From 9f525644df99cb2f7f81a23ca23840f0a8f82275 Mon Sep 17 00:00:00 2001
From: Elliott Hughes <enh@google.com>
Date: Tue, 8 Apr 2014 17:14:01 -0700
Subject: [PATCH] Implement _Exit(3).

Change-Id: Ida6ac844cc87d38c9645b197dd8188bb73e27dbe
---
 libc/SYSCALLS.TXT                 |  2 +-
 libc/arch-arm/syscalls/_exit.S    |  3 +++
 libc/arch-arm64/syscalls/_exit.S  |  3 +++
 libc/arch-mips/syscalls/_exit.S   |  3 +++
 libc/arch-mips64/syscalls/_exit.S |  3 +++
 libc/arch-x86/syscalls/_exit.S    |  3 +++
 libc/arch-x86_64/syscalls/_exit.S |  3 +++
 libc/include/stdlib.h             |  3 ++-
 tests/stdlib_test.cpp             | 14 ++++++++++++++
 tests/unistd_test.cpp             | 14 ++++++++++++++
 10 files changed, 49 insertions(+), 2 deletions(-)

diff --git a/libc/SYSCALLS.TXT b/libc/SYSCALLS.TXT
index e597b2f52..220c7139b 100644
--- a/libc/SYSCALLS.TXT
+++ b/libc/SYSCALLS.TXT
@@ -308,7 +308,7 @@ int __epoll_pwait:epoll_pwait(int, struct epoll_event*, int, int, const sigset_t
 
 int eventfd:eventfd2(unsigned int, int)  all
 
-void _exit:exit_group(int)  all
+void _exit|_Exit:exit_group(int)  all
 void __exit:exit(int)  all
 
 int futex(void*, int, int, void*, void*, int)  all
diff --git a/libc/arch-arm/syscalls/_exit.S b/libc/arch-arm/syscalls/_exit.S
index 1a6b35dcb..581b340e3 100644
--- a/libc/arch-arm/syscalls/_exit.S
+++ b/libc/arch-arm/syscalls/_exit.S
@@ -12,3 +12,6 @@ ENTRY(_exit)
     neg     r0, r0
     b       __set_errno
 END(_exit)
+
+    .globl _Exit
+    .equ _Exit, _exit
diff --git a/libc/arch-arm64/syscalls/_exit.S b/libc/arch-arm64/syscalls/_exit.S
index 24b7b17d0..40ada4863 100644
--- a/libc/arch-arm64/syscalls/_exit.S
+++ b/libc/arch-arm64/syscalls/_exit.S
@@ -19,3 +19,6 @@ ENTRY(_exit)
 
     ret
 END(_exit)
+
+    .globl _Exit
+    .equ _Exit, _exit
diff --git a/libc/arch-mips/syscalls/_exit.S b/libc/arch-mips/syscalls/_exit.S
index 5a0877da3..f546b66f6 100644
--- a/libc/arch-mips/syscalls/_exit.S
+++ b/libc/arch-mips/syscalls/_exit.S
@@ -17,3 +17,6 @@ ENTRY(_exit)
     nop
     .set reorder
 END(_exit)
+
+    .globl _Exit
+    .equ _Exit, _exit
diff --git a/libc/arch-mips64/syscalls/_exit.S b/libc/arch-mips64/syscalls/_exit.S
index 9b108a65b..eb84def8c 100644
--- a/libc/arch-mips64/syscalls/_exit.S
+++ b/libc/arch-mips64/syscalls/_exit.S
@@ -23,3 +23,6 @@ ENTRY(_exit)
     move ra, t0
     .set pop
 END(_exit)
+
+    .globl _Exit
+    .equ _Exit, _exit
diff --git a/libc/arch-x86/syscalls/_exit.S b/libc/arch-x86/syscalls/_exit.S
index 2ff5faf13..793c9d59c 100644
--- a/libc/arch-x86/syscalls/_exit.S
+++ b/libc/arch-x86/syscalls/_exit.S
@@ -20,3 +20,6 @@ ENTRY(_exit)
     popl    %ebx
     ret
 END(_exit)
+
+    .globl _Exit
+    .equ _Exit, _exit
diff --git a/libc/arch-x86_64/syscalls/_exit.S b/libc/arch-x86_64/syscalls/_exit.S
index f40cfe3f1..3c158976a 100644
--- a/libc/arch-x86_64/syscalls/_exit.S
+++ b/libc/arch-x86_64/syscalls/_exit.S
@@ -14,3 +14,6 @@ ENTRY(_exit)
 1:
     ret
 END(_exit)
+
+    .globl _Exit
+    .equ _Exit, _exit
diff --git a/libc/include/stdlib.h b/libc/include/stdlib.h
index 5dbcb3d7d..2c797c593 100644
--- a/libc/include/stdlib.h
+++ b/libc/include/stdlib.h
@@ -41,8 +41,9 @@ __BEGIN_DECLS
 #define EXIT_FAILURE 1
 #define EXIT_SUCCESS 0
 
-extern __noreturn void exit(int);
 extern __noreturn void abort(void);
+extern __noreturn void exit(int);
+extern __noreturn void _Exit(int);
 extern int atexit(void (*)(void));
 
 extern char *getenv(const char *);
diff --git a/tests/stdlib_test.cpp b/tests/stdlib_test.cpp
index 3a3fe28ae..bb395f04f 100644
--- a/tests/stdlib_test.cpp
+++ b/tests/stdlib_test.cpp
@@ -202,3 +202,17 @@ TEST(stdlib, strtof) {
 TEST(stdlib, strtold) {
   ASSERT_DOUBLE_EQ(1.23, strtold("1.23", NULL));
 }
+
+TEST(unistd, _Exit) {
+  int pid = fork();
+  ASSERT_NE(-1, pid) << strerror(errno);
+
+  if (pid == 0) {
+    _Exit(99);
+  }
+
+  int status;
+  ASSERT_EQ(pid, waitpid(pid, &status, 0));
+  ASSERT_TRUE(WIFEXITED(status));
+  ASSERT_EQ(99, WEXITSTATUS(status));
+}
diff --git a/tests/unistd_test.cpp b/tests/unistd_test.cpp
index f50c102f6..da8fd4b7b 100644
--- a/tests/unistd_test.cpp
+++ b/tests/unistd_test.cpp
@@ -116,3 +116,17 @@ TEST(unistd, read_EBADF) {
 TEST(unistd, alarm) {
   ASSERT_EQ(0U, alarm(0));
 }
+
+TEST(unistd, _exit) {
+  int pid = fork();
+  ASSERT_NE(-1, pid) << strerror(errno);
+
+  if (pid == 0) {
+    _exit(99);
+  }
+
+  int status;
+  ASSERT_EQ(pid, waitpid(pid, &status, 0));
+  ASSERT_TRUE(WIFEXITED(status));
+  ASSERT_EQ(99, WEXITSTATUS(status));
+}