Antlr4 with C++ and CMake - cmake

I'm trying to use antlr4 with C++. I have the following CMakeLists.txt in my root directory:
cmake_minimum_required(VERSION 3.10)
project(demo VERSION 0.1 DESCRIPTION "demo")
include_directories(${CMAKE_CURRENT_BINARY_DIR})
set(CMAKE_CXX_STANDARD 17)
#############################################################################
# ANTLR SPECIFIC CMAKE COMMANDS
# This is derived from: https://github.com/blorente/antlr-4.7-cpp-cmake-base
#############################################################################
# Set the ocation of the JAR.
set(ANTLR4CPP_JAR_LOCATION ${CMAKE_SOURCE_DIR}/antlr/jar/antlr.jar)
# Add external build for antlrcpp.
include (${CMAKE_SOURCE_DIR}/antlr/runtime/ExternalAntlr4Cpp.cmake)
# add antrl4cpp artifacts to project environment.
include_directories( ${ANTLR4CPP_INCLUDE_DIRS} )
link_directories( ${ANTLR4CPP_LIBS} )
# message(WARNING "Found antlr4cpp libs: ${ANTLR4CPP_LIBS} and includes: ${ANTLR4CPP_INCLUDE_DIRS} ")
# Build the lexer/parser .h/.cpp files off the g4 grammar files.
antlr4cpp_process_grammar(demo demoparser
${CMAKE_SOURCE_DIR}/grammar/DemoLexer.g4
${CMAKE_SOURCE_DIR}/grammar/DemoParser.g4)
# include the generated files from the grammar/lexer.
include_directories(${antlr4cpp_include_dirs_demoparser})
#############################################################################
# Build demo
add_executable(demo main.cpp ${antlr4cpp_src_files_demoparser})
# Add dependencies for antlr
add_dependencies(demo antlr4cpp antlr4cpp_generation_demoparser)
target_link_libraries(demo antlr4-runtime)
I have, more or less, copied the example from: the "official" cmake/antlr tutorial. For brevity I have omitted the contents of include (${CMAKE_SOURCE_DIR}/antlr/runtime/ExternalAntlr4Cpp.cmake)
So the files are all in the same structure, except the jar. I just include it as a project file and, as you can see from the set(ANTLR4CPP_JAR_LOCATION) command, it resides where I want it.
When I build this, I get this error:
dyld: Library not loaded: libantlr4-runtime.4.7.1.dylib
Referenced from: /path/to/demo/cmake-build-debug/demo
Reason: image not found
However, when I look in: /path/to/demo/cmake-build-debug/external/antlr4cpp/lib/ I see the libantlr4-runtime.4.7.1.dylib file that should be referenced by using the target_link_libraries(demo antlr4-runtime) command. There are static libraries in there as well.
Am I missing something? Why is CMake not finding the static or dylib files it's supposed to?

I didn't realize, right before I started this, that I ran brew install antlr4-cpp-runtime. Which installed the headers to the path. I did this on my machine, but not on any of the other machines that build this project. The outstanding problem is why is it not deterministic is if the runtime isn't installed. But it works immediately upon installing the runtime.

Related

install targets after pybind11_add_module in cmake and Yocto

I am trying to use python to interfacing my own c++ library. Actually I can do it manually copying pybind11_example.so to the target device. I hope to do this by using install(TARGETS...
I found this link. But it doesn't help in my Yocto build.
This is my CMakeLists.txt:
cmake_minimum_required(VERSION 3.14.4)
project(pybind11_example)
set(CMAKE_INCLUDE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/../lib/math/include")
find_package(PythonLibs REQUIRED)
set(PYTHON_MODULE_EXTENSION ".so" CACHE INTERNAL "Cross python lib extension")
find_package(pybind11 REQUIRED)
pybind11_add_module(${PROJECT_NAME} pybind11_wrapper.cpp)
target_include_directories(${PROJECT_NAME} PRIVATE ${CMAKE_INCLUDE_PATH})
target_link_libraries(${PROJECT_NAME} PRIVATE simplemath)
include(GNUInstallDirs)
# without lines below, yocto build works fine
install(TARGETS ${PROJECT_NAME}
COMPONENT python
RUNTIME DESTINATION "${CMAKE_INSTALL_BINDIR}"
LIBRARY DESTINATION "${CMAKE_INSTALL_LIBDIR}"
ARCHIVE DESTINATION "${CMAKE_INSTALL_LIBDIR}")
This is the error from devtool build:
ERROR: pybind11-example-1.0+git999-r0 do_package: QA Issue: pybind11-example: Files/directories were installed but not shipped in any package:
/usr/lib/pybind11_example.so
Please set FILES such that these items are packaged. Alternatively if they are unneeded, avoid installing them or delete them within do_install.
pybind11-example: 1 installed and not shipped files. [installed-vs-shipped]
ERROR: pybind11-example-1.0+git999-r0 do_package: Fatal QA errors found, failing task.
Oops, I found the reason. The problem was not in cmake but in .bb file.
After I add FILES_${PN} += "/usr/lib" in the .bb, it works fine.
For more detail, please see this link.

