我正在用 conan2 试试运气,但我很难用它来构建我的库。准确地说,我的库打包得很好,但是 test_package 调用失败,因为它找不到所述库。这是 conan 生成的 CMake 错误
cmakedeps_macros.cmake
:
======== Testing the package: Building ========
cojson/0.1.0 (test package): Calling build()
cojson/0.1.0 (test package): Running CMake.configure()
cojson/0.1.0 (test package): RUN: cmake -G "Visual Studio 17 2022" -DCMAKE_TOOLCHAIN_FILE="C:/dev/cojson/test_package/build/msvc-193-x86_64-20-release/generators/conan_toolchain.cmake" -DCMAKE_INSTALL_PREFIX="C:/dev/cojson/test_package" -DCMAKE_POLICY_DEFAULT_CMP0091="NEW" "C:\dev\cojson\test_package"
...(cmake stuff)...
CMake Error at build/msvc-193-x86_64-20-release/generators/cmakedeps_macros.cmake:67 (message):
Library 'cojson::cojson' not found in package. If 'cojson::cojson' is a
system library, declare it with 'cpp_info.system_libs' property
我不太擅长看到幕后的情况。我对 cmake 有相当好的理解,但我不太明白如何将目标导入到 test_package 上下文中。所以我对这个错误有点迷失。这是我的项目结构:
├── CMakeLists.txt
├── src
│ ├── CMakeLists.txt
│ └── main.cpp
├── include
│ └── cojson
│ └── myheader.hpp
├── tests
│ ├── CMakeLists.txt
│ └── tests.cpp
├── test_package
│ ├── conanfile.py
│ ├── CMakeLists.txt
│ └── src
│ └── example.cpp
└── LICENSE
我已经浏览了所有教程示例(当然工作完美)并浏览了文档,但我没有找到关于为什么目标可能不知道的具体提示。我的猜测是
目标使用不同的导出名称:确实目标名为 cojson_core 但我将导出名称更改为 cojson,如下所示:
set_target_properties(cojson_core PROPERTIES EXPORT_NAME cojson)
那么这应该有效吗?
以下是相关部分:
conanfile.py(根):
import os
from conan import ConanFile
from conan.tools.cmake import CMakeToolchain, CMake, cmake_layout
from conan.tools.build import check_min_cppstd
from conan.tools.files import copy
class cojsonConan(ConanFile):
name = "cojson"
version = "0.1.0"
# Optional metadata
license = "https://github.com/MartyMcFlyInTheSky/cojson/blob/master/LICENSE"
author = "Samuel Beer"
url = "https://github.com/MartyMcFlyInTheSky/cojson"
description = "A C++ JSON library using coroutines"
topics = ("json", "coroutines", "cpp20")
# Binary configuration
settings = "os", "compiler", "build_type", "arch"
options = {
"shared": [True, False],
"fPIC": [True, False],
}
default_options = {
"shared": False,
"fPIC": True,
}
# Sources located in same place
exports = ["LICENSE"]
exports_sources = "CMakeLists.txt", "src/*", "include/*", "tests/*"
def validate(self):
check_min_cppstd(self, "20")
def config_options(self):
if self.settings.os == "Windows":
del self.options.fPIC
def configure(self):
# delete fPIC option if shared
if self.options.shared:
# If os=Windows, fPIC will have been removed in config_options()
# use rm_safe to avoid double delete errors
self.options.rm_safe("fPIC")
def requirements(self):
self.test_requires("gtest/1.14.0")
def _configure_cmake(self):
cmake = CMake(self)
cmake.configure()
return cmake
def layout(self):
cmake_layout(self)
def generate(self):
tc = CMakeToolchain(self)
tc.generate()
def build(self):
cmake = self._configure_cmake()
cmake.build()
# if not self.conf.get("tools.build:skip_test", default=False):
cmake.test()
def package(self):
copy(self, "LICENSE", src=self.source_folder, dst=os.path.join(self.package_folder, "licenses"))
cmake = self._configure_cmake()
cmake.install()
# consumer information
def package_info(self):
self.cpp_info.libs = ["cojson"]
conanfile.py(测试包):
import os
from conan import ConanFile
from conan.tools.cmake import CMake, cmake_layout
from conan.tools.build import can_run
class cojsonConan(ConanFile):
settings = "os", "compiler", "build_type", "arch"
generators = "CMakeDeps", "CMakeToolchain"
def requirements(self):
self.requires(self.tested_reference_str)
def build(self):
cmake = CMake(self)
cmake.configure()
cmake.build()
def layout(self):
cmake_layout(self)
def test(self):
if can_run(self):
cmd = os.path.join(self.cpp.build.bindir, "example")
self.run(cmd, env="conanrun")
编辑1:
评论中的@Tsyvarev 有一个值得注意的想法,即不导出单独的目标名称。所以我所做的是将我的主要目标留在 cojson_core 并将其别名为 cojson::cojson_core 以保持一致性,并在测试和 test_package CMakeFiles:中进行调整
test_package/CMakeLists.txt
...
