59 lines
1.5 KiB
C
59 lines
1.5 KiB
C
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// Scintilla source code edit control
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/** @file WinTypes.h
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** Implement safe release of COM objects and access to functions in DLLs.
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** Header contains all implementation - there is no .cxx file.
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**/
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// Copyright 2020-2021 by Neil Hodgson <neilh@scintilla.org>
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// The License.txt file describes the conditions under which this software may be distributed.
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#ifndef WINTYPES_H
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#define WINTYPES_H
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namespace Scintilla::Internal {
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// Release an IUnknown* and set to nullptr.
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// While IUnknown::Release must be noexcept, it isn't marked as such so produces
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// warnings which are avoided by the catch.
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template <class T>
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inline void ReleaseUnknown(T *&ppUnknown) noexcept {
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if (ppUnknown) {
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try {
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ppUnknown->Release();
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} catch (...) {
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// Never occurs
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}
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ppUnknown = nullptr;
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}
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}
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struct UnknownReleaser {
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// Called by unique_ptr to destroy/free the resource
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template <class T>
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void operator()(T *pUnknown) noexcept {
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try {
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pUnknown->Release();
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} catch (...) {
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// IUnknown::Release must not throw, ignore if it does.
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}
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}
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};
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/// Find a function in a DLL and convert to a function pointer.
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/// This avoids undefined and conditionally defined behaviour.
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template<typename T>
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inline T DLLFunction(HMODULE hModule, LPCSTR lpProcName) noexcept {
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if (!hModule) {
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return nullptr;
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}
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FARPROC function = ::GetProcAddress(hModule, lpProcName);
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static_assert(sizeof(T) == sizeof(function));
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T fp {};
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memcpy(&fp, &function, sizeof(T));
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return fp;
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}
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}
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#endif
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