Android: Prepare for the worst, when the NDK will remove all GNU tools

In NDKr18 Google removed GCC, most probably the massacre will not end
there and they will remove all GNU tools, so we need to start using LLVM
ones.

This patch still keeps the compatibility with GNU tools if the Qt was
built with android-g++ mkspec.

Change-Id: Ibe1979577e08ce63604d55fc5bbd5f64b3737675
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@qt.io>
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>

4 files changed, 78 insertions, 48 deletions

diff --git a/mkspecs/android-clang/qmake.conf b/mkspecs/android-clang/qmake.conf
index 1f5e690329..a0a369bb44 100644
--- a/mkspecs/android-clang/qmake.conf
+++ b/mkspecs/android-clang/qmake.conf
@@ -41,6 +41,8 @@ ANDROID_SOURCES_CXX_STL_LIBDIR = $$NDK_ROOT/sources/cxx-stl/llvm-libc++/libs/$$A
 
 ANDROID_STDCPP_PATH = $$ANDROID_SOURCES_CXX_STL_LIBDIR/libc++_shared.so
 
+ANDROID_USE_LLVM = true
+
 exists($$ANDROID_SOURCES_CXX_STL_LIBDIR/libc++.so): \
     ANDROID_CXX_STL_LIBS = -lc++
 else: \
diff --git a/mkspecs/android-g++/qmake.conf b/mkspecs/android-g++/qmake.conf
index e72c802405..0cb3558f96 100644
--- a/mkspecs/android-g++/qmake.conf
+++ b/mkspecs/android-g++/qmake.conf
@@ -16,6 +16,7 @@ QMAKE_LINK              = $$QMAKE_CXX
 ANDROID_SOURCES_CXX_STL_LIBDIR = $$NDK_ROOT/sources/cxx-stl/gnu-libstdc++/$$NDK_TOOLCHAIN_VERSION/libs/$$ANDROID_TARGET_ARCH
 ANDROID_STDCPP_PATH            = $$ANDROID_SOURCES_CXX_STL_LIBDIR/libgnustl_shared.so
 ANDROID_CXX_STL_LIBS           = -lgnustl_shared -lgcc
+ANDROID_USE_LLVM               = false
 
 exists($$NDK_ROOT/sysroot/usr/include): \
         QMAKE_CFLAGS += --sysroot=$$NDK_ROOT/sysroot \
diff --git a/mkspecs/features/android/android_deployment_settings.prf b/mkspecs/features/android/android_deployment_settings.prf
index e6b2431f9a..0db3230ce7 100644
--- a/mkspecs/features/android/android_deployment_settings.prf
+++ b/mkspecs/features/android/android_deployment_settings.prf
@@ -17,17 +17,22 @@ contains(TEMPLATE, ".*app"):!build_pass:!android-embedded {
     isEmpty(NDK_ROOT): NDK_ROOT = $$DEFAULT_ANDROID_NDK_ROOT
     FILE_CONTENT += "   \"ndk\": $$emitString($$NDK_ROOT),"
 
-    NDK_TOOLCHAIN_PREFIX = $$(ANDROID_NDK_TOOLCHAIN_PREFIX)
-    isEmpty(NDK_TOOLCHAIN_PREFIX) {
-        equals(ANDROID_TARGET_ARCH, x86): NDK_TOOLCHAIN_PREFIX = x86
-        else: equals(ANDROID_TARGET_ARCH, x86_64): NDK_TOOLCHAIN_PREFIX = x86_64
-        else: equals(ANDROID_TARGET_ARCH, mips): NDK_TOOLCHAIN_PREFIX = mipsel-linux-android
-        else: equals(ANDROID_TARGET_ARCH, mips64): NDK_TOOLCHAIN_PREFIX = mips64el-linux-android
-        else: equals(ANDROID_TARGET_ARCH, arm64-v8a): NDK_TOOLCHAIN_PREFIX = aarch64-linux-android
-        else: NDK_TOOLCHAIN_PREFIX = arm-linux-androideabi
+    equals(ANDROID_USE_LLVM, true) {
+        FILE_CONTENT += "   \"toolchain-prefix\": \"llvm\","
+        FILE_CONTENT += "   \"tool-prefix\": \"llvm\","
+    } else {
+        NDK_TOOLCHAIN_PREFIX = $$(ANDROID_NDK_TOOLCHAIN_PREFIX)
+        isEmpty(NDK_TOOLCHAIN_PREFIX) {
+            equals(ANDROID_TARGET_ARCH, x86): NDK_TOOLCHAIN_PREFIX = x86
+            else: equals(ANDROID_TARGET_ARCH, x86_64): NDK_TOOLCHAIN_PREFIX = x86_64
+            else: equals(ANDROID_TARGET_ARCH, mips): NDK_TOOLCHAIN_PREFIX = mipsel-linux-android
+            else: equals(ANDROID_TARGET_ARCH, mips64): NDK_TOOLCHAIN_PREFIX = mips64el-linux-android
+            else: equals(ANDROID_TARGET_ARCH, arm64-v8a): NDK_TOOLCHAIN_PREFIX = aarch64-linux-android
+            else: NDK_TOOLCHAIN_PREFIX = arm-linux-androideabi
+        }
+        FILE_CONTENT += "   \"toolchain-prefix\": $$emitString($$NDK_TOOLCHAIN_PREFIX),"
+        FILE_CONTENT += "   \"tool-prefix\": $$emitString($$NDK_TOOLS_PREFIX),"
     }
-    FILE_CONTENT += "   \"toolchain-prefix\": $$emitString($$NDK_TOOLCHAIN_PREFIX),"
-    FILE_CONTENT += "   \"tool-prefix\": $$emitString($$NDK_TOOLS_PREFIX),"
 
