Modify type of ERIS­Dhall manifest

Make the Dhall manifest have a general type, with the exception
of the top-level attrset which can be made general with "toMap".

overlay/default.nix

@@ -264,10 +264,13 @@ in nullPkgs // {
 
   solo5-tools = callPackage ./solo5-tools { };
 
-  stdenv = overrideHost (old: {
-    extraNativeBuildInputs = old.extraNativeBuildInputs
-      ++ [ final.buildPackages.erisPatchHook ];
-  }) prev.stdenv;
+  stdenv = if prev.stdenv.hostPlatform.isGenode then
+    stdenv.override (prev': {
+      extraNativeBuildInputs = prev'.extraNativeBuildInputs
+        ++ [ final.buildPackages.erisPatchHook ];
+    })
+  else
+    prev.stdenv;
 
   tor = overrideAttrsHost (attrs: {
     patches = attrs.patches or [ ] ++ [

overlay/eris-patch-hook/eris_patch.nim

@@ -3,6 +3,20 @@ import cbor, dhall/[render, terms], eris
 
 const selfDescribedCbor = 55799
 
+type
+  Manifest = Table[string, ManifestEntry]
+  ManifestEntry = object
+    cap, path: string
+    closure: Table[string, string]
+
+proc parseManifestFile(path: string): Manifest =
+  let js = parseFile(path)
+  for key, val in js.pairs:
+    var entry: ManifestEntry
+    entry.cap = val["cap"].getStr
+    entry.path = val["path"].getStr
+    result[key] = entry
+
 proc writeErisLinks(path: string; node: CborNode) =
   # Inspired by "Package Metadata for Core Files"
   # - https://systemd.io/COREDUMP_PACKAGE_METADATA/
@@ -25,16 +39,33 @@ proc toCbor(cap: ErisCap): CborNode =
   result = initCborBytes(cap.bytes)
   result.tag = erisCborTag
 
-proc toDhall(js: JsonNode): Value =
-  case js.kind
-  of JString:
-    result = newValue(js.str)
-  of JObject:
-    result = newRecordLiteral(js.fields.len)
-    for key, val in js.fields.pairs:
-      result.table[key] = val.toDhall
-  else:
-    raiseAssert "unhandled JSON value"
+proc toDhall(entry: ManifestEntry): Value =
+  var closure = newSeqOfCap[Value](entry.closure.len+1)
+  closure.add newRecordLiteral(
+    { "cap": newValue $entry.cap, "path": newValue entry.path})
+  for path, urn in entry.closure.pairs:
+    closure.add newRecordLiteral(
+      { "cap": newValue urn, "path": newValue path })
+  newRecordLiteral {
+      "cap": newValue entry.cap,
+      "closure": newValue closure,
+    }
+
+proc toDhall(manifest: Manifest): Value =
+  result = newRecordLiteral(manifest.len)
+  for name, entry in manifest.pairs:
+    result.table[name] = entry.toDhall
+
+proc toJson(entry: ManifestEntry): JsonNode =
+  var closure = newJObject()
+  for path, urn in entry.closure.pairs:
+    closure[path] = %urn
+  %*{ "cap": entry.cap, "closure": closure, "path": entry.path }
+
+proc toJson(manifest: Manifest): JsonNode =
+  result = newJObject()
+  for name, entry in manifest.pairs:
+    result[name] = entry.toJSON
 
 proc isElf(path: string): bool =
   var magic: array[4, char]
@@ -66,7 +97,7 @@ proc main =
     erisLinks: CborNode
 
   var
-    outputManifests = initTable[string, JsonNode]()
+    outputManifests = initTable[string, Manifest]()
     pendingFiles = initDeque[PendingFile]()
     failed = false
   if getEnv("outputs") == "":
@@ -78,7 +109,7 @@ proc main =
     if fileExists(outputRoot / jsonManifestSubPath):
       stderr.writeLine "Not running ERIS patch hook again"
       quit 0
-    outputManifests[outputRoot] = newJObject()
+    outputManifests[outputRoot] = Manifest()
 
   let buildInputs = getEnv("buildInputs").splitWhitespace
 
@@ -149,10 +180,10 @@ proc main =
         let manifestPath = storePath / jsonManifestSubPath
         if fileExists(manifestPath):
           let
-            manifest = parseFile(manifestPath)
+            manifest = parseManifestFile(manifestPath)
             entry = manifest[filePath.extractFilename]
-          for path, urn in entry["closure"].pairs:
-            result[path] = parseErisUrn urn.getStr
+          for path, urn in entry.closure.pairs:
+            result[path] = parseErisUrn urn
             let otherClosure = fileClosure(path)
             for otherPath, otherCap in otherClosure.pairs:
               # merge the closure of the dependency
@@ -196,7 +227,7 @@ proc main =
                 pendingFiles.addLast(pendingFile)
                 break selfReferenceCheck
       var
-        closure = newJObject()
+        closure = initTable[string, string]()
         replaceCmd = patchelf & " --set-rpath '' " & filePath
       for need, replacementPath in pendingFile.replacements.pairs:
         if replacementPath == "": continue
@@ -204,11 +235,11 @@ proc main =
           cap = fileCap(replacementPath)
           urn = $cap
         stderr.writeLine "replace reference to ", need, " with ", urn
-        closure[replacementPath] = %urn
+        closure[replacementPath] = urn
         pendingFile.erisLinks[ replacementPath.toCbor] = cap.toCbor
         replaceCmd.add(" --replace-needed $# $#" % [need, urn])
         for path, cap in fileClosure(replacementPath).pairs:
-          closure[path] = %($cap)
+          closure[path] = $cap
           pendingFile.erisLinks[path.toCbor] = cap.toCbor
 
       if runPatchelf and pendingFile.replacements.len != 0:
@@ -238,11 +269,12 @@ proc main =
           quit("Adding note to $1 failed" % pendingFile.filePath)
         moveFile(tmpFile, pendingFile.filePath)
 
-      outputManifests[pendingFile.outputRoot][filePath.extractFilename] = %* {
-        "cap": $fileCap(filePath),
-        "closure": closure,
-        "path": filePath
-      }
+      outputManifests[pendingFile.outputRoot][filePath.extractFilename] =
+        ManifestEntry(
+            cap: $fileCap(filePath),
+            closure: closure,
+            path: filePath,
+          )
 
     if pendingFiles.len == prevPrevLen:
       failed = true
@@ -260,7 +292,7 @@ proc main =
     for outputRoot, manifest in outputManifests:
       let supportDir = outputRoot / "nix-support"
       createDir(supportDir)
-      writeFile(outputRoot / jsonManifestSubPath, $manifest)
-      writeFile(outputRoot / dhallManifestSubPath, $(manifest.toDhall))
+      writeFile(outputRoot / jsonManifestSubPath, $manifest.toJson)
+      writeFile(outputRoot / dhallManifestSubPath, $manifest.toDhall)
 
 main()