igen: Start work on writing an instruction handler

generator.

This will make it easier in the long run to modify
instructions, add new instructions, and move the opcode
tables around.

1 files changed, 77 insertions, 0 deletions

diff --git a/igen/misc.c b/igen/misc.c
new file mode 100644
index 0000000..ba8c755
--- /dev/null
+++ b/igen/misc.c
@@ -0,0 +1,77 @@
+#include <ctype.h>
+#include <string.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "misc.h"
+
+char *read_file(const char *filename, long *size) {
+	/* Open the file. */
+	FILE *fp = fopen(filename, "r");
+	/* Size of the file, in bytes. */
+	long filesize = 0;
+	/* Buffer of the file contents. */
+	char *buf;
+
+	/* Return NULL, if we couldn't open the file. */
+	if (fp == NULL) {
+		return NULL;
+	}
+
+	/* Return NULL, if we couldn't seek to the end of the file. */
+	if (fseek(fp, 0L, SEEK_END)) {
+		fclose(fp);
+		return NULL;
+	}
+
+	/* Get the size of the file, in bytes. */
+	filesize = ftell(fp);
+
+	/* Return NULL, if the returned size is negative. */
+	if (filesize < 0) {
+		fclose(fp);
+		return NULL;
+	}
+
+	/* Allocate enough space for the entire file, plus one. */
+	buf = calloc(filesize+1, sizeof(char));
+
+	/* Return NULL, if the buffer wasn't allocated. */
+	if (buf == NULL) {
+		fclose(fp);
+		return NULL;
+	}
+
+	/* Seek back to the start of the file. */
+	rewind(fp);
+	/* Read the entire file contents into the buffer. */
+	fread(buf, sizeof(char), filesize, fp);
+	/* Close the file. */
+	fclose(fp);
+
+	/* Return the filesize, in bytes. */
+	*size = filesize;
+	/* Return the buffer. */
+	return buf;
+}
+
+char *get_line(char **str) {
+	char *s;
+	size_t i;
+	char *tmp = *str;
+
+	for (i = 0; tmp[i] != '\n' && tmp[i] != '\0'; i++);
+
+	s = calloc(i+1, sizeof(char));
+	memcpy(s, *str, i);
+
+	*str += (i+1);
+	return s;
+}
+
+char *make_str(const char *str) {
+	const size_t length = strlen(str);
+	char *s = calloc(length+1, sizeof(char));
+	memcpy(s, str, length+1);
+	return s;
+}