add support for setting flags in source

1 files changed, 68 insertions, 0 deletions

diff --git a/flags.c b/flags.c
new file mode 100644
index 0000000..2cd7b13
--- /dev/null
+++ b/flags.c
@@ -0,0 +1,68 @@
+#define _XOPEN_SOURCE 700
+#include <fcntl.h>
+#include <regex.h>
+#include <sys/mman.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "maje.h"
+
+#define MAX_MATCHES (2)
+
+static struct majeflag * find_flags(const struct majefile *file, const regex_t * restrict re, struct majeflag *flags)
+{
+	int fd = open(file->path, O_RDONLY);
+	if (fd == -1) {
+		return NULL;
+	}
+
+	void *map = mmap(NULL, (size_t)file->st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+	if (map == MAP_FAILED) {
+		close(fd);
+		return NULL;
+	}
+
+	regmatch_t match[MAX_MATCHES];
+	
+	void *base = map;
+	while (regexec(re, base, MAX_MATCHES, match, 0) == 0) {
+		if (match[1].rm_so == -1) {
+			break;
+		}
+		char flag[FILENAME_MAX] = { 0 };
+		char *start = (char*)base + match[1].rm_so;
+		memcpy(flag, start, match[1].rm_eo - match[1].rm_so);
+		flags = insert_flag(flags, flag);
+		base = start + match[1].rm_eo;
+	}
+
+	munmap(map, file->st.st_size);
+	close(fd);
+
+	return flags;
+}
+
+struct majeflag *add_flags(const struct majefile *source, struct majeflag *flags)
+{
+	static regex_t re = { .re_nsub = (size_t)-1 };
+	if (re.re_nsub == (size_t)-1) {
+		if (regcomp(&re,
+			"(MAJE_[[:upper:]]+=[^[:space:]]+)",
+			REG_EXTENDED | REG_NEWLINE) != 0) {
+				fprintf(stderr, "maje: regcomp(MAJE) failed\n");
+				abort();
+		}
+	}
+
+	struct majeflag *ret = find_flags(source, &re, flags);
+
+	if (ret != NULL) {
+		while (ret->prev != NULL) {
+			ret = ret->prev;
+		}
+	}
+
+	return ret;
+}