[libc] added quick_exit function (#93620)

- In /libc/src/__support/ OSUtil, changed quick_exit to just exit, and
put in namespace
LIBC_NAMESPACE::internal.
- In /libc/src/stdlib added quick_exit
- Added test files for quick_exit

19 files changed, 121 insertions, 40 deletions

diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index 699bb9d..367db7d3 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -173,6 +173,7 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.stdlib.atoll
     libc.src.stdlib.bsearch
     libc.src.stdlib.div
+    libc.src.stdlib.quick_exit
     libc.src.stdlib.labs
     libc.src.stdlib.ldiv
     libc.src.stdlib.llabs
diff --git a/libc/spec/stdc.td b/libc/spec/stdc.td
index ff70025..109721b 100644
--- a/libc/spec/stdc.td
+++ b/libc/spec/stdc.td
@@ -1072,6 +1072,7 @@ def StdC : StandardSpec<"stdc"> {
           FunctionSpec<"_Exit", RetValSpec<NoReturn>, [ArgSpec<IntType>]>,
           FunctionSpec<"exit", RetValSpec<NoReturn>, [ArgSpec<IntType>]>,
           FunctionSpec<"atexit", RetValSpec<IntType>, [ArgSpec<AtexitHandlerT>]>,
+          FunctionSpec<"quick_exit", RetValSpec<NoReturn>, [ArgSpec<IntType>]>,
       ]
   >;
 
diff --git a/libc/src/__support/OSUtil/baremetal/CMakeLists.txt b/libc/src/__support/OSUtil/baremetal/CMakeLists.txt
index e78301d..8f9200a 100644
--- a/libc/src/__support/OSUtil/baremetal/CMakeLists.txt
+++ b/libc/src/__support/OSUtil/baremetal/CMakeLists.txt
@@ -2,7 +2,7 @@ add_object_library(
   baremetal_util
   SRCS
     io.cpp
-    quick_exit.cpp
+    exit.cpp
   HDRS
     io.h
   DEPENDS
diff --git a/libc/src/__support/OSUtil/baremetal/quick_exit.cpp b/libc/src/__support/OSUtil/baremetal/exit.cpp
index 5b6fcf4..08473f7 100644
--- a/libc/src/__support/OSUtil/baremetal/quick_exit.cpp
+++ b/libc/src/__support/OSUtil/baremetal/exit.cpp
@@ -1,4 +1,4 @@
-//===----- Baremetal implementation of a quick exit function ----*- C++ -*-===//
+//===-------- Baremetal implementation of an exit function ------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -6,13 +6,13 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "src/__support/OSUtil/quick_exit.h"
+#include "src/__support/OSUtil/exit.h"
 
 // This is intended to be provided by the vendor.
-extern "C" [[noreturn]] void __llvm_libc_quick_exit(int status);
+extern "C" [[noreturn]] void __llvm_libc_exit(int status);
 
-namespace LIBC_NAMESPACE {
+namespace LIBC_NAMESPACE::internal {
 
-[[noreturn]] void quick_exit(int status) { __llvm_libc_quick_exit(status); }
+[[noreturn]] void exit(int status) { __llvm_libc_exit(status); }
 
