Pragmas control the compiler, i.e. they are compiler directives.
Syntax: pragma Name (Parameter_List);
where the parameter list is optional.
There are language-defined pragmas that give instructions for optimization, listing control, etc. An implementation may support additional (implementation-defined) pragmas.
Examples:
pragma List(Off); -- turn off listing generation
pragma Optimize(Off); -- turn off optional optimizations
pragma Inline(Set_Mask); -- generate code for Set_Mask inline
pragma Import(C, Put_Char, External_Name => "putchar"); -- import C putchar function
pragma PACK (SENSOR_WORD_FORMAT);