使用CMake构建错误

Question

我在尝试使用 CMake 构建 flex 和 lemon 项目时遇到构建错误。你能帮我找出问题所在吗？

$ make
/usr/bin/cmake -H/home/dac/ClionProjects/openshell -B/home/dac/ClionProjects/openshell --check-build-system CMakeFiles/Makefile.cmake 0
/usr/bin/cmake -E cmake_progress_start /home/dac/ClionProjects/openshell/CMakeFiles /home/dac/ClionProjects/openshell/CMakeFiles/progress.marks
make -f CMakeFiles/Makefile2 all
make[1]: Entering directory '/home/dac/ClionProjects/openshell'
make -f CMakeFiles/lemon.dir/build.make CMakeFiles/lemon.dir/depend
make[2]: Entering directory '/home/dac/ClionProjects/openshell'
cd /home/dac/ClionProjects/openshell && /usr/bin/cmake -E cmake_depends "Unix Makefiles" /home/dac/ClionProjects/openshell /home/dac/ClionProjects/openshell /home/dac/ClionProjects/openshell /home/dac/ClionProjects/openshell /home/dac/ClionProjects/openshell/CMakeFiles/lemon.dir/DependInfo.cmake --color=
make[2]: Leaving directory '/home/dac/ClionProjects/openshell'
make -f CMakeFiles/lemon.dir/build.make CMakeFiles/lemon.dir/build
make[2]: Entering directory '/home/dac/ClionProjects/openshell'
make[2]: Nothing to be done for 'CMakeFiles/lemon.dir/build'.
make[2]: Leaving directory '/home/dac/ClionProjects/openshell'
/usr/bin/cmake -E cmake_progress_report /home/dac/ClionProjects/openshell/CMakeFiles  1
[ 16%] Built target lemon
make -f CMakeFiles/openshell.dir/build.make CMakeFiles/openshell.dir/depend
make[2]: Entering directory '/home/dac/ClionProjects/openshell'
cd /home/dac/ClionProjects/openshell && /usr/bin/cmake -E cmake_depends "Unix Makefiles" /home/dac/ClionProjects/openshell /home/dac/ClionProjects/openshell /home/dac/ClionProjects/openshell /home/dac/ClionProjects/openshell /home/dac/ClionProjects/openshell/CMakeFiles/openshell.dir/DependInfo.cmake --color=
Scanning dependencies of target openshell
make[2]: Leaving directory '/home/dac/ClionProjects/openshell'
make -f CMakeFiles/openshell.dir/build.make CMakeFiles/openshell.dir/build
make[2]: Entering directory '/home/dac/ClionProjects/openshell'
/usr/bin/cmake -E cmake_progress_report /home/dac/ClionProjects/openshell/CMakeFiles 2
[ 33%] Building C object CMakeFiles/openshell.dir/main.c.o
/usr/bin/cc   -Wall -Werror -O3 -std=c99 -I/usr/include/readline    -o CMakeFiles/openshell.dir/main.c.o   -c /home/dac/ClionProjects/openshell/main.c
Linking C executable openshell
/usr/bin/cmake -E cmake_link_script CMakeFiles/openshell.dir/link.txt --verbose=1
/usr/bin/cc   -Wall -Werror -O3 -std=c99   CMakeFiles/openshell.dir/main.c.o CMakeFiles/openshell.dir/errors.c.o CMakeFiles/openshell.dir/util.c.o CMakeFiles/openshell.dir/stack.c.o CMakeFiles/openshell.dir/flex/shellparser.c.o  -o openshell -rdynamic -lreadline 
CMakeFiles/openshell.dir/main.c.o: In function `main':
main.c:(.text.startup+0xef): undefined reference to `yylex_init'
main.c:(.text.startup+0x100): undefined reference to `yyset_in'
main.c:(.text.startup+0x12e): undefined reference to `yylex'
main.c:(.text.startup+0x13a): undefined reference to `yyget_text'
main.c:(.text.startup+0x178): undefined reference to `yylex_destroy'
collect2: error: ld returned 1 exit status
CMakeFiles/openshell.dir/build.make:188: recipe for target 'openshell' failed
make[2]: *** [openshell] Error 1
make[2]: Leaving directory '/home/dac/ClionProjects/openshell'
CMakeFiles/Makefile2:98: recipe for target 'CMakeFiles/openshell.dir/all' failed
make[1]: *** [CMakeFiles/openshell.dir/all] Error 2
make[1]: Leaving directory '/home/dac/ClionProjects/openshell'
Makefile:78: recipe for target 'all' failed
make: *** [all] Error 2

我的 CMake 构建文件是

cmake_minimum_required (VERSION 2.6)
project (openshell)
set(CMAKE_VERBOSE_MAKEFILE on)
include_directories(/usr/include/readline)

#### Lemon bootstrap ####
ADD_EXECUTABLE(lemon lemon.c)


file(GLOB SOURCES "./*.c")
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Werror -O3 -std=c99")
add_executable(openshell main.c openshell.h errors.c errors.h util.c util.h stack.c stack.h flex/shellparser.c flex/shellscanner.l flex/shellscanner.h)
target_link_libraries(openshell readline)

Answer 1

您没有链接 Flex 库，因此您使用的任何 Flex 函数都会出现链接器错误，例如 yyset_in。

您可以使用 find_package(FLEX) 并在使用 FLEX_TARGET 定义您的 Flex 目标后，您可以使用如下内容：

# Note: I use "ShellScanner" below as in FLEX_TARGET(ShellScanner flex/shellscanner.l ...)
add_executable(openshell
    ...
    flex/shellparser.c
    ${FLEX_ShellScanner_OUTPUTS}
)
target_link_libraries(openshell ${READLINE_LIBRARY} ${FLEX_LIBRARIES})

有关详细信息，请参阅 FindFLEX。

但是，我也没有看到 FindReadline.cmake module with the other modules that CMake provides by default, so you might have to create one yourself or use an existing one such as the one I just linked. There's also the Editline library, which provides similar functionality, and you can use an existing FindEditline.cmake 文件。

使用CMake构建错误

build error using CMake

c

cmake

lemon

flex-lexer