Re-commit the changes from r282565 that I had to back out because of
a linux bot test failure. That one is fixed; hopefully there won't
be any others turned up this time.
The eh_frame augmentation code wasn't working right after the
reorg/rewrite of the classes. It works correctly now for the one
test that was failing - but we'll see what the test bots come up
with.
<rdar://problem/28509178>
llvm-svn: 282659
diff --git a/lldb/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.cpp b/lldb/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.cpp
new file mode 100644
index 0000000..1384cf1
--- /dev/null
+++ b/lldb/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.cpp
@@ -0,0 +1,1112 @@
+//===-- x86AssemblyInspectionEngine.cpp -------------------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "x86AssemblyInspectionEngine.h"
+
+#include "llvm-c/Disassembler.h"
+
+#include "lldb/Core/Address.h"
+#include "lldb/Symbol/UnwindPlan.h"
+#include "lldb/Target/RegisterContext.h"
+#include "lldb/Target/UnwindAssembly.h"
+
+using namespace lldb_private;
+using namespace lldb;
+
+x86AssemblyInspectionEngine::x86AssemblyInspectionEngine(const ArchSpec &arch)
+ : m_cur_insn(nullptr), m_machine_ip_regnum(LLDB_INVALID_REGNUM),
+ m_machine_sp_regnum(LLDB_INVALID_REGNUM),
+ m_machine_fp_regnum(LLDB_INVALID_REGNUM),
+ m_lldb_ip_regnum(LLDB_INVALID_REGNUM),
+ m_lldb_sp_regnum(LLDB_INVALID_REGNUM),
+ m_lldb_fp_regnum(LLDB_INVALID_REGNUM),
+
+ m_reg_map(), m_arch(arch), m_cpu(k_cpu_unspecified), m_wordsize(-1),
+ m_register_map_initialized(false), m_disasm_context() {
+ m_disasm_context = ::LLVMCreateDisasm("x86_64-apple-macosx", nullptr,
+ /*TagType=*/1, nullptr, nullptr);
+ // ::LLVMCreateDisasm(arch.GetTriple().getTriple().c_str(), nullptr,
+ // /*TagType=*/1, nullptr, nullptr);
+}
+
+x86AssemblyInspectionEngine::~x86AssemblyInspectionEngine() {
+ ::LLVMDisasmDispose(m_disasm_context);
+}
+
+void x86AssemblyInspectionEngine::Initialize(RegisterContextSP ®_ctx) {
+ m_cpu = k_cpu_unspecified;
+ m_wordsize = -1;
+ m_register_map_initialized = false;
+
+ const llvm::Triple::ArchType cpu = m_arch.GetMachine();
+ if (cpu == llvm::Triple::x86)
+ m_cpu = k_i386;
+ else if (cpu == llvm::Triple::x86_64)
+ m_cpu = k_x86_64;
+
+ if (m_cpu == k_cpu_unspecified)
+ return;
+
+ if (reg_ctx.get() == nullptr)
+ return;
+
+ if (m_cpu == k_i386) {
+ m_machine_ip_regnum = k_machine_eip;
+ m_machine_sp_regnum = k_machine_esp;
+ m_machine_fp_regnum = k_machine_ebp;
+ m_wordsize = 4;
+
+ struct lldb_reg_info reginfo;
+ reginfo.name = "eax";
+ m_reg_map[k_machine_eax] = reginfo;
+ reginfo.name = "edx";
+ m_reg_map[k_machine_edx] = reginfo;
+ reginfo.name = "esp";
+ m_reg_map[k_machine_esp] = reginfo;
+ reginfo.name = "esi";
+ m_reg_map[k_machine_esi] = reginfo;
+ reginfo.name = "eip";
+ m_reg_map[k_machine_eip] = reginfo;
+ reginfo.name = "ecx";
+ m_reg_map[k_machine_ecx] = reginfo;
+ reginfo.name = "ebx";
+ m_reg_map[k_machine_ebx] = reginfo;
+ reginfo.name = "ebp";
+ m_reg_map[k_machine_ebp] = reginfo;
+ reginfo.name = "edi";
+ m_reg_map[k_machine_edi] = reginfo;
+ } else {
+ m_machine_ip_regnum = k_machine_rip;
+ m_machine_sp_regnum = k_machine_rsp;
+ m_machine_fp_regnum = k_machine_rbp;
+ m_wordsize = 8;
+
+ struct lldb_reg_info reginfo;
+ reginfo.name = "rax";
+ m_reg_map[k_machine_rax] = reginfo;
+ reginfo.name = "rdx";
+ m_reg_map[k_machine_rdx] = reginfo;
+ reginfo.name = "rsp";
+ m_reg_map[k_machine_rsp] = reginfo;
+ reginfo.name = "rsi";
+ m_reg_map[k_machine_rsi] = reginfo;
+ reginfo.name = "r8";
+ m_reg_map[k_machine_r8] = reginfo;
+ reginfo.name = "r10";
+ m_reg_map[k_machine_r10] = reginfo;
+ reginfo.name = "r12";
+ m_reg_map[k_machine_r12] = reginfo;
+ reginfo.name = "r14";
+ m_reg_map[k_machine_r14] = reginfo;
+ reginfo.name = "rip";
+ m_reg_map[k_machine_rip] = reginfo;
+ reginfo.name = "rcx";
+ m_reg_map[k_machine_rcx] = reginfo;
+ reginfo.name = "rbx";
+ m_reg_map[k_machine_rbx] = reginfo;
+ reginfo.name = "rbp";
+ m_reg_map[k_machine_rbp] = reginfo;
+ reginfo.name = "rdi";
+ m_reg_map[k_machine_rdi] = reginfo;
