Add support for machine-readable JSON output to the MOC

The --output-json parameter will make moc produce a .json file next to the regular output file. With --collect-json the .json files for a module can be merged into a single one. Task-number: QTBUG-68796 Change-Id: I0e8fb802d47bd22da219701a8df947973d4bd7b5 Reviewed-by: Simon Hausmann <[email protected]> Reviewed-by: Ulf Hermann <[email protected]>
wx984490083 · Oct 4, 2019 · da284ef · da284ef
1 parent 64473c9
commit da284ef
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Showing 11 changed files with 3,144 additions and 6 deletions.
diff --git a/mkspecs/features/metatypes.prf b/mkspecs/features/metatypes.prf
@@ -0,0 +1,34 @@
+qtPrepareTool(MOC_COLLECT_JSON, moc)
+
+QMAKE_MOC_OPTIONS += --output-json
+
+moc_json_header.input = HEADERS
+moc_json_header.output = $$MOC_DIR/$${QMAKE_H_MOD_MOC}${QMAKE_FILE_BASE}$${first(QMAKE_EXT_CPP)}.json
+moc_json_header.CONFIG = no_link moc_verify
+moc_json_header.depends = $$MOC_DIR/$${QMAKE_H_MOD_MOC}${QMAKE_FILE_BASE}$${first(QMAKE_EXT_CPP)}
+moc_json_header.commands = $$escape_expand(\\n)  # force creation of rule
+moc_json_header.variable_out = MOC_JSON_FILES
+
+moc_json_source.input = SOURCES
+moc_json_source.output = $$MOC_DIR/$${QMAKE_CPP_MOD_MOC}${QMAKE_FILE_BASE}$${QMAKE_EXT_CPP_MOC}.json
+moc_json_source.CONFIG = no_link moc_verify
+moc_json_source.depends = $$MOC_DIR/$${QMAKE_CPP_MOD_MOC}${QMAKE_FILE_BASE}$${QMAKE_EXT_CPP_MOC}
+moc_json_source.commands = $$escape_expand(\\n)  # force creation of rule
+moc_json_source.variable_out = MOC_JSON_FILES
+
+MOC_COLLECT_JSON_OUTPUT = $$lower($$basename(TARGET))_metatypes.json
+
+moc_collect_json.CONFIG += no_link combine
+moc_collect_json.commands = $$MOC_COLLECT_JSON --collect-json -o ${QMAKE_FILE_OUT} ${QMAKE_FILE_IN}
+moc_collect_json.input = MOC_JSON_FILES
+moc_collect_json.output = $$MOC_COLLECT_JSON_OUTPUT
+moc_collect_json.name = Collect moc JSON output into central file
+
+install_metatypes {
+    do_install.path = $$[QT_INSTALL_LIBS]/metatypes
+    do_install.files = $$OUT_PWD/$$MOC_COLLECT_JSON_OUTPUT
+    prefix_build: INSTALLS += do_install
+    else: COPIES += do_install
+}
+
+QMAKE_EXTRA_COMPILERS += moc_collect_json moc_json_header moc_json_source
diff --git a/src/tools/moc/collectjson.cpp b/src/tools/moc/collectjson.cpp
@@ -0,0 +1,103 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the test suite 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.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <qfile.h>
+#include <qjsonarray.h>
+#include <qjsondocument.h>
+#include <qjsonobject.h>
+#include <qhashfunctions.h>
+#include <qstringlist.h>
+#include <cstdlib>
+
+static bool readFromDevice(QIODevice *device, QJsonArray *allMetaObjects)
+{
+    const QByteArray contents = device->readAll();
+    if (contents.isEmpty())
+        return true;
+
+    QJsonParseError error {};
+    QJsonDocument metaObjects = QJsonDocument::fromJson(contents, &error);
+    if (error.error != QJsonParseError::NoError) {
+        fprintf(stderr, "%s at %d\n", error.errorString().toUtf8().constData(), error.offset);
+        return false;
+    }
+
+    allMetaObjects->append(metaObjects.object());
+    return true;
+}
+
+int collectJson(const QStringList &jsonFiles, const QString &outputFile)
+{
+    qSetGlobalQHashSeed(0);
+
+    QFile output;
+    if (outputFile.isEmpty()) {
+        if (!output.open(stdout, QIODevice::WriteOnly)) {
+            fprintf(stderr, "Error opening stdout for writing\n");
+            return EXIT_FAILURE;
+        }
+    } else {
+        output.setFileName(outputFile);
+        if (!output.open(QIODevice::WriteOnly)) {
+            fprintf(stderr, "Error opening %s for writing\n", qPrintable(outputFile));
+            return EXIT_FAILURE;
+        }
+    }
+
+    QJsonArray allMetaObjects;
+    if (jsonFiles.isEmpty()) {
+        QFile f;
+        if (!f.open(stdin, QIODevice::ReadOnly)) {
+            fprintf(stderr, "Error opening stdin for reading\n");
+            return EXIT_FAILURE;
+        }
+
+        if (!readFromDevice(&f, &allMetaObjects)) {
+            fprintf(stderr, "Error parsing data from stdin\n");
+            return EXIT_FAILURE;
+        }
+    }
+
+    for (const QString &jsonFile: jsonFiles) {
+        QFile f(jsonFile);
+        if (!f.open(QIODevice::ReadOnly)) {
+            fprintf(stderr, "Error opening %s for reading\n", qPrintable(jsonFile));
+            return EXIT_FAILURE;
+        }
+
+        if (!readFromDevice(&f, &allMetaObjects)) {
+            fprintf(stderr, "Error parsing %s\n", qPrintable(jsonFile));
+            return EXIT_FAILURE;
+        }
+    }
+
+    QJsonDocument doc(allMetaObjects);
+    output.write(doc.toJson());
+
+    return EXIT_SUCCESS;
+}
diff --git a/src/tools/moc/collectjson.h b/src/tools/moc/collectjson.h
@@ -0,0 +1,42 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 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 COLLECTJSON_H
+#define COLLECTJSON_H
+
+#include <qglobal.h>
+#include <qstring.h>
+#include <qstringlist.h>
+
+QT_BEGIN_NAMESPACE
+
+int collectJson(const QStringList &jsonFiles, const QString &outputFile);
+
+QT_END_NAMESPACE
+
+#endif // COLLECTOJSON_H
diff --git a/src/tools/moc/main.cpp b/src/tools/moc/main.cpp
@@ -30,17 +30,20 @@
 #include "preprocessor.h"
 #include "moc.h"
 #include "outputrevision.h"
+#include "collectjson.h"
 
