dwarfout.c

GUN开源阻止下的编译器GCC

/* Output Dwarf format symbol table information from the GNU C compiler.
   Copyright (C) 1992, 1993, 1995 Free Software Foundation, Inc.

   Written by Ron Guilmette ([e-mail]) for
   Network Computing Devices, August, September, October, November 1990.
   Generously contributed by NCD to the Free Software Foundation.

This file is part of GNU CC.

GNU CC 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 2, or (at your option)
any later version.

GNU CC 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 GNU CC; see the file COPYING.  If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

#include "config.h"

#ifdef DWARF_DEBUGGING_INFO
#include <stdio.h>
#include "dwarf.h"
#include "tree.h"
#include "flags.h"
#include "rtl.h"
#include "hard-reg-set.h"
#include "insn-config.h"
#include "reload.h"
#include "output.h"
#include "defaults.h"

#ifndef DWARF_VERSION
#define DWARF_VERSION 1
#endif

/* #define NDEBUG 1 */
#include "assert.h"

#if defined(DWARF_TIMESTAMPS)
#if defined(POSIX)
#include <time.h>
#else /* !defined(POSIX) */
#include <sys/types.h>
#if defined(__STDC__)
extern time_t time (time_t *);
#else /* !defined(__STDC__) */
extern time_t time ();
#endif /* !defined(__STDC__) */
#endif /* !defined(POSIX) */
#endif /* defined(DWARF_TIMESTAMPS) */

extern char *getpwd ();

extern char *index ();
extern char *rindex ();

/* IMPORTANT NOTE: Please see the file README.DWARF for important details
   regarding the GNU implementation of Dwarf.  */

/* NOTE: In the comments in this file, many references are made to
   so called "Debugging Information Entries".  For the sake of brevity,
   this term is abbreviated to `DIE' throughout the remainder of this
   file.  */

/* Note that the implementation of C++ support herein is (as yet) unfinished.
   If you want to try to complete it, more power to you.  */

#if defined(__GNUC__) && (NDEBUG == 1)
#define inline static inline
#else
#define inline static
#endif

/* How to start an assembler comment.  */
#ifndef ASM_COMMENT_START
#define ASM_COMMENT_START ";#"
#endif

/* How to print out a register name.  */
#ifndef PRINT_REG
#define PRINT_REG(RTX, CODE, FILE) \
  fprintf ((FILE), "%s", reg_names[REGNO (RTX)])
#endif

/* Define a macro which returns non-zero for any tagged type which is
   used (directly or indirectly) in the specification of either some
   function's return type or some formal parameter of some function.
   We use this macro when we are operating in "terse" mode to help us
   know what tagged types have to be represented in Dwarf (even in
   terse mode) and which ones don't.

   A flag bit with this meaning really should be a part of the normal
   GCC ..._TYPE nodes, but at the moment, there is no such bit defined
   for these nodes.  For now, we have to just fake it.  It it safe for
   us to simply return zero for all complete tagged types (which will
   get forced out anyway if they were used in the specification of some
   formal or return type) and non-zero for all incomplete tagged types.
*/

#define TYPE_USED_FOR_FUNCTION(tagged_type) (TYPE_SIZE (tagged_type) == 0)

extern int flag_traditional;
extern char *version_string;
extern char *language_string;

/* Maximum size (in bytes) of an artificially generated label.	*/

#define MAX_ARTIFICIAL_LABEL_BYTES	30

/* Make sure we know the sizes of the various types dwarf can describe.
   These are only defaults.  If the sizes are different for your target,
   you should override these values by defining the appropriate symbols
   in your tm.h file.  */

#ifndef CHAR_TYPE_SIZE
#define CHAR_TYPE_SIZE BITS_PER_UNIT
#endif

#ifndef SHORT_TYPE_SIZE
#define SHORT_TYPE_SIZE (BITS_PER_UNIT * 2)
#endif

#ifndef INT_TYPE_SIZE
#define INT_TYPE_SIZE BITS_PER_WORD
#endif

#ifndef LONG_TYPE_SIZE
#define LONG_TYPE_SIZE BITS_PER_WORD
#endif

#ifndef LONG_LONG_TYPE_SIZE
#define LONG_LONG_TYPE_SIZE (BITS_PER_WORD * 2)
#endif

