WIP: rewrite C++ backend to be CHEADmaster

+ C allows for a bit more control, and we can manually handle closure
  contexts. For example `examples/fib.fwd` now works for effectively any
  `n`, pretty cool.

+ Fairly slow Fibonacci, I must admit. Initial profiling indicates it's
  mainly due to branch mispredictions, but I'll have to look into this a
  bit deeper.

+ The code is a bit hacked together, for now I'm more interested in
  getting things working, I'll worry about making things pretty later.

+ For testing, there's also initial support for modules, just so I can
  print stuff to the terminal

+ This commit is way too big, lol

1 files changed, 66 insertions, 0 deletions

diff --git a/src/path.c b/src/path.c
new file mode 100644
index 0000000..87cd26b
--- /dev/null
+++ b/src/path.c
@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: copyleft-next-0.3.1 */
+/* Copyright 2023 Kim Kuparinen < kimi.h.kuparinen@gmail.com > */
+
+/**
+ * @file path.c
+ *
+ * Path handling helper implementations.
+ */
+
+#include <stddef.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <errno.h>
+
+#include <fwd/path.h>
+#include <fwd/debug.h>
+
+char *fwd_basename(const char *file)
+{
+	size_t l = strlen(file);
+	size_t n = l - 1;
+	while (--n) {
+		if (file[n] == '/')
+			break;
+	}
+
+	if (n == 0)
+		return strdup(file);
+
+	return strndup(file + n + 1, l - n);
+}
+
+char *fwd_dirname(const char *file)
+{
+	size_t l = strlen(file);
+	size_t n = l - 1;
+	while (--n) {
+		if (file[n] == '/')
+			break;
+	}
+
+	return strndup(file, n);
+}
+
+char *fwd_cwdname()
+{
+	size_t size;
+	long path_max = pathconf(".", _PC_PATH_MAX);
+	if (path_max == -1)
+		size = 1024;
+	else
+		size = (size_t)path_max;
+
+	char *buf = malloc(size);
+	if (!buf)
+		return NULL;
+
+	if (!getcwd(buf, size)) {
+		error("%s\n", strerror(errno));
+		free(buf);
+		return NULL;
+	}
+
+	return buf;
+}