+ reginfo.name = "r9";
+ m_reg_map[k_machine_r9] = reginfo;
+ reginfo.name = "r11";
+ m_reg_map[k_machine_r11] = reginfo;
+ reginfo.name = "r13";
+ m_reg_map[k_machine_r13] = reginfo;
+ reginfo.name = "r15";
+ m_reg_map[k_machine_r15] = reginfo;
+ }
+
+ for (MachineRegnumToNameAndLLDBRegnum::iterator it = m_reg_map.begin();
+ it != m_reg_map.end(); ++it) {
+ const RegisterInfo *ri = reg_ctx->GetRegisterInfoByName(it->second.name);
+ if (ri)
+ it->second.lldb_regnum = ri->kinds[eRegisterKindLLDB];
+ }
+
+ uint32_t lldb_regno;
+ if (machine_regno_to_lldb_regno(m_machine_sp_regnum, lldb_regno))
+ m_lldb_sp_regnum = lldb_regno;
+ if (machine_regno_to_lldb_regno(m_machine_fp_regnum, lldb_regno))
+ m_lldb_fp_regnum = lldb_regno;
+ if (machine_regno_to_lldb_regno(m_machine_ip_regnum, lldb_regno))
+ m_lldb_ip_regnum = lldb_regno;
+
+ m_register_map_initialized = true;
+}
+
+void x86AssemblyInspectionEngine::Initialize(
+ std::vector<lldb_reg_info> ®_info) {
+ m_cpu = k_cpu_unspecified;
+ m_wordsize = -1;
+ m_register_map_initialized = false;
+
+ const llvm::Triple::ArchType cpu = m_arch.GetMachine();
+ if (cpu == llvm::Triple::x86)
+ m_cpu = k_i386;
+ else if (cpu == llvm::Triple::x86_64)
+ m_cpu = k_x86_64;
+
+ if (m_cpu == k_cpu_unspecified)
+ return;
+
+ if (m_cpu == k_i386) {
+ m_machine_ip_regnum = k_machine_eip;
+ m_machine_sp_regnum = k_machine_esp;
+ m_machine_fp_regnum = k_machine_ebp;
+ m_wordsize = 4;
+
+ struct lldb_reg_info reginfo;
+ reginfo.name = "eax";
+ m_reg_map[k_machine_eax] = reginfo;
+ reginfo.name = "edx";
+ m_reg_map[k_machine_edx] = reginfo;
+ reginfo.name = "esp";
+ m_reg_map[k_machine_esp] = reginfo;
+ reginfo.name = "esi";
+ m_reg_map[k_machine_esi] = reginfo;
+ reginfo.name = "eip";
+ m_reg_map[k_machine_eip] = reginfo;
+ reginfo.name = "ecx";
+ m_reg_map[k_machine_ecx] = reginfo;
+ reginfo.name = "ebx";
+ m_reg_map[k_machine_ebx] = reginfo;
+ reginfo.name = "ebp";
+ m_reg_map[k_machine_ebp] = reginfo;
+ reginfo.name = "edi";
+ m_reg_map[k_machine_edi] = reginfo;
+ } else {
+ m_machine_ip_regnum = k_machine_rip;
+ m_machine_sp_regnum = k_machine_rsp;
+ m_machine_fp_regnum = k_machine_rbp;
+ m_wordsize = 8;
+
+ struct lldb_reg_info reginfo;
+ reginfo.name = "rax";
+ m_reg_map[k_machine_rax] = reginfo;
+ reginfo.name = "rdx";
+ m_reg_map[k_machine_rdx] = reginfo;
+ reginfo.name = "rsp";
+ m_reg_map[k_machine_rsp] = reginfo;
+ reginfo.name = "rsi";
+ m_reg_map[k_machine_rsi] = reginfo;
+ reginfo.name = "r8";
+ m_reg_map[k_machine_r8] = reginfo;
+ reginfo.name = "r10";
+ m_reg_map[k_machine_r10] = reginfo;
+ reginfo.name = "r12";
+ m_reg_map[k_machine_r12] = reginfo;
+ reginfo.name = "r14";
+ m_reg_map[k_machine_r14] = reginfo;
+ reginfo.name = "rip";
+ m_reg_map[k_machine_rip] = reginfo;
+ reginfo.name = "rcx";
+ m_reg_map[k_machine_rcx] = reginfo;
+ reginfo.name = "rbx";
+ m_reg_map[k_machine_rbx] = reginfo;
+ reginfo.name = "rbp";
+ m_reg_map[k_machine_rbp] = reginfo;
+ reginfo.name = "rdi";
+ m_reg_map[k_machine_rdi] = reginfo;
+ reginfo.name = "r9";
+ m_reg_map[k_machine_r9] = reginfo;
+ reginfo.name = "r11";
+ m_reg_map[k_machine_r11] = reginfo;
+ reginfo.name = "r13";
+ m_reg_map[k_machine_r13] = reginfo;
+ reginfo.name = "r15";
+ m_reg_map[k_machine_r15] = reginfo;
+ }
+
+ for (MachineRegnumToNameAndLLDBRegnum::iterator it = m_reg_map.begin();
+ it != m_reg_map.end(); ++it) {
+ for (size_t i = 0; i < reg_info.size(); ++i) {
+ if (::strcmp(reg_info[i].name, it->second.name) == 0) {
+ it->second.lldb_regnum = reg_info[i].lldb_regnum;
+ break;
+ }
+ }
+ }
+
+ uint32_t lldb_regno;
+ if (machine_regno_to_lldb_regno(m_machine_sp_regnum, lldb_regno))
+ m_lldb_sp_regnum = lldb_regno;
+ if (machine_regno_to_lldb_regno(m_machine_fp_regnum, lldb_regno))
+ m_lldb_fp_regnum = lldb_regno;
+ if (machine_regno_to_lldb_regno(m_machine_ip_regnum, lldb_regno))
+ m_lldb_ip_regnum = lldb_regno;
+
+ m_register_map_initialized = true;
+}
+
+// This function expects an x86 native register number (i.e. the bits stripped
+// out of the
+// actual instruction), not an lldb register number.
