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#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include "lex.h"
#include "common.h"
#include "error.h"
#include "logic.h"
#include "gate.h"
/** Static defs **************************************************************/
static FILE* fd;
static struct token *cursor;
static const char *filename;
/** Helpers ******************************************************************/
#define EXPECT_AND_DISCARD_CRITICAL(type)\
do { \
EXPECT_CRITICAL(type) \
kerchunk(); \
} while (0);
#define EXPECT_CRITICAL(type)\
do { \
if (expect(type)) { \
return 1; \
} \
} while (0);
void
emit(const char *fmt, ...) {
va_list args;
va_start(args, fmt);
if (cursor) {
fprintf(stderr, "%s at (%zd,%zd): ", filename, cursor->loc.line, cursor->loc.column);
vfprintf(stderr, fmt, args);
indicate_file_area(fd, cursor->loc.line, cursor->loc.column - cursor->loc.leading_whitespace_len, cursor->span);
} else {
fprintf(stderr, "%s: ", filename);
vfprintf(stderr, fmt, args);
}
va_end(args);
}
static int
expect(enum TOKEN_TYPE e) {
const char *expected_desc = "(internal error)";
const char *observed_desc = "(internal error)";
if (!cursor || cursor->type != e) {
expected_desc = get_token_description(e);
if (cursor) {
observed_desc = get_token_description(cursor->type);
} else {
observed_desc = "end of file";
}
emit("Error: Expected %s, got %s\n", expected_desc, observed_desc);
return 1;
}
return 0;
}
static void
kerchunk() {
if (cursor) {
cursor = cursor->next;
}
}
/** Parsers ******************************************************************/
int
parse_bop(char *ident) {
char *l = NULL;
char *r = NULL;
EXPECT_CRITICAL(TOK_IDENT);
l = cursor->value;
kerchunk();
EXPECT_CRITICAL(TOK_IDENT);
r = cursor->value;
kerchunk();
return gate_add(cursor->type, ident, l, r);
}
int
parse_expr(void) {
char *ident = NULL;
EXPECT_AND_DISCARD_CRITICAL(TOK_EXPR);
EXPECT_CRITICAL(TOK_IDENT);
ident = cursor->value;
kerchunk();
EXPECT_AND_DISCARD_CRITICAL(TOK_COLON);
switch(cursor->type) {
/* FIXME do some things */
case TOK_OR : /* fallthrough */
case TOK_AND: /* fallthrough */
case TOK_XOR: /* fallthrough */
case TOK_NOR: /* fallthrough */
case TOK_NAND:
kerchunk();
parse_bop(ident);
break;
case TOK_NOT:
kerchunk();
EXPECT_AND_DISCARD_CRITICAL(TOK_IDENT); /* FIXME don't discard */
break;
default:
emit("Error: Unexpected %s\n", get_token_description(cursor->type));
return 1;
}
return 0;
}
int
parse(const char *fname, FILE *f, struct token *t) {
fd = f;
filename = fname;
cursor = t;
EXPECT_AND_DISCARD_CRITICAL(TOK_BEGIN);
/* Eat leading EOL tokens */
while (cursor && cursor->type == TOK_EOL) {
kerchunk();
}
EXPECT_AND_DISCARD_CRITICAL(TOK_MODULE);
EXPECT_CRITICAL(TOK_IDENT);
emit("Debug: module is named %s\n", cursor->value);
/* FIXME do something */
kerchunk();
EXPECT_AND_DISCARD_CRITICAL(TOK_EOL);
while (cursor) {
switch(cursor->type) {
case TOK_EOL:
kerchunk();
break;
case TOK_INPUT:
kerchunk();
expect(TOK_IDENT);
gate_input_add(cursor->value);
kerchunk();
break;
case TOK_EXPR:
if (parse_expr()) {
return 1;
}
break;
default:
emit("Error: Unexpected %s\n", get_token_description(cursor->type));
return 1;
}
}
return 0;
}
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