Add granular CMake targets with generate_cmake.py

CMakeLists.txt

@@ -4,13 +4,21 @@
 # This source code is licensed under the BSD-style license found in the
 # LICENSE file in the root directory of this source tree.
 
-cmake_minimum_required(VERSION 3.10)
+cmake_minimum_required(VERSION 3.13)
 include(CheckCXXCompilerFlag)
 
+# Allow cross-directory target_link_libraries
+# (required for deferred dependency resolution)
+cmake_policy(SET CMP0079 NEW)
+
 project(
   moxygen
 )
 
+# Set for FetchContent to skip find_package(moxygen)
+set(moxygen_SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}"
+  CACHE INTERNAL "moxygen source directory")
+
 # Needs 20 for co routines
 set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
@@ -47,15 +55,31 @@ set (DEPS_LIBRARIES_DIR ${MOXYGEN_FBCODE_ROOT}/_build/deps/lib)
 #
 # IMPORTANT: If you change this, make the analogous update in:
 #   cmake/moxygen-config.cmake.in
-find_package(folly REQUIRED)
-find_package(wangle REQUIRED)
-find_package(mvfst REQUIRED)
-find_package(proxygen REQUIRED)
+# If deps are being built from source (FetchContent), skip find_package
+if (NOT DEFINED folly_SOURCE_DIR)
+  find_package(folly REQUIRED)
+endif()
+if (NOT DEFINED fizz_SOURCE_DIR)
+  find_package(fizz REQUIRED)
+endif()
+if (NOT DEFINED mvfst_SOURCE_DIR)
+  find_package(mvfst REQUIRED)
+endif()
+if (NOT DEFINED proxygen_SOURCE_DIR)
+  find_package(proxygen REQUIRED)
+endif()
 find_package(Glog REQUIRED)
 add_compile_definitions(GLOG_USE_GLOG_EXPORT)
 find_package(gflags REQUIRED)
 find_package(Zstd REQUIRED)
 
+# Define BUILD_SAMPLES after find_package calls so it doesn't affect
+# proxygen's BUILD_SAMPLES option during config
+option(BUILD_SAMPLES
+  "If enabled, build moxygen sample executables and test tools."
+  ON
+)
+
 list(APPEND
   _MOXYGEN_COMMON_COMPILE_OPTIONS
   -Wall
@@ -92,9 +116,12 @@ if (COMPILER_HAS_W_UNUSED_VALUE)
 endif()
 
 include(MoxygenTest)
+include(MoxygenFunctions)
 
 add_subdirectory(moxygen)
 
+moxygen_resolve_deferred_dependencies()
+
 if (NOT DEFINED LIB_INSTALL_DIR)
     set(LIB_INSTALL_DIR "lib")
 endif()

