[PATCH] Print nonexisting/optimized out static fields gracefully.

Pedro Alves
2013-10-10T18:25:15Z

With:

struct static_struct { static int aaa; };
struct static_struct sss;
int main () { return 0; }

We get:

(gdb) p sss
$1 = {static aaa = <optimized out>}
(gdb) p sss.aaa
field aaa is nonexistent or has been optimized out

Note that the "field aaa ..." message is an error being thrown.

GDB is graceful everywhere else when printing optimized out values.
IOW it usually prints an <optimized out> value and puts that in the
value history. I see no reason for here to be different, more so that
when the print the whole "containing" object (well, it's a static
field, so it's not really a container), we already print <optimized
out>.

After the patch:

(gdb) p sss
$1 = {static aaa = <optimized out>}
(gdb) p sss.aaa
field aaa is nonexistent or has been optimized out
(gdb) p sss.aaa
$2 = <optimized out>

The value_entirely_optimized_out checks are there to preserve
behavior. Without those, if the static field is a struct/union, GDB
would go and print its fields one by one (and print <optimized out>
for each).

Tested on x86_64 Fedora 17.

gdb/
2013-10-10 Pedro Alves <palves@redhat.com>

* cp-valprint.c (cp_print_value_fields): No longer handle a NULL
static field value.
(cp_print_static_field): If the value is entirely optimized out,
print <optimized out> here.
* jv-valprint.c (java_print_value_fields): No longer handle a NULL
static field value.
* p-valprint.c (pascal_object_print_static_field): If the value is
entirely optimized out, print <optimized out> here.
* valops.c (do_search_struct_field)
(value_struct_elt_for_reference): No longer handle a NULL static
field value.
* value.c (value_static_field): Return an optimized out value
instead of NULL.

gdb/testsuite/
2013-10-10 Pedro Alves <palves@redhat.com>

* gdb.cp/m-static.exp: Adjust expected output of printing a
nonexistent or optimized out static field. Also test printing the
the "container" object.
---
gdb/cp-valprint.c | 17 ++++++++++-------
gdb/jv-valprint.c | 22 ++++++++--------------
gdb/p-valprint.c | 6 ++++++
gdb/testsuite/gdb.cp/m-static.exp | 5 ++++-
gdb/valops.c | 11 +----------
gdb/value.c | 5 ++---
6 files changed, 31 insertions(+), 35 deletions(-)

diff --git a/gdb/cp-valprint.c b/gdb/cp-valprint.c
index 1d7147c..4b625d1 100644
--- a/gdb/cp-valprint.c
+++ b/gdb/cp-valprint.c
@@ -333,12 +333,9 @@ cp_print_value_fields (struct type *type, struct type *real_type,
fprintf_filtered (stream,
_("<error reading variable: %s>"),
ex.message);
- else if (v == NULL)
- val_print_optimized_out (NULL, stream);
- else
- cp_print_static_field (TYPE_FIELD_TYPE (type, i),
- v, stream, recurse + 1,
- options);
+ cp_print_static_field (TYPE_FIELD_TYPE (type, i),
+ v, stream, recurse + 1,
+ options);
}
else if (i == vptr_fieldno && type == vptr_basetype)
{
@@ -640,7 +637,13 @@ cp_print_static_field (struct type *type,
const struct value_print_options *options)
{
struct value_print_options opts;
-
+
+ if (value_entirely_optimized_out (val))
+ {
+ val_print_optimized_out (val, stream);
+ return;
+ }
+
if (TYPE_CODE (type) == TYPE_CODE_STRUCT)
{
CORE_ADDR *first_dont_print;
diff --git a/gdb/jv-valprint.c b/gdb/jv-valprint.c
index cb89a85..2c60cc0 100644
--- a/gdb/jv-valprint.c
+++ b/gdb/jv-valprint.c
@@ -417,22 +417,16 @@ java_print_value_fields (struct type *type, const gdb_byte *valaddr,
}
else if (field_is_static (&TYPE_FIELD (type, i)))
{
+ struct value_print_options opts;
struct value *v = value_static_field (type, i);
+ struct type *t = check_typedef (value_type (v));

