Let androiddeployqt write a dependency file

Let androiddeployqt write a dependency file so that
the build system knows when to re-run it.

Fixes: QTBUG-94567
Change-Id: I5985d707f257b22789013a74f0a6f7c4de6e5e88
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>

6 files changed, 176 insertions, 65 deletions

diff --git a/src/corelib/Qt6AndroidMacros.cmake b/src/corelib/Qt6AndroidMacros.cmake
index b7d2490522..e37ce287bd 100644
--- a/src/corelib/Qt6AndroidMacros.cmake
+++ b/src/corelib/Qt6AndroidMacros.cmake
@@ -291,10 +291,13 @@ function(qt6_android_add_apk_target target)
     set(apk_final_dir "$<TARGET_PROPERTY:${target},BINARY_DIR>/android-build")
     set(apk_intermediate_dir "${CMAKE_CURRENT_BINARY_DIR}/android-build")
     set(apk_file_name "${target}.apk")
+    set(dep_file_name "${target}.d")
     set(apk_final_file_path "${apk_final_dir}/${apk_file_name}")
     set(apk_intermediate_file_path "${apk_intermediate_dir}/${apk_file_name}")
+    set(dep_intermediate_file_path "${apk_intermediate_dir}/${dep_file_name}")
 
-    # This target is used by Qt Creator's Android support.
+    # This target is used by Qt Creator's Android support and by the ${target}_make_apk target
+    # in case DEPFILEs are not supported.
     add_custom_target(${target}_prepare_apk_dir ALL
         DEPENDS ${target}
         COMMAND ${CMAKE_COMMAND}
@@ -303,26 +306,42 @@ function(qt6_android_add_apk_target target)
         COMMENT "Copying ${target} binary to apk folder"
     )
 
-    # Add custom command that creates the apk in an intermediate location.
-    # We need the intermediate location, because we cannot have target-dependent generator
-    # expressions in OUTPUT.
-    add_custom_command(OUTPUT "${apk_intermediate_file_path}"
-        COMMAND ${CMAKE_COMMAND}
-            -E copy "$<TARGET_FILE:${target}>"
-            "${apk_intermediate_dir}/libs/${CMAKE_ANDROID_ARCH_ABI}/$<TARGET_FILE_NAME:${target}>"
-        COMMAND "${deployment_tool}"
-            --input "${deployment_file}"
-            --output "${apk_intermediate_dir}"
-            --apk "${apk_intermediate_file_path}"
-        COMMENT "Creating APK for ${target}"
-        DEPENDS "${target}" "${deployment_file}")
-
-    # Create a ${target}_make_apk target to copy the apk from the intermediate to its final
-    # location.  If the final and intermediate locations are identical, this is a no-op.
-    add_custom_target(${target}_make_apk
-        COMMAND "${CMAKE_COMMAND}"
-            -E copy_if_different "${apk_intermediate_file_path}" "${apk_final_file_path}"
-        DEPENDS "${apk_intermediate_file_path}")
+    # The DEPFILE argument to add_custom_command is only available with Ninja or CMake>=3.20 and make.
+    if (CMAKE_GENERATOR MATCHES "Ninja" OR
+        (CMAKE_VERSION VERSION_GREATER_EQUAL 3.20 AND CMAKE_GENERATOR MATCHES "Makefiles"))
+        # Add custom command that creates the apk in an intermediate location.
+        # We need the intermediate location, because we cannot have target-dependent generator
+        # expressions in OUTPUT.
+        add_custom_command(OUTPUT "${apk_intermediate_file_path}"
+            COMMAND ${CMAKE_COMMAND}
+                -E copy "$<TARGET_FILE:${target}>"
+                "${apk_intermediate_dir}/libs/${CMAKE_ANDROID_ARCH_ABI}/$<TARGET_FILE_NAME:${target}>"
+            COMMAND "${deployment_tool}"
+                --input "${deployment_file}"
+                --output "${apk_intermediate_dir}"
+                --apk "${apk_intermediate_file_path}"
+                --depfile "${dep_intermediate_file_path}"
+                --builddir "${CMAKE_BINARY_DIR}"
+            COMMENT "Creating APK for ${target}"
+            DEPENDS "${target}" "${deployment_file}"
+            DEPFILE "${dep_intermediate_file_path}")
+
+        # Create a ${target}_make_apk target to copy the apk from the intermediate to its final
+        # location.  If the final and intermediate locations are identical, this is a no-op.
+        add_custom_target(${target}_make_apk
+            COMMAND "${CMAKE_COMMAND}"
+                -E copy_if_different "${apk_intermediate_file_path}" "${apk_final_file_path}"
+            DEPENDS "${apk_intermediate_file_path}")
+    else()
+        add_custom_target(${target}_make_apk
+            DEPENDS ${target}_prepare_apk_dir
+            COMMAND  ${deployment_tool}
+                --input ${deployment_file}
+                --output ${apk_final_dir}
+                --apk ${apk_final_file_path}
+            COMMENT "Creating APK for ${target}"
+        )
+    endif()
 endfunction()
 
