Include files at compile time in C

incl_hello.txt

Hello, world!
This file ends with a null character: 

incl_message.txt

No null termination here - these are just bytes.

include_file.h

static inline
size_t
included_length_raw(const char *s, const char *e)
{
	return e - s;
}

static inline
const unsigned char *
included_bytes_raw(const char *s, const char *e)
{
	return s;
}

static inline
const char *
included_string_raw(const char *s, const char *e)
{
	assert(e[-1] == '\0' || s < e - 1 && e[-2] == '\0');
	return s;
}

#define include_file(X) \
	extern const char _binary_##X##_start[], _binary_##X##_end[]

#define included_length(X) \
	included_length_raw(_binary_##X##_start, _binary_##X##_end)

#define included_bytes(X) \
	included_bytes_raw(_binary_##X##_start, _binary_##X##_end)

#define included_string(X) \
	included_string_raw(_binary_##X##_start, _binary_##X##_end)

main.c

#include <stdio.h>
#include <assert.h>

#include "include_file.h"

include_file(incl_hello_txt);
include_file(incl_message_txt);

int
main(void)
{
	printf("Hello: \"%s\"\n", included_string(incl_hello_txt));

	printf("Message: \"");
	fwrite(included_bytes(incl_message_txt), 1,
		included_length(incl_message_txt), stdout);
	printf("\"\n");

	printf("This will fail due to the assertion failing: %s",
		included_string(incl_message_txt));
}

Makefile

.PHONY: test
test: main
	./$<

main: main.o incl_hello.o incl_message.o
main.o: main.c include_file.h

incl_%.o: incl_%.txt
	@# If you always want to use includes as strings, you can check that
	@# they are null-terminated at compile-time:
	@# grep -qPa '\x00' $<
	ld -z noexecstack -r -b binary -o $@ $<

.PHONY: clean
clean:
	rm -f *.o main

Hello: "Hello, world!
This file ends with a null character: "
Message: "No null termination here - these are just bytes.
"
main: include_file.h:19: included_string_raw: Assertion `e[-1] == '\0' || s < e - 1 && e[-2] == '\0'' failed.