kleaf: Do not include GKI modules in default output of //common:kernel_aarch64.

This change adds the `module_implicit_outs` mechanism
to kernel_build that acts like `module_outs` but not
added to default info (like implicit_outs). This allows
us to exclude GKI modules from //common:kernel_aarch64
DefaultInfo.

When a device kernel builds their own modules that
conflicts with the GKI modules (zram and zsmalloc
for android13-5.15), the dist target will produce a
warning about conflicting source files.

Hence, do not include zram and zsmalloc to the device
dist targets by default when they include "//common:kernel_aarch64"
only.

If they wish to include zram and zsmalloc in
the distribution on the android13-5.15 branch,
they may add the following to the
dist target:

  "//common:kernel_aarch64_modules",

or individual modules:

  "//common:kernel_aarch64/drivers/block/zram/zram.ko",
  "//common:kernel_aarch64/mm/zsmalloc.ko",

//common:kernel_aarch64_dist continues to include GKI
modules defined by the branch.

Bug: 244215515
Test: manual

Change-Id: Id1c9fd9e603e9b2946cd59c7fde14d11ef7dd8b2

5 files changed, 43 insertions, 13 deletions

diff --git a/kleaf/common_kernels.bzl b/kleaf/common_kernels.bzl
index 8aeb866..719716d 100644
--- a/kleaf/common_kernels.bzl
+++ b/kleaf/common_kernels.bzl
@@ -83,7 +83,7 @@ _KERNEL_BUILD_ABI_VALID_KEYS = [
     "kmi_symbol_list_strict_mode",
     "abi_definition",
     "kmi_enforced",
-    "module_outs",
+    "module_implicit_outs",
 ]
 
 # Valid configs of the value of the target_config argument in
@@ -191,6 +191,7 @@ def define_common_kernels(
       - `kernel_aarch64`
       - `kernel_aarch64_uapi_headers`
       - `kernel_aarch64_additional_artifacts`
+      - `kernel_aarch64_modules`
     - `kernel_aarch64_debug_dist`
       - `kernel_aarch64_debug`
     - `kernel_x86_64_sources`
@@ -290,7 +291,7 @@ def define_common_kernels(
         - `ADDITIONAL_KMI_SYMBOL_LISTS`
         - `TRIM_NONLISTED_KMI`
         - `KMI_SYMBOL_LIST_STRICT_MODE`
-        - `GKI_MODULES_LIST` (corresponds to [`kernel_build.module_outs`](#kernel_build-module_outs))
+        - `GKI_MODULES_LIST` (corresponds to [`kernel_build.module_implicit_outs`](#kernel_build-module_implicit_outs))
         - `BUILD_GKI_ARTIFACTS`
         - `BUILD_GKI_BOOT_IMG_SIZE` and `BUILD_GKI_BOOT_IMG_{COMPRESSION}_SIZE`
 
@@ -307,7 +308,7 @@ def define_common_kernels(
         - `additional_kmi_symbol_lists`
         - `trim_nonlisted_kmi`
         - `kmi_symbol_list_strict_mode`
-        - `module_outs` (corresponds to `GKI_MODULES_LIST`)
+        - `module_implicit_outs` (corresponds to `GKI_MODULES_LIST`)
 
         In addition, the values of `target_configs` may contain the following keys:
         - `build_gki_artifacts`
@@ -518,7 +519,7 @@ def define_common_kernels(
         kernel_modules_install(
             name = name + "_modules_install",
             # The GKI target does not have external modules. GKI modules goes
-            # into the in-tree kernel module list, aka kernel_build.module_outs.
+            # into the in-tree kernel module list, aka kernel_build.module_implicit_outs.
             # Hence, this is empty, and name + "_dist" does NOT include
             # name + "_modules_install".
             kernel_modules = [],
@@ -560,7 +561,16 @@ def define_common_kernels(
             output_group = "modules_staging_archive",
         )
 
