Squash: Fix bugs

trunk/3rdparty/gperftools-2-fit/src/stacktrace_arm-inl.h

@@ -0,0 +1,148 @@
+// -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*-
+// 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)
+static 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();
+
+  skip_count++; // skip parent frame due to indirection in stacktrace.cc
+
+  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;
+}