如何在CMake中为Gambit Scheme自定义编译器添加额外编译步骤

I’ve dealt with similar headaches when hooking non-standard compilers into CMake—its built-in compiler modules are tailored for traditional C/C++ workflows, so they don’t play nicely with Gambit’s unique multi-file pipeline. Here’s a practical, reliable way to replicate your manual compilation steps in CMake, ensuring the link file generation and object compilation run once in the correct order:

Step 1: Compile Scheme Sources to C Files #

First, we’ll handle converting each Scheme source to a C file individually, replacing the single-file behavior of CMAKE_Gambit_COMPILE_OBJECT with explicit per-source control:

# List all your Scheme source files
set(SCHEME_SOURCES factmodule.scm main.scm)

# Generate C files from each Scheme source
set(GENERATED_C_SOURCES "")
foreach(SRC_FILE ${SCHEME_SOURCES})
  get_filename_component(C_FILE ${SRC_FILE} NAME_WE)
  set(C_FILE "${C_FILE}.c")
  
  add_custom_command(
    OUTPUT ${C_FILE}
    COMMAND gambitc -c ${SRC_FILE}
    DEPENDS ${SRC_FILE}
    COMMENT "Compiling Scheme source ${SRC_FILE} to C"
  )
  
  list(APPEND GENERATED_C_SOURCES ${C_FILE})
endforeach()

Step 2: Generate the Gambit Link File #

Next, add a custom command to create link_file.c. This step will only run once all initial C files are ready, thanks to the dependency on GENERATED_C_SOURCES:

add_custom_command(
  OUTPUT link_file.c
  COMMAND gambitc -o link_file.c -link ${GENERATED_C_SOURCES}
  DEPENDS ${GENERATED_C_SOURCES}
  COMMENT "Generating Gambit link file"
)

# Add the link file to our list of C sources to compile
list(APPEND GENERATED_C_SOURCES link_file.c)

Step 3: Compile All C Files to Object Files #

Now compile every generated C file (including the link file) into object files, mirroring your manual workflow:

set(GENERATED_OBJS "")
foreach(C_FILE ${GENERATED_C_SOURCES})
  get_filename_component(OBJ_FILE ${C_FILE} NAME_WE)
  set(OBJ_FILE "${OBJ_FILE}.o")
  
  add_custom_command(
    OUTPUT ${OBJ_FILE}
    COMMAND gambitc -obj ${C_FILE}
    DEPENDS ${C_FILE}
    COMMENT "Compiling C source ${C_FILE} to object"
  )
  
  list(APPEND GENERATED_OBJS ${OBJ_FILE})
endforeach()

Step 4: Link the Final Executable #

Finally, create a custom target to link all object files into your executable. CMake will automatically ensure this step runs only after all object files are ready:

add_custom_target(myexec ALL
  COMMAND gcc -o myexec ${GENERATED_OBJS} -lgambit
  DEPENDS ${GENERATED_OBJS}
  COMMENT "Linking final executable 'myexec'"
)

Why This Solves Your Issues #

• Correct Ordering: Each custom command explicitly depends on its inputs, so CMake enforces the workflow you need: Scheme → C files → link file → object files → executable.
• Single Execution: The link file generation and object compilation steps only run once (or when their dependencies change), avoiding the per-file repetition from CMAKE_Gambit_COMPILE_OBJECT.
• Flexibility: This approach doesn’t force Gambit into CMake’s standard compiler model—perfect, since Gambit’s multi-file process deviates from typical C/C++ compilation.

If you want to reuse this logic, you can wrap these steps into a function inside your CMakeGambitInformation.cmake module, accepting a target name and source list as parameters.

内容的提问来源于stack exchange，提问作者koalag