This is sometimes referred to as a significant comment. The intention is that of passing directives to the compiler or the preprocessor at various points in the source program. Such directives might indicate whether speed or space is more important, or if certain checks should be suppressed, or if a particular routine is to be timed, etc.
An instruction to the compiler to compile your program in a certain way. For example, you can use pragmas to insert copyright information into your object files, to specify a particular template instantiation, and to specify optimization levels.
a command that you can give to a particular compiler, but which will be ignored by other compilers
a description that is dependent on language processing system and that gives some information to the compiler
a hint to a compiler, telling it something about the code
a hint to the compiler, which can be ignored if the compiler doesn't understand it (handy for cross-platform code)
a module that affects the compilation phase of your program as well as the execution phase
an implementation-defined instruction to the compiler
an instruction to the Oracle compiler that tells it to do something
an instruction to your compiler to perform some particular action at compile time
a special kind of module that affects the compilation phase of your program
a special module that acts as directive to the compiler to alter how Perl compiles your code
a suggestion to the compiler and can be ignored by any implementation according to the definition of Ada
A pragma is a compiler directive. There are language-defined pragmas that give instructions for optimization, listing control, etc. An implementation may support additional (implementation-defined) pragmas. (28)
A C directive for controlling the compilation of source.
A pragma conveys information to the compiler.
A preprocessor directive that is not specified by the ANSI standard. Pragmas often control actions of the compiler and linker. A pragma always begins with a number sign (#).
In J2SE v.1.2, a directive to the idltojava compiler to perform certain operations while compiling an IDL file. For example, the pragma "javaPackage" directs the idltojava compiler to put the Java programming language interfaces and classes it generates from the IDL interface into the Java programming language package specified. In J2SE v.1.3 and higher, this functionality is supported via the -pkgPrefix command line option to idlj.