Handle debug symbols in dynamically loaded (relocated) code:

[deliverable/binutils-gdb.git] / gdb / mipsread.c

/* Read a symbol table in MIPS' format (Third-Eye).
   Copyright 1986, 1987, 1989, 1990, 1991 Free Software Foundation, Inc.
   Contributed by Alessandro Forin (af@cs.cmu.edu) at CMU.

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 2 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, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */

/* This module provides three functions: mipscoff_symfile_init,
   which initializes to read a symbol file; mipscoff_new_init, which 
   discards existing cached information when all symbols are being
   discarded; and mipscoff_symfile_read, which reads a symbol table
   from a file.

   mipscoff_symfile_read only does the minimum work necessary for letting the
   user "name" things symbolically; it does not read the entire symtab.
   Instead, it reads the external and static symbols and puts them in partial
   symbol tables.  When more extensive information is requested of a
   file, the corresponding partial symbol table is mutated into a full
   fledged symbol table by going back and reading the symbols
   for real.  mipscoff_psymtab_to_symtab() is called indirectly through
   a pointer in the psymtab to do this.  */

#include <stdio.h>
#include "defs.h"
#include "symtab.h"
#include "gdbcore.h"
#include "symfile.h"
#include "obstack.h"
#include "buildsym.h"
#include <sys/param.h>
#include <sys/file.h>
#include <sys/stat.h>
#ifdef  CMUCS
#include <mips/syms.h>
#else /* not CMUCS */
#include <symconst.h>
#include <sym.h>
#endif /* not CMUCS */

#include "coff/mips.h"
#include "libaout.h"            /* FIXME Secret internal BFD stuff for a.out */
#include "aout/aout64.h"
#include "aout/stab_gnu.h"      /* We always use GNU stabs, not native, now */

struct coff_exec {
        struct external_filehdr f;
        struct external_aouthdr a;
};

/* These must match the corresponding definition in mips-tfile.c.
   At some point, these should probably go into an include file,
   but currently gcc does use/need the ../include directory. */

#define CODE_MASK 0x8F300
#define MIPS_IS_STAB(sym) (((sym)->index & 0xFFF00) == CODE_MASK)
#define MIPS_MARK_STAB(code) ((code)+CODE_MASK)
#define MIPS_UNMARK_STAB(code) ((code)-CODE_MASK)
#define STABS_SYMBOL "@stabs"

/* Each partial symbol table entry contains a pointer to private data for the
   read_symtab() function to use when expanding a partial symbol table entry
   to a full symbol table entry.

   For mipsread this structure contains the index of the FDR that this psymtab
   represents and a pointer to the symbol table header HDRR from the symbol
   file that the psymtab was created from.  */

#define FDR_IDX(p) (((struct symloc *)((p)->read_symtab_private))->fdr_idx)
#define CUR_HDR(p) (((struct symloc *)((p)->read_symtab_private))->cur_hdr)

struct symloc {
  int fdr_idx;
  HDRR *cur_hdr;
};

/* Things we import explicitly from other modules */

extern int           info_verbose;
extern struct block *block_for_pc();
extern void          sort_symtab_syms();

/* Various complaints about symbol reading that don't abort the process */
   
struct complaint unknown_ext_complaint = 
        {"unknown external symbol %s", 0, 0};

struct complaint unknown_sym_complaint = 
        {"unknown local symbol %s", 0, 0};

struct complaint unknown_st_complaint = 
        {"with type %d", 0, 0};

struct complaint block_overflow_complaint = 
        {"block containing %s overfilled", 0, 0};

struct complaint basic_type_complaint = 
        {"cannot map MIPS basic type 0x%x", 0, 0};

struct complaint unknown_type_qual_complaint = 
        {"unknown type qualifier 0x%x", 0, 0};

struct complaint array_bitsize_complaint = 
        {"size of array target type not known, assuming %d bits", 0, 0};

struct complaint array_parse_complaint = 
        {"array type with strange relative symbol", 0, 0};

struct complaint bad_tag_guess_complaint = 
        {"guessed tag type incorrectly", 0, 0};

/* Macros and extra defs */

/* Already-parsed symbols are marked specially */

#define stParsed stType

/* Puns: hard to find whether -g was used and how */

#define MIN_GLEVEL GLEVEL_0
#define compare_glevel(a,b)                                     \
        (((a) == GLEVEL_3) ? ((b) < GLEVEL_3) :                 \
         ((b) == GLEVEL_3) ? -1 : (int)((b) - (a)))

/* When looking at .o files, avoid tripping over bad addresses */

#define SAFE_TEXT_ADDR 0x400000
#define SAFE_DATA_ADDR 0x10000000

#define UNSAFE_DATA_ADDR(p)     ((unsigned)p < SAFE_DATA_ADDR || (unsigned)p > 2*SAFE_DATA_ADDR)
\f
/* Things that really are local to this module */

/* GDB symtable for the current compilation unit */

static struct symtab *cur_stab;

/* MIPS symtab header for the current file */

static HDRR     *cur_hdr;

/* Pointer to current file decriptor record, and its index */

static FDR      *cur_fdr;
static int       cur_fd;

/* Index of current symbol */

static int       cur_sdx;

/* Note how much "debuggable" this image is.  We would like
   to see at least one FDR with full symbols */

static max_gdbinfo;
static max_glevel;

/* When examining .o files, report on undefined symbols */

static int n_undef_symbols, n_undef_labels, n_undef_vars, n_undef_procs;

/* Pseudo symbol to use when putting stabs into the symbol table.  */

static char stabs_symbol[] = STABS_SYMBOL;

/* Extra builtin types */

struct type *builtin_type_complex;
struct type *builtin_type_double_complex;
struct type *builtin_type_fixed_dec;
struct type *builtin_type_float_dec;
struct type *builtin_type_string;

/* Forward declarations */

static struct symbol    *new_symbol();
static struct type      *new_type();
static struct block     *new_block();
static struct symtab    *new_symtab();
static struct linetable *new_linetable();
static struct blockvector *new_bvect();

static struct type      *parse_type();
static struct type      *make_type();
static struct symbol    *mylookup_symbol();
static struct block     *shrink_block();
static void sort_blocks();

static int compare_symtabs();
static int compare_psymtabs();
static int compare_blocks();

static struct partial_symtab *new_psymtab();
static struct partial_symtab *parse_fdr();
static int compare_psymbols();

static void psymtab_to_symtab_1();
static void add_block();
static void add_symbol();
static int  add_line();
static struct linetable *shrink_linetable();
static char* mips_next_symbol_text ();

\f
/* Things we export to other modules */

/* Address bounds for the signal trampoline in inferior, if any */
/* FIXME:  Nothing really seems to use this.  Why is it here? */

CORE_ADDR sigtramp_address, sigtramp_end;

/* The entry point (starting address) of the file, if it is an executable.  */

extern CORE_ADDR startup_file_start;    /* From blockframe.c */
extern CORE_ADDR startup_file_end;      /* From blockframe.c */

void
mipscoff_new_init()
{
  /* If we have a file symbol header lying around, blow it away.  */
  if (cur_hdr)
    free ((char *)cur_hdr);
  cur_hdr = 0;
}

void
mipscoff_symfile_init (sf)
     struct sym_fns *sf;
{
  sf->sym_private = NULL;
}

void
mipscoff_symfile_read(sf, addr, mainline)
     struct sym_fns *sf;
     CORE_ADDR addr;
     int mainline;
{
  struct coff_symfile_info *info = (struct coff_symfile_info *)sf->sym_private;
  bfd *abfd = sf->objfile->obfd;
  char *name = bfd_get_filename (abfd);
  int desc;
  register int val;
  int symtab_offset;
  int stringtab_offset;

/* WARNING WILL ROBINSON!  ACCESSING BFD-PRIVATE DATA HERE!  FIXME!  */
   desc = fileno ((FILE *)(abfd->iostream));    /* Raw file descriptor */
/* End of warning */

  /* Position to read the symbol table.  */
  val = lseek (desc, (long)symtab_offset, 0);
  if (val < 0)
    perror_with_name (name);

  init_misc_bunches ();
  make_cleanup (discard_misc_bunches, 0);

  /* Now that the executable file is positioned at symbol table,
     process it and define symbols accordingly.  */

  read_mips_symtab(sf->objfile, desc);

  /* Go over the misc symbol bunches and install them in vector.  */

  condense_misc_bunches (!mainline);
}
  
/* Exported procedure: Allocate zeroed memory */

char *
xzalloc(size)
{
        char           *p = xmalloc(size);

        memset(p, 0, size);
        return p;
}

/* Exported procedure: Builds a symtab from the PST partial one.
   Restores the environment in effect when PST was created, delegates
   most of the work to an ancillary procedure, and sorts
   and reorders the symtab list at the end */

static void
mipscoff_psymtab_to_symtab(pst)
        struct partial_symtab *pst;
{
        struct symtab  *ret;
        int             i;

        if (!pst)
                return;

        if (info_verbose) {
                printf_filtered("Reading in symbols for %s...", pst->filename);
                fflush(stdout);
        }
        /* Restore the header and list of pending typedefs */
        cur_hdr = CUR_HDR(pst);

        next_symbol_text_func = mips_next_symbol_text;

        psymtab_to_symtab_1(pst, pst->filename);

        /* Match with global symbols.  This only needs to be done once,
           after all of the symtabs and dependencies have been read in.   */
        scan_file_globals ();

        if (info_verbose)
                printf_filtered("done.\n");
}

/* Exported procedure: Is PC in the signal trampoline code */

int
in_sigtramp(pc, name)
        CORE_ADDR pc;
        char *name;
{
        if (sigtramp_address == 0)
                fixup_sigtramp();
        return (pc >= sigtramp_address && pc < sigtramp_end);
}
\f
/* File-level interface functions */

/* Read the symtab information from file FSYM into memory.  Also,
   return address just past end of our text segment in *END_OF_TEXT_SEGP.  */

static
read_the_mips_symtab(abfd, fsym, end_of_text_segp)
        bfd             *abfd;
        int             fsym;
        CORE_ADDR       *end_of_text_segp;
{
        int             stsize, st_hdrsize;
        unsigned        st_filptr;
        HDRR            st_hdr;
        /* Header for executable/object file we read symbols from */
        struct coff_exec filhdr;

        /* We get here with DESC pointing to the symtab header. But we need
         * other info from the initial headers */
        lseek(fsym, 0L, 0);
        myread(fsym, &filhdr, sizeof filhdr);

