Stages

• preprocessing - Text substitution, stripping comments, and file inclusion.

g++ -E main.cpp -o main.i

• compilation - Compilation of the processed source code into assembly language.

g++ -S main.i -o main.s
# or
g++ -S main.cpp -o main.s

• assembler - Conversion of assembly code into machine code.

as main.s -o main.o
# or
g++ -c main.cpp -o main.o

• linker - Produce a single executable program file. It combines our program with startup code, such as the following:
  • Standard code at the beginning of the program to set up the running environment to pass command-line parameters and environmental variables.
  • Standard code at the end of the program to pass back a return code.

g++ main.cpp -o main

Flags

• -E Run the preprocessing stage.
• -S Run the preprocessing and compilation stages.
• -c Run the preprocessing, compilation, and assemble stages.
• -o file Write output to file.
• -llibrary, -l library Search the library named library when linking.
• -Idir Add dir to the list of directories to be searched for header files.
• -Ldir Add dir to the list of directories to be searched for -l.
• -Wall Enable all warnings about some constructions considered questionable by some users.
• -O Enable optimization.