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
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
|
#! @perl@ -w
use strict;
use Cwd 'abs_path';
use IO::Handle;
use File::Path;
use File::Basename;
use File::Compare;
use JSON::PP;
STDOUT->autoflush(1);
$SIG{__WARN__} = sub { warn "warning: ", @_ };
$SIG{__DIE__} = sub { die "error: ", @_ };
my $out = $ENV{"out"};
my $extraPrefix = $ENV{"extraPrefix"};
my @pathsToLink = split ' ', $ENV{"pathsToLink"};
sub isInPathsToLink {
my $path = shift;
$path = "/" if $path eq "";
foreach my $elem (@pathsToLink) {
return 1 if
$elem eq "/" ||
(substr($path, 0, length($elem)) eq $elem
&& (($path eq $elem) || (substr($path, length($elem), 1) eq "/")));
}
return 0;
}
# Returns whether a path in one of the linked packages may contain
# files in one of the elements of pathsToLink.
sub hasPathsToLink {
my $path = shift;
foreach my $elem (@pathsToLink) {
return 1 if
$path eq "" ||
(substr($elem, 0, length($path)) eq $path
&& (($path eq $elem) || (substr($elem, length($path), 1) eq "/")));
}
return 0;
}
# Similar to `lib.isStorePath`
sub isStorePath {
my $path = shift;
my $storePath = "@storeDir@";
return substr($path, 0, 1) eq "/" && dirname($path) eq $storePath;
}
# For each activated package, determine what symlinks to create.
my %symlinks;
# Add all pathsToLink and all parent directories.
#
# For "/a/b/c" that will include
# [ "", "/a", "/a/b", "/a/b/c" ]
#
# That ensures the whole directory tree needed by pathsToLink is
# created as directories and not symlinks.
$symlinks{""} = ["", 0];
for my $p (@pathsToLink) {
my @parts = split '/', $p;
my $cur = "";
for my $x (@parts) {
$cur = $cur . "/$x";
$cur = "" if $cur eq "/";
$symlinks{$cur} = ["", 0];
}
}
sub findFiles;
sub findFilesInDir {
my ($relName, $target, $ignoreCollisions, $checkCollisionContents, $priority) = @_;
opendir DIR, "$target" or die "cannot open `$target': $!";
my @names = readdir DIR or die;
closedir DIR;
foreach my $name (@names) {
next if $name eq "." || $name eq "..";
findFiles("$relName/$name", "$target/$name", $name, $ignoreCollisions, $checkCollisionContents, $priority);
}
}
sub checkCollision {
my ($path1, $path2) = @_;
if (! -e $path1 || ! -e $path2) {
return 0;
}
my $stat1 = (stat($path1))[2];
my $stat2 = (stat($path2))[2];
if ($stat1 != $stat2) {
warn "different permissions in `$path1' and `$path2': "
. sprintf("%04o", $stat1 & 07777) . " <-> "
. sprintf("%04o", $stat2 & 07777);
return 0;
}
return compare($path1, $path2) == 0;
}
sub prependDangling {
my $path = shift;
return (-l $path && ! -e $path ? "dangling symlink " : "") . "`$path'";
}
sub findFiles {
my ($relName, $target, $baseName, $ignoreCollisions, $checkCollisionContents, $priority) = @_;
# The store path must not be a file
if (-f $target && isStorePath $target) {
die "The store path $target is a file and can't be merged into an environment using pkgs.buildEnv!";
}
# Urgh, hacky...
return if
$relName eq "/propagated-build-inputs" ||
$relName eq "/nix-support" ||
$relName =~ /info\/dir/ ||
( $relName =~ /^\/share\/mime\// && !( $relName =~ /^\/share\/mime\/packages/ ) ) ||
$baseName eq "perllocal.pod" ||
$baseName eq "log" ||
! (hasPathsToLink($relName) || isInPathsToLink($relName));
my ($oldTarget, $oldPriority) = @{$symlinks{$relName} // [undef, undef]};
# If target doesn't exist, create it. If it already exists as a
# symlink to a file (not a directory) in a lower-priority package,
# overwrite it.
if (!defined $oldTarget || ($priority < $oldPriority && ($oldTarget ne "" && ! -d $oldTarget))) {
