From 7b43d70be4fe9c3f9003b189e62e4f86a6a88516 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E5=B0=8F=E6=98=8E?=
 <7737673+caobug@users.noreply.github.com>
Date: Mon, 26 Jun 2023 19:47:48 +0800
Subject: [PATCH] unix: fix build for lower versions of Android (#4046)

Available since Android N (API level 24): getgrgid_r, preadv, pwritev

Refs: https://cs.android.com/android/platform/superproject/+/master:bionic/docs/status.md
---
 src/unix/core.c |  5 +++++
 src/unix/fs.c   | 17 +++++++++++------
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/src/unix/core.c b/src/unix/core.c
index 0756364f..25c5181f 100644
--- a/src/unix/core.c
+++ b/src/unix/core.c
@@ -1271,6 +1271,10 @@ static int uv__getpwuid_r(uv_passwd_t *pwd, uid_t uid) {
 
 
 int uv_os_get_group(uv_group_t* grp, uv_uid_t gid) {
+#if defined(__ANDROID__) && __ANDROID_API__ < 24
+  /* This function getgrgid_r() was added in Android N (level 24) */
+  return UV_ENOSYS;
+#else
   struct group gp;
   struct group* result;
   char* buf;
@@ -1347,6 +1351,7 @@ int uv_os_get_group(uv_group_t* grp, uv_uid_t gid) {
   uv__free(buf);
 
   return 0;
+#endif
 }
 
 
diff --git a/src/unix/fs.c b/src/unix/fs.c
index e9e323e7..6b051c12 100644
--- a/src/unix/fs.c
+++ b/src/unix/fs.c
@@ -55,6 +55,11 @@
 # define HAVE_PREADV 0
 #endif
 
+/* preadv() and pwritev() were added in Android N (level 24) */
+#if defined(__linux__) && !(defined(__ANDROID__) && __ANDROID_API__ < 24)
+# define TRY_PREADV 1
+#endif
+
 #if defined(__linux__)
 # include <sys/sendfile.h>
 #endif
@@ -456,7 +461,7 @@ static ssize_t uv__fs_preadv(uv_file fd,
 
 
 static ssize_t uv__fs_read(uv_fs_t* req) {
-#if defined(__linux__)
+#if TRY_PREADV
   static _Atomic int no_preadv;
 #endif
   unsigned int iovmax;
@@ -480,13 +485,13 @@ static ssize_t uv__fs_read(uv_fs_t* req) {
 #if HAVE_PREADV
     result = preadv(req->file, (struct iovec*) req->bufs, req->nbufs, req->off);
 #else
-# if defined(__linux__)
+# if TRY_PREADV
     if (atomic_load_explicit(&no_preadv, memory_order_relaxed)) retry:
 # endif
     {
       result = uv__fs_preadv(req->file, req->bufs, req->nbufs, req->off);
     }
-# if defined(__linux__)
+# if TRY_PREADV
     else {
       result = preadv(req->file,
                       (struct iovec*) req->bufs,
@@ -1156,7 +1161,7 @@ static ssize_t uv__fs_lutime(uv_fs_t* req) {
 
 
 static ssize_t uv__fs_write(uv_fs_t* req) {
-#if defined(__linux__)
+#if TRY_PREADV
   static _Atomic int no_pwritev;
 #endif
   ssize_t r;
@@ -1185,13 +1190,13 @@ static ssize_t uv__fs_write(uv_fs_t* req) {
 #if HAVE_PREADV
     r = pwritev(req->file, (struct iovec*) req->bufs, req->nbufs, req->off);
 #else
-# if defined(__linux__)
+# if TRY_PREADV
     if (atomic_load_explicit(&no_pwritev, memory_order_relaxed)) retry:
 # endif
     {
       r = pwrite(req->file, req->bufs[0].base, req->bufs[0].len, req->off);
     }
-# if defined(__linux__)
+# if TRY_PREADV
     else {
       r = pwritev(req->file,
                   (struct iovec*) req->bufs,