        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 0;

        lseek(fsym, st_filptr, L_SET);
        if (st_hdrsize > sizeof (st_hdr))       /* Profanity check */
                abort();
        if (read(fsym, &st_hdr, st_hdrsize) != st_hdrsize)
                goto readerr;

        /* 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(cur_hdr, &st_hdr, st_hdrsize);
        if (read(fsym, (char *) cur_hdr + st_hdrsize, stsize) != stsize)
                goto readerr;

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

        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. */

static
fixup_symtab( hdr, data, f_ptr)
        HDRR *hdr;
        char *data;
{
        int             f_idx, s_idx;
        FDR            *fh;
        SYMR           *sh;
        OPTR           *op;
        PDR            *pr;
        EXTR           *esh;

        /*
         * 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 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;
                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;
                        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(AUXU);
                /* 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;

                        /* 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: fix string */
        for (s_idx = 0; s_idx < hdr->iextMax; s_idx++) {
                esh = (EXTR*)(hdr->cbExtOffset) + s_idx;
                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 DESC. INCREMENTAL says
   whether we are adding to the general symtab or not. 
   FIXME:  INCREMENTAL is currently always zero, though it should not be. */

static
read_mips_symtab (objfile, desc)
        struct objfile *objfile;
        int desc;
{
        CORE_ADDR end_of_text_seg;

        read_the_mips_symtab(objfile->obfd, desc, &end_of_text_seg);

        parse_partial_symbols(end_of_text_seg, objfile);

#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
}
\f
/* Local utilities */

/* Map of FDR indexes to partial symtabs */

static struct pst_map {
        struct partial_symtab *pst;     /* the psymtab proper */
} * fdr_to_pst;


/* 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 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 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;
}

/* Check whether we already saw type T in file FH as undefined */

static
struct mips_pending *is_pending_type(fh, t)
        FDR *fh;
        struct type *t;
{
        int             f_idx = fh - (FDR *) cur_hdr->cbFdOffset;
        register struct mips_pending *p;

        for (p = pending_list[f_idx]; p; p = p->next)
                if (p->t == t)
                        break;
        return p;
}

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

static
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 */

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

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

/* The number of args to a procedure is not explicit in the symtab,
   this is the list of all those we know of.
   This makes parsing more reasonable and avoids extra passes */

static struct numarg {
        struct numarg   *next;          /* link */
        unsigned         adr;           /* procedure's start address */
        unsigned         num;           /* arg count */
} *numargs_list;

/* Record that the procedure at ADR takes NUM arguments. */

static
got_numargs(adr,num)
{
        struct numarg  *n = (struct numarg *) xmalloc(sizeof(struct numarg));

        n->adr = adr;
        n->num = num;
        n->next = numargs_list;
        numargs_list = n;
}

/* See if we know how many arguments the procedure at ADR takes */

static
lookup_numargs(adr)
{
        struct numarg  *n = numargs_list;

        while (n && n->adr != adr)
                n = n->next;
        return (n) ? n->num : -1;
}

/* Release storage when done with this file */

static void
free_numargs()
{
        struct numarg  *n = numargs_list, *m;

        while (n) {
                m = n->next;
                free(n);
                n = m;
        }
        numargs_list = 0;
}

\f
/* 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.
   Return count of SYMR's handled (normally one). */

static int
parse_symbol(sh, ax)
        SYMR *sh;
        AUXU *ax;
{
        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
           we mark it explicitly */
        int             pend = (sh->reserved == 1);
        enum address_class class;

        switch (sh->st) {

            case stNil:
                break;

            case stGlobal:      /* external symbol, goes into global block */
                class = LOC_STATIC;
                b = BLOCKVECTOR_BLOCK(BLOCKVECTOR(top_stack->cur_st),
                                      GLOBAL_BLOCK);
                s = new_symbol(sh->iss);
                SYMBOL_VALUE_ADDRESS(s) = (CORE_ADDR)sh->value;
                goto data;

            case stStatic:      /* static data, goes into current block. */
                class = LOC_STATIC;
                b = top_stack->cur_block;
                s = new_symbol(sh->iss);
                SYMBOL_VALUE_ADDRESS(s) = (CORE_ADDR)sh->value;
                goto data;

            case stLocal:       /* local variable, goes into current block */
                if (sh->sc == scRegister) {
                        class = LOC_REGISTER;
                        if (sh->value > 31)
                                sh->value += 6;
                } else
                        class = LOC_LOCAL;
                b = top_stack->cur_block;
                s = new_symbol(sh->iss);
                SYMBOL_VALUE(s) = sh->value;

data:           /* Common code for symbols describing data */
                SYMBOL_NAMESPACE(s) = VAR_NAMESPACE;
                SYMBOL_CLASS(s) = class;
                add_symbol(s, b);

                /* Type could be missing in a number of cases */
                if (sh->sc == scUndefined || sh->sc == scNil ||
                    sh->index == 0xfffff)
                        SYMBOL_TYPE(s) = builtin_type_int;      /* undefined? */
                else
                        SYMBOL_TYPE(s) = parse_type(ax + sh->index, sh, 0);
                /* Value of a data symbol is its memory address */
                break;

            case stParam:       /* arg to procedure, goes into current block */
                max_gdbinfo++;
                top_stack->numargs++;

                name = (char*)sh->iss;
                /* Special GNU C++ name.  */
                if (name[0] == CPLUS_MARKER && name[1] == 't' && name[2] == 0)
                    name = "this";
                s = new_symbol(name);

                SYMBOL_NAMESPACE(s) = VAR_NAMESPACE;
                if (sh->sc == scRegister) {
                        SYMBOL_CLASS(s) = LOC_REGPARM;
                        if (sh->value > 31)
                                sh->value += 6;
                } else
                        SYMBOL_CLASS(s) = LOC_ARG;
                SYMBOL_VALUE(s) = sh->value;
                SYMBOL_TYPE(s) = parse_type(ax + sh->index, sh, 0);
                add_symbol(s, top_stack->cur_block);
#if 0
                /* FIXME:  This has not been tested.  See dbxread.c */
                /* Add the type of this parameter to the function/procedure
                   type of this block. */
                add_param_to_type(&top_stack->cur_block->function->type,s);
#endif
                break;

            case stLabel:       /* label, goes into current block */
                s = new_symbol(sh->iss);
                SYMBOL_NAMESPACE(s) = VAR_NAMESPACE;    /* so that it can be used */
                SYMBOL_CLASS(s) = LOC_LABEL;            /* but not misused */
                SYMBOL_VALUE_ADDRESS(s) = (CORE_ADDR)sh->value;
                SYMBOL_TYPE(s) = builtin_type_int;
                add_symbol(s, top_stack->cur_block);
                break;

            case stProc:        /* Procedure, usually goes into global block */
            case stStaticProc:  /* Static procedure, goes into current block */
                s = new_symbol(sh->iss);
                SYMBOL_NAMESPACE(s) = VAR_NAMESPACE;
                SYMBOL_CLASS(s) = LOC_BLOCK;
                /* Type of the return value */
                if (sh->sc == scUndefined || sh->sc == scNil)
                        t = builtin_type_int;
                else
                        t = parse_type(ax + sh->index, sh, 0);
                b = top_stack->cur_block;
                if (sh->st == stProc) {
                    struct blockvector *bv = BLOCKVECTOR(top_stack->cur_st);
                    /* The next test should normally be true,
                       but provides a hook for nested functions
                       (which we don't want to make global). */
                    if (b == BLOCKVECTOR_BLOCK(bv, STATIC_BLOCK))
                        b = BLOCKVECTOR_BLOCK(bv, GLOBAL_BLOCK);
                }
                add_symbol(s, b);

                /* Make a type for the procedure itself */
#if 0
                /* FIXME:  This has not been tested yet!  See dbxread.c */
                /* Generate a template for the type of this function.  The 
                   types of the arguments will be added as we read the symbol 
                   table. */
                bcopy(SYMBOL_TYPE(s),lookup_function_type(t),sizeof(struct type));
#else
                SYMBOL_TYPE(s) = lookup_function_type (t);
#endif

                /* Create and enter a new lexical context */
                b = new_block(top_stack->maxsyms);
                SYMBOL_BLOCK_VALUE(s) = b;
                BLOCK_FUNCTION(b) = s;
                BLOCK_START(b) = BLOCK_END(b) = sh->value;
                BLOCK_SUPERBLOCK(b) = top_stack->cur_block;
                add_block(b, top_stack->cur_st);

                /* Not if we only have partial info */
                if (sh->sc == scUndefined || sh->sc == scNil)
                        break;

                push_parse_stack();
                top_stack->cur_block = b;
                top_stack->blocktype = sh->st;
                top_stack->cur_type = SYMBOL_TYPE(s);
                top_stack->cur_field = -1;
                top_stack->procadr = sh->value;
                top_stack->numargs = 0;

                sh->value = (long) SYMBOL_TYPE(s);
                break;


#ifndef btVoid  /* btVoid was added late. */
#define btVoid 26
#endif                          
/* These new symbol types have been recently added to SGI machines. */
#ifndef stStruct
#define stStruct 26
#endif
#ifndef stUnion
#define stUnion 27
#endif
#ifndef stEnum
#define stEnum 28
#endif
            case stStruct:
            case stUnion:
            case stEnum:

            case stBlock:       /* Either a lexical block, or some type */
                push_parse_stack();
                top_stack->blocktype = stBlock;
                if (sh->sc == scInfo) { /* structure/union/enum def */
                    int type_code =
                        sh->st == stStruct ? TYPE_CODE_STRUCT
                      : sh->st == stUnion ? TYPE_CODE_UNION
                      : sh->st == stEnum ? TYPE_CODE_ENUM
                      : TYPE_CODE_UNDEF;
                    int nfields = 0;
                    SYMR *tsym;
                    long max_value = 0;
                    struct field *f;

                    s = new_symbol(sh->iss);
                    SYMBOL_NAMESPACE(s) = STRUCT_NAMESPACE;
                    SYMBOL_CLASS(s) = LOC_TYPEDEF;
                    SYMBOL_VALUE(s) = 0;
                    add_symbol(s, top_stack->cur_block);
                    /* If this type was expected, use its partial definition */
                    if (pend)
                        t = is_pending_symbol(cur_fdr, sh)->t;
                    else
                        t = new_type(sh->iss);

                    /* First count the number of fields. */
                    for (tsym = sh+1; tsym->st != stEnd; tsym++)
                        if (tsym->st == stMember) {
                            if (nfields == 0 && type_code == TYPE_CODE_UNDEF)
                                /* If the type of the member is Void,
                                   assume the tag is an enumeration. */
                                if (tsym->index == indexNil
                                    || ax[tsym->index].ti.bt == btVoid)
                                    type_code = TYPE_CODE_ENUM;
                            nfields++;
                            if (tsym->value > max_value)
                                max_value = tsym->value;
                        }
                        else if (tsym->st == stBlock
                                 || tsym->st == stParsed) {
                            if (tsym->sc == scVariant) ; /*UNIMPLEMENTED*/
                            if (tsym->index != 0)
                                tsym = ((SYMR*)cur_fdr->isymBase)
                                    + tsym->index-1;
                        }
                    
                    
                    /* There is no guaranteed way to distinguish struct,
                       unions, and enums at this point.  This is a bug in the
                       original design (that has been fixed with the
                       recent addition of the stStruct, stUnion, and stEnum
                       symbol types.)  The way you can tell is if/when you
                       see a variable or field of that type:  In that case
                       the variable's type (in the AUX table) says if the
                       type is struct, union, or enum,
                       and points back to the stBlock here.
                       So you can patch the tag kind up later - but only
                       if there actually is a variable or field of that type.

