shithub: rgbds

ref: d517d2d6b48ef4a10c2ac1c86b54b62275ff3ec8
dir: /src/asm/macro.c/

#include <assert.h>
#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "asm/asm.h"
#include "asm/macro.h"
#include "asm/warning.h"

/*
 * Your average macro invocation does not go past the tens, but some go further
 * This ensures that sane and slightly insane invocations suffer no penalties,
 * and the rest is insane and thus will assume responsibility.
 * Additionally, ~300 bytes (on x64) of memory per level of nesting has been
 * deemed reasonable. (Halve that on x86.)
 */
#define INITIAL_ARG_SIZE 32
struct MacroArgs {
	unsigned int nbArgs;
	unsigned int shift;
	unsigned int capacity;
	char *args[];
};

#define SIZEOF_ARGS(nbArgs) (sizeof(struct MacroArgs) + \
			    sizeof(((struct MacroArgs){0}).args[0]) * (nbArgs))

static struct MacroArgs *macroArgs = NULL;
static uint32_t uniqueID = -1;
/*
 * The initialization is somewhat harmful, since it is never used, but it
 * guarantees the size of the buffer will be correct. I was unable to find a
 * better solution, but if you have one, please feel free!
 */
static char uniqueIDBuf[] = "_" EXPAND_AND_STR(UINT32_MAX);
static char *uniqueIDPtr = NULL;

struct MacroArgs *macro_GetCurrentArgs(void)
{
	return macroArgs;
}

struct MacroArgs *macro_NewArgs(void)
{
	struct MacroArgs *args = malloc(SIZEOF_ARGS(INITIAL_ARG_SIZE));

	args->nbArgs = 0;
	args->shift = 0;
	args->capacity = INITIAL_ARG_SIZE;
	return args;
}

void macro_AppendArg(struct MacroArgs **args, char *s)
{
	if ((**args).nbArgs == MAXMACROARGS)
		yyerror("A maximum of " EXPAND_AND_STR(MAXMACROARGS)
			" arguments is allowed");
	if ((**args).nbArgs == (**args).capacity) {
		(**args).capacity *= 2;
		*args = realloc(*args, SIZEOF_ARGS((**args).capacity));
	}
	(**args).args[(**args).nbArgs++] = s;
}

void macro_UseNewArgs(struct MacroArgs *args)
{
	macroArgs = args;
}

void macro_FreeArgs(struct MacroArgs *args)
{
	for (uint32_t i = 0; i < macroArgs->nbArgs; i++)
		free(args->args[i]);
}

char const *macro_GetArg(uint32_t i)
{
	uint32_t realIndex = i + macroArgs->shift - 1;

	return realIndex >= macroArgs->nbArgs ? NULL
					      : macroArgs->args[realIndex];
}

uint32_t macro_GetUniqueID(void)
{
	return uniqueID;
}

char const *macro_GetUniqueIDStr(void)
{
	return uniqueIDPtr;
}

void macro_SetUniqueID(uint32_t id)
{
	uniqueID = id;
	if (id == -1) {
		uniqueIDPtr = NULL;
	} else {
		/* The buffer is guaranteed to be the correct size */
		sprintf(uniqueIDBuf, "_%" PRIu32, id);
		uniqueIDPtr = uniqueIDBuf;
	}
}

void macro_ShiftCurrentArgs(void)
{
	if (macroArgs->shift != macroArgs->nbArgs)
		macroArgs->shift++;
}

uint32_t macro_NbArgs(void)
{
	return macroArgs->nbArgs - macroArgs->shift;
}