1b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik//===------------------ mach-o/compact_unwind_encoding.h ------------------===// 2b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 3b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// The LLVM Compiler Infrastructure 4b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 5b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// This file is dual licensed under the MIT and the University of Illinois Open 6b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// Source Licenses. See LICENSE.TXT for details. 7b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 8b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 9b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// Darwin's alternative to dwarf based unwind encodings. 10b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 11b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik//===----------------------------------------------------------------------===// 12b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 13b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 14b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik#ifndef __COMPACT_UNWIND_ENCODING__ 15b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik#define __COMPACT_UNWIND_ENCODING__ 16b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 17b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik#include <stdint.h> 18b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 19b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 20b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// Compilers can emit standard Dwarf FDEs in the __TEXT,__eh_frame section 21b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// of object files. Or compilers can emit compact unwind information in 22b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// the __LD,__compact_unwind section. 23b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 24b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// When the linker creates a final linked image, it will create a 25b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// __TEXT,__unwind_info section. This section is a small and fast way for the 26b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// runtime to access unwind info for any given function. If the compiler 27b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// emitted compact unwind info for the function, that compact unwind info will 28b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// be encoded in the __TEXT,__unwind_info section. If the compiler emitted 29b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// dwarf unwind info, the __TEXT,__unwind_info section will contain the offset 30b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// of the FDE in the __TEXT,__eh_frame section in the final linked image. 31b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 32b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// Note: Previously, the linker would transform some dwarf unwind infos into 33b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// compact unwind info. But that is fragile and no longer done. 34b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 35b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 36b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 37b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// The compact unwind endoding is a 32-bit value which encoded in an 38b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// architecture specific way, which registers to restore from where, and how 39b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// to unwind out of the function. 40b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 41b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledziktypedef uint32_t compact_unwind_encoding_t; 42b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 43b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 44b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// architecture independent bits 45b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzikenum { 46b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_IS_NOT_FUNCTION_START = 0x80000000, 47b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_HAS_LSDA = 0x40000000, 48b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_PERSONALITY_MASK = 0x30000000, 49b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik}; 50b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 51b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 52b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 53b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 54b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 55b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// x86 56b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 57b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 1-bit: start 58b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 1-bit: has lsda 59b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 2-bit: personality index 60b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 61b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 4-bits: 0=old, 1=ebp based, 2=stack-imm, 3=stack-ind, 4=dwarf 62b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// ebp based: 63b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 15-bits (5*3-bits per reg) register permutation 64b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 8-bits for stack offset 65b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// frameless: 66b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 8-bits stack size 67b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 3-bits stack adjust 68b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 3-bits register count 69b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 10-bits register permutation 70b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 71b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzikenum { 72b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_MODE_MASK = 0x0F000000, 73b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_MODE_EBP_FRAME = 0x01000000, 74b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_MODE_STACK_IMMD = 0x02000000, 75b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_MODE_STACK_IND = 0x03000000, 76b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_MODE_DWARF = 0x04000000, 77b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 78b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_EBP_FRAME_REGISTERS = 0x00007FFF, 79b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_EBP_FRAME_OFFSET = 0x00FF0000, 80b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 81b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_FRAMELESS_STACK_SIZE = 0x00FF0000, 82b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_FRAMELESS_STACK_ADJUST = 0x0000E000, 83b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_FRAMELESS_STACK_REG_COUNT = 0x00001C00, 84b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_FRAMELESS_STACK_REG_PERMUTATION = 0x000003FF, 85b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 86b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_DWARF_SECTION_OFFSET = 0x00FFFFFF, 87b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik}; 88b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 89b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzikenum { 90b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_REG_NONE = 0, 91b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_REG_EBX = 1, 92b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_REG_ECX = 2, 93b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_REG_EDX = 3, 94b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_REG_EDI = 4, 95b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_REG_ESI = 5, 96b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_REG_EBP = 6, 97b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik}; 98b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 99b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 100b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// For x86 there are four modes for the compact unwind encoding: 101b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// UNWIND_X86_MODE_EBP_FRAME: 102b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// EBP based frame where EBP is push on stack immediately after return address, 103b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// then ESP is moved to EBP. Thus, to unwind ESP is restored with the current 104b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// EPB value, then EBP is restored by popping off the stack, and the return 105b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// is done by popping the stack once more into the pc. 106b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// All non-volatile registers that need to be restored must have been saved 107b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// in a small range in the stack that starts EBP-4 to EBP-1020. The offset/4 108b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// is encoded in the UNWIND_X86_EBP_FRAME_OFFSET bits. The registers saved 109b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// are encoded in the UNWIND_X86_EBP_FRAME_REGISTERS bits as five 3-bit entries. 