Re: RFA: shrink main_type

Ken Werner
2010-09-15T12:42:04Z

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On Tuesday, August 19, 2008 07:55:37 pm Tom Tromey wrote:
> + /* Flags about this type. These fields appear at this location
> + because they packs nicely here. See the TYPE_* macros for
> + documentation about these fields. */
> +
> + unsigned int flag_unsigned : 1;
> + unsigned int flag_nosign : 1;
> + unsigned int flag_stub : 1;
> + unsigned int flag_target_stub : 1;
> + unsigned int flag_static : 1;
> + unsigned int flag_prototyped : 1;
> + unsigned int flag_incomplete : 1;
> + unsigned int flag_varargs : 1;
> + unsigned int flag_vector : 1;
> + unsigned int flag_stub_supported : 1;
> + unsigned int flag_nottext : 1;
> + unsigned int flag_fixed_instance : 1;

Hi Tom,

This is quite an old change but while debugging gdb I noticed that vector
types do have a strange bit set into their instance_flags and this seems to go
back to this patch.
The snippet above introduces the flag_nottext as a bitfield member of the type
struct while gdbtypes.c:make_vector_type still sets that bit into the
instance_flags.

The nottext flag is set for the element types of vectors
(gdbtypes.c:make_vector_type) and for the builtin_int8/builtin_int8 types. The
flag is read from the c-valprint.c:c_textual_element_type function that
determines whether arrays of chars should be printed as strings or not. So, I
guess that prior to this patch char vectors were printed just like integer
vectors - plain data. One approach to restore that functionality would be to
move the nottext flag into to the instance_flags of the type. Attached is an
untested patch of what I have in mind. Comments are welcome.

This also renders my previous attempt to fix the printing of character vectors
(http://sourceware.org/ml/gdb-patches/2010-06/msg00573.html) obsolete.

Regards
Ken Werner

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Index: gdb/c-valprint.c
===================================================================
RCS file: /cvs/src/src/gdb/c-valprint.c,v
retrieving revision 1.72
diff -p -u -r1.72 c-valprint.c
--- gdb/c-valprint.c 14 Jul 2010 14:13:54 -0000 1.72
+++ gdb/c-valprint.c 15 Sep 2010 12:22:49 -0000
@@ -180,8 +180,7 @@ c_val_print (struct type *type, const gd

/* Print arrays of textual chars with a string syntax, as
long as the entire array is valid. */
- if (!TYPE_VECTOR (type)
- && c_textual_element_type (unresolved_elttype, options->format)
+ if (c_textual_element_type (unresolved_elttype, options->format)
&& value_bits_valid (original_value,
TARGET_CHAR_BIT * embedded_offset,
TARGET_CHAR_BIT * TYPE_LENGTH (type)))
Index: gdb/gdbtypes.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbtypes.c,v
retrieving revision 1.199
diff -p -u -r1.199 gdbtypes.c
--- gdb/gdbtypes.c 8 Sep 2010 17:17:42 -0000 1.199
+++ gdb/gdbtypes.c 15 Sep 2010 12:22:49 -0000
@@ -942,7 +942,7 @@ make_vector_type (struct type *array_typ
elt_type = TYPE_TARGET_TYPE (inner_array);
if (TYPE_CODE (elt_type) == TYPE_CODE_INT)
{
- flags = TYPE_INSTANCE_FLAGS (elt_type) | TYPE_FLAG_NOTTEXT;
+ flags = TYPE_INSTANCE_FLAGS (elt_type) | TYPE_INSTANCE_FLAG_NOTTEXT;
elt_type = make_qualified_type (elt_type, flags, NULL);
TYPE_TARGET_TYPE (inner_array) = elt_type;
}
@@ -1801,8 +1801,6 @@ init_type (enum type_code code, int leng
TYPE_VECTOR (type) = 1;
if (flags & TYPE_FLAG_STUB_SUPPORTED)
TYPE_STUB_SUPPORTED (type) = 1;
- if (flags & TYPE_FLAG_NOTTEXT)
- TYPE_NOTTEXT (type) = 1;
if (flags & TYPE_FLAG_FIXED_INSTANCE)
TYPE_FIXED_INSTANCE (type) = 1;