Minimal protobuf c++ installation for CMake use

I'm trying to use the CMake functions protobuf_generate in one of my projects. However, I'd like to the build as lightweight as possible. If at all possible I'd like to do this without having to compile protobuf's source code, or install some package on my (windows) machine.
Is there a way to just download binaries and headers and tell CMake: "Here is everything you need", so I can swap new proto versions whenever I feel like?
# CMakeList.txt : Top-level CMake project file, do global configuration
# and include sub-projects here.
#
cmake_minimum_required (VERSION 3.5)
project ("CMakeProject1")
set(TARGET_NAME CMakeProject1)
SET(PROTOBUF_INCLUDE_DIR "/path/to/include")
SET(PROTOBUF_LIBRARY "/path/to/libprotobuf.lib")
SET(PROTOBUF_PROTOC_EXECUTABLE "/path/to/protoc.exe")
find_package(Protobuf)
protobuf_generate_cpp(PROTO_SRCS PROTO_HDRS path/to/some_object.proto)
add_library(${TARGET_NAME} STATIC ${PROTO_SRCS} ${PROTO_HDRS})

Why my <package>-config.cmake have <package>_include_dir and <package>_librairies empty

I am trying to make a cross-platform CMake for my project (Windows and Linux).
I need to use external libraries (yaml-cpp). On Linux, I just had to do an apt get and use find_package. But on Windows, I need to append the CMAKE_MODULE_PATH in order for my program to find the yaml-cpp-config.cmake.
So I start by installing yaml-cpp (https://github.com/jbeder/yaml-cpp) with CMake GUI 3.16 and mingw32 (mingw32-make install).
I have tried the library on a hello world project, and it works fine.
cmake_minimum_required(VERSION 3.1)
project (yaml_test)
set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_CXX_EXTENSIONS OFF)
message (STATUS "Yaml-cpp include = $ENV{YAML_CPP_INCLUDE_DIR}")
message (STATUS "Yaml-cpp library = $ENV{YAML_CPP_LIBRARIES}")
include_directories ($ENV{YAML_CPP_INCLUDE_DIR})
add_executable(yaml_test main.cpp)
target_link_libraries(yaml_test $ENV{YAML_CPP_LIBRARIES})
But now, I want to include the library in my project and use find_package. But the yaml-cpp-config.cmake looks like this:
# - Config file for the yaml-cpp package
# It defines the following variables
# YAML_CPP_INCLUDE_DIR - include directory
# YAML_CPP_LIBRARIES - libraries to link against
# Compute paths
get_filename_component(YAML_CPP_CMAKE_DIR "${CMAKE_CURRENT_LIST_FILE}" PATH)
set(YAML_CPP_INCLUDE_DIR "")
# Our library dependencies (contains definitions for IMPORTED targets)
include("${YAML_CPP_CMAKE_DIR}/yaml-cpp-targets.cmake")
# These are IMPORTED targets created by yaml-cpp-targets.cmake
set(YAML_CPP_LIBRARIES "")
The YAML_CPP_INCLUDE_DIR and YAML_CPP_LIBRARIES variables are empty, and even if CMake found yaml-cpp-config.cmake, It doesn't work. So what do I have missing in the installation of yaml-cpp? Should I have set the paths by hand?
The absence of definition of YAML_CPP_INCLUDE_DIR and YAML_CPP_LIBRARIES variables is the issue with the yaml-cpp project which is already reported here.
Instead of variables described in this config file, use target yaml-cpp:
add_executable(yaml_test main.cpp)
# This provides both include directories and libraries.
target_link_libraries(yaml_test yaml-cpp)
Linking with an IMPORTED target (yaml-cpp in this case) is known as CMake "modern way".

