diff options
Diffstat (limited to 'absl/debugging/internal/stacktrace_libunwind-inl.inc')
-rw-r--r-- | absl/debugging/internal/stacktrace_libunwind-inl.inc | 128 |
1 files changed, 0 insertions, 128 deletions
diff --git a/absl/debugging/internal/stacktrace_libunwind-inl.inc b/absl/debugging/internal/stacktrace_libunwind-inl.inc deleted file mode 100644 index e9c2d26a5fe4..000000000000 --- a/absl/debugging/internal/stacktrace_libunwind-inl.inc +++ /dev/null @@ -1,128 +0,0 @@ -// Copyright 2017 The Abseil Authors. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// You may obtain a copy of the License at -// -// http://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS IS" BASIS, -// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -// See the License for the specific language governing permissions and -// limitations under the License. - -#ifndef ABSL_DEBUGGING_INTERNAL_STACKTRACE_LIBUNWIND_INL_H_ -#define ABSL_DEBUGGING_INTERNAL_STACKTRACE_LIBUNWIND_INL_H_ - -// We only need local unwinder. -#define UNW_LOCAL_ONLY - -extern "C" { -#include "third_party/libunwind/include/libunwind.h" -} -#include "absl/debugging/stacktrace.h" - -#include "absl/base/dynamic_annotations.h" -#include "absl/base/internal/raw_logging.h" - -// Sometimes, we can try to get a stack trace from within a stack -// trace, because we don't block signals inside libunwind (which would be too -// expensive: the two extra system calls per stack trace do matter here). -// That can cause a self-deadlock (as in http://b/5722312). -// Protect against such reentrant call by failing to get a stack trace. -// -// We use __thread here because the code here is extremely low level -- it is -// called while collecting stack traces from within malloc and mmap, and thus -// can not call anything which might call malloc or mmap itself. -// In particular, using PerThread or STATIC_THREAD_LOCAL_POD -// here will cause infinite recursion for at least dbg/piii builds with -// crosstool-v12. -static __thread int recursive; - -template <bool IS_STACK_FRAMES, bool IS_WITH_CONTEXT> -static int UnwindImpl(void** result, int* sizes, int max_depth, int skip_count, - const void *, int *min_dropped_frames) { - if (recursive) { - return 0; - } - ++recursive; - - int n = 0; - if (IS_STACK_FRAMES) { - void *ip; - unw_cursor_t cursor; - unw_context_t uc; - unw_word_t sp = 0, next_sp = 0; - - unw_getcontext(&uc); - ABSL_RAW_CHECK(unw_init_local(&cursor, &uc) >= 0, "unw_init_local failed"); - skip_count++; // Do not include current frame - - while (skip_count--) { - if (unw_step(&cursor) <= 0) { - goto out; - } - if (unw_get_reg(&cursor, UNW_REG_SP, &next_sp)) { - goto out; - } - } - - while (n < max_depth) { - if (unw_get_reg(&cursor, UNW_REG_IP, (unw_word_t *) &ip) < 0) { - break; - } - sizes[n] = 0; - result[n++] = ip; - if (unw_step(&cursor) <= 0) { - break; - } - sp = next_sp; - if (unw_get_reg(&cursor, UNW_REG_SP, &next_sp) , 0) { - break; - } - sizes[n - 1] = next_sp - sp; - } - if (min_dropped_frames != nullptr) { - // Implementation detail: we clamp the max of frames we are willing to - // count, so as not to spend too much time in the loop below. - const int kMaxUnwind = 200; - int j = 0; - for (; j < kMaxUnwind; j++) { - if (unw_step(&cursor) < 0) { - break; - } - } - *min_dropped_frames = j; - } - } else { - skip_count++; // Do not include current frame. - void **result_all = reinterpret_cast<void**>( - alloca(sizeof(void*) * (max_depth + skip_count))); - int rc = unw_backtrace(result_all, max_depth + skip_count); - - if (rc > 0) { - // Tell MSan that result_all has been initialized. b/34965936. - ANNOTATE_MEMORY_IS_INITIALIZED(result_all, rc * sizeof(void*)); - } - - if (rc > skip_count) { - memcpy(result, &result_all[skip_count], - sizeof(void*) * (rc - skip_count)); - n = rc - skip_count; - } else { - n = 0; - } - - if (min_dropped_frames != nullptr) { - // Not implemented. - *min_dropped_frames = 0; - } - } - - out: - --recursive; - return n; -} - -#endif // ABSL_DEBUGGING_INTERNAL_STACKTRACE_LIBUNWIND_INL_H_ |