#ifndef WCHAR_TYPE_SIZE
#define WCHAR_TYPE_SIZE INT_TYPE_SIZE
#endif

#ifndef WCHAR_UNSIGNED
#define WCHAR_UNSIGNED 0
#endif

#ifndef FLOAT_TYPE_SIZE
#define FLOAT_TYPE_SIZE BITS_PER_WORD
#endif

#ifndef DOUBLE_TYPE_SIZE
#define DOUBLE_TYPE_SIZE (BITS_PER_WORD * 2)
#endif

#ifndef LONG_DOUBLE_TYPE_SIZE
#define LONG_DOUBLE_TYPE_SIZE (BITS_PER_WORD * 2)
#endif

/* Structure to keep track of source filenames.  */

struct filename_entry {
  unsigned	number;
  char *	name;
};

typedef struct filename_entry filename_entry;

/* Pointer to an array of elements, each one having the structure above. */

static filename_entry *filename_table;

/* Total number of entries in the table (i.e. array) pointed to by
   `filename_table'.  This is the *total* and includes both used and
   unused slots.  */

static unsigned ft_entries_allocated;

/* Number of entries in the filename_table which are actually in use.  */

static unsigned ft_entries;

/* Size (in elements) of increments by which we may expand the filename
   table.  Actually, a single hunk of space of this size should be enough
   for most typical programs.	 */

#define FT_ENTRIES_INCREMENT 64

/* Local pointer to the name of the main input file.  Initialized in
   dwarfout_init.  */

static char *primary_filename;

/* Pointer to the most recent filename for which we produced some line info.  */

static char *last_filename;

/* For Dwarf output, we must assign lexical-blocks id numbers
   in the order in which their beginnings are encountered.
   We output Dwarf debugging info that refers to the beginnings
   and ends of the ranges of code for each lexical block with
   assembler labels ..Bn and ..Bn.e, where n is the block number.
   The labels themselves are generated in final.c, which assigns
   numbers to the blocks in the same way.  */

static unsigned next_block_number = 2;

/* Counter to generate unique names for DIEs. */

static unsigned next_unused_dienum = 1;

/* Number of the DIE which is currently being generated.  */

static unsigned current_dienum;

/* Number to use for the special "pubname" label on the next DIE which
   represents a function or data object defined in this compilation
   unit which has "extern" linkage.  */

static next_pubname_number = 0;

#define NEXT_DIE_NUM pending_sibling_stack[pending_siblings-1]

/* Pointer to a dynamically allocated list of pre-reserved and still
   pending sibling DIE numbers.	 Note that this list will grow as needed.  */

static unsigned *pending_sibling_stack;

/* Counter to keep track of the number of pre-reserved and still pending
   sibling DIE numbers.	 */

static unsigned pending_siblings;

/* The currently allocated size of the above list (expressed in number of
   list elements).  */

static unsigned pending_siblings_allocated;

/* Size (in elements) of increments by which we may expand the pending
   sibling stack.  Actually, a single hunk of space of this size should
   be enough for most typical programs.	 */

#define PENDING_SIBLINGS_INCREMENT 64

/* Non-zero if we are performing our file-scope finalization pass and if
   we should force out Dwarf descriptions of any and all file-scope
   tagged types which are still incomplete types.  */

static int finalizing = 0;

/* A pointer to the base of a list of pending types which we haven't
   generated DIEs for yet, but which we will have to come back to
   later on.  */

static tree *pending_types_list;

/* Number of elements currently allocated for the pending_types_list.  */

static unsigned pending_types_allocated;

/* Number of elements of pending_types_list currently in use.  */

static unsigned pending_types;

/* Size (in elements) of increments by which we may expand the pending
   types list.  Actually, a single hunk of space of this size should
   be enough for most typical programs.	 */

#define PENDING_TYPES_INCREMENT 64

/* Pointer to an artificial RECORD_TYPE which we create in dwarfout_init.
   This is used in a hack to help us get the DIEs describing types of
   formal parameters to come *after* all of the DIEs describing the formal
   parameters themselves.  That's necessary in order to be compatible
   with what the brain-damaged svr4 SDB debugger requires.  */

static tree fake_containing_scope;

