GCC Compiler

  

Compiler Option

• -I 

• Alphabet I

• Used to specify the location where to search for the header files

• -l

• Alphabet L

• Used to specify the library to be linked with the code.

• -Wall

• Display all the warnings in the program

• To enable the Debugging symbol table

• gcc  -g hello.c –o hello

• To display all the warnings in the program

• gcc –Wall hello.c 

• To make all the warnings as error

• gcc –Werror –Wall hello.c

• To use the compile time macors using –D option

• gcc –DMY_MACRO main.c –o main

• To interpret char as unsigned char

• gcc –funsigned-char main.c –o main

• To interpret char as signed char

• gcc –fsigned-char main.c –o main

• Only compile the code, instead of linking

• gcc –C main.c

• To produce the assembly code of program

• gcc  -S main.c > main.s

• To generate the optimized code

• gcc  -O main.c –o main.o  

• To save all the intermediate files. For example, if you want to see the file after pre-processing, you have to see filename.i file.

• Gcc –save-temps  macro.c –o macro

Math library

• If you are getting error during the inclusion of math library,  you have to include that during the compilation.

• gcc test.c –lm (or)    gcc test.c -lmath

• option –lm will link the math library by the linker.

Segmentation fault

• It is raised, when there is uninitialized memory.

• In file operation, if you are closing the file, without opening the file, you will get segmentation fault.

• In scanf, if you are not using the ‘&’ operator for the address of the variable, segmentation fault occurs.

• In Scanf, if you are giving ‘\n’ inside the double quotes, you will get the segmentation fault.

In Array Initialization, if you are not proper value and accessing it, you will get the segmentation fault. For example, int arr[i] , you have to give the specific value to i. i.e int arr[3].