- if (v == NULL)
- val_print_optimized_out (NULL, stream);
- else
- {
- struct value_print_options opts;
- struct type *t = check_typedef (value_type (v));
-
- if (TYPE_CODE (t) == TYPE_CODE_STRUCT)
- v = value_addr (v);
- opts = *options;
- opts.deref_ref = 0;
- common_val_print (v, stream, recurse + 1,
- &opts, current_language);
- }
+ if (TYPE_CODE (t) == TYPE_CODE_STRUCT)
+ v = value_addr (v);
+ opts = *options;
+ opts.deref_ref = 0;
+ common_val_print (v, stream, recurse + 1,
+ &opts, current_language);
}
else if (TYPE_FIELD_TYPE (type, i) == NULL)
fputs_filtered ("<unknown type>", stream);
diff --git a/gdb/p-valprint.c b/gdb/p-valprint.c
index e6d4b91..7854bc0 100644
--- a/gdb/p-valprint.c
+++ b/gdb/p-valprint.c
@@ -844,6 +844,12 @@ pascal_object_print_static_field (struct value *val,
struct type *type = value_type (val);
struct value_print_options opts;

+ if (value_entirely_optimized_out (val))
+ {
+ val_print_optimized_out (val, stream);
+ return;
+ }
+
if (TYPE_CODE (type) == TYPE_CODE_STRUCT)
{
CORE_ADDR *first_dont_print, addr;
diff --git a/gdb/testsuite/gdb.cp/m-static.exp b/gdb/testsuite/gdb.cp/m-static.exp
index 9b0e642..a5d388c 100644
--- a/gdb/testsuite/gdb.cp/m-static.exp
+++ b/gdb/testsuite/gdb.cp/m-static.exp
@@ -169,7 +169,10 @@ if {[test_compiler_info {gcc-[0-3]-*}]
# and DW_AT_MIPS_linkage_name = _ZN9gnu_obj_47nowhereE .
setup_xfail *-*-*
}
-gdb_test "print test4.nowhere" "field nowhere is nonexistent or has been optimized out" "static const int initialized nowhere"
+gdb_test "print test4.nowhere" "<optimized out>" "static const int initialized nowhere (print field)"
+
+# Same, but print the whole struct.
+gdb_test "print test4" "static nowhere = <optimized out>.*" "static const int initialized nowhere (whole struct)"

# static const initialized in the class definition, PR gdb/11702.
if { $non_dwarf } { setup_xfail *-*-* }
diff --git a/gdb/valops.c b/gdb/valops.c
index 15fd7c3..8bff686 100644
--- a/gdb/valops.c
+++ b/gdb/valops.c
@@ -1853,13 +1853,7 @@ do_search_struct_field (const char *name, struct value *arg1, int offset,
struct value *v;

if (field_is_static (&TYPE_FIELD (type, i)))
- {
- v = value_static_field (type, i);
- if (v == 0)
- error (_("field %s is nonexistent or "
- "has been optimized out"),
- name);
- }
+ v = value_static_field (type, i);
else
v = value_primitive_field (arg1, offset, i, type);
*result_ptr = v;
@@ -3123,9 +3117,6 @@ value_struct_elt_for_reference (struct type *domain, int offset,
if (field_is_static (&TYPE_FIELD (t, i)))
{
v = value_static_field (t, i);
- if (v == NULL)
- error (_("static field %s has been optimized out"),
- name);
if (want_address)
v = value_addr (v);
return v;
diff --git a/gdb/value.c b/gdb/value.c
index d96d285..1f562f5 100644
--- a/gdb/value.c
+++ b/gdb/value.c
@@ -2590,8 +2590,7 @@ unpack_pointer (struct type *type, const gdb_byte *valaddr)

\f
/* Get the value of the FIELDNO'th field (which must be static) of
- TYPE. Return NULL if the field doesn't exist or has been
- optimized out. */
+ TYPE. */

struct value *
value_static_field (struct type *type, int fieldno)
@@ -2618,7 +2617,7 @@ value_static_field (struct type *type, int fieldno)
NULL, NULL);

if (!msym)
- return NULL;
+ return allocate_optimized_out_value (type);
else
{
retval = value_at_lazy (TYPE_FIELD_TYPE (type, fieldno),
--
1.7.11.7