# If target is a dangling symlink, emit a warning.
if (-l $target && ! -e $target) {
my $link = readlink $target;
warn "creating dangling symlink `$out$extraPrefix/$relName' -> `$target' -> `$link'\n";
}
$symlinks{$relName} = [$target, $priority];
return;
}
# If target already exists and both targets resolves to the same path, skip
if (
defined $oldTarget && $oldTarget ne "" &&
defined abs_path($target) && defined abs_path($oldTarget) &&
abs_path($target) eq abs_path($oldTarget)
) {
# Prefer the target that is not a symlink, if any
if (-l $oldTarget && ! -l $target) {
$symlinks{$relName} = [$target, $priority];
}
return;
}
# If target already exists as a symlink to a file (not a
# directory) in a higher-priority package, skip.
if (defined $oldTarget && $priority > $oldPriority && $oldTarget ne "" && ! -d $oldTarget) {
return;
}
# If target is supposed to be a directory but it isn't, die with an error message
# instead of attempting to recurse into it, only to fail then.
# This happens e.g. when pathsToLink contains a non-directory path.
if ($oldTarget eq "" && ! -d $target) {
die "not a directory: `$target'\n";
}
unless (-d $target && ($oldTarget eq "" || -d $oldTarget)) {
# Prepend "dangling symlink" to paths if applicable.
my $targetRef = prependDangling($target);
my $oldTargetRef = prependDangling($oldTarget);
if ($ignoreCollisions) {
warn "collision between $targetRef and $oldTargetRef\n" if $ignoreCollisions == 1;
return;
} elsif ($checkCollisionContents && checkCollision($oldTarget, $target)) {
return;
} else {
die "collision between $targetRef and $oldTargetRef\n";
}
}
findFilesInDir($relName, $oldTarget, $ignoreCollisions, $checkCollisionContents, $oldPriority) unless $oldTarget eq "";
findFilesInDir($relName, $target, $ignoreCollisions, $checkCollisionContents, $priority);
$symlinks{$relName} = ["", $priority]; # denotes directory
}
my %done;
my %postponed;
sub addPkg {
my ($pkgDir, $ignoreCollisions, $checkCollisionContents, $priority) = @_;
return if (defined $done{$pkgDir});
$done{$pkgDir} = 1;
findFiles("", $pkgDir, "", $ignoreCollisions, $checkCollisionContents, $priority);
my $propagatedFN = "$pkgDir/nix-support/propagated-user-env-packages";
if (-e $propagatedFN) {
open PROP, "<$propagatedFN" or die;
my $propagated = <PROP>;
close PROP;
my @propagated = split ' ', $propagated;
foreach my $p (@propagated) {
$postponed{$p} = 1 unless defined $done{$p};
}
}
}
# Read packages list.
my $pkgs;
if (exists $ENV{"pkgsPath"}) {
open FILE, $ENV{"pkgsPath"};
$pkgs = <FILE>;
close FILE;
} else {
$pkgs = $ENV{"pkgs"}
}
# Symlink to the packages that have been installed explicitly by the
# user.
for my $pkg (@{decode_json $pkgs}) {
for my $path (@{$pkg->{paths}}) {
addPkg($path,
$ENV{"ignoreCollisions"} eq "1",
$ENV{"checkCollisionContents"} eq "1",
$pkg->{priority})
if -e $path;
}
}
# Symlink to the packages that have been "propagated" by packages
# installed by the user (i.e., package X declares that it wants Y
# installed as well). We do these later because they have a lower
# priority in case of collisions.
my $priorityCounter = 1000; # don't care about collisions
while (scalar(keys %postponed) > 0) {
my @pkgDirs = keys %postponed;
%postponed = ();
foreach my $pkgDir (sort @pkgDirs) {
addPkg($pkgDir, 2, $ENV{"checkCollisionContents"} eq "1", $priorityCounter++);
}
}
# Create the symlinks.
my $nrLinks = 0;
foreach my $relName (sort keys %symlinks) {
my ($target, $priority) = @{$symlinks{$relName}};
my $abs = "$out" . "$extraPrefix" . "/$relName";
next unless isInPathsToLink $relName;
if ($target eq "") {
#print "creating directory $relName\n";
mkpath $abs or die "cannot create directory `$abs': $!";
} else {
#print "creating symlink $relName to $target\n";
symlink $target, $abs ||
die "error creating link `$abs': $!";
$nrLinks++;
}
}
print STDERR "created $nrLinks symlinks in user environment\n";
my $manifest = $ENV{"manifest"};
if ($manifest) {
symlink($manifest, "$out/manifest") or die "cannot create manifest";
}
|