                       So until we know for sure, we will guess at this point.
                       The heuristic is:
                       If the first member has index==indexNil or a void type,
                       assume we have an enumeration.
                       Otherwise, if all the members have offset 0,
                       assume we have a union.
                       Otherwise, assume we have a struct.

                       The heuristic could guess wrong in the case of
                       of an enumeration with no members or a union
                       with one (or zero) members, or when all except the
                       last field of a struct have width zero.
                       These are uncommon and/or illegal situations, and
                       in any case guessing wrong probably doesn't matter much.

                       But if we later do find out we were wrong,
                       we fixup the tag kind.  Members of an enumeration
                       must be handled differently from struct/union fields,
                       and that is harder to patch up, but luckily we
                       shouldn't need to.  (If there are any enumeration
                       members, we can tell for sure it's an enum here.) */

                    if (type_code == TYPE_CODE_UNDEF)
                        if (max_value == 0) type_code = TYPE_CODE_UNION;
                        else type_code = TYPE_CODE_STRUCT;
                    
                    TYPE_CODE(t) = type_code;
                    TYPE_NFIELDS(t) = nfields;
                    TYPE_FIELDS(t) = f = (struct field*)
                        obstack_alloc (symbol_obstack,
                                       nfields * sizeof (struct field));
                    
                    if (type_code == TYPE_CODE_ENUM) {
                        /* This is a non-empty enum. */
                        while (sh[1].st == stMember) {
                            struct symbol *enum_sym;
                            sh++;
                            f->bitpos = sh->value;
                            f->type = t;
                            f->name = (char*)sh->iss;
                            f->bitsize = 0;
                            
                            enum_sym = (struct symbol *)
                                obstack_alloc (symbol_obstack,
                                               sizeof (struct symbol));
                            memset (enum_sym, 0, sizeof (struct symbol));
                            SYMBOL_NAME (enum_sym) = f->name;
                            SYMBOL_CLASS (enum_sym) = LOC_CONST;
                            SYMBOL_TYPE (enum_sym) = t;
                            SYMBOL_NAMESPACE (enum_sym) = VAR_NAMESPACE;
                            SYMBOL_VALUE (enum_sym) = sh->value;
                            add_symbol(enum_sym, top_stack->cur_block);
                            
                            /* Skip the stMembers that we've handled. */
                            count++;
                            f++;
                        }
                    }
                    SYMBOL_TYPE(s) = t;
                    /* make this the current type */
                    top_stack->cur_type = t;
                    top_stack->cur_field = 0;
                    TYPE_LENGTH(t) = sh->value;
                    /* Mark that symbol has a type, and say which one */
                    sh->value = (long) t;
                } else {
                        /* beginnning of (code) block. Value of symbol
                           is the displacement from procedure start */
                        b = new_block(top_stack->maxsyms);
                        BLOCK_START(b) = sh->value + top_stack->procadr;
                        BLOCK_SUPERBLOCK(b) = top_stack->cur_block;
                        top_stack->cur_block = b;
                        add_block(b, top_stack->cur_st);
                }
                break;

            case stEnd:         /* end (of anything) */
                if (sh->sc == scInfo) {
                        /* Finished with type */
                        top_stack->cur_type = 0;
                } else if (sh->sc == scText &&
                           (top_stack->blocktype == stProc ||
                            top_stack->blocktype == stStaticProc)) {
                    /* Finished with procedure */
                    struct blockvector *bv = BLOCKVECTOR(top_stack->cur_st);
                    struct block *b;
                    int i;

                    BLOCK_END(top_stack->cur_block) += sh->value; /* size */
                    got_numargs(top_stack->procadr, top_stack->numargs);
                    /* Reallocate symbols, saving memory */
                    b = shrink_block(top_stack->cur_block, top_stack->cur_st);

                    /* f77 emits proc-level with address bounds==[0,0],
                       So look for such child blocks, and patch them.  */
                    for (i = 0; i < BLOCKVECTOR_NBLOCKS(bv); i++) {
                        struct block *b_bad = BLOCKVECTOR_BLOCK(bv,i);
                        if (BLOCK_SUPERBLOCK(b_bad) == b
                         && BLOCK_START(b_bad) == top_stack->procadr
                         && BLOCK_END(b_bad) == top_stack->procadr) {
                            BLOCK_START(b_bad) = BLOCK_START(b);
                            BLOCK_END(b_bad) = BLOCK_END(b);
                        }
                    }
                } else if (sh->sc == scText && top_stack->blocktype == stBlock) {
                        /* End of (code) block. The value of the symbol
                           is the displacement from the procedure`s start
                           address of the end of this block. */
                        BLOCK_END(top_stack->cur_block) = sh->value + top_stack->procadr;
                        (void) shrink_block(top_stack->cur_block, top_stack->cur_st);
                }
                pop_parse_stack();      /* restore previous lexical context */
                break;

            case stMember:      /* member of struct or union */
                f = &TYPE_FIELDS(top_stack->cur_type)[top_stack->cur_field++];
                f->name = (char*)sh->iss;
                f->bitpos = sh->value;
                f->bitsize = 0;
                f->type = parse_type(ax + sh->index, sh, &f->bitsize);
                break;

            case stTypedef:     /* type definition */
                s = new_symbol(sh->iss);
                SYMBOL_NAMESPACE(s) = VAR_NAMESPACE;
                SYMBOL_CLASS(s) = LOC_TYPEDEF;
                SYMBOL_BLOCK_VALUE(s) = top_stack->cur_block;
                add_symbol(s, top_stack->cur_block);                    
                SYMBOL_TYPE(s) = parse_type(ax + sh->index, sh, 0);
                sh->value = (long) SYMBOL_TYPE(s);
                break;

            case stFile:        /* file name */
                push_parse_stack();
                top_stack->blocktype = sh->st;
                break;

                /* I`ve never seen these for C */
            case stRegReloc:
                break;          /* register relocation */
            case stForward:
                break;          /* forwarding address */
            case stConstant:
                break;          /* constant */
            default:
                error("Unknown symbol type %x.", sh->st);
        }
        sh->st = stParsed;
        return count;
}

/* Parse the type information provided in the AX entries for
   the symbol SH. Return the bitfield size in BS, in case. */

static struct type *parse_type(ax, sh, bs)
        AUXU    *ax;
        SYMR    *sh;
        int     *bs;
{
        /* Null entries in this map are treated specially */
        static struct type **map_bt[] =
        {
                 &builtin_type_void,            /* btNil */
                 0,                             /* btAdr */
                 &builtin_type_char,            /* btChar */
                 &builtin_type_unsigned_char,   /* btUChar */
                 &builtin_type_short,           /* btShort */
                 &builtin_type_unsigned_short,  /* btUShort */
                 &builtin_type_int,             /* btInt */
                 &builtin_type_unsigned_int,    /* btUInt */
                 &builtin_type_long,            /* btLong */
                 &builtin_type_unsigned_long,   /* btULong */
                 &builtin_type_float,           /* btFloat */
                 &builtin_type_double,          /* btDouble */
                 0,                             /* btStruct */
                 0,                             /* btUnion */
                 0,                             /* btEnum */
                 0,                             /* btTypedef */
                 0,                             /* btRange */
                 0,                             /* btSet */
                 &builtin_type_complex,         /* btComplex */
                 &builtin_type_double_complex,  /* btDComplex */
                 0,                             /* btIndirect */
                 &builtin_type_fixed_dec,       /* btFixedDec */
                 &builtin_type_float_dec,       /* btFloatDec */
                 &builtin_type_string,          /* btString */
                 0,                             /* btBit */
                 0,                             /* btPicture */
                 &builtin_type_void,            /* btVoid */
        };

        TIR            *t;
        struct type    *tp = 0;
        char           *fmt;
        int             i;
        int type_code;

        /* Procedures start off by one */
        if (sh->st == stProc || sh->st == stStaticProc)
                ax++;

        /* Undefined ? Should not happen */
        if (ax->rndx.rfd == 0xfff) {
                return builtin_type_void;
        }

        /* Use aux as a type information record, map its basic type */
        t = &ax->ti;
        if (t->bt > (sizeof (map_bt)/sizeof (*map_bt))) {
                complain (&basic_type_complaint, t->bt);
                return builtin_type_int;
        }
        if (map_bt[t->bt]) {
                tp = *map_bt[t->bt];
                fmt = "%s";
        } else {
                tp = NULL;
                /* Cannot use builtin types -- build our own */
                switch (t->bt) {
                    case btAdr:
                        tp = lookup_pointer_type (builtin_type_void);
                        fmt = "%s";
                        break;
                    case btStruct:
                        type_code = TYPE_CODE_STRUCT;
                        fmt = "struct %s";
                        break;
                    case btUnion:
                        type_code = TYPE_CODE_UNION;
                        fmt = "union %s";
                        break;
                    case btEnum:
                        type_code = TYPE_CODE_ENUM;
                        fmt = "enum %s";
                        break;
                    case btRange:
                        type_code = TYPE_CODE_RANGE;
                        fmt = "%s";
                        break;
                    case btSet:
                        type_code = TYPE_CODE_SET;
                        fmt = "set %s";
                        break;
                    case btTypedef:
                    default:
                        complain (&basic_type_complaint, t->bt);
                        return builtin_type_int;
                }
        }

