From ec8593dfc6ca9224ff42e0e64fa00b8afa7ba27f Mon Sep 17 00:00:00 2001
From: arunkumar9t2 <arunk.beece@gmail.com>
Date: Wed, 10 Aug 2022 22:43:47 +0800
Subject: [PATCH] Disable header compilation for r-classes

---
 tools/build_config/build_config.bzl   | 23 ++++++++---------------
 tools/databinding/databinding.bzl     |  9 ++++++++-
 tools/java/BUILD.bazel                |  0
 tools/java/java_library_no_header.bzl | 26 ++++++++++++++++++++++++++
 4 files changed, 42 insertions(+), 16 deletions(-)
 create mode 100644 tools/java/BUILD.bazel
 create mode 100644 tools/java/java_library_no_header.bzl

diff --git a/tools/build_config/build_config.bzl b/tools/build_config/build_config.bzl
index e2b42a76..86bcb288 100644
--- a/tools/build_config/build_config.bzl
+++ b/tools/build_config/build_config.bzl
@@ -51,7 +51,7 @@ def build_config(
         booleans = {},
         ints = {},
         longs = {}):
-    """Generates a Jar file containing BuildConfig class just like AGP.
+    """Generates a kt_jvm_library target containing build config fields just like AGP.
 
     Usage:
     Add the field variables in the relevant dicts like (strings, booleans etc) and add a dependency
@@ -68,10 +68,7 @@ def build_config(
     """
 
     build_config = "BuildConfig"
-    build_config_file_path = "$(RULEDIR)/{}.kt".format(build_config)
-
-    # Uses srcjar so that the generated .kt file can be compiled to class file via kt_jvm_library
-    build_config_jar = name + ".srcjar"
+    build_config_file_path = "src/main/%s/%s.kt" % (name, build_config)
 
     strings_statements = _build_statement(
         _STRING_TYPE,
@@ -87,10 +84,9 @@ def build_config(
     ints_statements = _build_statement(_INT_TYPE, ints, False)
     longs_statements = _build_statement(_LONG_TYPE, longs, False)
 
-    # Cmd for genrule. Generates BuildConfig.kt and packages it to a Java jar file in the build
-    # directory
+    # Cmd for genrule. Generates BuildConfig.
     cmd = """
-cat << EOF > {build_config_file_path}
+cat << EOF > $@
 /**
  * Generated file do not modify
  */
@@ -102,9 +98,7 @@ object {build_config} {{
     {ints_statements}
     {longs_statements}
 }}
-EOF
-$(location @bazel_tools//tools/zip:zipper) c $@ {build_config_file_path}
-""".format(
+EOF""".format(
         build_config = build_config,
         build_config_file_path = build_config_file_path,
         package_name = package_name,
@@ -115,14 +109,13 @@ $(location @bazel_tools//tools/zip:zipper) c $@ {build_config_file_path}
     )
 
     native.genrule(
-        name = "_" + name,
-        outs = [build_config_jar],
+        name = "_%s_gen" % name,
+        outs = [build_config_file_path],
         cmd = cmd,
         message = "Generating %s's build config class" % (native.package_name()),
-        tools = ["@bazel_tools//tools/zip:zipper"],
     )
 
     kt_jvm_library(
         name = name,
-        srcs = [build_config_jar],
+        srcs = [build_config_file_path],
     )
diff --git a/tools/databinding/databinding.bzl b/tools/databinding/databinding.bzl
index 870b5ddc..2c83f36a 100644
--- a/tools/databinding/databinding.bzl
+++ b/tools/databinding/databinding.bzl
@@ -1,6 +1,7 @@
 load("@io_bazel_rules_kotlin//kotlin:kotlin.bzl", "kt_android_library")
 load("@io_bazel_rules_kotlin//kotlin:jvm.bzl", "kt_jvm_library")
 load(":databinding_stubs.bzl", "databinding_stubs")
+load("@grab_bazel_common//tools/java:java_library_no_header.bzl", "java_library_no_header")
 # load(":databinding_aar.bzl", "databinding_aar")
 
 # TODO(arun) Replace with configurable maven targets
@@ -95,6 +96,12 @@ def kt_db_android_library(
         neverlink = 1,  # Use the R classes only for compiling and not at runtime.
     )
 
+    r_classes_no_header = name + "-r-classes-no-header"
+    java_library_no_header(
+        name = r_classes_no_header,
+        dep = ":" + r_classes,
+    )
+
     # Create an intermediate target for compiling all Kotlin classes used in Databinding
     kotlin_target = name + "-kotlin"
     kotlin_targets = []
@@ -114,7 +121,7 @@ def kt_db_android_library(
             name = kotlin_target,
             srcs = srcs + [binding_classes_sources],
             plugins = plugins,
-            deps = deps + _DATABINDING_DEPS + [r_classes] + [
+            deps = deps + _DATABINDING_DEPS + [r_classes_no_header] + [
                 "@grab_bazel_common//tools/binding-adapter-bridge:binding-adapter-bridge",
                 "@grab_bazel_common//tools/android:android_sdk",
             ],
diff --git a/tools/java/BUILD.bazel b/tools/java/BUILD.bazel
new file mode 100644
index 00000000..e69de29b
diff --git a/tools/java/java_library_no_header.bzl b/tools/java/java_library_no_header.bzl
new file mode 100644
index 00000000..ed507f24
--- /dev/null
+++ b/tools/java/java_library_no_header.bzl
@@ -0,0 +1,26 @@
+def _java_header_compilation_transition(settings, attr):
+    _ignore = (settings, attr)
+    return {"//command_line_option:java_header_compilation": "False"}
+
+java_header_compilation_transition = transition(
+    implementation = _java_header_compilation_transition,
+    inputs = [],
+    outputs = ["//command_line_option:java_header_compilation"],
+)
+
+def _java_library_without_header_compilation(ctx):
+    return [java_common.merge([d[JavaInfo] for d in ctx.attr.dep])]
+
+java_library_no_header = rule(
+    implementation = _java_library_without_header_compilation,
+    attrs = {
+        "dep": attr.label(
+            providers = [JavaInfo],
+            mandatory = True,
+            cfg = java_header_compilation_transition,
+        ),
+        "_allowlist_function_transition": attr.label(
+            default = "@bazel_tools//tools/allowlists/function_transition_allowlist",
+        ),
+    },
+)