110b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// Each entry contains which register to restore. 111b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// UNWIND_X86_MODE_STACK_IMMD: 112b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// A "frameless" (EBP not used as frame pointer) function with a small 113b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// constant stack size. To return, a constant (encoded in the compact 114b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// unwind encoding) is added to the ESP. Then the return is done by 115b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// popping the stack into the pc. 116b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// All non-volatile registers that need to be restored must have been saved 117b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// on the stack immediately after the return address. The stack_size/4 is 118b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// encoded in the UNWIND_X86_FRAMELESS_STACK_SIZE (max stack size is 1024). 119b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// The number of registers saved is encoded in UNWIND_X86_FRAMELESS_STACK_REG_COUNT. 120b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// UNWIND_X86_FRAMELESS_STACK_REG_PERMUTATION constains which registers were 121b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// saved and their order. 122b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// UNWIND_X86_MODE_STACK_IND: 123b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// A "frameless" (EBP not used as frame pointer) function large constant 124b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// stack size. This case is like the previous, except the stack size is too 125b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// large to encode in the compact unwind encoding. Instead it requires that 126b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// the function contains "subl $nnnnnnnn,ESP" in its prolog. The compact 127b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// encoding contains the offset to the nnnnnnnn value in the function in 128b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// UNWIND_X86_FRAMELESS_STACK_SIZE. 129b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// UNWIND_X86_MODE_DWARF: 130b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// No compact unwind encoding is available. Instead the low 24-bits of the 131b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// compact encoding is the offset of the dwarf FDE in the __eh_frame section. 132b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// This mode is never used in object files. It is only generated by the 133b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// linker in final linked images which have only dwarf unwind info for a 134b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// function. 135b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 136b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// The following is the algorithm used to create the permutation encoding used 137b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// with frameless stacks. It is passed the number of registers to be saved and 138b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// an array of the register numbers saved. 139b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 140b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik//uint32_t permute_encode(uint32_t registerCount, const uint32_t registers[6]) 141b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik//{ 142b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// uint32_t renumregs[6]; 143b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// for (int i=6-registerCount; i < 6; ++i) { 144b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// int countless = 0; 145b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// for (int j=6-registerCount; j < i; ++j) { 146b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// if ( registers[j] < registers[i] ) 147b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// ++countless; 148b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// } 149b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// renumregs[i] = registers[i] - countless -1; 150b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// } 151b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// uint32_t permutationEncoding = 0; 152b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// switch ( registerCount ) { 153b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// case 6: 154b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// permutationEncoding |= (120*renumregs[0] + 24*renumregs[1] 155b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// + 6*renumregs[2] + 2*renumregs[3] 156b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// + renumregs[4]); 157b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// break; 158b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// case 5: 159b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// permutationEncoding |= (120*renumregs[1] + 24*renumregs[2] 160b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// + 6*renumregs[3] + 2*renumregs[4] 161b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// + renumregs[5]); 162b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// break; 163b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// case 4: 164b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// permutationEncoding |= (60*renumregs[2] + 12*renumregs[3] 165b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// + 3*renumregs[4] + renumregs[5]); 166b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// break; 167b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// case 3: 168b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// permutationEncoding |= (20*renumregs[3] + 4*renumregs[4] 169b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// + renumregs[5]); 170b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// break; 171b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// case 2: 172b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// permutationEncoding |= (5*renumregs[4] + renumregs[5]); 173b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// break; 174b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// case 1: 175b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// permutationEncoding |= (renumregs[5]); 176b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// break; 177b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// } 178b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// return permutationEncoding; 179b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik//} 180b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 181b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 182b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 183b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 184b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 185b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 186b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// x86_64 187b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 188b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 1-bit: start 189b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 1-bit: has lsda 190b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 2-bit: personality index 191b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 192b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 4-bits: 0=old, 1=rbp based, 2=stack-imm, 3=stack-ind, 4=dwarf 193b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// rbp based: 194b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 15-bits (5*3-bits per reg) register permutation 