Add a Mach-O decoder to the QPluginLoader

We already had an ELF decoder, which helped us greatly to find the
metadata and that catches most Unix systems (Solaris, QNX, HP-UXi, and
all of the free Unixes). On other Unix systems, aside from Mac OS X,
we simply scanned the entire file for the signature. On Windows, even
without a COFF-PE decoder, we use a LoadLibrary trick to load the
plugin without loading the dependent libraries. In most cases, that
works.

Unfortunately, on Mac OS X we didn't have a decoder and nor could we
do the file scan: because Mac OS X binaries could be fat binaries, we
wouldn't know which architecture's signature we had found.

No more. This adds a full Mach-O decoder to QtCore. It is also capable
of finding the boundaries of the architecture's binary, but that
functionality is disabled since all Qt 5 plugins have plugin metadata
sections.

Change-Id: I2d5c04c5ecf024864b8a43f31ab6b7e6c5eae9ce
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

6 files changed, 289 insertions, 2 deletions

diff --git a/tests/auto/corelib/plugin/qpluginloader/fakeplugin.cpp b/tests/auto/corelib/plugin/qpluginloader/fakeplugin.cpp
new file mode 100644
index 0000000000..d5c933e3af
--- /dev/null
+++ b/tests/auto/corelib/plugin/qpluginloader/fakeplugin.cpp
@@ -0,0 +1,49 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Intel Corporation
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** 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 Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtCore/qplugin.h>
+
+#if QT_POINTER_SIZE == 8
+QT_PLUGIN_METADATA_SECTION void *const pluginSection = (void*)(0xc0ffeec0ffeeL);
+#else
+QT_PLUGIN_METADATA_SECTION void *const pluginSection = (void*)0xc0ffee;
+#endif
+QT_PLUGIN_METADATA_SECTION const char message[] = "QTMETADATA";
diff --git a/tests/auto/corelib/plugin/qpluginloader/machtest/machtest.pro b/tests/auto/corelib/plugin/qpluginloader/machtest/machtest.pro
new file mode 100644
index 0000000000..d4fc9f2836
--- /dev/null
+++ b/tests/auto/corelib/plugin/qpluginloader/machtest/machtest.pro
@@ -0,0 +1,51 @@
+TEMPLATE = aux
+OTHER_FILES += \
+    ppcconverter.pl
+
+i386.target = good.i386.dylib
+i386.commands = $(CXX) -shared -arch i386 -o $@ -I$$[QT_INSTALL_HEADERS/get] $<
+i386.depends += $$PWD/../fakeplugin.cpp
+x86_64.target = good.x86_64.dylib
+x86_64.commands = $(CXX) -shared -arch x86_64 -o $@ -I$$[QT_INSTALL_HEADERS/get] $<
+x86_64.depends += $$PWD/../fakeplugin.cpp
+
+# Current Mac OS X toolchains have no compiler for PPC anymore
+# So we fake it by converting an x86-64 binary to (little-endian!) PPC64
+ppc64.target = good.ppc64.dylib
+ppc64.commands = $$PWD/ppcconverter.pl $< $@
+ppc64.depends = x86_64 $$PWD/ppcconverter.pl
+
+# Generate a fat binary with three architectures
+fat_all.target = good.fat.all.dylib
+fat_all.commands = lipo -create -output $@ \
+                              -arch ppc64 $$ppc64.target \
+                              -arch i386 $$i386.target \
+                              -arch x86_64 $$x86_64.target
+fat_all.depends += i386 x86_64 ppc64
+
+fat_no_i386.target = good.fat.no-i386.dylib
+fat_no_i386.commands = lipo -create -output $@ -arch x86_64 $$x86_64.target -arch ppc64 $$ppc64.target
+fat_no_i386.depends += x86_64 ppc64
+
+fat_no_x86_64.target = good.fat.no-x86_64.dylib
+fat_no_x86_64.commands = lipo -create -output $@ -arch i386 $$i386.target -arch ppc64 $$ppc64.target
+fat_no_x86_64.depends += i386 ppc64
+
+fat_stub_i386.target = good.fat.stub-i386.dylib
+fat_stub_i386.commands = lipo -create -output $@ -arch ppc64 $$ppc64.target -arch_blank i386
+fat_stub_i386.depends += x86_64 ppc64
+
+fat_stub_x86_64.target = good.fat.stub-x86_64.dylib
+fat_stub_x86_64.commands = lipo -create -output $@ -arch ppc64 $$ppc64.target -arch_blank x86_64
+fat_stub_x86_64.depends += i386 ppc64
+
+MYTARGETS = $$fat_all.depends fat_all fat_no_x86_64 fat_no_i386 \
+            fat_stub_i386 fat_stub_x86_64
+all.depends += $$MYTARGETS
+QMAKE_EXTRA_TARGETS += $$MYTARGETS all
+
+QMAKE_CLEAN += $$i386.target $$x86_64.target $$ppc64.target $$fat_all.target \
+            $$fat_no_i386.target $$fat_no_x86_64.target \
+            $$fat_stub_i386.target $$fat_stub_x86_64.target
+
+
diff --git a/tests/auto/corelib/plugin/qpluginloader/machtest/ppcconverter.pl b/tests/auto/corelib/plugin/qpluginloader/machtest/ppcconverter.pl
new file mode 100755
index 0000000000..86943161b7
--- /dev/null
+++ b/tests/auto/corelib/plugin/qpluginloader/machtest/ppcconverter.pl
@@ -0,0 +1,112 @@
+#!/usr/bin/perl
+#############################################################################
