mipsread.c

早期freebsd实现

	val = bfd_read((PTR)&filhdr, sizeof filhdr, 1, abfd);

	if (end_of_text_segp)
		*end_of_text_segp =
			bfd_h_get_32 (abfd, filhdr.a.text_start) +
			bfd_h_get_32 (abfd, filhdr.a.tsize);

	/* Find and read the symbol table header */
	st_hdrsize = bfd_h_get_32 (abfd, filhdr.f.f_nsyms);
	st_filptr  = bfd_h_get_32 (abfd, filhdr.f.f_symptr);
	if (st_filptr == 0)
		return;

	bfd_seek (abfd, st_filptr, L_SET);
	if (st_hdrsize != sizeof (hdr_ext)) {	/* Profanity check */
		error ("Wrong header size: %d, not %d", st_hdrsize,
			sizeof (hdr_ext));
	}
	if (bfd_read((PTR)&hdr_ext, st_hdrsize, 1, abfd) != st_hdrsize)
		goto readerr;
	ecoff_swap_hdr_in (abfd, &hdr_ext, &st_hdr);

	/* Find out how large the symbol table is */
	stsize = (st_hdr.cbExtOffset - (st_filptr + st_hdrsize))
		+ st_hdr.iextMax * cbEXTR;

	/* Allocate space for the symbol table.  Read it in.  */
	cur_hdr = (HDRR *) xmalloc(stsize + st_hdrsize);

	memcpy((PTR)cur_hdr, (PTR)&hdr_ext, st_hdrsize);
	if (bfd_read((char *)cur_hdr + st_hdrsize, stsize, 1, abfd) != stsize)
		goto readerr;

	/* Fixup file_pointers in it */
	fixup_symtab(cur_hdr, (char *) cur_hdr + st_hdrsize,
		     st_filptr + st_hdrsize, abfd);

	return;
readerr:
	error("Short read on %s", bfd_get_filename (abfd));
}


/* Turn all file-relative pointers in the symtab described by HDR
   into memory pointers, given that the symtab itself is located
   at DATA in memory and F_PTR in the file.

   Byte-swap all the data structures, in place, while we are at it --
   except AUX entries, which we leave in their original byte order.
   They will be swapped as they are used instead.  (FIXME:  we ought to
   do all the data structures that way.)  */

static void
fixup_symtab (hdr, data, f_ptr, abfd)
	HDRR *hdr;
	char *data;
	file_ptr f_ptr;
	bfd *abfd;
{
	int             f_idx, s_idx, i;
	FDR            *fh;
	SYMR	       *sh;
	PDR	       *pr;
	EXTR	       *esh;
	struct rfd_ext *rbase;

	/* This function depends on the external and internal forms
	   of the MIPS symbol table taking identical space.  Check this
	   assumption at compile-time.  
	   DO NOT DELETE THESE ENTRIES, OR COMMENT THEM OUT, JUST BECAUSE SOME
	   "LINT" OR COMPILER THINKS THEY ARE UNUSED!  Thank you.  */
	static check_hdr1[1 + sizeof (struct hdr_ext) - sizeof (HDRR)] = {0};
	static check_hdr2[1 + sizeof (HDRR) - sizeof (struct hdr_ext)] = {0};
	static check_fdr1[1 + sizeof (struct fdr_ext) - sizeof (FDR)] = {0};
	static check_fdr2[1 + sizeof (FDR) - sizeof (struct fdr_ext)] = {0};
	static check_pdr1[1 + sizeof (struct pdr_ext) - sizeof (PDR)] = {0};
	static check_pdr2[1 + sizeof (PDR) - sizeof (struct pdr_ext)] = {0};
	static check_sym1[1 + sizeof (struct sym_ext) - sizeof (SYMR)] = {0};
	static check_sym2[1 + sizeof (SYMR) - sizeof (struct sym_ext)] = {0};
	static check_ext1[1 + sizeof (struct ext_ext) - sizeof (EXTR)] = {0};
	static check_ext2[1 + sizeof (EXTR) - sizeof (struct ext_ext)] = {0};
	static check_rfd1[1 + sizeof (struct rfd_ext) - sizeof (RFDT)] = {0};
	static check_rfd2[1 + sizeof (RFDT) - sizeof (struct rfd_ext)] = {0};

