bazel: Move stm32f429i defines into cc_library

Change-Id: Ibe510a7d06e57679456bdd04171d469b09b4c2a9
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/234913
Commit-Queue: Taylor Cramer <cramertj@google.com>
Docs-Not-Needed: Taylor Cramer <cramertj@google.com>
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
Reviewed-by: Ted Pudlik <tpudlik@google.com>

.bazelrc

@@ -154,12 +154,6 @@ build:stm32f429i_baremetal --platforms=//targets/stm32f429i_disc1:platform
 # Config for the stm32f429i_disc1_stm32cube freertos platform.
 #
 build:stm32f429i_freertos --platforms=//targets/stm32f429i_disc1_stm32cube:platform
-# This should be moved to platform-based flags once 
-# https://github.com/bazelbuild/bazel/issues/22453
-# is fixed.
-build:stm32f429i_freertos --copt="-DSTM32CUBE_HEADER=\"stm32f4xx.h\""
-build:stm32f429i_freertos --copt="-DSTM32F429xx"
-
 
 # Config for the lm3s6965evb platform, used to build pw_rust/examples.
 build:lm3s6965evb --platforms=//pw_build/platforms:lm3s6965evb

pw_stm32cube_build/docs.rst

@@ -267,23 +267,23 @@ family. To do so,
 1.  Add the appropriate repositories to your WORKSPACE under different names,
     eg. ``@stm32f4xx_hal_driver`` and ``@stm32h7xx_hal_driver``.
 2.  Set the corresponding :ref:`module-pw_stm32cube_build-bazel-label-flags` as
-    part of the platform configuration for your embedded target platforms.
-    Currently, the best way to do this is via a `bazelrc config
-    <https://bazel.build/run/bazelrc#config>`_, which would look like this:
+    part of the platform definition for your embedded target platforms.
 
-    .. code-block::
-
-       build:stm32f429i --platforms=//targets/stm32f429i_disc1_stm32cube:platform
-       build:stm32f429i --@pigweed//third_party/stm32cube:hal_driver=@stm32f4xx_hal_driver//:hal_driver
-       build:stm32f429i --@stm32f4xx_hal_driver//:hal_config=//your/repo:hal_config
-       build:stm32f429i --@stm32f4xx_hal_driver//:cmsis_device=@cmsis_device_f4//:cmsis_device
-       build:stm32f429i --@stm32f4xx_hal_driver//:cmsis_core=@cmsis_core_f4
-       build:stm32f429i --@stm32f4xx_hal_driver//:cmsis_init=@cmsis_device_f4//:default_cmsis_init
+.. code-block:: text
 
-    However, once `platform-based flags
-    <https://github.com/bazelbuild/proposals/blob/main/designs/2023-06-08-platform-based-flags.md>`_
-    are implemented in Bazel, it will be possible to set these flags directly
-    in the platform definition.
+   platform(
+     name = "...",
+     ...
+     flags = flags_from_dict({
+       ...
+       "@cmsis_core//:cc_defines": ":<your cc_defines target>",
+       "@stm32f4xx_hal_driver//:hal_config": "//targets/stm32f429i_disc1_stm32cube:hal_config",
+       "@pigweed//third_party/stm32cube:hal_driver": "@stm32f4xx_hal_driver//:hal_driver",
+       "@stm32f4xx_hal_driver//:cmsis_device": "@cmsis_device_f4//:cmsis_device",
+       "@stm32f4xx_hal_driver//:cmsis_init": "@cmsis_device_f4//:default_cmsis_init",
+       "@cmsis_device_f4//:cmsis_core": "@cmsis_core",
+     }),
+   )
 
 .. [#] Although CMSIS core is shared by all MCU families, different CMSIS
    device repositories may not be compatible with the same version of CMSIS
@@ -300,8 +300,9 @@ Upstream Pigweed modules that depend on the STM32Cube HAL, like
 header ``stm32cube/stm32cube.h``. This header expects the family to be set
 through a define of ``STM32CUBE_HEADER``. So, to use these Pigweed modules, you
 need to set that define to the correct value (e.g., ``\"stm32f4xx.h\"``; note
-the backslashes) as part of your build. This is most conveniently done through
-``copts`` associated with the target platform.
+the backslashes) as part of your build. This is most conveniently done via the
+``defines`` attribute of a ``cc_library`` target which is then set as the
+value of the ``@cmsis_core//:cc_defines`` label flag.
 
 .. _module-pw_stm32cube_build-bazel-label-flags:
 
@@ -320,6 +321,11 @@ Points to the ``cc_library`` target providing a header with the HAL
 configuration. Note that this header needs an appropriate, family-specific name
 (e.g., ``stm32f4xx_hal_conf.h`` for the F4 family).
 
+``@cmsis_core//:cc_defines``
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+This label flag should point to a `cc_library` target which adds `define`
+entries for `STM32CUBE_HEADER` and the `STM32....` family (e.g. `STM32F429xx`).
+
 ``@cmsis_device//:cmsis_core``
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 This label flag should point to the repository containing the CMSIS core build

targets/stm32f429i_disc1_stm32cube/BUILD.bazel

@@ -60,6 +60,7 @@ platform(
         "@rust_crates//:no_std",
     ],
     flags = flags_from_dict(FREERTOS_FLAGS | {
+        "@cmsis_core//:cc_defines": ":cc_defines",
         "@pigweed//pw_assert:check_backend": "//pw_assert_basic",
         "@pigweed//pw_assert:check_backend_impl": "//pw_assert_basic:impl",
         "@pigweed//pw_boot:backend": "//pw_boot_cortex_m",
@@ -72,14 +73,14 @@ platform(
         "@pigweed//pw_unit_test:main": "//targets/stm32f429i_disc1_stm32cube:unit_test_app",
         "@stm32f4xx_hal_driver//:hal_config": "//targets/stm32f429i_disc1_stm32cube:hal_config",
     }),
-    # These flags should be added once
-    # https://github.com/bazelbuild/bazel/issues/22453
-    # is fixed.
-    #
-    # + [
-    #   "--copt=\"-DSTM32CUBE_HEADER=\\\"stm32f4xx.h\\\"\"",
-    #   "--copt=\"-DSTM32F429xx\"",
-    # ],
+)
+
+cc_library(
+    name = "cc_defines",
+    defines = [
+        "STM32CUBE_HEADER=\\\"stm32f4xx.h\\\"",
+        "STM32F429xx",
+    ],
 )
 
 cc_library(

third_party/stm32cube/cmsis_core.BUILD.bazel

@@ -27,4 +27,12 @@ cc_library(
         "Include",
         "Include/DSP/Include",
     ],
+    deps = [
+        ":cc_defines",
+    ],
+)
+
+label_flag(
+    name = "cc_defines",
+    build_setting_default = "@pigweed//pw_build:empty_cc_library",
 )