+##
+## Copyright (C) 2013 Intel Corporation.
+## Contact: http://www.qt-project.org/legal
+##
+## This file is the build configuration utility of the Qt Toolkit.
+##
+## $QT_BEGIN_LICENSE:LGPL$
+## 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 Digia.  For licensing terms and
+## conditions see http://qt.digia.com/licensing.  For further information
+## use the contact form at http://qt.digia.com/contact-us.
+##
+## GNU Lesser General Public License Usage
+## Alternatively, this file may be used under the terms of the GNU Lesser
+## General Public License version 2.1 as published by the Free Software
+## Foundation and appearing in the file LICENSE.LGPL included in the
+## packaging of this file.  Please review the following information to
+## ensure the GNU Lesser General Public License version 2.1 requirements
+## will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+##
+## In addition, as a special exception, Digia gives you certain additional
+## rights.  These rights are described in the Digia Qt LGPL Exception
+## version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+##
+## GNU General Public License Usage
+## Alternatively, this file may be used under the terms of the GNU
+## General Public License version 3.0 as published by the Free Software
+## Foundation and appearing in the file LICENSE.GPL included in the
+## packaging of this file.  Please review the following information to
+## ensure the GNU General Public License version 3.0 requirements will be
+## met: http://www.gnu.org/copyleft/gpl.html.
+##
+##
+## $QT_END_LICENSE$
+##
+#############################################################################
+
+# Changes the Mach-O file type header to PowerPC.
+#
+# The header is (from mach-o/loader.h):
+# struct mach_header {
+#    uint32_t   magic;          /* mach magic number identifier */
+#    cpu_type_t cputype;        /* cpu specifier */
+#    cpu_subtype_t      cpusubtype;     /* machine specifier */
+#    uint32_t   filetype;       /* type of file */
+#    uint32_t   ncmds;          /* number of load commands */
+#    uint32_t   sizeofcmds;     /* the size of all the load commands */
+#    uint32_t   flags;          /* flags */
+# };
+#
+# The 64-bit header is identical in the first three fields, except for a different
+# magic number. We will not touch the magic number, we'll just reset the cputype
+# field to the PowerPC type and the subtype field to zero.
+#
+# We will not change the file's endianness. That means we might create a little-endian
+# PowerPC binary, which could not be run in real life.
+#
+# We will also not change the 64-bit ABI flag, which is found in the cputype's high
+# byte. That means we'll create a PPC64 binary if fed a 64-bit input.
+#
+use strict;
+use constant MH_MAGIC => 0xfeedface;
+use constant MH_CIGAM => 0xcefaedfe;
+use constant MH_MAGIC_64 => 0xfeedfacf;
+use constant MH_CIGAM_64 => 0xcffaedfe;
+use constant CPU_TYPE_POWERPC => 18;
+use constant CPU_SUBTYPE_POWERPC_ALL => 0;
+
+my $infile = shift @ARGV or die("Missing input filename");
+my $outfile = shift @ARGV or die("Missing output filename");
+
+open IN, "<$infile" or die("Can't open $infile for reading: $!\n");
+open OUT, ">$outfile" or die("Can't open $outfile for writing: $!\n");
+
+binmode IN;
+binmode OUT;
+
+# Read the first 12 bytes, which includes the interesting fields of the header
+my $buffer;
+read(IN, $buffer, 12);
+
+my $magic = vec($buffer, 0, 32);
+if ($magic == MH_MAGIC || $magic == MH_MAGIC_64) {
+    # Big endian
+    # The low byte of cputype is at offset 7
+    vec($buffer, 7, 8) = CPU_TYPE_POWERPC;
+} elsif ($magic == MH_CIGAM || $magic == MH_CIGAM_64) {
+    # Little endian
+    # The low byte of cpytype is at offset 4
+    vec($buffer, 4, 8) = CPU_TYPE_POWERPC;
+} else {
+    $magic = '';
+    $magic .= sprintf("%02X ", $_) for unpack("CCCC", $buffer);
+    die("Invalid input. Unknown magic $magic\n");
+}
+vec($buffer, 2, 32) = CPU_SUBTYPE_POWERPC_ALL;
+
+print OUT $buffer;
+
+# Copy the rest
+while (!eof(IN)) {
+    read(IN, $buffer, 4096) and
+    print OUT $buffer or
+    die("Problem copying: $!\n");
+}
+close(IN);
+close(OUT);
diff --git a/tests/auto/corelib/plugin/qpluginloader/qpluginloader.pro b/tests/auto/corelib/plugin/qpluginloader/qpluginloader.pro
index 0cba19887e..8d117793bf 100644
--- a/tests/auto/corelib/plugin/qpluginloader/qpluginloader.pro
+++ b/tests/auto/corelib/plugin/qpluginloader/qpluginloader.pro
@@ -5,6 +5,7 @@ SUBDIRS	=	lib \
                 theplugin \
 		tst
 !win32: !mac: SUBDIRS += almostplugin
+macx-*: SUBDIRS += machtest
 TARGET = tst_qpluginloader
 