        /* Move on to next aux */
        ax++;
        if (t->continued) {
                /* This is the way it would work if the compiler worked */
                register TIR *t1 = t;
                while (t1->continued)
                        ax++;
        }

        if (t->fBitfield) {
                *bs = ax->width;
                ax++;
        }

        /* All these types really point to some (common) MIPS type
           definition, and only the type-qualifiers fully identify
           them.  We'll make the same effort at sharing. */
        if (t->bt == btIndirect ||
            t->bt == btStruct ||
            t->bt == btUnion ||
            t->bt == btEnum ||
            t->bt == btTypedef ||
            t->bt == btRange ||
            t->bt == btSet) {
                char            name[256], *pn;

                /* Try to cross reference this type */
                ax += cross_ref(ax, &tp, type_code, &pn);
                /* reading .o file ? */
                if (UNSAFE_DATA_ADDR(tp))
                    tp = make_type(type_code, 0, 0, 0);
                /* SOMEONE OUGHT TO FIX DBXREAD TO DROP "STRUCT" */
                sprintf(name, fmt, pn);

                /* Usually, TYPE_CODE(tp) is already type_code.  The main
                   exception is if we guessed wrong re struct/union/enum. */
                if (TYPE_CODE(tp) != type_code) {
                    complain (&bad_tag_guess_complaint, 0);
                    TYPE_CODE(tp) = type_code;
                }
                TYPE_NAME(tp) = obsavestring(pn, strlen(pn));
        }

        /* Deal with range types */
        if (t->bt == btRange) {
                struct field   *f;

                TYPE_NFIELDS (tp) = 2;
                TYPE_FIELDS (tp) =
                    (struct field *) obstack_alloc (symbol_obstack,
                                                    2 * sizeof (struct field));
                TYPE_FIELD_NAME (tp, 0) = "Low";
                TYPE_FIELD_BITPOS (tp, 0) = ax->dnLow;
                ax++;
                TYPE_FIELD_NAME (tp, 1) = "High";
                TYPE_FIELD_BITPOS (tp, 1) = ax->dnHigh;
                ax++;
        }

        /* Parse all the type qualifiers now. If there are more
           than 6 the game will continue in the next aux */

#define PARSE_TQ(tq) \
        if (t->tq != tqNil) ax += upgrade_type(&tp, t->tq, ax, sh);

again:  PARSE_TQ(tq0);
        PARSE_TQ(tq1);
        PARSE_TQ(tq2);
        PARSE_TQ(tq3);
        PARSE_TQ(tq4);
        PARSE_TQ(tq5);
#undef  PARSE_TQ

        if (t->continued) {
                t++;
                goto again;
        }
        return tp;
}

/* Make up a complex type from a basic one.  Type is passed by
   reference in TPP and side-effected as necessary. The type
   qualifier TQ says how to handle the aux symbols at AX for
   the symbol SX we are currently analyzing.
   Returns the number of aux symbols we parsed. */

static int
upgrade_type(tpp, tq, ax, sh)
        struct type   **tpp;
        AUXU           *ax;
        SYMR           *sh;
{
        int             off;
        struct type    *t;

        /* Used in array processing */
        int             rf, id;
        FDR            *fh;
        struct field   *f;
        SYMR            ss;
        int             lower, upper;

        switch (tq) {
        case tqPtr:
                t = lookup_pointer_type (*tpp);
                *tpp = t;
                return 0;

        case tqProc:
                t = lookup_function_type (*tpp);
                *tpp = t;
                return 0;

        case tqArray:
                off = 0;
                t = make_type(TYPE_CODE_ARRAY, 0, 0, 0);
                TYPE_TARGET_TYPE(t) = *tpp;

                /* Determine and record the domain type (type of index) */
                id = ax->rndx.index;
                rf = ax->rndx.rfd;
                if (rf == 0xfff) {
                        rf = (++ax)->isym;
                        off++;
                }
                fh = get_rfd(cur_fd, rf);

                /* Fields are kept in an array */
                /* FIXME - Memory leak! */
                if (TYPE_NFIELDS(t))
                    TYPE_FIELDS(t) = (struct field*)
                        xrealloc(TYPE_FIELDS(t),
                                 (TYPE_NFIELDS(t)+1) * sizeof(struct field));
                else
                    TYPE_FIELDS(t) = (struct field*)
                        xzalloc(sizeof(struct field));
                f = &(TYPE_FIELD(t,TYPE_NFIELDS(t)));
                TYPE_NFIELDS(t)++;
                memset(f, 0, sizeof(struct field));

                memset(&ss, 0, sizeof ss);
/* XXX */       f->type = parse_type(fh->iauxBase + id * sizeof(AUXU),
                                     &ss, &f->bitsize);

                if (off == 0) {
                /*
                 * This seems to be a pointer to the end of the Block defining
                 * the type.  Why it is here is magic for me, and I have no
                 * good use for it anyways.
                 */
                        /* This used to occur because cross_ref returned
                           the wrong result (ax pointed wrong).  FIXME,
                           delete this code in a while.  -- gnu@cygnus jul91 */
                        complain (&array_parse_complaint, 0);
                        off++;
                        id = (++ax)->rndx.index;
                        if ((rf = ax->rndx.rfd) == 0xfff)
                                rf = (++ax)->isym, off++;
                }
                lower = (++ax)->dnLow;
                upper = (++ax)->dnHigh;
                rf = (++ax)->width;     /* bit size of array element */

                /* Check whether supplied array element bit size matches
                   the known size of the element type.  If this complaint
                   ends up not happening, we can remove this code.  It's
                   here because we aren't sure we understand this *&%&$
                   symbol format.  */
                id = TYPE_LENGTH(TYPE_TARGET_TYPE(t)) << 3; /* bitsize */
                if (id == 0) {
                        /* Most likely an undefined type */
                        id = rf;
                        TYPE_LENGTH(TYPE_TARGET_TYPE(t)) = id >> 3;
                }
                if (id != rf)
                        complain (&array_bitsize_complaint, rf);

                TYPE_LENGTH(t) = (upper < 0) ? 0 :
                        (upper - lower + 1) * (rf >> 3);
                *tpp = t;
                return 4 + off;

        case tqVol:
                /* Volatile -- currently ignored */
                return 0;

        default:
                complain (&unknown_type_qual_complaint, tq);
                return 0;
        }
}


/* Parse a procedure descriptor record PR.  Note that the procedure
   is parsed _after_ the local symbols, now we just make up the
   extra information we need into a special symbol that we insert
   in the procedure's main block.  Note also that images that
   have been partially stripped (ld -x) have been deprived
   of local symbols, and we have to cope with them here.
   The procedure's code ends at BOUND */

static
parse_procedure(pr, bound)
        PDR *pr;
{
        struct symbol *s, *i;
        SYMR *sh = (SYMR*)pr->isym;
        struct block *b;
        struct mips_extra_func_info *e;
        char name[100];
        char *sh_name;

        /* Reuse the MIPS record */
        e = (struct mips_extra_func_info *) pr;
        e->numargs = lookup_numargs(pr->adr);

        /* Make up our special symbol */
        i = new_symbol(".gdbinfo.");
        SYMBOL_VALUE(i) = (int)e;
        SYMBOL_NAMESPACE(i) = LABEL_NAMESPACE;
        SYMBOL_CLASS(i) = LOC_CONST;
        SYMBOL_TYPE(i) = builtin_type_void;

        /* Make up a name for static procedures. Sigh. */
        if (sh == (SYMR*)-1) {
            sprintf(name,".static_procedure@%x",pr->adr);
            sh_name = savestring(name, strlen(name));
            s = NULL;
        }
        else {
            sh_name = (char*)sh->iss;
            s = mylookup_symbol(sh_name, top_stack->cur_block,
                                VAR_NAMESPACE, LOC_BLOCK);
        }
        if (s != 0) {
                b = SYMBOL_BLOCK_VALUE(s);
        } else {
                s = new_symbol(sh_name);
                SYMBOL_NAMESPACE(s) = VAR_NAMESPACE;
                SYMBOL_CLASS(s) = LOC_BLOCK;
                /* Donno its type, hope int is ok */
                SYMBOL_TYPE(s) = lookup_function_type (builtin_type_int);
                add_symbol(s, top_stack->cur_block);
                /* Wont have symbols for this one */
                b = new_block(2);
                SYMBOL_BLOCK_VALUE(s) = b;
                BLOCK_FUNCTION(b) = s;
                BLOCK_START(b) = pr->adr;
                BLOCK_END(b) = bound;
                BLOCK_SUPERBLOCK(b) = top_stack->cur_block;
                add_block(b, top_stack->cur_st);
        }
        e->isym = (long)s;
        add_symbol(i,b);
}

/* Parse the external symbol ES. Just call parse_symbol() after
   making sure we know where the aux are for it. For procedures,
   parsing of the PDRs has already provided all the needed
   information, we only parse them if SKIP_PROCEDURES is false,
   and only if this causes no symbol duplication.

