Squashed 'third_party/rules_rust/' content from commit bf59038ca

git-subtree-dir: third_party/rules_rust
git-subtree-split: bf59038cac11798cbaef9f3bf965bad8182b97fa
Signed-off-by: Brian Silverman <bsilver16384@gmail.com>
Change-Id: I5a20e403203d670df467ea97dde9a4ac40339a8d
diff --git a/util/fetch_shas.sh b/util/fetch_shas.sh
new file mode 100755
index 0000000..2a538c1
--- /dev/null
+++ b/util/fetch_shas.sh
@@ -0,0 +1,70 @@
+#!/usr/bin/env bash
+
+# Enumerates the list of expected downloadable files, loads the SHAs for each file, then
+# dumps the result to //rust:known_shas.bzl
+
+export LC_ALL=C
+
+# Detect workspace root
+if [[ -z "${BUILD_WORKSPACE_DIRECTORY}" ]]; then
+    SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"
+    BUILD_WORKSPACE_DIRECTORY="$( dirname "${SCRIPT_DIR}")"
+fi
+
+TOOLS="$(cat "${BUILD_WORKSPACE_DIRECTORY}/util/fetch_shas_TOOLS.txt")"
+HOST_TOOLS="$(cat "${BUILD_WORKSPACE_DIRECTORY}/util/fetch_shas_HOST_TOOLS.txt")"
+TARGETS="$(cat "${BUILD_WORKSPACE_DIRECTORY}/util/fetch_shas_TARGETS.txt")"
+VERSIONS="$(cat "${BUILD_WORKSPACE_DIRECTORY}/util/fetch_shas_VERSIONS.txt")"
+BETA_ISO_DATES="$(cat "${BUILD_WORKSPACE_DIRECTORY}/util/fetch_shas_BETA_ISO_DATES.txt")"
+NIGHTLY_ISO_DATES="$(cat "${BUILD_WORKSPACE_DIRECTORY}/util/fetch_shas_NIGHTLY_ISO_DATES.txt")"
+
+enumerate_keys() {
+  for TOOL in $TOOLS
+  do
+    for TARGET in $TARGETS
+    do
+      for VERSION in $VERSIONS
+      do
+        echo "$TOOL-$VERSION-$TARGET"
+      done
+
+      for ISO_DATE in $BETA_ISO_DATES
+      do
+        echo "$ISO_DATE/$TOOL-beta-$TARGET"
+      done
+
+      for ISO_DATE in $NIGHTLY_ISO_DATES
+      do
+        echo "$ISO_DATE/$TOOL-nightly-$TARGET"
+      done
+    done
+  done
+
+  for HOST_TOOL in $HOST_TOOLS
+  do
+    for VERSION in $VERSIONS
+    do
+      echo "$HOST_TOOL-$VERSION"
+    done
+  done
+}
+
+emit_bzl_file_contents() {
+  echo "$@" \
+    | parallel --trim lr -d ' ' --will-cite 'printf "%s %s\n", {}, $(curl --fail https://static.rust-lang.org/dist/{}.tar.gz.sha256 | cut -f1 -d" ")' \
+    | sed "s/,//g" \
+    | grep -v " $" \
+    > /tmp/reload_shas_shalist.txt
+
+  echo "\"\"\"A module containing a mapping of Rust tools to checksums"
+  echo ""
+  echo "This is a generated file -- see //util:fetch_shas"
+  echo "\"\"\""
+  echo ""
+  echo "FILE_KEY_TO_SHA = {"
+  cat /tmp/reload_shas_shalist.txt | sed '/^[[:space:]]*$/d' | sort | awk '{print "    \"" $1 "\": \"" $2 "\","}'
+  echo "}"
+  rm /tmp/reload_shas_shalist.txt
+}
+
+echo "$(emit_bzl_file_contents $(enumerate_keys))" > "${BUILD_WORKSPACE_DIRECTORY}/rust/known_shas.bzl"