Minor nogo restructuring.

PiperOrigin-RevId: 336343819

3 files changed, 71 insertions, 30 deletions

diff --git a/tools/nogo/BUILD b/tools/nogo/BUILD
index 313c56410..dd4b46f58 100644
--- a/tools/nogo/BUILD
+++ b/tools/nogo/BUILD
@@ -13,6 +13,12 @@ nogo_stdlib(
     visibility = ["//visibility:public"],
 )
 
+sh_binary(
+    name = "gentest",
+    srcs = ["gentest.sh"],
+    visibility = ["//visibility:public"],
+)
+
 go_library(
     name = "nogo",
     srcs = [
diff --git a/tools/nogo/defs.bzl b/tools/nogo/defs.bzl
index e780a83e8..c6fcfd402 100644
--- a/tools/nogo/defs.bzl
+++ b/tools/nogo/defs.bzl
@@ -275,36 +275,19 @@ nogo_aspect = go_rule(
 def _nogo_test_impl(ctx):
     """Check nogo findings."""
 
-    # Build a runner that checks for the existence of the facts file. Note that
-    # the actual build will fail in the case of a broken analysis. We things
-    # this way so that any test applied is effectively pushed down to all
-    # upstream dependencies through the aspect.
-    inputs = []
-    findings = []
-    runner = ctx.actions.declare_file("%s-executer" % ctx.label.name)
-    runner_content = ["#!/bin/bash"]
-    for dep in ctx.attr.deps:
-        # Extract the findings.
-        info = dep[NogoInfo]
-        inputs.append(info.findings)
-        findings.append(info.findings)
-
-        # Include all source files, transitively. This will make this target
-        # "directly affected" for the purpose of build analysis.
-        inputs += info.srcs
-
-        # If there are findings, dump them and fail.
-        runner_content.append("if [[ -s \"%s\" ]]; then cat \"%s\" && exit 1; fi" % (
-            info.findings.short_path,
-            info.findings.short_path,
-        ))
-
-        # Otherwise, draw a sweet unicode checkmark with the package name (in green).
-        runner_content.append("echo -e \"\\033[0;32m\\xE2\\x9C\\x94\\033[0;31m\\033[0m %s\"" % info.importpath)
-    runner_content.append("exit 0\n")
-    ctx.actions.write(runner, "\n".join(runner_content), is_executable = True)
+    # Build a runner that checks the facts files.
+    findings = [dep[NogoInfo].findings for dep in ctx.attr.deps]
+    runner = ctx.actions.declare_file(ctx.label.name)
+    ctx.actions.run(
+        inputs = findings + ctx.files.srcs,
+        outputs = [runner],
+        tools = depset(ctx.files._gentest),
+        executable = ctx.files._gentest[0],
+        mnemonic = "Gentest",
+        progress_message = "Generating %s" % ctx.label,
+        arguments = [runner.path] + [f.path for f in findings],
+    )
     return [DefaultInfo(
-        runfiles = ctx.runfiles(files = inputs),
         executable = runner,
     )]
 
@@ -313,14 +296,19 @@ _nogo_test = rule(
     attrs = {
         # deps should have only a single element.
         "deps": attr.label_list(aspects = [nogo_aspect]),
+        # srcs exist here only to ensure that this target is
+        # directly affected by changes to the source files.
+        "srcs": attr.label_list(allow_files = True),
+        "_gentest": attr.label(default = "//tools/nogo:gentest"),
     },
     test = True,
 )
 
-def nogo_test(name, library, **kwargs):
+def nogo_test(name, srcs, library, **kwargs):
     tags = kwargs.pop("tags", []) + ["nogo"]
     _nogo_test(
         name = name,
+        srcs = srcs,
         deps = [library],
         tags = tags,
         **kwargs
diff --git a/tools/nogo/gentest.sh b/tools/nogo/gentest.sh
new file mode 100755
index 000000000..033da11ad
--- /dev/null
+++ b/tools/nogo/gentest.sh
@@ -0,0 +1,47 @@
+#!/bin/bash
+# Copyright 2019 The gVisor Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set -euo pipefail
+
+if [[ "$#" -lt 2 ]]; then
+  echo "usage: $0 <output> <findings...>"
+  exit 2
+fi
+declare violations=0
+declare output=$1
+shift
+
+# Start the script.
+echo "#!/bin/sh" > "${output}"
+
+# Read a list of findings files.
+declare filename
+declare line
+for filename in "$@"; do
+  if [[ -z "${filename}" ]]; then
+    continue
+  fi
+  while read -r line; do
+    violations=$((${violations}+1));
+    echo "echo -e '\\033[0;31m${line}\\033[0;31m\\033[0m'" >> "${output}"
+  done < "${filename}"
+done
+
+# Show violations.
+if [[ "${violations}" -eq 0 ]]; then
+  echo "echo -e '\\033[0;32mPASS\\033[0;31m\\033[0m'" >> "${output}"
+else
+  echo "exit 1" >> "${output}"
+fi