-        # Everything in name + "_dist", minus UAPI headers & DDK, because
+        # All GKI modules
+        native.filegroup(
+            name = name + "_modules",
+            srcs = [
+                "{}/{}".format(name, module)
+                for module in (kernel_build_abi_kwargs["module_implicit_outs"] or [])
+            ],
+        )
+
+        # Everything in name + "_dist", minus UAPI headers & DDK & modules, because
         # device-specific external kernel modules may install different headers.
         native.filegroup(
             name = name + "_additional_artifacts",
@@ -591,6 +601,7 @@ def define_common_kernels(
             name + "_unstripped_modules_archive",
             name + "_additional_artifacts",
             name + "_ddk_artifacts",
+            name + "_modules",
             # BUILD_GKI_CERTIFICATION_TOOLS=1 for all kernel_build defined here.
             "//build/kernel:gki_certification_tools",
         ]
diff --git a/kleaf/docs/build_configs.md b/kleaf/docs/build_configs.md
index f41c8c9..4ec40a1 100644
--- a/kleaf/docs/build_configs.md
+++ b/kleaf/docs/build_configs.md
@@ -494,7 +494,7 @@ Reason: The Bazel build already sets the order of loading modules for you, and
 
 Not customizable in Bazel.
 
-Reason: This is set to a fixed value in the `module_outs` attribute of
+Reason: This is set to a fixed value in the `module_implicit_outs` attribute of
 `//common:kernel_aarch64`.
 
 See [documentation for all rules].
diff --git a/kleaf/docs/impl.md b/kleaf/docs/impl.md
index ef339ba..84aad56 100644
--- a/kleaf/docs/impl.md
+++ b/kleaf/docs/impl.md
@@ -220,6 +220,15 @@ that the outputs are analogous to those produced by `build/build.sh`:
   * `//common:kernel_aarch64`
   * `//common:kernel_aarch64_additional_artifacts`
 * UAPI headers, e.g. `//common:kernel_aarch64_uapi_headers`
+* GKI modules
+  * If you are using all GKI modules, add `//common:kernel_aarch64_modules`.
+  * If you are using part of the GKI modules, add them individually, e.g.:
+    * `//common:kernel_aarch64/drivers/block/zram/zram.ko`
+    * `//common:kernel_aarch64/mm/zsmalloc.ko`
+  * Modules from the device kernel build with the same name as GKI modules
+    (e.g. on android13-5.15, you have `zram.ko` in `kernel_build.module_outs`)
+    does not need to be specified, because `module_outs` are added to
+    distribution.
 
 Example for Pixel 2021 (see the `copy_to_dist_dir` target named `slider_dist`):
 
diff --git a/kleaf/impl/common_providers.bzl b/kleaf/impl/common_providers.bzl
index 45371f0..5dc7822 100644
--- a/kleaf/impl/common_providers.bzl
+++ b/kleaf/impl/common_providers.bzl
@@ -70,7 +70,7 @@ KernelBuildAbiInfo = provider(
     fields = {
         "trim_nonlisted_kmi": "Value of `trim_nonlisted_kmi` in [`kernel_build()`](#kernel_build).",
         "combined_abi_symbollist": "The **combined** `abi_symbollist` file from the `_kmi_symbol_list` rule, consist of the source `kmi_symbol_list` and `additional_kmi_symbol_lists`.",
-        "module_outs_file": "A file containing `[kernel_build.module_outs]`(#kernel_build-module_outs).",
+        "module_outs_file": "A file containing `[kernel_build.module_outs]`(#kernel_build-module_outs) and `[kernel_build.module_implicit_outs]`(#kernel_build-module_implicit_outs).",
     },
 )
 
@@ -78,7 +78,7 @@ KernelBuildInTreeModulesInfo = provider(
     doc = """A provider that specifies the expectations of a [`kernel_build`](#kernel_build) on its
 [`base_kernel`](#kernel_build-base_kernel) or [`base_kernel_for_module_outs`](#kernel_build-base_kernel_for_module_outs).""",
     fields = {
-        "module_outs_file": "A file containing `[kernel_build.module_outs]`(#kernel_build-module_outs).",
+        "module_outs_file": "A file containing `[kernel_build.module_outs]`(#kernel_build-module_outs) and `[kernel_build.module_implicit_outs]`(#kernel_build-module_implicit_outs).",
     },
 )
 
diff --git a/kleaf/impl/kernel_build.bzl b/kleaf/impl/kernel_build.bzl
index eb7e476..2c99b77 100644
--- a/kleaf/impl/kernel_build.bzl
+++ b/kleaf/impl/kernel_build.bzl
@@ -63,6 +63,7 @@ def kernel_build(
         srcs = None,
         module_outs = None,
         implicit_outs = None,
+        module_implicit_outs = None,
         generate_vmlinux_btf = None,
         deps = None,
         base_kernel = None,
@@ -245,6 +246,11 @@ def kernel_build(
         implicit_outs: Like `outs`, but not copied to the distribution directory.
 
