Introduce ctl::set and ctl::map

We now have a C++ red-black tree implementation that implements standard
template library compatible APIs while compiling 10x faster than libcxx.
It's not as beautiful as the red-black tree implementation in Plinko but
this will get the job done and the test proves it upholds all invariants

This change also restores CheckForMemoryLeaks() support and fixes a real
actual bug I discovered with Doug Lea's dlmalloc_inspect_all() function.

libc/mem/leaks.c

@@ -0,0 +1,94 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8                               :vi │
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2021 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/cxxabi.h"
+#include "libc/intrin/cxaatexit.internal.h"
+#include "libc/intrin/dll.h"
+#include "libc/intrin/kprintf.h"
+#include "libc/intrin/weaken.h"
+#include "libc/mem/mem.h"
+#include "libc/nt/typedef/imagetlscallback.h"
+#include "libc/runtime/runtime.h"
+#include "libc/thread/posixthread.internal.h"
+#include "libc/thread/thread.h"
+
+#define LEAK_CONTAINER(e) DLL_CONTAINER(struct Leak, elem, e)
+
+struct Leak {
+  void *alloc;
+  struct Dll elem;
+};
+
+static int leak_count;
+static struct Dll *leaks;
+static struct Dll *freaks;
+static pthread_mutex_t lock;
+
+void __may_leak(void *alloc) {
+  if (!alloc)
+    return;
+  pthread_mutex_lock(&lock);
+  if (dll_is_empty(freaks)) {
+    int g = __granularity();
+    struct Leak *p = _mapanon(g);
+    int n = g / sizeof(struct Leak);
+    for (int i = 0; i < n; ++i) {
+      dll_init(&p[i].elem);
+      dll_make_first(&freaks, &p[i].elem);
+    }
+  }
+  struct Dll *e = dll_first(freaks);
+  LEAK_CONTAINER(e)->alloc = alloc;
+  dll_remove(&freaks, e);
+  dll_make_first(&leaks, e);
+  pthread_mutex_unlock(&lock);
+}
+
+static void visitor(void *start, void *end, size_t used_bytes, void *arg) {
+  if (!used_bytes)
+    return;
+  for (struct Dll *e = dll_first(leaks); e; e = dll_next(leaks, e))
+    if (start == LEAK_CONTAINER(e)->alloc)
+      return;
+  kprintf("error: leaked %'zu byte allocation at %p\n", used_bytes, start);
+  ++leak_count;
+}
+
+/**
+ * Tests for memory leaks.
+ */
+void CheckForMemoryLeaks(void) {
+
+  // validate usage of this api
+  if (_weaken(_pthread_decimate))
+    _weaken(_pthread_decimate)();
+  if (!pthread_orphan_np())
+    kprintf("warning: called CheckForMemoryLeaks() from non-orphaned thread\n");
+
+  // call dynamic global destructors
+  __cxa_thread_finalize();
+  __cxa_finalize(0);
+
+  // check for leaks
+  malloc_inspect_all(visitor, 0);
+  if (leak_count) {
+    kprintf("loser: you forgot to call free %'d time%s\n", leak_count,
+            leak_count == 1 ? "" : "s");
+    _exit(73);
+  }
+}