   This routine clobbers top_stack->cur_block and ->cur_st. */

static
parse_external(es, skip_procedures)
        EXTR *es;
{
        AUXU *ax;

        if (es->ifd != ifdNil) {
                cur_fd = es->ifd;
                cur_fdr = (FDR*)(cur_hdr->cbFdOffset) + cur_fd;
                ax = (AUXU*)cur_fdr->iauxBase;
        } else {
                cur_fdr = (FDR*)(cur_hdr->cbFdOffset);
                ax = 0;
        }
        top_stack->cur_st = cur_stab;
        top_stack->cur_block = BLOCKVECTOR_BLOCK(BLOCKVECTOR(top_stack->cur_st),
                                                 GLOBAL_BLOCK);

        /* Reading .o files */
        if (es->asym.sc == scUndefined || es->asym.sc == scNil) {
                char *what;
                switch (es->asym.st) {
                case stStaticProc:
                case stProc:    what = "procedure"; n_undef_procs++;  break;
                case stGlobal:  what = "variable";  n_undef_vars++;   break;
                case stLabel:   what = "label";     n_undef_labels++; break;
                default :       what = "symbol";                      break;
                }
                n_undef_symbols++;
                if (info_verbose)
                        printf_filtered("Warning: %s `%s' is undefined (in %s)\n", what,
                                es->asym.iss, fdr_name(cur_fdr->rss));
                return;
        }

        switch (es->asym.st) {
        case stProc:
                /* If we have full symbols we do not need more */
                if (skip_procedures)
                        return;
                if (mylookup_symbol (es->asym.iss, top_stack->cur_block,
                                        VAR_NAMESPACE, LOC_BLOCK))
                        break;
                /* fall through */
        case stGlobal:
        case stLabel:
                /*
                 * Note that the case of a symbol with indexNil
                 * must be handled anyways by parse_symbol().
                 */
                parse_symbol(&es->asym, ax);
                break;
        default:
                break;
        }
}

/* Parse the line number info for file descriptor FH into
   GDB's linetable LT.  MIPS' encoding requires a little bit
   of magic to get things out.  Note also that MIPS' line
   numbers can go back and forth, apparently we can live
   with that and do not need to reorder our linetables */

static
parse_lines(fh, lt)
        FDR *fh;
        struct linetable *lt;
{
        unsigned char *base = (unsigned char*)fh->cbLineOffset;
        int i, j, k;
        int delta, count, lineno = 0;
        PDR *pr;

        if (base == 0)
                return;

        /* Scan by procedure descriptors */
        i = 0; j = 0, k = 0;
        for (pr = (PDR*)IPDFIRST(cur_hdr,fh); j < fh->cpd; j++, pr++) {
                int l, halt;

                /* No code for this one */
                if (pr->iline == ilineNil ||
                    pr->lnLow == -1 || pr->lnHigh == -1)
                        continue;
                /*
                 *      Aurgh! To know where to stop expanding we
                 *      must look-ahead.
                 */
                for (l = 1; l < (fh->cpd - j); l++)
                        if (pr[l].iline != -1)
                                break;
                if (l == (fh->cpd - j))
                        halt = fh->cline;
                else
                        halt = pr[l].iline;
                /*
                 * When procedures are moved around the linenumbers
                 * are attributed to the next procedure up
                 */
                if (pr->iline >= halt) continue;

                base = (unsigned char*)pr->cbLineOffset;
                l = pr->adr >> 2;       /* in words */
                halt += (pr->adr >> 2) - pr->iline;
                for (lineno = pr->lnLow; l < halt;) {
                        count = *base & 0x0f;
                        delta = *base++ >> 4;
                        if (delta >= 8)
                                delta -= 16;
                        if (delta == -8) {
                                delta = (base[0] << 8) | base[1];
                                if (delta >= 0x8000)
                                        delta -= 0x10000;
                                base += 2;
                        }
                        lineno += delta;/* first delta is 0 */
                        k = add_line(lt, lineno, l, k);
                        l += count + 1;
                }
        }
}

\f
/* Master parsing procedure for first-pass reading of file symbols
   into a partial_symtab.

   Parses the symtab described by the global symbolic header CUR_HDR.
   END_OF_TEXT_SEG gives the address just after the text segment for
   the symtab we are reading.  */

static
parse_partial_symbols(end_of_text_seg, objfile)
        int end_of_text_seg;
        struct objfile *objfile;
{
        int             f_idx, s_idx;
/*      int  stat_idx, h_max;*/
        HDRR            *hdr;
        /* Running pointers */
        FDR             *fh;
        RFDT            *rh;
        register EXTR   *esh;
        register SYMR   *sh;
        struct partial_symtab *pst;

  int past_first_source_file = 0;

  /* List of current psymtab's include files */
  char **psymtab_include_list;
  int includes_allocated;
  int includes_used;

  /* Index within current psymtab dependency list */
  struct partial_symtab **dependency_list;
  int dependencies_used, dependencies_allocated;

  includes_allocated = 30;
  includes_used = 0;
  psymtab_include_list = (char **) alloca (includes_allocated *
                                           sizeof (char *));
  next_symbol_text_func = mips_next_symbol_text;

  dependencies_allocated = 30;
  dependencies_used = 0;
  dependency_list =
    (struct partial_symtab **) alloca (dependencies_allocated *
                                       sizeof (struct partial_symtab *));

  last_source_file = 0;

        /*
         * Big plan: 
         *
         * Only parse the Local and External symbols, and the Relative FDR.
         * Fixup enough of the loader symtab to be able to use it.
         * Allocate space only for the file's portions we need to
         * look at. (XXX)
         */

        hdr = cur_hdr;
        max_gdbinfo = 0;
        max_glevel = MIN_GLEVEL;

        /* Allocate the map FDR -> PST.
           Minor hack: -O3 images might claim some global data belongs
           to FDR -1. We`ll go along with that */
        fdr_to_pst = (struct pst_map *)xzalloc((hdr->ifdMax+1) * sizeof *fdr_to_pst);
        fdr_to_pst++;
        {
                struct partial_symtab * pst = new_psymtab("", objfile);
                fdr_to_pst[-1].pst = pst;
                FDR_IDX(pst) = -1;
        }

        /* Pass 2 over external syms: fill in external symbols */
        for (s_idx = 0; s_idx < hdr->iextMax; s_idx++) {
                register struct partial_symbol *p;
                enum misc_function_type misc_type = mf_text;
                esh = (EXTR *) (hdr->cbExtOffset) + s_idx;

                if (esh->asym.sc == scUndefined || esh->asym.sc == scNil)
                        continue;

                switch (esh->asym.st) {
                case stProc:
                        break;
                case stGlobal:
                        misc_type = mf_data;
                        break;
                case stLabel:
                        break;
                default:
                        misc_type = mf_unknown;
                        complain (&unknown_ext_complaint, SYMBOL_NAME(p));
                }
                prim_record_misc_function ((char *)(esh->asym.iss),
                                           esh->asym.value,
                                           misc_type);
        }

        /* Pass 3 over files, over local syms: fill in static symbols */
        for (f_idx = 0; f_idx < hdr->ifdMax; f_idx++) {
            struct partial_symtab *save_pst;
            
            cur_fdr = fh = f_idx + (FDR *)(cur_hdr->cbFdOffset);

            if (fh->csym == 0) {
                fdr_to_pst[f_idx].pst = NULL;
                continue;
            }
            pst = start_psymtab (objfile, 0, (char*)fh->rss,
                                 fh->cpd ? fh->adr : 0,
                                 -1,
                                 global_psymbols.next,
                                 static_psymbols.next);
            save_pst = pst;
            /* Make everything point to everything. */
            FDR_IDX(pst) = f_idx;
            fdr_to_pst[f_idx].pst = pst;
            fh->ioptBase = (int)pst;
            
            CUR_HDR(pst) = cur_hdr;
            
            /* The way to turn this into a symtab is to call... */
            pst->read_symtab = mipscoff_psymtab_to_symtab;
            
            pst->texthigh = pst->textlow;
            
            pst->globals_offset = global_psymbols.next - global_psymbols.list;
            pst->statics_offset = static_psymbols.next - static_psymbols.list;
            
            pst->n_global_syms = 0;
            pst->n_static_syms = 0;
            
            /* The second symbol must be @stab.
               This symbol is emitted by mips-tfile to signal
               that the current object file uses encapsulated stabs
               instead of mips ecoff for local symbols.
               (It is the second symbol because the first symbol is
               the stFile used to signal the start of a file). */
            if (fh->csym >= 2
                && strcmp(((SYMR *)fh->isymBase)[1].iss, stabs_symbol) == 0) {
                for (cur_sdx = 2; cur_sdx < fh->csym; cur_sdx++) {
                    int type_code;
                    char *namestring;
                    sh = cur_sdx + (SYMR *) fh->isymBase;
                    type_code = MIPS_UNMARK_STAB(sh->index);
                    if (!MIPS_IS_STAB(sh)) {
                        if (sh->st == stProc || sh->st == stStaticProc) {
                            long procaddr = sh->value;
                            sh = (sh->index + (AUXU *)fh->iauxBase)->isym
                                + (SYMR *) fh->isymBase - 1;
                            if (sh->st == stEnd) {
                                long high = procaddr + sh->value;
                                if (high > pst->texthigh)
                                    pst->texthigh = high;
                            }
                        }
                        continue;
                    }
#define SET_NAMESTRING() namestring = (char*)sh->iss
#define CUR_SYMBOL_TYPE type_code
#define CUR_SYMBOL_VALUE sh->value
#define START_PSYMTAB(ofile,addr,fname,low,symoff,global_syms,static_syms)\
  pst = save_pst
#define END_PSYMTAB(pst,ilist,ninc,c_off,c_text,dep_list,n_deps) (void)0
#define addr 0          /* FIXME, should be offset of addresses */
#define HANDLE_RBRAC(val) \
  if ((val) > save_pst->texthigh) save_pst->texthigh = (val);
#include "partial-stab.h"
#undef addr
                }
            }
            else {
                for (cur_sdx = 0; cur_sdx < fh->csym; ) {
                    register struct partial_symbol *p;
                    char *name;
                    int class;
                    sh = cur_sdx + (SYMR *) fh->isymBase;
                    
                    if (MIPS_IS_STAB(sh)) {
                        cur_sdx++;
                        continue;
                    }

                    if (sh->sc == scUndefined || sh->sc == scNil ||
                        sh->index == 0xfffff) {
                        /* FIXME, premature? */
                        cur_sdx++;
                        continue;
                    }
                    
                    name = (char *)(sh->iss);
                    
                    switch (sh->st) {
                        long high;
                        long procaddr;
                      case stProc:              /* Asm labels apparently */
                      case stStaticProc:                /* Function */
                        ADD_PSYMBOL_TO_LIST(name, strlen(name),
                                            VAR_NAMESPACE, LOC_BLOCK,
                                            static_psymbols, sh->value);
                        /* Skip over procedure to next one. */
                        cur_sdx = (sh->index + (AUXU *)fh->iauxBase)->isym;
                        procaddr = sh->value;
                        