           Labels are created for each item in `implicit_outs` as in `outs`.
+
+        module_implicit_outs: like `module_outs`, but not copied to the distribution directory.
+
+          Labels are created for each item in `module_implicit_outs` as in `outs`.
+
         kmi_symbol_list: A label referring to the main KMI symbol list file. See `additional_kmi_symbol_list`.
 
           This is the Bazel equivalent of `ADDTIONAL_KMI_SYMBOL_LISTS`.
@@ -405,6 +411,7 @@ def kernel_build(
         outs = kernel_utils.transform_kernel_build_outs(name, "outs", outs),
         module_outs = kernel_utils.transform_kernel_build_outs(name, "module_outs", module_outs),
         implicit_outs = kernel_utils.transform_kernel_build_outs(name, "implicit_outs", implicit_outs),
+        module_implicit_outs = kernel_utils.transform_kernel_build_outs(name, "module_implicit_outs", module_implicit_outs),
         internal_outs = kernel_utils.transform_kernel_build_outs(name, "internal_outs", _kernel_build_internal_outs),
         deps = deps,
         base_kernel = base_kernel,
@@ -426,6 +433,7 @@ def kernel_build(
         ("outs", outs),
         ("module_outs", module_outs),
         ("implicit_outs", implicit_outs),
+        ("module_implicit_outs", module_implicit_outs),
         # internal_outs are opaque to the user, hence we don't create a alias (filegroup) for them.
     ):
         if out_attr_val == None:
@@ -483,9 +491,10 @@ def kernel_build(
         target = name,
         **kwargs
     )
+
     kernel_module_test(
         name = name + "_modules_test",
-        modules = real_outs.get("module_outs"),
+        modules = (real_outs.get("module_outs") or []) + (real_outs.get("module_implicit_outs") or []),
         **kwargs
     )
 
@@ -551,15 +560,15 @@ def _kernel_build_impl(ctx):
     # => all_output_names = ["foo", "Module.symvers", ...]
     #    all_output_files = {"out": {"foo": File(...)}, "internal_outs": {"Module.symvers": File(...)}, ...}
     all_output_files = {}
-    for attr in ("outs", "module_outs", "implicit_outs", "internal_outs"):
+    for attr in ("outs", "module_outs", "implicit_outs", "module_implicit_outs", "internal_outs"):
         all_output_files[attr] = {name: ctx.actions.declare_file("{}/{}".format(ctx.label.name, name)) for name in getattr(ctx.attr, attr)}
     all_output_names_minus_modules = []
     for attr, d in all_output_files.items():
-        if attr != "module_outs":
+        if attr not in ("module_outs", "module_implicit_outs"):
             all_output_names_minus_modules += d.keys()
 
     # A file containing all module_outs
-    all_module_names = all_output_files["module_outs"].keys()
+    all_module_names = all_output_files["module_outs"].keys() + all_output_files["module_implicit_outs"].keys()
     all_module_names_file = ctx.actions.declare_file("{name}_all_module_names/{name}{suffix}".format(name = ctx.label.name, suffix = MODULE_OUTS_FILE_SUFFIX))
     ctx.actions.write(
         output = all_module_names_file,
@@ -848,6 +857,7 @@ _kernel_build = rule(
         "outs": attr.string_list(),
         "module_outs": attr.string_list(doc = "output *.ko files"),
         "internal_outs": attr.string_list(doc = "Like `outs`, but not in dist"),
+        "module_implicit_outs": attr.string_list(doc = "Like `module_outs`, but not in dist"),
         "implicit_outs": attr.string_list(doc = "Like `outs`, but not in dist"),
         "_check_declared_output_list": attr.label(
             allow_single_file = True,
@@ -867,7 +877,7 @@ _kernel_build = rule(
         ),
         "base_kernel_for_module_outs": attr.label(
             providers = [KernelBuildInTreeModulesInfo],
-            doc = "If set, use the `module_outs` of this label as an allowlist for modules in the staging directory. Otherwise use `base_kernel`.",
+            doc = "If set, use the `module_outs` and `module_implicit_outs` of this label as an allowlist for modules in the staging directory. Otherwise use `base_kernel`.",
         ),
         "kmi_symbol_list_strict_mode": attr.bool(),
         "raw_kmi_symbol_list": attr.label(