用 clang 和 gfortran 编译

Question

我正在尝试编译一个我最近开始工作的项目，并被要求在 clang 而不是 gcc 中编译代码。该项目有一个 CMake 文件，我尝试使用

cmake -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ ../src

但是抛出了一个错误，我认为这是因为 clang 没有 Fortran 编译器，并且项目的一部分有 Fortran 代码。有没有办法让它在编译 Fortran 代码时使用 gfortran（以前在使用 gcc 时使用），其余部分使用 clang/clang++？

我认为相关的 cmake 文件部分是：

enable_language(Fortran)

string(REGEX MATCH gfortran HAVE_GFORTRAN ${CMAKE_Fortran_COMPILER})
string(REGEX MATCH xlf HAVE_XLF ${CMAKE_Fortran_COMPILER})
string(REGEX MATCH pg77 HAVE_PG77 ${CMAKE_Fortran_COMPILER})
string(REGEX MATCH g77 HAVE_G77 ${CMAKE_Fortran_COMPILER})
string(REGEX MATCH ifort HAVE_ifORT ${CMAKE_Fortran_COMPILER})
string(REGEX MATCH f77 HAVE_F77 ${CMAKE_Fortran_COMPILER})

if(HAVE_GFORTRAN)
  set(F_LIBRARY gfortran CACHE string "fortran library")
  find_library(F_LIBRARY NAMES gfortran)
  set(FORTRAN_UNDERSCORE end CACHE string "What type of fortran underscore style - linux,end,none")
  set(DEF_FORTRAN_UNDERSCORE "#define FORTRAN_UNDERSCORE_END")
elseif(HAVE_XLF)
  set(F_LIBRARY xlf90 CACHE string "fortran library")
  find_library(F_LIBRARY NAMES xlf90)
  set(FORTRAN_UNDERSCORE none CACHE string "What type of fortran underscore style - linux,end,none")
  set(DEF_FORTRAN_UNDERSCORE "#define FORTRAN_UNDERSCORE_NONE")
elseif(HAVE_PGF77)
  set(F_LIBRARY pgftnrtl CACHE string "fortran library")
  find_library(F_LIBRARY NAMES pgftnrtl)
  set(FORTRAN_UNDERSCORE end CACHE string "What type of fortran underscore style - linux,end,none")
  set(DEF_FORTRAN_UNDERSCORE "#define FORTRAN_UNDERSCORE_END")
elseif(HAVE_G77)
  set(F_LIBRARY g2c CACHE string "fortran library")
  find_library(F_LIBRARY NAMES g2c)
  set(FORTRAN_UNDERSCORE linux CACHE string "What type of fortran underscore style - linux,end,none")
  set(DEF_FORTRAN_UNDERSCORE "#define FORTRAN_UNDERSCORE_LINUX")
elseif(HAVE_ifort)
  set(F_LIBRARY ifcore CACHE string "fortran library")
  find_library(F_LIBRARY NAMES ifcore)
  set(FORTRAN_UNDERSCORE end CACHE string "What type of fortran underscore style - linux,end,none")
  set(DEF_FORTRAN_UNDERSCORE "#define FORTRAN_UNDERSCORE_END")
elseif(HAVE_F77)
  set(FORTRAN_UNDERSCORE end CACHE string "What type of fortran underscore style - linux,end,none")
  set(FORTRAN_LIBRARY "" CACHE string "fortran library")
  set(DEF_FORTRAN_UNDERSCORE "#define FORTRAN_UNDERSCORE_END")
endif()

# f77 on redstorm currently an exception - doesn't need it 
if(NOT F_LIBRARY AND NOT HAVE_F77)
  message(FATAL_ERROR "Cannot find fortran library")
endif(NOT F_LIBRARY AND NOT HAVE_F77)

终端输出说当我尝试 cmake 时会抛出一个错误：

message(FATAL_ERROR "Cannot find fortran library")

如果我需要发布更多信息，请告诉我。提前谢谢了！

Answer 1

为了不让问题悬而未决：

如果 cmake 无法自动确定该变量，则CMAKE_Fortran_COMPILER必须将其设置为编译器可执行文件 ( gfortran)的名称。