	/* Swap in the header record.  */
	ecoff_swap_hdr_in (abfd, hdr, hdr);

	/*
	 * These fields are useless (and empty) by now:
	 *	hdr->cbDnOffset, hdr->cbOptOffset
	 * We use them for other internal purposes.
	 */
	hdr->cbDnOffset = 0;
	hdr->cbOptOffset = 0;

#define FIX(off) \
	if (hdr->off) hdr->off = (unsigned int)data + (hdr->off - f_ptr);

	FIX(cbLineOffset);
	FIX(cbPdOffset);
	FIX(cbSymOffset);
	FIX(cbOptOffset);
	FIX(cbAuxOffset);
	FIX(cbSsOffset);
	FIX(cbSsExtOffset);
	FIX(cbFdOffset);
	FIX(cbRfdOffset);
	FIX(cbExtOffset);
#undef	FIX

	/* Fix all the RFD's.  */
	rbase = (struct rfd_ext *)(hdr->cbRfdOffset);
	for (i = 0; i < hdr->crfd; i++) {
	  ecoff_swap_rfd_in (abfd, rbase+i, (pRFDT) rbase+i);
	}

	/* Fix all string pointers inside the symtab, and
	   the FDR records.  Also fix other miscellany.  */

	for (f_idx = 0; f_idx < hdr->ifdMax; f_idx++) {
		register unsigned code_offset;

		/* Header itself, and strings */
		fh = (FDR *) (hdr->cbFdOffset) + f_idx;

		/* Swap in the FDR */
		ecoff_swap_fdr_in (abfd, fh, fh);

		fh->issBase += hdr->cbSsOffset;
		if (fh->rss != -1)
			fh->rss = (long)fh->rss + fh->issBase;

		/* Local symbols */
		fh->isymBase = (int)((SYMR*)(hdr->cbSymOffset)+fh->isymBase);

		/* FIXME! Probably don't want to do this here! */
		for (s_idx = 0; s_idx < fh->csym; s_idx++) {
			sh = (SYMR*)fh->isymBase + s_idx;
			ecoff_swap_sym_in (abfd, sh, sh);

			sh->iss = (long) sh->iss + fh->issBase;
			sh->reserved = 0;
		}

		cur_fd = f_idx;

		/* cannot fix fh->ipdFirst because it is a short */
#define IPDFIRST(h,fh) \
		((long)h->cbPdOffset + fh->ipdFirst * sizeof(PDR))

		/* Optional symbols (actually used for partial_symtabs) */
		fh->ioptBase = 0;
		fh->copt = 0;

		/* Aux symbols */
		if (fh->caux)
			fh->iauxBase = hdr->cbAuxOffset + fh->iauxBase * sizeof(union aux_ext);
		/* Relative file descriptor table */
		fh->rfdBase = hdr->cbRfdOffset + fh->rfdBase * sizeof(RFDT);

		/* Line numbers */
		if (fh->cbLine)
			fh->cbLineOffset += hdr->cbLineOffset;

		/* Procedure symbols.  (XXX This should be done later) */
		code_offset = fh->adr;
		for (s_idx = 0; s_idx < fh->cpd; s_idx++) {
			unsigned name, only_ext;

			pr = (PDR*)(IPDFIRST(hdr,fh)) + s_idx;
			ecoff_swap_pdr_in (abfd, pr, pr);