                        sh = cur_sdx + (SYMR *) fh->isymBase - 1;
                        if (sh->st != stEnd)
                            continue;
                        high = procaddr + sh->value;
                        if (high > pst->texthigh)
                            pst->texthigh = high;
                        continue;
                      case stStatic:                    /* Variable */
                        class = LOC_STATIC;
                        break;
                      case stTypedef:                   /* Typedef */
                        class = LOC_TYPEDEF;
                        break;
                      case stConstant:          /* Constant decl */
                        class = LOC_CONST;
                        break;
                      case stBlock:                     /* { }, str, un, enum*/
                        if (sh->sc == scInfo) {
                            ADD_PSYMBOL_TO_LIST(name, strlen(name),
                                                STRUCT_NAMESPACE, LOC_TYPEDEF,
                                                static_psymbols, sh->value);
                        }
                        /* Skip over the block */
                        cur_sdx = sh->index;
                        continue;
                      case stFile:                      /* File headers */
                      case stLabel:                     /* Labels */
                      case stEnd:                       /* Ends of files */
                        goto skip;
                      default:
                        complain (&unknown_sym_complaint, SYMBOL_NAME(p));
                        complain (&unknown_st_complaint, sh->st);
                        cur_sdx++;
                        continue;
                    }
                    /* Use this gdb symbol */
                    ADD_PSYMBOL_TO_LIST(name, strlen(name),
                                        VAR_NAMESPACE, class,
                                        static_psymbols, sh->value);
                  skip:
                    cur_sdx++;          /* Go to next file symbol */
                }
            }
            end_psymtab (save_pst, psymtab_include_list, includes_used,
                         -1, save_pst->texthigh,
                         dependency_list, dependencies_used,
                         global_psymbols.next, static_psymbols.next);
            if (entry_point < save_pst->texthigh
                && entry_point >= save_pst->textlow) {
                startup_file_start = save_pst->textlow;
                startup_file_end = save_pst->texthigh;
            }
        }

        /* Mark the last code address, and remember it for later */
        hdr->cbDnOffset = end_of_text_seg;

        free(&fdr_to_pst[-1]);
        fdr_to_pst = 0;
}


/* Do the initial analisys of the F_IDX-th file descriptor.
   Allocates a partial symtab for it, and builds the list
   of dependent files by recursion. LEV says at which level
   of recursion we are called (to pretty up debug traces) */

static struct partial_symtab *
parse_fdr(f_idx, lev, objfile)
        int f_idx;
        int lev;
        struct objfile *objfile;
{
        register FDR *fh;
        register struct partial_symtab *pst;
        int s_idx, s_id0;

        fh = (FDR *) (cur_hdr->cbFdOffset) + f_idx;

        /* Use this to indicate into which symtab this file was parsed */
        if (fh->ioptBase)
                return (struct partial_symtab *) fh->ioptBase;

        /* Debuggability level */
        if (compare_glevel(max_glevel, fh->glevel) < 0)
                max_glevel = fh->glevel;

        /* Make a new partial_symtab */
        pst = new_psymtab(fh->rss, objfile);
        if (fh->cpd == 0){
                pst->textlow = 0;
                pst->texthigh = 0;
        } else {
                pst->textlow = fh->adr;
                pst->texthigh = fh->cpd;        /* To be fixed later */
        }

        /* Make everything point to everything. */
        FDR_IDX(pst) = f_idx;
        fdr_to_pst[f_idx].pst = pst;
        fh->ioptBase = (int)pst;

        /* Analyze its dependencies */
        if (fh->crfd <= 1)
                return pst;

        s_id0 = 0;
        if (fh->cpd == 0) {  /* If there are no functions defined here ... */
                /* ...then presumably a .h file: drop reverse depends .h->.c */
                for (; s_id0 < fh->crfd; s_id0++) {
                        RFDT *rh = (RFDT *) (fh->rfdBase) + s_id0;
                        if (*rh == f_idx) {
                                s_id0++;        /* Skip self-dependency */
                                break;
                        }
                }
        }
        pst->number_of_dependencies = fh->crfd - s_id0;
        pst->dependencies = (struct partial_symtab **)
                obstack_alloc (psymbol_obstack,
                                 pst->number_of_dependencies *
                                   sizeof (struct partial_symtab *));
        for (s_idx = s_id0; s_idx < fh->crfd; s_idx++) {
                RFDT *rh = (RFDT *) (fh->rfdBase) + s_idx;

                pst->dependencies[s_idx-s_id0] = parse_fdr(*rh, lev+1, objfile);
        }

        return pst;
}

static char*
mips_next_symbol_text ()
{
    cur_sdx++;
    return (char*)((SYMR *)cur_fdr->isymBase)[cur_sdx].iss;
}

/* Ancillary function to psymtab_to_symtab().  Does all the work
   for turning the partial symtab PST into a symtab, recurring
   first on all dependent psymtabs.  The argument FILENAME is
   only passed so we can see in debug stack traces what file
   is being read. */

static void
psymtab_to_symtab_1(pst, filename)
     struct partial_symtab *pst;
     char *filename;
{
    int have_stabs;
    int             i, f_max;
    struct symtab  *st;
    FDR *fh;
    int maxlines;
    struct linetable *lines;

    if (pst->readin)
        return;
    pst->readin = 1;
    
    /* How many symbols will we need */
    /* FIXME, this does not count enum values. */
    f_max = pst->n_global_syms + pst->n_static_syms;
    if (FDR_IDX(pst) == -1) {
        fh = 0;
        maxlines = 0;
    } else {
        fh = (FDR *) (cur_hdr->cbFdOffset) + FDR_IDX(pst);
        f_max += fh->csym + fh->cpd;
        maxlines = 2 * fh->cline;
    }

    /* See comment in parse_partial_symbols about the @stabs sentinel. */
    have_stabs =
        fh && fh->csym >= 2
            && strcmp(((SYMR *)fh->isymBase)[1].iss, stabs_symbol) == 0;

    if (!have_stabs) {
        if (fh)
            st = new_symtab (pst->filename, 2 * f_max, maxlines,
                             pst->objfile);
        else
            st = new_symtab ("unknown", f_max, 0, pst->objfile);
        lines = LINETABLE(st);
        pending_list = (struct mips_pending **) cur_hdr->cbOptOffset;
        if (pending_list == 0) {
            pending_list = (struct mips_pending **)
                xzalloc(cur_hdr->ifdMax * sizeof(struct mips_pending *));
            cur_hdr->cbOptOffset = (int)pending_list;
        }
    }
    
    /* Read in all partial symbtabs on which this one is dependent.
       NOTE that we do have circular dependencies, sigh.  We solved
       that by setting pst->readin before this point.  */
    
    for (i = 0; i < pst->number_of_dependencies; i++)
        if (!pst->dependencies[i]->readin) {
            /* Inform about additional files to be read in.  */
            if (info_verbose)
                {
                    fputs_filtered (" ", stdout);
                    wrap_here ("");
                    fputs_filtered ("and ", stdout);
                    wrap_here ("");
                    printf_filtered ("%s...",
                                     pst->dependencies[i]->filename);
                    wrap_here ("");             /* Flush output */
                    fflush (stdout);
                }
            /* We only pass the filename for debug purposes */
            psymtab_to_symtab_1(pst->dependencies[i], 
                                pst->dependencies[i]->filename);
        }
    
    cur_fdr = fh;
    /* Now read the symbols for this symtab */
    
    if (!have_stabs) {
        cur_fd = FDR_IDX(pst);
        cur_stab = st;
        
        /* Get a new lexical context */
        
        push_parse_stack();
        top_stack->cur_st = cur_stab;
        top_stack->cur_block = BLOCKVECTOR_BLOCK(BLOCKVECTOR(cur_stab),
                                                 STATIC_BLOCK);
        BLOCK_START(top_stack->cur_block) = fh ? fh->adr : 0;
        BLOCK_END(top_stack->cur_block) = 0;
        top_stack->blocktype = stFile;
        top_stack->maxsyms = 2*f_max;
        top_stack->cur_type = 0;
        top_stack->procadr = 0;
        top_stack->numargs = 0;
    }
    
    /* Parse locals and procedures */
    if (fh) {
        SYMR *sh;
        PDR *pr;
        int f_idx = cur_fd;
        char *fh_name = (char*)fh->rss;
        
        /* Parse local symbols first */
        
        
        if (have_stabs) {
            if (fh->csym <= 2)
                return;
            for (cur_sdx = 2; cur_sdx < fh->csym; cur_sdx++) {
                register SYMR   *sh = cur_sdx + (SYMR *) fh->isymBase;
                char *name = (char*)sh->iss;
                CORE_ADDR valu = sh->value;
                if (MIPS_IS_STAB(sh)) {
                    int type_code = MIPS_UNMARK_STAB(sh->index);
                    process_one_symbol (type_code, 0, valu, name, /*FIXME*/ 0);
                }
                else if (sh->st == stLabel && sh->index != indexNil) {
                    /* Handle encoded stab line number. */
                    record_line (current_subfile, sh->index, valu);
                }
            }
            st = end_symtab (pst->texthigh, 0, 0, pst->objfile);
        }
        else {
            /* BOUND is the highest core address of this file's procedures */
            int bound =  cur_fd == cur_hdr->ifdMax - 1 ? cur_hdr->cbDnOffset
                : fh[1].adr;
            for (cur_sdx = 0; cur_sdx < fh->csym; ) {
                sh = (SYMR *) (fh->isymBase) + cur_sdx;
                cur_sdx += parse_symbol(sh, fh->iauxBase);
            }

            /* Procedures next, note we need to look-ahead to
               find out where the procedure's code ends */

            for (i = 0; i < fh->cpd-1; i++) {
                pr = (PDR *) (IPDFIRST(cur_hdr, fh)) + i;
                parse_procedure(pr, pr[1].adr); /* next proc up */
            }
            if (fh->cpd) {
                pr = (PDR *) (IPDFIRST(cur_hdr, fh)) + i;
                parse_procedure(pr, bound);     /* next file up */
            }
            /* Linenumbers. At the end, check if we can save memory */
            parse_lines(fh, lines);
            if (lines->nitems < fh->cline)
                lines = shrink_linetable(lines);
        }

    }
    if (!have_stabs) {
        LINETABLE(st) = lines;
    
        /* .. and our share of externals.
           XXX use the global list to speed up things here. how ? 
           FIXME, Maybe quit once we have found the right number of ext's? */
        /* parse_external clobbers top_stack->cur_block and ->cur_st here. */
        top_stack->blocktype = stFile;
        top_stack->maxsyms =
            cur_hdr->isymMax + cur_hdr->ipdMax + cur_hdr->iextMax;

        for (i = 0; i < cur_hdr->iextMax; i++) {
            register EXTR *esh = (EXTR *) (cur_hdr->cbExtOffset) + i;
            if (esh->ifd == cur_fd)
                parse_external(esh, 1);
        }
    
