Question

我正在运行macOS 10.14，并安装了bison的{{1}} 3.2版，但它拒绝链接：

brew

我的$ brew link bison --force Warning: Refusing to link macOS-provided software: bison If you need to have bison first in your PATH run: echo 'export PATH="/usr/local/opt/bison/bin:$PATH"' >> ~/.bash_profile For compilers to find bison you may need to set: export LDFLAGS="-L/usr/local/opt/bison/lib"有以下几行：

CMakeLists.txt

find_package(BISON 3.2 REQUIRED) ... message(STATUS "Found bison ${BISON_VERSION} at: ${BISON_EXECUTABLE}")失败，显示以下输出：

cmake

系统安装的Could NOT find BISON: Found unsuitable version "2.3", but required is at least "3.2" (found /usr/bin/bison)的版本为2.3，并且我知道Homebrew安装的版本为3.2。

bison模块显然使用了FindBISON CMake指令，并且我尝试将find_program添加到/usr/local/opt/bison/bin，但是总是首先选择CMAKE_PROGRAM_PATH否有什么关系。如何强制CMake支持Bison可执行文件的Homebrew安装版本？

Answer 1

由于macos系统中的某些内容取决于flex和bison的默认版本，因此它们安装在用户常规$PATH之外。解决方案是确保您（和您的用户）将程序的brew前缀添加到他们的路径（可以通过运行brew --prefix bison等找到）。解决此问题时，请务必清除CMake缓存，因为BISON_EXECUTABLE（等）已被缓存。

另一个“自动”选项是将此逻辑放入您的CMake文件中。几个开源项目就这样解决了。我可以找到的最早的修复程序示例来自this commit to STP（下面复制了基本部分）。

# On macOS, search Homebrew for keg-only versions of Bison and Flex. Xcode does
# not provide new enough versions for us to use.
if (CMAKE_HOST_SYSTEM_NAME MATCHES "Darwin")
    execute_process(
        COMMAND brew --prefix bison 
        RESULT_VARIABLE BREW_BISON
        OUTPUT_VARIABLE BREW_BISON_PREFIX
        OUTPUT_STRIP_TRAILING_WHITESPACE
    )
    if (BREW_BISON EQUAL 0 AND EXISTS "${BREW_BISON_PREFIX}")
        message(STATUS "Found Bison keg installed by Homebrew at ${BREW_BISON_PREFIX}")
        set(BISON_EXECUTABLE "${BREW_BISON_PREFIX}/bin/bison")
    endif()

    execute_process(
        COMMAND brew --prefix flex 
        RESULT_VARIABLE BREW_FLEX
        OUTPUT_VARIABLE BREW_FLEX_PREFIX
        OUTPUT_STRIP_TRAILING_WHITESPACE
    )
    if (BREW_FLEX EQUAL 0 AND EXISTS "${BREW_FLEX_PREFIX}")
        message(STATUS "Found Flex keg installed by Homebrew at ${BREW_FLEX_PREFIX}")
        set(FLEX_EXECUTABLE "${BREW_FLEX_PREFIX}/bin/flex")
    endif()
endif()

find_package(bison REQUIRED)
find_package(flex REQUIRED)

无法配置CMake来寻找Bison的Homebrew安装版本

1 个答案: