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cmakedoxygenconan

How to run the Doxygen binary installed by its Conan package inside a CMake script?

Currently, I programmatically generate a conanfile.txt using two functions I have written:

message(STATUS "Fetching Doxygen from Conan.")
add_project_dependencies(${PROJECT_NAME}_docs CONAN BUILD_DEPS REQUIRED doxygen/1.9.1)
link_project_dependencies(${PROJECT_NAME}_docs PRIVATE)

Together, they create ${CMAKE_BINARY_DIR}/deps_${PROJECT_NAME}_docs/conanfile.txt:


[requires]


[build_requires]
doxygen/1.9.1

[generators]
cmake_find_package

[options]


[imports]

And then they run conan install . in that directory and Doxygen is built successfully. As I use cmake_find_package generator, a Finddoxygen.cmake is created inside that directory as well. So far, so good. However, finding the package like this:

find_package(doxygen REQUIRED)

Doesn't provide the DOXYGEN_EXECUTABLE like it's supposed to (it is set to DOXYGEN_EXECUTABLE-NOTFOUND). Neither does it provide the doxygen_add_docs() for use. So according to FindDoxygen docs , and as the conan-generated Finddoxygen.cmake contains target definition for doxygen::doxygen I thought I should use the generator expressions (as per here):

add_custom_target(docs
    COMMAND $<TARGET_FILE:doxygen::doxygen> ${DOXYGEN_OUT}
    WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
    COMMENT "Generating API documentation with Doxygen"
    VERBATIM)

But this generates the error: Target "doxygen::doxygen" is not an executable or library. Neither that or LOCATION target property work; I used this snippet to view target's properties:

doxygen::doxygen IMPORTED = TRUE
doxygen::doxygen IMPORTED_GLOBAL = FALSE
doxygen::doxygen INTERFACE_COMPILE_OPTIONS = ;
doxygen::doxygen INTERFACE_LINK_LIBRARIES = ;xapian::xapian;ZLIB::ZLIB;$<$<STREQUAL:$<TARGET_PROPERTY:TYPE>,SHARED_LIBRARY>:>;$<$<STREQUAL:$<TARGET_PROPERTY:TYPE>,MODULE_LIBRARY>:>;$<$<STREQUAL:$<TARGET_PROPERTY:TYPE>,EXECUTABLE>:>
doxygen::doxygen NAME = doxygen::doxygen
doxygen::doxygen TYPE = INTERFACE_LIBRARY

And it doesn't provide any property containing the path to the doxygen binary that is generated at ~/.conan/data/doxygen/1.9.1/_/_/package/ff3ada3b39a52bebe18da7d8c32a4aead970f75c/bin/doxygen.

So how can I use it inside my CMake scripts? Am I missing something? Because looking at the example usage in this resolved issue, it seems that my approach is correct and it should have found the binary and set DOXYGEN_EXECUTABLE.

Solution

  • This can be achieved by using CONAN_BIN_DIRS_DOXYGEN/doxygen.

    Also list of other useful variables: https://docs.conan.io/en/latest/reference/generators/cmake.html