From d33a27b272a68752e67b54b2f09912d4786ae480 Mon Sep 17 00:00:00 2001
From: Silvan Mosberger <contact@infinisil.com>
Date: Fri, 19 Mar 2021 15:54:25 +0100
Subject: [PATCH] Recursively collect which attributes derivations depend on

Exposes $out/nix-support/attribute-deps, containing all inputs of the
derivation recursively as attribute paths
---
 pkgs/stdenv/generic/make-derivation.nix | 17 +++++++++++++++++
 pkgs/stdenv/generic/setup.sh            | 14 ++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/pkgs/stdenv/generic/make-derivation.nix b/pkgs/stdenv/generic/make-derivation.nix
index 13a7a03d6a8b89f..57b5dd74467c8bc 100644
--- a/pkgs/stdenv/generic/make-derivation.nix
+++ b/pkgs/stdenv/generic/make-derivation.nix
@@ -115,6 +115,22 @@ in rec {
         else lib.subtractLists hardeningDisable (defaultHardeningFlags ++ hardeningEnable);
       # hardeningDisable additionally supports "all".
       erroneousHardeningFlags = lib.subtractLists supportedHardeningFlags (hardeningEnable ++ lib.remove "all" hardeningDisable);
+
+      allDeps = depsBuildBuild
+        ++ depsBuildBuildPropagated
+        ++ nativeBuildInputs
+        ++ propagatedNativeBuildInputs
+        ++ depsBuildTarget
+        ++ depsBuildTargetPropagated
+        ++ depsHostHost
+        ++ depsHostHostPropagated
+        ++ buildInputs
+        ++ propagatedBuildInputs
+        ++ depsTargetTarget
+        ++ depsTargetTargetPropagated;
+
+      attributeDeps = map (d: lib.concatStringsSep "." d.__path) (lib.filter (d: d ? __path) allDeps);
+
     in if builtins.length erroneousHardeningFlags != 0
     then abort ("mkDerivation was called with unsupported hardening flags: " + lib.generators.toPretty {} {
       inherit erroneousHardeningFlags hardeningDisable hardeningEnable supportedHardeningFlags;
@@ -200,6 +216,7 @@ in rec {
           builder = attrs.realBuilder or stdenv.shell;
           args = attrs.args or ["-e" (attrs.builder or ./default-builder.sh)];
           inherit stdenv;
+          inherit attributeDeps;
 
           # The `system` attribute of a derivation has special meaning to Nix.
           # Derivations set it to choose what sort of machine could be used to
diff --git a/pkgs/stdenv/generic/setup.sh b/pkgs/stdenv/generic/setup.sh
index 7168ce4084c87b3..bfc78c7344e0811 100644
--- a/pkgs/stdenv/generic/setup.sh
+++ b/pkgs/stdenv/generic/setup.sh
@@ -334,6 +334,7 @@ declare -a propagatedDepFilesVars=(
 # Platform offsets: build = -1, host = 0, target = 1
 declare -a allPlatOffsets=(-1 0 1)
 
+declare -a attributeDepsArr=($attributeDeps)
 
 # Mutually-recursively find all build inputs. See the dependency section of the
 # stdenv chapter of the Nixpkgs manual for the specification this algorithm
@@ -427,6 +428,12 @@ findInputs() {
             done
         done
     done
+
+    if [[ -f "$pkg"/nix-support/attribute-deps ]]; then
+        for p in $(cat "$pkg/nix-support/attribute-deps"); do
+            attributeDepsArr+=("$p")
+        done
+    fi
 }
 
 # Make sure all are at least defined as empty
@@ -1160,6 +1167,13 @@ fixupPhase() {
         substituteAll "$setupHook" "${!outputDev}/nix-support/setup-hook"
     fi
 
+    for a in "${attributeDepsArr[@]}"; do
+        for output in $outputs; do
+            mkdir -p "${!output}/nix-support"
+            echo "$a" >> "${!output}/nix-support/attribute-deps"
+        done
+    done
+
     # TODO(@Ericson2314): Remove after https://github.com/NixOS/nixpkgs/pull/31414
     if [ -n "${setupHooks:-}" ]; then
         mkdir -p "${!outputDev}/nix-support"