        /* If there are undefined, tell the user */
        if (n_undef_symbols) {
            printf_filtered("File %s contains %d unresolved references:",
                            st->filename, n_undef_symbols);
            printf_filtered("\n\t%4d variables\n\t%4d procedures\n\t%4d labels\n",
                            n_undef_vars, n_undef_procs, n_undef_labels);
            n_undef_symbols = n_undef_labels = n_undef_vars = n_undef_procs = 0;

        }
        pop_parse_stack();
    }
    
    /* Sort the symbol table now, we are done adding symbols to it.*/
    sort_symtab_syms(st);

    sort_blocks (st);
    
    /* Now link the psymtab and the symtab.  */
    pst->symtab = st;
}
\f
/* Ancillary parsing procedures. */

/* Lookup the type at relative index RN.  Return it in TPP
   if found and in any event come up with its name PNAME.
   Return value says how many aux symbols we ate */

static
cross_ref(rn, tpp, type_code, pname)
     RNDXR *rn;
     struct type **tpp;
     int type_code; /* Use to alloc new type if none is found. */
     char **pname;
{
        unsigned        rf;

        /* Escape index means 'the next one' */
        if (rn->rfd == 0xfff)
                rf = *(unsigned *) (rn + 1);
        else
                rf = rn->rfd;

        if (rf == -1) {
                /* Ooops */
                *pname = "<undefined>";
        } else {
                /*
                 * Find the relative file descriptor and the symbol in it 
                 */
                FDR            *fh = get_rfd(cur_fd, rf);
                SYMR           *sh;
                struct type    *t;

                /*
                 * If we have processed this symbol then we left a forwarding
                 * pointer to the corresponding GDB symbol.  If not, we`ll put
                 * it in a list of pending symbols, to be processed later when
                 * the file f will be.  In any event, we collect the name for
                 * the type here. Which is why we made a first pass at
                 * strings. 
                 */
                sh = (SYMR *) (fh->isymBase) + rn->index;

                /* Careful, we might be looking at .o files */
                *pname = (UNSAFE_DATA_ADDR(sh->iss)) ? "<undefined>" :
                        (char *) sh->iss;

                /* Have we parsed it ? */
                if ((!UNSAFE_DATA_ADDR(sh->value)) && (sh->st == stParsed)) {
                        t = (struct type *) sh->value;
                        *tpp = t;
                } else {
                    /* Avoid duplicates */
                    struct mips_pending *p = is_pending_symbol(fh, sh);
                    if (p)
                        *tpp = p->t;
                    else {
                        *tpp = make_type(type_code, 0, 0, 0);
                        add_pending(fh, sh, *tpp);
                    }
                }
        }

        /* We used one auxent normally, two if we got a "next one" rf. */
        return (rn->rfd == 0xfff? 2: 1);
}


/* Quick&dirty lookup procedure, to avoid the MI ones that require
   keeping the symtab sorted */

static struct symbol *
mylookup_symbol (name, block, namespace, class)
     char *name;
     register struct block *block;
     enum namespace namespace;
     enum address_class class;
{
        register int    bot, top, inc;
        register struct symbol *sym;

        bot = 0;
        top = BLOCK_NSYMS(block);
        inc = name[0];
        while (bot < top) {
                sym = BLOCK_SYM(block, bot);
                if (SYMBOL_NAME(sym)[0] == inc
                    && SYMBOL_NAMESPACE(sym) == namespace
                    && SYMBOL_CLASS(sym) == class
                    && !strcmp(SYMBOL_NAME(sym), name))
                        return sym;
                bot++;
        }
        if (block = BLOCK_SUPERBLOCK (block))
                return mylookup_symbol (name, block, namespace, class);
        return 0;
}


/* Add a new symbol S to a block B.
   Infrequently, we will need to reallocate the block to make it bigger.
   We only detect this case when adding to top_stack->cur_block, since
   that's the only time we know how big the block is.  FIXME.  */

static void
add_symbol(s,b)
        struct symbol *s;
        struct block *b;
{
        int nsyms = BLOCK_NSYMS(b)++;
        struct block *origb;
        struct parse_stack *stackp;

        if (b == top_stack->cur_block &&
            nsyms >= top_stack->maxsyms) {
                complain (&block_overflow_complaint, s->name);
                /* In this case shrink_block is actually grow_block, since
                   BLOCK_NSYMS(b) is larger than its current size.  */
                origb = b;
                b = shrink_block (top_stack->cur_block, top_stack->cur_st);

                /* Now run through the stack replacing pointers to the
                   original block.  shrink_block has already done this
                   for the blockvector and BLOCK_FUNCTION.  */
                for (stackp = top_stack; stackp; stackp = stackp->next) {
                        if (stackp->cur_block == origb) {
                                stackp->cur_block = b;
                                stackp->maxsyms = BLOCK_NSYMS (b);
                        }
                }
        }
        BLOCK_SYM(b,nsyms) = s;
}

/* Add a new block B to a symtab S */

static void
add_block(b,s)
        struct block *b;
        struct symtab *s;
{
        struct blockvector *bv = BLOCKVECTOR(s);

        bv = (struct blockvector *)xrealloc(bv, sizeof(struct blockvector) +
                                            BLOCKVECTOR_NBLOCKS(bv) * sizeof(bv->block));
        if (bv != BLOCKVECTOR(s))
                BLOCKVECTOR(s) = bv;

        BLOCKVECTOR_BLOCK(bv, BLOCKVECTOR_NBLOCKS(bv)++) = b;
}

/* Add a new linenumber entry (LINENO,ADR) to a linevector LT.
   MIPS' linenumber encoding might need more than one byte
   to describe it, LAST is used to detect these continuation lines */

static int
add_line(lt, lineno, adr, last)
        struct linetable *lt;
        int lineno;
        CORE_ADDR adr;
        int last;
{
        if (last == 0)
                last = -2;      /* make sure we record first line */

        if (last == lineno)     /* skip continuation lines */
                return lineno;

        lt->item[lt->nitems].line = lineno;
        lt->item[lt->nitems++].pc = adr << 2;
        return lineno;
}


\f
/* Comparison functions, used when sorting things */

/*  Symtabs must be ordered viz the code segments they cover */

static int
compare_symtabs( s1, s2)
        struct symtab **s1, **s2;
{
        /* "most specific" first */

        register struct block *b1, *b2;
        b1 = BLOCKVECTOR_BLOCK(BLOCKVECTOR(*s1),GLOBAL_BLOCK);
        b2 = BLOCKVECTOR_BLOCK(BLOCKVECTOR(*s2),GLOBAL_BLOCK);
        if (BLOCK_END(b1) == BLOCK_END(b2))
                return BLOCK_START(b1) - BLOCK_START(b2);
        return BLOCK_END(b1) - BLOCK_END(b2);
}


/*  Partial Symtabs, same */

static int
compare_psymtabs( s1, s2)
        struct partial_symtab **s1, **s2;
{
        /* Perf twist: put the ones with no code at the end */

        register int a = (*s1)->textlow;
        register int b = (*s2)->textlow;
        if (a == 0)
                return b;
        if (b == 0)
                return -a;
        return a - b;
}


/* Blocks with a smaller low bound should come first */

static int compare_blocks(b1,b2)
        struct block **b1, **b2;
{
        register int addr_diff;

        addr_diff = (BLOCK_START((*b1))) - (BLOCK_START((*b2)));
        if (addr_diff == 0)
                return (BLOCK_END((*b1))) - (BLOCK_END((*b2)));
        return addr_diff;
}

\f
/* Sorting and reordering procedures */

/* Sort the blocks of a symtab S.
   Reorder the blocks in the blockvector by code-address,
   as required by some MI search routines */

static void
sort_blocks(s)
        struct symtab *s;
{
        struct blockvector *bv = BLOCKVECTOR(s);

        if (BLOCKVECTOR_NBLOCKS(bv) <= 2) {
                /* Cosmetic */
                if (BLOCK_END(BLOCKVECTOR_BLOCK(bv,GLOBAL_BLOCK)) == 0)
                        BLOCK_START(BLOCKVECTOR_BLOCK(bv,GLOBAL_BLOCK)) = 0;
                if (BLOCK_END(BLOCKVECTOR_BLOCK(bv,STATIC_BLOCK)) == 0)
                        BLOCK_START(BLOCKVECTOR_BLOCK(bv,STATIC_BLOCK)) = 0;
                return;
        }
        /*
         * This is very unfortunate: normally all functions are compiled in
         * the order they are found, but if the file is compiled -O3 things
         * are very different.  It would be nice to find a reliable test
         * to detect -O3 images in advance.
         */
        if (BLOCKVECTOR_NBLOCKS(bv) > 3)
                qsort(&BLOCKVECTOR_BLOCK(bv,FIRST_LOCAL_BLOCK),
                      BLOCKVECTOR_NBLOCKS(bv) - FIRST_LOCAL_BLOCK,
                      sizeof(struct block *),
                      compare_blocks);

        {
                register CORE_ADDR high = 0;
                register int    i, j = BLOCKVECTOR_NBLOCKS(bv);

                for (i = FIRST_LOCAL_BLOCK; i < j; i++)
                        if (high < BLOCK_END(BLOCKVECTOR_BLOCK(bv,i)))
                                high = BLOCK_END(BLOCKVECTOR_BLOCK(bv,i));
                BLOCK_END(BLOCKVECTOR_BLOCK(bv,GLOBAL_BLOCK)) = high;
        }

        BLOCK_START(BLOCKVECTOR_BLOCK(bv,GLOBAL_BLOCK)) =
                BLOCK_START(BLOCKVECTOR_BLOCK(bv,FIRST_LOCAL_BLOCK));

        BLOCK_START(BLOCKVECTOR_BLOCK(bv,STATIC_BLOCK)) = 
                BLOCK_START(BLOCKVECTOR_BLOCK(bv,GLOBAL_BLOCK));
        BLOCK_END  (BLOCKVECTOR_BLOCK(bv,STATIC_BLOCK)) =
                BLOCK_END  (BLOCKVECTOR_BLOCK(bv,GLOBAL_BLOCK));
}

\f
/* Constructor/restructor/destructor procedures */

/* Allocate a new symtab for NAME.  Needs an estimate of how many symbols
   MAXSYMS and linenumbers MAXLINES we'll put in it */

static
struct symtab *
new_symtab(name, maxsyms, maxlines, objfile)
        char *name;
{
        struct symtab *s = allocate_symtab (name, objfile);

        LINETABLE(s) = new_linetable(maxlines);

