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 like the following ones
  • 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 the warnings about some constructions considered questionable by some users
• -O enable optimization