generate useful Nix output for sources

crosstool-ng--list-sources.patch

@@ -60,7 +60,7 @@ index 17384476..46140879 100644
          CT_Pushd "${tmp_dir}"
 -        CT_Download_${devel_vcs}
 +        if [ "${CT_COLLECT_SOURCES_FOR_NIXOS}" = "y" ]; then
-+            echo "CT_Download_${devel_vcs}: ${devel_vcs} ${devel_url} ${devel_branch} ${devel_revision}" >>"$out"
++            echo "CT_Download_${devel_vcs}: ${devel_vcs} ${devel_url} ${devel_branch} ${devel_revision} ${pkg_name}" >>"$out"
 +            mkdir "${pkg_name}"
 +        else
 +            CT_Download_${devel_vcs}

crosstool-to-nix.tcl

+#!/usr/bin/env tclsh
+
+exec -ignorestderr nix-build release.nix -A espressif-esp32-used-sources -o result-used-sources 2>@stderr
+
+set f [open result-used-sources]
+set text [read $f]
+close $f
+file delete result-used-sources
+
+set dummy_hash "1111111111111111111111111111111111111111111111111111"
+
+puts "{"
+set awaiting_digest {}
+foreach line [split $text \n] {
+  if {$line eq ""} {continue}
+
+  if {[regexp {\ADoGetFile: (http\S+|ftp\S+) -> \S+/([^/]+)\Z} $line -> url basename]} {
+    # wait for digest
+    dict set awaiting_digest $basename $url
+  } elseif {[regexp {\ADoVerifyDigest: (sha\S+), (\S+), ([^/]+)\Z} $line -> digestAlg chksum_file basename]} {
+    if {![dict exists $awaiting_digest $basename]} {
+      error "got digest for file that we didn't download: $basename"
+    }
+    set url [dict get $awaiting_digest $basename]
+    dict unset awaiting_digest $basename
+
+    puts "  \"$basename\" = fetchurl {"
+    puts "    url    = \"$url\";"
+    puts "    $digestAlg = \"TODO\";"
+    puts "  };"
+  } elseif {[regexp {\ACT_GetVersion_} $line]} {
+    # ignore and wait for corresponding CT_Download_*
+  } elseif {[regexp {\ACT_Download_git: git (\S+) (\S*) (\S*) (\S+)\Z} $line -> url branch revision basename]} {
+    if {[regexp {\Ahttps?://github.com/([^/]+)/([^/]+)\Z} $url -> owner repo]} {
+      regsub {\.git\Z} $repo {} repo
+      puts "  \"$basename\" = fetchFromGitHub {"
+      puts "    owner  = \"$owner\";"
+      puts "    repo   = \"$repo\";"
+      puts "    rev    = \"$branch$revision\";"
+      puts "    sha256 = \"$dummy_hash\";"
+      puts "  };"
+    } else {
+      puts "  \"$basename\" = fetchgit {"
+      puts "    url    = \"$url\";"
+      puts "    rev    = \"$branch$revision\";"
+      puts "    sha256 = \"$dummy_hash\";"
+      puts "  };"
+    }
+  } else {
+    error "unexpected line: [list $line]"
+  }
+}
+if {[dict size $awaiting_digest]} {
+  error "files without digest: [dict keys $awaiting_digest]"
+}
+puts "}"

sources-to-nix-syntax.sh

-#!/usr/bin/env bash
-
-cat $1
-echo TODO