13 files changed, 344 insertions, 6 deletions

diff --git a/src/common/CMakeLists.txt b/src/common/CMakeLists.txt
index 13ed68b3f..efc4a9fe9 100644
--- a/src/common/CMakeLists.txt
+++ b/src/common/CMakeLists.txt
@@ -155,6 +155,14 @@ if (WIN32)
   target_link_libraries(common PRIVATE ntdll)
 endif()
 
+if(ANDROID)
+    target_sources(common
+        PRIVATE
+            fs/fs_android.cpp
+            fs/fs_android.h
+    )
+endif()
+
 if(ARCHITECTURE_x86_64)
     target_sources(common
         PRIVATE
@@ -194,6 +202,11 @@ create_target_directory_groups(common)
 target_link_libraries(common PUBLIC Boost::context Boost::headers fmt::fmt microprofile Threads::Threads)
 target_link_libraries(common PRIVATE lz4::lz4 zstd::zstd LLVM::Demangle)
 
+if (ANDROID)
+    # For ASharedMemory_create
+    target_link_libraries(common PRIVATE android)
+endif()
+
 if (YUZU_USE_PRECOMPILED_HEADERS)
     target_precompile_headers(common PRIVATE precompiled_headers.h)
 endif()
diff --git a/src/common/dynamic_library.cpp b/src/common/dynamic_library.cpp
index 054277a2b..4fabe7e52 100644
--- a/src/common/dynamic_library.cpp
+++ b/src/common/dynamic_library.cpp
@@ -22,6 +22,8 @@ DynamicLibrary::DynamicLibrary(const char* filename) {
     void(Open(filename));
 }
 
+DynamicLibrary::DynamicLibrary(void* handle_) : handle{handle_} {}
+
 DynamicLibrary::DynamicLibrary(DynamicLibrary&& rhs) noexcept
     : handle{std::exchange(rhs.handle, nullptr)} {}
 
diff --git a/src/common/dynamic_library.h b/src/common/dynamic_library.h
index f42bdf441..662d454d4 100644
--- a/src/common/dynamic_library.h
+++ b/src/common/dynamic_library.h
@@ -20,6 +20,9 @@ public:
     /// Automatically loads the specified library. Call IsOpen() to check validity before use.
     explicit DynamicLibrary(const char* filename);
 
+    /// Initializes the dynamic library with an already opened handle.
+    explicit DynamicLibrary(void* handle_);
+
     /// Moves the library.
     DynamicLibrary(DynamicLibrary&&) noexcept;
     DynamicLibrary& operator=(DynamicLibrary&&) noexcept;
diff --git a/src/common/error.cpp b/src/common/error.cpp
index ddb03bd45..1b2009db7 100644
--- a/src/common/error.cpp
+++ b/src/common/error.cpp
@@ -30,7 +30,8 @@ std::string NativeErrorToString(int e) {
     return ret;
 #else
     char err_str[255];
-#if defined(__GLIBC__) && (_GNU_SOURCE || (_POSIX_C_SOURCE < 200112L && _XOPEN_SOURCE < 600))
+#if defined(ANDROID) ||                                                                            \
+    (defined(__GLIBC__) && (_GNU_SOURCE || (_POSIX_C_SOURCE < 200112L && _XOPEN_SOURCE < 600)))
     // Thread safe (GNU-specific)
     const char* str = strerror_r(e, err_str, sizeof(err_str));
     return std::string(str);
diff --git a/src/common/fs/file.cpp b/src/common/fs/file.cpp
index 656b03cc5..b0b25eb43 100644
--- a/src/common/fs/file.cpp
+++ b/src/common/fs/file.cpp
@@ -5,6 +5,9 @@
 
 #include "common/fs/file.h"
 #include "common/fs/fs.h"
+#ifdef ANDROID
+#include "common/fs/fs_android.h"
+#endif
 #include "common/logging/log.h"
 
