10b57cec5SDimitry Andric //===- SafeStackLayout.h - SafeStack frame layout --------------*- C++ -*--===// 20b57cec5SDimitry Andric // 30b57cec5SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 40b57cec5SDimitry Andric // See https://llvm.org/LICENSE.txt for license information. 50b57cec5SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 60b57cec5SDimitry Andric // 70b57cec5SDimitry Andric //===----------------------------------------------------------------------===// 80b57cec5SDimitry Andric 90b57cec5SDimitry Andric #ifndef LLVM_LIB_CODEGEN_SAFESTACKLAYOUT_H 100b57cec5SDimitry Andric #define LLVM_LIB_CODEGEN_SAFESTACKLAYOUT_H 110b57cec5SDimitry Andric 120b57cec5SDimitry Andric #include "llvm/ADT/DenseMap.h" 130b57cec5SDimitry Andric #include "llvm/ADT/SmallVector.h" 145ffd83dbSDimitry Andric #include "llvm/Analysis/StackLifetime.h" 15*0fca6ea1SDimitry Andric #include "llvm/Support/Alignment.h" 160b57cec5SDimitry Andric 170b57cec5SDimitry Andric namespace llvm { 180b57cec5SDimitry Andric 190b57cec5SDimitry Andric class raw_ostream; 200b57cec5SDimitry Andric class Value; 210b57cec5SDimitry Andric 220b57cec5SDimitry Andric namespace safestack { 230b57cec5SDimitry Andric 240b57cec5SDimitry Andric /// Compute the layout of an unsafe stack frame. 250b57cec5SDimitry Andric class StackLayout { 260eae32dcSDimitry Andric Align MaxAlignment; 270b57cec5SDimitry Andric 280b57cec5SDimitry Andric struct StackRegion { 290b57cec5SDimitry Andric unsigned Start; 300b57cec5SDimitry Andric unsigned End; 315ffd83dbSDimitry Andric StackLifetime::LiveRange Range; 320b57cec5SDimitry Andric 330b57cec5SDimitry Andric StackRegion(unsigned Start, unsigned End, 345ffd83dbSDimitry Andric const StackLifetime::LiveRange &Range) 350b57cec5SDimitry Andric : Start(Start), End(End), Range(Range) {} 360b57cec5SDimitry Andric }; 370b57cec5SDimitry Andric 380b57cec5SDimitry Andric /// The list of current stack regions, sorted by StackRegion::Start. 390b57cec5SDimitry Andric SmallVector<StackRegion, 16> Regions; 400b57cec5SDimitry Andric 410b57cec5SDimitry Andric struct StackObject { 420b57cec5SDimitry Andric const Value *Handle; 43349cc55cSDimitry Andric unsigned Size; 440eae32dcSDimitry Andric Align Alignment; 455ffd83dbSDimitry Andric StackLifetime::LiveRange Range; 460b57cec5SDimitry Andric }; 470b57cec5SDimitry Andric 480b57cec5SDimitry Andric SmallVector<StackObject, 8> StackObjects; 490b57cec5SDimitry Andric 500b57cec5SDimitry Andric DenseMap<const Value *, unsigned> ObjectOffsets; 510eae32dcSDimitry Andric DenseMap<const Value *, Align> ObjectAlignments; 520b57cec5SDimitry Andric 530b57cec5SDimitry Andric void layoutObject(StackObject &Obj); 540b57cec5SDimitry Andric 550b57cec5SDimitry Andric public: 5681ad6265SDimitry Andric StackLayout(Align StackAlignment) : MaxAlignment(StackAlignment) {} 570b57cec5SDimitry Andric 580b57cec5SDimitry Andric /// Add an object to the stack frame. Value pointer is opaque and used as a 590b57cec5SDimitry Andric /// handle to retrieve the object's offset in the frame later. 600eae32dcSDimitry Andric void addObject(const Value *V, unsigned Size, Align Alignment, 615ffd83dbSDimitry Andric const StackLifetime::LiveRange &Range); 620b57cec5SDimitry Andric 630b57cec5SDimitry Andric /// Run the layout computation for all previously added objects. 640b57cec5SDimitry Andric void computeLayout(); 650b57cec5SDimitry Andric 660b57cec5SDimitry Andric /// Returns the offset to the object start in the stack frame. 670b57cec5SDimitry Andric unsigned getObjectOffset(const Value *V) { return ObjectOffsets[V]; } 680b57cec5SDimitry Andric 690b57cec5SDimitry Andric /// Returns the alignment of the object 700eae32dcSDimitry Andric Align getObjectAlignment(const Value *V) { return ObjectAlignments[V]; } 710b57cec5SDimitry Andric 720b57cec5SDimitry Andric /// Returns the size of the entire frame. 730b57cec5SDimitry Andric unsigned getFrameSize() { return Regions.empty() ? 0 : Regions.back().End; } 740b57cec5SDimitry Andric 750b57cec5SDimitry Andric /// Returns the alignment of the frame. 760eae32dcSDimitry Andric Align getFrameAlignment() { return MaxAlignment; } 770b57cec5SDimitry Andric 780b57cec5SDimitry Andric void print(raw_ostream &OS); 790b57cec5SDimitry Andric }; 800b57cec5SDimitry Andric 810b57cec5SDimitry Andric } // end namespace safestack 820b57cec5SDimitry Andric 830b57cec5SDimitry Andric } // end namespace llvm 840b57cec5SDimitry Andric 850b57cec5SDimitry Andric #endif // LLVM_LIB_CODEGEN_SAFESTACKLAYOUT_H 86