     NDK_TOOLCHAIN_VERSION = $$(ANDROID_NDK_TOOLCHAIN_VERSION)
     isEmpty(NDK_TOOLCHAIN_VERSION): NDK_TOOLCHAIN_VERSION = $$DEFAULT_ANDROID_NDK_TOOLCHAIN_VERSION
@@ -63,6 +68,7 @@ contains(TEMPLATE, ".*app"):!build_pass:!android-embedded {
         QML_ROOT_PATH = $$_PRO_FILE_PWD_
     FILE_CONTENT += "   \"qml-root-path\": $$emitString($$QML_ROOT_PATH),"
     FILE_CONTENT += "   \"stdcpp-path\": $$emitString($$ANDROID_STDCPP_PATH),"
+    FILE_CONTENT += "   \"useLLVM\": $$ANDROID_USE_LLVM,"
 
     FILE_CONTENT += "   \"application-binary\": $$emitString($$absolute_path($$DESTDIR, $$OUT_PWD)/$$TARGET)"
     FILE_CONTENT += "}"
diff --git a/src/tools/androiddeployqt/main.cpp b/src/tools/androiddeployqt/main.cpp
index 11213872f3..587ae21e4f 100644
--- a/src/tools/androiddeployqt/main.cpp
+++ b/src/tools/androiddeployqt/main.cpp
@@ -157,6 +157,7 @@ struct Options
     QString toolchainVersion;
     QString toolchainPrefix;
     QString toolPrefix;
+    bool useLLVM = false;
     QString ndkHost;
 
     // Package information
@@ -809,6 +810,11 @@ bool readInputFile(Options *options)
     }
 
     {
+        const QJsonValue value = jsonObject.value(QStringLiteral("useLLVM"));
+        options->useLLVM = value.toBool(false);
+    }
+
+    {
         const QJsonValue toolchainPrefix = jsonObject.value(QStringLiteral("toolchain-prefix"));
         if (toolchainPrefix.isUndefined()) {
             fprintf(stderr, "No toolchain prefix defined in json file.\n");
@@ -827,7 +833,7 @@ bool readInputFile(Options *options)
         }
     }
 
-    {
+    if (!options->useLLVM) {
         const QJsonValue toolchainVersion = jsonObject.value(QStringLiteral("toolchain-version"));
         if (toolchainVersion.isUndefined()) {
             fprintf(stderr, "No toolchain version defined in json file.\n");
@@ -863,15 +869,17 @@ bool readInputFile(Options *options)
 
     {
         const QJsonValue stdcppPath = jsonObject.value(QStringLiteral("stdcpp-path"));
-        if (!stdcppPath.isUndefined()) {
-            options->stdCppPath = stdcppPath.toString();
-            auto name = QFileInfo(options->stdCppPath).baseName();
-            if (!name.startsWith(QLatin1String("lib"))) {
-                fprintf(stderr, "Invalid STD C++ library name.\n");
-                return false;
-            }
-            options->stdCppName = name.mid(3);
+        if (stdcppPath.isUndefined()) {
+            fprintf(stderr, "No stdcpp-path defined in json file.\n");
+            return false;
+        }
+        options->stdCppPath = stdcppPath.toString();
+        auto name = QFileInfo(options->stdCppPath).baseName();
+        if (!name.startsWith(QLatin1String("lib"))) {
+            fprintf(stderr, "Invalid STD C++ library name.\n");
+            return false;
         }
+        options->stdCppName = name.mid(3);
     }
 
     {
@@ -1546,14 +1554,16 @@ QStringList getQtLibsFromElf(const Options &options, const QString &fileName)
 {
     QString readElf = options.ndkPath
             + QLatin1String("/toolchains/")
-            + options.toolchainPrefix
-            + QLatin1Char('-')
-            + options.toolchainVersion
-            + QLatin1String("/prebuilt/")
+            + options.toolchainPrefix;
+
+    if (!options.useLLVM)
+        readElf += QLatin1Char('-') + options.toolchainVersion;
+
+    readElf += QLatin1String("/prebuilt/")
             + options.ndkHost
             + QLatin1String("/bin/")
-            + options.toolPrefix
-            + QLatin1String("-readelf");
+            + options.toolPrefix +
+            (options.useLLVM ? QLatin1String("-readobj") : QLatin1String("-readelf"));
 #if defined(Q_OS_WIN32)
     readElf += QLatin1String(".exe");
 #endif
@@ -1563,27 +1573,40 @@ QStringList getQtLibsFromElf(const Options &options, const QString &fileName)
         return QStringList();
     }
 