Cmake and vcpkg - find the correct library name

I have troubles finding out the right "library target name" to be used in a cmake file, for packages installed using vcpkg.
In example, I installed the gtest package using vcpkg install gtest. My sample cmake file looks like:
#CMakeLists.txt
cmake_minimum_required(VERSION 3.0)
project(example)
add_executable(main main.cpp)
find_package(gtest REQUIRED)
target_link_libraries(main gtest) # here, "gtest" is not the right name!
Running cmake, a solution for Visual Studio is generated, but after running cmake --build ., I get the error:
../use-cmake-vcpkg\main.cpp(1): fatal error C1083: Cannot open include file: 'gtest/gtest.h': No such file or directory ..
Turns out the line: target_link_libraries(main gtest) isn't correct, and I need to use another "name" to include/link the gtest package.
Is there a way (using cmake or vcpkg) to find out what is the correct target name to be used? (for gtest in this case, but also for any other pacakage?)
When use find_package(XXX), it can work in two modes: MODULE and CONFIG. And resulted variables and targets of this call depend on the mode.
If FindXXX.cmake file exists (and can be found), the MODULE mode is used and given file is processed. Otherwise, if the package is shipped with XXXConfig.cmake file, CONFIG mode is used and given file is processed. If none of this file exists, CMake emits an error (if called with REQUIRED keyword) or a warning (without REQUIRED keyword).
In case of gtest package, CMake is shipped with FindXXX.cmake script, so this script is processed in MODULE mode. You may find description of this script in the documentation, which tells that you need to use GTest::GTest target for link with gtest:
target_link_libraries(main GTest::GTest)
Not all packages provide a CMake library definition. If you're lucky, then vcpkg install will show you the name:
$ ./vcpkg install openssl
The package openssl is compatible with built-in CMake targets:
find_package(OpenSSL REQUIRED)
target_link_libraries(main PRIVATE OpenSSL::SSL OpenSSL::Crypto)
This will work even if you've already installed the package, so you can use it anytime to query the package name.
On the other hand, if vcpkg install <pkg> doesn't say anything about CMake, then you need to include it manually in your CMake file, by finding the include path and the library files.
Here is an example of such a case, here for the live555 library:
# Use one of the headers to locate the include location
find_path(LIVE555_INCLUDE_DIR liveMedia.hh)
# Find the libraries
find_library(LIVE555_LIBRARY1 liveMedia)
find_library(LIVE555_LIBRARY2 groupsock)
find_library(LIVE555_LIBRARY3 BasicUsageEnvironment)
find_library(LIVE555_LIBRARY4 UsageEnvironment)
add_executable(rtsp testRTSPClient.cpp)
target_include_directories(rtsp PRIVATE ${LIVE555_INCLUDE_DIR})
target_link_libraries(rtsp PRIVATE ${LIVE555_LIBRARY1} ${LIVE555_LIBRARY2} ${LIVE555_LIBRARY3} ${LIVE555_LIBRARY4})

Making a CMake library accessible by other CMake packages automatically

I have one project that produces a library:
project (myCoolLibrary)
ADD_LIBRARY(my_cool_library SHARED ${mysources_SRC})
And another project that should be using this library:
find_package (myCoolLibrary REQUIRED)
INCLUDE_DIRECTORIES("${myCoolLibrary_INCLUDE_DIRS}" )
add_executable(myCoolExe ${my_sources_SRC} )
TARGET_LINK_LIBRARIES(myCoolExe ${myCoolLibrary_LIBRARIES} )
Is there a way that I can change the first file so that the second file works automatically? That by running CMake on the first file and then running make on the output, then running CMake on the second file, CMake is able to find the package?
An answer where I just give the address of where the first project is built to the second package is also acceptable.
Taking the code found in a blog post by #daniperez - Use CMake-enabled libraries in your CMake project (III) - I've come up with the following minimal solution:
myCoolLibrary/CMakeLists.txt
cmake_minimum_required(VERSION 3.3)
project(myCoolLibrary)
function(my_export_target _target _include_dir)
file(
WRITE "${CMAKE_CURRENT_BINARY_DIR}/${_target}Config.cmake"
"
include(\"\$\{CMAKE_CURRENT_LIST_DIR\}/${_target}Targets.cmake\")
set_property(
TARGET ${_target}
APPEND PROPERTY
INTERFACE_INCLUDE_DIRECTORIES \"${_include_dir}\"
)
"
)
export(TARGETS ${_target} FILE "${CMAKE_CURRENT_BINARY_DIR}/${_target}Targets.cmake")
# NOTE: The following call can pollute your PC's CMake package registry
# See comments/alternatives below
export(PACKAGE ${_target})
endfunction(my_export_target)
...
add_library(${PROJECT_NAME} SHARED ${mysources_SRC})
my_export_target(${PROJECT_NAME} "${CMAKE_CURRENT_SOURCE_DIR}")
myCoolExe/CMakeLists.txt
cmake_minimum_required(VERSION 3.3)
project(myCoolExe)
find_package(myCoolLibrary REQUIRED)
...
add_executable(${PROJECT_NAME} ${my_sources_SRC})
target_link_libraries(${PROJECT_NAME} myCoolLibrary)
To make it reusable I have packed everything into my_export_target(). And I'm friend of self-propagating properties like INTERFACE_INCLUDE_DIRECTORIES.
As commented by #ruslo, using export(PACKAGE ...) can pollute your package registry. So alternatively you can:
Write the target configuration files directly to some dedicated place specific for a certain toolchain
See e.g. How to install your custom CMake-Find module and 0003659: FIND_PACKAGE command improvements.
Set CMAKE_MODULE_PATH via the second project's CMake command line (injecting the search path(s) from the outside). If you are building the two projects anyway with a build script, then this is the most direct way to propagate the module search path(s).
Additional References
export()
CMake/Tutorials/Package Registry
Unable to find Eigen3 with CMake
How to instruct CMake to use the build architecture compiler