+//
+// FIXME: This is ABI dependent, it shouldn't be hardcoded here.
+
+bool x86AssemblyInspectionEngine::nonvolatile_reg_p(int machine_regno) {
+ if (m_cpu == k_i386) {
+ switch (machine_regno) {
+ case k_machine_ebx:
+ case k_machine_ebp: // not actually a nonvolatile but often treated as such
+ // by convention
+ case k_machine_esi:
+ case k_machine_edi:
+ case k_machine_esp:
+ return true;
+ default:
+ return false;
+ }
+ }
+ if (m_cpu == k_x86_64) {
+ switch (machine_regno) {
+ case k_machine_rbx:
+ case k_machine_rsp:
+ case k_machine_rbp: // not actually a nonvolatile but often treated as such
+ // by convention
+ case k_machine_r12:
+ case k_machine_r13:
+ case k_machine_r14:
+ case k_machine_r15:
+ return true;
+ default:
+ return false;
+ }
+ }
+ return false;
+}
+
+// Macro to detect if this is a REX mode prefix byte.
+#define REX_W_PREFIX_P(opcode) (((opcode) & (~0x5)) == 0x48)
+
+// The high bit which should be added to the source register number (the "R"
+// bit)
+#define REX_W_SRCREG(opcode) (((opcode)&0x4) >> 2)
+
+// The high bit which should be added to the destination register number (the
+// "B" bit)
+#define REX_W_DSTREG(opcode) ((opcode)&0x1)
+
+// pushq %rbp [0x55]
+bool x86AssemblyInspectionEngine::push_rbp_pattern_p() {
+ uint8_t *p = m_cur_insn;
+ if (*p == 0x55)
+ return true;
+ return false;
+}
+
+// pushq $0 ; the first instruction in start() [0x6a 0x00]
+bool x86AssemblyInspectionEngine::push_0_pattern_p() {
+ uint8_t *p = m_cur_insn;
+ if (*p == 0x6a && *(p + 1) == 0x0)
+ return true;
+ return false;
+}
+
+// pushq $0
+// pushl $0
+bool x86AssemblyInspectionEngine::push_imm_pattern_p() {
+ uint8_t *p = m_cur_insn;
+ if (*p == 0x68 || *p == 0x6a)
+ return true;
+ return false;
+}
+
+// movq %rsp, %rbp [0x48 0x8b 0xec] or [0x48 0x89 0xe5]
+// movl %esp, %ebp [0x8b 0xec] or [0x89 0xe5]
+bool x86AssemblyInspectionEngine::mov_rsp_rbp_pattern_p() {
+ uint8_t *p = m_cur_insn;
+ if (m_wordsize == 8 && *p == 0x48)
+ p++;
+ if (*(p) == 0x8b && *(p + 1) == 0xec)
+ return true;
+ if (*(p) == 0x89 && *(p + 1) == 0xe5)
+ return true;
+ return false;
+}
+
+// subq $0x20, %rsp
+bool x86AssemblyInspectionEngine::sub_rsp_pattern_p(int &amount) {
+ uint8_t *p = m_cur_insn;
+ if (m_wordsize == 8 && *p == 0x48)
+ p++;
+ // 8-bit immediate operand
+ if (*p == 0x83 && *(p + 1) == 0xec) {
+ amount = (int8_t) * (p + 2);
+ return true;
+ }
+ // 32-bit immediate operand
+ if (*p == 0x81 && *(p + 1) == 0xec) {
+ amount = (int32_t)extract_4(p + 2);
+ return true;
+ }
+ return false;
+}
+
+// addq $0x20, %rsp
+bool x86AssemblyInspectionEngine::add_rsp_pattern_p(int &amount) {
+ uint8_t *p = m_cur_insn;
+ if (m_wordsize == 8 && *p == 0x48)
+ p++;
+ // 8-bit immediate operand
+ if (*p == 0x83 && *(p + 1) == 0xc4) {
+ amount = (int8_t) * (p + 2);
+ return true;
+ }
+ // 32-bit immediate operand
+ if (*p == 0x81 && *(p + 1) == 0xc4) {
+ amount = (int32_t)extract_4(p + 2);
+ return true;
+ }
+ return false;
+}
+
+// lea esp, [esp - 0x28]
+// lea esp, [esp + 0x28]
+bool x86AssemblyInspectionEngine::lea_rsp_pattern_p(int &amount) {
+ uint8_t *p = m_cur_insn;
+ if (m_wordsize == 8 && *p == 0x48)
+ p++;
+
+ // Check opcode
+ if (*p != 0x8d)
+ return false;
+
+ // 8 bit displacement
+ if (*(p + 1) == 0x64 && (*(p + 2) & 0x3f) == 0x24) {
+ amount = (int8_t) * (p + 3);
+ return true;
+ }
+
+ // 32 bit displacement
+ if (*(p + 1) == 0xa4 && (*(p + 2) & 0x3f) == 0x24) {
+ amount = (int32_t)extract_4(p + 3);
+ return true;
+ }
+
+ return false;
+}
+
+// pushq %rbx
+// pushl %ebx
+bool x86AssemblyInspectionEngine::push_reg_p(int ®no) {
+ uint8_t *p = m_cur_insn;
+ int regno_prefix_bit = 0;
+ // If we have a rex prefix byte, check to see if a B bit is set
+ if (m_wordsize == 8 && *p == 0x41) {
+ regno_prefix_bit = 1 << 3;
+ p++;
+ }
+ if (*p >= 0x50 && *p <= 0x57) {
+ regno = (*p - 0x50) | regno_prefix_bit;
+ return true;
+ }
+ return false;
+}
+
+// popq %rbx
+// popl %ebx
+bool x86AssemblyInspectionEngine::pop_reg_p(int ®no) {
+ uint8_t *p = m_cur_insn;
+ int regno_prefix_bit = 0;
+ // If we have a rex prefix byte, check to see if a B bit is set
+ if (m_wordsize == 8 && *p == 0x41) {
+ regno_prefix_bit = 1 << 3;
+ p++;
+ }
+ if (*p >= 0x58 && *p <= 0x5f) {
+ regno = (*p - 0x58) | regno_prefix_bit;
+ return true;
+ }
+ return false;
+}
+
+// popq %rbp [0x5d]
+// popl %ebp [0x5d]
