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Diffstat (limited to 'pypy/module/_vmprof/src/getpc.h')
| -rw-r--r-- | pypy/module/_vmprof/src/getpc.h | 187 |
1 files changed, 0 insertions, 187 deletions
diff --git a/pypy/module/_vmprof/src/getpc.h b/pypy/module/_vmprof/src/getpc.h deleted file mode 100644 index 999232f6a3..0000000000 --- a/pypy/module/_vmprof/src/getpc.h +++ /dev/null @@ -1,187 +0,0 @@ -// -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- -// Copyright (c) 2005, 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: Craig Silverstein -// -// This is an internal header file used by profiler.cc. It defines -// the single (inline) function GetPC. GetPC is used in a signal -// handler to figure out the instruction that was being executed when -// the signal-handler was triggered. -// -// To get this, we use the ucontext_t argument to the signal-handler -// callback, which holds the full context of what was going on when -// the signal triggered. How to get from a ucontext_t to a Program -// Counter is OS-dependent. - -#ifndef BASE_GETPC_H_ -#define BASE_GETPC_H_ - -#include "config.h" - -// On many linux systems, we may need _GNU_SOURCE to get access to -// the defined constants that define the register we want to see (eg -// REG_EIP). Note this #define must come first! -#define _GNU_SOURCE 1 -// If #define _GNU_SOURCE causes problems, this might work instead. -// It will cause problems for FreeBSD though!, because it turns off -// the needed __BSD_VISIBLE. -//#define _XOPEN_SOURCE 500 - -#include <string.h> // for memcmp -#if defined(HAVE_SYS_UCONTEXT_H) -#include <sys/ucontext.h> -#elif defined(HAVE_UCONTEXT_H) -#include <ucontext.h> // for ucontext_t (and also mcontext_t) -#elif defined(HAVE_CYGWIN_SIGNAL_H) -#include <cygwin/signal.h> -typedef ucontext ucontext_t; -#endif - - -// Take the example where function Foo() calls function Bar(). For -// many architectures, Bar() is responsible for setting up and tearing -// down its own stack frame. In that case, it's possible for the -// interrupt to happen when execution is in Bar(), but the stack frame -// is not properly set up (either before it's done being set up, or -// after it's been torn down but before Bar() returns). In those -// cases, the stack trace cannot see the caller function anymore. -// -// GetPC can try to identify this situation, on architectures where it -// might occur, and unwind the current function call in that case to -// avoid false edges in the profile graph (that is, edges that appear -// to show a call skipping over a function). To do this, we hard-code -// in the asm instructions we might see when setting up or tearing -// down a stack frame. -// -// This is difficult to get right: the instructions depend on the -// processor, the compiler ABI, and even the optimization level. This -// is a best effort patch -- if we fail to detect such a situation, or -// mess up the PC, nothing happens; the returned PC is not used for -// any further processing. -struct CallUnrollInfo { - // Offset from (e)ip register where this instruction sequence - // should be matched. Interpreted as bytes. Offset 0 is the next - // instruction to execute. Be extra careful with negative offsets in - // architectures of variable instruction length (like x86) - it is - // not that easy as taking an offset to step one instruction back! - int pc_offset; - // The actual instruction bytes. Feel free to make it larger if you - // need a longer sequence. - unsigned char ins[16]; - // How many bytes to match from ins array? - int ins_size; - // The offset from the stack pointer (e)sp where to look for the - // call return address. Interpreted as bytes. - int return_sp_offset; -}; - - -// The dereferences needed to get the PC from a struct ucontext were -// determined at configure time, and stored in the macro -// PC_FROM_UCONTEXT in config.h. The only thing we need to do here, -// then, is to do the magic call-unrolling for systems that support it. - -// -- Special case 1: linux x86, for which we have CallUnrollInfo -#if defined(__linux) && defined(__i386) && defined(__GNUC__) -static const CallUnrollInfo callunrollinfo[] = { - // Entry to a function: push %ebp; mov %esp,%ebp - // Top-of-stack contains the caller IP. - { 0, - {0x55, 0x89, 0xe5}, 3, - 0 - }, - // Entry to a function, second instruction: push %ebp; mov %esp,%ebp - // Top-of-stack contains the old frame, caller IP is +4. - { -1, - {0x55, 0x89, 0xe5}, 3, - 4 - }, - // Return from a function: RET. - // Top-of-stack contains the caller IP. - { 0, - {0xc3}, 1, - 0 - } -}; - -inline void* GetPC(ucontext_t *signal_ucontext) { - // See comment above struct CallUnrollInfo. Only try instruction - // flow matching if both eip and esp looks reasonable. - const int eip = signal_ucontext->uc_mcontext.gregs[REG_EIP]; - const int esp = signal_ucontext->uc_mcontext.gregs[REG_ESP]; - if ((eip & 0xffff0000) != 0 && (~eip & 0xffff0000) != 0 && - (esp & 0xffff0000) != 0) { - char* eip_char = reinterpret_cast<char*>(eip); - for (int i = 0; i < sizeof(callunrollinfo)/sizeof(*callunrollinfo); ++i) { - if (!memcmp(eip_char + callunrollinfo[i].pc_offset, - callunrollinfo[i].ins, callunrollinfo[i].ins_size)) { - // We have a match. - void **retaddr = (void**)(esp + callunrollinfo[i].return_sp_offset); - return *retaddr; - } - } - } - return (void*)eip; -} - -// Special case #2: Windows, which has to do something totally different. -#elif defined(_WIN32) || defined(__CYGWIN__) || defined(__CYGWIN32__) || defined(__MINGW32__) -// If this is ever implemented, probably the way to do it is to have -// profiler.cc use a high-precision timer via timeSetEvent: -// http://msdn2.microsoft.com/en-us/library/ms712713.aspx -// We'd use it in mode TIME_CALLBACK_FUNCTION/TIME_PERIODIC. -// The callback function would be something like prof_handler, but -// alas the arguments are different: no ucontext_t! I don't know -// how we'd get the PC (using StackWalk64?) -// http://msdn2.microsoft.com/en-us/library/ms680650.aspx - -#include "base/logging.h" // for RAW_LOG -#ifndef HAVE_CYGWIN_SIGNAL_H -typedef int ucontext_t; -#endif - -inline void* GetPC(ucontext_t *signal_ucontext) { - RAW_LOG(ERROR, "GetPC is not yet implemented on Windows\n"); - return NULL; -} - -// Normal cases. If this doesn't compile, it's probably because -// PC_FROM_UCONTEXT is the empty string. You need to figure out -// the right value for your system, and add it to the list in -// configure.ac (or set it manually in your config.h). -#else -inline void* GetPC(ucontext_t *signal_ucontext) { - return (void*)signal_ucontext->PC_FROM_UCONTEXT; // defined in config.h -} - -#endif - -#endif // BASE_GETPC_H_ |