 #ifdef _WIN32
@@ -252,6 +255,23 @@ void IOFile::Open(const fs::path& path, FileAccessMode mode, FileType type, File
     } else {
         _wfopen_s(&file, path.c_str(), AccessModeToWStr(mode, type));
     }
+#elif ANDROID
+    if (Android::IsContentUri(path)) {
+        ASSERT_MSG(mode == FileAccessMode::Read, "Content URI file access is for read-only!");
+        const auto fd = Android::OpenContentUri(path, Android::OpenMode::Read);
+        if (fd != -1) {
+            file = fdopen(fd, "r");
+            const auto error_num = errno;
+            if (error_num != 0 && file == nullptr) {
+                LOG_ERROR(Common_Filesystem, "Error opening file: {}, error: {}", path.c_str(),
+                          strerror(error_num));
+            }
+        } else {
+            LOG_ERROR(Common_Filesystem, "Error opening file: {}", path.c_str());
+        }
+    } else {
+        file = std::fopen(path.c_str(), AccessModeToStr(mode, type));
+    }
 #else
     file = std::fopen(path.c_str(), AccessModeToStr(mode, type));
 #endif
@@ -372,6 +392,23 @@ u64 IOFile::GetSize() const {
     // Flush any unwritten buffered data into the file prior to retrieving the file size.
     std::fflush(file);
 
+#if ANDROID
+    u64 file_size = 0;
+    if (Android::IsContentUri(file_path)) {
+        file_size = Android::GetSize(file_path);
+    } else {
+        std::error_code ec;
+
+        file_size = fs::file_size(file_path, ec);
+
+        if (ec) {
+            LOG_ERROR(Common_Filesystem,
+                      "Failed to retrieve the file size of path={}, ec_message={}",
+                      PathToUTF8String(file_path), ec.message());
+            return 0;
+        }
+    }
+#else
     std::error_code ec;
 
     const auto file_size = fs::file_size(file_path, ec);
@@ -381,6 +418,7 @@ u64 IOFile::GetSize() const {
                   PathToUTF8String(file_path), ec.message());
         return 0;
     }
+#endif
 
