From: Ken Raeburn Date: Wed, 28 Sep 1994 19:20:11 +0000 (+0000) Subject: (fix_new_exp): Handle O_add by creating an expression-valued symbol, and X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=4acf8c78e659833be8be047ba2f8561386a11d4b;p=deliverable%2Fbinutils-gdb.git (fix_new_exp): Handle O_add by creating an expression-valued symbol, and calling fix_new_exp recursively. (adjust_reloc_syms): If a fixup's symbol value is a sum of an undefined symbol and a constant, fold the constant into the fixup, and refer to the undefined symbol directly. Then process the fixup again from scratch. (write_object_file): Before calling adjust_reloc_syms, make a pass through the symbol list trying to resolve values. (print_fixup): New routine, for debugging. (write_relocs): Call bfd_install_relocation. Deleted various hacks for working around problems with bfd_perform_relocation. --- diff --git a/gas/write.c b/gas/write.c index 8004ef73ac..6c109a3c3e 100644 --- a/gas/write.c +++ b/gas/write.c @@ -232,6 +232,19 @@ fix_new_exp (frag, where, size, exp, pcrel, r_type) case O_absent: break; + case O_add: + /* This comes up when _GLOBAL_OFFSET_TABLE_+(.-L0) is read, if + the difference expression cannot immediately be reduced. */ + { + extern symbolS *make_expr_symbol (); + symbolS *stmp = make_expr_symbol (exp); + exp->X_op = O_symbol; + exp->X_op_symbol = 0; + exp->X_add_symbol = stmp; + exp->X_add_number = 0; + return fix_new_exp (frag, where, size, exp, pcrel, r_type); + } + case O_uminus: sub = exp->X_add_symbol; off = exp->X_add_number; @@ -573,7 +586,11 @@ adjust_reloc_syms (abfd, sec, xxx) else if (fixp->fx_addsy) { symbolS *sym = fixp->fx_addsy; - asection *symsec = sym->bsym->section; + asection *symsec; + + reduce_fixup: + + symsec = sym->bsym->section; /* If it's one of these sections, assume the symbol is definitely going to be output. The code in @@ -617,6 +634,27 @@ adjust_reloc_syms (abfd, sec, xxx) } #endif + /* For PIC support: We may get expressions like + "_GLOBAL_OFFSET_TABLE_+(.-L5)" where "." and "L5" may not + necessarily have had a fixed difference initially. But now + it should be a known constant, so we can reduce it. Since + we can't easily handle a symbol value that looks like + someUndefinedSymbol+const, though, we convert the fixup to + access the undefined symbol directly, and discard the + intermediate symbol. */ + if (S_GET_SEGMENT (sym) == expr_section + && sym->sy_value.X_op == O_add + && (resolve_symbol_value (sym->sy_value.X_add_symbol), + S_GET_SEGMENT (sym->sy_value.X_add_symbol) == undefined_section) + && (resolve_symbol_value (sym->sy_value.X_op_symbol), + S_GET_SEGMENT (sym->sy_value.X_op_symbol) == absolute_section)) + { + fixp->fx_offset += S_GET_VALUE (sym->sy_value.X_op_symbol); + fixp->fx_offset += sym->sy_value.X_add_number; + fixp->fx_addsy = sym = sym->sy_value.X_add_symbol; + goto reduce_fixup; + } + /* If the section symbol isn't going to be output, the relocs at least should still work. If not, figure out what to do when we run into that case. */ @@ -676,7 +714,6 @@ write_relocs (abfd, sec, xxx) for (fixp = seginfo->fix_root; fixp != (fixS *) NULL; fixp = fixp->fx_next) { arelent *reloc; - char *data; bfd_reloc_status_type s; if (fixp->fx_done) @@ -690,24 +727,14 @@ write_relocs (abfd, sec, xxx) n--; continue; } - data = fixp->fx_frag->fr_literal + fixp->fx_where; if (fixp->fx_where + fixp->fx_size > fixp->fx_frag->fr_fix + fixp->fx_frag->fr_offset) abort (); - if (reloc->howto->partial_inplace == false - && reloc->howto->pcrel_offset == true - && reloc->howto->pc_relative == true) - { - /* bfd_perform_relocation screws this up */ - reloc->addend += reloc->address; - } - /* Pass bogus address so that when bfd_perform_relocation adds - `reloc->address' back in, it'll come up with `data', which is where - we want it to operate. We can't just do it by fudging reloc->address, - since that might be used in the calculations(?). */ - s = bfd_perform_relocation (stdoutput, reloc, data - reloc->address, - sec, stdoutput, &err); + s = bfd_install_relocation (stdoutput, reloc, + fixp->fx_frag->fr_literal, + fixp->fx_frag->fr_address, + sec, &err); switch (s) { case bfd_reloc_ok: @@ -716,7 +743,8 @@ write_relocs (abfd, sec, xxx) as_bad_where (fixp->fx_file, fixp->fx_line, "relocation overflow"); break; default: - as_fatal ("bad return from bfd_perform_relocation"); + as_fatal ("%s:%u: bad return from bfd_perform_relocation", + fixp->fx_file, fixp->fx_line); } relocs[i++] = reloc; } @@ -759,8 +787,13 @@ write_relocs (abfd, sec, xxx) { case bfd_reloc_ok: break; + case bfd_reloc_overflow: + as_bad_where (fixp->fx_file, fixp->fx_line, + "relocation overflow"); + break; default: - as_fatal ("bad return from bfd_perform_relocation"); + as_fatal ("%s:%u: bad return from bfd_perform_relocation", + fixp->fx_file, fixp->fx_line); } } } @@ -843,7 +876,7 @@ write_contents (abfd, sec, xxx) { bfd_perror (stdoutput->filename); as_perror ("FATAL: Can't write %s", stdoutput->filename); - exit (42); + exit (EXIT_FAILURE); } offset += f->fr_fix; } @@ -866,7 +899,7 @@ write_contents (abfd, sec, xxx) { bfd_perror (stdoutput->filename); as_perror ("FATAL: Can't write %s", stdoutput->filename); - exit (42); + exit (EXIT_FAILURE); } offset += fill_size; } @@ -1464,6 +1497,17 @@ write_object_file () #endif /* VMS */ #else /* BFD_ASSEMBLER */ + /* Resolve symbol values. This needs to be done before processing + the relocations. */ + if (symbol_rootP) + { + symbolS *symp; + + for (symp = symbol_rootP; symp; symp = symbol_next (symp)) + if (!symp->sy_resolved) + resolve_symbol_value (symp); + } + bfd_map_over_sections (stdoutput, adjust_reloc_syms, (char *)0); /* Set up symbol table, and write it out. */ @@ -1475,6 +1519,9 @@ write_object_file () { int punt = 0; + /* Do it again, because adjust_reloc_syms might introduce + more symbols. They'll probably only be section symbols, + but they'll still need to have the values computed. */ if (! symp->sy_resolved) { if (symp->sy_value.X_op == O_constant) @@ -2299,4 +2346,35 @@ number_to_chars_littleendian (buf, val, n) } } +/* for debugging */ +extern int indent_level; + +void +print_fixup (fixp) + fixS *fixp; +{ + indent_level = 1; + fprintf (stderr, "fix"); + if (fixp->fx_pcrel) + fprintf (stderr, " pcrel"); + if (fixp->fx_pcrel_adjust) + fprintf (stderr, " pcrel_adjust=%d", fixp->fx_pcrel_adjust); + if (fixp->fx_im_disp) + { +#ifdef TC_NS32K + fprintf (stderr, " im_disp=%d", fixp->fx_im_disp); +#else + fprintf (stderr, " im_disp"); +#endif + } + if (fixp->fx_tcbit) + fprintf (stderr, " tcbit"); + if (fixp->fx_done) + fprintf (stderr, " done"); + fprintf (stderr, "\n %s:%d", fixp->fx_file, fixp->fx_line); + fprintf (stderr, "\n size=%d frag=%lx where=%ld addnumber=%lx", + fixp->fx_size, (long) fixp->fx_frag, fixp->fx_where, + (long) fixp->fx_addnumber); +} + /* end of write.c */