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7a626f63f7
slot. The easiest way to do that was to bundle up the information we care about for aggregate slots into a new structure which demands that its creators at least consider the question. I could probably be convinced that the ObjC 'needs GC' bit should be rolled into this structure. Implement generalized copy elision. The main obstacle here is that IR-generation must be much more careful about making sure that exactly llvm-svn: 113962
90 lines
3.1 KiB
C++
90 lines
3.1 KiB
C++
//===--- CGTemporaries.cpp - Emit LLVM Code for C++ temporaries -----------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This contains code dealing with C++ code generation of temporaries
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//
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//===----------------------------------------------------------------------===//
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#include "CodeGenFunction.h"
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using namespace clang;
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using namespace CodeGen;
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namespace {
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struct DestroyTemporary : EHScopeStack::Cleanup {
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const CXXTemporary *Temporary;
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llvm::Value *Addr;
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llvm::Value *CondPtr;
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DestroyTemporary(const CXXTemporary *Temporary, llvm::Value *Addr,
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llvm::Value *CondPtr)
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: Temporary(Temporary), Addr(Addr), CondPtr(CondPtr) {}
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void Emit(CodeGenFunction &CGF, bool IsForEH) {
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llvm::BasicBlock *CondEnd = 0;
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// If this is a conditional temporary, we need to check the condition
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// boolean and only call the destructor if it's true.
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if (CondPtr) {
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llvm::BasicBlock *CondBlock =
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CGF.createBasicBlock("temp.cond-dtor.call");
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CondEnd = CGF.createBasicBlock("temp.cond-dtor.cont");
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llvm::Value *Cond = CGF.Builder.CreateLoad(CondPtr);
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CGF.Builder.CreateCondBr(Cond, CondBlock, CondEnd);
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CGF.EmitBlock(CondBlock);
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}
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CGF.EmitCXXDestructorCall(Temporary->getDestructor(),
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Dtor_Complete, /*ForVirtualBase=*/false,
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Addr);
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if (CondPtr) {
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// Reset the condition to false.
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CGF.Builder.CreateStore(CGF.Builder.getFalse(), CondPtr);
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CGF.EmitBlock(CondEnd);
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}
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}
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};
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}
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/// Emits all the code to cause the given temporary to be cleaned up.
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void CodeGenFunction::EmitCXXTemporary(const CXXTemporary *Temporary,
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llvm::Value *Ptr) {
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llvm::AllocaInst *CondPtr = 0;
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// Check if temporaries need to be conditional. If so, we'll create a
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// condition boolean, initialize it to 0 and
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if (ConditionalBranchLevel != 0) {
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CondPtr = CreateTempAlloca(llvm::Type::getInt1Ty(VMContext), "cond");
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// Initialize it to false. This initialization takes place right after
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// the alloca insert point.
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InitTempAlloca(CondPtr, llvm::ConstantInt::getFalse(VMContext));
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// Now set it to true.
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Builder.CreateStore(Builder.getTrue(), CondPtr);
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}
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EHStack.pushCleanup<DestroyTemporary>(NormalAndEHCleanup,
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Temporary, Ptr, CondPtr);
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}
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RValue
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CodeGenFunction::EmitCXXExprWithTemporaries(const CXXExprWithTemporaries *E,
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AggValueSlot Slot) {
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RunCleanupsScope Scope(*this);
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return EmitAnyExpr(E->getSubExpr(), Slot);
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}
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LValue CodeGenFunction::EmitCXXExprWithTemporariesLValue(
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const CXXExprWithTemporaries *E) {
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RunCleanupsScope Scope(*this);
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return EmitLValue(E->getSubExpr());
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}
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