CMake build: Change how third party libraries are included
- Always use dir_pw_third_party_nanopb as a path.
- Improve error messages when building Nanopb protos without
dir_pw_third_party_nanopb set.
- Specify python3 instead of python in case the build isn't run in a
Python 3 virtual environment.
Change-Id: Id8ca6f7f944348803c0275883fc7125c465235fd
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/38400
Reviewed-by: Keir Mierle <keir@google.com>
Reviewed-by: Alexei Frolov <frolv@google.com>
Pigweed-Auto-Submit: Wyatt Hepler <hepler@google.com>
Commit-Queue: Auto-Submit <auto-submit@pigweed.google.com.iam.gserviceaccount.com>
diff --git a/pw_build/docs.rst b/pw_build/docs.rst
index 96e7a37..6fff0e4 100644
--- a/pw_build/docs.rst
+++ b/pw_build/docs.rst
@@ -461,17 +461,14 @@
---------------------
The CMake build includes third-party libraries similarly to the GN build. A
``dir_pw_third_party_<library>`` cache variable is defined for each third-party
-dependency. This variable can have one of three values:
+dependency. The variable must be set to the absolute path of the library in
+order to use it. If the variable is empty
+(``if("${dir_pw_third_party_<library>}" STREQUAL "")``), the dependency is not
+available.
-* ``""`` (empty) -- the dependency is not available
-* ``PRESENT`` -- the dependency is available and is already included in the
- build
-* ``</path/to/the/dependency>`` -- the dependency is available and will be
- automatically imported from this path using ``add_subdirectory``.
-
-If the variable is empty (``if("${dir_pw_third_party_<library>}" STREQUAL
-"")``), the dependency is not available. Otherwise, it is available and
-libraries declared by it can be referenced.
+Third-party dependencies are not automatically added to the build. They can be
+manually added with ``add_subdirectory`` or by setting the
+``pw_third_party_<library>_ADD_SUBDIRECTORY`` option to ``ON``.
Third party variables are set like any other cache global variable in CMake. It
is recommended to set these in one of the following ways:
@@ -481,7 +478,7 @@
.. code-block:: cmake
- set(dir_pw_third_party_nanopb PRESENT CACHE STRING "" FORCE)
+ set(dir_pw_third_party_nanopb ${CMAKE_CURRENT_SOURCE_DIR}/external/nanopb CACHE PATH "" FORCE)
* Set the variable at the command line with the ``-D`` option.
diff --git a/pw_presubmit/py/pw_presubmit/pigweed_presubmit.py b/pw_presubmit/py/pw_presubmit/pigweed_presubmit.py
index a0ec61f..989711c 100755
--- a/pw_presubmit/py/pw_presubmit/pigweed_presubmit.py
+++ b/pw_presubmit/py/pw_presubmit/pigweed_presubmit.py
@@ -200,6 +200,7 @@
f'-DCMAKE_TOOLCHAIN_FILE={toolchain}',
'-DCMAKE_EXPORT_COMPILE_COMMANDS=1',
f'-Ddir_pw_third_party_nanopb={ctx.package_root / "nanopb"}',
+ '-Dpw_third_party_nanopb_ADD_SUBDIRECTORY=ON',
env=build.env_with_clang_vars())
diff --git a/pw_protobuf_compiler/proto.cmake b/pw_protobuf_compiler/proto.cmake
index 60b146b..6d39633 100644
--- a/pw_protobuf_compiler/proto.cmake
+++ b/pw_protobuf_compiler/proto.cmake
@@ -79,7 +79,7 @@
add_custom_command(
COMMAND
- python
+ python3
