TITLE

embed.pod - Parrot embedding system

SYNOPSIS

#include "parrot/embed.h"

int main(int argc, char *argv[]) {
	Parrot_Interp interp;
	Parrot_PackFile pf;
	char *bcfile="program.pbc";

	argc--; argv++;	/* skip the program name */
	
	interp=Parrot_new();
	Parrot_init(interp);

	if(PARROT_JIT_CAPABLE) {
		Parrot_setflags(interp, PARROT_JIT_FLAG, NULL); /* activate JIT */
	}

	pf=Parrot_readbc(interp, bcfile);
	Parrot_loadbc(interp, pf);

	Parrot_runcode(interp, argc, argv);	/* argc and argv as seen by the bytecode file */

	Parrot_destroy(interp);
	
	return 0;
}

FILES

include/parrot/embed.h

embed.c

DESCRIPTION

Parrot's embedding system is designed with one guiding principle in mind: encapsulation. Users of Parrot shouldn't have to know what the insides of a Parrot_Interp structure look like or how to load a packfile. They should just know a few functions and constants. The embedding system is designed to do just that.

Data Structures

Parrot_Interp

This typedef represents (a pointer to) an actual Parrot interpreter.

Parrot_PackFile

This structure represents (a pointer to) a 'packfile'--a Parrot bytecode file.

Parrot_Interp_flag

An interpreter flag.

Parrot_Interp_flag_val

The value passed in with an interpreter flag. Unused at the moment--just pass in NULL.

Parrot_Int

Parrot_UInt

Parrot_Float

Parrot_Opcode

Various Parrot internal types; most are chosen at Configure time.

Constants

Interpreter flags:

PARROT_DEBUG_FLAG

This flag turns on debugging mode. Debugging mode basically means that Parrot's core prints out diagnostic messages. This flag does not take any parameters.

PARROT_TRACE_FLAG

This flag turns on opcode tracing. Parrot will print out each opcode and the parameters passed to it as it is called. This flag does not take any parameters.

PARROT_BOUNDS_FLAG

This flag turns on bounds checking. Parrot will make sure that all addresses returned by an opcode function are within the boundaries of the bytecode block. This flag does not take any parameters.

PARROT_PROFILE_FLAG

This flag turns on profiling. Parrot will print out a list of each opcode called, the number of times it was called, the average time it took to run, and the total time it took over the life of the program. This flag does not take any parameters.

PARROT_PREDEREF_FLAG

This flag turns on predereferencing. Parrot will transform many offsets in the opcode stream to absolute pointers. This flag does not take any parameters.

PARROT_JIT_FLAG

This flag turns on just-in-time compilation. Parrot will convert the bytecode file into native machine code and run it, usually resulting in substantial speedup. This flag does not take any parameters.

Other constants:

PARROT_VERSION

This constant contains a string representation of Parrot's version number.

PARROT_MAJOR_VERSION

This constant contains the first part of Parrot's version number.

PARROT_MINOR_VERSION

This constant contains the second part of Parrot's version number.

PARROT_PATCH_VERSION

This constant contains the third part of Parrot's version number.

PARROT_CONFIG_DATE

This constant contains the date that Configure was run to generate config.h.

PARROT_JIT_CAPABLE

This constant is true if Parrot supports JIT on this platform, false otherwise.

PARROT_ARCHNAME

This constant contains a string representation of the Parrot JIT's name for the current architecture.

PARROT_CPU_ARCH

This constant contains the name of your processor (as the JIT sees it).

PARROT_OS_NAME

This constant contains the name of your operating system (as the JIT sees it).

Functions

Parrot_Interp Parrot_new()

Allocates and returns a new Parrot interpreter.

void Parrot_init(Parrot_Interp)

Initializes a Parrot interpreter.

void Parrot_setflag(Parrot_Interp, Parrot_Interp_flag, Parrot_Interp_flag_val)

Sets a flag in the Parrot interpreter.

Parrot_PackFile Parrot_readbc(Parrot_Interp, char *filename)

Reads in a bytecode file and returns a packfile structure for it.

void Parrot_loadbc(Parrot_Interp, Parrot_PackFile)

Loads a packfile into a Parrot interpreter.

void Parrot_runcode(Parrot_Interp, int argc, char *argv[])

Runs the bytecode associated with a Parrot interpreter. argc and argv are the parameters the bytecode should receive.

Parrot_destroy(Parrot_Interp)

Deallocates all memory associated with a Parrot interpreter.

XXX At the moment, it just leaks most of it.

SEE ALSO

embed.c and embed.h for the implementation.

test_main.c for Parrot's use of the embedding system.