Corelib: implement support for COFF-PE & DLLs in CYGWIN

Much of the code was already implemented for WIN32.
The patch adds relevant code and implements few exceptions for CYGWIN.

Change-Id: I0621075a8a989f64a4c2391d25220ef1686342d8
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/CMakeLists.txt

@@ -561,6 +561,11 @@ qt_internal_extend_target(Core CONDITION QT_FEATURE_thread AND WIN32
         synchronization
 )
 
+qt_internal_extend_target(Core CONDITION CYGWIN
+    SOURCES
+        global/qt_windows.h
+)
+
 qt_internal_extend_target(Core CONDITION WIN32
     SOURCES
         global/qoperatingsystemversion_win.cpp global/qoperatingsystemversion_win_p.h
@@ -1187,6 +1192,10 @@ qt_internal_extend_target(Core CONDITION QT_FEATURE_library
     SOURCES
         plugin/qlibrary.cpp plugin/qlibrary.h plugin/qlibrary_p.h
 )
+qt_internal_extend_target(Core CONDITION QT_FEATURE_library AND CYGWIN
+    SOURCES
+        plugin/qcoffpeparser.cpp plugin/qcoffpeparser_p.h
+)
 qt_internal_extend_target(Core CONDITION QT_FEATURE_library AND WIN32
     SOURCES
         plugin/qcoffpeparser.cpp plugin/qcoffpeparser_p.h

src/corelib/plugin/qcoffpeparser.cpp

@@ -9,6 +9,9 @@
 
 #include <optional>
 
+// Include minimal set of headers
+#define WIN32_LEAN_AND_MEAN
+#define NOGDI
 #include <qt_windows.h>
 
 QT_BEGIN_NAMESPACE

src/corelib/plugin/qcoffpeparser_p.h

@@ -18,7 +18,7 @@
 
 #include "qlibrary_p.h"
 
-#if defined(Q_OS_WIN)
+#if defined(Q_OS_WIN) || defined(Q_OS_CYGWIN)
 
 QT_BEGIN_NAMESPACE
 
@@ -29,6 +29,6 @@ struct QCoffPeParser
 
 QT_END_NAMESPACE
 
-#endif // defined(Q_OF_ELF) && defined(Q_CC_GNU)
+#endif // Q_OS_WIN || Q_OS_CYGWIN
 
 #endif // QCOFFPEPARSER_H

src/corelib/plugin/qfactoryloader.cpp

@@ -304,7 +304,7 @@ inline void QFactoryLoaderPrivate::updateSinglePath(const QString &path)
     qCDebug(lcFactoryLoader) << "checking directory path" << path << "...";
 
     QDirListing plugins(path,
-#if defined(Q_OS_WIN)
+#if defined(Q_OS_WIN) || defined(Q_OS_CYGWIN)
                 QStringList(QStringLiteral("*.dll")),
 #elif defined(Q_OS_ANDROID)
                 QStringList("libplugins_%1_*.so"_L1.arg(suffix)),

src/corelib/plugin/qlibrary.cpp

@@ -177,7 +177,7 @@ static QLibraryScanResult qt_find_pattern(const char *s, qsizetype s_len, QStrin
     return QElfParser::parse({s, s_len}, errMsg);
 #elif defined(Q_OF_MACH_O)
     return QMachOParser::parse(s, s_len, errMsg);
-#elif defined(Q_OS_WIN)
+#elif defined(Q_OS_WIN) || defined(Q_OS_CYGWIN)
     return QCoffPeParser::parse({s, s_len}, errMsg);
 #else
 #   warning "Qt does not know how to efficiently parse your platform's binary format; using slow fall-back."
@@ -615,7 +615,7 @@ QtPluginInstanceFunction QLibraryPrivate::loadPlugin()
  */
 bool QLibrary::isLibrary(const QString &fileName)
 {
-#if defined(Q_OS_WIN)
+#if defined(Q_OS_WIN) || defined(Q_OS_CYGWIN)
     return fileName.endsWith(".dll"_L1, Qt::CaseInsensitive);
 #else // Generic Unix
 # if defined(Q_OS_DARWIN)

src/corelib/plugin/qlibrary_p.h

@@ -83,6 +83,8 @@ public:
     {
 #ifdef Q_OS_WIN
         return {};
+#elif defined(Q_OS_CYGWIN)
+        return u"cyg";
 #else
         return u"lib";
 #endif

src/corelib/plugin/qlibrary_unix.cpp

@@ -53,6 +53,12 @@ QStringList QLibraryPrivate::suffixes_sys(const QString &fullVersion)
     } else {
         suffixes << ".sl"_L1;
     }
+#elif defined(Q_OS_CYGWIN)
+    if (!fullVersion.isEmpty()) {
+        suffixes << "-%1.dll"_L1.arg(fullVersion);
+    } else {
+        suffixes << QStringLiteral(".dll");
+    }
 #elif defined(Q_OS_AIX)
     suffixes << ".a";