Add prelim macro tracker [WIP]

rules/scala/macros/BUILD

@@ -0,0 +1,33 @@
+load("//rules:scala.bzl",
+        "annex_scala_library",
+        "annex_scala_binary")
+
+annex_scala_library(
+    name = "macro-spoor-plugin",
+    srcs = glob(["**/*.scala"], exclude = ["**/*Test.scala"]),
+    scala = "@scala_annex_scala_2_12",
+    deps = [
+        "@scala_annex_scala_2_12_scala_compiler//jar",
+        "@scala_annex_scala_2_12_scala_reflect//jar",
+    ],
+    deps_used_whitelist = [        
+        "@scala_annex_scala_2_12_scala_reflect//jar",
+    ],
+    resources = ["scalac-plugin.xml"],
+    visibility = ["//visibility:public"],    
+)
+
+annex_scala_binary(
+    name = "macro-spoor-plugin-usage",
+    srcs = glob(["**/*Test.scala"]),
+    scala = "@scala_annex_scala_2_12",
+    plugins = [
+        ":macro-spoor-plugin",        
+    ],
+    deps = [
+         "@scala_annex_com_lihaoyi_sourcecode_2_12",
+    ],
+    deps_used_whitelist = [        
+    ],
+    visibility = ["//visibility:public"],
+)

rules/scala/macros/MacroSpoorPlugin.scala

@@ -0,0 +1,59 @@
+package anx
+
+import scala.annotation.tailrec
+
+import scala.tools.nsc.{Global ⇒ NscGlobal}
+import scala.tools.nsc.plugins.{Plugin => NscPlugin, PluginComponent => NscPluginComponent}
+import scala.reflect.internal.Mode
+
+import scala.reflect.io.NoAbstractFile
+import scala.tools.nsc.io.AbstractFile
+
+import java.io.File
+
+final class MacroSpoorPlugin(val global: NscGlobal) extends NscPlugin {
+  import global._
+  import analyzer.{MacroPlugin => NscMacroPlugin, _}
+
+  override val name: String = "anx-macro-spoor"
+  override val description: String = "tracks which dependencies are needed to expand macros"
+  override val components: List[NscPluginComponent] = Nil
+
+  analyzer.addMacroPlugin(MacroPlugin)
+
+  private[this] object MacroPlugin extends NscMacroPlugin {
+    override def pluginsMacroRuntime(expandee: Tree): Option[MacroRuntime] = {
+      val macroDef = expandee.symbol
+      if (!fastTrack.contains(macroDef)) {
+        val file = classFile(macroDef.owner)
+        println("macro used file: " + file)
+      }
+      None
+    }
+  }
+
+  // copied from xsbt.LocateClassFile.classFile
+  @tailrec private[this] def classFile(sym: Symbol): Option[AbstractFile] = {
+    if (sym hasFlag scala.tools.nsc.symtab.Flags.PACKAGE) None
+    else {
+      val file = sym.associatedFile
+      if (file == NoAbstractFile) {
+        if (isTopLevelModule(sym)) {
+          val linked = sym.companionClass
+          if (linked == NoSymbol) None
+          else classFile(linked)
+        } else None
+      } else Some(file)
+    }
+  }
+
+  // copied from xsbt.ClassName.flatName
+  private[this] def flatname(s: Symbol, separator: Char) =
+    enteringPhase(currentRun.flattenPhase.next) { s fullName separator }
+
+  // copied from xsbt.ClassName.isTopLevelModule
+  private[this] def isTopLevelModule(sym: Symbol): Boolean =
+    enteringPhase(currentRun.picklerPhase.next) {
+      sym.isModuleClass && !sym.isImplClass && !sym.isNestedClass
+    }
+}

rules/scala/macros/Test.scala

@@ -0,0 +1,8 @@
+package doof
+
+object Foo {
+  def main(args: Array[String]): Unit = {
+    val line = implicitly[sourcecode.Line]
+    assert(line.value == 6)
+  }
+}

rules/scala/macros/scalac-plugin.xml

@@ -0,0 +1,4 @@
+<plugin>
+  <name>anx-macro-spoor</name>
+  <classname>anx.MacroSpoorPlugin</classname>
+</plugin>

rules/scala/private/core.bzl

@@ -84,7 +84,7 @@ def runner_common(ctx):
     ]
     compile_classpath = depset(order = "preorder", transitive = macro_classpath + [sdeps.transitive_compile_time_jars])
 
-    zipper_inputs, _, zipper_manifests = ctx.resolve_command(tools = [ctx.attr._zipper])
+    zipper_inputs, _, zipper_manifests = ctx.resolve_command(tools = [ctx.attr._zipper])    
 
     if ctx.files.resources:
         class_jar = ctx.actions.declare_file("{}/classes.zip".format(ctx.label.name))
@@ -94,8 +94,9 @@ def runner_common(ctx):
         args.add(resource_jar)
         args.set_param_file_format("multiline")
         args.use_param_file("@%s")
+        strip_prefix = ctx.label.package + "/" + ctx.attr.resource_strip_prefix
         for file in ctx.files.resources:
-            args.add("{}={}".format(_resource_path(file, ctx.attr.resource_strip_prefix), file.path))
+            args.add("{}={}".format(_resource_path(file, strip_prefix), file.path))
         ctx.actions.run(
             arguments = [args],
             executable = ctx.executable._zipper,
@@ -292,10 +293,13 @@ def _labeled_groups(labeled_jars_list):
     return [_labeled_group(labeled_jars) for labeled_jars in labeled_jars_list]
 
 def _resource_path(file, strip_prefix):
+    print(file.short_path)
+    print(strip_prefix)
     if strip_prefix:
         if not file.short_path.startswith(strip_prefix):
-            fail("{} does not have prefix {}".format(file.short_path, strip_prefix))
-        return file.short_path[len(strip_prefix) + 1 - int(file.short_path.endswith("/")):]
+            fail("{} does not have prefix {}".format(file.short_path, strip_prefix))        
+        return file.short_path[len(strip_prefix):]
+    # todo: consider removing custom automatic handling?
     conventional = [
         "src/main/resources/",
         "src/test/resources/",