chore(3p/abseil_cpp): unvendor abseil_cpp r/3786

we weren't actually using these sources anymore, okay?

Change-Id: If701571d9716de308d3512e1eb22c35db0877a66
Reviewed-on: https://cl.tvl.fyi/c/depot/+/5248
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Autosubmit: tazjin <tazjin@tvl.su>

1 files changed, 0 insertions, 199 deletions

diff --git a/third_party/abseil_cpp/absl/debugging/internal/stacktrace_aarch64-inl.inc b/third_party/abseil_cpp/absl/debugging/internal/stacktrace_aarch64-inl.inc
deleted file mode 100644
index f4859d7c210a..000000000000
--- a/third_party/abseil_cpp/absl/debugging/internal/stacktrace_aarch64-inl.inc
+++ /dev/null
@@ -1,199 +0,0 @@
-#ifndef ABSL_DEBUGGING_INTERNAL_STACKTRACE_AARCH64_INL_H_
-#define ABSL_DEBUGGING_INTERNAL_STACKTRACE_AARCH64_INL_H_
-
-// Generate stack tracer for aarch64
-
-#if defined(__linux__)
-#include <sys/mman.h>
-#include <ucontext.h>
-#include <unistd.h>
-#endif
-
-#include <atomic>
-#include <cassert>
-#include <cstdint>
-#include <iostream>
-
-#include "absl/base/attributes.h"
-#include "absl/debugging/internal/address_is_readable.h"
-#include "absl/debugging/internal/vdso_support.h"  // a no-op on non-elf or non-glibc systems
-#include "absl/debugging/stacktrace.h"
-
-static const uintptr_t kUnknownFrameSize = 0;
-
-#if defined(__linux__)
-// Returns the address of the VDSO __kernel_rt_sigreturn function, if present.
-static const unsigned char* GetKernelRtSigreturnAddress() {
-  constexpr uintptr_t kImpossibleAddress = 1;
-  ABSL_CONST_INIT static std::atomic<uintptr_t> memoized{kImpossibleAddress};
-  uintptr_t address = memoized.load(std::memory_order_relaxed);
-  if (address != kImpossibleAddress) {
-    return reinterpret_cast<const unsigned char*>(address);
-  }
-
-  address = reinterpret_cast<uintptr_t>(nullptr);
-
-#ifdef ABSL_HAVE_VDSO_SUPPORT
-  absl::debugging_internal::VDSOSupport vdso;
-  if (vdso.IsPresent()) {
-    absl::debugging_internal::VDSOSupport::SymbolInfo symbol_info;
-    auto lookup = [&](int type) {
-      return vdso.LookupSymbol("__kernel_rt_sigreturn", "LINUX_2.6.39", type,
-                               &symbol_info);
-    };
-    if ((!lookup(STT_FUNC) && !lookup(STT_NOTYPE)) ||
-        symbol_info.address == nullptr) {
-      // Unexpected: VDSO is present, yet the expected symbol is missing
-      // or null.
-      assert(false && "VDSO is present, but doesn't have expected symbol");
-    } else {
-      if (reinterpret_cast<uintptr_t>(symbol_info.address) !=
-          kImpossibleAddress) {
-        address = reinterpret_cast<uintptr_t>(symbol_info.address);
-      } else {
-        assert(false && "VDSO returned invalid address");
-      }
-    }
-  }
-#endif
-
-  memoized.store(address, std::memory_order_relaxed);
-  return reinterpret_cast<const unsigned char*>(address);
-}
-#endif  // __linux__
-
-// Compute the size of a stack frame in [low..high).  We assume that
-// low < high.  Return size of kUnknownFrameSize.
-template<typename T>
-static inline uintptr_t ComputeStackFrameSize(const T* low,
-                                              const T* high) {
-  const char* low_char_ptr = reinterpret_cast<const char *>(low);
-  const char* high_char_ptr = reinterpret_cast<const char *>(high);
-  return low < high ? high_char_ptr - low_char_ptr : kUnknownFrameSize;
-}
-
-// 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, bool WITH_CONTEXT>
-ABSL_ATTRIBUTE_NO_SANITIZE_ADDRESS  // May read random elements from stack.
-ABSL_ATTRIBUTE_NO_SANITIZE_MEMORY   // May read random elements from stack.
-static void **NextStackFrame(void **old_frame_pointer, const void *uc) {
-  void **new_frame_pointer = reinterpret_cast<void**>(*old_frame_pointer);
-  bool check_frame_size = true;
-
-#if defined(__linux__)
-  if (WITH_CONTEXT && uc != nullptr) {
-    // Check to see if next frame's return address is __kernel_rt_sigreturn.