target_link_libraries(example cojson::cojson_core)
...
在 conanfile 中,我还必须调整导出的库:
conanfile.py
def package_info(self):
# self.cpp_info.libs = ["cojson"]
self.cpp_info.libs = ["cojson_core"]
self.cpp_info.set_property("cmake_target_name", "cojson::cojson_core")
这至少让我更进一步,因为似乎找到了 cojson::cojson_core 。但是:我现在收到另一个错误,指出它不知道 lib 头文件在哪里:
C:\dev\cojson\test_package\src\example.cpp(2,10): fatal error C1083: Datei (Include) kann nicht geöffnet werden: "cojson/cojson.hpp": No such file or directory [C:\dev\cojson\test_package\build\msvc-193-x
86_64-20-release\example.vcxproj]
这非常令人困惑,因为 test_package 显然已经找到了应该声明包含目录的 cojson::cojson_core 目标。我单独用 cmake 测试了 test_package,如果我这样做,它就可以工作:在
cojson/test_package/
执行
cmake -S . -B build -G "MinGW Makefiles" -DCMAKE_INSTALL_PREFIX=C:\dev\installcojson
cmake --build build
目标已找到,包含目录也已找到。我不知道为什么柯南这样做时它不起作用。有任何想法吗?也许有人可以解释 conan 如何定义目标:这些“包装”目标是 conan 为每个实际的 cmake 目标定义的吗?
编辑2:
丢失头文件的问题现已解决。我已经排除了该行
set_target_properties(cojson_core PROPERTIES PUBLIC_HEADER
${CMAKE_CURRENT_SOURCE_DIR}/../include/cojson/cojson.hpp;
)
出于某种原因。把它插回去终于让我构建了这个包。尽管如此,问题仍未解决,因为我希望我的目标有一个不同的导出名称:cojson。我尝试再次调整 conanfile.py 中的属性
def package_info(self):
# self.cpp_info.libs = ["cojson"]
self.cpp_info.libs = ["cojson"]
self.cpp_info.set_property("cmake_target_name", "cojson::cojson")
...a上面臭名昭著的错误又回来了。目标没有被识别怎么办?
问题是 conan 工具链不仅会查找配置模块,还会使用
find_library()
test_package/build/msvc../generators/cmakedeps_macros.cmake:23:
find_library(CONAN_FOUND_LIBRARY NAMES ${_LIBRARY_NAME} PATHS ${package_libdir}
NO_DEFAULT_PATH NO_CMAKE_FIND_ROOT_PATH)
因此,二进制文件名称与 conanfile.py 的库名称完全匹配非常重要。解决方案
set_target_properties(cojson_core PROPERTIES OUTPUT_NAME "cojson")
到与conanfile.py中定义的库相对应的目标:
def package_info(self):
self.cpp_info.libs = ["cojson"]