WIP

.gitignore

@@ -25,4 +25,8 @@ DerivedData
 Tests/Fixtures/.build/
 
 # VSCode
-.vscode/*
+.vscode/*
+
+# Bazel
+bazel-*
+/MODULE.bazel.lock

MODULE.bazel

@@ -0,0 +1,8 @@
+module(
+    name = "periphery",
+    version = "0.0.0",
+    compatibility_level = 1,
+)
+
+internal = use_extension("//bazel:extensions.bzl", "internal")
+use_repo(internal, "periphery_generated")

Sources/Frontend/Commands/BazelCommand.swift

@@ -0,0 +1,63 @@
+import ArgumentParser
+import Foundation
+import Shared
+import SystemPackage
+
+struct BazelScanCommand: FrontendCommand {
+    static let configuration = CommandConfiguration(
+        commandName: "bazel-scan",
+        abstract: "Scan for unused code (for Bazel projects)"
+    )
+
+    @Option(help: "Bazel top-level targets expression")
+    var target: String = "//..."
+
+    @Option(help: "Path to configuration file. By default Periphery will look for .periphery.yml in the current directory")
+    var config: FilePath = FilePath(".periphery.yml")
+
+    func run() throws {
+      guard let executablePath = Bundle.main.executablePath else {
+        // TODO: throw?
+        return
+      }
+
+      let buildFilePath = FilePath("/var/tmp/periphery_bazel/generated/BUILD")
+      let fileManager = FileManager.default
+      try fileManager.createDirectory(at: buildFilePath.removingLastComponent().url, withIntermediateDirectories: true)
+      try? fileManager.removeItem(at: buildFilePath.url)
+      defer {
+        try? fileManager.removeItem(at: buildFilePath.url)
+      }
+
+      let shell = Shell.shared
+      let query = "kind(\'apple_framework_packaging rule|ios_unit_test rule|ios_ui_test rule|ios_application rule\', rdeps(//..., '\(target)') union deps('\(target)'))"
+      let output = try shell.exec(["bazel", "query", "--noshow_progress", "--ui_event_filters=-info,-debug,-warning", query])
+      let deps = output.split(separator: "\n").map { "\"@@\($0)\""}.joined(separator: ",\n")
+
+      let buildFileContents = """
+      load("@periphery//bazel:defs.bzl", "periphery_scan")
+
+      periphery_scan(
+        name = "scan",
+        testonly = True,
+        config = "\(FilePath.makeAbsolute(config))",
+        periphery_binary = "\(executablePath)",
+        visibility = [
+          "@periphery//bazel:generated"
+        ],
+        deps = [
+          \(deps)
+        ],
+      )
+      """
+
+      try buildFileContents.write(to: buildFilePath.url, atomically: true, encoding: .utf8)
+
+      let task = Process()
+      // TODO: Get bazel bin path
+      task.launchPath = "/opt/homebrew/bin/bazel"
+      task.arguments = ["run", "@periphery//bazel:scan"]
+      try task.run()
+      task.waitUntilExit()
+    }
+}

Sources/Frontend/main.swift

@@ -7,7 +7,13 @@ Logger.configureBuffering()
 struct PeripheryCommand: FrontendCommand {
     static let configuration = CommandConfiguration(
         commandName: "periphery",
-        subcommands: [ScanCommand.self, CheckUpdateCommand.self, ClearCacheCommand.self, VersionCommand.self]
+        subcommands: [
+          ScanCommand.self,
+          BazelScanCommand.self,
+          CheckUpdateCommand.self,
+          ClearCacheCommand.self,
+          VersionCommand.self
+        ]
     )
 }
 

Sources/Shared/Shell.swift

@@ -79,7 +79,7 @@ open class Shell {
                 result[pair.0] = pair.1
             }
 
-        let preservedKeys = ["PATH", "DEVELOPER_DIR"]
+        let preservedKeys = ["PATH", "DEVELOPER_DIR", "SSH_AUTH_SOCK"]
         preservedKeys.forEach { key in
             if let value = environment[key] {
                 newEnv[key] = value

bazel/BUILD

@@ -0,0 +1,20 @@
+package_group(
+    name = "generated",
+    includes = [
+      "@periphery_generated//:package_group"
+    ],
+    packages = [ # this is incorrect
+      "//...",
+    ]
+)
+
+genrule(
+  name = "scan",
+  testonly = True,
+  srcs = [
+    "@periphery_generated//generated:scan"
+  ],
+  cmd = "",
+  outs = ["scan.sh"],
+  executable = True
+)

bazel/defs.bzl

@@ -0,0 +1,60 @@
+def _get_template_substitutions(*, periphery_binary, config_path):
+    """Returns the template substitutions for this executable."""
+    subs = {
+        "periphery_binary": periphery_binary,
+        "config_path": config_path,
+    }
+    return {"%(" + k + ")s": subs[k] for k in subs}
+
+def _periphery_scan_impl(ctx):
+  print(ctx.attr.config)
+  print(ctx.attr.periphery_binary)
+  print(ctx.file._template)
+
+  # runfiles = ctx.runfiles(
+  #     files = source_files + indexstore_files + indexstores + [indexstores_file, file_targets_file, filter_files_file, ctx.executable._periphery, ctx.file._config],
+  # )
+
+  ctx.actions.expand_template(
+    template = ctx.file._template,
+    output = ctx.outputs.scan,
+    substitutions = _get_template_substitutions(
+        periphery_binary = ctx.attr.periphery_binary,
+        config_path = ctx.attr.config,
+    ),
+  )
+
+  return DefaultInfo(
+      executable = ctx.outputs.scan,
+      files = depset(
+          [ctx.outputs.scan],
+      ),
+  )
+
+periphery_scan = rule(
+    attrs = {
+        "deps": attr.label_list(mandatory = True),
+        "config": attr.string(),
+        "periphery_binary": attr.string(),
+        "_template": attr.label(
+            allow_single_file = True,
+            default = "@periphery//bazel/internal:scan_template.sh",
+        ),
+    },
+    outputs = {
+      "scan": "scan.sh",
+    },
+    implementation = _periphery_scan_impl,
+    executable = True,
+)
+
+def _foo(ctx):
+  print("foo")
+
+generated_periphery_scan = rule(
+  attrs = {
+    "deps": attr.label_list(mandatory = True),
+  },
+  implementation = _foo,
+  executable = True,
+)

bazel/extensions.bzl

@@ -0,0 +1,23 @@
+def _generated_files_repo_impl(repository_ctx):
+    repository_ctx.file(
+        "BUILD",
+        content = """
+package_group(
+    name = "package_group",
+    packages = ["//..."],
+)
+""",
+    )
+
+    # TODO: output_base_hash like rules_xcodeproj?
+    # TODO: scoped by project?
+    repository_ctx.symlink(
+        "/var/tmp/periphery_bazel/generated/BUILD",
+        "generated/BUILD",
+    )
+
+generated_files_repo = repository_rule(
+    implementation = _generated_files_repo_impl,
+)
+
+internal = module_extension(implementation = lambda _: generated_files_repo(name = "periphery_generated"))

bazel/internal/BUILD

@@ -0,0 +1,3 @@
+exports_files([
+  "scan_template.sh"
+])

bazel/internal/scan_template.sh

@@ -0,0 +1 @@
+echo "Hello from scan_template.sh"