1 /* Language independent support for printing types for GDB, the GNU debugger.
3 Copyright (C) 1986-2020 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
21 #include "gdb_obstack.h"
22 #include "bfd.h" /* Binary File Description */
25 #include "expression.h"
33 #include "typeprint.h"
36 #include "cli/cli-utils.h"
37 #include "extension.h"
38 #include "completer.h"
39 #include "cli/cli-style.h"
41 const struct type_print_options type_print_raw_options
=
44 1, /* print_methods */
45 1, /* print_typedefs */
46 0, /* print_offsets */
47 0, /* print_nested_type_limit */
48 NULL
, /* local_typedefs */
49 NULL
, /* global_table */
50 NULL
/* global_printers */
53 /* The default flags for 'ptype' and 'whatis'. */
55 static struct type_print_options default_ptype_flags
=
58 1, /* print_methods */
59 1, /* print_typedefs */
60 0, /* print_offsets */
61 0, /* print_nested_type_limit */
62 NULL
, /* local_typedefs */
63 NULL
, /* global_table */
64 NULL
/* global_printers */
69 /* See typeprint.h. */
71 const int print_offset_data::indentation
= 23;
74 /* See typeprint.h. */
77 print_offset_data::maybe_print_hole (struct ui_file
*stream
,
81 /* We check for END_BITPOS > 0 because there is a specific
82 scenario when END_BITPOS can be zero and BITPOS can be >
83 0: when we are dealing with a struct/class with a virtual method.
84 Because of the vtable, the first field of the struct/class will
85 have an offset of sizeof (void *) (the size of the vtable). If
86 we do not check for END_BITPOS > 0 here, GDB will report
87 a hole before the first field, which is not accurate. */
88 if (end_bitpos
> 0 && end_bitpos
< bitpos
)
90 /* If END_BITPOS is smaller than the current type's
91 bitpos, it means there's a hole in the struct, so we report
93 unsigned int hole
= bitpos
- end_bitpos
;
94 unsigned int hole_byte
= hole
/ TARGET_CHAR_BIT
;
95 unsigned int hole_bit
= hole
% TARGET_CHAR_BIT
;
98 fprintf_filtered (stream
, "/* XXX %2u-bit %s */\n", hole_bit
,
102 fprintf_filtered (stream
, "/* XXX %2u-byte %s */\n", hole_byte
,
107 /* See typeprint.h. */
110 print_offset_data::update (struct type
*type
, unsigned int field_idx
,
111 struct ui_file
*stream
)
113 if (field_is_static (&type
->field (field_idx
)))
115 print_spaces_filtered (indentation
, stream
);
119 struct type
*ftype
= check_typedef (type
->field (field_idx
).type ());
120 if (type
->code () == TYPE_CODE_UNION
)
122 /* Since union fields don't have the concept of offsets, we just
123 print their sizes. */
124 fprintf_filtered (stream
, "/* %4s */",
125 pulongest (TYPE_LENGTH (ftype
)));
129 unsigned int bitpos
= TYPE_FIELD_BITPOS (type
, field_idx
);
130 unsigned int fieldsize_byte
= TYPE_LENGTH (ftype
);
131 unsigned int fieldsize_bit
= fieldsize_byte
* TARGET_CHAR_BIT
;
133 maybe_print_hole (stream
, bitpos
, "hole");
135 if (TYPE_FIELD_PACKED (type
, field_idx
)
136 || offset_bitpos
% TARGET_CHAR_BIT
!= 0)
138 /* We're dealing with a bitfield. Print the bit offset. */
139 fieldsize_bit
= TYPE_FIELD_BITSIZE (type
, field_idx
);
141 unsigned real_bitpos
= bitpos
+ offset_bitpos
;
143 fprintf_filtered (stream
, "/* %4u:%2u", real_bitpos
/ TARGET_CHAR_BIT
,
144 real_bitpos
% TARGET_CHAR_BIT
);
148 /* The position of the field, relative to the beginning of the
150 fprintf_filtered (stream
, "/* %4u",
151 (bitpos
+ offset_bitpos
) / TARGET_CHAR_BIT
);
153 fprintf_filtered (stream
, " ");
156 fprintf_filtered (stream
, " | %4u */", fieldsize_byte
);
158 end_bitpos
= bitpos
+ fieldsize_bit
;
161 /* See typeprint.h. */
164 print_offset_data::finish (struct type
*type
, int level
,
165 struct ui_file
*stream
)
167 unsigned int bitpos
= TYPE_LENGTH (type
) * TARGET_CHAR_BIT
;
168 maybe_print_hole (stream
, bitpos
, "padding");
170 fputs_filtered ("\n", stream
);
171 print_spaces_filtered (level
+ 4 + print_offset_data::indentation
, stream
);
