diff options
| -rw-r--r-- | bfd/ChangeLog | 16 | ||||
| -rw-r--r-- | bfd/ecofflink.c | 195 |
2 files changed, 169 insertions, 42 deletions
diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 1eb35bd..caf4d04 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,19 @@ +2002-12-16 Nathan Tallent <eraxxon@alumni.rice.edu> + + * ecofflink.c: Fix the reading of the debugging information + of Tru64/Alpha binaries that are produced by recent Compaq + compilers. + (mk_fdrtab): Fix error in creating the FDR (file descriptor) + table. + (lookup_line): Because of the strange information sometimes + generated by Compaq's recent compilers, change how the FDR + table is searched so that PDRs (procedure descriptors) are + correctly found. Note that this change is really more of a hack; + however, I have included extensive documentation as to why + this is the best solution short of an extensive rewrite or + another hack. + (fdrtab_lookup): Add comments to explain the algorithm. + 2002-12-12 Alexandre Oliva <aoliva@redhat.com> * elf-m10300.c (elf32_mn10300_link_hash_newfunc): Reorder diff --git a/bfd/ecofflink.c b/bfd/ecofflink.c index 2ff5d1b..b74f18a 100644 --- a/bfd/ecofflink.c +++ b/bfd/ecofflink.c @@ -3,21 +3,21 @@ 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" @@ -1836,16 +1836,15 @@ mk_fdrtab (abfd, debug_info, debug_swap, line_info) 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) @@ -1868,7 +1867,7 @@ mk_fdrtab (abfd, debug_info, debug_swap, line_info) 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) @@ -1877,23 +1876,37 @@ mk_fdrtab (abfd, debug_info, debug_swap, line_info) 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; @@ -1937,14 +1950,22 @@ fdrtab_lookup (line_info, offset) 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; @@ -1967,6 +1988,7 @@ lookup_line (abfd, debug_info, debug_swap, line_info) 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 @@ -1977,10 +1999,80 @@ lookup_line (abfd, debug_info, debug_swap, line_info) 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 @@ -2006,7 +2098,7 @@ lookup_line (abfd, debug_info, debug_swap, line_info) 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; @@ -2068,14 +2160,29 @@ lookup_line (abfd, debug_info, debug_swap, line_info) 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; @@ -2098,7 +2205,10 @@ lookup_line (abfd, debug_info, debug_swap, line_info) 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; @@ -2106,21 +2216,22 @@ lookup_line (abfd, debug_info, debug_swap, line_info) } } - 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); @@ -2130,7 +2241,7 @@ lookup_line (abfd, debug_info, debug_swap, line_info) 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; |