+bool x86AssemblyInspectionEngine::pop_rbp_pattern_p() {
+ uint8_t *p = m_cur_insn;
+ return (*p == 0x5d);
+}
+
+// leave [0xc9]
+bool x86AssemblyInspectionEngine::leave_pattern_p() {
+ uint8_t *p = m_cur_insn;
+ return (*p == 0xc9);
+}
+
+// call $0 [0xe8 0x0 0x0 0x0 0x0]
+bool x86AssemblyInspectionEngine::call_next_insn_pattern_p() {
+ uint8_t *p = m_cur_insn;
+ return (*p == 0xe8) && (*(p + 1) == 0x0) && (*(p + 2) == 0x0) &&
+ (*(p + 3) == 0x0) && (*(p + 4) == 0x0);
+}
+
+// Look for an instruction sequence storing a nonvolatile register
+// on to the stack frame.
+
+// movq %rax, -0x10(%rbp) [0x48 0x89 0x45 0xf0]
+// movl %eax, -0xc(%ebp) [0x89 0x45 0xf4]
+
+// The offset value returned in rbp_offset will be positive --
+// but it must be subtraced from the frame base register to get
+// the actual location. The positive value returned for the offset
+// is a convention used elsewhere for CFA offsets et al.
+
+bool x86AssemblyInspectionEngine::mov_reg_to_local_stack_frame_p(
+ int ®no, int &rbp_offset) {
+ uint8_t *p = m_cur_insn;
+ int src_reg_prefix_bit = 0;
+ int target_reg_prefix_bit = 0;
+
+ if (m_wordsize == 8 && REX_W_PREFIX_P(*p)) {
+ src_reg_prefix_bit = REX_W_SRCREG(*p) << 3;
+ target_reg_prefix_bit = REX_W_DSTREG(*p) << 3;
+ if (target_reg_prefix_bit == 1) {
+ // rbp/ebp don't need a prefix bit - we know this isn't the
+ // reg we care about.
+ return false;
+ }
+ p++;
+ }
+
+ if (*p == 0x89) {
+ /* Mask off the 3-5 bits which indicate the destination register
+ if this is a ModR/M byte. */
+ int opcode_destreg_masked_out = *(p + 1) & (~0x38);
+
+ /* Is this a ModR/M byte with Mod bits 01 and R/M bits 101
+ and three bits between them, e.g. 01nnn101
+ We're looking for a destination of ebp-disp8 or ebp-disp32. */
+ int immsize;
+ if (opcode_destreg_masked_out == 0x45)
+ immsize = 2;
+ else if (opcode_destreg_masked_out == 0x85)
+ immsize = 4;
+ else
+ return false;
+
+ int offset = 0;
+ if (immsize == 2)
+ offset = (int8_t) * (p + 2);
+ if (immsize == 4)
+ offset = (uint32_t)extract_4(p + 2);
+ if (offset > 0)
+ return false;
+
+ regno = ((*(p + 1) >> 3) & 0x7) | src_reg_prefix_bit;
+ rbp_offset = offset > 0 ? offset : -offset;
+ return true;
+ }
+ return false;
+}
+
+// ret [0xc9] or [0xc2 imm8] or [0xca imm8]
+bool x86AssemblyInspectionEngine::ret_pattern_p() {
+ uint8_t *p = m_cur_insn;
+ if (*p == 0xc9 || *p == 0xc2 || *p == 0xca || *p == 0xc3)
+ return true;
+ return false;
+}
+
+uint32_t x86AssemblyInspectionEngine::extract_4(uint8_t *b) {
+ uint32_t v = 0;
+ for (int i = 3; i >= 0; i--)
+ v = (v << 8) | b[i];
+ return v;
+}
+
+bool x86AssemblyInspectionEngine::instruction_length(uint8_t *insn_p,
+ int &length) {
+
+ const uint32_t max_op_byte_size = m_arch.GetMaximumOpcodeByteSize();
+ llvm::SmallVector<uint8_t, 32> opcode_data;
+ opcode_data.resize(max_op_byte_size);
+
+ char out_string[512];
+ const size_t inst_size =
+ ::LLVMDisasmInstruction(m_disasm_context, insn_p, max_op_byte_size, 0,
+ out_string, sizeof(out_string));
+
+ length = inst_size;
+ return true;
+}
+
+bool x86AssemblyInspectionEngine::machine_regno_to_lldb_regno(
+ int machine_regno, uint32_t &lldb_regno) {
+ MachineRegnumToNameAndLLDBRegnum::iterator it = m_reg_map.find(machine_regno);
+ if (it != m_reg_map.end()) {
+ lldb_regno = it->second.lldb_regnum;
+ return true;
+ }
+ return false;
+ return false;
+}
+
+bool x86AssemblyInspectionEngine::GetNonCallSiteUnwindPlanFromAssembly(
+ uint8_t *data, size_t size, AddressRange &func_range,
+ UnwindPlan &unwind_plan) {
+ unwind_plan.Clear();
+
+ if (data == nullptr || size == 0)
+ return false;
+
+ if (m_register_map_initialized == false)
+ return false;
+
+ addr_t current_func_text_offset = 0;
+ int current_sp_bytes_offset_from_cfa = 0;
+ UnwindPlan::Row::RegisterLocation initial_regloc;
+ UnwindPlan::RowSP row(new UnwindPlan::Row);
+
+ unwind_plan.SetPlanValidAddressRange(func_range);
+ unwind_plan.SetRegisterKind(eRegisterKindLLDB);
+
+ // At the start of the function, find the CFA by adding wordsize to the SP
+ // register
+ row->SetOffset(current_func_text_offset);
+ row->GetCFAValue().SetIsRegisterPlusOffset(m_lldb_sp_regnum, m_wordsize);
+
+ // caller's stack pointer value before the call insn is the CFA address
+ initial_regloc.SetIsCFAPlusOffset(0);
+ row->SetRegisterInfo(m_lldb_sp_regnum, initial_regloc);
+
+ // saved instruction pointer can be found at CFA - wordsize.