 #include <qfile.h>
 #include <qfileinfo.h>
 #include <qdir.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <ctype.h>
+#include <errno.h>
 
 #include <qcoreapplication.h>
 #include <qcommandlineoption.h>
 #include <qcommandlineparser.h>
+#include <qscopedpointer.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -77,6 +80,10 @@ void error(const char *msg = "Invalid argument")
         fprintf(stderr, "moc: %s\n", msg);
 }
 
+struct ScopedPointerFileCloser
+{
+    static inline void cleanup(FILE *handle) { if (handle) fclose(handle); }
+};
 
 static inline bool hasNext(const Symbols &symbols, int i)
 { return (i < symbols.size()); }
@@ -293,10 +300,20 @@ int runMoc(int argc, char **argv)
     ignoreConflictsOption.setDescription(QStringLiteral("Ignore all options that conflict with compilers, like -pthread conflicting with moc's -p option."));
     parser.addOption(ignoreConflictsOption);
 
+    QCommandLineOption jsonOption(QStringLiteral("output-json"));
+    jsonOption.setDescription(QStringLiteral("In addition to generating C++ code, create a machine-readable JSON file in a file that matches the output file and an extra .json extension."));
+    parser.addOption(jsonOption);
+
+    QCommandLineOption collectOption(QStringLiteral("collect-json"));
+    collectOption.setDescription(QStringLiteral("Instead of processing C++ code, collect previously generated JSON output into a single file."));
+    parser.addOption(collectOption);
+
     parser.addPositionalArgument(QStringLiteral("[header-file]"),
             QStringLiteral("Header file to read from, otherwise stdin."));
     parser.addPositionalArgument(QStringLiteral("[@option-file]"),
             QStringLiteral("Read additional options from option-file."));
+    parser.addPositionalArgument(QStringLiteral("[MOC generated json file]"),
+                                 QStringLiteral("MOC generated json output"));
 
     const QStringList arguments = argumentsFromCommandLineAndFile(app.arguments());
     if (arguments.isEmpty())
@@ -305,6 +322,10 @@ int runMoc(int argc, char **argv)
     parser.process(arguments);
 
     const QStringList files = parser.positionalArguments();
+    output = parser.value(outputOption);
+    if (parser.isSet(collectOption))
+        return collectJson(files, output);
+
     if (files.count() > 1) {
         error(qPrintable(QLatin1String("Too many input files specified: '") + files.join(QLatin1String("' '")) + QLatin1Char('\'')));
         parser.showHelp(1);
@@ -313,7 +334,6 @@ int runMoc(int argc, char **argv)
     }
 
     const bool ignoreConflictingOptions = parser.isSet(ignoreConflictsOption);
-    output = parser.value(outputOption);
     pp.preprocessOnly = parser.isSet(preprocessOption);
     if (parser.isSet(noIncludeOption)) {
         moc.noInclude = true;
@@ -485,6 +505,8 @@ int runMoc(int argc, char **argv)
 
     // 3. and output meta object code
 
+    QScopedPointer<FILE, ScopedPointerFileCloser> jsonOutput;
+
     if (output.size()) { // output file specified
 #if defined(_MSC_VER)
         if (_wfopen_s(&out, reinterpret_cast<const wchar_t *>(output.utf16()), L"w") != 0)
@@ -496,6 +518,21 @@ int runMoc(int argc, char **argv)
             fprintf(stderr, "moc: Cannot create %s\n", QFile::encodeName(output).constData());
             return 1;
         }
+
+        if (parser.isSet(jsonOption)) {
+            const QString jsonOutputFileName = output + QLatin1String(".json");
+            FILE *f;
+#if defined(_MSC_VER)
+            if (_wfopen_s(&f, reinterpret_cast<const wchar_t *>(jsonOutputFileName.utf16()), L"w") != 0)
+#else
+            f = fopen(QFile::encodeName(jsonOutputFileName).constData(), "w");
+            if (!f)
+#endif
+                fprintf(stderr, "moc: Cannot create JSON output file %s. %s\n",
+                        QFile::encodeName(jsonOutputFileName).constData(),
+                        strerror(errno));
+            jsonOutput.reset(f);
+        }
     } else { // use stdout
         out = stdout;
     }
@@ -506,7 +543,7 @@ int runMoc(int argc, char **argv)
         if (moc.classList.isEmpty())
             moc.note("No relevant classes found. No output generated.");
         else
-            moc.generate(out);
+            moc.generate(out, jsonOutput.data());
     }
 
     if (output.size())