 # no special install rule for subdir
diff --git a/tests/auto/corelib/plugin/qpluginloader/tst/tst.pro b/tests/auto/corelib/plugin/qpluginloader/tst/tst.pro
index a7a9661a54..3894c90ae3 100644
--- a/tests/auto/corelib/plugin/qpluginloader/tst/tst.pro
+++ b/tests/auto/corelib/plugin/qpluginloader/tst/tst.pro
@@ -2,7 +2,8 @@ CONFIG += testcase
 CONFIG += parallel_test
 TARGET  = ../tst_qpluginloader
 QT = core testlib
-SOURCES = ../tst_qpluginloader.cpp
+contains(QT_CONFIG, private_tests): QT += core-private
+SOURCES = ../tst_qpluginloader.cpp ../fakeplugin.cpp
 HEADERS = ../theplugin/plugininterface.h
 CONFIG -= app_bundle
 
@@ -14,5 +15,5 @@ win32 {
     }
 }
 
-TESTDATA += ../elftest
+TESTDATA += ../elftest ../machtest
 DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0
diff --git a/tests/auto/corelib/plugin/qpluginloader/tst_qpluginloader.cpp b/tests/auto/corelib/plugin/qpluginloader/tst_qpluginloader.cpp
index cef4f53101..989d311ebf 100644
--- a/tests/auto/corelib/plugin/qpluginloader/tst_qpluginloader.cpp
+++ b/tests/auto/corelib/plugin/qpluginloader/tst_qpluginloader.cpp
@@ -44,6 +44,10 @@
 #include <qpluginloader.h>
 #include "theplugin/plugininterface.h"
 
