[libc] implement quick exit function

libc/config/linux/x86_64/entrypoints.txt

@@ -730,6 +730,7 @@ if(LLVM_LIBC_FULL_BUILD)
     libc.src.stdlib.abort
     libc.src.stdlib.atexit
     libc.src.stdlib.exit
+    libc.src.stdlib.quick_exit
     libc.src.stdlib.getenv
 
     # signal.h entrypoints

libc/spec/stdc.td

@@ -1071,6 +1071,7 @@ 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>]>,
       ]
   >;
 

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

libc/src/__support/OSUtil/baremetal/quick_exit.cpp → libc/src/__support/OSUtil/baremetal/exit.cpp

@@ -1,18 +1,21 @@
-//===----- 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.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
-#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);
 
 namespace LIBC_NAMESPACE {
+namespace internal {
 
-[[noreturn]] void quick_exit(int status) { __llvm_libc_quick_exit(status); }
+[[noreturn]] void exit(int status) { __llvm_libc_quick_exit(status); }
+
+} // namespace internal
 
 } // namespace LIBC_NAMESPACE

libc/src/__support/OSUtil/quick_exit.h → libc/src/__support/OSUtil/exit.h

@@ -6,13 +6,16 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef LLVM_LIBC_SRC___SUPPORT_OSUTIL_QUICK_EXIT_H
-#define LLVM_LIBC_SRC___SUPPORT_OSUTIL_QUICK_EXIT_H
+#ifndef LLVM_LIBC_SRC___SUPPORT_OSUTIL_EXIT_H
+#define LLVM_LIBC_SRC___SUPPORT_OSUTIL_EXIT_H
 
 namespace LIBC_NAMESPACE {
+namespace internal {
 
-[[noreturn]] void quick_exit(int status);
+[[noreturn]] void exit(int status);
 
 }
 
+} // namespace LIBC_NAMESPACE
+
 #endif // LLVM_LIBC_SRC___SUPPORT_OSUTIL_QUICK_EXIT_H

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

libc/src/__support/OSUtil/gpu/quick_exit.cpp → libc/src/__support/OSUtil/gpu/exit.cpp

@@ -6,14 +6,15 @@
 //
 //===----------------------------------------------------------------------===//
 
-#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 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 +26,5 @@ namespace LIBC_NAMESPACE {
   gpu::end_program();
 }
 
+} // namespace internal
 } // namespace LIBC_NAMESPACE

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

libc/src/__support/OSUtil/linux/quick_exit.cpp → libc/src/__support/OSUtil/linux/exit.cpp

@@ -10,19 +10,17 @@
 #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.
 #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

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
 
@@ -56,6 +56,7 @@ LIBC_INLINE void report_assertion_failure(const char *assertion,
 // __builtin_trap as it could potentially be implemented using illegal
 // instructions which can be very misleading when debugging.
 #ifdef NDEBUG
+
 #define LIBC_ASSERT(COND)                                                      \
   do {                                                                         \
   } while (false)
@@ -76,7 +77,7 @@ 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

libc/src/stdlib/CMakeLists.txt

@@ -432,6 +432,17 @@ add_entrypoint_object(
     ._Exit
     .atexit
     libc.src.__support.OSUtil.osutil
+
+)
+
+add_entrypoint_object(
+  quick_exit
+  SRCS
+    quick_exit.cpp
+  HDRS
+    quick_exit.h
+  DEPENDS
+    libc.src.__support.OSUtil.osutil
 )
 
 add_entrypoint_object(

libc/src/stdlib/_Exit.cpp

@@ -6,15 +6,15 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "src/__support/OSUtil/quick_exit.h"
+#include "src/__support/OSUtil/exit.h"
 #include "src/__support/common.h"
 
 #include "src/stdlib/_Exit.h"
 
 namespace LIBC_NAMESPACE {
 
 [[noreturn]] LLVM_LIBC_FUNCTION(void, _Exit, (int status)) {
-  quick_exit(status);
+  internal::exit(status);
 }
 
 } // namespace LIBC_NAMESPACE

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

libc/src/stdlib/quick_exit.cpp

@@ -0,0 +1,21 @@
+//===-- 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

libc/src/stdlib/quick_exit.h

@@ -0,0 +1,17 @@
+//===-- 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.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#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_STDLIB_QUICK_EXIT_H

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

libc/test/IntegrationTest/test.h

@@ -9,40 +9,40 @@
 #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)                             \
   if (!(val)) {                                                                \
     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)                            \
   if (val) {                                                                   \
     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)                        \
   if ((val1) != (val2)) {                                                      \
     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)                        \
   if ((val1) == (val2)) {                                                      \
     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);                                     \
   }
 
 ////////////////////////////////////////////////////////////////////////////////

libc/test/src/stdlib/CMakeLists.txt

@@ -324,6 +324,19 @@ add_libc_test(
     libc.src.stdlib.srand
 )
 
+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
+  )
+
 if(LLVM_LIBC_FULL_BUILD)
 
   add_libc_test(

libc/test/src/stdlib/quick_exit_test.cpp

@@ -0,0 +1,15 @@
+//===-- 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/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);
+}

utils/bazel/llvm-project-overlay/libc/BUILD.bazel

@@ -630,7 +630,7 @@ libc_support_library(
         ":__support_integer_to_string",
         ":__support_macros_attributes",
         ":__support_osutil_io",
-        ":__support_osutil_quick_exit",
+        ":__support_osutil_exit",
     ],
 )
 
@@ -1062,9 +1062,9 @@ libc_support_library(
 )
 
 libc_support_library(
-    name = "__support_osutil_quick_exit",
-    srcs = ["src/__support/OSUtil/linux/quick_exit.cpp"],
-    hdrs = ["src/__support/OSUtil/quick_exit.h"],
+    name = "__support_osutil_exit",
+    srcs = ["src/__support/OSUtil/linux/exit.cpp"],
+    hdrs = ["src/__support/OSUtil/exit.h"],
     target_compatible_with = select({
         "@platforms//os:linux": [],
         "//conditions:default": ["@platforms//:incompatible"],