c++ - 使用 Cmake 构建 asmJit 示例

Question

我正在尝试构建一个基于 asmJit 的示例项目。

我有以下设置Asm测试

• main.cpp
• CmakeLists.txt
• 图书馆
  • asmjit(里面是来自 github 仓库的 CmakeList.txt)。
  • CMakeLists.txt(内容:add_subdirectory(asmjit))
• build

我的第一个CmakeLists.txt的内容是:

cmake_minimum_required(VERSION 2.8)
project(asmJitTest)

add_subdirectory(libs)
include_directories(${asmJitTest_SOURCE_DIR} ${asmJitTest_SOURCE_DIR}/libs/asmjit/src)
add_executable(JitTest main.cpp)
target_link_libraries(JitTest asmjit)

我可以成功构建这个项目，获得 Visual Studio 解决方案。但是如果我尝试在 Visual Studio 中运行它，我会遇到各种“ Unresolved external 错误”，例如。

1   error LNK2001: unresolved external symbol "struct asmjit::X86RegData   
    const asmjit::x86RegData" (?x86RegData@asmjit@@3UX86RegData@1@B)    main.obj    JitTest

我不明白为什么会出现链接错误。我是 cmake 的新手，这整个过程都是从零开始的。有人可以指出我正确的方向吗？

Answer 1

您可以将 asmjit 编译为动态链接库，只需将其 CMakeLists.txt 包含在您的 cmake 脚本中即可:

Set(ASMJIT_DIR "/relative/dir/to/your/asmjit")
Include("${ASMJIT_DIR}/CMakeLists.txt")

# AsmJit should have already taken care of include directories, if you
# are not sure you can add it, but shouldn't be necessary.
Include_Directories(${ASMJIT_DIR})

# Then in your target you should be able to use:
Target_Link_Libraries(YourTarget asmjit ${ASMJIT_DEPS})

或者，我发现将 asmjit 作为静态库嵌入更加可靠，将整个 asmjit 嵌入到您的项目中。 AsmJit 对此有内置支持:

# Tell asmjit that it will be embedded.
Set(ASMJIT_EMBED TRUE)
Add_Definitions(-DASMJIT_STATIC)

Set(ASMJIT_DIR "/relative/dir/to/your/asmjit")
Include("${ASMJIT_DIR}/CMakeLists.txt")

# If you add a library / executable, include asmjit sources.
Add_Executable(YourTarget main.cpp ${ASMJIT_SRC})

# You still have to include asmjit dependencies.
Target_Link_Libraries(YourTarget ${ASMJIT_DEPS})

与动态或静态构建 asmjit 相比，第二种方法有一个很大的优势，它可以通过这种方式嵌入到动态链接库中，而在 Linux 和所有需要您使用 -fPIC 的平台下都不会出现问题>，因为默认情况下 cmake 不会将 -fPIC 放入静态库构建中，但这需要更长时间的讨论，并且与您的问题无关。