+ current_sp_bytes_offset_from_cfa = m_wordsize;
+ initial_regloc.SetAtCFAPlusOffset(-current_sp_bytes_offset_from_cfa);
+ row->SetRegisterInfo(m_lldb_ip_regnum, initial_regloc);
+
+ unwind_plan.AppendRow(row);
+
+ // Allocate a new Row, populate it with the existing Row contents.
+ UnwindPlan::Row *newrow = new UnwindPlan::Row;
+ *newrow = *row.get();
+ row.reset(newrow);
+
+ // Track which registers have been saved so far in the prologue.
+ // If we see another push of that register, it's not part of the prologue.
+ // The register numbers used here are the machine register #'s
+ // (i386_register_numbers, x86_64_register_numbers).
+ std::vector<bool> saved_registers(32, false);
+
+ // Once the prologue has completed we'll save a copy of the unwind
+ // instructions
+ // If there is an epilogue in the middle of the function, after that epilogue
+ // we'll reinstate
+ // the unwind setup -- we assume that some code path jumps over the
+ // mid-function epilogue
+
+ UnwindPlan::RowSP prologue_completed_row; // copy of prologue row of CFI
+ int prologue_completed_sp_bytes_offset_from_cfa; // The sp value before the
+ // epilogue started executed
+ std::vector<bool> prologue_completed_saved_registers;
+
+ while (current_func_text_offset < size) {
+ int stack_offset, insn_len;
+ int machine_regno; // register numbers masked directly out of instructions
+ uint32_t lldb_regno; // register numbers in lldb's eRegisterKindLLDB
+ // numbering scheme
+
+ bool in_epilogue = false; // we're in the middle of an epilogue sequence
+ bool row_updated = false; // The UnwindPlan::Row 'row' has been updated
+
+ m_cur_insn = data + current_func_text_offset;
+ if (!instruction_length(m_cur_insn, insn_len) || insn_len == 0 ||
+ insn_len > kMaxInstructionByteSize) {
+ // An unrecognized/junk instruction
+ break;
+ }
+
+ if (push_rbp_pattern_p()) {
+ current_sp_bytes_offset_from_cfa += m_wordsize;
+ row->GetCFAValue().SetOffset(current_sp_bytes_offset_from_cfa);
+ UnwindPlan::Row::RegisterLocation regloc;
+ regloc.SetAtCFAPlusOffset(-row->GetCFAValue().GetOffset());
+ row->SetRegisterInfo(m_lldb_fp_regnum, regloc);
+ saved_registers[m_machine_fp_regnum] = true;
+ row_updated = true;
+ }
+
+ else if (mov_rsp_rbp_pattern_p()) {
+ row->GetCFAValue().SetIsRegisterPlusOffset(
+ m_lldb_fp_regnum, row->GetCFAValue().GetOffset());
+ row_updated = true;
+ }
+
+ // This is the start() function (or a pthread equivalent), it starts with a
+ // pushl $0x0 which puts the
+ // saved pc value of 0 on the stack. In this case we want to pretend we
+ // didn't see a stack movement at all --
+ // normally the saved pc value is already on the stack by the time the
+ // function starts executing.
+ else if (push_0_pattern_p()) {
+ }
+
+ else if (push_reg_p(machine_regno)) {
+ current_sp_bytes_offset_from_cfa += m_wordsize;
+ // the PUSH instruction has moved the stack pointer - if the CFA is set in
+ // terms of the stack pointer,
+ // we need to add a new row of instructions.
+ if (row->GetCFAValue().GetRegisterNumber() == m_lldb_sp_regnum) {
+ row->GetCFAValue().SetOffset(current_sp_bytes_offset_from_cfa);
+ row_updated = true;
+ }
+ // record where non-volatile (callee-saved, spilled) registers are saved
+ // on the stack
+ if (nonvolatile_reg_p(machine_regno) &&
+ machine_regno_to_lldb_regno(machine_regno, lldb_regno) &&
+ saved_registers[machine_regno] == false) {
+ UnwindPlan::Row::RegisterLocation regloc;
+ regloc.SetAtCFAPlusOffset(-current_sp_bytes_offset_from_cfa);
+ row->SetRegisterInfo(lldb_regno, regloc);
+ saved_registers[machine_regno] = true;
+ row_updated = true;
+ }
+ }
+
+ else if (pop_reg_p(machine_regno)) {
+ current_sp_bytes_offset_from_cfa -= m_wordsize;
+
+ if (nonvolatile_reg_p(machine_regno) &&
+ machine_regno_to_lldb_regno(machine_regno, lldb_regno) &&
+ saved_registers[machine_regno] == true) {
+ saved_registers[machine_regno] = false;
+ row->RemoveRegisterInfo(lldb_regno);
+
+ if (machine_regno == (int)m_machine_fp_regnum) {
+ row->GetCFAValue().SetIsRegisterPlusOffset(
+ m_lldb_sp_regnum, row->GetCFAValue().GetOffset());
+ }
+
+ in_epilogue = true;
+ row_updated = true;
+ }
+
+ // the POP instruction has moved the stack pointer - if the CFA is set in
+ // terms of the stack pointer,
+ // we need to add a new row of instructions.
