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, 158 deletions

diff --git a/third_party/abseil_cpp/absl/debugging/internal/vdso_support.h b/third_party/abseil_cpp/absl/debugging/internal/vdso_support.h
deleted file mode 100644
index 6562c6c2350a..000000000000
--- a/third_party/abseil_cpp/absl/debugging/internal/vdso_support.h
+++ /dev/null
@@ -1,158 +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
-//
-//      https://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.
-//
-
-// Allow dynamic symbol lookup in the kernel VDSO page.
-//
-// VDSO stands for "Virtual Dynamic Shared Object" -- a page of
-// executable code, which looks like a shared library, but doesn't
-// necessarily exist anywhere on disk, and which gets mmap()ed into
-// every process by kernels which support VDSO, such as 2.6.x for 32-bit
-// executables, and 2.6.24 and above for 64-bit executables.
-//
-// More details could be found here:
-// http://www.trilithium.com/johan/2005/08/linux-gate/
-//
-// VDSOSupport -- a class representing kernel VDSO (if present).
-//
-// Example usage:
-//  VDSOSupport vdso;
-//  VDSOSupport::SymbolInfo info;
-//  typedef (*FN)(unsigned *, void *, void *);
-//  FN fn = nullptr;
-//  if (vdso.LookupSymbol("__vdso_getcpu", "LINUX_2.6", STT_FUNC, &info)) {
-//     fn = reinterpret_cast<FN>(info.address);
-//  }
-
-#ifndef ABSL_DEBUGGING_INTERNAL_VDSO_SUPPORT_H_
-#define ABSL_DEBUGGING_INTERNAL_VDSO_SUPPORT_H_
-
-#include <atomic>
-
-#include "absl/base/attributes.h"
-#include "absl/debugging/internal/elf_mem_image.h"
-
-#ifdef ABSL_HAVE_ELF_MEM_IMAGE
-
-#ifdef ABSL_HAVE_VDSO_SUPPORT
-#error ABSL_HAVE_VDSO_SUPPORT cannot be directly set
-#else
-#define ABSL_HAVE_VDSO_SUPPORT 1
-#endif
-
-namespace absl {
-ABSL_NAMESPACE_BEGIN
-namespace debugging_internal {
-
-// NOTE: this class may be used from within tcmalloc, and can not
-// use any memory allocation routines.
-class VDSOSupport {
- public:
-  VDSOSupport();
-
-  typedef ElfMemImage::SymbolInfo SymbolInfo;
-  typedef ElfMemImage::SymbolIterator SymbolIterator;
-
-  // On PowerPC64 VDSO symbols can either be of type STT_FUNC or STT_NOTYPE
-  // depending on how the kernel is built.  The kernel is normally built with
-  // STT_NOTYPE type VDSO symbols.  Let's make things simpler first by using a
-  // compile-time constant.
-#ifdef __powerpc64__
-  enum { kVDSOSymbolType = STT_NOTYPE };
-#else
-  enum { kVDSOSymbolType = STT_FUNC };
-#endif
-
-  // Answers whether we have a vdso at all.
-  bool IsPresent() const { return image_.IsPresent(); }
-
-  // Allow to iterate over all VDSO symbols.
-  SymbolIterator begin() const { return image_.begin(); }
-  SymbolIterator end() const { return image_.end(); }
-
-  // Look up versioned dynamic symbol in the kernel VDSO.
-  // Returns false if VDSO is not present, or doesn't contain given
-  // symbol/version/type combination.
-  // If info_out != nullptr, additional details are filled in.
-  bool LookupSymbol(const char *name, const char *version,
-                    int symbol_type, SymbolInfo *info_out) const;
-
-  // Find info about symbol (if any) which overlaps given address.
-  // Returns true if symbol was found; false if VDSO isn't present
-  // or doesn't have a symbol overlapping given address.
-  // If info_out != nullptr, additional details are filled in.
-  bool LookupSymbolByAddress(const void *address, SymbolInfo *info_out) const;
-
-  // Used only for testing. Replace real VDSO base with a mock.
-  // Returns previous value of vdso_base_. After you are done testing,
-  // you are expected to call SetBase() with previous value, in order to
-  // reset state to the way it was.
-  const void *SetBase(const void *s);
-
-  // Computes vdso_base_ and returns it. Should be called as early as
-  // possible; before any thread creation, chroot or setuid.
-  static const void *Init();
-
- private:
-  // image_ represents VDSO ELF image in memory.
-  // image_.ehdr_ == nullptr implies there is no VDSO.
-  ElfMemImage image_;
-
-  // Cached value of auxv AT_SYSINFO_EHDR, computed once.
-  // This is a tri-state:
-  //   kInvalidBase   => value hasn't been determined yet.
-  //              0   => there is no VDSO.
-  //           else   => vma of VDSO Elf{32,64}_Ehdr.
-  //
-  // When testing with mock VDSO, low bit is set.
-  // The low bit is always available because vdso_base_ is
-  // page-aligned.
-  static std::atomic<const void *> vdso_base_;
-
-  // NOLINT on 'long' because these routines mimic kernel api.
-  // The 'cache' parameter may be used by some versions of the kernel,
-  // and should be nullptr or point to a static buffer containing at
-  // least two 'long's.
-  static long InitAndGetCPU(unsigned *cpu, void *cache,     // NOLINT 'long'.
-                            void *unused);
-  static long GetCPUViaSyscall(unsigned *cpu, void *cache,  // NOLINT 'long'.
-                               void *unused);
-  typedef long (*GetCpuFn)(unsigned *cpu, void *cache,      // NOLINT 'long'.
-                           void *unused);
-
-  // This function pointer may point to InitAndGetCPU,
-  // GetCPUViaSyscall, or __vdso_getcpu at different stages of initialization.
-  ABSL_CONST_INIT static std::atomic<GetCpuFn> getcpu_fn_;
-
-  friend int GetCPU(void);  // Needs access to getcpu_fn_.
-
-  VDSOSupport(const VDSOSupport&) = delete;
-  VDSOSupport& operator=(const VDSOSupport&) = delete;
-};
-
-// Same as sched_getcpu() on later glibc versions.
-// Return current CPU, using (fast) __vdso_getcpu@LINUX_2.6 if present,
-// otherwise use syscall(SYS_getcpu,...).
-// May return -1 with errno == ENOSYS if the kernel doesn't
-// support SYS_getcpu.
-int GetCPU();
-
-}  // namespace debugging_internal
-ABSL_NAMESPACE_END
-}  // namespace absl
-
-#endif  // ABSL_HAVE_ELF_MEM_IMAGE
-
-#endif  // ABSL_DEBUGGING_INTERNAL_VDSO_SUPPORT_H_