-} // namespace LIBC_NAMESPACE
+} // namespace LIBC_NAMESPACE::internal
diff --git a/libc/src/__support/OSUtil/exit.h b/libc/src/__support/OSUtil/exit.h
new file mode 100644
index 0000000..f01e4c7
--- /dev/null
+++ b/libc/src/__support/OSUtil/exit.h
@@ -0,0 +1,18 @@
+//===------------ Implementation of an exit function ------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC___SUPPORT_OSUTIL_EXIT_H
+#define LLVM_LIBC_SRC___SUPPORT_OSUTIL_EXIT_H
+
+namespace LIBC_NAMESPACE::internal {
+
+[[noreturn]] void exit(int status);
+
+}
+
+#endif // LLVM_LIBC_SRC___SUPPORT_OSUTIL_EXIT_H
diff --git a/libc/src/__support/OSUtil/gpu/CMakeLists.txt b/libc/src/__support/OSUtil/gpu/CMakeLists.txt
index 0c89f92..6cb3aa3 100644
--- a/libc/src/__support/OSUtil/gpu/CMakeLists.txt
+++ b/libc/src/__support/OSUtil/gpu/CMakeLists.txt
@@ -1,7 +1,7 @@
 add_object_library(
   gpu_util
   SRCS
-    quick_exit.cpp
+    exit.cpp
     io.cpp
   HDRS
     io.h
diff --git a/libc/src/__support/OSUtil/gpu/quick_exit.cpp b/libc/src/__support/OSUtil/gpu/exit.cpp
index af47959..96acb54 100644
--- a/libc/src/__support/OSUtil/gpu/quick_exit.cpp
+++ b/libc/src/__support/OSUtil/gpu/exit.cpp
@@ -1,4 +1,4 @@
-//===---------- GPU implementation of a quick exit function -----*- C++ -*-===//
+//===------------- GPU implementation of an exit function -------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -6,14 +6,14 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "src/__support/OSUtil/quick_exit.h"
+#include "src/__support/OSUtil/exit.h"
 
 #include "src/__support/RPC/rpc_client.h"
 #include "src/__support/macros/properties/architectures.h"
 
-namespace LIBC_NAMESPACE {
+namespace LIBC_NAMESPACE::internal {
 
-[[noreturn]] void quick_exit(int status) {
+[[noreturn]] void exit(int status) {
   // We want to first make sure the server is listening before we exit.
   rpc::Client::Port port = rpc::client.open<RPC_EXIT>();
   port.send_and_recv([](rpc::Buffer *) {}, [](rpc::Buffer *) {});
@@ -25,4 +25,4 @@ namespace LIBC_NAMESPACE {
   gpu::end_program();
 }
 
-} // namespace LIBC_NAMESPACE
+} // namespace LIBC_NAMESPACE::internal
diff --git a/libc/src/__support/OSUtil/linux/CMakeLists.txt b/libc/src/__support/OSUtil/linux/CMakeLists.txt
index 239d115..9a55232 100644
--- a/libc/src/__support/OSUtil/linux/CMakeLists.txt
+++ b/libc/src/__support/OSUtil/linux/CMakeLists.txt
@@ -7,7 +7,7 @@ add_subdirectory(${LIBC_TARGET_ARCHITECTURE})
 add_object_library(
   linux_util
   SRCS
-    quick_exit.cpp
+    exit.cpp
   HDRS
     io.h
     syscall.h
diff --git a/libc/src/__support/OSUtil/linux/quick_exit.cpp b/libc/src/__support/OSUtil/linux/exit.cpp
index 51b3231..ee90415 100644
--- a/libc/src/__support/OSUtil/linux/quick_exit.cpp
+++ b/libc/src/__support/OSUtil/linux/exit.cpp
@@ -1,4 +1,4 @@
-//===---------- Linux implementation of a quick exit function ---*- C++ -*-===//
+//===------------ Linux implementation of an exit function ------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -10,19 +10,19 @@
 #include "syscall.h"     // For internal syscall function.
 #include <sys/syscall.h> // For syscall numbers.
 
