binutils-gdb/gdb/valprint.h
Pedro Alves 782d47dfbd Fix "info frame" in the outermost frame.
Doing "info frame" in the outermost frame, when that was indicated by
the next frame saying the unwound PC is undefined/not saved, results
in error and incomplete output:

 (gdb) bt
 #0  thread_function0 (arg=0x0) at threads.c:63
 #1  0x00000034cf407d14 in start_thread (arg=0x7ffff7fcb700) at pthread_create.c:309
 #2  0x000000323d4f168d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:115

 (gdb) frame 2
 #2  0x000000323d4f168d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:115
 115             call    *%rax

 (gdb) info frame
 Stack level 2, frame at 0x0:
  rip = 0x323d4f168d in clone (../sysdeps/unix/sysv/linux/x86_64/clone.S:115); saved rip Register 16 was not saved
 (gdb)

Not saved register values are treated as optimized out values
internally throughout.  stack.c:frame_info is handing unvailable
values, but not optimized out ones.  The patch deletes the
frame_unwind_caller_pc_if_available wrapper function and instead lets
errors propagate to frame_info (it's only user).

As frame_unwind_pc now needs to be able to handle and cache two
different error scenarios, the prev_pc.p variable is replaced with an
enumeration.

(FWIW, I looked into making gdbarch_unwind_pc or a variant return
struct value's instead, but it results in lots of boxing and unboxing
for no real gain -- e.g., the mips and arm implementations need to do
computation on the unboxed PC value.  Might as well throw an error on
first attempt to get at invalid contents.)

After the patch, we get:

 (gdb) info frame
 Stack level 2, frame at 0x0:
  rip = 0x323d4f168d in clone (../sysdeps/unix/sysv/linux/x86_64/clone.S:115); saved rip = <not saved>
  Outermost frame: outermost
  caller of frame at 0x7ffff7fcafc0
  source language asm.
  Arglist at 0x7ffff7fcafb8, args:
  Locals at 0x7ffff7fcafb8, Previous frame's sp is 0x7ffff7fcafc8
 (gdb)

A new test is added.  It's based off dw2-reg-undefined.exp, and tweaked to
mark the return address (rip) of "stop_frame" as undefined.

Tested on x86_64 Fedora 17.

gdb/
2013-12-06  Pedro Alves  <palves@redhat.com>

	* frame.c (enum cached_copy_status): New enum.
	(struct frame_info) <prev_pc.p>: Change type to enum
	cached_copy_status.
	(fprint_frame): Handle not saved and unavailable prev_pc values.
	(frame_unwind_pc_if_available): Delete and merge contents into ...
	(frame_unwind_pc): ... here.  Handle OPTIMIZED_OUT_ERROR.  Adjust
	to use enum cached_copy_status.
	(frame_unwind_caller_pc_if_available): Delete.
	(create_new_frame): Adjust.
	* frame.h (frame_unwind_caller_pc_if_available): Delete
	declaration.
	* stack.c (frame_info): Use frame_unwind_caller_pc instead of
	frame_unwind_caller_pc_if_available, and handle
	NOT_AVAILABLE_ERROR and OPTIMIZED_OUT_ERROR errors.
	* valprint.c (val_print_optimized_out): Use val_print_not_saved.
	(val_print_not_saved): New function.
	* valprint.h (val_print_not_saved): Declare.

gdb/testsuite/
2013-12-06  Pedro Alves  <palves@redhat.com>

	* gdb.dwarf2/dw2-undefined-ret-addr.S: New file.
	* gdb.dwarf2/dw2-undefined-ret-addr.c: New file.
	* gdb.dwarf2/dw2-undefined-ret-addr.exp: New file.
2013-12-06 19:50:10 +00:00

