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63 lines
2.5 KiB
C++
63 lines
2.5 KiB
C++
//===----- llvm/Analysis/CaptureTracking.h - Pointer capture ----*- C++ -*-===//
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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 file contains routines that help determine which pointers are captured.
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_ANALYSIS_CAPTURETRACKING_H
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#define LLVM_ANALYSIS_CAPTURETRACKING_H
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namespace llvm {
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class Value;
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class Use;
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/// PointerMayBeCaptured - Return true if this pointer value may be captured
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/// by the enclosing function (which is required to exist). This routine can
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/// be expensive, so consider caching the results. The boolean ReturnCaptures
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/// specifies whether returning the value (or part of it) from the function
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/// counts as capturing it or not. The boolean StoreCaptures specified
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/// whether storing the value (or part of it) into memory anywhere
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/// automatically counts as capturing it or not.
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bool PointerMayBeCaptured(const Value *V,
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bool ReturnCaptures,
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bool StoreCaptures);
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/// This callback is used in conjunction with PointerMayBeCaptured. In
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/// addition to the interface here, you'll need to provide your own getters
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/// to see whether anything was captured.
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struct CaptureTracker {
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virtual ~CaptureTracker();
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/// tooManyUses - The depth of traversal has breached a limit. There may be
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/// capturing instructions that will not be passed into captured().
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virtual void tooManyUses() = 0;
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/// shouldExplore - This is the use of a value derived from the pointer.
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/// To prune the search (ie., assume that none of its users could possibly
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/// capture) return false. To search it, return true.
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///
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/// U->getUser() is always an Instruction.
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virtual bool shouldExplore(Use *U);
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/// captured - Information about the pointer was captured by the user of
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/// use U. Return true to stop the traversal or false to continue looking
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/// for more capturing instructions.
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virtual bool captured(Use *U) = 0;
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};
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/// PointerMayBeCaptured - Visit the value and the values derived from it and
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/// find values which appear to be capturing the pointer value. This feeds
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/// results into and is controlled by the CaptureTracker object.
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void PointerMayBeCaptured(const Value *V, CaptureTracker *Tracker);
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} // end namespace llvm
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#endif
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