Googletest export

Remove the dependency on Objective C++ in iOS builds.

252ce9c52d introduced the use of
NSTemporaryDirectory() on iOS, which requires Core Foundation, and
Objective C++.

This CL replaces NSTemporaryDirectory() with an equivalent solution
(according to Apple's documentation at [1]) available to C/C++ code.
Avoiding Objective C++ and Core Foundation makes it easier to integrate
googletest in projects that can't use the supplied Bazel build files.

[1] https://developer.apple.com/library/archive/documentation/Security/Conceptual/SecureCodingGuide/Articles/RaceConditions.html#//apple_ref/doc/uid/TP40002585-SW10

PiperOrigin-RevId: 375474990

BUILD.bazel

@@ -56,12 +56,6 @@ config_setting(
     values = {"define": "absl=1"},
 )
 
-config_setting(
-    name = "ios",
-    values = {"apple_platform_type": "ios"},
-    visibility = [":__subpackages__"],
-)
-
 # Library that defines the FRIEND_TEST macro.
 cc_library(
     name = "gtest_prod",
@@ -92,10 +86,6 @@ cc_library(
         "googlemock/include/gmock/*.h",
     ]),
     copts = select({
-        ":ios": [
-            "-xobjective-c++",
-            "-pthread",
-        ],
         ":windows": [],
         "//conditions:default": ["-pthread"],
     }),

googletest/src/gtest-port.cc

@@ -80,10 +80,6 @@
 # include <zircon/syscalls.h>
 #endif  // GTEST_OS_FUCHSIA
 
-#if GTEST_OS_IOS
-#import <Foundation/Foundation.h>
-#endif  // GTEST_OS_IOS
-
 #include "gtest/gtest-spi.h"
 #include "gtest/gtest-message.h"
 #include "gtest/internal/gtest-internal.h"
@@ -692,8 +688,8 @@ class ThreadLocalRegistryImpl {
   static Mutex thread_map_mutex_;
 };
 
-Mutex ThreadLocalRegistryImpl::mutex_(Mutex::kStaticMutex);
+Mutex ThreadLocalRegistryImpl::mutex_(Mutex::kStaticMutex);  // NOLINT
-Mutex ThreadLocalRegistryImpl::thread_map_mutex_(Mutex::kStaticMutex);
+Mutex ThreadLocalRegistryImpl::thread_map_mutex_(Mutex::kStaticMutex);  // NOLINT
 
 ThreadLocalValueHolderBase* ThreadLocalRegistry::GetValueOnCurrentThread(
       const ThreadLocalBase* thread_local_instance) {
@@ -1099,9 +1095,9 @@ class CapturedStream {
     filename_ = temp_file_path;
 # else
     // There's no guarantee that a test has write access to the current
-    // directory, so we create the temporary file in the /tmp directory
+    // directory, so we create the temporary file in a temporary directory.
-    // instead. We use /tmp on most systems, and /sdcard on Android.
+    std::string name_template;
-    // That's because Android doesn't have /tmp.
+
 #  if GTEST_OS_LINUX_ANDROID
     // Note: Android applications are expected to call the framework's
     // Context.getExternalStorageDirectory() method through JNI to get
@@ -1114,23 +1110,46 @@ class CapturedStream {
     // The location /data/local/tmp is directly accessible from native code.
     // '/sdcard' and other variants cannot be relied on, as they are not
     // guaranteed to be mounted, or may have a delay in mounting.
-    char name_template[] = "/data/local/tmp/gtest_captured_stream.XXXXXX";
+    name_template = "/data/local/tmp/";
 #  elif GTEST_OS_IOS
-    NSString* temp_path = [NSTemporaryDirectory()
+    char user_temp_dir[PATH_MAX + 1];
-        stringByAppendingPathComponent:@"gtest_captured_stream.XXXXXX"];
 
-    char name_template[PATH_MAX + 1];
+    // Documented alternative to NSTemporaryDirectory() (for obtaining creating
-    strncpy(name_template, [temp_path UTF8String], PATH_MAX);
+    // a temporary directory) at
+    // https://developer.apple.com/library/archive/documentation/Security/Conceptual/SecureCodingGuide/Articles/RaceConditions.html#//apple_ref/doc/uid/TP40002585-SW10
+    //
+    // _CS_DARWIN_USER_TEMP_DIR (as well as _CS_DARWIN_USER_CACHE_DIR) is not
+    // documented in the confstr() man page at
+    // https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man3/confstr.3.html#//apple_ref/doc/man/3/confstr
+    // but are still available, according to the WebKit patches at
+    // https://trac.webkit.org/changeset/262004/webkit
+    // https://trac.webkit.org/changeset/263705/webkit
+    //
+    // The confstr() implementation falls back to getenv("TMPDIR"). See
+    // https://opensource.apple.com/source/Libc/Libc-1439.100.3/gen/confstr.c.auto.html
+    ::confstr(_CS_DARWIN_USER_TEMP_DIR, user_temp_dir, sizeof(user_temp_dir));
+
+    name_template = user_temp_dir;
+    if (name_template.back() != GTEST_PATH_SEP_[0])
+      name_template.push_back(GTEST_PATH_SEP_[0]);
 #  else
-    char name_template[] = "/tmp/captured_stream.XXXXXX";
+    name_template = "/tmp/";
 #  endif
-    const int captured_fd = mkstemp(name_template);
+    name_template.append("gtest_captured_stream.XXXXXX");
+
+    // mkstemp() modifies the string bytes in place, and does not go beyond the
+    // string's length. This results in well-defined behavior in C++17.
+    //
+    // The const_cast is needed below C++17. The constraints on std::string
+    // implementations in C++11 and above make assumption behind the const_cast
+    // fairly safe.
+    const int captured_fd = ::mkstemp(const_cast<char*>(name_template.data()));
     if (captured_fd == -1) {
       GTEST_LOG_(WARNING)
           << "Failed to create tmp file " << name_template
           << " for test; does the test have access to the /tmp directory?";
     }
-    filename_ = name_template;
+    filename_ = std::move(name_template);
 # endif  // GTEST_OS_WINDOWS
     fflush(nullptr);
     dup2(captured_fd, fd_);