-namespace LIBC_NAMESPACE {
+namespace LIBC_NAMESPACE::internal {
 
 // mark as no_stack_protector for x86 since TLS can be torn down before calling
-// quick_exit so that the stack protector canary cannot be loaded.
+// exit so that the stack protector canary cannot be loaded.
 #ifdef LIBC_TARGET_ARCH_IS_X86
-__attribute__((no_stack_protector))
+[[clang::no_stack_protector]]
 #endif
-__attribute__((noreturn)) void
-quick_exit(int status) {
+[[noreturn]] void
+exit(int status) {
   for (;;) {
     LIBC_NAMESPACE::syscall_impl<long>(SYS_exit_group, status);
     LIBC_NAMESPACE::syscall_impl<long>(SYS_exit, status);
   }
 }
 
-} // namespace LIBC_NAMESPACE
+} // namespace LIBC_NAMESPACE::internal
diff --git a/libc/src/__support/libc_assert.h b/libc/src/__support/libc_assert.h
index 61f0754..ed06cc3 100644
--- a/libc/src/__support/libc_assert.h
+++ b/libc/src/__support/libc_assert.h
@@ -20,8 +20,8 @@
 
 #else // Not LIBC_COPT_USE_C_ASSERT
 
+#include "src/__support/OSUtil/exit.h"
 #include "src/__support/OSUtil/io.h"
-#include "src/__support/OSUtil/quick_exit.h"
 #include "src/__support/integer_to_string.h"
 #include "src/__support/macros/attributes.h" // For LIBC_INLINE
 
@@ -51,7 +51,7 @@ LIBC_INLINE void report_assertion_failure(const char *assertion,
 
 // The public "assert" macro calls abort on failure. Should it be same here?
 // The libc internal assert can fire from anywhere inside the libc. So, to
-// avoid potential chicken-and-egg problems, it is simple to do a quick_exit
+// avoid potential chicken-and-egg problems, it is simple to do an exit
 // on assertion failure instead of calling abort. We also don't want to use
 // __builtin_trap as it could potentially be implemented using illegal
 // instructions which can be very misleading when debugging.
@@ -76,7 +76,7 @@ LIBC_INLINE void report_assertion_failure(const char *assertion,
                                                "' in function: '");            \
       LIBC_NAMESPACE::write_to_stderr(__PRETTY_FUNCTION__);                    \
       LIBC_NAMESPACE::write_to_stderr("'\n");                                  \
-      LIBC_NAMESPACE::quick_exit(0xFF);                                        \
+      LIBC_NAMESPACE::internal::exit(0xFF);                                    \
     }                                                                          \
   } while (false)
 #endif // NDEBUG
diff --git a/libc/src/stdlib/CMakeLists.txt b/libc/src/stdlib/CMakeLists.txt
index 9b76a6a..e0bff51 100644
--- a/libc/src/stdlib/CMakeLists.txt
+++ b/libc/src/stdlib/CMakeLists.txt
@@ -43,6 +43,16 @@ add_entrypoint_object(
 )
 
 add_entrypoint_object(
+  quick_exit
+  SRCS
+    quick_exit.cpp
+  HDRS
+    quick_exit.h
+  DEPENDS
+    libc.src.__support.OSUtil.osutil
+)
+
+add_entrypoint_object(
   getenv
   SRCS
     getenv.cpp
diff --git a/libc/src/stdlib/_Exit.cpp b/libc/src/stdlib/_Exit.cpp
index 233af20..03a7662 100644
--- a/libc/src/stdlib/_Exit.cpp
+++ b/libc/src/stdlib/_Exit.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "src/__support/OSUtil/quick_exit.h"
+#include "src/__support/OSUtil/exit.h"
 #include "src/__support/common.h"
 
 #include "src/stdlib/_Exit.h"
@@ -14,7 +14,7 @@
 namespace LIBC_NAMESPACE {
 
 [[noreturn]] LLVM_LIBC_FUNCTION(void, _Exit, (int status)) {
-  quick_exit(status);
+  internal::exit(status);
 }
 
 } // namespace LIBC_NAMESPACE
diff --git a/libc/src/stdlib/exit.cpp b/libc/src/stdlib/exit.cpp
index ba87bff..1f7ccbb 100644
--- a/libc/src/stdlib/exit.cpp
+++ b/libc/src/stdlib/exit.cpp
@@ -7,7 +7,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "src/stdlib/exit.h"
-#include "src/__support/OSUtil/quick_exit.h"
+#include "src/__support/OSUtil/exit.h"
 #include "src/__support/common.h"
 
 extern "C" void __cxa_finalize(void *);
@@ -16,7 +16,7 @@ namespace LIBC_NAMESPACE {
 
