aboutsummaryrefslogtreecommitdiff
path: root/scripts/versions.awk
blob: d70b07bd1a7b2d6b25edae0bfd3b23792899df6a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
# Combine version map fragments into version scripts for our shared objects.
# Copyright (C) 1998-2022 Free Software Foundation, Inc.

# This script expects the following variables to be defined:
# defsfile		name of Versions.def file
# buildroot		name of build directory with trailing slash
# move_if_change	move-if-change command

# Read definitions for the versions.
BEGIN {
  lossage = 0;

  nlibs=0;
  while (getline < defsfile) {
    if (/^[a-zA-Z0-9_.]+ \{/) {
      libs[$1] = 1;
      curlib = $1;
      while (getline < defsfile && ! /^}/) {
	if ($2 == "=") {
	  renamed[curlib "::" $1] = $3;
	}
	else
	  versions[curlib "::" $1] = 1;
      }
    }
  }
  close(defsfile);

  tmpfile = buildroot "Versions.tmp";
  # POSIX sort needed.
  sort = "sort -t. -k 1,1 -k 2n,2n -k 3 > " tmpfile;
}

# GNU awk does not implement the ord and chr functions.
# <https://www.gnu.org/software/gawk/manual/html_node/Ordinal-Functions.html>
# says that they are "written very nicely", using code similar to what
# is included here.
function chr(c) {
    return sprintf("%c", c)
}

BEGIN {
    for (c = 1; c < 127; c++) {
	ord_table[chr(c)] = c;
    }
}

function ord(c) {
    if (ord_table[c]) {
	return ord_table[c];
    } else {
	printf("Invalid character reference: '%c'\n", c) > "/dev/stderr";
	++lossage;
    }
}

# Remove comment lines.
/^ *#/ {
  next;
}

# This matches the beginning of the version information for a new library.
/^[a-zA-Z0-9_.]+/ {
  actlib = $1;
  if (!libs[$1]) {
    printf("no versions defined for %s\n", $1) > "/dev/stderr";
    ++lossage;
  }
  next;
}

# This matches the beginning of a new version for the current library.
/^  [A-Za-z_]/ {
  if (renamed[actlib "::" $1])
    actver = renamed[actlib "::" $1];
  else if (!versions[actlib "::" $1] && $1 != "GLIBC_PRIVATE") {
    printf("version %s not defined for %s\n", $1, actlib) > "/dev/stderr";
    ++lossage;
  }
  else
    actver = $1;
  next;
}

# This matches lines with names to be added to the current version in the
# current library.  This is the only place where we print something to
# the intermediate file.
/^   / {
  sortver=actver
  # Ensure GLIBC_ versions come always first
  sub(/^GLIBC_/," GLIBC_",sortver)
  printf("%s %s %s\n", actlib, sortver, $0) | sort;
}

# Some targets do not set the ABI baseline for libdl.  As a result,
# symbols originally in libdl need to be moved under historic symbol
# versions, without altering the baseline version for libc itself.
/^ *!libc_pre_versions/ {
    libc_pre_versions_active = 1;
}

function libc_pre_versions() {
    # No local: * here, so that we do not have to update this script
    # if symbols are moved into libc.  The abilist files and the other
    # targets (with a real GLIBC_2.0 baseline) provide testing
    # coverage.
    printf("\
GLIBC_2.0 {\n\
};\n\
GLIBC_2.1 {\n\
} GLIBC_2.0;\n\
") > outfile;
    return "GLIBC_2.1";
}

function closeversion(name, oldname) {
  printf("  local:\n    *;\n") > outfile;
  # This version inherits from the last one only if they
  # have the same nonnumeric prefix, i.e. GLIBC_x.y and GLIBC_x.z
  # or FOO_x and FOO_y but not GLIBC_x and FOO_y.
  pfx = oldname;
  sub(/[0-9.]+/,".+",pfx);
  if (oldname == "" || name !~ pfx) print "};" > outfile;
  else printf("} %s;\n", oldname) > outfile;
}

function close_and_move(name, real_name) {
  close(name);
  system(move_if_change " " name " " real_name " >&2");
}

# ELF hash, for use with symbol versions.
function elf_hash(s, i, acc) {
  acc = 0;
  for (i = 1; i <= length(s); ++i) {
      acc = and(lshift(acc, 4) + ord(substr(s, i, 1)), 0xffffffff);
      top = and(acc, 0xf0000000);
      acc = and(xor(acc, rshift(top, 24)), compl(top));
  }
  return acc;
}

