84 lines
2.4 KiB
C
84 lines
2.4 KiB
C
|
//===- SafeStackLayout.h - SafeStack frame layout --------------*- C++ -*--===//
|
||
|
//
|
||
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
||
|
// See https://llvm.org/LICENSE.txt for license information.
|
||
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
||
|
//
|
||
|
//===----------------------------------------------------------------------===//
|
||
|
|
||
|
#ifndef LLVM_LIB_CODEGEN_SAFESTACKLAYOUT_H
|
||
|
#define LLVM_LIB_CODEGEN_SAFESTACKLAYOUT_H
|
||
|
|
||
|
#include "llvm/ADT/DenseMap.h"
|
||
|
#include "llvm/ADT/SmallVector.h"
|
||
|
#include "llvm/Analysis/StackLifetime.h"
|
||
|
|
||
|
namespace llvm {
|
||
|
|
||
|
class raw_ostream;
|
||
|
class Value;
|
||
|
|
||
|
namespace safestack {
|
||
|
|
||
|
/// Compute the layout of an unsafe stack frame.
|
||
|
class StackLayout {
|
||
|
unsigned MaxAlignment;
|
||
|
|
||
|
struct StackRegion {
|
||
|
unsigned Start;
|
||
|
unsigned End;
|
||
|
StackLifetime::LiveRange Range;
|
||
|
|
||
|
StackRegion(unsigned Start, unsigned End,
|
||
|
const StackLifetime::LiveRange &Range)
|
||
|
: Start(Start), End(End), Range(Range) {}
|
||
|
};
|
||
|
|
||
|
/// The list of current stack regions, sorted by StackRegion::Start.
|
||
|
SmallVector<StackRegion, 16> Regions;
|
||
|
|
||
|
struct StackObject {
|
||
|
const Value *Handle;
|
||
|
unsigned Size, Alignment;
|
||
|
StackLifetime::LiveRange Range;
|
||
|
};
|
||
|
|
||
|
SmallVector<StackObject, 8> StackObjects;
|
||
|
|
||
|
DenseMap<const Value *, unsigned> ObjectOffsets;
|
||
|
DenseMap<const Value *, unsigned> ObjectAlignments;
|
||
|
|
||
|
void layoutObject(StackObject &Obj);
|
||
|
|
||
|
public:
|
||
|
StackLayout(unsigned StackAlignment) : MaxAlignment(StackAlignment) {}
|
||
|
|
||
|
/// Add an object to the stack frame. Value pointer is opaque and used as a
|
||
|
/// handle to retrieve the object's offset in the frame later.
|
||
|
void addObject(const Value *V, unsigned Size, unsigned Alignment,
|
||
|
const StackLifetime::LiveRange &Range);
|
||
|
|
||
|
/// Run the layout computation for all previously added objects.
|
||
|
void computeLayout();
|
||
|
|
||
|
/// Returns the offset to the object start in the stack frame.
|
||
|
unsigned getObjectOffset(const Value *V) { return ObjectOffsets[V]; }
|
||
|
|
||
|
/// Returns the alignment of the object
|
||
|
unsigned getObjectAlignment(const Value *V) { return ObjectAlignments[V]; }
|
||
|
|
||
|
/// Returns the size of the entire frame.
|
||
|
unsigned getFrameSize() { return Regions.empty() ? 0 : Regions.back().End; }
|
||
|
|
||
|
/// Returns the alignment of the frame.
|
||
|
unsigned getFrameAlignment() { return MaxAlignment; }
|
||
|
|
||
|
void print(raw_ostream &OS);
|
||
|
};
|
||
|
|
||
|
} // end namespace safestack
|
||
|
|
||
|
} // end namespace llvm
|
||
|
|
||
|
#endif // LLVM_LIB_CODEGEN_SAFESTACKLAYOUT_H
|