Stop relying on target.kind in mixed builds.

target.kind was a field that existed for only a few months, and have
been removed from Bazel. This is needed to update to a newer Bazel version.

Also, this reverts filegroups to be queried for a specific arch again,
but leaving file targets in the common arch (which is correct, anyway).

Fixes: b/199363072
Test: mixed_libc
Test: presubmits
Change-Id: I3b8e5c43a39516d977d327a44a75750b2f251be3

android/bazel_handler.go

@@ -587,13 +587,11 @@ def %s(target):
 %s
 
 def get_arch(target):
-  # TODO(b/199363072): filegroups and file targets aren't associated with any
-  # specific platform architecture in mixed builds. This is consistent with how
-  # Soong treats filegroups, but it may not be the case with manually-written
-  # filegroup BUILD targets.
-  if target.kind in ["filegroup", ""]:
-    return "common"
   buildoptions = build_options(target)
+  if buildoptions == None:
+    # File targets do not have buildoptions. File targets aren't associated with
+    #  any specific platform architecture in mixed builds.
+    return "common"
   platforms = build_options(target)["//command_line_option:platforms"]
   if len(platforms) != 1:
     # An individual configured target should have only one platform architecture.

android/filegroup.go

@@ -112,15 +112,22 @@ func FileGroupFactory() Module {
 	return module
 }
 
-func (fg *fileGroup) GenerateBazelBuildActions(ctx ModuleContext) bool {
+func (fg *fileGroup) maybeGenerateBazelBuildActions(ctx ModuleContext) {
 	if !fg.MixedBuildsEnabled(ctx) {
-		return false
+		return
+	}
+
+	archVariant := ctx.Arch().ArchType
+	if len(fg.Srcs()) == 1 && fg.Srcs()[0].Base() == fg.Name() {
+		// This will be a regular file target, not filegroup, in Bazel.
+		// See FilegroupBp2Build for more information.
+		archVariant = Common
 	}
 
 	bazelCtx := ctx.Config().BazelContext
-	filePaths, ok := bazelCtx.GetOutputFiles(fg.GetBazelLabel(ctx, fg), Common)
+	filePaths, ok := bazelCtx.GetOutputFiles(fg.GetBazelLabel(ctx, fg), archVariant)
 	if !ok {
-		return false
+		return
 	}
 
 	bazelOuts := make(Paths, 0, len(filePaths))
@@ -130,19 +137,15 @@ func (fg *fileGroup) GenerateBazelBuildActions(ctx ModuleContext) bool {
 	}
 
 	fg.srcs = bazelOuts
-
-	return true
 }
 
 func (fg *fileGroup) GenerateAndroidBuildActions(ctx ModuleContext) {
-	if fg.GenerateBazelBuildActions(ctx) {
-		return
-	}
-
 	fg.srcs = PathsForModuleSrcExcludes(ctx, fg.properties.Srcs, fg.properties.Exclude_srcs)
 	if fg.properties.Path != nil {
 		fg.srcs = PathsWithModuleSrcSubDir(ctx, fg.srcs, String(fg.properties.Path))
 	}
+
+	fg.maybeGenerateBazelBuildActions(ctx)
 }
 
 func (fg *fileGroup) Srcs() Paths {