"$ENV{PW_ROOT}/pw_build/py/pw_build/mirror_tree.py"
--source-root "${arg_STRIP_PREFIX}"
--directory "${out_dir}/sources/${arg_PREFIX}"
@@ -141,7 +141,7 @@
set(script "$ENV{PW_ROOT}/pw_protobuf_compiler/py/pw_protobuf_compiler/generate_protos.py")
add_custom_command(
COMMAND
- python
+ python3
"${script}"
--language "${LANGUAGE}"
--plugin-path "${PLUGIN}"
@@ -213,20 +213,32 @@
function(_pw_nanopb_library NAME SOURCES INPUTS DEPS INCLUDE_FILE OUT_DIR)
list(TRANSFORM DEPS APPEND .nanopb)
- set(nanopb_dir "$<TARGET_PROPERTY:$<IF:$<TARGET_EXISTS:protobuf-nanopb-static>,protobuf-nanopb-static,pw_build.empty>,SOURCE_DIR>")
- set(nanopb_plugin
- "$<IF:$<TARGET_EXISTS:protobuf-nanopb-static>,${nanopb_dir}/generator/protoc-gen-nanopb,COULD_NOT_FIND_protobuf-nanopb-static_TARGET_PLEASE_SET_UP_NANOPB>")
-
- _pw_generate_protos("${NAME}.generate.nanopb"
- nanopb
- "${nanopb_plugin}"
- ".pb.h;.pb.c"
- "${INCLUDE_FILE}"
- "${OUT_DIR}"
- "${SOURCES}"
- "${INPUTS}"
- "${DEPS}"
- )
+ if("${dir_pw_third_party_nanopb}" STREQUAL "")
+ add_custom_target("${NAME}.generate.nanopb"
+ cmake -E echo
+ ERROR: Attempting to use pw_proto_library, but
+ dir_pw_third_party_nanopb is not set. Set dir_pw_third_party_nanopb
+ to the path to the Nanopb repository.
+ COMMAND
+ cmake -E false
+ DEPENDS
+ ${DEPS}
+ SOURCES
+ ${SOURCES}
+ )
+ set(generated_outputs $<TARGET_PROPERTY:pw_build.empty,SOURCES>)
+ else()
+ _pw_generate_protos("${NAME}.generate.nanopb"
+ nanopb
+ "${dir_pw_third_party_nanopb}/generator/protoc-gen-nanopb"
+ ".pb.h;.pb.c"
+ "${INCLUDE_FILE}"
+ "${OUT_DIR}"
+ "${SOURCES}"
+ "${INPUTS}"
+ "${DEPS}"
+ )
+ endif()
# Create the library with the generated source files.
add_library("${NAME}.nanopb" EXCLUDE_FROM_ALL ${generated_outputs})
diff --git a/third_party/nanopb/CMakeLists.txt b/third_party/nanopb/CMakeLists.txt
index 1341403..7b5745e 100644
--- a/third_party/nanopb/CMakeLists.txt
+++ b/third_party/nanopb/CMakeLists.txt
@@ -12,19 +12,22 @@
# License for the specific language governing permissions and limitations under
# the License.
-set(dir_pw_third_party_nanopb "" CACHE PATH
- "Path to a Nanopb installation to import. Set to PRESENT if Nanopb is already present in the build."
-)
+set(dir_pw_third_party_nanopb "" CACHE PATH "Path to the Nanopb installation.")
+option(pw_third_party_nanopb_ADD_SUBDIRECTORY
+ "Whether to add the dir_pw_third_party_nanopb subdirectory" OFF)
if("${dir_pw_third_party_nanopb}" STREQUAL "")
return()
-elseif(NOT "${dir_pw_third_party_nanopb}" STREQUAL PRESENT)
+elseif(pw_third_party_nanopb_ADD_SUBDIRECTORY)
add_subdirectory("${dir_pw_third_party_nanopb}" third_party/nanopb)
endif()
+set(nanopb_main_library
+ $<IF:$<TARGET_EXISTS:protobuf-nanopb-static>,protobuf-nanopb-static,protobuf-nanopb>)
+
add_library(pw_third_party.nanopb INTERFACE)
-target_link_libraries(pw_third_party.nanopb INTERFACE protobuf-nanopb-static)
+target_link_libraries(pw_third_party.nanopb INTERFACE "${nanopb_main_library}")
target_include_directories(pw_third_party.nanopb
INTERFACE
- $<TARGET_PROPERTY:protobuf-nanopb-static,SOURCE_DIR>
+ "${dir_pw_third_party_nanopb}"
)
