Change INTERFACE to SYSTEM INTERFACE target_include_directories

Should not be merged upstream, just a proof of concept

src/CMakeLists.txt

@@ -63,7 +63,7 @@ macro(pico_simple_hardware_headers_target NAME)
     if (NOT TARGET hardware_${NAME}_headers)
         add_library(hardware_${NAME}_headers INTERFACE)
 
-        target_include_directories(hardware_${NAME}_headers INTERFACE ${CMAKE_CURRENT_LIST_DIR}/include)
+        target_include_directories(hardware_${NAME}_headers SYSTEM INTERFACE ${CMAKE_CURRENT_LIST_DIR}/include)
         target_link_libraries(hardware_${NAME}_headers INTERFACE pico_base_headers)
         if (NOT PICO_NO_HARDWARE)
             target_link_libraries(hardware_${NAME}_headers INTERFACE hardware_structs hardware_claim)
@@ -82,7 +82,7 @@ macro(pico_simple_hardware_headers_only_target NAME)
         # pico_add_sdk_impl_library(hardware_${NAME})
         add_library(hardware_${NAME} INTERFACE)
 
-        target_include_directories(hardware_${NAME} INTERFACE ${CMAKE_CURRENT_LIST_DIR}/include)
+        target_include_directories(hardware_${NAME} SYSTEM INTERFACE ${CMAKE_CURRENT_LIST_DIR}/include)
         target_link_libraries(hardware_${NAME} INTERFACE pico_base_headers)
         if (NOT PICO_NO_HARDWARE)
             target_link_libraries(hardware_${NAME} INTERFACE hardware_structs)
@@ -118,4 +118,4 @@ endfunction()
 
 include(${PICO_PLATFORM_CMAKE_FILE})
 
-pico_promote_common_scope_vars()
+pico_promote_common_scope_vars()

src/common/pico_base/CMakeLists.txt

@@ -1,6 +1,6 @@
 if (NOT TARGET pico_base_headers)
     add_library(pico_base_headers INTERFACE)
-    target_include_directories(pico_base_headers INTERFACE include ${CMAKE_BINARY_DIR}/generated/pico_base)
+    target_include_directories(pico_base_headers SYSTEM INTERFACE include ${CMAKE_BINARY_DIR}/generated/pico_base)
 
     # PICO_BUILD_DEFINE: PICO_BOARD, Name of board, type=string, default=CMake PICO_BOARD variable, group=pico_base
     target_compile_definitions(pico_base_headers INTERFACE
@@ -10,4 +10,4 @@ if (NOT TARGET pico_base_headers)
 
     list(APPEND PICO_SDK_POST_LIST_FILES ${CMAKE_CURRENT_LIST_DIR}/generate_config_header.cmake)
     pico_promote_common_scope_vars()
-endif()
+endif()

src/common/pico_base/generate_config_header.cmake

@@ -25,5 +25,5 @@ file(GENERATE
 configure_file( ${CMAKE_CURRENT_LIST_DIR}/include/pico/version.h.in ${CMAKE_BINARY_DIR}/generated/pico_base/pico/version.h)
 
 foreach(DIR IN LISTS PICO_INCLUDE_DIRS)
-    target_include_directories(pico_base_headers INTERFACE ${DIR})
-endforeach()
+    target_include_directories(pico_base_headers SYSTEM INTERFACE ${DIR})
+endforeach()

src/common/pico_stdlib/CMakeLists.txt

@@ -1,11 +1,11 @@
 if (NOT TARGET pico_stdlib_headers)
     add_library(pico_stdlib_headers INTERFACE)
-    target_include_directories(pico_stdlib_headers INTERFACE include)
+    target_include_directories(pico_stdlib_headers SYSTEM INTERFACE include)
     target_link_libraries(pico_stdlib_headers INTERFACE
             hardware_gpio
             hardware_uart
             hardware_divider
             pico_time
             pico_util
     )
-endif()
+endif()

src/host/pico_platform/CMakeLists.txt

@@ -9,7 +9,7 @@ if (NOT TARGET pico_platform_headers)
             PICO_BUILD=1
     )
 
-    target_include_directories(pico_platform_headers INTERFACE ${CMAKE_CURRENT_LIST_DIR}/include)
+    target_include_directories(pico_platform_headers SYSTEM INTERFACE ${CMAKE_CURRENT_LIST_DIR}/include)
 endif()
 
 if (NOT TARGET pico_platform)

src/rp2_common/cyw43_driver/CMakeLists.txt

@@ -28,7 +28,7 @@ if (EXISTS ${PICO_CYW43_DRIVER_PATH}/${CYW43_DRIVER_TEST_FILE})
             ${PICO_CYW43_DRIVER_PATH}/src/cyw43_lwip.c
             ${PICO_CYW43_DRIVER_PATH}/src/cyw43_ctrl.c
             )
-    target_include_directories(cyw43_driver_base INTERFACE
+    target_include_directories(cyw43_driver_base SYSTEM INTERFACE
             ${PICO_CYW43_DRIVER_PATH}/src
             ${PICO_CYW43_DRIVER_PATH}/firmware
             )

src/rp2_common/hardware_base/CMakeLists.txt

@@ -1,3 +1,3 @@
 add_library(hardware_base INTERFACE)
-target_include_directories(hardware_base INTERFACE ${CMAKE_CURRENT_LIST_DIR}/include)
-target_link_libraries(hardware_base INTERFACE pico_base_headers)
+target_include_directories(hardware_base SYSTEM INTERFACE ${CMAKE_CURRENT_LIST_DIR}/include)
+target_link_libraries(hardware_base INTERFACE pico_base_headers)

src/rp2_common/pico_platform/CMakeLists.txt

@@ -7,7 +7,7 @@ if (NOT TARGET pico_platform_headers)
             PICO_BUILD=1
     )
 
-    target_include_directories(pico_platform_headers INTERFACE ${CMAKE_CURRENT_LIST_DIR}/include)
+    target_include_directories(pico_platform_headers SYSTEM INTERFACE ${CMAKE_CURRENT_LIST_DIR}/include)
 
     target_link_libraries(pico_platform_headers INTERFACE hardware_regs)
 endif()
@@ -22,4 +22,4 @@ endif()
 
 function(pico_add_platform_library TARGET)
     target_link_libraries(pico_platform INTERFACE ${TARGET})
-endfunction()
+endfunction()

tools/CMakeLists.txt

@@ -37,9 +37,9 @@ function(pico_generate_pio_header TARGET PIO)
     add_dependencies(${TARGET} ${HEADER_GEN_TARGET})
     get_target_property(target_type ${TARGET} TYPE)
     if ("INTERFACE_LIBRARY" STREQUAL "${target_type}")
-        target_include_directories(${TARGET} INTERFACE ${HEADER_DIR})
+        target_include_directories(${TARGET} SYSTEM INTERFACE ${HEADER_DIR})
     else()
-        target_include_directories(${TARGET} PUBLIC ${HEADER_DIR})
+        target_include_directories(${TARGET} SYSTEM PUBLIC ${HEADER_DIR})
     endif()
 endfunction()