Make bp2build be more correct.

It now handles adding .bp files and changing globs.

In order to do this, depfiles are now written separately from RunBlueprint.

This is necessary due to the confluence of a number of seemingly
unrelated factors:

1. The glob filelist dependencies are discovered in globSingleton
2. Singletons need to be registered because otherwise singleton module
   types panic
3. Singletons don't work because they require mutators bp2build does not
   run

Due to (1), we would need to run the glob singleton. However, due to (2)
and (3), we can't run singletons and have to run Blueprint with
StopBeforeGeneratingBuildActions, which is when the build actions
writing glob files would be generated. So what happens is:

1. When bp2build is run, the glob singleton is disabled
2. At the end of bp2build, the list of glob files is artifically added
   to the depfile of the workspace marker file
3. When build.ninja is generated, the Ninja file containing the glob
   list file is written by the now-active glob singleton

Test: Presubmits.
Change-Id: I3c5898d8c57c554a93520276c64a952afc912dbe

tests/bootstrap_test.sh

@@ -429,12 +429,47 @@ function test_integrated_bp2build_smoke {
   setup
   INTEGRATED_BP2BUILD=1 run_soong
   if [[ ! -e out/soong/.bootstrap/bp2build_workspace_marker ]]; then
-    fail "b2build marker file not created"
+    fail "bp2build marker file not created"
+  fi
+}
+
+function test_integrated_bp2build_add_android_bp {
+  setup
+
+  mkdir -p a
+  touch a/a.txt
+  cat > a/Android.bp <<'EOF'
+filegroup {
+  name: "a",
+  srcs: ["a.txt"],
+  bazel_module: { bp2build_available: true },
+}
+EOF
+
+  INTEGRATED_BP2BUILD=1 run_soong
+  if [[ ! -e out/soong/bp2build/a/BUILD ]]; then
+    fail "a/BUILD not created";
+  fi
+
+  mkdir -p b
+  touch b/b.txt
+  cat > b/Android.bp <<'EOF'
+filegroup {
+  name: "b",
+  srcs: ["b.txt"],
+  bazel_module: { bp2build_available: true },
+}
+EOF
+
+  INTEGRATED_BP2BUILD=1 run_soong
+  if [[ ! -e out/soong/bp2build/b/BUILD ]]; then
+    fail "b/BUILD not created";
   fi
 }
 
 function test_integrated_bp2build_null_build {
   setup
+
   INTEGRATED_BP2BUILD=1 run_soong
   local mtime1=$(stat -c "%y" out/soong/build.ninja)
 
@@ -446,6 +481,27 @@ function test_integrated_bp2build_null_build {
   fi
 }
 
+function test_integrated_bp2build_add_to_glob {
+  setup
+
+  mkdir -p a
+  touch a/a1.txt
+  cat > a/Android.bp <<'EOF'
+filegroup {
+  name: "a",
+  srcs: ["*.txt"],
+  bazel_module: { bp2build_available: true },
+}
+EOF
+
+  INTEGRATED_BP2BUILD=1 run_soong
+  grep -q a1.txt out/soong/bp2build/a/BUILD || fail "a1.txt not in BUILD file"
+
+  touch a/a2.txt
+  INTEGRATED_BP2BUILD=1 run_soong
+  grep -q a2.txt out/soong/bp2build/a/BUILD || fail "a2.txt not in BUILD file"
+}
+
 function test_dump_json_module_graph() {
   setup
   SOONG_DUMP_JSON_MODULE_GRAPH="$MOCK_TOP/modules.json" run_soong
@@ -468,3 +524,4 @@ test_soong_build_rerun_iff_environment_changes
 test_dump_json_module_graph
 test_integrated_bp2build_smoke
 test_integrated_bp2build_null_build
+test_integrated_bp2build_add_to_glob