+ if (row->GetCFAValue().GetRegisterNumber() == m_lldb_sp_regnum) {
+ row->GetCFAValue().SetIsRegisterPlusOffset(
+ m_lldb_sp_regnum, current_sp_bytes_offset_from_cfa);
+ row_updated = true;
+ }
+ }
+
+ // The LEAVE instruction moves the value from rbp into rsp and pops
+ // a value off the stack into rbp (restoring the caller's rbp value).
+ // It is the opposite of ENTER, or 'push rbp, mov rsp rbp'.
+ else if (leave_pattern_p()) {
+ // We're going to copy the value in rbp into rsp, so re-set the sp offset
+ // based on the CFAValue. Also, adjust it to recognize that we're popping
+ // the saved rbp value off the stack.
+ current_sp_bytes_offset_from_cfa = row->GetCFAValue().GetOffset();
+ current_sp_bytes_offset_from_cfa -= m_wordsize;
+ row->GetCFAValue().SetOffset(current_sp_bytes_offset_from_cfa);
+
+ // rbp is restored to the caller's value
+ saved_registers[m_machine_fp_regnum] = false;
+ row->RemoveRegisterInfo(m_lldb_fp_regnum);
+
+ // cfa is now in terms of rsp again.
+ row->GetCFAValue().SetIsRegisterPlusOffset(
+ m_lldb_sp_regnum, row->GetCFAValue().GetOffset());
+ row->GetCFAValue().SetOffset(current_sp_bytes_offset_from_cfa);
+
+ in_epilogue = true;
+ row_updated = true;
+ }
+
+ else if (mov_reg_to_local_stack_frame_p(machine_regno, stack_offset) &&
+ nonvolatile_reg_p(machine_regno) &&
+ machine_regno_to_lldb_regno(machine_regno, lldb_regno) &&
+ saved_registers[machine_regno] == false) {
+ saved_registers[machine_regno] = true;
+
+ UnwindPlan::Row::RegisterLocation regloc;
+
+ // stack_offset for 'movq %r15, -80(%rbp)' will be 80.
+ // In the Row, we want to express this as the offset from the CFA. If the
+ // frame base
+ // is rbp (like the above instruction), the CFA offset for rbp is probably
+ // 16. So we
+ // want to say that the value is stored at the CFA address - 96.
+ regloc.SetAtCFAPlusOffset(
+ -(stack_offset + row->GetCFAValue().GetOffset()));
+
+ row->SetRegisterInfo(lldb_regno, regloc);
+
+ row_updated = true;
+ }
+
+ else if (sub_rsp_pattern_p(stack_offset)) {
+ current_sp_bytes_offset_from_cfa += stack_offset;
+ if (row->GetCFAValue().GetRegisterNumber() == m_lldb_sp_regnum) {
+ row->GetCFAValue().SetOffset(current_sp_bytes_offset_from_cfa);
+ row_updated = true;
+ }
+ }
+
+ else if (add_rsp_pattern_p(stack_offset)) {
+ current_sp_bytes_offset_from_cfa -= stack_offset;
+ if (row->GetCFAValue().GetRegisterNumber() == m_lldb_sp_regnum) {
+ row->GetCFAValue().SetOffset(current_sp_bytes_offset_from_cfa);
+ row_updated = true;
+ }
+ in_epilogue = true;
+ }
+
+ else if (lea_rsp_pattern_p(stack_offset)) {
+ current_sp_bytes_offset_from_cfa -= stack_offset;
+ if (row->GetCFAValue().GetRegisterNumber() == m_lldb_sp_regnum) {
+ row->GetCFAValue().SetOffset(current_sp_bytes_offset_from_cfa);
+ row_updated = true;
+ }
+ if (stack_offset > 0)
+ in_epilogue = true;
+ }
+
+ else if (ret_pattern_p() && prologue_completed_row.get()) {
+ // Reinstate the saved prologue setup for any instructions
+ // that come after the ret instruction
+
+ UnwindPlan::Row *newrow = new UnwindPlan::Row;
+ *newrow = *prologue_completed_row.get();
+ row.reset(newrow);
+ current_sp_bytes_offset_from_cfa =
+ prologue_completed_sp_bytes_offset_from_cfa;
+
+ saved_registers.clear();
+ saved_registers.resize(prologue_completed_saved_registers.size(), false);
+ for (size_t i = 0; i < prologue_completed_saved_registers.size(); ++i) {
+ saved_registers[i] = prologue_completed_saved_registers[i];
+ }
+
+ in_epilogue = true;
+ row_updated = true;
+ }
+
+ // call next instruction
+ // call 0
+ // => pop %ebx
+ // This is used in i386 programs to get the PIC base address for finding
+ // global data
+ else if (call_next_insn_pattern_p()) {
+ current_sp_bytes_offset_from_cfa += m_wordsize;
+ if (row->GetCFAValue().GetRegisterNumber() == m_lldb_sp_regnum) {
+ row->GetCFAValue().SetOffset(current_sp_bytes_offset_from_cfa);
+ row_updated = true;
+ }
+ }
+
+ if (row_updated) {
+ if (current_func_text_offset + insn_len < size) {
+ row->SetOffset(current_func_text_offset + insn_len);
+ unwind_plan.AppendRow(row);
+ // Allocate a new Row, populate it with the existing Row contents.