     return file_size;
 }
diff --git a/src/common/fs/fs_android.cpp b/src/common/fs/fs_android.cpp
new file mode 100644
index 000000000..298a79bac
--- /dev/null
+++ b/src/common/fs/fs_android.cpp
@@ -0,0 +1,98 @@
+// SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "common/fs/fs_android.h"
+
+namespace Common::FS::Android {
+
+JNIEnv* GetEnvForThread() {
+    thread_local static struct OwnedEnv {
+        OwnedEnv() {
+            status = g_jvm->GetEnv(reinterpret_cast<void**>(&env), JNI_VERSION_1_6);
+            if (status == JNI_EDETACHED)
+                g_jvm->AttachCurrentThread(&env, nullptr);
+        }
+
+        ~OwnedEnv() {
+            if (status == JNI_EDETACHED)
+                g_jvm->DetachCurrentThread();
+        }
+
+        int status;
+        JNIEnv* env = nullptr;
+    } owned;
+    return owned.env;
+}
+
+void RegisterCallbacks(JNIEnv* env, jclass clazz) {
+    env->GetJavaVM(&g_jvm);
+    native_library = clazz;
+
+#define FR(FunctionName, ReturnValue, JMethodID, Caller, JMethodName, Signature)                   \
+    F(JMethodID, JMethodName, Signature)
+#define FS(FunctionName, ReturnValue, Parameters, JMethodID, JMethodName, Signature)               \
+    F(JMethodID, JMethodName, Signature)
+#define F(JMethodID, JMethodName, Signature)                                                       \
+    JMethodID = env->GetStaticMethodID(native_library, JMethodName, Signature);
+    ANDROID_SINGLE_PATH_DETERMINE_FUNCTIONS(FR)
+    ANDROID_STORAGE_FUNCTIONS(FS)
+#undef F
+#undef FS
+#undef FR
+}
+
+void UnRegisterCallbacks() {
+#define FR(FunctionName, ReturnValue, JMethodID, Caller, JMethodName, Signature) F(JMethodID)
+#define FS(FunctionName, ReturnValue, Parameters, JMethodID, JMethodName, Signature) F(JMethodID)
+#define F(JMethodID) JMethodID = nullptr;
+    ANDROID_SINGLE_PATH_DETERMINE_FUNCTIONS(FR)
+    ANDROID_STORAGE_FUNCTIONS(FS)
+#undef F
+#undef FS
+#undef FR
+}
+
+bool IsContentUri(const std::string& path) {
+    constexpr std::string_view prefix = "content://";
+    if (path.size() < prefix.size()) [[unlikely]] {
+        return false;
+    }
+
+    return path.find(prefix) == 0;
+}
+
+int OpenContentUri(const std::string& filepath, OpenMode openmode) {
+    if (open_content_uri == nullptr)
+        return -1;
+
+    const char* mode = "";
+    switch (openmode) {
+    case OpenMode::Read:
+        mode = "r";
+        break;
+    default:
+        UNIMPLEMENTED();
+        return -1;
+    }
+    auto env = GetEnvForThread();
+    jstring j_filepath = env->NewStringUTF(filepath.c_str());
+    jstring j_mode = env->NewStringUTF(mode);
+    return env->CallStaticIntMethod(native_library, open_content_uri, j_filepath, j_mode);
+}
+
+#define FR(FunctionName, ReturnValue, JMethodID, Caller, JMethodName, Signature)                   \
+    F(FunctionName, ReturnValue, JMethodID, Caller)
+#define F(FunctionName, ReturnValue, JMethodID, Caller)                                            \
+    ReturnValue FunctionName(const std::string& filepath) {                                        \
+        if (JMethodID == nullptr) {                                                                \
+            return 0;                                                                              \
+        }                                                                                          \
+        auto env = GetEnvForThread();                                                              \
+        jstring j_filepath = env->NewStringUTF(filepath.c_str());                                  \
+        return env->Caller(native_library, JMethodID, j_filepath);                                 \
+    }
+ANDROID_SINGLE_PATH_DETERMINE_FUNCTIONS(FR)
+#undef F
+#undef FR
+
+} // namespace Common::FS::Android
diff --git a/src/common/fs/fs_android.h b/src/common/fs/fs_android.h
new file mode 100644
index 000000000..bb8a52648
--- /dev/null
+++ b/src/common/fs/fs_android.h
@@ -0,0 +1,62 @@
+// SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <string>
+#include <vector>
+#include <jni.h>
+
+#define ANDROID_STORAGE_FUNCTIONS(V)                                                               \
+    V(OpenContentUri, int, (const std::string& filepath, OpenMode openmode), open_content_uri,     \
+      "openContentUri", "(Ljava/lang/String;Ljava/lang/String;)I")
+
+#define ANDROID_SINGLE_PATH_DETERMINE_FUNCTIONS(V)                                                 \
+    V(GetSize, std::uint64_t, get_size, CallStaticLongMethod, "getSize", "(Ljava/lang/String;)J")
+
+namespace Common::FS::Android {
+
+static JavaVM* g_jvm = nullptr;
+static jclass native_library = nullptr;
+
+#define FR(FunctionName, ReturnValue, JMethodID, Caller, JMethodName, Signature) F(JMethodID)
+#define FS(FunctionName, ReturnValue, Parameters, JMethodID, JMethodName, Signature) F(JMethodID)
+#define F(JMethodID) static jmethodID JMethodID = nullptr;
+ANDROID_SINGLE_PATH_DETERMINE_FUNCTIONS(FR)
+ANDROID_STORAGE_FUNCTIONS(FS)
+#undef F
+#undef FS
+#undef FR
+
+enum class OpenMode {
+    Read,
+    Write,
+    ReadWrite,
+    WriteAppend,
+    WriteTruncate,
+    ReadWriteAppend,
+    ReadWriteTruncate,
+    Never
+};
+
+void RegisterCallbacks(JNIEnv* env, jclass clazz);
+
+void UnRegisterCallbacks();
+
+bool IsContentUri(const std::string& path);
+
+#define FS(FunctionName, ReturnValue, Parameters, JMethodID, JMethodName, Signature)               \
+    F(FunctionName, Parameters, ReturnValue)
+#define F(FunctionName, Parameters, ReturnValue) ReturnValue FunctionName Parameters;
+ANDROID_STORAGE_FUNCTIONS(FS)
+#undef F
+#undef FS
+
+#define FR(FunctionName, ReturnValue, JMethodID, Caller, JMethodName, Signature)                   \
+    F(FunctionName, ReturnValue)
+#define F(FunctionName, ReturnValue) ReturnValue FunctionName(const std::string& filepath);
+ANDROID_SINGLE_PATH_DETERMINE_FUNCTIONS(FR)
+#undef F
+#undef FR
+
+} // namespace Common::FS::Android
diff --git a/src/common/fs/path_util.cpp b/src/common/fs/path_util.cpp
index defa3e918..e026a13d9 100644
--- a/src/common/fs/path_util.cpp
+++ b/src/common/fs/path_util.cpp
@@ -6,6 +6,9 @@
 #include <unordered_map>
 
