CMake build improvements

- Check for Linux (Android TBD once that lands) and C++17
- Move `SAPI_HARDENED_SOURCE` check after compile options are evaluated
- Use a more modern way to set the required C++ standard, compatible with
  Abseil's `ABSL_PROPAGATE_CXX_STD`.
- Scope `-fno-exceptions` and `POSITION_INDEPENDENT_CODE` to SAPI targets
- Increase maximum stack frame size yet again

PiperOrigin-RevId: 422369190
Change-Id: If75405ee43740de90196f52cddc8938482eae851

CMakeLists.txt

@@ -26,24 +26,29 @@ endif()
 
 project(SandboxedAPI C CXX ASM)
 
+# TODO(cblichmann): Enable for Android once support lands
+if(NOT CMAKE_SYSTEM_NAME MATCHES "Linux")
+  message(FATAL_ERROR "Sandboxed API is only supported on Linux")
+endif()
+
 # SAPI-wide setting for the language level
 set(SAPI_CXX_STANDARD 17)
 
+if(NOT CMAKE_CXX_STANDARD)
+  set(CMAKE_CXX_STANDARD ${SAPI_CXX_STANDARD})
+elseif(CMAKE_CXX_STANDARD LESS ${SAPI_CXX_STANDARD})
+  message(FATAL_ERROR
+    "Sandboxed API requires C++17. To ensure ABI compatibility"
+    " build and link all targets of the project with the same"
+    " version of C++."
+  )
+endif()
+
 set(SAPI_BINARY_DIR "${PROJECT_BINARY_DIR}" CACHE INTERNAL "" FORCE)
 set(SAPI_SOURCE_DIR "${PROJECT_SOURCE_DIR}" CACHE INTERNAL "" FORCE)
 
-set(CMAKE_POSITION_INDEPENDENT_CODE TRUE CACHE BOOL "" FORCE)
-
 include(CheckCXXCompilerFlag)
 
-# TODO(cblichmann): Only apply this to SAPI and its dependencies
-add_compile_options(-fno-exceptions)
-
-if(SAPI_HARDENED_SOURCE)
-  add_compile_options(-fstack-protector -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2)
-  add_link_options(-Wl,-z,relro -Wl,-z,now)
-endif()
-
 # Sapi CMake modules, order matters
 list(APPEND CMAKE_MODULE_PATH "${SAPI_SOURCE_DIR}/cmake"
                               "${SAPI_SOURCE_DIR}/cmake/modules")
@@ -56,6 +61,11 @@ include(GNUInstallDirs)
 # Allow the header generator to auto-configure include paths
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 
+if(SAPI_HARDENED_SOURCE)
+  add_compile_options(-fstack-protector -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2)
+  add_link_options(-Wl,-z,relro -Wl,-z,now)
+endif()
+
 if(SAPI_FORCE_COLOR_OUTPUT)
   if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")  # GCC
     add_compile_options(-fdiagnostics-color=always)
@@ -76,33 +86,33 @@ add_library(sapi_base STATIC
   "${SAPI_BINARY_DIR}/sapi_base_force_cxx_linkage.cc"
 )
 add_library(sapi::base ALIAS sapi_base)
-set_target_properties(sapi_base PROPERTIES
+target_compile_features(sapi_base PUBLIC
-  CXX_STANDARD              ${SAPI_CXX_STANDARD}
+  cxx_std_${SAPI_CXX_STANDARD}
-  CXX_STANDARD_REQUIRED     TRUE
-  CXX_EXTENSIONS            FALSE
-  SKIP_BUILD_RPATH          TRUE
-  POSITION_INDEPENDENT_CODE TRUE
 )
-target_include_directories(sapi_base INTERFACE
+set_target_properties(sapi_base PROPERTIES
+  SKIP_BUILD_RPATH          ON
+  POSITION_INDEPENDENT_CODE ON
+)
+target_include_directories(sapi_base PUBLIC
   "${SAPI_BINARY_DIR}"
   "${SAPI_SOURCE_DIR}"
   "${Protobuf_INCLUDE_DIR}"
 )
-if(UNIX)
+target_compile_options(sapi_base PUBLIC -fno-exceptions)
-  set(_sapi_check_no_deprecated
+set(_sapi_check_no_deprecated
   -Wno-deprecated SAPI_HAS_W_NO_DEPRECATED
-  )
+)
-  # For sandbox2/util.cc's CloneAndJump()
+# For sandbox2/util.cc's CloneAndJump()
-  set(_sapi_check_frame_larger_than
+set(_sapi_check_frame_larger_than
-    -Wframe-larger-than=20480 SAPI_HAS_W_FRAME_LARGER_THAN
+  -Wframe-larger-than=40960 SAPI_HAS_W_FRAME_LARGER_THAN
-  )
+)
-  set(_sapi_check_no_deprecated_declarations
+set(_sapi_check_no_deprecated_declarations
   -Wno-deprecated-declarations SAPI_HAS_W_NO_DEPRECATED_DECLARATIONS
-  )
+)
-  set(_sapi_check_no_psabi
+set(_sapi_check_no_psabi
   -Wno-psabi SAPI_HAS_W_NO_PSABI
-  )
+)
-  foreach(check IN ITEMS _sapi_check_no_deprecated
+foreach(check IN ITEMS _sapi_check_no_deprecated
                        _sapi_check_frame_larger_than
                        _sapi_check_no_deprecated_declarations
                        _sapi_check_no_psabi)
@@ -110,10 +120,9 @@ if(UNIX)
   list(GET ${check} 1 var_name)
   check_cxx_compiler_flag(${opt_value} ${var_name})
   if(${var_name})
-      target_compile_options(sapi_base INTERFACE ${opt_value})
+    target_compile_options(sapi_base PUBLIC ${opt_value})
   endif()
-  endforeach()
+endforeach()
-endif()
 
