Free Software Foundation, Inc.
Written by Ian Lance Taylor, Cygnus Support, <ian@cygnus.com>.
-This file is part of BFD, the Binary File Descriptor library.
+ This file is part of BFD, the Binary File Descriptor library.
-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 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.
+ 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+ 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#include "bfd.h"
#include "sysdep.h"
fdr_start = debug_info->fdr;
fdr_end = fdr_start + debug_info->symbolic_header.ifdMax;
- /* First, let's see how long the table needs to be: */
+ /* First, let's see how long the table needs to be. */
for (len = 0, fdr_ptr = fdr_start; fdr_ptr < fdr_end; fdr_ptr++)
{
- if (fdr_ptr->cpd == 0) /* skip FDRs that have no PDRs */
+ if (fdr_ptr->cpd == 0) /* Skip FDRs that have no PDRs. */
continue;
++len;
}
- /* Now, create and fill in the table: */
-
+ /* Now, create and fill in the table. */
amt = (bfd_size_type) len * sizeof (struct ecoff_fdrtab_entry);
line_info->fdrtab = (struct ecoff_fdrtab_entry*) bfd_zalloc (abfd, amt);
if (line_info->fdrtab == NULL)
SYMR sym;
sym_ptr = ((char *) debug_info->external_sym
- + (fdr_ptr->isymBase + 1)*debug_swap->external_sym_size);
+ + (fdr_ptr->isymBase + 1) * debug_swap->external_sym_size);
(*debug_swap->swap_sym_in) (abfd, sym_ptr, &sym);
if (strcmp (debug_info->ss + fdr_ptr->issBase + sym.iss,
STABS_SYMBOL) == 0)
if (!stabs)
{
- bfd_size_type external_pdr_size;
- char *pdr_ptr;
- PDR pdr;
-
- external_pdr_size = debug_swap->external_pdr_size;
-
- pdr_ptr = ((char *) debug_info->external_pdr
- + fdr_ptr->ipdFirst * external_pdr_size);
- (*debug_swap->swap_pdr_in) (abfd, (PTR) pdr_ptr, &pdr);
+ /* eraxxon: There are at least two problems with this computation:
+ 1) PDRs do *not* contain offsets but full vma's; and typically the
+ address of the first PDR is the address of the FDR, which will
+ make (most) of the results of the original computation 0!
+ 2) Once in a wacky while, the Compaq compiler generated PDR
+ addresses do not equal the FDR vma, but they (the PDR address)
+ are still vma's and not offsets. Cf. comments in
+ 'lookup_line'. */
+#if 0
+ bfd_size_type external_pdr_size;
+ char *pdr_ptr;
+ PDR pdr;
+
+ external_pdr_size = debug_swap->external_pdr_size;
+
+ pdr_ptr = ((char *) debug_info->external_pdr
+ + fdr_ptr->ipdFirst * external_pdr_size);
+ (*debug_swap->swap_pdr_in) (abfd, (PTR) pdr_ptr, &pdr);
/* The address of the first PDR is the offset of that
procedure relative to the beginning of file FDR. */
- tab->base_addr = fdr_ptr->adr - pdr.adr;
+ tab->base_addr = fdr_ptr->adr - pdr.adr;
+#else
+ /* The address of the first PDR is the offset of that
+ procedure relative to the beginning of file FDR. */
+ tab->base_addr = fdr_ptr->adr;
+#endif
}
else
{
/* XXX I don't know about stabs, so this is a guess
- (davidm@cs.arizona.edu): */
+ (davidm@cs.arizona.edu). */
tab->base_addr = fdr_ptr->adr;
}
tab->fdr = fdr_ptr;
else
low = mid + 1;
}
+
+ /* eraxxon: at this point 'offset' is either lower than the lowest entry or
+ higher than the highest entry. In the former case high = low = mid = 0;
+ we want to return -1. In the latter case, low = high and mid = low - 1;
+ we want to return the index of the highest entry. Only in former case
+ will the following 'catch-all' test be true. */
++mid;
- /* last entry is catch-all for all higher addresses: */
+ /* Last entry is catch-all for all higher addresses. */
if (offset < tab[mid].base_addr)
return -1;
find_min:
+ /* eraxxon: There may be multiple FDRs in the table with the
+ same base_addr; make sure that we are at the first one. */
while (mid > 0 && tab[mid - 1].base_addr == tab[mid].base_addr)
--mid;
FDR *fdr_ptr;
int i;
+ /* eraxxon: note that 'offset' is the full vma, not a section offset. */
offset = line_info->cache.start;
/* Build FDR table (sorted by object file's base-address) if we
tab = line_info->fdrtab;
- /* find first FDR for address OFFSET */
+ /* Find first FDR for address OFFSET. */
i = fdrtab_lookup (line_info, offset);
if (i < 0)
return FALSE; /* no FDR, no fun... */
+
+ /* eraxxon: 'fdrtab_lookup' doesn't give what we want, at least for Compaq's
+ C++ compiler 6.2. Consider three FDRs with starting addresses of x, y,
+ and z, respectively, such that x < y < z. Assume further that
+ y < 'offset' < z. It is possble at times that the PDR for 'offset' is
+ associated with FDR x and *not* with FDR y. Erg!!