cmake/MoxygenFunctions.cmake

@@ -0,0 +1,199 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the BSD-style license found in the
+# LICENSE file in the root directory of this source tree.
+
+# Allow cross-directory target_link_libraries
+cmake_policy(SET CMP0079 NEW)
+
+# Initialize global properties for tracking targets and deferred dependencies
+set_property(GLOBAL PROPERTY MOXYGEN_COMPONENT_TARGETS)
+set_property(GLOBAL PROPERTY MOXYGEN_DEFERRED_DEPS)
+
+# moxygen_add_library(<name>
+#   SRCS file1.cpp file2.cpp        # Source files
+#   DEPS internal_dep                # Private dependencies
+#   EXPORTED_DEPS Folly::folly       # Public dependencies (propagated)
+# )
+function(moxygen_add_library _target_name)
+  cmake_parse_arguments(
+    MOXYGEN_LIB
+    ""                              # Options (boolean flags)
+    ""                              # Single-value args
+    "SRCS;DEPS;EXPORTED_DEPS"       # Multi-value args
+    ${ARGN}
+  )
+
+  set(_sources ${MOXYGEN_LIB_SRCS})
+  if(NOT _sources)
+    # Legacy support: if no SRCS keyword, treat remaining args as sources
+    set(_sources ${MOXYGEN_LIB_UNPARSED_ARGUMENTS})
+  endif()
+
+  # Separate moxygen internal deps from external deps
+  set(_immediate_deps "")
+  set(_moxygen_deps "")
+  foreach(_dep IN LISTS MOXYGEN_LIB_EXPORTED_DEPS)
+    if(_dep MATCHES "^moxygen_")
+      list(APPEND _moxygen_deps ${_dep})
+    else()
+      list(APPEND _immediate_deps ${_dep})
+    endif()
+  endforeach()
+
+  set(_private_immediate "")
+  set(_private_moxygen "")
+  foreach(_dep IN LISTS MOXYGEN_LIB_DEPS)
+    if(_dep MATCHES "^moxygen_")
+      list(APPEND _private_moxygen ${_dep})
+    else()
+      list(APPEND _private_immediate ${_dep})
+    endif()
+  endforeach()
+
+  # Skip if no sources (header-only library)
+  list(LENGTH _sources _src_count)
+  if(_src_count EQUAL 0)
+    # Header-only: create INTERFACE library
+    add_library(${_target_name} INTERFACE)
+    target_include_directories(${_target_name}
+      INTERFACE
+        $<BUILD_INTERFACE:${MOXYGEN_FBCODE_ROOT}>
+        $<INSTALL_INTERFACE:include/>
+    )
+
+    # Link external deps immediately for INTERFACE libraries
+    if(_immediate_deps)
+      target_link_libraries(${_target_name} INTERFACE ${_immediate_deps})
+    endif()
+
+    # Defer moxygen internal deps for INTERFACE libraries
+    if(_moxygen_deps)
+      list(JOIN _moxygen_deps "," _deps_str)
+      set_property(GLOBAL APPEND PROPERTY MOXYGEN_DEFERRED_DEPS
+        "${_target_name}|INTERFACE|${_deps_str}"
+      )
+    endif()
+
+    install(TARGETS ${_target_name} EXPORT moxygen-exports)
+    add_library(moxygen::${_target_name} ALIAS ${_target_name})
+    return()
+  endif()
+
+  # Create STATIC library
+  add_library(${_target_name} STATIC ${_sources})
+
+  if(DEFINED PACKAGE_VERSION)
+    set_property(TARGET ${_target_name} PROPERTY VERSION ${PACKAGE_VERSION})
+  endif()
+
+  if(BUILD_SHARED_LIBS)
+    set_property(TARGET ${_target_name} PROPERTY POSITION_INDEPENDENT_CODE ON)
+  endif()
+
+  target_include_directories(${_target_name}
+    PUBLIC
+      $<BUILD_INTERFACE:${MOXYGEN_FBCODE_ROOT}>
+      $<INSTALL_INTERFACE:include/>
+  )
+
+  target_compile_options(${_target_name}
+    PRIVATE
+    ${_MOXYGEN_COMMON_COMPILE_OPTIONS}
+  )
+
+  target_compile_features(${_target_name} PUBLIC cxx_std_20)
+
+  # Link external deps immediately
+  if(_immediate_deps)
+    target_link_libraries(${_target_name} PUBLIC ${_immediate_deps})
+  endif()
+
+  # Defer moxygen internal deps
+  if(_moxygen_deps)
+    list(JOIN _moxygen_deps "," _deps_str)
+    set_property(GLOBAL APPEND PROPERTY MOXYGEN_DEFERRED_DEPS
+      "${_target_name}|PUBLIC|${_deps_str}"
+    )
+  endif()
+
+  # Private deps
+  if(_private_immediate)
+    target_link_libraries(${_target_name} PRIVATE ${_private_immediate})
+  endif()
+
+  if(_private_moxygen)
+    list(JOIN _private_moxygen "," _deps_str)
+    set_property(GLOBAL APPEND PROPERTY MOXYGEN_DEFERRED_DEPS
+      "${_target_name}|PRIVATE|${_deps_str}"
+    )
+  endif()
+
+  # Track target
+  set_property(GLOBAL APPEND PROPERTY MOXYGEN_COMPONENT_TARGETS ${_target_name})
+
+  # Install
+  install(
+    TARGETS ${_target_name}
+    EXPORT moxygen-exports
+    ARCHIVE DESTINATION ${LIB_INSTALL_DIR}
+    LIBRARY DESTINATION ${LIB_INSTALL_DIR}
+  )
+
+  # Create alias
+  add_library(moxygen::${_target_name} ALIAS ${_target_name})
+endfunction()
+
+# Resolve deferred dependencies after all targets are defined
+# Call this after all add_subdirectory() calls
+function(moxygen_resolve_deferred_dependencies)
+  # Allow linking targets defined in other directories
+  cmake_policy(SET CMP0079 NEW)
+
+  get_property(_deferred_deps GLOBAL PROPERTY MOXYGEN_DEFERRED_DEPS)
+
+  foreach(_spec IN LISTS _deferred_deps)
+    # Parse the spec: "target|visibility|dep1,dep2,..."
+    string(REPLACE "|" ";" _parts "${_spec}")
+    list(LENGTH _parts _len)
+    if(_len LESS 3)
+      continue()
+    endif()
+
+    list(GET _parts 0 _target)
+    list(GET _parts 1 _visibility)
+    list(GET _parts 2 _deps_str)
+
+    # Split deps by comma
+    string(REPLACE "," ";" _deps "${_deps_str}")
+
+    # Filter to only existing targets (skip deps that weren't generated)
+    set(_valid_deps "")
+    foreach(_dep IN LISTS _deps)
+      if(TARGET ${_dep})
+        list(APPEND _valid_deps ${_dep})
+      endif()
+    endforeach()
+
+    if(_valid_deps)
+      target_link_libraries(${_target} ${_visibility} ${_valid_deps})
+    endif()
+  endforeach()
+endfunction()
+
+# Install headers preserving directory structure
+function(moxygen_install_headers rootName rootDir)
+  file(
+    GLOB_RECURSE MOXYGEN_HEADERS_TOINSTALL
+    RELATIVE ${rootDir}
+    ${rootDir}/*.h
+  )
+  list(FILTER MOXYGEN_HEADERS_TOINSTALL EXCLUDE REGEX test/)
+  list(FILTER MOXYGEN_HEADERS_TOINSTALL EXCLUDE REGEX facebook/)
+  foreach(header ${MOXYGEN_HEADERS_TOINSTALL})
+    get_filename_component(header_dir ${header} DIRECTORY)
+    install(FILES ${rootDir}/${header}
+            DESTINATION include/${rootName}/${header_dir})
+  endforeach()
+endfunction()