 #include "common/fs/fs.h"
+#ifdef ANDROID
+#include "common/fs/fs_android.h"
+#endif
 #include "common/fs/fs_paths.h"
 #include "common/fs/path_util.h"
 #include "common/logging/log.h"
@@ -80,9 +83,7 @@ public:
         yuzu_paths.insert_or_assign(yuzu_path, new_path);
     }
 
-private:
-    PathManagerImpl() {
-        fs::path yuzu_path;
+    void Reinitialize(fs::path yuzu_path = {}) {
         fs::path yuzu_path_cache;
         fs::path yuzu_path_config;
 
@@ -95,6 +96,10 @@ private:
 
         yuzu_path_cache = yuzu_path / CACHE_DIR;
         yuzu_path_config = yuzu_path / CONFIG_DIR;
+#elif ANDROID
+        ASSERT(!yuzu_path.empty());
+        yuzu_path_cache = yuzu_path / CACHE_DIR;
+        yuzu_path_config = yuzu_path / CONFIG_DIR;
 #else
         yuzu_path = GetCurrentDir() / PORTABLE_DIR;
 
@@ -122,6 +127,11 @@ private:
         GenerateYuzuPath(YuzuPath::TASDir, yuzu_path / TAS_DIR);
     }
 
+private:
+    PathManagerImpl() {
+        Reinitialize();
+    }
+
     ~PathManagerImpl() = default;
 
     void GenerateYuzuPath(YuzuPath yuzu_path, const fs::path& new_path) {
@@ -210,6 +220,10 @@ fs::path RemoveTrailingSeparators(const fs::path& path) {
     return fs::path{string_path};
 }
 
+void SetAppDirectory(const std::string& app_directory) {
+    PathManagerImpl::GetInstance().Reinitialize(app_directory);
+}
+
 const fs::path& GetYuzuPath(YuzuPath yuzu_path) {
     return PathManagerImpl::GetInstance().GetYuzuPathImpl(yuzu_path);
 }
@@ -350,6 +364,12 @@ std::vector<std::string> SplitPathComponents(std::string_view filename) {
 
 std::string SanitizePath(std::string_view path_, DirectorySeparator directory_separator) {
     std::string path(path_);
+#ifdef ANDROID
+    if (Android::IsContentUri(path)) {
+        return path;
+    }
+#endif // ANDROID
+
     char type1 = directory_separator == DirectorySeparator::BackwardSlash ? '/' : '\\';
     char type2 = directory_separator == DirectorySeparator::BackwardSlash ? '\\' : '/';
 
diff --git a/src/common/fs/path_util.h b/src/common/fs/path_util.h
index 13d713f1e..7cfe85b70 100644
--- a/src/common/fs/path_util.h
+++ b/src/common/fs/path_util.h
@@ -181,6 +181,14 @@ template <typename Path>
 #endif
 