195b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 8-bits for stack offset 196b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// frameless: 197b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 8-bits stack size 198b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 3-bits stack adjust 199b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 3-bits register count 200b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 10-bits register permutation 201b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 202b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzikenum { 203b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_64_MODE_MASK = 0x0F000000, 204b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_64_MODE_RBP_FRAME = 0x01000000, 205b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_64_MODE_STACK_IMMD = 0x02000000, 206b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_64_MODE_STACK_IND = 0x03000000, 207b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_64_MODE_DWARF = 0x04000000, 208b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 209b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_64_RBP_FRAME_REGISTERS = 0x00007FFF, 210b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_64_RBP_FRAME_OFFSET = 0x00FF0000, 211b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 212b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_64_FRAMELESS_STACK_SIZE = 0x00FF0000, 213b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_64_FRAMELESS_STACK_ADJUST = 0x0000E000, 214b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_64_FRAMELESS_STACK_REG_COUNT = 0x00001C00, 215b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_64_FRAMELESS_STACK_REG_PERMUTATION = 0x000003FF, 216b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 217b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_64_DWARF_SECTION_OFFSET = 0x00FFFFFF, 218b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik}; 219b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 220b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzikenum { 221b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_64_REG_NONE = 0, 222b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_64_REG_RBX = 1, 223b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_64_REG_R12 = 2, 224b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_64_REG_R13 = 3, 225b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_64_REG_R14 = 4, 226b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_64_REG_R15 = 5, 227b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_X86_64_REG_RBP = 6, 228b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik}; 229b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 230b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// For x86_64 there are four modes for the compact unwind encoding: 231b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// UNWIND_X86_64_MODE_RBP_FRAME: 232b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// RBP based frame where RBP is push on stack immediately after return address, 233b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// then RSP is moved to RBP. Thus, to unwind RSP is restored with the current 234b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// EPB value, then RBP is restored by popping off the stack, and the return 235b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// is done by popping the stack once more into the pc. 236b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// All non-volatile registers that need to be restored must have been saved 237b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// in a small range in the stack that starts RBP-8 to RBP-1020. The offset/4 238b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// is encoded in the UNWIND_X86_64_RBP_FRAME_OFFSET bits. The registers saved 239b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// are encoded in the UNWIND_X86_64_RBP_FRAME_REGISTERS bits as five 3-bit entries. 240b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// Each entry contains which register to restore. 241b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// UNWIND_X86_64_MODE_STACK_IMMD: 242b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// A "frameless" (RBP not used as frame pointer) function with a small 243b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// constant stack size. To return, a constant (encoded in the compact 244b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// unwind encoding) is added to the RSP. Then the return is done by 245b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// popping the stack into the pc. 246b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// All non-volatile registers that need to be restored must have been saved 247b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// on the stack immediately after the return address. The stack_size/4 is 248b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// encoded in the UNWIND_X86_64_FRAMELESS_STACK_SIZE (max stack size is 1024). 249b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// The number of registers saved is encoded in UNWIND_X86_64_FRAMELESS_STACK_REG_COUNT. 250b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// UNWIND_X86_64_FRAMELESS_STACK_REG_PERMUTATION constains which registers were 251b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// saved and their order. 252b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// UNWIND_X86_64_MODE_STACK_IND: 253b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// A "frameless" (RBP not used as frame pointer) function large constant 254b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// stack size. This case is like the previous, except the stack size is too 255b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// large to encode in the compact unwind encoding. Instead it requires that 256b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// the function contains "subq $nnnnnnnn,RSP" in its prolog. The compact 257b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// encoding contains the offset to the nnnnnnnn value in the function in 258b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// UNWIND_X86_64_FRAMELESS_STACK_SIZE. 259b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// UNWIND_X86_64_MODE_DWARF: 260b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// No compact unwind encoding is available. Instead the low 24-bits of the 261b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// compact encoding is the offset of the dwarf FDE in the __eh_frame section. 262b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// This mode is never used in object files. It is only generated by the 263b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// linker in final linked images which have only dwarf unwind info for a 264b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// function. 265b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 266b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 267b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 268b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// ARM64 269b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 270b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 1-bit: start 271b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 1-bit: has lsda 272b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 2-bit: personality index 273b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 274e45805f0d3f8dafef1297cc7dc49e610713f023bDan Albert// 4-bits: 4=frame-based, 3=dwarf, 2=frameless 275b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// frameless: 276b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 12-bits of stack size 277b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// frame-based: 278b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 4-bits D reg pairs saved 279b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 5-bits X reg pairs saved 280b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// dwarf: 281b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 24-bits offset of dwarf FDE in __eh_frame section 282b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 283b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzikenum { 284b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_ARM64_MODE_MASK = 0x0F000000, 285b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_ARM64_MODE_FRAMELESS = 0x02000000, 286b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_ARM64_MODE_DWARF = 0x03000000, 