 [[noreturn]] LLVM_LIBC_FUNCTION(void, exit, (int status)) {
   __cxa_finalize(nullptr);
-  quick_exit(status);
+  internal::exit(status);
 }
 
 } // namespace LIBC_NAMESPACE
diff --git a/libc/src/stdlib/quick_exit.cpp b/libc/src/stdlib/quick_exit.cpp
new file mode 100644
index 0000000..cf7f07b
--- /dev/null
+++ b/libc/src/stdlib/quick_exit.cpp
@@ -0,0 +1,22 @@
+//===-- Implementation of quick_exit --------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/stdlib/quick_exit.h"
+#include "src/__support/OSUtil/exit.h"
+#include "src/__support/common.h"
+
+// extern "C" void __cxa_finalize(void *);
+
+namespace LIBC_NAMESPACE {
+
+[[noreturn]] LLVM_LIBC_FUNCTION(void, quick_exit, (int status)) {
+  // __cxa_finalize(nullptr);
+  internal::exit(status);
+}
+
+} // namespace LIBC_NAMESPACE
diff --git a/libc/src/__support/OSUtil/quick_exit.h b/libc/src/stdlib/quick_exit.h
index e445917..9a3c20c 100644
--- a/libc/src/__support/OSUtil/quick_exit.h
+++ b/libc/src/stdlib/quick_exit.h
@@ -1,4 +1,4 @@
-//===---------- Implementation of a quick exit function ---------*- C++ -*-===//
+//===-- Implementation header for quick_exit --------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -6,13 +6,13 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef LLVM_LIBC_SRC___SUPPORT_OSUTIL_QUICK_EXIT_H
-#define LLVM_LIBC_SRC___SUPPORT_OSUTIL_QUICK_EXIT_H
+#ifndef LLVM_LIBC_SRC_STDLIB_QUICK_EXIT_H
+#define LLVM_LIBC_SRC_STDLIB_QUICK_EXIT_H
 
 namespace LIBC_NAMESPACE {
 
 [[noreturn]] void quick_exit(int status);
 
-}
+} // namespace LIBC_NAMESPACE
 
-#endif // LLVM_LIBC_SRC___SUPPORT_OSUTIL_QUICK_EXIT_H
+#endif // LLVM_LIBC_SRC_STDLIB_QUICK_EXIT_H
diff --git a/libc/src/unistd/_exit.cpp b/libc/src/unistd/_exit.cpp
index 6fbf3a5..4b652a2 100644
--- a/libc/src/unistd/_exit.cpp
+++ b/libc/src/unistd/_exit.cpp
@@ -7,13 +7,13 @@
 //===----------------------------------------------------------------------===//
 
 #include "src/unistd/_exit.h"
-#include "src/__support/OSUtil/quick_exit.h"
+#include "src/__support/OSUtil/exit.h"
 #include "src/__support/common.h"
 
 namespace LIBC_NAMESPACE {
 
 [[noreturn]] LLVM_LIBC_FUNCTION(void, _exit, (int status)) {
-  quick_exit(status);
+  internal::exit(status);
 }
 
 } // namespace LIBC_NAMESPACE
diff --git a/libc/test/IntegrationTest/test.h b/libc/test/IntegrationTest/test.h
index 64906ef..5be66d9 100644
--- a/libc/test/IntegrationTest/test.h
+++ b/libc/test/IntegrationTest/test.h
@@ -9,8 +9,8 @@
 #ifndef LLVM_LIBC_UTILS_INTEGRATION_TEST_TEST_H
 #define LLVM_LIBC_UTILS_INTEGRATION_TEST_TEST_H
 