+#if defined(QT_BUILD_INTERNAL) && defined(Q_OF_MACH_O)
+#  include <QtCore/private/qmachparser_p.h>
+#endif
+
 // Helper macros to let us know if some suffixes are valid
 #define bundle_VALID    false
 #define dylib_VALID     false
@@ -118,6 +122,8 @@ private slots:
     void deleteinstanceOnUnload();
     void loadDebugObj();
     void loadCorruptElf();
+    void loadMachO_data();
+    void loadMachO();
 #if defined (Q_OS_UNIX)
     void loadGarbage();
 #endif
@@ -311,6 +317,73 @@ void tst_QPluginLoader::loadCorruptElf()
 #endif
 }
 
+void tst_QPluginLoader::loadMachO_data()
+{
+#ifdef Q_OF_MACH_O
+    QTest::addColumn<int>("parseResult");
+
+    QTest::newRow("/dev/null") << int(QMachOParser::NotSuitable);
+    QTest::newRow("elftest/debugobj.so") << int(QMachOParser::NotSuitable);
+    QTest::newRow("tst_qpluginloader.cpp") << int(QMachOParser::NotSuitable);
+    QTest::newRow("tst_qpluginloader") << int(QMachOParser::NotSuitable);
+
+#  ifdef Q_PROCESSOR_X86_64
+    QTest::newRow("machtest/good.x86_64.dylib") << int(QMachOParser::QtMetaDataSection);
+    QTest::newRow("machtest/good.i386.dylib") << int(QMachOParser::NotSuitable);
+    QTest::newRow("machtest/good.fat.no-x86_64.dylib") << int(QMachOParser::NotSuitable);
+    QTest::newRow("machtest/good.fat.no-i386.dylib") << int(QMachOParser::QtMetaDataSection);
+#  elif defined(Q_PROCESSOR_X86_32)
+    QTest::newRow("machtest/good.i386.dylib") << int(QMachOParser::QtMetaDataSection);
+    QTest::newRow("machtest/good.x86_64.dylib") << int(QMachOParser::NotSuitable);
+    QTest::newRow("machtest/good.fat.no-i386.dylib") << int(QMachOParser::NotSuitable);
+    QTest::newRow("machtest/good.fat.no-x86_64.dylib") << int(QMachOParser::QtMetaDataSection);
+#  endif
+#  ifndef Q_PROCESSOR_POWER_64
+    QTest::newRow("machtest/good.ppc64.dylib") << int(QMachOParser::NotSuitable);
+#  endif
+
+    QTest::newRow("machtest/good.fat.all.dylib") << int(QMachOParser::QtMetaDataSection);
+    QTest::newRow("machtest/good.fat.stub-x86_64.dylib") << int(QMachOParser::NotSuitable);
+    QTest::newRow("machtest/good.fat.stub-i386.dylib") << int(QMachOParser::NotSuitable);
+#endif
+}
+
+void tst_QPluginLoader::loadMachO()
+{
+#ifdef Q_OF_MACH_O
+    QFile f(QFINDTESTDATA(QTest::currentDataTag()));
+    QVERIFY(f.open(QIODevice::ReadOnly));
+    QByteArray data = f.readAll();
+
+    long pos;
+    ulong len;
+    QString errorString;
+    int r = QMachOParser::parse(data.constData(), data.size(), f.fileName(), &errorString, &pos, &len);
+
+    QFETCH(int, parseResult);
+    QCOMPARE(r, parseResult);
+
+    if (r == QMachOParser::NotSuitable)
+        return;
+
+    QVERIFY(pos > 0);
+    QVERIFY(len >= sizeof(void*));
+    QVERIFY(pos + long(len) < data.size());
+    QCOMPARE(pos & (sizeof(void*) - 1), 0UL);
+
+    void *value = *(void**)(data.constData() + pos);
+    QCOMPARE(value, sizeof(void*) > 4 ? (void*)(0xc0ffeec0ffeeL) : (void*)0xc0ffee);
+
+    // now that we know it's valid, let's try to make it invalid
+    ulong offeredlen = pos;
+    do {
+        --offeredlen;
+        r = QMachOParser::parse(data.constData(), offeredlen, f.fileName(), &errorString, &pos, &len);
+        QVERIFY2(r == QMachOParser::NotSuitable, qPrintable(QString("Failed at size 0x%1").arg(offeredlen, 0, 16)));
+    } while (offeredlen);
+#endif
+}
+
 #if defined (Q_OS_UNIX)
 void tst_QPluginLoader::loadGarbage()
 {