+
+ From a binary dump of my C++ test case 'moo' using Compaq's coffobjanl
+ (output format has been edited for our purposes):
+
+ FDR [2]: (main.C): First instruction: 0x12000207c <x>
+ PDR [5] for File [2]: LoopTest__Xv <0x1200020a0> (a)
+ PDR [7] for File [2]: foo__Xv <0x120002168>
+ FDR [1]: (-1): First instruction: 0x1200020e8 <y>
+ PDR [3] for File [1]: <0x120001ad0> (b)
+ FDR [6]: (-1): First instruction: 0x1200026f0 <z>
+
+ (a) In the case of PDR5, the vma is such that the first few instructions
+ of the procedure can be found. But since the size of this procedure is
+ 160b, the vma will soon cross into the 'address space' of FDR1 and no
+ debugging info will be found. How repugnant!
+
+ (b) It is also possible for a PDR to have a *lower* vma than its associated
+ FDR; see FDR1 and PDR3. Gross!
+
+ Since the FDRs that are causing so much havok (in this case) 1) do not
+ describe actual files (fdr.rss == -1), and 2) contain only compiler
+ genarated routines, I thought a simple fix would be to exclude them from
+ the FDR table in 'mk_fdrtab'. But, besides not knowing for certain
+ whether this would be correct, it creates an additional problem. If we
+ happen to ask for source file info on a compiler generated (procedure)
+ symbol -- which is still in the symbol table -- the result can be
+ information from a real procedure! This is because compiler generated
+ procedures with vma's higher than the last FDR in the fdr table will be
+ associated with a PDR from this FDR, specifically the PDR with the
+ highest vma. This wasn't a problem before, because each procedure had a
+ PDR. (Yes, this problem could be eliminated if we kept the size of the
+ last PDR around, but things are already getting ugly).
+
+ Probably, a better solution would be to have a sorted PDR table. Each
+ PDR would have a pointer to its FDR so file information could still be
+ obtained. A FDR table could still be constructed if necessary -- since
+ it only contains pointers, not much extra memory would be used -- but
+ the PDR table would be searched to locate debugging info.
+
+ There is still at least one remaining issue. Sometimes a FDR can have a
+ bogus name, but contain PDRs that should belong to another FDR with a
+ real name. E.g:
+
+ FDR [3]: 0000000120001b50 (/home/.../Array.H~alt~deccxx_5E5A62AD)
+ PDR [a] for File [3]: 0000000120001b50
+ PDR [b] for File [3]: 0000000120001cf0
+ PDR [c] for File [3]: 0000000120001dc8
+ PDR [d] for File [3]: 0000000120001e40
+ PDR [e] for File [3]: 0000000120001eb8
+ PDR [f] for File [3]: 0000000120001f4c
+ FDR [4]: 0000000120001b50 (/home/.../Array.H)
+
+ Here, FDR4 has the correct name, but should (seemingly) contain PDRa-f.