+ newrow = new UnwindPlan::Row;
+ *newrow = *row.get();
+ row.reset(newrow);
+ }
+ }
+
+ if (in_epilogue == false && row_updated) {
+ // If we're not in an epilogue sequence, save the updated Row
+ UnwindPlan::Row *newrow = new UnwindPlan::Row;
+ *newrow = *row.get();
+ prologue_completed_row.reset(newrow);
+
+ prologue_completed_saved_registers.clear();
+ prologue_completed_saved_registers.resize(saved_registers.size(), false);
+ for (size_t i = 0; i < saved_registers.size(); ++i) {
+ prologue_completed_saved_registers[i] = saved_registers[i];
+ }
+ }
+
+ // We may change the sp value without adding a new Row necessarily -- keep
+ // track of it either way.
+ if (in_epilogue == false) {
+ prologue_completed_sp_bytes_offset_from_cfa =
+ current_sp_bytes_offset_from_cfa;
+ }
+
+ m_cur_insn = m_cur_insn + insn_len;
+ current_func_text_offset += insn_len;
+ }
+
+ unwind_plan.SetSourceName("assembly insn profiling");
+ unwind_plan.SetSourcedFromCompiler(eLazyBoolNo);
+ unwind_plan.SetUnwindPlanValidAtAllInstructions(eLazyBoolYes);
+
+ return true;
+}
+
+bool x86AssemblyInspectionEngine::AugmentUnwindPlanFromCallSite(
+ uint8_t *data, size_t size, AddressRange &func_range,
+ UnwindPlan &unwind_plan, RegisterContextSP ®_ctx) {
+ Address addr_start = func_range.GetBaseAddress();
+ if (!addr_start.IsValid())
+ return false;
+
+ // We either need a live RegisterContext, or we need the UnwindPlan to already
+ // be in the lldb register numbering scheme.
+ if (reg_ctx.get() == nullptr &&
+ unwind_plan.GetRegisterKind() != eRegisterKindLLDB)
+ return false;
+
+ // Is original unwind_plan valid?
+ // unwind_plan should have at least one row which is ABI-default (CFA register
+ // is sp),
+ // and another row in mid-function.
+ if (unwind_plan.GetRowCount() < 2)
+ return false;
+
+ UnwindPlan::RowSP first_row = unwind_plan.GetRowAtIndex(0);
+ if (first_row->GetOffset() != 0)
+ return false;
+ uint32_t cfa_reg = first_row->GetCFAValue().GetRegisterNumber();
+ if (unwind_plan.GetRegisterKind() != eRegisterKindLLDB) {
+ cfa_reg = reg_ctx->ConvertRegisterKindToRegisterNumber(
+ unwind_plan.GetRegisterKind(),
+ first_row->GetCFAValue().GetRegisterNumber());
+ }
+ if (cfa_reg != m_lldb_sp_regnum ||
+ first_row->GetCFAValue().GetOffset() != m_wordsize)
+ return false;
+
+ UnwindPlan::RowSP original_last_row = unwind_plan.GetRowForFunctionOffset(-1);
+
+ size_t offset = 0;
+ int row_id = 1;
+ bool unwind_plan_updated = false;
+ UnwindPlan::RowSP row(new UnwindPlan::Row(*first_row));
+ m_cur_insn = data + offset;
+
+ // After a mid-function epilogue we will need to re-insert the original unwind
+ // rules
+ // so unwinds work for the remainder of the function. These aren't common
+ // with clang/gcc
+ // on x86 but it is possible.
+ bool reinstate_unwind_state = false;
+
+ while (offset < size) {
+ m_cur_insn = data + offset;
+ int insn_len;
+ if (!instruction_length(m_cur_insn, insn_len) || insn_len == 0 ||
+ insn_len > kMaxInstructionByteSize) {
+ // An unrecognized/junk instruction.
+ break;
+ }
+
+ // Advance offsets.
+ offset += insn_len;
+ m_cur_insn = data + offset;
+
+ if (reinstate_unwind_state) {
+ // that was the last instruction of this function
+ if (offset >= size)
+ continue;
+
+ UnwindPlan::RowSP new_row(new UnwindPlan::Row());
+ *new_row = *original_last_row;
+ new_row->SetOffset(offset);
+ unwind_plan.AppendRow(new_row);
+ row.reset(new UnwindPlan::Row());
+ *row = *new_row;
+ reinstate_unwind_state = false;
+ unwind_plan_updated = true;
+ continue;
+ }
+
+ // If we already have one row for this instruction, we can continue.
+ while (row_id < unwind_plan.GetRowCount() &&
+ unwind_plan.GetRowAtIndex(row_id)->GetOffset() <= offset) {
+ row_id++;
+ }
+ UnwindPlan::RowSP original_row = unwind_plan.GetRowAtIndex(row_id - 1);
+ if (original_row->GetOffset() == offset) {
+ *row = *original_row;
+ continue;
+ }
+
+ if (row_id == 0) {
+ // If we are here, compiler didn't generate CFI for prologue.
+ // This won't happen to GCC or clang.
+ // In this case, bail out directly.
+ return false;
+ }
+
+ // Inspect the instruction to check if we need a new row for it.
+ cfa_reg = row->GetCFAValue().GetRegisterNumber();
+ if (unwind_plan.GetRegisterKind() != eRegisterKindLLDB) {
+ cfa_reg = reg_ctx->ConvertRegisterKindToRegisterNumber(
+ unwind_plan.GetRegisterKind(),
+ row->GetCFAValue().GetRegisterNumber());
+ }
+ if (cfa_reg == m_lldb_sp_regnum) {
+ // CFA register is sp.