-    readElf = QString::fromLatin1("%1 -d -W %2").arg(shellQuote(readElf)).arg(shellQuote(fileName));
+    if (options.useLLVM)
+        readElf = QString::fromLatin1("%1 -needed-libs %2").arg(shellQuote(readElf), shellQuote(fileName));
+    else
+        readElf = QString::fromLatin1("%1 -d -W %2").arg(shellQuote(readElf), shellQuote(fileName));
 
     FILE *readElfCommand = openProcess(readElf);
-    if (readElfCommand == 0) {
+    if (!readElfCommand) {
         fprintf(stderr, "Cannot execute command %s", qPrintable(readElf));
         return QStringList();
     }
 
     QStringList ret;
 
+    bool readLibs = false;
     char buffer[512];
     while (fgets(buffer, sizeof(buffer), readElfCommand) != 0) {
         QByteArray line = QByteArray::fromRawData(buffer, qstrlen(buffer));
-        if (line.contains("(NEEDED)") && line.contains("Shared library:") ) {
-            const int pos = line.lastIndexOf('[') + 1;
-            QString libraryName = QLatin1String("lib/") + QString::fromLatin1(line.mid(pos, line.length() - pos - 2));
-            if (QFile::exists(absoluteFilePath(&options, libraryName))) {
-                ret += libraryName;
+        QString library;
+        if (options.useLLVM) {
+            line = line.trimmed();
+            if (!readLibs) {
+                readLibs = line.startsWith("NeededLibraries");
+                continue;
             }
-
+            if (!line.startsWith("lib"))
+                continue;
+            library = QString::fromLatin1(line);
+        } else if (line.contains("(NEEDED)") && line.contains("Shared library:")) {
+            const int pos = line.lastIndexOf('[') + 1;
+            library = QString::fromLatin1(line.mid(pos, line.length() - pos - 2));
         }
+        QString libraryName = QLatin1String("lib/") + library;
+        if (QFile::exists(absoluteFilePath(&options, libraryName)))
+            ret += libraryName;
     }
 
     pclose(readElfCommand);
@@ -1837,10 +1860,12 @@ bool stripFile(const Options &options, const QString &fileName)
 {
     QString strip = options.ndkPath
             + QLatin1String("/toolchains/")
-            + options.toolchainPrefix
-            + QLatin1Char('-')
-            + options.toolchainVersion
-            + QLatin1String("/prebuilt/")
+            + options.toolchainPrefix;
+
+    if (!options.useLLVM)
+        strip += QLatin1Char('-') + options.toolchainVersion;
+
+    strip += QLatin1String("/prebuilt/")
             + options.ndkHost
             + QLatin1String("/bin/")
             + options.toolPrefix
@@ -1854,7 +1879,10 @@ bool stripFile(const Options &options, const QString &fileName)
         return false;
     }
 
-    strip = QString::fromLatin1("%1 %2").arg(shellQuote(strip)).arg(shellQuote(fileName));
+    if (options.useLLVM)
+        strip = QString::fromLatin1("%1 -strip-all -strip-all-gnu %2").arg(shellQuote(strip), shellQuote(fileName));
+    else
+        strip = QString::fromLatin1("%1 %2").arg(shellQuote(strip), shellQuote(fileName));
 
     FILE *stripCommand = openProcess(strip);
     if (stripCommand == 0) {
@@ -2423,22 +2451,15 @@ bool copyStdCpp(Options *options)
     if (options->verbose)
         fprintf(stdout, "Copying STL library\n");
 
-    QString filePath = !options->stdCppPath.isEmpty() ? options->stdCppPath
-                                                      : options->ndkPath
-            + QLatin1String("/sources/cxx-stl/gnu-libstdc++/")
-            + options->toolchainVersion
-            + QLatin1String("/libs/")
-            + options->architecture
-            + QLatin1String("/libgnustl_shared.so");
-    if (!QFile::exists(filePath)) {
-        fprintf(stderr, "STL library does not exist at %s\n", qPrintable(filePath));
+    if (!QFile::exists(options->stdCppPath)) {
+        fprintf(stderr, "STL library does not exist at %s\n", qPrintable(options->stdCppPath));
         return false;
     }
 
     const QString destinationDirectory = options->outputDirectory
             + QLatin1String("/libs/") + options->architecture;
 
-    if (!copyFileIfNewer(filePath, destinationDirectory + QLatin1String("/lib")
+    if (!copyFileIfNewer(options->stdCppPath, destinationDirectory + QLatin1String("/lib")
                                    + options->stdCppName + QLatin1String(".so"),
                          options->verbose)) {
         return false;