 add_library(sapi_test_main INTERFACE)
 add_library(sapi::test_main ALIAS sapi_test_main)

cmake/abseil-cpp.cmake

@@ -51,15 +51,14 @@ if(error)
   message(FATAL_ERROR "Build step for ${PROJECT_NAME} failed: ${error}")
 endif()
 
-set(_sapi_saved_CMAKE_CXX_STANDARD ${CMAKE_CXX_STANDARD})
 set(_sapi_saved_BUILD_TESTING ${BUILD_TESTING})
 
-set(CMAKE_CXX_STANDARD ${SAPI_CXX_STANDARD})
-set(ABSL_USE_GOOGLETEST_HEAD OFF CACHE BOOL "" FORCE)
-set(ABSL_RUN_TESTS OFF CACHE BOOL "" FORCE)
-set(BUILD_TESTING OFF)  # Avoid errors when re-configuring SAPI
 set(ABSL_CXX_STANDARD ${SAPI_CXX_STANDARD} CACHE STRING "" FORCE)
 set(ABSL_ENABLE_INSTALL ON CACHE BOOL "" FORCE)
+set(ABSL_PROPAGATE_CXX_STD ON CACHE BOOL "" FORCE)
+set(ABSL_RUN_TESTS OFF CACHE BOOL "" FORCE)
+set(ABSL_USE_GOOGLETEST_HEAD OFF CACHE BOOL "" FORCE)
+set(BUILD_TESTING OFF)  # Avoid errors when re-configuring SAPI
 
 add_subdirectory("${SAPI_ABSL_SOURCE_DIR}"
                  "${SAPI_ABSL_BINARY_DIR}" EXCLUDE_FROM_ALL)
@@ -67,6 +66,3 @@ add_subdirectory("${SAPI_ABSL_SOURCE_DIR}"
 if(_sapi_saved_BUILD_TESTING)
   set(BUILD_TESTING "${_sapi_saved_BUILD_TESTING}")
 endif()
-if(_sapi_saved_CMAKE_CXX_STANDARD)
-  set(CMAKE_CXX_STANDARD "${_sapi_saved_CMAKE_CXX_STANDARD}")
-endif()