1 //===- ASanStackFrameLayout.h - ComputeASanStackFrameLayout -----*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This header defines ComputeASanStackFrameLayout and auxiliary data structs. 10 // 11 //===----------------------------------------------------------------------===// 12 #ifndef LLVM_TRANSFORMS_UTILS_ASANSTACKFRAMELAYOUT_H 13 #define LLVM_TRANSFORMS_UTILS_ASANSTACKFRAMELAYOUT_H 14 #include "llvm/ADT/SmallString.h" 15 #include "llvm/ADT/SmallVector.h" 16 17 namespace llvm { 18 19 class AllocaInst; 20 21 // These magic constants should be the same as in 22 // in asan_internal.h from ASan runtime in compiler-rt. 23 static const int kAsanStackLeftRedzoneMagic = 0xf1; 24 static const int kAsanStackMidRedzoneMagic = 0xf2; 25 static const int kAsanStackRightRedzoneMagic = 0xf3; 26 static const int kAsanStackUseAfterReturnMagic = 0xf5; 27 static const int kAsanStackUseAfterScopeMagic = 0xf8; 28 29 // Input/output data struct for ComputeASanStackFrameLayout. 30 struct ASanStackVariableDescription { 31 const char *Name; // Name of the variable that will be displayed by asan 32 // if a stack-related bug is reported. 33 uint64_t Size; // Size of the variable in bytes. 34 size_t LifetimeSize; // Size in bytes to use for lifetime analysis check. 35 // Will be rounded up to Granularity. 36 size_t Alignment; // Alignment of the variable (power of 2). 37 AllocaInst *AI; // The actual AllocaInst. 38 size_t Offset; // Offset from the beginning of the frame; 39 // set by ComputeASanStackFrameLayout. 40 unsigned Line; // Line number. 41 }; 42 43 // Output data struct for ComputeASanStackFrameLayout. 44 struct ASanStackFrameLayout { 45 size_t Granularity; // Shadow granularity. 46 size_t FrameAlignment; // Alignment for the entire frame. 47 size_t FrameSize; // Size of the frame in bytes. 48 }; 49 50 ASanStackFrameLayout ComputeASanStackFrameLayout( 51 // The array of stack variables. The elements may get reordered and changed. 52 SmallVectorImpl<ASanStackVariableDescription> &Vars, 53 // AddressSanitizer's shadow granularity. Usually 8, may also be 16, 32, 64. 54 size_t Granularity, 55 // The minimal size of the left-most redzone (header). 56 // At least 4 pointer sizes, power of 2, and >= Granularity. 57 // The resulting FrameSize should be multiple of MinHeaderSize. 58 size_t MinHeaderSize); 59 60 // Compute frame description, see DescribeAddressIfStack in ASan runtime. 61 SmallString<64> ComputeASanStackFrameDescription( 62 const SmallVectorImpl<ASanStackVariableDescription> &Vars); 63 64 // Returns shadow bytes with marked red zones. This shadow represents the state 65 // if the stack frame when all local variables are inside of the own scope. 66 SmallVector<uint8_t, 64> 67 GetShadowBytes(const SmallVectorImpl<ASanStackVariableDescription> &Vars, 68 const ASanStackFrameLayout &Layout); 69 70 // Returns shadow bytes with marked red zones and after scope. This shadow 71 // represents the state if the stack frame when all local variables are outside 72 // of the own scope. 73 SmallVector<uint8_t, 64> GetShadowBytesAfterScope( 74 // The array of stack variables. The elements may get reordered and changed. 75 const SmallVectorImpl<ASanStackVariableDescription> &Vars, 76 const ASanStackFrameLayout &Layout); 77 78 } // llvm namespace 79 80 #endif // LLVM_TRANSFORMS_UTILS_ASANSTACKFRAMELAYOUT_H 81
Indexes created Mon Jun 15 00:25:07 UTC 2026