287b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_ARM64_MODE_FRAME = 0x04000000, 288b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 289b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_ARM64_FRAME_X19_X20_PAIR = 0x00000001, 290b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_ARM64_FRAME_X21_X22_PAIR = 0x00000002, 291b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_ARM64_FRAME_X23_X24_PAIR = 0x00000004, 292b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_ARM64_FRAME_X25_X26_PAIR = 0x00000008, 293b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_ARM64_FRAME_X27_X28_PAIR = 0x00000010, 294b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_ARM64_FRAME_D8_D9_PAIR = 0x00000100, 295b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_ARM64_FRAME_D10_D11_PAIR = 0x00000200, 296b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_ARM64_FRAME_D12_D13_PAIR = 0x00000400, 297b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_ARM64_FRAME_D14_D15_PAIR = 0x00000800, 298b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 299b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_ARM64_FRAMELESS_STACK_SIZE_MASK = 0x00FFF000, 300b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik UNWIND_ARM64_DWARF_SECTION_OFFSET = 0x00FFFFFF, 301b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik}; 302b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// For arm64 there are three modes for the compact unwind encoding: 303b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// UNWIND_ARM64_MODE_FRAME: 304b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// This is a standard arm64 prolog where FP/LR are immediately pushed on the 305b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// stack, then SP is copied to FP. If there are any non-volatile registers 306b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// saved, then are copied into the stack frame in pairs in a contiguous 307b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// range right below the saved FP/LR pair. Any subset of the five X pairs 308b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// and four D pairs can be saved, but the memory layout must be in register 309b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// number order. 310b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// UNWIND_ARM64_MODE_FRAMELESS: 311b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// A "frameless" leaf function, where FP/LR are not saved. The return address 312b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// remains in LR throughout the function. If any non-volatile registers 313b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// are saved, they must be pushed onto the stack before any stack space is 314b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// allocated for local variables. The stack sized (including any saved 315b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// non-volatile registers) divided by 16 is encoded in the bits 316b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// UNWIND_ARM64_FRAMELESS_STACK_SIZE_MASK. 317b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// UNWIND_ARM64_MODE_DWARF: 318b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// No compact unwind encoding is available. Instead the low 24-bits of the 319b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// compact encoding is the offset of the dwarf FDE in the __eh_frame section. 320b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// This mode is never used in object files. It is only generated by the 321b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// linker in final linked images which have only dwarf unwind info for a 322b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// function. 323b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 324b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 325b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 326b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 327b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 328b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 329b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik//////////////////////////////////////////////////////////////////////////////// 330b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 331b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// Relocatable Object Files: __LD,__compact_unwind 332b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 333b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik//////////////////////////////////////////////////////////////////////////////// 334b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 335b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 336b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// A compiler can generated compact unwind information for a function by adding 337b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// a "row" to the __LD,__compact_unwind section. This section has the 338b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// S_ATTR_DEBUG bit set, so the section will be ignored by older linkers. 339b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// It is removed by the new linker, so never ends up in final executables. 340b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// This section is a table, initially with one row per function (that needs 341b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// unwind info). The table columns and some conceptual entries are: 342b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 343b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// range-start pointer to start of function/range 344b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// range-length 345b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// compact-unwind-encoding 32-bit encoding 346b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// personality-function or zero if no personality function 347b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// lsda or zero if no LSDA data 348b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 349b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// The length and encoding fields are 32-bits. The other are all pointer sized. 350b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 351b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// In x86_64 assembly, these entry would look like: 352b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 353b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// .section __LD,__compact_unwind,regular,debug 354b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 355b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// #compact unwind for _foo 356b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// .quad _foo 357b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// .set L1,LfooEnd-_foo 358b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// .long L1 359b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// .long 0x01010001 360b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// .quad 0 361b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// .quad 0 362b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 363b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// #compact unwind for _bar 364b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// .quad _bar 365b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// .set L2,LbarEnd-_bar 366b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// .long L2 367b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// .long 0x01020011 368b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// .quad __gxx_personality 369b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// .quad except_tab1 370b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 371b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 372b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// Notes: There is no need for any labels in the the __compact_unwind section. 373b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// The use of the .set directive is to force the evaluation of the 374b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// range-length at assembly time, instead of generating relocations. 