The # line Preprocessor Directive
The syntax of the line directive is as follows.
# line <constant> [<identifier>]
It causes the compiler to imagine-the line number of the next source line as given by <constant> and <identifier> gives the current input file. If <identifier> is absent, then the current file name remains unchanged.
Example
# line 15 pragma.c
INLINE DIRECTIVE
Reports to the compiler that the source code has in line asm statements. It is important to know that the source code contains an assembly code.
The # pragma Preprocessor Directive
The # pragma SAVEREGS
Guarantees that a huge function will not modify the value of any of the registers when it is entered. Place this directive immediately preceding the function's definition.
The #pragma DIRECTIVE
The ANSI-C and TURBO-C provide pragma directives. These #pragma directives are defined with # (hash) and these are the preprocessor directives. These directives deal with the formatting source which is listing and placing components in the object file generated by the compiler.
It sets/resets certain warnings and errors during the compilation of C program.