使用CMake 2.8无法完成交叉编译，附构建结构及调用脚本

Let’s walk through the most likely issues with your setup—older CMake versions like 2.8 have plenty of quirks, and cross-compilation often falls apart due to small path or configuration mistakes. Here’s what to check step by step:

1. Fix the Toolchain File Path #

Your current -DCMAKE_TOOLCHAIN_FILE=../toolchain.cmake is pointing to the wrong location. Let’s map your directory structure:

• When you cd libyang-0.14.78, you’re in /blah/3rdparty/yang/libyang-0.14.78
• ../ would take you to /blah/3rdparty/yang, but your toolchain.cmake lives in /blah/3rdparty

You need to use two levels of parent directories to reach it:

-DCMAKE_TOOLCHAIN_FILE=../../toolchain.cmake

2. Verify Your Toolchain File is Correct #

CMake 2.8 relies heavily on a properly configured toolchain file for cross-compilation. Make sure yours includes these critical variables (adjust paths to match your cross-compiler):

# Set target system (e.g., Linux for embedded targets)
SET(CMAKE_SYSTEM_NAME Linux)

# Path to your cross-compiler binaries
SET(CMAKE_C_COMPILER /path/to/your/cross-gcc)
SET(CMAKE_CXX_COMPILER /path/to/your/cross-g++)

# Optional but recommended: Sysroot for target libraries/headers
SET(CMAKE_SYSROOT /path/to/your/target-sysroot)

# Tell CMake to only search the target sysroot for libraries/headers
SET(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
SET(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
SET(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)

If any of these are missing, CMake will default to your host system’s compiler, which is why cross-compilation fails.

3. Ensure You’re Using a Cross-Compiled PCRE Library #

The PCRE paths you specified (/blah/lib/libpcre.so and /blah/include) look like host system files. Cross-compiling requires linking against libraries built for your target architecture, not your development machine’s.

Replace these paths with the location of your cross-compiled PCRE library and headers, e.g.:

-DPCRE_LIBRARY=/blah/cross-target/lib/libpcre.so
-DPCRE_INCLUDE_DIR=/blah/cross-target/include

4. Fix the Makefile’s Command Chaining #

Using ; after cd means the subsequent cmake command runs in your original working directory (not libyang-0.14.78) if the cd fails silently. Switch to && to ensure the chain only proceeds if the cd succeeds:

prep:
	cd libyang-0.14.78 && \
    cmake -DCMAKE_TOOLCHAIN_FILE=../../toolchain.cmake \
          -DENABLE_BUILD_TESTS=OFF \
          -DENABLE_VALGRIND_TESTS=OFF \
          -DPCRE_LIBRARY=/blah/cross-target/lib/libpcre.so \
          -DPCRE_INCLUDE_DIR=/blah/cross-target/include \
          -DCMAKE_BUILD_TYPE=Release

5. Clear CMake Cache Residues #

Older CMake versions (like 2.8) don’t always overwrite cached values properly. If you’ve run cmake before, delete the cached files in libyang-0.14.78 to start fresh:

rm -rf libyang-0.14.78/CMakeCache.txt libyang-0.14.78/CMakeFiles

6. Check libyang 0.14.78’s CMake Compatibility #

Double-check that libyang 0.14.78’s CMakeLists.txt supports CMake 2.8. Some modern CMake commands (like target_link_libraries with keyword arguments) weren’t available in 2.8. If you see errors about unknown commands, you may need to either:

• Patch the libyang CMakeLists.txt to use 2.8-compatible syntax
• Upgrade to a newer CMake version (if your environment allows it)

Start with the path and toolchain fixes first—those are the most common culprits for this kind of failure.

内容的提问来源于stack exchange，提问作者codenamezero