375b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 376b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// To support future compiler optimizations where which non-volatile registers 377b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// are saved changes within a function (e.g. delay saving non-volatiles until 378b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// necessary), there can by multiple lines in the __compact_unwind table for one 379b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// function, each with a different (non-overlapping) range and each with 380b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// different compact unwind encodings that correspond to the non-volatiles 381b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// saved at that range of the function. 382b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 383b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// If a particular function is so wacky that there is no compact unwind way 384b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// to encode it, then the compiler can emit traditional dwarf unwind info. 385b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// The runtime will use which ever is available. 386b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 387b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// Runtime support for compact unwind encodings are only available on 10.6 388b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// and later. So, the compiler should not generate it when targeting pre-10.6. 389b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 390b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 391b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 392b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 393b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik//////////////////////////////////////////////////////////////////////////////// 394b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 395b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// Final Linked Images: __TEXT,__unwind_info 396b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 397b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik//////////////////////////////////////////////////////////////////////////////// 398b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 399b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 400b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// The __TEXT,__unwind_info section is laid out for an efficient two level lookup. 401b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// The header of the section contains a coarse index that maps function address 402b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// to the page (4096 byte block) containing the unwind info for that function. 403b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 404b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 405b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik#define UNWIND_SECTION_VERSION 1 406b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzikstruct unwind_info_section_header 407b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik{ 408b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik uint32_t version; // UNWIND_SECTION_VERSION 409b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik uint32_t commonEncodingsArraySectionOffset; 410b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik uint32_t commonEncodingsArrayCount; 411b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik uint32_t personalityArraySectionOffset; 412b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik uint32_t personalityArrayCount; 413b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik uint32_t indexSectionOffset; 414b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik uint32_t indexCount; 415b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik // compact_unwind_encoding_t[] 416b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik // uintptr_t personalities[] 417b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik // unwind_info_section_header_index_entry[] 418b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik // unwind_info_section_header_lsda_index_entry[] 419b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik}; 420b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 421b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzikstruct unwind_info_section_header_index_entry 422b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik{ 423b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik uint32_t functionOffset; 424b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik uint32_t secondLevelPagesSectionOffset; // section offset to start of regular or compress page 425b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik uint32_t lsdaIndexArraySectionOffset; // section offset to start of lsda_index array for this range 426b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik}; 427b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 428b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzikstruct unwind_info_section_header_lsda_index_entry 429b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik{ 430b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik uint32_t functionOffset; 431b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik uint32_t lsdaOffset; 432b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik}; 433b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 434b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 435b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// There are two kinds of second level index pages: regular and compressed. 436b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// A compressed page can hold up to 1021 entries, but it cannot be used 437b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// if too many different encoding types are used. The regular page holds 438b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 511 entries. 439b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik// 440b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 441b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzikstruct unwind_info_regular_second_level_entry 442b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik{ 443b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik uint32_t functionOffset; 444b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik compact_unwind_encoding_t encoding; 445b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik}; 446b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 447b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik#define UNWIND_SECOND_LEVEL_REGULAR 2 448b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzikstruct unwind_info_regular_second_level_page_header 449b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik{ 450b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik uint32_t kind; // UNWIND_SECOND_LEVEL_REGULAR 451b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik uint16_t entryPageOffset; 452b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik uint16_t entryCount; 453b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik // entry array 454b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik}; 455b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 456b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik#define UNWIND_SECOND_LEVEL_COMPRESSED 3 457b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzikstruct unwind_info_compressed_second_level_page_header 458b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik{ 459b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik uint32_t kind; // UNWIND_SECOND_LEVEL_COMPRESSED 460b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik uint16_t entryPageOffset; 461b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik uint16_t entryCount; 462b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik uint16_t encodingsPageOffset; 463b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik uint16_t encodingsCount; 464b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik // 32-bit entry array 465b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik // encodings array 466b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik}; 467b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 468b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik#define UNWIND_INFO_COMPRESSED_ENTRY_FUNC_OFFSET(entry) (entry & 0x00FFFFFF) 469b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik#define UNWIND_INFO_COMPRESSED_ENTRY_ENCODING_INDEX(entry) ((entry >> 24) & 0xFF) 470b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 471b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 472b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 473b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik#endif 474b78da9875b6e35187b5d584746c78faaf3230a3dNick Kledzik 475