What are GCC passes and called programs?

Question

Another question arose : what programs and parts is invoked by gcc (especially when compiling C or C++ ) so that someone can develop some scheme for intercepting and modifying the stream for various custom encoding purposes?

Answer 1

Compilers are the “compiler driver” (ie gcc ) and the compiler itself, which also doubles as a preprocessor ( cc1 or cc1plus ). It also calls assembler ( as ) and linker ( ld ). In addition, there is a tool called collect2 that helps in the communication process in some cases.

If you want to see which intermediate states and calls will do this:

 gcc -save-temps -v ..... 

If you want to view compiler optimization omissions, use the following options:

 gcc -fdump-tree-all -fdump-rtl-all .... 

This creates (indefinitely) human-readable dumps of the internal state for debugging purposes. It was not possible to save anything and reload into the compiler later, it is accurate, but useful if you plan to change the source of the compiler or write a GCC plugin.

Answer 2

Pay attention to which programs cause:

 gcc -v main.c 

The exact steps are determined by a specification file with the format: https://gcc.gnu.org/onlinedocs/gcc-4.8.1/gcc/Spec-Files.html

View the default value (hardcoded in GCC):

 gcc -dumpspecs 

Run your own default specification file:

 gcc -specs=file