-    if (old_frame_pointer[1] == GetKernelRtSigreturnAddress()) {
-      const ucontext_t *ucv = static_cast<const ucontext_t *>(uc);
-      // old_frame_pointer[0] is not suitable for unwinding, look at
-      // ucontext to discover frame pointer before signal.
-      void **const pre_signal_frame_pointer =
-          reinterpret_cast<void **>(ucv->uc_mcontext.regs[29]);
-
-      // Check that alleged frame pointer is actually readable. This is to
-      // prevent "double fault" in case we hit the first fault due to e.g.
-      // stack corruption.
-      if (!absl::debugging_internal::AddressIsReadable(
-              pre_signal_frame_pointer))
-        return nullptr;
-
-      // Alleged frame pointer is readable, use it for further unwinding.
-      new_frame_pointer = pre_signal_frame_pointer;
-
-      // Skip frame size check if we return from a signal. We may be using a
-      // an alternate stack for signals.
-      check_frame_size = false;
-    }
-  }
-#endif
-
-  // aarch64 ABI requires stack pointer to be 16-byte-aligned.
-  if ((reinterpret_cast<uintptr_t>(new_frame_pointer) & 15) != 0)
-    return nullptr;
-
-  // Check frame size.  In strict mode, we assume frames to be under
-  // 100,000 bytes.  In non-strict mode, we relax the limit to 1MB.
-  if (check_frame_size) {
-    const uintptr_t max_size = STRICT_UNWINDING ? 100000 : 1000000;
-    const uintptr_t frame_size =
-        ComputeStackFrameSize(old_frame_pointer, new_frame_pointer);
-    if (frame_size == kUnknownFrameSize || frame_size > max_size)
-      return nullptr;
-  }
-
-  return new_frame_pointer;
-}
-
-template <bool IS_STACK_FRAMES, bool IS_WITH_CONTEXT>
-ABSL_ATTRIBUTE_NO_SANITIZE_ADDRESS  // May read random elements from stack.
-ABSL_ATTRIBUTE_NO_SANITIZE_MEMORY   // May read random elements from stack.
-static int UnwindImpl(void** result, int* sizes, int max_depth, int skip_count,
-                      const void *ucp, int *min_dropped_frames) {
-#ifdef __GNUC__
-  void **frame_pointer = reinterpret_cast<void**>(__builtin_frame_address(0));
-#else
-# error reading stack point not yet supported on this platform.
-#endif
-
-  skip_count++;    // Skip the frame for this function.
-  int n = 0;
-
-  // The frame pointer points to low address of a frame.  The first 64-bit
-  // word of a frame points to the next frame up the call chain, which normally
-  // is just after the high address of the current frame.  The second word of
-  // a frame contains return adress of to the caller.   To find a pc value
-  // associated with the current frame, we need to go down a level in the call
-  // chain.  So we remember return the address of the last frame seen.  This
-  // does not work for the first stack frame, which belongs to UnwindImp() but
-  // we skip the frame for UnwindImp() anyway.
-  void* prev_return_address = nullptr;
-
-  while (frame_pointer && n < max_depth) {
-    // The absl::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_frame_pointer =
-        NextStackFrame<!IS_STACK_FRAMES, IS_WITH_CONTEXT>(frame_pointer, ucp);
-
-    if (skip_count > 0) {
-      skip_count--;
-    } else {
-      result[n] = prev_return_address;
-      if (IS_STACK_FRAMES) {
-        sizes[n] = ComputeStackFrameSize(frame_pointer, next_frame_pointer);
-      }
-      n++;
-    }
-    prev_return_address = frame_pointer[1];
-    frame_pointer = next_frame_pointer;
-  }
-  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 (; frame_pointer != nullptr && j < kMaxUnwind; j++) {
-      frame_pointer =
-          NextStackFrame<!IS_STACK_FRAMES, IS_WITH_CONTEXT>(frame_pointer, ucp);
-    }
-    *min_dropped_frames = j;
-  }
-  return n;
-}
-
-namespace absl {
-ABSL_NAMESPACE_BEGIN
-namespace debugging_internal {
-bool StackTraceWorksForTest() {
-  return true;
-}
-}  // namespace debugging_internal
-ABSL_NAMESPACE_END
-}  // namespace absl
-
-#endif  // ABSL_DEBUGGING_INTERNAL_STACKTRACE_AARCH64_INL_H_