4 steps to achieve gcc compiler

Step 4 gcc compiler

• Pretreatment (hollo.c-> hello.i)

   gcc -E

  • Expand macros, header files

  • Replace compile condition

  • Delete comments, blank lines, blank

• Compile (hello.i-> hello.s)

  gcc  -S

  • Check the syntax specification
  • The most time-consuming, most system resources

• Compilation (hello.s-> hello.o)

  gcc -c

  • The assembly instructions translated into machine instructions

• Link (hello.o-> a.out)

  • The combined data segment
  • Address backfill

Some methods of GCC

parameter	effect	Case
-I	Uppercase I, you can specify the header file path	gcc -I ./inc hello.c -o hello
-O	Lowercase o, can be directly translated into the document file may be performed .exe / .out	gcc hello.c -o hello.out
-c	Lowercase C, only pre-compiler, assembler, compiled into a binary file .o	gcc hello.c -c
-g	Lowercase g, add debug file when compiling	gcc hello.c -o hello -g
-On	Capital O, need to be optimized to keep the numerical optimization, such as O1, O2, O3, the default level is 2, the range of 0 to 3, n ranges from greater better optimization	gcc hello.c -o hello -O3
-Wall	Wall, may prompt more warnings	gcc hello.c -o hello -Wall
-D	Macros can be specified at compile time, dynamic registration macro	gcc hello.c -D hello