merge(3p/glog): Vendor glog from commit 'afe04691'

third_party/glog/src/stacktrace_x86-inl.h

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+// Copyright (c) 2000 - 2007, 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.
+//
+// Produce stack trace
+
+#include <stdint.h>   // for uintptr_t
+
+#include "utilities.h"   // for OS_* macros
+
+#if !defined(OS_WINDOWS)
+#include <unistd.h>
+#include <sys/mman.h>
+#endif
+
+#include <stdio.h>  // for NULL
+#include "stacktrace.h"
+
+_START_GOOGLE_NAMESPACE_
+
+// 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;
+
+  // 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;
+#ifdef __i386__
+  // On 64-bit machines, the stack pointer can be very close to
+  // 0xffffffff, so we explicitly check for a pointer into the
+  // last two pages in the address space
+  if ((uintptr_t)new_sp >= 0xffffe000) return NULL;
+#endif
+#if !defined(OS_WINDOWS)
+  if (!STRICT_UNWINDING) {
+    // Lax sanity checks cause a crash in 32-bit tcmalloc/crash_reason_test
+    // on AMD-based machines with VDSO-enabled kernels.
+    // Make an extra sanity check to insure new_sp is readable.
+    // Note: NextStackFrame<false>() is only called while the program
+    //       is already on its last leg, so it's ok to be slow here.
+    static int page_size = getpagesize();
+    void *new_sp_aligned = (void *)((uintptr_t)new_sp & ~(page_size - 1));
+    if (msync(new_sp_aligned, page_size, MS_ASYNC) == -1)
+      return NULL;
+  }
+#endif
+  return new_sp;
+}
+
+// If you change this function, also change GetStackFrames below.
+int GetStackTrace(void** result, int max_depth, int skip_count) {
+  void **sp;
+
+#ifdef __GNUC__
+#if __GNUC__ * 100 + __GNUC_MINOR__ >= 402
+#define USE_BUILTIN_FRAME_ADDRESS
+#endif
+#endif
+
+#ifdef USE_BUILTIN_FRAME_ADDRESS
+  sp = reinterpret_cast<void**>(__builtin_frame_address(0));
+#elif defined(__i386__)
+  // Stack frame format:
+  //    sp[0]   pointer to previous frame
+  //    sp[1]   caller address
+  //    sp[2]   first argument
+  //    ...
+  sp = (void **)&result - 2;
+#elif defined(__x86_64__)
+  // __builtin_frame_address(0) can return the wrong address on gcc-4.1.0-k8
+  unsigned long rbp;
+  // Move the value of the register %rbp into the local variable rbp.
+  // We need 'volatile' to prevent this instruction from getting moved
+  // around during optimization to before function prologue is done.
+  // An alternative way to achieve this
+  // would be (before this __asm__ instruction) to call Noop() defined as
+  //   static void Noop() __attribute__ ((noinline));  // prevent inlining
+  //   static void Noop() { asm(""); }  // prevent optimizing-away
+  __asm__ volatile ("mov %%rbp, %0" : "=r" (rbp));
+  // Arguments are passed in registers on x86-64, so we can't just
+  // offset from &result
+  sp = (void **) rbp;
+#endif
+
+  int n = 0;
+  while (sp && n < max_depth) {
+    if (*(sp+1) == (void *)0) {
+      // In 64-bit code, we often see a frame that
+      // points to itself and has a return address of 0.
+      break;
+    }
+    if (skip_count > 0) {
+      skip_count--;
+    } else {
+      result[n++] = *(sp+1);
+    }
+    // Use strict unwinding rules.
+    sp = NextStackFrame<true>(sp);
+  }
+  return n;
+}
+
+_END_GOOGLE_NAMESPACE_