			/* Simple rule to find files linked "-x" */
			only_ext = fh->rss == -1;
			if (only_ext) {
				if (pr->isym == -1) {
					/* static function */
					sh = (SYMR*)-1;
				} else {
					/* external */
					name = hdr->cbExtOffset + pr->isym * sizeof(EXTR);
					sh = &((EXTR*)name)->asym;
				}
			} else {
				/* Full symbols */
				sh = (SYMR*)fh->isymBase + pr->isym;
				/* Included code ? */
				if (s_idx == 0 && pr->adr != 0)
					code_offset -= pr->adr;
			}

			/* Turn index into a pointer */
			pr->isym = (long)sh;

			/* Fix line numbers */
			pr->cbLineOffset += fh->cbLineOffset;

			/* Relocate address */
			if (!only_ext)
				pr->adr += code_offset;
		}
	}

	/* External symbols: swap in, and fix string */
	for (s_idx = 0; s_idx < hdr->iextMax; s_idx++) {
		esh = (EXTR*)(hdr->cbExtOffset) + s_idx;
		ecoff_swap_ext_in (abfd, esh, esh);
		esh->asym.iss = esh->asym.iss + hdr->cbSsExtOffset;
	}
}


/* Find a file descriptor given its index RF relative to a file CF */

static FDR *
get_rfd (cf, rf)
	int cf, rf;
{
	register FDR   *f;

	f = (FDR *) (cur_hdr->cbFdOffset) + cf;
	/* Object files do not have the RFD table, all refs are absolute */
	if (f->rfdBase == 0)
		return (FDR *) (cur_hdr->cbFdOffset) + rf;
	cf = *((pRFDT) f->rfdBase + rf);
	return (FDR *) (cur_hdr->cbFdOffset) + cf;
}

/* Return a safer print NAME for a file descriptor */

static char *
fdr_name(name)
	char *name;
{
	if (name == (char *) -1)
		return "<stripped file>";
	if (UNSAFE_DATA_ADDR(name))
		return "<NFY>";
	return name;
}


/* Read in and parse the symtab of the file OBJFILE.  Symbols from
   different sections are relocated via the SECTION_OFFSETS.  */

static void
read_mips_symtab (objfile, section_offsets)
	struct objfile *objfile;
	struct section_offsets *section_offsets;
{
	CORE_ADDR end_of_text_seg;

	read_the_mips_symtab(objfile->obfd, &end_of_text_seg);

	parse_partial_symbols(end_of_text_seg, objfile, section_offsets);

#if 0
	/*
	 * Check to make sure file was compiled with -g.
	 * If not, warn the user of this limitation.
	 */
	if (compare_glevel(max_glevel, GLEVEL_2) < 0) {
		if (max_gdbinfo == 0)
			printf (
"\n%s not compiled with -g, debugging support is limited.\n",
				objfile->name);
		printf(
"You should compile with -g2 or -g3 for best debugging support.\n");
		fflush(stdout);
	}
#endif
}

/* Local utilities */

/* Map of FDR indexes to partial symtabs */

struct pst_map {
    struct partial_symtab *pst;	/* the psymtab proper */
    int n_globals; /* exported globals (external symbols) */
    int globals_offset;  /* cumulative */
};


/* Utility stack, used to nest procedures and blocks properly.
   It is a doubly linked list, to avoid too many alloc/free.
   Since we might need it quite a few times it is NOT deallocated
   after use. */

static struct parse_stack {
    struct parse_stack	*next, *prev;
    struct symtab	*cur_st;	/* Current symtab. */
    struct block	*cur_block;	/* Block in it. */
    int			 blocktype;	/* What are we parsing. */
    int			 maxsyms;	/* Max symbols in this block. */
    struct type		*cur_type;	/* Type we parse fields for. */
    int			 cur_field;	/* Field number in cur_type. */
    int			 procadr;	/* Start addres of this procedure */
    int			 numargs;	/* Its argument count */
} *top_stack;	/* Top stack ptr */


/* Enter a new lexical context */

static void
push_parse_stack()
{
	struct parse_stack *new;