+ The symbol table for PDR4 does contain symbols for PDRa-f, but so does
+ the symbol table for FDR3. However the former is different; perhaps this
+ can be detected easily. (I'm not sure at this point.) This problem only
+ seems to be associated with files with templates. I am assuming the idea
+ is that there is a 'fake' FDR (with PDRs) for each differently typed set
+ of templates that must be generated. Currently, FDR4 is completely
+ excluded from the FDR table in 'mk_fdrtab' because it contains no PDRs.
+
+ Since I don't have time to prepare a real fix for this right now, be
+ prepared for 'A Horrible Hack' to force the inspection of all non-stabs
+ FDRs. It's coming... */
fdr_ptr = tab[i].fdr;
/* Check whether this file has stabs debugging information. In a
char *pdr_ptr;
char *best_pdr = NULL;
FDR *best_fdr;
- bfd_vma best_dist = ~(bfd_vma) 0;
+ bfd_signed_vma best_dist = -1;
PDR pdr;
unsigned char *line_ptr;
unsigned char *line_end;
considerably, which is undesirable. */
external_pdr_size = debug_swap->external_pdr_size;
- /* Make offset relative to object file's start-address: */
+#if 0 /* eraxxon: PDR addresses (pdr.adr) are not relative to FDRs!
+ Leave 'offset' alone. */
+ /* Make offset relative to object file's start-address. */
offset -= tab[i].base_addr;
+#endif
+ /* eraxxon: The Horrible Hack: Because of the problems above, set 'i'
+ to 0 so we look through all FDRs.
+
+ Because FDR's without any symbols are assumed to be non-stabs,
+ searching through all FDRs may cause the following code to try to
+ read stabs FDRs as ECOFF ones. However, I don't think this will
+ harm anything. */
+ i = 0;
+
/* Search FDR list starting at tab[i] for the PDR that best matches
OFFSET. Normally, the FDR list is only one entry long. */
best_fdr = NULL;
do
{
- bfd_vma dist, min_dist = 0;
+ /* eraxxon: 'dist' and 'min_dist' can be negative now
+ because we iterate over every FDR rather than just ones
+ with a base address less than or equal to 'offset'. */
+ bfd_signed_vma dist = -1, min_dist = -1;
char *pdr_hold;
char *pdr_end;
if (offset >= (pdr.adr - 0x10 * pdr.prof))
{
dist = offset - (pdr.adr - 0x10 * pdr.prof);
- if (!pdr_hold || dist < min_dist)
+
+ /* eraxxon: 'dist' can be negative now. Note that
+ 'min_dist' can be negative if 'pdr_hold' below is NULL. */
+ if (!pdr_hold || (dist >= 0 && dist < min_dist))
{
min_dist = dist;
pdr_hold = pdr_ptr;
}
}
- if (!best_pdr || min_dist < best_dist)
+ if (!best_pdr || (min_dist >= 0 && min_dist < best_dist))
{
- best_dist = min_dist;
+ best_dist = (bfd_vma) min_dist;
best_fdr = fdr_ptr;
best_pdr = pdr_hold;
}
- /* continue looping until base_addr of next entry is different: */
+ /* Continue looping until base_addr of next entry is different. */
}
- while (++i < line_info->fdrtab_len
- && tab[i].base_addr == tab[i - 1].base_addr);
+ /* eraxxon: We want to iterate over all FDRs.
+ See previous comment about 'fdrtab_lookup'. */
+ while (++i < line_info->fdrtab_len);
if (!best_fdr || !best_pdr)
- return FALSE; /* shouldn't happen... */
+ return FALSE; /* Shouldn't happen... */
- /* phew, finally we got something that we can hold onto: */
+ /* Phew, finally we got something that we can hold onto. */
fdr_ptr = best_fdr;
pdr_ptr = best_pdr;
(*debug_swap->swap_pdr_in) (abfd, (PTR) pdr_ptr, &pdr);
number entries. */
line_end = debug_info->line + fdr_ptr->cbLineOffset + fdr_ptr->cbLine;
- /* Make offset relative to procedure entry: */
+ /* Make offset relative to procedure entry. */
offset -= pdr.adr - 0x10 * pdr.prof;
lineno = pdr.lnLow;
line_ptr = debug_info->line + fdr_ptr->cbLineOffset + pdr.cbLineOffset;
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