ -147,6 +147,36 @@ gdb_test_multiple "define ifnospace" "define user command: ifnospace" \

gdb_test "ifnospace" ".*hi there.*" "test ifnospace is parsed correctly"

+# Verify that the command parser properly handles command abbreviations.
+with_test_prefix "command abbreviations in define" {
+ set test "define user command: breakmain"
+ gdb_test_multiple "define breakmain" "$test" {
+ -re "Type commands for definition of \"breakmain\".\r\nEnd with a line saying just \"end\".\r\n>$" {
+ pass "$test"
+ set test "send body of breakmain"
+ gdb_test_multiple "break main\ncommand\necho\nend\nend" "$test" {
+ -re "$gdb_prompt $"\
+ {pass "$test"}
+ }
+ }
+ }
+
+ gdb_test "breakmain" ".*Breakpoint .*" "run user command"
+
+ # If GDB fails to interpret properly the abbrev "command", the last "end"
+ # will be missing. Issue it to avoid a desync that would break the other
+ # tests in this file.
+ gdb_test "end" \
+ "This command cannot be used at the top level.*" \
+ "additional end command"
+
+ gdb_test "info break \$bpnum" \
+ "Num Type\[ \]+Disp Enb Address\[ \]+What.*
+\[0-9\]+\[\t \]+breakpoint keep y.* in main at .*
+\[\t \]+echo.*" "info break shows echo command"
+}
+
+
# Verify that the command parser doesn't require a space after an 'while'
# command in a user defined function.
#