Export of internal Abseil changes

--
20405fc394419d434d3ea09b2e62e4edcb282421 by Christian Blichmann <cblichmann@google.com>:

Include `status` subdirectory in main `CMakeLists.txt`

PiperOrigin-RevId: 297125966

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101087af9689612bdda679ee0869e5cde4472244 by Matt Kulukundis <kfm@google.com>:

Fix typo

PiperOrigin-RevId: 296991360

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55ff5bc6970d46214c0459d3a7a23973c7dc69b9 by Andy Getzendanner <durandal@google.com>:

Extract logging's ErrnoSaver to absl::base_internal and use it in a couple other places.

PiperOrigin-RevId: 296969168

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b7cd7550297d53766576f751436617200c65831b by Abseil Team <absl-team@google.com>:

Internal change

PiperOrigin-RevId: 296951474

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8c04c73fc53f9a09c3e2400812b931157f35fe07 by Andy Soffer <asoffer@google.com>:

Auto-generate list of files in the DLL, and add new build targets to the DLL.

PiperOrigin-RevId: 296932061

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2f77829e196094f1addefd8ac2ac9e398c5b6100 by Andy Soffer <asoffer@google.com>:

Fix bug introduced by DLL where we couldn't build shared libraries on
non-windows platforms.

Fixes #623

PiperOrigin-RevId: 296919347

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b768163dbbff0c561b9dff0218a699e5e4fd33f3 by Abseil Team <absl-team@google.com>:

typo: microprosessor

PiperOrigin-RevId: 296904933

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b185da0dac44c91855373f0723df9242cbfb3db3 by Matthew Brown <matthewbr@google.com>:

Internal cleanup

PiperOrigin-RevId: 296509711
GitOrigin-RevId: 20405fc394419d434d3ea09b2e62e4edcb282421
Change-Id: I55c8eba6f353ceb337455ae144ab743ea21edbef

absl/debugging/BUILD.bazel

@@ -134,6 +134,7 @@ cc_library(
         "//absl/base",
         "//absl/base:config",
         "//absl/base:core_headers",
+        "//absl/base:errno_saver",
         "//absl/base:raw_logging_internal",
     ],
 )
@@ -174,6 +175,7 @@ cc_library(
         "//absl/base:config",
         "//absl/base:core_headers",
         "//absl/base:dynamic_annotations",
+        "//absl/base:errno_saver",
         "//absl/base:raw_logging_internal",
     ],
 )

absl/debugging/CMakeLists.txt

@@ -118,6 +118,7 @@ absl_cc_library(
     absl::base
     absl::config
     absl::core_headers
+    absl::errno_saver
     absl::raw_logging_internal
   PUBLIC
 )
@@ -156,6 +157,7 @@ absl_cc_library(
     absl::core_headers
     absl::config
     absl::dynamic_annotations
+    absl::errno_saver
     absl::raw_logging_internal
 )
 

absl/debugging/failure_signal_handler.cc

@@ -41,6 +41,7 @@
 #include <ctime>
 
 #include "absl/base/attributes.h"
+#include "absl/base/internal/errno_saver.h"
 #include "absl/base/internal/raw_logging.h"
 #include "absl/base/internal/sysinfo.h"
 #include "absl/debugging/internal/examine_stack.h"
@@ -214,9 +215,8 @@ static void InstallOneFailureHandler(FailureSignalData* data,
 #endif
 
 static void WriteToStderr(const char* data) {
-  int old_errno = errno;
+  absl::base_internal::ErrnoSaver errno_saver;
   absl::raw_logging_internal::SafeWriteToStderr(data, strlen(data));
-  errno = old_errno;
 }
 
 static void WriteSignalMessage(int signo, void (*writerfn)(const char*)) {

absl/debugging/internal/address_is_readable.cc

@@ -35,10 +35,12 @@ ABSL_NAMESPACE_END
 #include <fcntl.h>
 #include <sys/syscall.h>
 #include <unistd.h>
+
 #include <atomic>
 #include <cerrno>
 #include <cstdint>
 
+#include "absl/base/internal/errno_saver.h"
 #include "absl/base/internal/raw_logging.h"
 
 namespace absl {
@@ -67,7 +69,7 @@ static void Unpack(uint64_t x, int *pid, int *read_fd, int *write_fd) {
 // This is a namespace-scoped variable for correct zero-initialization.
 static std::atomic<uint64_t> pid_and_fds;  // initially 0, an invalid pid.
 bool AddressIsReadable(const void *addr) {
-  int save_errno = errno;
+  absl::base_internal::ErrnoSaver errno_saver;
   // We test whether a byte is readable by using write().  Normally, this would
   // be done via a cached file descriptor to /dev/null, but linux fails to
   // check whether the byte is readable when the destination is /dev/null, so
@@ -126,7 +128,6 @@ bool AddressIsReadable(const void *addr) {
                                           std::memory_order_relaxed);
     }
   } while (errno == EBADF);
-  errno = save_errno;
   return bytes_written == 1;
 }