RE: [Patch] -var-evaluate-expression NAME [FORMAT]

Marc Khouzam
2008-02-05T14:47:51Z

> > I think a solution based on
> > http://sourceware.org/ml/gdb-patches/2008-01/msg00531.html
> > is probably the cleanest. Can I have an educated opinion on
> > this decision?
>
> This also uses value_get_print_value in c_value_of_variable.

Did you mean that this solution "also uses print_value" after Vladimir's
patch? What we would do is use the format parameter that would be
passed all the way to c_value_of_variable; if the specified format is
the same as var->format we call print_value (as done in Vladimir's
patch), but if the format is something different, we call
value_get_print_value (var->value, format). (See below).

> I can't seem to apply your earlier patch as I get spurious characters
> when I save it (= -> =3D, \n -> =20\n, etc) but I wonder if we've made
> things too complicated.

I've redone the patch (slightly cleaner than before). It's at the bottom.

> What happens if you just use value_get_print_value (var->value, var->format)
> directly in mi_cmd_var_evaluate_expression instead of varobj_get_value (var)?

This won't work, because it bypassed all the logic done between the call to
varobj_get_value() and the one to value_get_print_value(); such things as
returning "{...}" for structs and unions, returning "[numChildren]" for arrays;
it would also bypass the checks for var->value == NULL, and value_lazy(), etc.

Marc

==

Indentation is not correct, tests and doc have been removed.
This is just for discussion since I have to wait for my copyright
assignment anyway.
I did test and run regression successfully.

Index: gdb/varobj.h
===================================================================
RCS file: /cvs/src/src/gdb/varobj.h,v
retrieving revision 1.15
diff -u -r1.15 varobj.h
--- gdb/varobj.h 30 Jan 2008 07:17:31 -0000 1.15
+++ gdb/varobj.h 5 Feb 2008 14:37:03 -0000
@@ -109,6 +109,9 @@

extern int varobj_get_attributes (struct varobj *var);

+extern char *varobj_get_formatted_value (struct varobj *var,
+enum varobj_display_formats format);
+
extern char *varobj_get_value (struct varobj *var);

extern int varobj_set_value (struct varobj *var, char *expression);
Index: gdb/varobj.c
===================================================================
RCS file: /cvs/src/src/gdb/varobj.c,v
retrieving revision 1.103
diff -u -r1.103 varobj.c
--- gdb/varobj.c 4 Feb 2008 07:49:04 -0000 1.103
+++ gdb/varobj.c 5 Feb 2008 14:37:03 -0000
@@ -217,7 +217,8 @@

static struct value *value_of_child (struct varobj *parent, int index);

-static char *my_value_of_variable (struct varobj *var);
+static char *my_value_of_variable (struct varobj *var,
+ enum varobj_display_formats format);

static char *value_get_print_value (struct value *value,
enum varobj_display_formats format);
@@ -242,7 +243,8 @@

static struct type *c_type_of_child (struct varobj *parent, int index);

-static char *c_value_of_variable (struct varobj *var);
+static char *c_value_of_variable (struct varobj *var,
+ enum varobj_display_formats format);

/* C++ implementation */

@@ -262,7 +264,8 @@

static struct type *cplus_type_of_child (struct varobj *parent, int index);

-static char *cplus_value_of_variable (struct varobj *var);
+static char *cplus_value_of_variable (struct varobj *var,
+ enum varobj_display_formats format);

/* Java implementation */

@@ -280,7 +283,8 @@

static struct type *java_type_of_child (struct varobj *parent, int index);

-static char *java_value_of_variable (struct varobj *var);
+static char *java_value_of_variable (struct varobj *var,
+ enum varobj_display_formats format);

/* The language specific vector */

@@ -313,7 +317,8 @@
struct type *(*type_of_child) (struct varobj * parent, int index);

/* The current value of VAR. */
- char *(*value_of_variable) (struct varobj * var);
+ char *(*value_of_variable) (struct varobj * var,
+ enum varobj_display_formats format);
};

/* Array of known source language routines. */
@@ -833,9 +838,16 @@
}

char *
+varobj_get_formatted_value (struct varobj *var,
+ enum varobj_display_formats format)
+{
+ return my_value_of_variable (var, format);
+}
+
+char *
varobj_get_value (struct varobj *var)
{
- return my_value_of_variable (var);
+ return my_value_of_variable (var, var->format);
}

/* Set the value of an object variable (if it is editable) to the
@@ -1770,10 +1782,11 @@

