Better concat that doesn't need a size argument

4 files changed, 31 insertions, 11 deletions

diff --git a/src/build.c b/src/build.c
index f39b0e0..ca0c74e 100644
--- a/src/build.c
+++ b/src/build.c
@@ -65,7 +65,7 @@ static bool run_doscript(const char *doscript, const char *target) {
 	printf("\033[32mredo  \033[1m\033[37m%s\033[0m\n", reltarget);
 	free(reltarget);
 
-	char *temp_output = concat(2, target, ".redoing.tmp");
+	char *temp_output = concat(target, ".redoing.tmp");
 
 	pid_t pid = fork();
 	if (pid == -1) {
@@ -150,7 +150,7 @@ int rebuild(dep_info *dep) {
 	if (remove(dep->path) && errno != ENOENT)
 		fatal("redo: failed to remove %s", dep->path);
 
-	char *prereq = concat(2, dep->path, ".prereq");
+	char *prereq = concat(dep->path, ".prereq");
 	if (remove(prereq) && errno != ENOENT)
 		fatal("redo: failed to remove %s", prereq);
 
@@ -268,11 +268,11 @@ static char **parsecmd(char *cmd, size_t *i, size_t keep_free) {
 static do_attr *get_doscripts(const char *target) {
 	do_attr *ds = xmalloc(sizeof(do_attr));
 
-	ds->specific = concat(2, target, ".do");
+	ds->specific = concat(target, ".do");
 	char *dirc = xstrdup(target);
 	char *dt = dirname(dirc);
 
-	ds->general = concat(4, dt, "/default", take_extension(target), ".do");
+	ds->general = concat(dt, "/default", take_extension(target), ".do");
 	free(dirc);
 
 	if (fexists(ds->specific))
@@ -301,7 +301,7 @@ static char *xrealpath(const char *path) {
 
 	char *abstarget = NULL;
 	if (absdir)
-		abstarget = concat(3, absdir, "/", xbasename(path));
+		abstarget = concat(absdir, "/", xbasename(path));
 
 	free(dirc);
 	free(absdir);
@@ -332,7 +332,7 @@ static char *get_dep_path(const char *target) {
 	char *reltarget = get_relpath(target);
 
 	char *redodir = is_absolute(reltarget) ? "/.redo/abs/" : "/.redo/rel/";
-	dep_path = concat(3, root, redodir, reltarget);
+	dep_path = concat(root, redodir, reltarget);
 
 	/* create directory */
 	mkpath(dep_path, 0755); /* TODO: should probably be somewhere else */
@@ -351,7 +351,7 @@ static char *get_dep_path(const char *target) {
 void add_prereq(const char *target, const char *parent, int ident) {
 	char *base_path = get_dep_path(parent);
 
-	char *dep_path = concat(2, base_path, ".prereq");
+	char *dep_path = concat(base_path, ".prereq");
 
 	int fd = open(dep_path, O_WRONLY | O_APPEND | O_CREAT, 0644);
 	if (fd < 0)
@@ -553,7 +553,7 @@ static int handle_c(dep_info *dep) {
 	}
 
 	/* make sure all prereq dependencies are met */
-	char *prereq_path = concat(2, dep->path, ".prereq");
+	char *prereq_path = concat(dep->path, ".prereq");
 	FILE *prereqfd = fopen(prereq_path, "rb");
 	if (!prereqfd) {
 		if (errno != ENOENT)
diff --git a/src/filepath.c b/src/filepath.c
index b752e08..2f175ef 100644
--- a/src/filepath.c
+++ b/src/filepath.c
@@ -129,7 +129,7 @@ void mkpath(char *path, mode_t mode) {
 /* Make path absolute by prepending root, if path isn't already absolute. */
 char *make_abs(char *root, char *path) {
 	if (!is_absolute(path))
-		return concat(3, root, "/", path);
+		return concat(root, "/", path);
 	else
 		return xstrdup(path);
 }
diff --git a/src/util.c b/src/util.c
index 266cf90..d99e952 100644
--- a/src/util.c
+++ b/src/util.c
@@ -59,7 +59,7 @@ char *xstrdup(const char *str) {
 }
 
 /* For concating multiple strings into a single larger one. */
-char *concat(size_t count, ...) {
+char *concat_(size_t count, ...) {
 	assert(count > 0);
 	va_list ap, ap2;
 	va_start(ap, count);
diff --git a/src/util.h b/src/util.h
index 64b39e3..278d809 100644
--- a/src/util.h
+++ b/src/util.h
@@ -17,10 +17,30 @@ extern void __attribute__((noreturn)) die_(const char *err, ...);
 extern void *xmalloc(size_t size);
 extern void *xrealloc(void *ptr, size_t size);
 extern char *xstrdup(const char *str);
-extern char *concat(size_t count, ...);
 extern unsigned char *hash_file(FILE *fp);
 extern void sha1_to_hex(const unsigned char *sha1, char *buf);
 extern void hex_to_sha1(const char *s, unsigned char *sha1);
 extern uint32_t generate_seed();
 
+/* crazy macros for returning the number of arguments in __VA_ARGS__ */
+/* See https://stackoverflow.com/questions/2308243/ */
+#define PP_NARG(...) __PP_NARG(__VA_ARGS__, __PP_RSEQ_N())
+#define __PP_NARG(...) __PP_ARG_N(__VA_ARGS__)
+#define __PP_ARG_N(_1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _13,     \
+                   _14, _15, _16, _17, _18, _19, _20, _21, _22, _23, _24, _25, \
+                   _26, _27, _28, _29, _30, _31, _32, _33, _34, _35, _36, _37, \
+                   _38, _39, _40, _41, _42, _43, _44, _45, _46, _47, _48, _49, \
+                   _50, _51, _52, _53, _54, _55, _56, _57, _58, _59, _60, _61, \
+                   _62, _63, N, ...) N
+
+#define __PP_RSEQ_N()                                                          \
+	63, 62, 61, 60, 59, 58, 57, 56, 55, 54, 53, 52, 51, 50, 49, 48, 47,    \
+	        46, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 33, 32,    \
+	        31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17,    \
+	        16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0
+
+#define concat(...) concat_(PP_NARG(__VA_ARGS__), __VA_ARGS__)
+
+extern char *concat_(size_t count, ...);
+
 #endif