Embed program source code (or any binary) in the output ELF.

Makefile

DEBUG=-ggdb

selfprint: selfprint.c.o selfprint.c
	$(CC) -o $@ $(DEBUG) $^

selfprint.c.o: selfprint.c
	objcopy -I binary -O elf64-x86-64 -B i386 $< $@

.PHONY: show
show: selfprint
	nm -S -t x $<

.PHONY: clean
clean:
	rm -f selfprint.c.o selfprint

selfprint.c

// vim: ts=2 sw=2 et:
// call as ./selfprint -v

#include <stdio.h>
#include <stdint.h>
#include <string.h>

#define ANSI_COLOR_GREEN   "\x1b[32m"
#define ANSI_COLOR_RESET   "\x1b[0m"

extern char _binary_selfprint_c_start[];
extern char _binary_selfprint_c_end[];
extern const void * _binary_selfprint_c_size;
#define BINARY_FILE_SIZE ((uintptr_t)&_binary_selfprint_c_size)

int main(int argc, char *argv[]) {
  printf("%p\n", _binary_selfprint_c_start);
  printf("size_addr: %p\n", &_binary_selfprint_c_size); // never produces correct result.
  printf("size_sym: %lx\n", BINARY_FILE_SIZE); // also wrong.
  printf("size_cal: %ld\n", &_binary_selfprint_c_end[0] - &_binary_selfprint_c_start[0]);
  fflush(stdout);

  if (argc >= 2 && !strcmp(argv[1], "-v")) {
    fwrite("\n", 1, 1, stdout);
    fwrite(ANSI_COLOR_GREEN, 1, strlen(ANSI_COLOR_GREEN), stdout);
    fwrite(_binary_selfprint_c_start, 1, &_binary_selfprint_c_end[0] - &_binary_selfprint_c_start[0], stdout);
    fwrite(ANSI_COLOR_RESET, 1, strlen(ANSI_COLOR_GREEN), stdout);
  }
  return 0;
}