/* GDB already has a command called "value_of_variable". Sigh. */
static char *
-my_value_of_variable (struct varobj *var)
+my_value_of_variable (struct varobj *var,
+ enum varobj_display_formats format)
{
if (var->root->is_valid)
- return (*var->root->lang->value_of_variable) (var);
+ return (*var->root->lang->value_of_variable) (var, format);
else
return NULL;
}
@@ -2207,7 +2220,8 @@
}

static char *
-c_value_of_variable (struct varobj *var)
+c_value_of_variable (struct varobj *var,
+ enum varobj_display_formats format)
{
/* BOGUS: if val_print sees a struct/class, or a reference to one,
it will print out its children instead of "{...}". So we need to
@@ -2252,7 +2266,13 @@

gdb_assert (varobj_value_is_changeable_p (var));
gdb_assert (!value_lazy (var->value));
- return xstrdup (var->print_value);
+
+ /* If the specified format is the current one,
+ we can reuse print_value */
+ if (format == var->format)
+ return xstrdup (var->print_value);
+ else
+ return value_get_print_value (var->value, format);
}
}
}
@@ -2578,7 +2598,8 @@
}

static char *
-cplus_value_of_variable (struct varobj *var)
+cplus_value_of_variable (struct varobj *var,
+ enum varobj_display_formats format)
{

/* If we have one of our special types, don't print out
@@ -2586,7 +2607,7 @@
if (CPLUS_FAKE_CHILD (var))
return xstrdup ("");

- return c_value_of_variable (var);
+ return c_value_of_variable (var, format);
}

/* Java */
@@ -2661,9 +2682,10 @@
}

static char *
-java_value_of_variable (struct varobj *var)
+java_value_of_variable (struct varobj *var,
+ enum varobj_display_formats format)
{
- return cplus_value_of_variable (var);
+ return cplus_value_of_variable (var, format);
}

extern void _initialize_varobj (void);
Index: gdb/Makefile.in
===================================================================
RCS file: /cvs/src/src/gdb/Makefile.in,v
retrieving revision 1.978
diff -u -r1.978 Makefile.in
--- gdb/Makefile.in 30 Jan 2008 07:17:31 -0000 1.978
+++ gdb/Makefile.in 5 Feb 2008 14:37:03 -0000
@@ -3208,7 +3208,7 @@
$(mi_getopt_h) $(remote_h)
$(CC) -c $(INTERNAL_CFLAGS) $(srcdir)/mi/mi-cmd-target.c
mi-cmd-var.o: $(srcdir)/mi/mi-cmd-var.c $(defs_h) $(mi_cmds_h) $(ui_out_h) \
- $(mi_out_h) $(varobj_h) $(value_h) $(gdb_string_h)
+ $(mi_out_h) $(varobj_h) $(value_h) $(gdb_string_h) $(mi_getopt_h)
$(CC) -c $(INTERNAL_CFLAGS) $(srcdir)/mi/mi-cmd-var.c
mi-console.o: $(srcdir)/mi/mi-console.c $(defs_h) $(mi_console_h) \
$(gdb_string_h)
Index: gdb/mi/mi-cmd-var.c
===================================================================
RCS file: /cvs/src/src/gdb/mi/mi-cmd-var.c,v
retrieving revision 1.45
diff -u -r1.45 mi-cmd-var.c
--- gdb/mi/mi-cmd-var.c 30 Jan 2008 07:17:31 -0000 1.45
+++ gdb/mi/mi-cmd-var.c 5 Feb 2008 14:37:09 -0000
@@ -28,6 +28,7 @@
#include "value.h"
#include <ctype.h>
#include "gdb_string.h"
+#include "mi-getopt.h"

const char mi_no_values[] = "--no-values";
const char mi_simple_values[] = "--simple-values";
@@ -190,11 +191,33 @@
return MI_CMD_DONE;
}

+/* Parse a string argument into a format value. */
+
+static enum varobj_display_formats
+mi_parse_format (const char *arg)
+{
+ int len;
+
+ len = strlen (arg);
+
+ if (strncmp (arg, "natural", len) == 0)
+ return FORMAT_NATURAL;
+ else if (strncmp (arg, "binary", len) == 0)
+ return FORMAT_BINARY;
+ else if (strncmp (arg, "decimal", len) == 0)
+ return FORMAT_DECIMAL;
+ else if (strncmp (arg, "hexadecimal", len) == 0)
+ return FORMAT_HEXADECIMAL;
+ else if (strncmp (arg, "octal", len) == 0)
+ return FORMAT_OCTAL;
+ else
+ error (_("Unknown display format: must be: \"natural\", \"binary\", \"decimal\", \"hexadecimal\", or \"octal\""));
+}
+
enum mi_cmd_result
mi_cmd_var_set_format (char *command, char **argv, int argc)
{
enum varobj_display_formats format;
- int len;
struct varobj *var;
char *formspec;

@@ -211,21 +234,8 @@
if (formspec == NULL)
error (_("mi_cmd_var_set_format: Must specify the format as: \"natural\", \"binary\", \"decimal\", \"hexadecimal\", or \"octal\""));

