Re: [PATCH] guile: Add 'history-push!' procedure

[ludo at gnu dot org (Ludovic CourtÃs)]

Eli Zaretskii <eliz@gnu.org> skribis:

>> From: ludo@gnu.org (Ludovic CourtÃs)
>> Cc: gdb-patches@sourceware.org,  xdje42@gmail.com
>> Date: Wed, 19 Feb 2014 22:43:43 +0100
>> 
>> >> +@deffn {Scheme Procedure} history-push! value
>> >> +Push @var{value}, an instance of @code{<gdb:value>}, to @value{GDBN}'s
>> >> +value history.
>> >
>> > I think we should explain what "push" means in this context.  It is
>> > not self-evident.
>> 
>> Right.  How about s/push/append/?  (In the procedure name as well.)
>
> Fine with me.

Done.

>> >>                 Return its index in the history, or @code{#f} if it is
>> >> +not saved.
>> >
>> > Why would it not be saved?
>> 
>> Good question.  The doc above ârecord_latest_valueâ mentions that it can
>> return -1, but I see no path leading to that.  Can I assume that -1 is
>> never returned?
>
> I don't know, but if that is your reading, I see no reason not to.

OK, I changed it to assume it always returns a positive value.

>> How about simply this:
>> 
>>   Using this function is useful to provide convenient access to values
>>   manipulated by a Guile extension of GDB.
>
> I suggest
>
>   Putting into history values returned by Guile extensions will allow
>   the user convenient access to those values via CLI history
>   facilities.

Perfect.

The version below incorporates those changes.

Thanks,
Ludoâ.

gdb/
2014-02-21  Ludovic CourtÃs  <ludo@gnu.org>

	* guile/scm-value.c (gdbscm_history_append_x): New function.
	(value_functions): Add it.

gdb/testsuite/
2014-02-21  Ludovic CourtÃs  <ludo@gnu.org>

	* gdb.guile/scm-value.exp (test_value_in_inferior): Add
	test for 'history-append!'.

gdb/doc/
2014-02-21  Ludovic CourtÃs  <ludo@gnu.org>

	* gdb/doc/guile.texi (Basic Guile): Document 'history-append!'.
---
 gdb/doc/guile.texi                    |  9 +++++++++
 gdb/guile/scm-value.c                 | 25 +++++++++++++++++++++++++
 gdb/testsuite/gdb.guile/scm-value.exp |  8 ++++++++
 3 files changed, 42 insertions(+)

diff --git a/gdb/doc/guile.texi b/gdb/doc/guile.texi
index ceb98dc..56d817e 100644
--- a/gdb/doc/guile.texi
+++ b/gdb/doc/guile.texi
@@ -278,6 +278,15 @@ history contains the result of evaluating an expression from Guile's
 command line.
 @end deffn
 
+@deffn {Scheme Procedure} history-append! value
+Append @var{value}, an instance of @code{<gdb:value>}, to @value{GDBN}'s
+value history.  Return its index in the history.
+
+Putting into history values returned by Guile extensions will allow
+the user convenient access to those values via CLI history
+facilities.
+@end deffn
+
 @deffn {Scheme Procedure} parse-and-eval expression
 Parse @var{expression} as an expression in the current language,
 evaluate it, and return the result as a @code{<gdb:value>}.
diff --git a/gdb/guile/scm-value.c b/gdb/guile/scm-value.c
index f7f27ce..8ca0762 100644
--- a/gdb/guile/scm-value.c
+++ b/gdb/guile/scm-value.c
@@ -1297,6 +1297,27 @@ gdbscm_history_ref (SCM index)
 
   return vlscm_scm_from_value (res_val);
 }
+
+/* (history-append! <gdb:value>) -> index
+   Append VALUE to GDB's value history.  Return its index in the history.  */
+
+static SCM
+gdbscm_history_append_x (SCM value)
+{
+  int res_index = -1;
+  struct value *v;
+  volatile struct gdb_exception except;
+
+  v = vlscm_scm_to_value (value);
+
+  TRY_CATCH (except, RETURN_MASK_ALL)
+    {
+      res_index = record_latest_value (v);
+    }
+  GDBSCM_HANDLE_GDB_EXCEPTION (except);
+
+  return scm_from_int (res_index);
+}
 
 /* Initialize the Scheme value code.  */
 
@@ -1459,6 +1480,10 @@ Evaluates string in gdb and returns the result as a <gdb:value> object." },
     "\
 Return the specified value from GDB's value history." },
 
+  { "history-append!", 1, 0, 0, gdbscm_history_append_x,
+    "\
+Append the specified value onto GDB's value history." },
+
   END_FUNCTIONS
 };
 
diff --git a/gdb/testsuite/gdb.guile/scm-value.exp b/gdb/testsuite/gdb.guile/scm-value.exp
index 3ebdd58..89f0ff1 100644
--- a/gdb/testsuite/gdb.guile/scm-value.exp
+++ b/gdb/testsuite/gdb.guile/scm-value.exp
@@ -59,6 +59,14 @@ proc test_value_in_inferior {} {
     gdb_test "gu (print (value-field s \"a\"))" \
 	"= 3" "access element inside struct using string name"
 
+    # Append value in the value history.
+    gdb_scm_test_silent_cmd "gu (define i (history-append! (make-value 42)))" \
+	"append 42"
+
+    gdb_test "gu i" "\[0-9\]+"
+    gdb_test "gu (history-ref i)" "#<gdb:value 42>"
+    gdb_test "p \$" "= 42"
+
     # Test dereferencing the argv pointer.
 
     # Just get inferior variable argv the value history, available to guile.
-- 
1.8.4