add entry point of test

Author: SoftJing1

libc/config/linux/aarch64/entrypoints.txt

@@ -245,6 +245,7 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.sys.mman.mlock2
     libc.src.sys.mman.mlockall
     libc.src.sys.mman.mmap
+    libc.src.sys.mman.mremap
     libc.src.sys.mman.mprotect
     libc.src.sys.mman.msync
     libc.src.sys.mman.munlock

libc/config/linux/x86_64/entrypoints.txt

@@ -244,6 +244,7 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.sys.mman.mlock2
     libc.src.sys.mman.mlockall
     libc.src.sys.mman.mmap
+    libc.src.sys.mman.mremap
     libc.src.sys.mman.mprotect
     libc.src.sys.mman.msync
     libc.src.sys.mman.munlock

libc/src/sys/mman/CMakeLists.txt

@@ -108,8 +108,8 @@ add_entrypoint_object(
 )
 
 add_entrypoint_object(
-  mremap,
-  ALIAS,
+  mremap
+  ALIAS
   DEPENDS
     .${LIBC_TARGET_OS}.mremap
 )

libc/src/sys/mman/linux/mremap.cpp

@@ -24,23 +24,18 @@ LLVM_LIBC_FUNCTION(void *, mremap,
                    (void *old_address, size_t old_size, size_t new_size,
                     int flags, ... /* void *new_address */)) {
 
-#ifdef SYS_mremap
-  long syscall_number = SYS_mremap;
-#else
-#error "mremap syscalls not available."
-#endif
   long ret = 0;
+  void *new_address = nullptr;
   if (flags & MREMAP_FIXED) {
-    void *arg;
     va_list varargs;
     va_start(varargs, flags);
-    arg = va_arg(varargs, void *);
+    new_address = va_arg(varargs, void *);
     va_end(varargs);
-    ret = LIBC_NAMESPACE::syscall_impl(syscall_number, old_address, old_size,
-                                       new_size, flags, arg);
+    ret = LIBC_NAMESPACE::syscall_impl<long>(SYS_mremap, old_address, old_size,
+                                             new_size, flags, new_address);
   } else {
-    ret = LIBC_NAMESPACE::syscall_impl(syscall_number, old_address, old_size,
-                                       new_size, flags);
+    ret = LIBC_NAMESPACE::syscall_impl<long>(SYS_mremap, old_address, old_size,
+                                             new_size, flags);
   }
   if (ret < 0 && ret > -EXEC_PAGESIZE) {
     libc_errno = static_cast<int>(-ret);

libc/src/sys/mman/mremap.h

@@ -1,5 +1,4 @@
-//===-- Implementation header for mremap function -----------------*- C++
-//-*-===//
+//===-- Implementation header for mremap function -------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.

libc/test/src/sys/mman/linux/mremap_test.cpp

@@ -8,6 +8,7 @@
 
 #include "src/errno/libc_errno.h"
 #include "src/sys/mman/mmap.h"
+#include "src/sys/mman/mremap.h"
 #include "src/sys/mman/munmap.h"
 #include "test/UnitTest/ErrnoSetterMatcher.h"
 #include "test/UnitTest/Test.h"