/* The number of the current function definition that we are generating
   debugging information for.  These numbers range from 1 up to the maximum
   number of function definitions contained within the current compilation
   unit.  These numbers are used to create unique labels for various things
   contained within various function definitions.  */

static unsigned current_funcdef_number = 1;

/* A pointer to the ..._DECL node which we have most recently been working
   on.  We keep this around just in case something about it looks screwy
   and we want to tell the user what the source coordinates for the actual
   declaration are.  */

static tree dwarf_last_decl;

/* Forward declarations for functions defined in this file.  */

static void output_type ();
static void type_attribute ();
static void output_decls_for_scope ();
static void output_decl ();
static unsigned lookup_filename ();

/* Definitions of defaults for assembler-dependent names of various
   pseudo-ops and section names.

   Theses may be overridden in your tm.h file (if necessary) for your
   particular assembler.  The default values provided here correspond to
   what is expected by "standard" AT&T System V.4 assemblers.  */

#ifndef FILE_ASM_OP
#define FILE_ASM_OP		".file"
#endif
#ifndef VERSION_ASM_OP
#define VERSION_ASM_OP		".version"
#endif
#ifndef UNALIGNED_SHORT_ASM_OP
#define UNALIGNED_SHORT_ASM_OP	".2byte"
#endif
#ifndef UNALIGNED_INT_ASM_OP
#define UNALIGNED_INT_ASM_OP	".4byte"
#endif
#ifndef ASM_BYTE_OP
#define ASM_BYTE_OP		".byte"
#endif
#ifndef SET_ASM_OP
#define SET_ASM_OP		".set"
#endif

/* Pseudo-ops for pushing the current section onto the section stack (and
   simultaneously changing to a new section) and for poping back to the
   section we were in immediately before this one.  Note that most svr4
   assemblers only maintain a one level stack... you can push all the
   sections you want, but you can only pop out one level.  (The sparc
   svr4 assembler is an exception to this general rule.)  That's
   OK because we only use at most one level of the section stack herein.  */

#ifndef PUSHSECTION_ASM_OP
#define PUSHSECTION_ASM_OP	".section"
#endif
#ifndef POPSECTION_ASM_OP
#define POPSECTION_ASM_OP	".previous"
#endif

/* The default format used by the ASM_OUTPUT_PUSH_SECTION macro (see below)
   to print the PUSHSECTION_ASM_OP and the section name.  The default here
   works for almost all svr4 assemblers, except for the sparc, where the
   section name must be enclosed in double quotes.  (See sparcv4.h.)  */

#ifndef PUSHSECTION_FORMAT
#define PUSHSECTION_FORMAT	"\t%s\t%s\n"
#endif

#ifndef DEBUG_SECTION
#define DEBUG_SECTION		".debug"
#endif
#ifndef LINE_SECTION
#define LINE_SECTION		".line"
#endif
#ifndef SFNAMES_SECTION
#define SFNAMES_SECTION		".debug_sfnames"
#endif
#ifndef SRCINFO_SECTION
#define SRCINFO_SECTION		".debug_srcinfo"
#endif
#ifndef MACINFO_SECTION
#define MACINFO_SECTION		".debug_macinfo"
#endif
#ifndef PUBNAMES_SECTION
#define PUBNAMES_SECTION	".debug_pubnames"
#endif
#ifndef ARANGES_SECTION
#define ARANGES_SECTION		".debug_aranges"
#endif
#ifndef TEXT_SECTION
#define TEXT_SECTION		".text"
#endif
#ifndef DATA_SECTION
#define DATA_SECTION		".data"
#endif
#ifndef DATA1_SECTION
#define DATA1_SECTION		".data1"
#endif
#ifndef RODATA_SECTION
#define RODATA_SECTION		".rodata"
#endif
#ifndef RODATA1_SECTION
#define RODATA1_SECTION		".rodata1"
#endif
#ifndef BSS_SECTION
#define BSS_SECTION		".bss"
#endif

/* Definitions of defaults for formats and names of various special
   (artificial) labels which may be generated within this file (when
   the -g options is used and DWARF_DEBUGGING_INFO is in effect.

   If necessary, these may be overridden from within your tm.h file,
   but typically, you should never need to override these.

   These labels have been hacked (temporarily) so that they all begin with
   a `.L' sequence so as to appease the stock sparc/svr4 assembler and the