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Diffstat (limited to 'third_party/glog/src/stacktrace_powerpc-inl.h')
| -rw-r--r-- | third_party/glog/src/stacktrace_powerpc-inl.h | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/third_party/glog/src/stacktrace_powerpc-inl.h b/third_party/glog/src/stacktrace_powerpc-inl.h new file mode 100644 index 0000000000..03b91089aa --- /dev/null +++ b/third_party/glog/src/stacktrace_powerpc-inl.h @@ -0,0 +1,130 @@ +// Copyright (c) 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. +// +// Author: Craig Silverstein +// +// Produce stack trace. I'm guessing (hoping!) the code is much like +// for x86. For apple machines, at least, it seems to be; see +// http://developer.apple.com/documentation/mac/runtimehtml/RTArch-59.html +// http://www.linux-foundation.org/spec/ELF/ppc64/PPC-elf64abi-1.9.html#STACK +// Linux has similar code: http://patchwork.ozlabs.org/linuxppc/patch?id=8882 + +#include <stdio.h> +#include <stdint.h> // for uintptr_t +#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; + return new_sp; +} + +// This ensures that GetStackTrace stes up the Link Register properly. +void StacktracePowerPCDummyFunction() __attribute__((noinline)); +void StacktracePowerPCDummyFunction() { __asm__ volatile(""); } + +// If you change this function, also change GetStackFrames below. +int GetStackTrace(void** result, int max_depth, int skip_count) { + void **sp; + // Apple OS X uses an old version of gnu as -- both Darwin 7.9.0 (Panther) + // and Darwin 8.8.1 (Tiger) use as 1.38. This means we have to use a + // different asm syntax. I don't know quite the best way to discriminate + // systems using the old as from the new one; I've gone with __APPLE__. +#ifdef __APPLE__ + __asm__ volatile ("mr %0,r1" : "=r" (sp)); +#else + __asm__ volatile ("mr %0,1" : "=r" (sp)); +#endif + + // On PowerPC, the "Link Register" or "Link Record" (LR), is a stack + // entry that holds the return address of the subroutine call (what + // instruction we run after our function finishes). This is the + // same as the stack-pointer of our parent routine, which is what we + // want here. While the compiler will always(?) set up LR for + // subroutine calls, it may not for leaf functions (such as this one). + // This routine forces the compiler (at least gcc) to push it anyway. + StacktracePowerPCDummyFunction(); + + // The LR save area is used by the callee, so the top entry is bogus. + skip_count++; + + int n = 0; + while (sp && n < max_depth) { + if (skip_count > 0) { + skip_count--; + } else { + // PowerPC has 3 main ABIs, which say where in the stack the + // Link Register is. For DARWIN and AIX (used by apple and + // linux ppc64), it's in sp[2]. For SYSV (used by linux ppc), + // it's in sp[1]. +#if defined(_CALL_AIX) || defined(_CALL_DARWIN) + result[n++] = *(sp+2); +#elif defined(_CALL_SYSV) + result[n++] = *(sp+1); +#elif defined(__APPLE__) || ((defined(__linux) || defined(__linux__)) && defined(__PPC64__)) + // This check is in case the compiler doesn't define _CALL_AIX/etc. + result[n++] = *(sp+2); +#elif defined(__linux) + // This check is in case the compiler doesn't define _CALL_SYSV. + result[n++] = *(sp+1); +#else +#error Need to specify the PPC ABI for your archiecture. +#endif + } + // Use strict unwinding rules. + sp = NextStackFrame<true>(sp); + } + return n; +} + +_END_GOOGLE_NAMESPACE_ |