172 fprintf_filtered (stream
, "/* total size (bytes): %4s */\n",
173 pulongest (TYPE_LENGTH (type
)));
178 /* A hash function for a typedef_field. */
181 hash_typedef_field (const void *p
)
183 const struct decl_field
*tf
= (const struct decl_field
*) p
;
184 struct type
*t
= check_typedef (tf
->type
);
186 return htab_hash_string (TYPE_SAFE_NAME (t
));
189 /* An equality function for a typedef field. */
192 eq_typedef_field (const void *a
, const void *b
)
194 const struct decl_field
*tfa
= (const struct decl_field
*) a
;
195 const struct decl_field
*tfb
= (const struct decl_field
*) b
;
197 return types_equal (tfa
->type
, tfb
->type
);
200 /* See typeprint.h. */
203 typedef_hash_table::recursively_update (struct type
*t
)
207 for (i
= 0; i
< TYPE_TYPEDEF_FIELD_COUNT (t
); ++i
)
209 struct decl_field
*tdef
= &TYPE_TYPEDEF_FIELD (t
, i
);
212 slot
= htab_find_slot (m_table
, tdef
, INSERT
);
213 /* Only add a given typedef name once. Really this shouldn't
214 happen; but it is safe enough to do the updates breadth-first
215 and thus use the most specific typedef. */
220 /* Recurse into superclasses. */
221 for (i
= 0; i
< TYPE_N_BASECLASSES (t
); ++i
)
222 recursively_update (TYPE_BASECLASS (t
, i
));
225 /* See typeprint.h. */
228 typedef_hash_table::add_template_parameters (struct type
*t
)
232 for (i
= 0; i
< TYPE_N_TEMPLATE_ARGUMENTS (t
); ++i
)
234 struct decl_field
*tf
;
237 /* We only want type-valued template parameters in the hash. */
238 if (SYMBOL_CLASS (TYPE_TEMPLATE_ARGUMENT (t
, i
)) != LOC_TYPEDEF
)
241 tf
= XOBNEW (&m_storage
, struct decl_field
);
242 tf
->name
= TYPE_TEMPLATE_ARGUMENT (t
, i
)->linkage_name ();
243 tf
->type
= SYMBOL_TYPE (TYPE_TEMPLATE_ARGUMENT (t
, i
));
245 slot
= htab_find_slot (m_table
, tf
, INSERT
);
251 /* See typeprint.h. */
253 typedef_hash_table::typedef_hash_table ()
255 m_table
= htab_create_alloc (10, hash_typedef_field
, eq_typedef_field
,
256 NULL
, xcalloc
, xfree
);
259 /* Free a typedef field table. */
261 typedef_hash_table::~typedef_hash_table ()
263 htab_delete (m_table
);
266 /* Helper function for typedef_hash_table::copy. */
269 copy_typedef_hash_element (void **slot
, void *nt
)
271 htab_t new_table
= (htab_t
) nt
;
274 new_slot
= htab_find_slot (new_table
, *slot
, INSERT
);
275 if (*new_slot
== NULL
)
281 /* See typeprint.h. */
283 typedef_hash_table::typedef_hash_table (const typedef_hash_table
&table
)
285 m_table
= htab_create_alloc (10, hash_typedef_field
, eq_typedef_field
,
286 NULL
, xcalloc
, xfree
);
287 htab_traverse_noresize (table
.m_table
, copy_typedef_hash_element
,
291 /* Look up the type T in the global typedef hash. If it is found,
292 return the typedef name. If it is not found, apply the
293 type-printers, if any, given by start_script_type_printers and return the
294 result. A NULL return means that the name was not found. */
297 typedef_hash_table::find_global_typedef (const struct type_print_options
*flags
,
302 struct decl_field tf
, *new_tf
;
304 if (flags
->global_typedefs
== NULL
)
310 slot
= htab_find_slot (flags
->global_typedefs
->m_table
, &tf
, INSERT
);
313 new_tf
= (struct decl_field
*) *slot
;
317 /* Put an entry into the hash table now, in case
318 apply_ext_lang_type_printers recurses. */
319 new_tf
= XOBNEW (&flags
->global_typedefs
->m_storage
, struct decl_field
);
325 applied
= apply_ext_lang_type_printers (flags
->global_printers
, t
);
329 new_tf
->name
= obstack_strdup (&flags
->global_typedefs
->m_storage
,
337 /* See typeprint.h. */
340 typedef_hash_table::find_typedef (const struct type_print_options
*flags
,
343 if (flags
->local_typedefs
!= NULL
)
345 struct decl_field tf
, *found
;
349 found
= (struct decl_field
*) htab_find (flags
->local_typedefs
->m_table
,
356 return find_global_typedef (flags
, t
);
361 /* Print a description of a type in the format of a
362 typedef for the current language.