 function(_qt_internal_create_global_apk_target)
diff --git a/src/tools/androiddeployqt/CMakeLists.txt b/src/tools/androiddeployqt/CMakeLists.txt
index 4eec7b8164..941e160318 100644
--- a/src/tools/androiddeployqt/CMakeLists.txt
+++ b/src/tools/androiddeployqt/CMakeLists.txt
@@ -13,6 +13,8 @@ qt_internal_add_app(androiddeployqt
         QT_NO_FOREACH
     PUBLIC_LIBRARIES
         Qt::Core # special case
+    INCLUDE_DIRECTORIES
+        ../shared
 )
 set_target_properties(androiddeployqt PROPERTIES
     WIN32_EXECUTABLE FALSE
diff --git a/src/tools/androiddeployqt/main.cpp b/src/tools/androiddeployqt/main.cpp
index 7993a0cfb8..fcfb6d36f5 100644
--- a/src/tools/androiddeployqt/main.cpp
+++ b/src/tools/androiddeployqt/main.cpp
@@ -42,6 +42,8 @@
 #include <QDirIterator>
 #include <QRegularExpression>
 
+#include <depfile_shared.h>
+
 #include <algorithm>
 
 #if defined(Q_OS_WIN32)
@@ -73,6 +75,8 @@ public:
 
 static const bool mustReadOutputAnyway = true; // pclose seems to return the wrong error code unless we read the output
 
+static QStringList dependenciesForDepfile;
+
 void deleteRecursively(const QString &dirName)
 {
     QDir dir(dirName);
@@ -169,6 +173,8 @@ struct Options
     QString applicationArguments;
     QString rootPath;
     QString rccBinaryPath;
+    QString depFilePath;
+    QString buildDirectory;
     QStringList qmlImportPaths;
     QStringList qrcFiles;
 
@@ -474,6 +480,16 @@ Options parseOptions()
                 options.helpRequested = true;
             else
                 options.apkPath = arguments.at(++i);
+        } else if (argument.compare(QLatin1String("--depfile"), Qt::CaseInsensitive) == 0) {
+            if (i + 1 == arguments.size())
+                options.helpRequested = true;
+            else
+                options.depFilePath = arguments.at(++i);
+        } else if (argument.compare(QLatin1String("--builddir"), Qt::CaseInsensitive) == 0) {
+            if (i + 1 == arguments.size())
+                options.helpRequested = true;
+            else
+                options.buildDirectory = arguments.at(++i);
         } else if (argument.compare(QLatin1String("--sign"), Qt::CaseInsensitive) == 0) {
             if (i + 2 >= arguments.size()) {
                 const QString keyStore = qEnvironmentVariable("QT_ANDROID_KEYSTORE_PATH");
@@ -560,6 +576,9 @@ Options parseOptions()
         }
     }
 
+    if (options.buildDirectory.isEmpty() && !options.depFilePath.isEmpty())
+        options.helpRequested = true;
+
     if (options.inputFileName.isEmpty())
         options.inputFileName = QLatin1String("android-%1-deployment-settings.json").arg(QDir::current().dirName());
 