221 lines
7.2 KiB
C

/* Declarations for value printing routines for GDB, the GNU debugger.
Copyright (C) 1986-2013 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#ifndef VALPRINT_H
#define VALPRINT_H
/* This is used to pass formatting options to various value-printing
functions. */
struct value_print_options
{
/* Pretty-formatting control. */
enum val_prettyformat prettyformat;
/* Controls pretty formatting of arrays. */
int prettyformat_arrays;
/* Controls pretty formatting of structures. */
int prettyformat_structs;
/* Controls printing of virtual tables. */
int vtblprint;
/* Controls printing of nested unions. */
int unionprint;
/* Controls printing of addresses. */
int addressprint;
/* Controls looking up an object's derived type using what we find
in its vtables. */
int objectprint;
/* Maximum number of chars to print for a string pointer value or vector
contents, or UINT_MAX for no limit. Note that "set print elements 0"
stores UINT_MAX in print_max, which displays in a show command as
"unlimited". */
unsigned int print_max;
/* Print repeat counts if there are more than this many repetitions
of an element in an array. */
unsigned int repeat_count_threshold;
/* The global output format letter. */
int output_format;
/* The current format letter. This is set locally for a given call,
e.g. when the user passes a format to "print". */
int format;
/* Stop printing at null character? */
int stop_print_at_null;
/* True if we should print the index of each element when printing
an array. */
int print_array_indexes;
/* If nonzero, then dereference references, otherwise just print
them like pointers. */
int deref_ref;
/* If nonzero, print static fields. */
int static_field_print;
/* If nonzero, print static fields for Pascal. FIXME: C++ and Java
share one flag, why not Pascal too? */
int pascal_static_field_print;
/* If non-zero don't do Python pretty-printing. */
int raw;
/* If nonzero, print the value in "summary" form.
If raw and summary are both non-zero, don't print non-scalar values
("..." is printed instead). */
int summary;
/* If nonzero, when printing a pointer, print the symbol to which it
points, if any. */
int symbol_print;
};
/* The global print options set by the user. In general this should
not be directly accessed, except by set/show commands. Ordinary
code should call get_user_print_options instead. */
extern struct value_print_options user_print_options;
/* Initialize *OPTS to be a copy of the user print options. */
extern void get_user_print_options (struct value_print_options *opts);
/* Initialize *OPTS to be a copy of the user print options, but with
pretty-formatting disabled. */
extern void get_no_prettyformat_print_options (struct value_print_options *);
/* Initialize *OPTS to be a copy of the user print options, but using
FORMAT as the formatting option. */
extern void get_formatted_print_options (struct value_print_options *opts,
char format);
extern void maybe_print_array_index (struct type *index_type, LONGEST index,
struct ui_file *stream,
const struct value_print_options *);
extern void val_print_array_elements (struct type *, const gdb_byte *, int,
CORE_ADDR, struct ui_file *, int,
const struct value *,
const struct value_print_options *,
unsigned int);
extern void val_print_type_code_int (struct type *, const gdb_byte *,
struct ui_file *);
extern void val_print_type_code_flags (struct type *type,
const gdb_byte *valaddr,
struct ui_file *stream);
extern void val_print_scalar_formatted (struct type *,
const gdb_byte *, int,
const struct value *,
const struct value_print_options *,
int,
struct ui_file *);
extern void print_binary_chars (struct ui_file *, const gdb_byte *,
unsigned int, enum bfd_endian);
extern void print_octal_chars (struct ui_file *, const gdb_byte *,
unsigned int, enum bfd_endian);
extern void print_decimal_chars (struct ui_file *, const gdb_byte *,
unsigned int, enum bfd_endian);
extern void print_hex_chars (struct ui_file *, const gdb_byte *,
unsigned int, enum bfd_endian);
extern void print_char_chars (struct ui_file *, struct type *,
const gdb_byte *, unsigned int, enum bfd_endian);
extern void print_function_pointer_address (const struct value_print_options *options,
struct gdbarch *gdbarch,
CORE_ADDR address,
struct ui_file *stream);
extern int read_string (CORE_ADDR addr, int len, int width,
unsigned int fetchlimit,
enum bfd_endian byte_order, gdb_byte **buffer,
int *bytes_read);
extern void val_print_optimized_out (const struct value *val,
struct ui_file *stream);
/* Prints "<not saved>" to STREAM. */
extern void val_print_not_saved (struct ui_file *stream);
extern void val_print_unavailable (struct ui_file *stream);
extern void val_print_invalid_address (struct ui_file *stream);
/* An instance of this is passed to generic_val_print and describes
some language-specific ways to print things. */
struct generic_val_print_decorations
{
/* Printing complex numbers: what to print before, between the
elements, and after. */
const char *complex_prefix;
const char *complex_infix;
const char *complex_suffix;
/* Boolean true and false. */
const char *true_name;
const char *false_name;
/* What to print when we see TYPE_CODE_VOID. */
const char *void_name;
};
extern void generic_val_print (struct type *type, const gdb_byte *valaddr,
int embedded_offset, CORE_ADDR address,
struct ui_file *stream, int recurse,
const struct value *original_value,
const struct value_print_options *options,
const struct generic_val_print_decorations *);
extern void generic_emit_char (int c, struct type *type, struct ui_file *stream,
int quoter, const char *encoding);
extern void generic_printstr (struct ui_file *stream, struct type *type,
const gdb_byte *string, unsigned int length,
const char *encoding, int force_ellipses,
int quote_char, int c_style_terminator,
const struct value_print_options *options);
/* Run the "output" command. ARGS and FROM_TTY are the usual
arguments passed to all command implementations, except ARGS is
const. */
extern void output_command_const (const char *args, int from_tty);
extern int val_print_scalar_type_p (struct type *type);
#endif