1 files changed, 91 insertions, 0 deletions
diff --git a/cpp.c b/cpp.c
new file mode 100644
index 0000000..aeebaa8
--- /dev/null
+++ b/cpp.c
@@ -0,0 +1,91 @@
+#define _XOPEN_SOURCE 700
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+#include "cc.h"
+#include "cpp.h"
+
+static void dump(struct macro *list)
+{
+	for (struct macro *p = list; p != NULL; p = p->next) {
+		if (p->file) {
+			printf("%s:%ju: ", p->file, p->line);
+		} else if (p->line == 0) {
+			printf("<BUILTIN>: ");
+		} else {
+			printf("<COMMAND LINE>: ");
+		}
+		printf("'%s' => '%s'\n", p->identifier, p->replacement);
+	}
+}
+
+int preprocess(const char *in, const char *out, struct macro *predefined)
+{
+	(void)in; (void)out;
+		
+	time_t now = time(NULL);
+	struct tm *tm = localtime(&now);
+	char compiletime[16] = { 0 };
+	char compiledate[16] = { 0 };
+	strftime(compiletime, sizeof(compiletime), "%T", tm);
+	strftime(compiledate, sizeof(compiledate), "%b %e %Y", tm);
+
+	struct macro *perfile = define(NULL, NULL, 0, "__DATE__", compiledate);
+	define(perfile, NULL, 0, "__TIME__", compiletime);
+	define(perfile, NULL, 0, "__FILE__", in);
+	define(perfile, NULL, 0, "__LINE__", "0");
+
+	dump(predefined);
+	dump(perfile);
+
+	return 0;
+}
+
+static struct macro *do_define(struct macro *list, const char *file, uintmax_t line, const char *macro, const char *replacement)
+{
+	struct macro *def = list;
+
+	/* TODO: replace existing thing */
+	/* TODO: prevent redefining builtins */
+
+	if (def == NULL) {
+		def = calloc(1, sizeof(*def));
+		list = def;
+	} else {
+		while (def->next != NULL) {
+			def = def->next;
+		}
+		def->next = calloc(1, sizeof(*def));
+		def = def->next;
+	}
+
+	if (def == NULL) {
+		return NULL;
+	}
+
+	if (file) {
+		def->file = strdup(file);
+		if (file == NULL) {
+			return NULL;
+		}
+	}
+	def->line = line;
+	def->identifier = strdup(macro);
+	def->replacement = strdup(replacement);
+	if (def->identifier == NULL || def->replacement == NULL) {
+		return NULL;
+	}
+
+	return list;
+}
+
+struct macro *define(struct macro *list, const char *file, uintmax_t line, const char *macro, const char *replacement)
+{
+	list = do_define(list, file, line, macro, replacement);
+	if (list == NULL) {
+		error(file, line, "out of memory defining macro");
+	}
+	return list;
+}