@@ -668,6 +687,11 @@ void printHelp()
                     "       qmlimportscanner binary is located using the Qt directory\n"
                     "       specified in the input file.\n"
                     "\n"
+                    "   --depfile <path/to/depfile>: Output a dependency file.\n"
+                    "\n"
+                    "   --builddir <path/to/build/directory>: build directory. Necessary when\n"
+                    "       generating a depfile because ninja requires relative paths.\n"
+                    "\n"
                     "    --help: Displays this information.\n",
                     qPrintable(QCoreApplication::arguments().at(0))
             );
@@ -703,6 +727,7 @@ bool copyFileIfNewer(const QString &sourceFileName,
                      const Options &options,
                      bool forceOverwrite = false)
 {
+    dependenciesForDepfile << sourceFileName;
     if (QFile::exists(destinationFileName)) {
         QFileInfo destinationFileInfo(destinationFileName);
         QFileInfo sourceFileInfo(sourceFileName);
@@ -840,6 +865,7 @@ bool readInputFile(Options *options)
         fprintf(stderr, "Cannot read from input file: %s\n", qPrintable(options->inputFileName));
         return false;
     }
+    dependenciesForDepfile << options->inputFileName;
 
     QJsonDocument jsonDocument = QJsonDocument::fromJson(file.readAll());
     if (jsonDocument.isNull()) {
@@ -2950,6 +2976,29 @@ enum ErrorCode
     CannotCreateRcc = 21
 };
 
+bool writeDependencyFile(const Options &options)
+{
+    if (options.verbose)
+        fprintf(stdout, "Writing dependency file.\n");
+
+    QFile depFile(options.depFilePath);
+
+    QString relativeApkPath = QDir(options.buildDirectory).relativeFilePath(options.apkPath);
+
+    if (depFile.open(QIODevice::WriteOnly)) {
+        depFile.write(escapeAndEncodeDependencyPath(relativeApkPath));
+        depFile.write(u8": ");
+
+        for (const auto &file : dependenciesForDepfile) {
+            depFile.write(u8" \\\n    ");
+            depFile.write(escapeAndEncodeDependencyPath(file));
+        }
+
+        depFile.write(u8"\n");
+    }
+    return true;
+}
+
 int main(int argc, char *argv[])
 {
     QCoreApplication a(argc, argv);
@@ -3090,6 +3139,9 @@ int main(int argc, char *argv[])
     if (Q_UNLIKELY(options.timing))
         fprintf(stdout, "[TIMING] %d ms: Installed APK\n", options.timer.elapsed());
 
+    if (!options.depFilePath.isEmpty())
+        writeDependencyFile(options);
+
     fprintf(stdout, "Android package built successfully in %.3f ms.\n", options.timer.elapsed() / 1000.);
 
     if (options.installApk)
diff --git a/src/tools/moc/CMakeLists.txt b/src/tools/moc/CMakeLists.txt
index 09c4927a53..88dce045f8 100644
--- a/src/tools/moc/CMakeLists.txt
+++ b/src/tools/moc/CMakeLists.txt
@@ -32,6 +32,7 @@ qt_internal_add_tool(${target_name}
     INCLUDE_DIRECTORIES
         ${CMAKE_CURRENT_SOURCE_DIR}
         ../../3rdparty/tinycbor/src
+        ../shared
 )
 
 #### Keys ignored in scope 1:.:.:moc.pro:<TRUE>:
diff --git a/src/tools/moc/main.cpp b/src/tools/moc/main.cpp
index a2790fa1f7..3e98fbf2b8 100644
--- a/src/tools/moc/main.cpp
+++ b/src/tools/moc/main.cpp
@@ -27,6 +27,7 @@
 **
 ****************************************************************************/
 
+#include <depfile_shared.h>
 #include "preprocessor.h"
 #include "moc.h"
 #include "outputrevision.h"
@@ -177,50 +178,6 @@ static QStringList argumentsFromCommandLineAndFile(const QStringList &arguments,
     return allArguments;
 }
 