363 NEW is the new name for a type TYPE. */
366 typedef_print (struct type
*type
, struct symbol
*newobj
, struct ui_file
*stream
)
368 LA_PRINT_TYPEDEF (type
, newobj
, stream
);
371 /* Print a description of a type TYPE in the form of a declaration of a
372 variable named VARSTRING. (VARSTRING is demangled if necessary.)
373 Output goes to STREAM (via stdio).
374 If SHOW is positive, we show the contents of the outermost level
375 of structure even if there is a type name that could be used instead.
376 If SHOW is negative, we never show the details of elements' types. */
379 type_print (struct type
*type
, const char *varstring
, struct ui_file
*stream
,
382 LA_PRINT_TYPE (type
, varstring
, stream
, show
, 0, &default_ptype_flags
);
385 /* Print TYPE to a string, returning it. The caller is responsible for
386 freeing the string. */
389 type_to_string (struct type
*type
)
395 type_print (type
, "", &stb
, -1);
396 return std::move (stb
.string ());
398 catch (const gdb_exception
&except
)
405 /* See typeprint.h. */
408 type_print_unknown_return_type (struct ui_file
*stream
)
410 fprintf_styled (stream
, metadata_style
.style (),
411 _("<unknown return type>"));
414 /* See typeprint.h. */
417 error_unknown_type (const char *sym_print_name
)
419 error (_("'%s' has unknown type; cast it to its declared type"),
423 /* Print type of EXP, or last thing in value history if EXP == NULL.
424 show is passed to type_print. */
427 whatis_exp (const char *exp
, int show
)
430 struct type
*real_type
= NULL
;
435 struct value_print_options opts
;
436 struct type_print_options flags
= default_ptype_flags
;
444 for (++exp
; *exp
&& !isspace (*exp
); ++exp
)
452 flags
.print_methods
= 0;
455 flags
.print_methods
= 1;
458 flags
.print_typedefs
= 0;
461 flags
.print_typedefs
= 1;
465 /* Filter out languages which don't implement the
468 && (current_language
->la_language
== language_c
469 || current_language
->la_language
== language_cplus
470 || current_language
->la_language
== language_rust
))
472 flags
.print_offsets
= 1;
473 flags
.print_typedefs
= 0;
474 flags
.print_methods
= 0;
479 error (_("unrecognized flag '%c'"), *exp
);
484 if (!*exp
&& !seen_one
)
485 error (_("flag expected"));
487 error (_("expected space after format"));
488 exp
= skip_spaces (exp
);
491 expression_up expr
= parse_expression (exp
);
493 /* The behavior of "whatis" depends on whether the user
494 expression names a type directly, or a language expression
495 (including variable names). If the former, then "whatis"
496 strips one level of typedefs, only. If an expression,
497 "whatis" prints the type of the expression without stripping
498 any typedef level. "ptype" always strips all levels of
500 if (show
== -1 && expr
->elts
[0].opcode
== OP_TYPE
)
502 /* The user expression names a type directly. */
503 type
= expr
->elts
[1].type
;
505 /* If this is a typedef, then find its immediate target.
506 Use check_typedef to resolve stubs, but ignore its result
507 because we do not want to dig past all typedefs. */
508 check_typedef (type
);
509 if (type
->code () == TYPE_CODE_TYPEDEF
)
510 type
= TYPE_TARGET_TYPE (type
);
512 /* If the expression is actually a type, then there's no
513 value to fetch the dynamic type from. */
518 /* The user expression names a type indirectly by naming an
519 object or expression of that type. Find that
520 indirectly-named type. */
521 val
= evaluate_type (expr
.get ());
522 type
= value_type (val
);
527 val
= access_value_history (0);
528 type
= value_type (val
);
531 get_user_print_options (&opts
);
532 if (val
!= NULL
&& opts
.objectprint
)
534 if (((type
->code () == TYPE_CODE_PTR
) || TYPE_IS_REFERENCE (type
))
535 && (TYPE_TARGET_TYPE (type
)->code () == TYPE_CODE_STRUCT
))
536 real_type
= value_rtti_indirect_type (val
, &full
, &top
, &using_enc
);
537 else if (type
->code () == TYPE_CODE_STRUCT
)
538 real_type
= value_rtti_type (val
, &full
, &top
, &using_enc
);
541 if (flags
.print_offsets
542 && (type
->code () == TYPE_CODE_STRUCT
543 || type
->code () == TYPE_CODE_UNION
))
544 fprintf_filtered (gdb_stdout
, "/* offset | size */ ");
546 printf_filtered ("type = ");
548 std::unique_ptr
<typedef_hash_table
> table_holder
;
549 std::unique_ptr
<ext_lang_type_printers
> printer_holder
;
552 table_holder
.reset (new typedef_hash_table
);
553 flags
.global_typedefs
= table_holder
.get ();
555 printer_holder
.reset (new ext_lang_type_printers
);
556 flags
.global_printers
= printer_holder
.get ();
561 printf_filtered ("/* real type = ");
562 type_print (real_type
, "", gdb_stdout
, -1);
564 printf_filtered (" (incomplete object)");
565 printf_filtered (" */\n");
568 LA_PRINT_TYPE (type
, "", gdb_stdout
, show
, 0, &flags
);
569 printf_filtered ("\n");
573 whatis_command (const char *exp
, int from_tty
)
575 /* Most of the time users do not want to see all the fields
576 in a structure. If they do they can use the "ptype" command.
