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