--- libmalloc/libmalloc-374.40.6/src/stack_trace.c
+++ /dev/null
@@ -1,159 +0,0 @@
-/*
- * Copyright (c) 2020 Apple Inc. All rights reserved.
- *
- * @APPLE_LICENSE_HEADER_START@
- *
- * This file contains Original Code and/or Modifications of Original Code
- * as defined in and that are subject to the Apple Public Source License
- * Version 2.0 (the 'License'). You may not use this file except in
- * compliance with the License. Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
- *
- * The Original Code and all software distributed under the License are
- * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
- * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
- * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
- * Please see the License for the specific language governing rights and
- * limitations under the License.
- *
- * @APPLE_LICENSE_HEADER_END@
- */
-
-#include "stack_trace.h"
-
-#include <TargetConditionals.h>
-#include <thread_stack_pcs.h>
-
-
-// Note: Shifts on signed types are a minefield.  Avoid doing it!
-
-static uintptr_t
-zigzag_encode(uintptr_t val)
-{
-	uintptr_t x = val << 1;
-	return ((intptr_t)val < 0) ? ~x : x;
-}
-
-static uintptr_t
-zigzag_decode(uintptr_t encoded_val)
-{
-	uintptr_t x = encoded_val >> 1;
-	return (encoded_val & 1) ? ~x : x;
-}
-
-static uintptr_t
-codeoffset_encode(intptr_t val)
-{
-	intptr_t x = val;
-	if (TARGET_CPU_ARM64) x /= 4;  // instructions are 4 byte-aligned
-	return zigzag_encode(x);
-}
-
-static intptr_t
-codeoffset_decode(uintptr_t encoded_val)
-{
-	intptr_t x = zigzag_decode(encoded_val);
-	if (TARGET_CPU_ARM64) x *= 4;  // instructions are 4 byte-aligned
-	return x;
-}
-
-const static uintptr_t k_shift = 7;
-const static uintptr_t k_stop_bit = 1 << k_shift;
-const static uintptr_t k_data_bits = ~k_stop_bit;
-
-static size_t
-varint_encode(uint8_t *buffer, size_t size, uintptr_t val)
-{
-	uintptr_t x = val;
-	size_t len = 0;
-	do {
-		if (len == size) {
-			return 0;
-		}
-		buffer[len] = x & k_data_bits;
-		x >>= k_shift;
-		len++;
-	} while (x);
-
-	buffer[len - 1] |= k_stop_bit;
-	return len;
-}
-
-static size_t
-varint_decode(const uint8_t *buffer, size_t size, uintptr_t *val)
-{
-	uintptr_t x = 0;
-	size_t len = 0;
-	do {
-		if (len == size) {
-			return 0;
-		}
-		uintptr_t bits = buffer[len] & k_data_bits;
-		x |= bits << (len * k_shift);
-		len++;
-	} while (!(buffer[len - 1] & k_stop_bit));
-
-	*val = x;
-	return len;
-}
-
-static size_t
-trace_encode(uint8_t *buffer, size_t size, const vm_address_t *addrs, uint32_t num_addrs)
-{
-	size_t used = 0;
-	for (uint32_t i = 0; i < num_addrs; i++) {
-		intptr_t offset = addrs[i] - (i > 0 ? addrs[i - 1] : 0);
-		uintptr_t encoded_offset = codeoffset_encode(offset);
-		size_t len = varint_encode(&buffer[used], size - used, encoded_offset);
-		if (len == 0) {
-			break;
-		}
-		used += len;
-	}
-
-	return used;
-}
-
-uint32_t
-trace_decode(const uint8_t *buffer, size_t size, vm_address_t *addrs, uint32_t num_addrs)
-{
-	size_t used = 0;
-	uint32_t i;
-	for (i = 0; i < num_addrs; i++) {
-		uintptr_t encoded_offset;
-		size_t len = varint_decode(&buffer[used], size - used, &encoded_offset);
-		if (len == 0) {
-			break;
-		}
-		used += len;
-
-		intptr_t offset = codeoffset_decode(encoded_offset);
-		addrs[i] = offset + (i > 0 ? addrs[i - 1] : 0);
-	}
-
-	return i;
-}
-
-MALLOC_NOINLINE
-size_t
-trace_collect(uint8_t *buffer, size_t size)
-{
-	// frame 0: thread_stack_pcs() itself
-	// frame 1: this function (no inline)
-	// last frame: usually garbage value
-	const uint32_t dropped_frames = 3;
-	const uint32_t good_frames = 64;
-	const uint32_t max_frames = good_frames + dropped_frames;
-	vm_address_t frames[max_frames];
-
-	uint32_t num_frames;
-	thread_stack_pcs(frames, max_frames, &num_frames);
-	if (num_frames <= dropped_frames) {
-		return 0;
-	}
-
-	uint32_t num_addrs = num_frames - dropped_frames;
-	return trace_encode(buffer, size, &frames[2], num_addrs);
-}