+
+ // call next instruction
+ // call 0
+ // => pop %ebx
+ if (call_next_insn_pattern_p()) {
+ row->SetOffset(offset);
+ row->GetCFAValue().IncOffset(m_wordsize);
+
+ UnwindPlan::RowSP new_row(new UnwindPlan::Row(*row));
+ unwind_plan.InsertRow(new_row);
+ unwind_plan_updated = true;
+ continue;
+ }
+
+ // push/pop register
+ int regno;
+ if (push_reg_p(regno)) {
+ row->SetOffset(offset);
+ row->GetCFAValue().IncOffset(m_wordsize);
+
+ UnwindPlan::RowSP new_row(new UnwindPlan::Row(*row));
+ unwind_plan.InsertRow(new_row);
+ unwind_plan_updated = true;
+ continue;
+ }
+ if (pop_reg_p(regno)) {
+ // Technically, this might be a nonvolatile register recover in
+ // epilogue.
+ // We should reset RegisterInfo for the register.
+ // But in practice, previous rule for the register is still valid...
+ // So we ignore this case.
+
+ row->SetOffset(offset);
+ row->GetCFAValue().IncOffset(-m_wordsize);
+
+ UnwindPlan::RowSP new_row(new UnwindPlan::Row(*row));
+ unwind_plan.InsertRow(new_row);
+ unwind_plan_updated = true;
+ continue;
+ }
+
+ // push imm
+ if (push_imm_pattern_p()) {
+ row->SetOffset(offset);
+ row->GetCFAValue().IncOffset(m_wordsize);
+ UnwindPlan::RowSP new_row(new UnwindPlan::Row(*row));
+ unwind_plan.InsertRow(new_row);
+ unwind_plan_updated = true;
+ continue;
+ }
+
+ // add/sub %rsp/%esp
+ int amount;
+ if (add_rsp_pattern_p(amount)) {
+ row->SetOffset(offset);
+ row->GetCFAValue().IncOffset(-amount);
+
+ UnwindPlan::RowSP new_row(new UnwindPlan::Row(*row));
+ unwind_plan.InsertRow(new_row);
+ unwind_plan_updated = true;
+ continue;
+ }
+ if (sub_rsp_pattern_p(amount)) {
+ row->SetOffset(offset);
+ row->GetCFAValue().IncOffset(amount);
+
+ UnwindPlan::RowSP new_row(new UnwindPlan::Row(*row));
+ unwind_plan.InsertRow(new_row);
+ unwind_plan_updated = true;
+ continue;
+ }
+
+ // lea %rsp, [%rsp + $offset]
+ if (lea_rsp_pattern_p(amount)) {
+ row->SetOffset(offset);
+ row->GetCFAValue().IncOffset(-amount);
+
+ UnwindPlan::RowSP new_row(new UnwindPlan::Row(*row));
+ unwind_plan.InsertRow(new_row);
+ unwind_plan_updated = true;
+ continue;
+ }
+
+ if (ret_pattern_p()) {
+ reinstate_unwind_state = true;
+ continue;
+ }
+ } else if (cfa_reg == m_lldb_fp_regnum) {
+ // CFA register is fp.
+
+ // The only case we care about is epilogue:
+ // [0x5d] pop %rbp/%ebp
+ // => [0xc3] ret
+ if (pop_rbp_pattern_p() || leave_pattern_p()) {
+ offset += 1;
+ row->SetOffset(offset);
+ row->GetCFAValue().SetIsRegisterPlusOffset(
+ first_row->GetCFAValue().GetRegisterNumber(), m_wordsize);
+
+ UnwindPlan::RowSP new_row(new UnwindPlan::Row(*row));
+ unwind_plan.InsertRow(new_row);
+ unwind_plan_updated = true;
+ reinstate_unwind_state = true;
+ continue;
+ }
+ } else {
+ // CFA register is not sp or fp.
+
+ // This must be hand-written assembly.
+ // Just trust eh_frame and assume we have finished.
+ break;
+ }
+ }
+
+ unwind_plan.SetPlanValidAddressRange(func_range);
+ if (unwind_plan_updated) {
+ std::string unwind_plan_source(unwind_plan.GetSourceName().AsCString());
+ unwind_plan_source += " plus augmentation from assembly parsing";
+ unwind_plan.SetSourceName(unwind_plan_source.c_str());
+ unwind_plan.SetSourcedFromCompiler(eLazyBoolNo);
+ unwind_plan.SetUnwindPlanValidAtAllInstructions(eLazyBoolYes);
+ }
+ return true;
+}
+
+bool x86AssemblyInspectionEngine::FindFirstNonPrologueInstruction(
+ uint8_t *data, size_t size, size_t &offset) {
+ offset = 0;
+
+ if (m_register_map_initialized == false)
+ return false;
+
+ while (offset < size) {
+ int regno;
+ int insn_len;
+ int scratch;
+
+ m_cur_insn = data + offset;
+ if (!instruction_length(m_cur_insn, insn_len) ||
+ insn_len > kMaxInstructionByteSize || insn_len == 0) {
+ // An error parsing the instruction, i.e. probably data/garbage - stop
+ // scanning
+ break;
+ }
+
+ if (push_rbp_pattern_p() || mov_rsp_rbp_pattern_p() ||
+ sub_rsp_pattern_p(scratch) || push_reg_p(regno) ||
+ mov_reg_to_local_stack_frame_p(regno, scratch) ||
+ (lea_rsp_pattern_p(scratch) && offset == 0)) {
+ offset += insn_len;
+ continue;
+ }
+ //
+ // Unknown non-prologue instruction - stop scanning
+ break;
+ }
+
+ return true;
+}