Managing Component Backward Compatibility

A component that must build under both v1 and v2 can use the IDF_BUILD_V2 variable to run different CMake code under each build system. IDF_BUILD_V2 is set when the component is evaluated under v2. You can use it to adjust small parts of an existing v1 component, or to include a completely separate CMakeLists.txt for v2. For the specific differences between v1 and v2 that may require this, see Breaking Changes.

Below is a component, my_component, whose CMakeLists.txt is adjusted to include and evaluate a separate v2 file, CMakeLists_v2.txt, when it is evaluated under v2.

Note

Most v1 components should work without modification under v2. This is only a simple, illustrative example of how IDF_BUILD_V2 can be used to evaluate different CMakeLists.txt files for v1 and v2.

Adjusted CMakeLists.txt:

if(IDF_BUILD_V2)
    # Include component CMake code for v2 and return.
    include(CMakeLists_v2.txt)
    return()
endif()

# Here follows the original component CMake code for v1.
idf_component_register(SRCS "my_component.c"
                       PRIV_REQUIRES spi_flash
                       INCLUDE_DIRS "")

The CMakeLists_v2.txt for v2:

idf_component_include(spi_flash)

add_library(${COMPONENT_TARGET} STATIC
    "my_component.c"
)

target_include_directories(${COMPONENT_TARGET} PUBLIC
    "${CMAKE_CURRENT_LIST_DIR}"
)

target_link_libraries(${COMPONENT_TARGET} PRIVATE
    idf::spi_flash
)

For more on writing a native v2 component, see Native CMake Component.

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