Cleanup libc hacks

build.py

@@ -554,7 +554,7 @@ def setup_ndk(args):
         )
         if not op.exists(lib_dir):
             continue
-        src_dir = op.join("tools", "ndk-bins", "21", arch)
+        src_dir = op.join("tools", "ndk-bins", arch)
         rm(op.join(src_dir, ".DS_Store"))
         shutil.copytree(src_dir, lib_dir, copy_function=cp, dirs_exist_ok=True)
 

native/src/base/Android.mk

@@ -22,8 +22,8 @@ include $(BUILD_STATIC_LIBRARY)
 
 include $(CLEAR_VARS)
 LOCAL_MODULE := libcompat
-# Workaround "hacky" libc.a missing symbols
-# To build Magisk with vanilla NDK, comment out the next line
+# Add "hacky" libc.a missing symbols back
+# All symbols in this library are weak, so a vanilla NDK should still link properly
 LOCAL_SRC_FILES := compat/compat.cpp
 # Fix static variables' ctor/dtor when using LTO
 # See: https://github.com/android/ndk/issues/1461

native/src/base/compat/compat.cpp

@@ -1,18 +1,19 @@
-// This file implements all missing symbols that should exist in normal API 21
+// This file implements all missing symbols that should exist in normal API 23
 // libc.a but missing in our extremely lean libc.a replacements.
 
+#if !defined(__LP64__)
+
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
-#include <mntent.h>
 #include <unistd.h>
 #include <fcntl.h>
 #include <sys/syscall.h>
-#include <sys/stat.h>
 
-#if !defined(__LP64__)
 extern "C" {
 
+#include "fortify.hpp"
+
 // Original source: https://github.com/freebsd/freebsd/blob/master/contrib/file/src/getline.c
 // License: BSD, full copyright notice please check original source
 
@@ -58,41 +59,8 @@ ssize_t getline(char **buf, size_t *bufsiz, FILE *fp) {
     return getdelim(buf, bufsiz, '\n', fp);
 }
 
-[[gnu::weak]]
-FILE *setmntent(const char *path, const char *mode) {
-    return fopen(path, mode);
-}
-
-[[gnu::weak]]
-int endmntent(FILE *fp) {
-    if (fp != nullptr) {
-        fclose(fp);
-    }
-    return 1;
-}
-
 // Missing system call wrappers
 
-[[gnu::weak]]
-int setns(int fd, int nstype) {
-    return syscall(__NR_setns, fd, nstype);
-}
-
-[[gnu::weak]]
-int unshare(int flags) {
-    return syscall(__NR_unshare, flags);
-}
-
-[[gnu::weak]]
-int accept4(int sockfd, struct sockaddr *addr, socklen_t *addrlen, int flags) {
-    return syscall(__NR_accept4, sockfd, addr, addrlen, flags);
-}
-
-[[gnu::weak]]
-int dup3(int oldfd, int newfd, int flags) {
-    return syscall(__NR_dup3, oldfd, newfd, flags);
-}
-
 [[gnu::weak]]
 ssize_t readlinkat(int dirfd, const char *pathname, char *buf, size_t bufsiz) {
     return syscall(__NR_readlinkat, dirfd, pathname, buf, bufsiz);
@@ -109,11 +77,6 @@ int linkat(int olddirfd, const char *oldpath,
     return syscall(__NR_linkat, olddirfd, oldpath, newdirfd, newpath, flags);
 }
 
-[[gnu::weak]]
-int inotify_init1(int flags) {
-    return syscall(__NR_inotify_init1, flags);
-}
-
 [[gnu::weak]]
 int faccessat(int dirfd, const char *pathname, int mode, int flags) {
     return syscall(__NR_faccessat, dirfd, pathname, mode, flags);
@@ -142,34 +105,6 @@ int ftruncate64(int fd, off64_t length) {
 [[gnu::weak]]
 void android_set_abort_message(const char *) {}
 
-// Original source: <android/legacy_signal_inlines.h>
-[[gnu::weak]]
-int sigaddset(sigset_t *set, int signum) {
-    /* Signal numbers start at 1, but bit positions start at 0. */
-    int bit = signum - 1;
-    auto *local_set = (unsigned long *)set;
-    if (set == nullptr || bit < 0 || bit >= (int)(8 * sizeof(sigset_t))) {
-        errno = EINVAL;
-        return -1;
-    }
-    local_set[bit / LONG_BIT] |= 1UL << (bit % LONG_BIT);
-    return 0;
-}
-
-[[gnu::weak]]
-int sigemptyset(sigset_t *set) {
-    if (set == nullptr) {
-        errno = EINVAL;
-        return -1;
-    }
-    memset(set, 0, sizeof(sigset_t));
-    return 0;
-}
-
-#undef vsnprintf
-#undef snprintf
-#include "fortify.hpp"
-
 extern FILE __sF[];
 
 [[gnu::weak]] FILE* stdin = &__sF[0];

native/src/base/new.cpp

@@ -1,14 +1,14 @@
 #include <new>
-#include <stdlib.h>
+#include <cstdlib>
 
 /* Override libc++ new implementation
  * to optimize final build size */
 
-void* operator new(std::size_t s) { return malloc(s); }
-void* operator new[](std::size_t s) { return malloc(s); }
-void  operator delete(void *p) { free(p); }
-void  operator delete[](void *p) { free(p); }
-void* operator new(std::size_t s, const std::nothrow_t&) noexcept { return malloc(s); }
-void* operator new[](std::size_t s, const std::nothrow_t&) noexcept { return malloc(s); }
-void  operator delete(void *p, const std::nothrow_t&) noexcept { free(p); }
-void  operator delete[](void *p, const std::nothrow_t&) noexcept { free(p); }
+void* operator new(std::size_t s) { return std::malloc(s); }
+void* operator new[](std::size_t s) { return std::malloc(s); }
+void  operator delete(void *p) { std::free(p); }
+void  operator delete[](void *p) { std::free(p); }
+void* operator new(std::size_t s, const std::nothrow_t&) noexcept { return std::malloc(s); }
+void* operator new[](std::size_t s, const std::nothrow_t&) noexcept { return std::malloc(s); }
+void  operator delete(void *p, const std::nothrow_t&) noexcept { std::free(p); }
+void  operator delete[](void *p, const std::nothrow_t&) noexcept { std::free(p); }