Verify embedding of paths to other foreign repositories

While rules that want to be called from different repositories may not
make any assumptions about locations of their dependencies, they still
may embed path obtained via expansion of $(location ...) into their files,
even if the dependencies refer to a different repository.
Add tests verifying that this behavior is preserved.

Change-Id: I2ee6cc806e30b6e18fad9b488012169da400895b
PiperOrigin-RevId: 187030372

src/test/shell/bazel/BUILD

@@ -253,7 +253,7 @@ sh_test(
     size = "medium",
     srcs = ["external_path_test.sh"],
     data = [":test-deps"],
-    shard_count = 4,
+    shard_count = 6,
 )
 
 sh_test(

src/test/shell/bazel/external_path_test.sh

@@ -565,4 +565,129 @@ EOF
   bazel build -s @b//call:hello || fail "Expected success"
 }
 
+repo_with_embedded_foreign_path() {
+  # create, in the current working directory, a package called
+  # rule that has an implicit dependency on @data//:file.txt, a target
+  # of a different, external, repository.
+  mkdir -p rule
+  cat > rule/BUILD <<'EOF'
+genrule(
+  name = "add_preamb",
+  outs = ["add_preamb.sh"],
+  srcs = ["@data//:file.txt"], # the output actually does not depend on the contents of those files
+  cmd = " echo '#!/bin/sh' > $@; echo 'cat $(location @data//:file.txt) $$1 > $$2' >> $@",
+  visibility = ["//visibility:public"],
+)
+EOF
+  cat > rule/add_preamb.bzl <<'EOF'
+def _add_preamb_impl(ctx):
+  output = ctx.new_file(ctx.label.name + ".txt")
+  ctx.action(
+    inputs = ctx.files.src + ctx.files._add_preamb + ctx.files._preamb,
+    outputs = [output],
+    command = ["/bin/sh"] + [f.path for f in ctx.files._add_preamb] \
+              +  [f.path for f in ctx.files.src] + [output.path],
+    use_default_shell_env = True,
+    mnemonic = "AddPreamb",
+    progress_message = "Add preamble to %s" % ctx.label,
+  )
+
+add_preamb = rule(
+  implementation = _add_preamb_impl,
+  attrs = {
+    "src" : attr.label(allow_files=True),
+    "_add_preamb" : attr.label(cfg="host", allow_files=True,
+                               default = Label("//rule:add_preamb")),
+    # knowledge of which paths are embedded is duplicated here!
+    "_preamb" : attr.label(cfg="host", allow_files=True,
+                               default = Label("@data//:file.txt")),
+  },
+  outputs = {"with_preamb": "%{name}.txt"},
+)
+EOF
+}
+
+repo_data_file() {
+  # Create, in the current directory, an archive of a data repository containing
+  # //:file.txt, and add a corresponding entry to ./main/WORKSPACE.
+  mkdir data
+  cat > data/file.txt <<'EOF'
+Copyright ...
+EOF
+  cat > data/BUILD <<'EOF'
+exports_files(["file.txt"], visibility = ["//visibility:public"])
+EOF
+  tar cvf data.tar data
+  rm -rf data
+  cat >> main/WORKSPACE <<EOF
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+http_archive(
+  name="data",
+  strip_prefix="data",
+  urls=["file://$(pwd)/data.tar"],
+)
+EOF
+}
+
+test_embedded_foreign_paths_local() {
+  # Verify that a rule in a local repository can embed a path to a foreigh
+  # repository
+  WRKDIR=$(mktemp -d "${TEST_TMPDIR}/testXXXXXX")
+  cd "${WRKDIR}"
+
+  mkdir main
+  repo_data_file
+
+  cd main
+  repo_with_embedded_foreign_path
+  echo Hello world > foo.txt
+  cat > BUILD <<'EOF'
+load('//rule:add_preamb.bzl', 'add_preamb')
+
+add_preamb(name='main', src='foo.txt')
+EOF
+
+  bazel build -s //:main || fail 'Expected success'
+  cat `bazel info bazel-bin`/main.txt | grep 'world' \
+    || fail "not the expected output"
+  cat `bazel info bazel-bin`/main.txt | grep 'Copyright' \
+    || fail "not the expected output"
+}
+
+test_embedded_foreign_paths_remote() {
+  # Verify that a rule in a local repository can embed a path to a foreigh
+  # repository
+  WRKDIR=$(mktemp -d "${TEST_TMPDIR}/testXXXXXX")
+  cd "${WRKDIR}"
+
+  mkdir main
+  repo_data_file
+
+  mkdir rule
+  (cd rule && repo_with_embedded_foreign_path)
+  tar cvf rule.tar rule
+  rm -rf rule
+  cat >> main/WORKSPACE <<EOF
+http_archive(
+  name="rule",
+  strip_prefix="rule",
+  urls=["file://$(pwd)/rule.tar"],
+)
+EOF
+
+  cd main
+  echo Hello world > foo.txt
+  cat > BUILD <<'EOF'
+load('@rule//rule:add_preamb.bzl', 'add_preamb')
+
+add_preamb(name='main', src='foo.txt')
+EOF
+
+  bazel build -s //:main || fail 'Expected success'
+  cat `bazel info bazel-bin`/main.txt | grep 'world' \
+    || fail "not the expected output"
+  cat `bazel info bazel-bin`/main.txt | grep 'Copyright' \
+    || fail "not the expected output"
+}
+
 run_suite "path tests for multiple repositories"