        /* All symtabs must have at least two blocks */
        BLOCKVECTOR(s) = new_bvect(2);
        BLOCKVECTOR_BLOCK(BLOCKVECTOR(s), GLOBAL_BLOCK) = new_block(maxsyms);
        BLOCKVECTOR_BLOCK(BLOCKVECTOR(s), STATIC_BLOCK) = new_block(maxsyms);
        BLOCK_SUPERBLOCK( BLOCKVECTOR_BLOCK(BLOCKVECTOR(s),STATIC_BLOCK)) =
                BLOCKVECTOR_BLOCK(BLOCKVECTOR(s), GLOBAL_BLOCK);

        s->free_code = free_linetable;

        /* Link the new symtab into the list of such.  */
        s->next = symtab_list;
        symtab_list = s;

        return s;
}

/* Allocate a new partial_symtab NAME */

static struct partial_symtab *
new_psymtab(name, objfile)
        char *name;
        struct objfile *objfile;
{
        struct partial_symtab *pst;

        pst = (struct partial_symtab *)
              obstack_alloc (psymbol_obstack, sizeof (*pst));
        memset (pst, 0, sizeof (*pst));

        if (name == (char*)-1)          /* FIXME -- why not null here? */
                pst->filename = "<no name>";
        else
                pst->filename = name;

        /* Chain it to its object file */
        pst->objfile = objfile;
        pst->objfile_chain = objfile->psymtabs;
        objfile->psymtabs = pst;
        
        pst->next = partial_symtab_list;
        partial_symtab_list = pst;

        /* Keep a backpointer to the file's symbols */
        pst->read_symtab_private = (char *) obstack_alloc (psymbol_obstack,
                                                  sizeof (struct symloc));
        CUR_HDR(pst) = cur_hdr;

        /* The way to turn this into a symtab is to call... */
        pst->read_symtab = mipscoff_psymtab_to_symtab;

        return pst;
}


/* Allocate a linetable array of the given SIZE */

static struct linetable *
new_linetable(size)
{
        struct linetable *l;

        size = size * sizeof(l->item) + sizeof(struct linetable);
        l = (struct linetable *)xmalloc(size);
        l->nitems = 0;
        return l;
}

/* Oops, too big. Shrink it.  This was important with the 2.4 linetables,
   I am not so sure about the 3.4 ones */

static struct linetable *
shrink_linetable(lt)
        struct linetable * lt;
{
        struct linetable *l = new_linetable(lt->nitems);

        memcpy(l, lt, lt->nitems * sizeof(l->item) + sizeof(struct linetable));
        free (lt);
        return l;
}

/* Allocate and zero a new blockvector of NBLOCKS blocks. */

static
struct blockvector *
new_bvect(nblocks)
{
        struct blockvector *bv;
        int size;

        size = sizeof(struct blockvector) + nblocks * sizeof(struct block*);
        bv = (struct blockvector *) xzalloc(size);

        BLOCKVECTOR_NBLOCKS(bv) = nblocks;

        return bv;
}

/* Allocate and zero a new block of MAXSYMS symbols */

static
struct block *
new_block(maxsyms)
{
        int size = sizeof(struct block) + (maxsyms-1) * sizeof(struct symbol *);
        struct block *b = (struct block *)xzalloc(size);

        return b;
}

/* Ooops, too big. Shrink block B in symtab S to its minimal size.
   Shrink_block can also be used by add_symbol to grow a block.  */

static struct block *
shrink_block(b, s)
        struct block *b;
        struct symtab *s;
{
        struct block *new;
        struct blockvector *bv = BLOCKVECTOR(s);
        int i;

        /* Just reallocate it and fix references to the old one */

        new = (struct block *) xrealloc ((char *)b, sizeof(struct block) +
                (BLOCK_NSYMS(b)-1) * sizeof(struct symbol *));

        /* Should chase pointers to old one.  Fortunately, that`s just
           the block`s function and inferior blocks */
        if (BLOCK_FUNCTION(new) && SYMBOL_BLOCK_VALUE(BLOCK_FUNCTION(new)) == b)
                SYMBOL_BLOCK_VALUE(BLOCK_FUNCTION(new)) = new;
        for (i = 0; i < BLOCKVECTOR_NBLOCKS(bv); i++)
                if (BLOCKVECTOR_BLOCK(bv,i) == b)
                        BLOCKVECTOR_BLOCK(bv,i) = new;
                else if (BLOCK_SUPERBLOCK(BLOCKVECTOR_BLOCK(bv,i)) == b)
                        BLOCK_SUPERBLOCK(BLOCKVECTOR_BLOCK(bv,i)) = new;
        return new;
}

/* Create a new symbol with printname NAME */

static
struct symbol *
new_symbol(name)
        char *name;
{
        struct symbol *s = (struct symbol *) 
                obstack_alloc (symbol_obstack, sizeof (struct symbol));

        memset (s, 0, sizeof (*s));
        SYMBOL_NAME(s) = name;
        return s;
}

/* Create a new type with printname NAME */

static
struct type *
new_type(name)
        char *name;
{
        struct type *t = (struct type *)
                obstack_alloc (symbol_obstack, sizeof (struct type));

        memset (t, 0, sizeof (*t));
        TYPE_VPTR_FIELDNO (t) = -1;
        TYPE_NAME(t) = name;
        TYPE_CPLUS_SPECIFIC(t) = &cplus_struct_default;
        return t;
}

/* Create and initialize a new type with printname NAME.
   CODE and LENGTH are the initial info we put in,
   UNS says whether the type is unsigned or not.  */

static
struct type *
make_type(code, length, uns, name)
     enum type_code code;
     int length, uns;
     char *name;
{
    register struct type *type;
    
    /* FIXME, I don't think this ever gets freed.  */
    type = (struct type *) xzalloc(sizeof(struct type));
    TYPE_CODE(type) = code;
    TYPE_LENGTH(type) = length;
    TYPE_FLAGS(type) = uns ? TYPE_FLAG_UNSIGNED : 0;
    TYPE_NAME(type) = name;
    TYPE_VPTR_FIELDNO (type) = -1;
    
    if (code != TYPE_CODE_METHOD && code != TYPE_CODE_FUNC)
        TYPE_CPLUS_SPECIFIC(type) = &cplus_struct_default;
    return type;
}
\f
/* Things used for calling functions in the inferior.
   These functions are exported to our companion
   mips-tdep.c file and are here because they play
   with the symbol-table explicitly. */

/* Sigtramp: make sure we have all the necessary information
   about the signal trampoline code. Since the official code
   from MIPS does not do so, we make up that information ourselves.
   If they fix the library (unlikely) this code will neutralize itself. */

static
fixup_sigtramp()
{
        struct symbol  *s;
        struct symtab  *st;
        struct block   *b, *b0;

        sigtramp_address = -1;

        /* We know it is sold as sigvec */
        s = lookup_symbol("sigvec", 0, VAR_NAMESPACE, 0, NULL);

        /* Most programs do not play with signals */
        if (s == 0)
                return;

        b0 = SYMBOL_BLOCK_VALUE(s);

        /* A label of sigvec, to be more precise */
        s = lookup_symbol("sigtramp", b0, VAR_NAMESPACE, 0, NULL);

        /* But maybe this program uses its own version of sigvec */
        if (s == 0)
                return;

        sigtramp_address = SYMBOL_VALUE(s);
        sigtramp_end = sigtramp_address + 0x88; /* black magic */

        /* Did we or MIPSco fix the library ? */
        if (SYMBOL_CLASS(s) == LOC_BLOCK)
                return;

        /* But what symtab does it live in ? */
        st = find_pc_symtab(SYMBOL_VALUE(s));

        /*
         * Ok, there goes the fix: turn it into a procedure, with all the
         * needed info.  Note we make it a nested procedure of sigvec,
         * which is the way the (assembly) code is actually written.
         */
        SYMBOL_NAMESPACE(s) = VAR_NAMESPACE;
        SYMBOL_CLASS(s) = LOC_BLOCK;
        SYMBOL_TYPE(s) = make_type(TYPE_CODE_FUNC, 4, 0, 0);
        TYPE_TARGET_TYPE(SYMBOL_TYPE(s)) = builtin_type_void;

        /* Need a block to allocate .gdbinfo. in */
        b = new_block(1);
        SYMBOL_BLOCK_VALUE(s) = b;
        BLOCK_START(b) = sigtramp_address;
        BLOCK_END(b) = sigtramp_end;
        BLOCK_FUNCTION(b) = s;
        BLOCK_SUPERBLOCK(b) = BLOCK_SUPERBLOCK(b0);
        add_block(b, st);
        sort_blocks(st);

        /* Make a .gdbinfo. for it */
        {
                struct mips_extra_func_info *e =
                        (struct mips_extra_func_info *)
                        xzalloc(sizeof(struct mips_extra_func_info));

                e->numargs = 0; /* the kernel thinks otherwise */
                /* align_longword(sigcontext + SIGFRAME) */
                e->framesize = 0x150;
                e->framereg = SP_REGNUM;
                e->pcreg = 31;
                e->regmask = -2;
                e->regoffset = -(41 * sizeof(int));
                e->fregmask = -1;
                e->fregoffset = -(37 * sizeof(int));
                e->isym = (long)s;

                s = new_symbol(".gdbinfo.");
                SYMBOL_VALUE(s) = (int) e;
                SYMBOL_NAMESPACE(s) = LABEL_NAMESPACE;
                SYMBOL_CLASS(s) = LOC_CONST;
                SYMBOL_TYPE(s) = builtin_type_void;
        }

        BLOCK_SYM(b,BLOCK_NSYMS(b)++) = s;
}
\f
/* Initialization */

static struct sym_fns ecoff_sym_fns = {"ecoff", 5,
                mipscoff_new_init, mipscoff_symfile_init,
                mipscoff_symfile_read};

_initialize_mipsread ()
{
        add_symtab_fns (&ecoff_sym_fns);

        /* Missing basic types */
        builtin_type_string = make_type(TYPE_CODE_PASCAL_ARRAY,
                                        1, 0, "string");
        builtin_type_complex = make_type(TYPE_CODE_FLT,
                                         2 * sizeof(float), 0, "complex");
        builtin_type_double_complex = make_type(TYPE_CODE_FLT,
                                    2 * sizeof(double), 0, "double_complex");
        builtin_type_fixed_dec = make_type(TYPE_CODE_INT, sizeof(int),
                                           0, "fixed_decimal");
        builtin_type_float_dec = make_type(TYPE_CODE_FLT, sizeof(double),
                                           0, "floating_decimal");
}