 /**
+ * Sets the directory used for application storage. Used on Android where we do not know internal
+ * storage until informed by the frontend.
+ *
+ * @param app_directory Directory to use for application storage.
+ */
+void SetAppDirectory(const std::string& app_directory);
+
+/**
  * Gets the filesystem path associated with the YuzuPath enum.
  *
  * @param yuzu_path YuzuPath enum
diff --git a/src/common/host_memory.cpp b/src/common/host_memory.cpp
index 8e4f1f97a..ba22595e0 100644
--- a/src/common/host_memory.cpp
+++ b/src/common/host_memory.cpp
@@ -11,9 +11,14 @@
 
 #elif defined(__linux__) || defined(__FreeBSD__) // ^^^ Windows ^^^ vvv Linux vvv
 
+#ifdef ANDROID
+#include <android/sharedmem.h>
+#endif
+
 #ifndef _GNU_SOURCE
 #define _GNU_SOURCE
 #endif
+#include <boost/icl/interval_set.hpp>
 #include <fcntl.h>
 #include <sys/mman.h>
 #include <unistd.h>
@@ -366,17 +371,20 @@ public:
         }
 
         // Backing memory initialization
-#if defined(__FreeBSD__) && __FreeBSD__ < 13
+#ifdef ANDROID
+        fd = ASharedMemory_create("HostMemory", backing_size);
+#elif defined(__FreeBSD__) && __FreeBSD__ < 13
         // XXX Drop after FreeBSD 12.* reaches EOL on 2024-06-30
         fd = shm_open(SHM_ANON, O_RDWR, 0600);
 #else
         fd = memfd_create("HostMemory", 0);
 #endif
-        if (fd == -1) {
+        if (fd < 0) {
             LOG_CRITICAL(HW_Memory, "memfd_create failed: {}", strerror(errno));
             throw std::bad_alloc{};
         }
 
+#ifndef ANDROID
         // Defined to extend the file with zeros
         int ret = ftruncate(fd, backing_size);
         if (ret != 0) {
@@ -384,6 +392,7 @@ public:
                          strerror(errno));
             throw std::bad_alloc{};
         }
+#endif
 
         backing_base = static_cast<u8*>(
             mmap(nullptr, backing_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0));
@@ -415,6 +424,7 @@ public:
         madvise(virtual_base, virtual_size, MADV_HUGEPAGE);
 #endif
 
+        placeholders.add({0, virtual_size});
         good = true;
     }
 
@@ -423,6 +433,10 @@ public:
     }
 
     void Map(size_t virtual_offset, size_t host_offset, size_t length) {
+        {
+            std::scoped_lock lock{placeholder_mutex};
+            placeholders.subtract({virtual_offset, virtual_offset + length});
+        }
 
         void* ret = mmap(virtual_base + virtual_offset, length, PROT_READ | PROT_WRITE,
                          MAP_SHARED | MAP_FIXED, fd, host_offset);
@@ -433,6 +447,19 @@ public:
         // The method name is wrong. We're still talking about the virtual range.
         // We don't want to unmap, we want to reserve this memory.
 
+        {
+            std::scoped_lock lock{placeholder_mutex};
+            auto it = placeholders.find({virtual_offset - 1, virtual_offset + length + 1});
+
+            if (it != placeholders.end()) {
+                size_t prev_upper = virtual_offset + length;
+                virtual_offset = std::min(virtual_offset, it->lower());
+                length = std::max(it->upper(), prev_upper) - virtual_offset;
+            }
+
+            placeholders.add({virtual_offset, virtual_offset + length});
+        }
+
         void* ret = mmap(virtual_base + virtual_offset, length, PROT_NONE,
                          MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
         ASSERT_MSG(ret != MAP_FAILED, "mmap failed: {}", strerror(errno));
@@ -476,6 +503,9 @@ private:
     }
 
     int fd{-1}; // memfd file descriptor, -1 is the error value of memfd_create
+
+    boost::icl::interval_set<size_t> placeholders; ///< Mapped placeholders
+    std::mutex placeholder_mutex;                  ///< Mutex for placeholders
 };
 
