WIP: deterministic evaluation of expressions/derivations

corepkgs/local.mk

@@ -1,4 +1,4 @@
-corepkgs_FILES = nar.nix buildenv.nix buildenv.pl unpack-channel.nix derivation.nix fetchurl.nix imported-drv-to-derivation.nix
+corepkgs_FILES = nar.nix buildenv.nix buildenv.pl unpack-channel.nix derivation.nix fetchurl.nix imported-drv-to-derivation.nix reproducable-derivation.nix
 
 $(foreach file,config.nix $(corepkgs_FILES),$(eval $(call install-data-in,$(d)/$(file),$(datadir)/nix/corepkgs)))
 

corepkgs/reproducable-derivation.nix

@@ -0,0 +1,15 @@
+{ recording, expressions}:
+with import ./config.nix;
+derivation {
+  name = "source-closure";
+  builder = shell;
+  args = ["-e" (__toFile "name" ''
+    #!/bin/bash
+    ${coreutils}/mkdir -p $out/nix-support
+    ${coreutils}/cp ${__toFile "deterministic-recording" recording} $out/nix-support/recording.nix
+    ${coreutils}/cp ${__toFile "expressions" expressions} $out/nix-support/expressions.nix
+    echo "__playback { sources = { \"$out\" = ./.; }; functions = []; }" > $out/default.nix
+    echo "(__playback (import ./nix-support/recording.nix) (import ./nix-support/expressions.nix))" >> $out/default.nix
+    '')];
+  system = builtins.currentSystem;
+}

scripts/nix-build.in

@@ -18,6 +18,7 @@ my $pure = 0;
 my $fromArgs = 0;
 my $packages = 0;
 my $interactive = 1;
+my $playback = 0;
 
 my @instArgs = ();
 my @buildArgs = ();
@@ -124,6 +125,17 @@ for (my $n = 0; $n < scalar @ARGV; $n++) {
         $n += 2;
     }
 
+    elsif ($arg eq "--playback") {
+        die "$0: '$arg' requires an argument\n" unless $n + 1 < scalar @ARGV;
+        push @instArgs, ($arg, $ARGV[$n + 1]);
+        $playback = 1;
+        $n++;
+    }
+
+    elsif ($arg eq "--record") {
+        push @instArgs, $arg;
+    }
+
     elsif ($arg eq "--max-jobs" || $arg eq "-j" || $arg eq "--max-silent-time" || $arg eq "--log-type" || $arg eq "--cores" || $arg eq "--timeout" || $arg eq '--add-root') {
         $n++;
         die "$0: ‘$arg’ requires an argument\n" unless $n < scalar @ARGV;
@@ -219,6 +231,7 @@ for (my $n = 0; $n < scalar @ARGV; $n++) {
 }
 
 die "$0: ‘-p’ and ‘-E’ are mutually exclusive\n" if $packages && $fromArgs;
+die "$0: with --playback you can't supply expressions\n" if $playback && (scalar @exprs > 0 || $packages);
 
 if ($packages) {
     push @instArgs, "--expr";
@@ -243,8 +256,9 @@ foreach my $expr (@exprs) {
         $expr = dirname(Cwd::abs_path($script)) . "/" . $expr
             if $inShebang && !$packages && $expr !~ /^\//;
 
+        my @expression = $playback ? () : ($expr);
         # !!! would prefer the perl 5.8.0 pipe open feature here.
-        my $pid = open(DRVPATHS, "-|") || exec "$Nix::Config::binDir/nix-instantiate", "--add-root", $drvLink, "--indirect", @instArgs, $expr;
+        my $pid = open(DRVPATHS, "-|") || exec "$Nix::Config::binDir/nix-instantiate", "--add-root", $drvLink, "--indirect", @instArgs, @expression;
         while (<DRVPATHS>) {chomp; push @drvPaths, $_;}
         if (!close DRVPATHS) {
             die "nix-instantiate killed by signal " . ($? & 127) . "\n" if ($? & 127);

src/libexpr/common-opts.cc

@@ -52,15 +52,15 @@ bool parseSearchPathArg(Strings::iterator & i,
 }
 
 
-Path lookupFileArg(EvalState & state, string s)
+Path lookupFileArg(EvalState & state, string s, string currentPath)
 {
     if (isUri(s))
         return downloadFileCached(s, true);
     else if (s.size() > 2 && s.at(0) == '<' && s.at(s.size() - 1) == '>') {
         Path p = s.substr(1, s.size() - 2);
         return state.findFile(p);
     } else
-        return absPath(s);
+        return absPath(s, currentPath);
 }
 
 

src/libexpr/common-opts.hh

@@ -13,6 +13,6 @@ Bindings * evalAutoArgs(EvalState & state, std::map<string, string> & in);
 bool parseSearchPathArg(Strings::iterator & i,
     const Strings::iterator & argsEnd, Strings & searchPath);
 
-Path lookupFileArg(EvalState & state, string s);
+Path lookupFileArg(EvalState & state, string s, string currentPath = "");
 
 }