--- Libc/Libc-583/gen/thread_stack_pcs.c
+++ Libc/Libc-1272.200.26/gen/thread_stack_pcs.c
@@ -1,15 +1,15 @@
 /*
- * Copyright (c) 1999, 2007 Apple Inc. All rights reserved.
+ * Copyright (c) 1999-2018 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,
@@ -17,7 +17,7 @@
  * 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@
  */
 
@@ -27,84 +27,73 @@
 #include <mach/mach.h>
 #include <mach/vm_statistics.h>
 #include <stdlib.h>
+#include "stack_logging.h"
 
-#if defined(__i386__) || defined(__x86_64__) || defined(__arm__)
+
+#if defined(__i386__) || defined(__x86_64__) || defined(__arm__) || defined(__arm64__)
 #define FP_LINK_OFFSET 1
-#elif defined(__ppc__) || defined(__ppc64__)
-#define FP_LINK_OFFSET 2
 #else
-#error  ********** Unimplemented architecture
+#error ********** Unimplemented architecture
 #endif
 
+
 #define	INSTACK(a)	((a) >= stackbot && (a) <= stacktop)
-#if defined(__ppc__) || defined(__ppc64__) || defined(__x86_64__)
+#if defined(__x86_64__)
 #define	ISALIGNED(a)	((((uintptr_t)(a)) & 0xf) == 0)
-#elif defined(__arm__)
-#define	ISALIGNED(a)	((((uintptr_t)(a)) & 0x1) == 0)
 #elif defined(__i386__)
 #define	ISALIGNED(a)	((((uintptr_t)(a)) & 0xf) == 8)
+#elif defined(__arm__) || defined(__arm64__)
+#define	ISALIGNED(a)	((((uintptr_t)(a)) & 0x1) == 0)
 #endif
 
 __private_extern__  __attribute__((noinline))
 void
-_thread_stack_pcs(vm_address_t *buffer, unsigned max, unsigned *nb, unsigned skip)
+_thread_stack_pcs(vm_address_t *buffer, unsigned max, unsigned *nb,
+		unsigned skip, void *startfp)
 {
-    void *frame, *next;
-    pthread_t self = pthread_self();
-    void *stacktop = pthread_get_stackaddr_np(self);
-    void *stackbot = stacktop - pthread_get_stacksize_np(self);
+	void *frame, *next;
+	pthread_t self = pthread_self();
+	void *stacktop = pthread_get_stackaddr_np(self);
+	void *stackbot = stacktop - pthread_get_stacksize_np(self);
 
-    *nb = 0;
+	*nb = 0;
 
-    /* make sure return address is never out of bounds */
-    stacktop -= (FP_LINK_OFFSET + 1) * sizeof(void *);
+	/* make sure return address is never out of bounds */
+	stacktop -= (FP_LINK_OFFSET + 1) * sizeof(void *);
 
-    /*
-     * The original implementation called the first_frame_address() function,
-     * which returned the stack frame pointer.  The problem was that in ppc,
-     * it was a leaf function, so no new stack frame was set up with
-     * optimization turned on (while a new stack frame was set up without
-     * optimization).  We now inline the code to get the stack frame pointer,
-     * so we are consistent about the stack frame.
-     */
-#if defined(__i386__) || defined(__x86_64__) || defined(__arm__)
-    frame = __builtin_frame_address(0);
-#elif defined(__ppc__) || defined(__ppc64__)
-    /* __builtin_frame_address IS BROKEN IN BEAKER: RADAR #2340421 */
-    __asm__ volatile("mr %0, r1" : "=r" (frame));
-#endif
-    if(!INSTACK(frame) || !ISALIGNED(frame))
-	return;
-#if defined(__ppc__) || defined(__ppc64__)
-    /* back up the stack pointer up over the current stack frame */
-    next = *(void **)frame;
-    if(!INSTACK(next) || !ISALIGNED(next) || next <= frame)
-	return;
-    frame = next;
-#endif
-    while (skip--) {
-	next = *(void **)frame;
-	if(!INSTACK(next) || !ISALIGNED(next) || next <= frame)
-	    return;
-	frame = next;
-    }
-    while (max--) {
-        buffer[*nb] = *(vm_address_t *)(((void **)frame) + FP_LINK_OFFSET);
-        (*nb)++;
-	next = *(void **)frame;
-	if(!INSTACK(next) || !ISALIGNED(next) || next <= frame)
-	    return;
-	frame = next;
-    }
+	frame = __builtin_frame_address(0);
+	if(!INSTACK(frame) || !ISALIGNED(frame))
+		return;
+	while ((startfp && startfp >= *(void **)frame) || skip--) {
+		next = *(void **)frame;
+		if(!INSTACK(next) || !ISALIGNED(next) || next <= frame)
+			return;
+		frame = next;
+	}
+	while (max--) {
+		void *retaddr = (void *)*(vm_address_t *)
+				(((void **)frame) + FP_LINK_OFFSET);
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wint-conversion"
+		buffer[*nb] = retaddr;
+#pragma clang diagnostic pop
+		(*nb)++;
+		next = *(void **)frame;
+		if(!INSTACK(next) || !ISALIGNED(next) || next <= frame)
+			return;
+		frame = next;
+	}
 }
 
+// Prevent thread_stack_pcs() from getting tail-call-optimized into
+// _thread_stack_pcs() on 64-bit environments, thus making the "number of hot
+// frames to skip" be more predictable, giving more consistent backtraces.
+//
+// See <rdar://problem/5364825> "stack logging: frames keep getting truncated"
+// for why this is necessary.
+__attribute__((disable_tail_calls))
 void
 thread_stack_pcs(vm_address_t *buffer, unsigned max, unsigned *nb)
 {
-    _thread_stack_pcs(buffer, max, nb, 0);
-
-    // The following prevents thread_stack_pcs() from getting tail-call-optimized into _thread_stack_pcs() on 64-bit environments,
-    // thus making the "number of hot frames to skip" be more predictable, giving more consistent backtraces.
-    // See <rdar://problem/5364825> "stack logging: frames keep getting truncated" for why this is necessary.
-    __asm__ volatile("");
+	_thread_stack_pcs(buffer, max, nb, 0, NULL);
 }