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14c858b69a
tests to fail. Basically, in the case of an empty vtable, SILVTable::create was allocating space for 0 entries (sensible!) but then the default ctor fires for the 1 element declared in the class, which would write off the end of the memory block, leading to unpleasantness in random places later. Swift SVN r11306
55 lines
2.0 KiB
C++
55 lines
2.0 KiB
C++
//===--- SILVTable.cpp - Defines the SILVTable class ----------------------===//
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//
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// This source file is part of the Swift.org open source project
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//
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// Copyright (c) 2014 - 2015 Apple Inc. and the Swift project authors
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// Licensed under Apache License v2.0 with Runtime Library Exception
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//
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// See http://swift.org/LICENSE.txt for license information
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// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
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//
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//===----------------------------------------------------------------------===//
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//
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// This file defines the SILVTable class, which is used to map dynamically
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// dispatchable class methods and properties to their concrete implementations
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// for a dynamic type. This information (FIXME) will be used by IRGen to lay
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// out class vtables, and can be used by devirtualization passes to lower
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// class_method instructions to static function_refs.
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//
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//===----------------------------------------------------------------------===//
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#include "swift/SIL/SILVTable.h"
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#include "swift/SIL/SILModule.h"
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using namespace swift;
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SILVTable *SILVTable::create(SILModule &M, ClassDecl *Class,
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ArrayRef<Pair> Entries) {
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// SILVTable contains one element declared in Entries. We must allocate
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// space for it, because its default ctor will write to it.
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unsigned NumTailElements = std::max((unsigned)Entries.size(), 1U)-1;
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void *buf = M.allocate(sizeof(SILVTable) + NumTailElements,
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alignof(SILVTable));
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SILVTable *vt = ::new (buf) SILVTable(Class, Entries);
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M.vtables.push_back(vt);
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return vt;
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}
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SILFunction *
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SILVTable::getImplementation(SILModule &M, SILDeclRef method) const {
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// FIXME: We should build a sidetable cache in the module. Linear lookup here
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// is lame.
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for (auto &entry : getEntries()) {
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// Check whether this mapping matches either the given decl directly or
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// one of its overridden decl.
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SILDeclRef m = method;
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do {
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if (entry.first == m)
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return entry.second;
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} while ((m = m.getOverridden()));
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}
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return nullptr;
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}
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