libgcc/mkmap-symver.awk

   1 # Generate an ELF symbol version map a-la Solaris and GNU ld.
   2 #       Copyright (C) 2007-2020 Free Software Foundation, Inc.
   3 #       Contributed by Richard Henderson <rth@cygnus.com>
   4 #
   5 # This file is part of GCC.
   6 #
   7 # GCC is free software; you can redistribute it and/or modify it under
   8 # the terms of the GNU General Public License as published by the Free
   9 # Software Foundation; either version 3, or (at your option) any later
  10 # version.
  11 #
  12 # GCC is distributed in the hope that it will be useful, but WITHOUT
  13 # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  14 # or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
  15 # License for more details.
  16 #
  17 # You should have received a copy of the GNU General Public License
  18 # along with GCC; see the file COPYING3.  If not see
  19 # <http://www.gnu.org/licenses/>.
  20
  21 BEGIN {
  22   state = "nm";
  23   sawsymbol = 0;
  24   if (leading_underscore)
  25     prefix = "_";
  26   else
  27     prefix = "";
  28 }
  29
  30 # Remove comment and blank lines.
  31 /^ *#/ || /^ *$/ {
  32   next;
  33 }
  34
  35 # We begin with nm input.  Collect the set of symbols that are present
  36 # so that we cannot emit them into the final version script -- Solaris
  37 # complains at us if we do.
  38
  39 state == "nm" && /^%%/ {
  40   state = "ver";
  41   next;
  42 }
  43
  44 state == "nm" && ($1 == "U" || $2 == "U") {
  45   next;
  46 }
  47
  48 state == "nm" && NF == 3 {
  49   split ($3, s, "@")
  50   if (skip_underscore && substr(s[1], 1, 1) == "_")
  51       symname = substr(s[1], 2);
  52   else
  53       symname = s[1];
  54   def[symname] = 1;
  55   sawsymbol = 1;
  56   next;
  57 }
  58
  59 state == "nm" {
  60   next;
  61 }
  62
  63 # Now we process a simplified variant of the Solaris symbol version
  64 # script.  We have one symbol per line, no semicolons, simple markers
  65 # for beginning and ending each section, and %inherit markers for
  66 # describing version inheritance.  A symbol may appear in more than
  67 # one symbol version, and the last seen takes effect.
  68 # The magic version name '%exclude' causes all the symbols given that
  69 # version to be dropped from the output (unless a later version overrides).
  70
  71 NF == 3 && $1 == "%inherit" {
  72   inherit[$2] = $3;
  73   next;
  74 }
  75
  76 NF == 2 && $2 == "{" {
  77   if ($1 != "%exclude")
  78     libs[$1] = 1;
  79   thislib = $1;
  80   next;
  81 }
  82
  83 $1 == "}" {
  84   thislib = "";
  85   next;
  86 }
  87
  88 {
  89   sym = prefix $1;
  90   symbols[sym] = 1
  91   if (thislib != "%exclude")
  92     ver[sym, thislib] = 1;
  93   else {
  94     for (l in libs)
  95       ver[sym, l] = 0;
  96   }
  97   next;
  98 }
  99
 100 END {
 101   if (!sawsymbol)
 102     {
 103       print "No symbols seen -- broken or mis-installed nm?" | "cat 1>&2";
 104       exit 1;
 105     }
 106   for (l in libs)
 107     output(l);
 108 }
 109
 110 function output(lib) {
 111   if (done[lib])
 112     return;
 113   done[lib] = 1;
 114   if (inherit[lib])
 115     output(inherit[lib]);
 116
 117   empty=1
 118   for (sym in symbols)
 119     if ((ver[sym, lib] != 0) && (sym in def))
 120       {
 121         if (empty)
 122           {
 123             printf("%s {\n", lib);
 124             printf("  global:\n");
 125             empty = 0;
 126           }
 127         printf("\t%s;\n", sym);
 128       }
 129
 130   if (empty)
 131     {
 132       for (l in libs)
 133         if (inherit[l] == lib)
 134           inherit[l] = inherit[lib];
 135     }
 136   else if (inherit[lib])
 137     printf("} %s;\n", inherit[lib]);
 138   else
 139     printf ("\n  local:\n\t*;\n};\n");
 140 }