+#include "src/__support/OSUtil/exit.h"
 #include "src/__support/OSUtil/io.h"
-#include "src/__support/OSUtil/quick_exit.h"
 
 #define __AS_STRING(val) #val
 #define __CHECK_TRUE(file, line, val, should_exit)                             \
@@ -18,7 +18,7 @@
     LIBC_NAMESPACE::write_to_stderr(file ":" __AS_STRING(                      \
         line) ": Expected '" #val "' to be true, but is false\n");             \
     if (should_exit)                                                           \
-      LIBC_NAMESPACE::quick_exit(127);                                         \
+      LIBC_NAMESPACE::internal::exit(127);                                     \
   }
 
 #define __CHECK_FALSE(file, line, val, should_exit)                            \
@@ -26,7 +26,7 @@
     LIBC_NAMESPACE::write_to_stderr(file ":" __AS_STRING(                      \
         line) ": Expected '" #val "' to be false, but is true\n");             \
     if (should_exit)                                                           \
-      LIBC_NAMESPACE::quick_exit(127);                                         \
+      LIBC_NAMESPACE::internal::exit(127);                                     \
   }
 
 #define __CHECK_EQ(file, line, val1, val2, should_exit)                        \
@@ -34,7 +34,7 @@
     LIBC_NAMESPACE::write_to_stderr(file ":" __AS_STRING(                      \
         line) ": Expected '" #val1 "' to be equal to '" #val2 "'\n");          \
     if (should_exit)                                                           \
-      LIBC_NAMESPACE::quick_exit(127);                                         \
+      LIBC_NAMESPACE::internal::exit(127);                                     \
   }
 
 #define __CHECK_NE(file, line, val1, val2, should_exit)                        \
@@ -42,7 +42,7 @@
     LIBC_NAMESPACE::write_to_stderr(file ":" __AS_STRING(                      \
         line) ": Expected '" #val1 "' to not be equal to '" #val2 "'\n");      \
     if (should_exit)                                                           \
-      LIBC_NAMESPACE::quick_exit(127);                                         \
+      LIBC_NAMESPACE::internal::exit(127);                                     \
   }
 
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/libc/test/src/stdlib/CMakeLists.txt b/libc/test/src/stdlib/CMakeLists.txt
index 28c5b56..6a7faed 100644
--- a/libc/test/src/stdlib/CMakeLists.txt
+++ b/libc/test/src/stdlib/CMakeLists.txt
@@ -373,6 +373,19 @@ if(LLVM_LIBC_FULL_BUILD)
       libc.src.signal.raise
   )
 
+  add_libc_test(
+    quick_exit_test
+    # The EXPECT_EXITS test is only availible for unit tests.
+    UNIT_TEST_ONLY
+    SUITE
+      libc-stdlib-tests
+    SRCS
+      quick_exit_test.cpp
+    DEPENDS
+      libc.include.stdlib
+      libc.src.stdlib.quick_exit
+  )
+
   # Only the GPU has an in-tree 'malloc' implementation.
   if(LIBC_TARGET_OS_IS_GPU)
     add_libc_test(
diff --git a/libc/test/src/stdlib/quick_exit_test.cpp b/libc/test/src/stdlib/quick_exit_test.cpp
new file mode 100644
index 0000000..3af7c74
--- /dev/null
+++ b/libc/test/src/stdlib/quick_exit_test.cpp
@@ -0,0 +1,16 @@
+//===-- Unittests for quick_exit ------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/stdlib/exit.h"
+#include "src/stdlib/quick_exit.h"
+#include "test/UnitTest/Test.h"
+
+TEST(LlvmLibcStdlib, quick_exit) {
+  EXPECT_EXITS([] { LIBC_NAMESPACE::quick_exit(1); }, 1);
+  EXPECT_EXITS([] { LIBC_NAMESPACE::quick_exit(65); }, 65);
+}