# Now print the accumulated information.
END {
  close(sort);

  if (lossage) {
    system("rm -f " tmpfile);
    exit 1;
  }

  oldlib = "";
  oldver = "";
  real_first_ver_header = buildroot "first-versions.h"
  first_ver_header = real_first_ver_header "T"
  printf("#ifndef _FIRST_VERSIONS_H\n") > first_ver_header;
  printf("#define _FIRST_VERSIONS_H\n") > first_ver_header;
  real_ldbl_compat_header = buildroot "ldbl-compat-choose.h"
  ldbl_compat_header = real_ldbl_compat_header "T"
  printf("#ifndef _LDBL_COMPAT_CHOOSE_H\n") > ldbl_compat_header;
  printf("#define _LDBL_COMPAT_CHOOSE_H\n") > ldbl_compat_header;
  printf("#ifndef LONG_DOUBLE_COMPAT\n") > ldbl_compat_header;
  printf("# error LONG_DOUBLE_COMPAT not defined\n") > ldbl_compat_header;
  printf("#endif\n") > ldbl_compat_header;
  printf("version-maps =");
  while (getline < tmpfile) {
    if ($1 != oldlib) {
      if (oldlib != "") {
	closeversion(oldver, veryoldver);
	oldver = "";
	close_and_move(outfile, real_outfile);
      }
      oldlib = $1;
      real_outfile = buildroot oldlib ".map";
      outfile = real_outfile "T";
      if ($1 == "libc" && libc_pre_versions_active) {
	  veryoldver = libc_pre_versions();
      } else {
	  veryoldver = "";
      }
      printf(" %s.map", oldlib);
    }
    if ($2 != oldver) {
      if (oldver != "") {
	closeversion(oldver, veryoldver);
	veryoldver = oldver;
      }
      oldver = $2;
      # Skip the placeholder symbol used only for empty version map.
      if ($3 == "__placeholder_only_for_empty_version_map;") {
	printf("%s {\n", $2) > outfile;
	continue;
      }
      printf("%s {\n  global:\n", $2) > outfile;
    }
    printf("   ") > outfile;
    for (n = 3; n <= NF; ++n) {
      printf(" %s", $n) > outfile;
      sym = $n;
      sub(";", "", sym);
      first_ver_macro = "FIRST_VERSION_" oldlib "_" sym;
      if (!(first_ver_macro in first_ver_seen) \
	  && oldver ~ "^GLIBC_[0-9]" \
	  && sym ~ "^[A-Za-z0-9_]*$") {
	ver_val = oldver;
	printf("#define %s_STRING \"%s\"\n", first_ver_macro, ver_val) > first_ver_header;
	printf("#define %s_HASH 0x%x\n", first_ver_macro, elf_hash(ver_val)) > first_ver_header;
	gsub("\\.", "_", ver_val);
	printf("#define %s %s\n", first_ver_macro, ver_val) > first_ver_header;
	first_ver_seen[first_ver_macro] = 1;
	if (oldlib == "libc" || oldlib == "libm") {
	  printf("#if LONG_DOUBLE_COMPAT (%s, %s)\n",
		 oldlib, ver_val) > ldbl_compat_header;
	  printf("# define LONG_DOUBLE_COMPAT_CHOOSE_%s_%s(a, b) a\n",
		 oldlib, sym) > ldbl_compat_header;
	  printf("#else\n") > ldbl_compat_header;
	  printf("# define LONG_DOUBLE_COMPAT_CHOOSE_%s_%s(a, b) b\n",
		 oldlib, sym) > ldbl_compat_header;
	  printf("#endif\n") > ldbl_compat_header;
	}
      }
    }
    printf("\n") > outfile;
  }
  printf("\n");
  printf("#endif /* first-versions.h */\n") > first_ver_header;
  printf("#endif /* ldbl-compat-choose.h */\n") > ldbl_compat_header;
  closeversion(oldver, veryoldver);
  close_and_move(outfile, real_outfile);
  close_and_move(first_ver_header, real_first_ver_header);
  close_and_move(ldbl_compat_header, real_ldbl_compat_header);
  #system("rm -f " tmpfile);
}