- len = strlen (formspec);
-
- if (strncmp (formspec, "natural", len) == 0)
- format = FORMAT_NATURAL;
- else if (strncmp (formspec, "binary", len) == 0)
- format = FORMAT_BINARY;
- else if (strncmp (formspec, "decimal", len) == 0)
- format = FORMAT_DECIMAL;
- else if (strncmp (formspec, "hexadecimal", len) == 0)
- format = FORMAT_HEXADECIMAL;
- else if (strncmp (formspec, "octal", len) == 0)
- format = FORMAT_OCTAL;
- else
- error (_("mi_cmd_var_set_format: Unknown display format: must be: \"natural\", \"binary\", \"decimal\", \"hexadecimal\", or \"octal\""));
-
+ format = mi_parse_format (formspec);
+
/* Set the format of VAR to given format */
varobj_set_display_format (var, format);

@@ -487,16 +497,58 @@
mi_cmd_var_evaluate_expression (char *command, char **argv, int argc)
{
struct varobj *var;
+ enum varobj_display_formats format;
+ int formatFound;
+ int optind;
+ char *optarg;
+
+ enum opt
+ {
+ OP_FORMAT
+ };
+ static struct mi_opt opts[] =
+ {
+ {"f", OP_FORMAT, 1},
+ { 0, 0, 0 }
+ };
+
+ /* Parse arguments */
+ format = FORMAT_NATURAL;
+ formatFound = 0;
+ optind = 0;
+ while (1)
+ {
+ int opt = mi_getopt ("mi_cmd_var_evaluate_expression", argc, argv, opts, &optind, &optarg);
+ if (opt < 0)
+ break;
+ switch ((enum opt) opt)
+ {
+ case OP_FORMAT:
+ if (formatFound)
+ error (_("mi_cmd_var_evaluate_expression: cannot specify format more than once"));

- if (argc != 1)
- error (_("mi_cmd_var_evaluate_expression: Usage: NAME."));
+ format = mi_parse_format (optarg);
+ formatFound = 1;
+ break;
+ }
+ }
+
+ if (optind >= argc)
+ error (_("mi_cmd_var_evaluate_expression: Usage: [-f FORMAT] NAME"));

+ if (optind < argc - 1)
+ error (_("mi_cmd_var_evaluate_expression: Garbage at end of command"));
+
/* Get varobj handle, if a valid var obj name was specified */
- var = varobj_get_handle (argv[0]);
+ var = varobj_get_handle (argv[optind]);
if (var == NULL)
error (_("mi_cmd_var_evaluate_expression: Variable object not found"));

- ui_out_field_string (uiout, "value", varobj_get_value (var));
+ if (formatFound)
+ ui_out_field_string (uiout, "value", varobj_get_formatted_value (var, format));
+ else
+ ui_out_field_string (uiout, "value", varobj_get_value (var));
+
return MI_CMD_DONE;
}

@@ -558,9 +610,9 @@
nv = varobj_list (&rootlist);
cleanup = make_cleanup (xfree, rootlist);
if (mi_version (uiout) <= 1)
- make_cleanup_ui_out_tuple_begin_end (uiout, "changelist");
+ make_cleanup_ui_out_tuple_begin_end (uiout, "changelist");
else
- make_cleanup_ui_out_list_begin_end (uiout, "changelist");
+ make_cleanup_ui_out_list_begin_end (uiout, "changelist");
if (nv <= 0)
{
do_cleanups (cleanup);
@@ -582,9 +634,9 @@
error (_("mi_cmd_var_update: Variable object not found"));

if (mi_version (uiout) <= 1)
- cleanup = make_cleanup_ui_out_tuple_begin_end (uiout, "changelist");
+ cleanup = make_cleanup_ui_out_tuple_begin_end (uiout, "changelist");
else
- cleanup = make_cleanup_ui_out_list_begin_end (uiout, "changelist");
+ cleanup = make_cleanup_ui_out_list_begin_end (uiout, "changelist");
varobj_update_one (var, print_values, 1 /* explicit */);
do_cleanups (cleanup);
}
@@ -613,26 +665,26 @@
else if (nc < 0)
{
if (mi_version (uiout) > 1)
- cleanup = make_cleanup_ui_out_tuple_begin_end (uiout, NULL);
+ cleanup = make_cleanup_ui_out_tuple_begin_end (uiout, NULL);
ui_out_field_string (uiout, "name", varobj_get_objname(var));

switch (nc)
{
- case NOT_IN_SCOPE:
- ui_out_field_string (uiout, "in_scope", "false");
+ case NOT_IN_SCOPE:
+ ui_out_field_string (uiout, "in_scope", "false");
+ break;
+ case INVALID:
+ ui_out_field_string (uiout, "in_scope", "invalid");
break;
- case INVALID:
- ui_out_field_string (uiout, "in_scope", "invalid");
- break;
- case TYPE_CHANGED:
+ case TYPE_CHANGED:
ui_out_field_string (uiout, "in_scope", "true");
- ui_out_field_string (uiout, "new_type", varobj_get_type(var));
- ui_out_field_int (uiout, "new_num_children",
+ ui_out_field_string (uiout, "new_type", varobj_get_type(var));
+ ui_out_field_int (uiout, "new_num_children",
varobj_get_num_children(var));
break;
}
if (mi_version (uiout) > 1)
- do_cleanups (cleanup);
+ do_cleanups (cleanup);
}
else
{