577 Hence the "-1" below. */
578 whatis_exp (exp
, -1);
581 /* TYPENAME is either the name of a type, or an expression. */
584 ptype_command (const char *type_name
, int from_tty
)
586 whatis_exp (type_name
, 1);
589 /* Print integral scalar data VAL, of type TYPE, onto stdio stream STREAM.
590 Used to print data from type structures in a specified type. For example,
591 array bounds may be characters or booleans in some languages, and this
592 allows the ranges to be printed in their "natural" form rather than as
593 decimal integer values.
595 FIXME: This is here simply because only the type printing routines
596 currently use it, and it wasn't clear if it really belonged somewhere
597 else (like printcmd.c). There are a lot of other gdb routines that do
598 something similar, but they are generally concerned with printing values
599 that come from the inferior in target byte order and target size. */
602 print_type_scalar (struct type
*type
, LONGEST val
, struct ui_file
*stream
)
607 type
= check_typedef (type
);
609 switch (type
->code ())
613 len
= type
->num_fields ();
614 for (i
= 0; i
< len
; i
++)
616 if (TYPE_FIELD_ENUMVAL (type
, i
) == val
)
623 fputs_filtered (TYPE_FIELD_NAME (type
, i
), stream
);
627 print_longest (stream
, 'd', 0, val
);
632 print_longest (stream
, TYPE_UNSIGNED (type
) ? 'u' : 'd', 0, val
);
636 LA_PRINT_CHAR ((unsigned char) val
, type
, stream
);
640 fprintf_filtered (stream
, val
? "TRUE" : "FALSE");
643 case TYPE_CODE_RANGE
:
644 print_type_scalar (TYPE_TARGET_TYPE (type
), val
, stream
);
647 case TYPE_CODE_UNDEF
:
649 case TYPE_CODE_ARRAY
:
650 case TYPE_CODE_STRUCT
:
651 case TYPE_CODE_UNION
:
656 case TYPE_CODE_STRING
:
657 case TYPE_CODE_ERROR
:
658 case TYPE_CODE_MEMBERPTR
:
659 case TYPE_CODE_METHODPTR
:
660 case TYPE_CODE_METHOD
:
662 case TYPE_CODE_RVALUE_REF
:
663 case TYPE_CODE_NAMESPACE
:
664 error (_("internal error: unhandled type in print_type_scalar"));
668 error (_("Invalid type code in symbol table."));
672 /* Dump details of a type specified either directly or indirectly.