-// Escape characters in given path. Dependency paths are Make-style, not NMake/Jom style.
-// The paths can also be consumed by Ninja.
-// "$" replaced by "$$"
-// "#" replaced by "\#"
-// " " replaced by "\ "
-// "\#" replaced by "\\#"
-// "\ " replaced by "\\\ "
-//
-// The escape rules are according to what clang / llvm escapes when generating a Make-style
-// dependency file.
-// Is a template function, because input param can be either a QString or a QByteArray.
-template <typename T> struct CharType;
-template <> struct CharType<QString> { using type = QLatin1Char; };
-template <> struct CharType<QByteArray> { using type = char; };
-template <typename StringType>
-StringType escapeDependencyPath(const StringType &path)
-{
-    using CT = typename CharType<StringType>::type;
-    StringType escapedPath;
-    int size = path.size();
-    escapedPath.reserve(size);
-    for (int i = 0; i < size; ++i) {
-        if (path[i] == CT('$')) {
-            escapedPath.append(CT('$'));
-        } else if (path[i] == CT('#')) {
-            escapedPath.append(CT('\\'));
-        } else if (path[i] == CT(' ')) {
-            escapedPath.append(CT('\\'));
-            int backwards_it = i - 1;
-            while (backwards_it > 0 && path[backwards_it] == CT('\\')) {
-                escapedPath.append(CT('\\'));
-                --backwards_it;
-            }
-        }
-        escapedPath.append(path[i]);
-    }
-    return escapedPath;
-}
-
-QByteArray escapeAndEncodeDependencyPath(const QString &path)
-{
-    return QFile::encodeName(escapeDependencyPath(path));
-}
-
 int runMoc(int argc, char **argv)
 {
     QCoreApplication app(argc, argv);
diff --git a/src/tools/shared/depfile_shared.h b/src/tools/shared/depfile_shared.h
new file mode 100644
index 0000000000..9fb9bbb863
--- /dev/null
+++ b/src/tools/shared/depfile_shared.h
@@ -0,0 +1,80 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the tools applications of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:GPL-EXCEPT$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QTBASE_DEPFILE_SHARED_H
+#define QTBASE_DEPFILE_SHARED_H
+
+#include <QByteArray>
+#include <QString>
+#include <QFile>
+
+// Escape characters in given path. Dependency paths are Make-style, not NMake/Jom style.
+// The paths can also be consumed by Ninja.
+// "$" replaced by "$$"
+// "#" replaced by "\#"
+// " " replaced by "\ "
+// "\#" replaced by "\\#"
+// "\ " replaced by "\\\ "
+//
+// The escape rules are according to what clang / llvm escapes when generating a Make-style
+// dependency file.
+// Is a template function, because input param can be either a QString or a QByteArray.
+template <typename T> struct CharType;
+template <> struct CharType<QString> { using type = QLatin1Char; };
+template <> struct CharType<QByteArray> { using type = char; };
+template <typename StringType>
+StringType escapeDependencyPath(const StringType &path)
+{
+    using CT = typename CharType<StringType>::type;
+    StringType escapedPath;
+    int size = path.size();
+    escapedPath.reserve(size);
+    for (int i = 0; i < size; ++i) {
+        if (path[i] == CT('$')) {
+            escapedPath.append(CT('$'));
+        } else if (path[i] == CT('#')) {
+            escapedPath.append(CT('\\'));
+        } else if (path[i] == CT(' ')) {
+            escapedPath.append(CT('\\'));
+            int backwards_it = i - 1;
+            while (backwards_it > 0 && path[backwards_it] == CT('\\')) {
+                escapedPath.append(CT('\\'));
+                --backwards_it;
+            }
+        }
+        escapedPath.append(path[i]);
+    }
+    return escapedPath;
+}
+
+static inline QByteArray escapeAndEncodeDependencyPath(const QString &path)
+{
+    return QFile::encodeName(escapeDependencyPath(path));
+}
+
+#endif // QTBASE_DEPFILE_SHARED_H