 #else // ^^^ Linux ^^^ vvv Generic vvv
diff --git a/src/common/logging/backend.cpp b/src/common/logging/backend.cpp
index f96c7c222..6e8e8eb36 100644
--- a/src/common/logging/backend.cpp
+++ b/src/common/logging/backend.cpp
@@ -155,6 +155,26 @@ public:
     void EnableForStacktrace() override {}
 };
 
+#ifdef ANDROID
+/**
+ * Backend that writes to the Android logcat
+ */
+class LogcatBackend : public Backend {
+public:
+    explicit LogcatBackend() = default;
+
+    ~LogcatBackend() override = default;
+
+    void Write(const Entry& entry) override {
+        PrintMessageToLogcat(entry);
+    }
+
+    void Flush() override {}
+
+    void EnableForStacktrace() override {}
+};
+#endif
+
 bool initialization_in_progress_suppress_logging = true;
 
 /**
@@ -260,6 +280,9 @@ private:
         lambda(static_cast<Backend&>(debugger_backend));
         lambda(static_cast<Backend&>(color_console_backend));
         lambda(static_cast<Backend&>(file_backend));
+#ifdef ANDROID
+        lambda(static_cast<Backend&>(lc_backend));
+#endif
     }
 
     static void Deleter(Impl* ptr) {
@@ -272,6 +295,9 @@ private:
     DebuggerBackend debugger_backend{};
     ColorConsoleBackend color_console_backend{};
     FileBackend file_backend;
+#ifdef ANDROID
+    LogcatBackend lc_backend{};
+#endif
 
     MPSCQueue<Entry> message_queue{};
     std::chrono::steady_clock::time_point time_origin{std::chrono::steady_clock::now()};
diff --git a/src/common/logging/text_formatter.cpp b/src/common/logging/text_formatter.cpp
index 09398ea64..2c453177b 100644
--- a/src/common/logging/text_formatter.cpp
+++ b/src/common/logging/text_formatter.cpp
@@ -8,6 +8,10 @@
 #include <windows.h>
 #endif
 
+#ifdef ANDROID
+#include <android/log.h>
+#endif
+
 #include "common/assert.h"
 #include "common/logging/filter.h"
 #include "common/logging/log.h"
@@ -106,4 +110,35 @@ void PrintColoredMessage(const Entry& entry) {
 #undef ESC
 #endif
 }
+
+void PrintMessageToLogcat(const Entry& entry) {
+#ifdef ANDROID
+    const auto str = FormatLogMessage(entry);
+
+    android_LogPriority android_log_priority;
+    switch (entry.log_level) {
+    case Level::Trace:
+        android_log_priority = ANDROID_LOG_VERBOSE;
+        break;
+    case Level::Debug:
+        android_log_priority = ANDROID_LOG_DEBUG;
+        break;
+    case Level::Info:
+        android_log_priority = ANDROID_LOG_INFO;
+        break;
+    case Level::Warning:
+        android_log_priority = ANDROID_LOG_WARN;
+        break;
+    case Level::Error:
+        android_log_priority = ANDROID_LOG_ERROR;
+        break;
+    case Level::Critical:
+        android_log_priority = ANDROID_LOG_FATAL;
+        break;
+    case Level::Count:
+        UNREACHABLE();
+    }
+    __android_log_print(android_log_priority, "YuzuNative", "%s", str.c_str());
+#endif
+}
 } // namespace Common::Log
diff --git a/src/common/logging/text_formatter.h b/src/common/logging/text_formatter.h
index 0d0ec4370..68417420b 100644
--- a/src/common/logging/text_formatter.h
+++ b/src/common/logging/text_formatter.h
@@ -15,4 +15,6 @@ std::string FormatLogMessage(const Entry& entry);
 void PrintMessage(const Entry& entry);
 /// Prints the same message as `PrintMessage`, but colored according to the severity level.
 void PrintColoredMessage(const Entry& entry);
+/// Formats and prints a log entry to the android logcat.
+void PrintMessageToLogcat(const Entry& entry);
 } // namespace Common::Log