问题
Is it possible to expand out #include lines of a c++ file, probably using the C preprocessor, such that I can read an extended file without #includes, but instead with the files that are #included?
To be concrete, if I have
fileA.cpp:
#include "fileB.H"
int main()
{
//do whatever
return(0);
}
fileB.H:
#include "fileC.H"
//Some lines of code
fileC.H
//Some other lines of code
And output:
//Some other lines of code
//Some lines of code
int main()
{
//do whatever
return(0);
}
Essentially, copy-pasting the files that are included into one large text/C++ code file, without compiling?
If I run the cpp with relevant -I<Directory containing files to include> then I get a long text file, but rather than just code, it gives what would be passed to the compiler (duh!)
回答1:
For gcc and clang, you can use the -E option (see similar answer) to output the preprocessor output without compiling.
To also show comments like in your sample output, you can add in the -CC and -P flags:
clang++ -E -CC -P fileA.cpp
All of the processor options for -E can be found on here, on gcc.gnu.org.
-CC Do not discard comments, including during macro expansion. This is like -C, except that comments contained within macros are also passed through to the output file where the macro is expanded.
-P Inhibit generation of linemarkers in the output from the preprocessor. This might be useful when running the preprocessor on something that is not C code, and will be sent to a program which might be confused by the linemarkers.
For the Visual C++ compiler, you can use /E. See this SO answer.
来源：https://stackoverflow.com/questions/21670816/expand-includes-to-a-text-file-for-c