text: /*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
  │vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
  ╞══════════════════════════════════════════════════════════════════════════════╡
  │ Copyright 2020 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/fmt/itoa.h"
  #include "libc/log/libfatal.internal.h"
  #include "libc/macros.internal.h"
  #include "libc/runtime/memtrack.internal.h"
  
  #define ADDR(x) ((intptr_t)((int64_t)((uint64_t)(x) << 32) >> 16))
  
  static bool IsNoteworthyHole(unsigned i, const struct MemoryIntervals *mm) {
    // gaps between shadow frames aren't interesting
    // the chasm from heap to stack ruins statistics
    return !(
        (IsArenaFrame(mm->p[i].y) && !IsArenaFrame(mm->p[i + 1].x)) ||
        (IsShadowFrame(mm->p[i].y) || IsShadowFrame(mm->p[i + 1].x)) ||
        (!IsStaticStackFrame(mm->p[i].y) && IsStaticStackFrame(mm->p[i + 1].x)));
  }
  
  void PrintMemoryIntervals(int fd, const struct MemoryIntervals *mm) {
    char *p, mode[8];
    long i, w, frames, maptally = 0, gaptally = 0;
    for (w = i = 0; i < mm->i; ++i) {
      w = MAX(w, LengthInt64Thousands(mm->p[i].y + 1 - mm->p[i].x));
    }
    for (i = 0; i < mm->i; ++i) {
      frames = mm->p[i].y + 1 - mm->p[i].x;
      maptally += frames;
      __printf("%012x-%012x %s %,*dx%s", ADDR(mm->p[i].x), ADDR(mm->p[i].y + 1),
               DescribeMapping(mm->p[i].prot, mm->p[i].flags, mode), w, frames,
               DescribeFrame(mm->p[i].x));
      if (i + 1 < _mmi.i) {
        frames = mm->p[i + 1].x - mm->p[i].y - 1;
        if (frames && IsNoteworthyHole(i, mm)) {
          gaptally += frames;
          __printf(" w/ %,d frame hole", frames);
        }
      }
      if (mm->p[i].h != -1) {
        __printf(" h=%d", mm->p[i].h);
      }
      __printf("\r\n");
    }
    __printf("# %d frames mapped w/ %,d frames gapped\r\n", maptally, gaptally);
  }
  