	/* Reuse frames if possible */
	if (top_stack && top_stack->prev)
		new = top_stack->prev;
	else
		new = (struct parse_stack *) xzalloc(sizeof(struct parse_stack));
	/* Initialize new frame with previous content */
	if (top_stack) {
		register struct parse_stack *prev = new->prev;

		*new = *top_stack;
		top_stack->prev = new;
		new->prev = prev;
		new->next = top_stack;
	}
	top_stack = new;
}

/* Exit a lexical context */

static void
pop_parse_stack()
{
	if (!top_stack)
		return;
	if (top_stack->next)
		top_stack = top_stack->next;
}


/* Cross-references might be to things we haven't looked at
   yet, e.g. type references.  To avoid too many type
   duplications we keep a quick fixup table, an array
   of lists of references indexed by file descriptor */

static struct mips_pending {
	struct mips_pending	*next;		/* link */
	SYMR		*s;		/* the symbol */
	struct type	*t;		/* its partial type descriptor */
} **pending_list;


/* Check whether we already saw symbol SH in file FH as undefined */

static struct mips_pending *
is_pending_symbol(fh, sh)
	FDR *fh;
	SYMR *sh;
{
	int             f_idx = fh - (FDR *) cur_hdr->cbFdOffset;
	register struct mips_pending *p;

	/* Linear search is ok, list is typically no more than 10 deep */
	for (p = pending_list[f_idx]; p; p = p->next)
		if (p->s == sh)
			break;
	return p;
}

/* Add a new undef symbol SH of type T */

static void
add_pending(fh, sh, t)
	FDR *fh;
	SYMR *sh;
	struct type *t;
{
	int             f_idx = fh - (FDR *) cur_hdr->cbFdOffset;
	struct mips_pending *p = is_pending_symbol(fh, sh);

	/* Make sure we do not make duplicates */
	if (!p) {
		p = (struct mips_pending *) xmalloc(sizeof(*p));
		p->s = sh;
		p->t = t;
		p->next = pending_list[f_idx];
		pending_list[f_idx] = p;
	}
	sh->reserved = 1;	/* for quick check */
}

/* Throw away undef entries when done with file index F_IDX */
/* FIXME -- storage leak.  This is never called!!!   --gnu */

#if 0

static void
free_pending(f_idx)
	int f_idx;
{
	register struct mips_pending *p, *q;

	for (p = pending_list[f_idx]; p; p = q) {
		q = p->next;
		free((PTR)p);
	}
	pending_list[f_idx] = 0;
}

#endif

static char *
prepend_tag_kind(tag_name, type_code)
     char *tag_name;
     enum type_code type_code;
{
    char *prefix;
    char *result;
    switch (type_code) {
      case TYPE_CODE_ENUM:
	prefix = "enum ";
	break;
      case TYPE_CODE_STRUCT:
	prefix = "struct ";
	break;
      case TYPE_CODE_UNION:
	prefix = "union ";
	break;
      default:
	prefix = "";
    }

    result = (char*)obstack_alloc (&current_objfile->symbol_obstack,
				   strlen(prefix) + strlen(tag_name) + 1);
    sprintf(result, "%s%s", prefix, tag_name);
    return result;
}


/* Parsing Routines proper. */

/* Parse a single symbol. Mostly just make up a GDB symbol for it.
   For blocks, procedures and types we open a new lexical context.
   This is basically just a big switch on the symbol's type.
   Argument AX is the base pointer of aux symbols for this file (fh->iauxBase).
   BIGEND says whether aux symbols are big-endian or little-endian.
   Return count of SYMR's handled (normally one). */

static int
parse_symbol(sh, ax, bigend)
	SYMR *sh;
	union aux_ext *ax;
	int bigend;
{
	char *name;
	struct symbol  *s;
	struct block   *b;
	struct type    *t;
	struct field   *f;
	int count = 1;
	/* When a symbol is cross-referenced from other files/symbols