What files are actually included when compiling

Question

I have a very large code, a lot of which is legacy code. I want to know which of all these files are taking part in the compilation. The code is written in GNU compilers and mostly in C/C++, but some in other programs too. Any advice will be highly appreciated.

Thanks,

Moshe.

I am compiling under linux with a mix of scripts/makefiles. I want to somehow 'wrap' this build with a tool which will give an output of all the source files used in the build, preferably with absolute path names.

What do you say?

Answer 1

If you want to show included headers then whether that's supported and how to do it depends on the compiler.

E.g.,

C:\test> (g++ --help --verbose 2>&1) | find "header"
  -print-sysroot-headers-suffix Display the sysroot suffix used to find headers
  --sysroot=<directory>    Use <directory> as the root directory for headers
  -H                          Print the name of header files as they are used
  -MG                         Treat missing header files as generated files
  -MM                         Like -M but ignore system header files
  -MMD                        Like -MD but ignore system header files
  -MP                         Generate phony targets for all headers
  -Wsystem-headers            Do not suppress warnings from system headers
  -print-objc-runtime-info    Generate C header of platform-specific features
  -ftree-ch                   Enable loop header copying on trees

C:\test> (cl /? 2>&1) | find "include"
/FI<file> name forced include file      /U<name> remove predefined macro
/u remove all predefined macros         /I<dir> add to include search path
/nologo suppress copyright message      /showIncludes show include file names

C:\test> _

In the above you can see the relevant options for respectively g++ and Visual C++.

Cheers & hth.,

– Alf