toolchain/binutils/2.15.91.0.2/700-binutils-20040817-linkonce.patch

   1 From http://sources.redhat.com/ml/binutils/2004-08/msg00190.html
   2
   3 Date: Tue, 17 Aug 2004 12:04:29 +0200
   4 From: Jakub Jelinek <jakub at redhat dot com>
   5 To: binutils at sources dot redhat dot com
   6 Subject: [PATCH] Fix `defined in discarded section' errors when building ia64 gcc
   7 Message-ID: <20040817100429.GL30497@sunsite.ms.mff.cuni.cz>
   8 Reply-To: Jakub Jelinek <jakub at redhat dot com>
   9 References: <20040817090201.GK30497@sunsite.ms.mff.cuni.cz>
  10 In-Reply-To: <20040817090201 dot GK30497 at sunsite dot ms dot mff dot cuni dot cz>
  11
  12 On Tue, Aug 17, 2004 at 11:02:01AM +0200, Jakub Jelinek wrote:
  13 > Current gcc 3.4.x (at least gcc-3_4-rhl-branch) doesn't build with CVS
  14 > binutils (nor 2.15.91.0.2).
  15 > The problem is that libstdc++.so linking fails with:
  16 > `.gnu.linkonce.t._ZNSdD2Ev' referenced in section `.gnu.linkonce.ia64unw._ZNSdD2Ev' of .libs/sstream-inst.o: defined in discarded section `.gnu.linkonce.t._ZNSdD2Ev' of .libs/sstream-inst.o
  17 > The problem is that both io-inst.s and sstream-inst.s have
  18 > .gnu.linkonce.t._ZNSdD2Ev definition, but because io-inst.cc
  19 > also instantiates some templates sstream-inst.cc doesn't instantiate,
  20 > the inliner can do a better job in io-inst.cc.
  21 > The result is that _ZNSdD2Ev in io-inst.cc is a leaf routine, while
  22 > it is not in sstream-inst.cc (in assembly,
  23 > _ZNSdD2Ev in io-inst.s starts with .prologue and no .save directives,
  24 > while _ZNSdD2Ev] in sstream-inst.s has .prologue 12, 35 and some
  25 > .save directives.
  26 > IA-64 ABI allows leaf routines to have no unwind section at all,
  27 > which means .gnu.linkonce.ia64unw._ZNSdD2Ev is not created in
  28 > io-inst.o at all and as .gnu.linkonce.t._ZNSdD2Ev comes first
  29 > and wins, .gnu.linkonce.ia64unw._ZNSdD2Ev in sstream.o suddenly
  30 > references a discarded section.
  31 >
  32 > Not sure what should be done here, but certainly the compiler
  33 > isn't at fault here, it is a binutils problem.
  34 > One fix could be to create empty .gnu.linkonce.ia64unw.* section
  35 > in assembler, another special case ia64 unwind sections in the linker.
  36
  37 Here is a patch for the first possibility.
  38 It certainly makes libstdc++.so to link and even the unwind info looks
  39 good on brief skimming.
  40
  41 2004-08-17  Jakub Jelinek  <jakub@redhat.com>
  42
  43         * config/tc-ia64.c (start_unwind_section): Add linkonce_empty
  44         argument, don't do anything if current section is not
  45         .gnu.linkonce.t.* and linkonce_empty is set.
  46         (generate_unwind_image, dot_endp): Adjust callers, call
  47         start_unwind_section (*, 1) if nothing will be put into the
  48         section.
  49
  50 --- binutils/gas/config/tc-ia64.c.jj    2004-07-30 11:42:24.000000000 +0200
  51 +++ binutils/gas/config/tc-ia64.c       2004-08-17 13:45:04.288173205 +0200
  52 @@ -1,5 +1,6 @@
  53  /* tc-ia64.c -- Assembler for the HP/Intel IA-64 architecture.
  54 -   Copyright 1998, 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
  55 +   Copyright 1998, 1999, 2000, 2001, 2002, 2003, 2004
  56 +   Free Software Foundation, Inc.
  57     Contributed by David Mosberger-Tang <davidm@hpl.hp.com>
  58
  59     This file is part of GAS, the GNU Assembler.
  60 @@ -3297,7 +3298,7 @@ static char *special_linkonce_name[] =
  61    };
  62
  63  static void
  64 -start_unwind_section (const segT text_seg, int sec_index)
  65 +start_unwind_section (const segT text_seg, int sec_index, int linkonce_empty)
  66  {
  67    /*
  68      Use a slightly ugly scheme to derive the unwind section names from
  69 @@ -3359,6 +3360,8 @@ start_unwind_section (const segT text_se
  70        prefix = special_linkonce_name [sec_index - SPECIAL_SECTION_UNWIND];
  71        suffix += sizeof (".gnu.linkonce.t.") - 1;
  72      }
  73 +  else if (linkonce_empty)
  74 +    return;
  75
  76    prefix_len = strlen (prefix);
  77    suffix_len = strlen (suffix);
  78 @@ -3444,7 +3447,7 @@ generate_unwind_image (const segT text_s
  79        expressionS exp;
  80        bfd_reloc_code_real_type reloc;
  81
  82 -      start_unwind_section (text_seg, SPECIAL_SECTION_UNWIND_INFO);
  83 +      start_unwind_section (text_seg, SPECIAL_SECTION_UNWIND_INFO, 0);
  84
  85        /* Make sure the section has 4 byte alignment for ILP32 and
  86          8 byte alignment for LP64.  */
  87 @@ -3485,6 +3488,8 @@ generate_unwind_image (const segT text_s
  88           unwind.personality_routine = 0;
  89         }
  90      }
  91 +  else
  92 +    start_unwind_section (text_seg, SPECIAL_SECTION_UNWIND_INFO, 1);
  93
  94    free_saved_prologue_counts ();
  95    unwind.list = unwind.tail = unwind.current_entry = NULL;
  96 @@ -4164,7 +4169,7 @@ dot_endp (dummy)
  97        subseg_set (md.last_text_seg, 0);
  98        unwind.proc_end = expr_build_dot ();
  99
 100 -      start_unwind_section (saved_seg, SPECIAL_SECTION_UNWIND);
 101 +      start_unwind_section (saved_seg, SPECIAL_SECTION_UNWIND, 0);
 102
 103        /* Make sure that section has 4 byte alignment for ILP32 and
 104           8 byte alignment for LP64.  */
 105 @@ -4204,6 +4209,9 @@ dot_endp (dummy)
 106                             bytes_per_address);
 107
 108      }
 109 +  else
 110 +    start_unwind_section (saved_seg, SPECIAL_SECTION_UNWIND, 1);
 111 +
 112    subseg_set (saved_seg, saved_subseg);
 113
 114    /* Parse names of main and alternate entry points and set symbol sizes.  */
 115
 116
 117         Jakub
 118