Adding upstream version 7.0.6-dfsg.upstream/7.0.6-dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 122 insertions, 0 deletions

diff --git a/include/iprt/ldrlazy.h b/include/iprt/ldrlazy.h
new file mode 100644
index 00000000..0fa788da
--- /dev/null
+++ b/include/iprt/ldrlazy.h
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+/** @file
+ * IPRT - Lazy share library linking (2nd try).
+ */
+
+/*
+ * Copyright (C) 2013-2022 Oracle and/or its affiliates.
+ *
+ * This file is part of VirtualBox base platform packages, as
+ * available from https://www.virtualbox.org.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, in version 3 of the
+ * License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <https://www.gnu.org/licenses>.
+ *
+ * The contents of this file may alternatively be used under the terms
+ * of the Common Development and Distribution License Version 1.0
+ * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
+ * in the VirtualBox distribution, in which case the provisions of the
+ * CDDL are applicable instead of those of the GPL.
+ *
+ * You may elect to license modified versions of this file under the
+ * terms and conditions of either the GPL or the CDDL or both.
+ *
+ * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
+ */
+
+#ifndef IPRT_INCLUDED_ldrlazy_h
+#define IPRT_INCLUDED_ldrlazy_h
+#ifndef RT_WITHOUT_PRAGMA_ONCE
+# pragma once
+#endif
+
+#include <iprt/ldr.h>
+
+/** @defgroup grp_rt_ldrlazy        RTLdrLazy - Lazy shared library linking.
+ * @ingroup grp_rt
+ *
+ * This is a set of macros which will produce code for dynamically loading and
+ * resolving symbols in shared libraries (DLLs).
+ *
+ * There is an assembly language alternative to this that only requires writing
+ * a list of symbols in a format similar to what the microsoft linkers take as
+ * input when producing DLLs and import libraries.  That is probably preferable
+ * over this code.  See src/bldprog/VBoxDef2LazyLoad.cpp.
+ *
+ * @{
+ */
+
+
+/**
+ * Defines a module for use in lazy resolving.
+ *
+ * @param   a_Mod       The module name (C name).
+ * @param   a_pszFile   The file to tell RTLdrLoad to load.
+ */
+#define RTLDRLAZY_MODULE(a_Mod, a_pszFile) \
+    RTLDRLAZY_MODULE_EX(a_Mod, a_pszFile, RTLdrLoad)
+
+/**
+ * Defines a module for use in lazy resolving.
+ *
+ * @param   a_Mod       The module name (C name).
+ * @param   a_pszFile   The file to tell RTLdrLoad to load.
+ * @param   a_pfnLoadIt Function to call for loading the DLL, replacing
+ *                      RTLdrLoad.
+ */
+#define RTLDRLAZY_MODULE_EX(a_Mod, a_pszFile, a_pfnLoadIt) \
+    static bool rtLdrLazy_##a_Mod##_Resolve(const char *pszName, void **ppvSymbol) \
+    { \
+        static RTLDRMOD volatile    s_hMod    = NIL_RTLDRMOD; \
+        static bool volatile        s_fLoaded = false; \
+        RTLDRMOD    hMod; \
+        int         rc; \
+        if (!s_fLoaded) \
+        { \
+            rc = a_pfnLoadIt(a_pszFile, &hMod); \
+            s_hMod = RT_SUCCESS(rc) ? hMod : NIL_RTLDRMOD; \
+            s_fLoaded = true; \
+            if (RT_FAILURE(rc)) \
+                return false; \
+        } \
+        hMod = s_hMod; \
+        if (hMod == NIL_RTLDRMOD) \
+            return false; \
+        rc = RTLdrGetSymbol(hMod, pszName, ppvSymbol); \
+        return RT_SUCCESS(rc); \
+    }
+
+
+
+/** Function name mangler for preventing collision with system prototypes. */
+#define RTLDRLAZY_FUNC_NAME(a_Mod, a_Name) a_Mod##__##a_Name
+
+/**
+ * Defines a function that should be lazily resolved.
+ */
+#define RTLDRLAZY_FUNC(a_Mod, a_RetType, a_CallConv, a_Name, a_ParamDecl, a_ParamNames, a_ErrRet) \
+    DECLINLINE(a_RetType) RTLDRLAZY_FUNC_NAME(a_Mod, a_Name) a_ParamDecl \
+    { \
+        static a_RetType (a_CallConv * s_pfn) a_ParamDecl; \
+        if (!s_pfn) \
+        { \
+            if (!rtLdrLazy_##a_Mod##_Resolve(#a_Name, (void **)&s_pfn)) \
+                return a_ErrRet; \
+        } \
+        return s_pfn a_ParamNames; \
+    }
+
+
+/** @} */
+
+#endif /* !IPRT_INCLUDED_ldrlazy_h */
+