673 Uses the same sort of type lookup mechanism as ptype_command()
674 and whatis_command(). */
677 maintenance_print_type (const char *type_name
, int from_tty
)
682 if (type_name
!= NULL
)
684 expression_up expr
= parse_expression (type_name
);
685 if (expr
->elts
[0].opcode
== OP_TYPE
)
687 /* The user expression names a type directly, just use that type. */
688 type
= expr
->elts
[1].type
;
692 /* The user expression may name a type indirectly by naming an
693 object of that type. Find that indirectly named type. */
694 val
= evaluate_type (expr
.get ());
695 type
= value_type (val
);
699 recursive_dump_type (type
, 0);
705 struct cmd_list_element
*setprinttypelist
;
707 struct cmd_list_element
*showprinttypelist
;
709 static bool print_methods
= true;
712 set_print_type_methods (const char *args
,
713 int from_tty
, struct cmd_list_element
*c
)
715 default_ptype_flags
.print_methods
= print_methods
;
719 show_print_type_methods (struct ui_file
*file
, int from_tty
,
720 struct cmd_list_element
*c
, const char *value
)
722 fprintf_filtered (file
, _("Printing of methods defined in a class in %s\n"),
726 static bool print_typedefs
= true;
729 set_print_type_typedefs (const char *args
,
730 int from_tty
, struct cmd_list_element
*c
)
732 default_ptype_flags
.print_typedefs
= print_typedefs
;
736 show_print_type_typedefs (struct ui_file
*file
, int from_tty
,
737 struct cmd_list_element
*c
, const char *value
)
739 fprintf_filtered (file
, _("Printing of typedefs defined in a class in %s\n"),
743 /* Limit on the number of nested type definitions to print or -1 to print
744 all nested type definitions in a class. By default, we do not print
745 nested definitions. */
747 static int print_nested_type_limit
= 0;
749 /* Set how many nested type definitions should be printed by the type
753 set_print_type_nested_types (const char *args
, int from_tty
,
754 struct cmd_list_element
*c
)
756 default_ptype_flags
.print_nested_type_limit
= print_nested_type_limit
;
759 /* Show how many nested type definitions the type printer will print. */
762 show_print_type_nested_types (struct ui_file
*file
, int from_tty
,
763 struct cmd_list_element
*c
, const char *value
)
767 fprintf_filtered (file
,
768 _("Will not print nested types defined in a class\n"));
772 fprintf_filtered (file
,
773 _("Will print %s nested types defined in a class\n"),
778 void _initialize_typeprint ();
780 _initialize_typeprint ()
782 struct cmd_list_element
*c
;
784 c
= add_com ("ptype", class_vars
, ptype_command
, _("\
785 Print definition of type TYPE.\n\
786 Usage: ptype[/FLAGS] TYPE | EXPRESSION\n\
787 Argument may be any type (for example a type name defined by typedef,\n\
788 or \"struct STRUCT-TAG\" or \"class CLASS-NAME\" or \"union UNION-TAG\"\n\
789 or \"enum ENUM-TAG\") or an expression.\n\
790 The selected stack frame's lexical context is used to look up the name.\n\
791 Contrary to \"whatis\", \"ptype\" always unrolls any typedefs.\n\
793 Available FLAGS are:\n\
794 /r print in \"raw\" form; do not substitute typedefs\n\
795 /m do not print methods defined in a class\n\
796 /M print methods defined in a class\n\
797 /t do not print typedefs defined in a class\n\
798 /T print typedefs defined in a class\n\
799 /o print offsets and sizes of fields in a struct (like pahole)"));
800 set_cmd_completer (c
, expression_completer
);
802 c
= add_com ("whatis", class_vars
, whatis_command
,
803 _("Print data type of expression EXP.\n\
804 Only one level of typedefs is unrolled. See also \"ptype\"."));
805 set_cmd_completer (c
, expression_completer
);
807 add_show_prefix_cmd ("type", no_class
,
808 _("Generic command for showing type-printing settings."),
809 &showprinttypelist
, "show print type ", 0,
811 add_basic_prefix_cmd ("type", no_class
,
812 _("Generic command for setting how types print."),
813 &setprinttypelist
, "set print type ", 0,
816 add_setshow_boolean_cmd ("methods", no_class
, &print_methods
,
818 Set printing of methods defined in classes."), _("\
819 Show printing of methods defined in classes."), NULL
,
820 set_print_type_methods
,
821 show_print_type_methods
,
822 &setprinttypelist
, &showprinttypelist
);
823 add_setshow_boolean_cmd ("typedefs", no_class
, &print_typedefs
,
825 Set printing of typedefs defined in classes."), _("\
826 Show printing of typedefs defined in classes."), NULL
,
827 set_print_type_typedefs
,
828 show_print_type_typedefs
,
829 &setprinttypelist
, &showprinttypelist
);
831 add_setshow_zuinteger_unlimited_cmd ("nested-type-limit", no_class
,
832 &print_nested_type_limit
,
834 Set the number of recursive nested type definitions to print \
835 (\"unlimited\" or -1 to show all)."), _("\
836 Show the number of recursive nested type definitions to print."), NULL
,
837 set_print_type_nested_types
,
838 show_print_type_nested_types
,
839 &setprinttypelist
, &showprinttypelist
);
842 /* Print <not allocated> status to stream STREAM. */
845 val_print_not_allocated (struct ui_file
*stream
)
847 fprintf_styled (stream
, metadata_style
.style (), _("<not allocated>"));
850 /* Print <not associated> status to stream STREAM. */
853 val_print_not_associated (struct ui_file
*stream
)
855 fprintf_styled (stream
, metadata_style
.style (), _("<not associated>"));