@@ -3490,8 +3488,10 @@ gdbtypes_post_init (struct gdbarch *gdba
= arch_integer_type (gdbarch, 128, 0, "int128_t");
builtin_type->builtin_uint128
= arch_integer_type (gdbarch, 128, 1, "uint128_t");
- TYPE_NOTTEXT (builtin_type->builtin_int8) = 1;
- TYPE_NOTTEXT (builtin_type->builtin_uint8) = 1;
+ TYPE_INSTANCE_FLAGS (builtin_type->builtin_int8) |=
+ TYPE_INSTANCE_FLAG_NOTTEXT;
+ TYPE_INSTANCE_FLAGS (builtin_type->builtin_uint8) |=
+ TYPE_INSTANCE_FLAG_NOTTEXT;

/* Wide character types. */
builtin_type->builtin_char16
Index: gdb/gdbtypes.h
===================================================================
RCS file: /cvs/src/src/gdb/gdbtypes.h,v
retrieving revision 1.134
diff -p -u -r1.134 gdbtypes.h
--- gdb/gdbtypes.h 28 Jul 2010 16:23:58 -0000 1.134
+++ gdb/gdbtypes.h 15 Sep 2010 12:22:49 -0000
@@ -159,18 +159,17 @@ enum type_code

enum type_flag_value
{
- TYPE_FLAG_UNSIGNED = (1 << 6),
- TYPE_FLAG_NOSIGN = (1 << 7),
- TYPE_FLAG_STUB = (1 << 8),
- TYPE_FLAG_TARGET_STUB = (1 << 9),
- TYPE_FLAG_STATIC = (1 << 10),
- TYPE_FLAG_PROTOTYPED = (1 << 11),
- TYPE_FLAG_INCOMPLETE = (1 << 12),
- TYPE_FLAG_VARARGS = (1 << 13),
- TYPE_FLAG_VECTOR = (1 << 14),
- TYPE_FLAG_FIXED_INSTANCE = (1 << 15),
- TYPE_FLAG_STUB_SUPPORTED = (1 << 16),
- TYPE_FLAG_NOTTEXT = (1 << 17),
+ TYPE_FLAG_UNSIGNED = (1 << 7),
+ TYPE_FLAG_NOSIGN = (1 << 8),
+ TYPE_FLAG_STUB = (1 << 9),
+ TYPE_FLAG_TARGET_STUB = (1 << 10),
+ TYPE_FLAG_STATIC = (1 << 11),
+ TYPE_FLAG_PROTOTYPED = (1 << 12),
+ TYPE_FLAG_INCOMPLETE = (1 << 13),
+ TYPE_FLAG_VARARGS = (1 << 14),
+ TYPE_FLAG_VECTOR = (1 << 15),
+ TYPE_FLAG_FIXED_INSTANCE = (1 << 16),
+ TYPE_FLAG_STUB_SUPPORTED = (1 << 17),

/* Used for error-checking. */
TYPE_FLAG_MIN = TYPE_FLAG_UNSIGNED
@@ -186,7 +185,8 @@ enum type_instance_flag_value
TYPE_INSTANCE_FLAG_CODE_SPACE = (1 << 2),
TYPE_INSTANCE_FLAG_DATA_SPACE = (1 << 3),
TYPE_INSTANCE_FLAG_ADDRESS_CLASS_1 = (1 << 4),
- TYPE_INSTANCE_FLAG_ADDRESS_CLASS_2 = (1 << 5)
+ TYPE_INSTANCE_FLAG_ADDRESS_CLASS_2 = (1 << 5),
+ TYPE_INSTANCE_FLAG_NOTTEXT = (1 << 6),
};

/* Unsigned integer type. If this is not set for a TYPE_CODE_INT, the
@@ -269,7 +269,7 @@ enum type_instance_flag_value
/* Not textual. By default, GDB treats all single byte integers as
characters (or elements of strings) unless this flag is set. */

-#define TYPE_NOTTEXT(t) (TYPE_MAIN_TYPE (t)->flag_nottext)
+#define TYPE_NOTTEXT(t) (TYPE_INSTANCE_FLAGS (t) & TYPE_INSTANCE_FLAG_NOTTEXT)

/* Type owner. If TYPE_OBJFILE_OWNED is true, the type is owned by
the objfile retrieved as TYPE_OBJFILE. Otherweise, the type is
@@ -388,7 +388,6 @@ struct main_type
unsigned int flag_varargs : 1;
unsigned int flag_vector : 1;
unsigned int flag_stub_supported : 1;
- unsigned int flag_nottext : 1;
unsigned int flag_fixed_instance : 1;
unsigned int flag_objfile_owned : 1;
/* True if this type was declared with "class" rather than