Revert 126020 - Experiment for updating the tcmalloc chromium branch to r144 (gperftools 2.0).

third_party/tcmalloc/chromium/src/stacktrace_arm-inl.h

-// Copyright (c) 2011, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-// ---
-// Author: Doug Kwan
-// This is inspired by Craig Silverstein's PowerPC stacktrace code.
-//
-
-#ifndef BASE_STACKTRACE_ARM_INL_H_
-#define BASE_STACKTRACE_ARM_INL_H_
-// Note: this file is included into stacktrace.cc more than once.
-// Anything that should only be defined once should be here:
-
-#include <stdint.h>   // for uintptr_t
-#include "base/basictypes.h"  // for NULL
-#include <gperftools/stacktrace.h>
-
-// WARNING:
-// This only works if all your code is in either ARM or THUMB mode.  With
-// interworking, the frame pointer of the caller can either be in r11 (ARM
-// mode) or r7 (THUMB mode).  A callee only saves the frame pointer of its
-// mode in a fixed location on its stack frame.  If the caller is a different
-// mode, there is no easy way to find the frame pointer.  It can either be
-// still in the designated register or saved on stack along with other callee
-// saved registers.
-
-// Given a pointer to a stack frame, locate and return the calling
-// stackframe, or return NULL if no stackframe can be found. Perform sanity
-// checks (the strictness of which is controlled by the boolean parameter
-// "STRICT_UNWINDING") to reduce the chance that a bad pointer is returned.
-template<bool STRICT_UNWINDING>
-static void **NextStackFrame(void **old_sp) {
-  void **new_sp = (void**) old_sp[-1];
-
-  // Check that the transition from frame pointer old_sp to frame
-  // pointer new_sp isn't clearly bogus
-  if (STRICT_UNWINDING) {
-    // With the stack growing downwards, older stack frame must be
-    // at a greater address that the current one.
-    if (new_sp <= old_sp) return NULL;
-    // Assume stack frames larger than 100,000 bytes are bogus.
-    if ((uintptr_t)new_sp - (uintptr_t)old_sp > 100000) return NULL;
-  } else {
-    // In the non-strict mode, allow discontiguous stack frames.
-    // (alternate-signal-stacks for example).
-    if (new_sp == old_sp) return NULL;
-    // And allow frames upto about 1MB.
-    if ((new_sp > old_sp)
-        && ((uintptr_t)new_sp - (uintptr_t)old_sp > 1000000)) return NULL;
-  }
-  if ((uintptr_t)new_sp & (sizeof(void *) - 1)) return NULL;
-  return new_sp;
-}
-
-// This ensures that GetStackTrace stes up the Link Register properly.
-#ifdef __GNUC__
-void StacktraceArmDummyFunction() __attribute__((noinline));
-void StacktraceArmDummyFunction() { __asm__ volatile(""); }
-#else
-# error StacktraceArmDummyFunction() needs to be ported to this platform.
-#endif
-#endif  // BASE_STACKTRACE_ARM_INL_H_
-
-// Note: this part of the file is included several times.
-// Do not put globals below.
-
-// The following 4 functions are generated from the code below:
-//   GetStack{Trace,Frames}()
-//   GetStack{Trace,Frames}WithContext()
-//
-// These functions take the following args:
-//   void** result: the stack-trace, as an array
-//   int* sizes: the size of each stack frame, as an array
-//               (GetStackFrames* only)
-//   int max_depth: the size of the result (and sizes) array(s)
-//   int skip_count: how many stack pointers to skip before storing in result
-//   void* ucp: a ucontext_t* (GetStack{Trace,Frames}WithContext only)
-int GET_STACK_TRACE_OR_FRAMES {
-#ifdef __GNUC__
-  void **sp = reinterpret_cast<void**>(__builtin_frame_address(0));
-#else
-# error reading stack point not yet supported on this platform.
-#endif
-
-  // On ARM, the return address is stored in the link register (r14).
-  // This is not saved on the stack frame of a leaf function.  To
-  // simplify code that reads return addresses, we call a dummy
-  // function so that the return address of this function is also
-  // stored in the stack frame.  This works at least for gcc.
-  StacktraceArmDummyFunction();
-
-  int n = 0;
-  while (sp && n < max_depth) {
-    // The GetStackFrames routine is called when we are in some
-    // informational context (the failure signal handler for example).
-    // Use the non-strict unwinding rules to produce a stack trace
-    // that is as complete as possible (even if it contains a few bogus
-    // entries in some rare cases).
-    void **next_sp = NextStackFrame<IS_STACK_FRAMES == 0>(sp);
-
-    if (skip_count > 0) {
-      skip_count--;
-    } else {
-      result[n] = *sp;
-
-#if IS_STACK_FRAMES
-      if (next_sp > sp) {
-        sizes[n] = (uintptr_t)next_sp - (uintptr_t)sp;
-      } else {
-        // A frame-size of 0 is used to indicate unknown frame size.
-        sizes[n] = 0;
-      }
-#endif
-      n++;
-    }
-    sp = next_sp;
-  }
-  return n;
-}