Bug Summary

File:build/source/lldb/source/Expression/DWARFExpression.cpp
Warning:line 2216, column 9
Value stored to 'dwarf4_location_description_kind' is never read

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name DWARFExpression.cpp -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mframe-pointer=none -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/build/source/build-llvm/tools/clang/stage2-bins -resource-dir /usr/lib/llvm-17/lib/clang/17 -isystem /usr/include/libxml2 -I tools/lldb/source/Expression -I /build/source/lldb/source/Expression -I /build/source/lldb/include -I tools/lldb/include -I include -I /build/source/llvm/include -I /usr/include/python3.9 -I /build/source/clang/include -I tools/lldb/../clang/include -I /build/source/lldb/source -I tools/lldb/source -D HAVE_ROUND -D _DEBUG -D _GLIBCXX_ASSERTIONS -D _GNU_SOURCE -D _LIBCPP_ENABLE_ASSERTIONS -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -D _FORTIFY_SOURCE=2 -D NDEBUG -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/x86_64-linux-gnu/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/backward -internal-isystem /usr/lib/llvm-17/lib/clang/17/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -fmacro-prefix-map=/build/source/build-llvm/tools/clang/stage2-bins=build-llvm/tools/clang/stage2-bins -fmacro-prefix-map=/build/source/= -fcoverage-prefix-map=/build/source/build-llvm/tools/clang/stage2-bins=build-llvm/tools/clang/stage2-bins -fcoverage-prefix-map=/build/source/= -O2 -Wno-unused-command-line-argument -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wno-comment -Wno-misleading-indentation -Wno-deprecated-declarations -Wno-unknown-pragmas -Wno-strict-aliasing -Wno-stringop-truncation -std=c++17 -fdeprecated-macro -fdebug-compilation-dir=/build/source/build-llvm/tools/clang/stage2-bins -fdebug-prefix-map=/build/source/build-llvm/tools/clang/stage2-bins=build-llvm/tools/clang/stage2-bins -fdebug-prefix-map=/build/source/= -ferror-limit 19 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -fcolor-diagnostics -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2023-04-16-131055-16441-1 -x c++ /build/source/lldb/source/Expression/DWARFExpression.cpp
1//===-- DWARFExpression.cpp -----------------------------------------------===//
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#include "lldb/Expression/DWARFExpression.h"
10
11#include <cinttypes>
12
13#include <optional>
14#include <vector>
15
16#include "lldb/Core/Module.h"
17#include "lldb/Core/Value.h"
18#include "lldb/Core/dwarf.h"
19#include "lldb/Utility/DataEncoder.h"
20#include "lldb/Utility/LLDBLog.h"
21#include "lldb/Utility/Log.h"
22#include "lldb/Utility/RegisterValue.h"
23#include "lldb/Utility/Scalar.h"
24#include "lldb/Utility/StreamString.h"
25#include "lldb/Utility/VMRange.h"
26
27#include "lldb/Host/Host.h"
28#include "lldb/Utility/Endian.h"
29
30#include "lldb/Symbol/Function.h"
31
32#include "lldb/Target/ABI.h"
33#include "lldb/Target/ExecutionContext.h"
34#include "lldb/Target/Process.h"
35#include "lldb/Target/RegisterContext.h"
36#include "lldb/Target/StackFrame.h"
37#include "lldb/Target/StackID.h"
38#include "lldb/Target/Target.h"
39#include "lldb/Target/Thread.h"
40#include "llvm/DebugInfo/DWARF/DWARFDebugLoc.h"
41#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
42
43#include "Plugins/SymbolFile/DWARF/DWARFUnit.h"
44
45using namespace lldb;
46using namespace lldb_private;
47using namespace lldb_private::dwarf;
48
49// DWARFExpression constructor
50DWARFExpression::DWARFExpression() : m_data() {}
51
52DWARFExpression::DWARFExpression(const DataExtractor &data) : m_data(data) {}
53
54// Destructor
55DWARFExpression::~DWARFExpression() = default;
56
57bool DWARFExpression::IsValid() const { return m_data.GetByteSize() > 0; }
58
59void DWARFExpression::UpdateValue(uint64_t const_value,
60 lldb::offset_t const_value_byte_size,
61 uint8_t addr_byte_size) {
62 if (!const_value_byte_size)
63 return;
64
65 m_data.SetData(
66 DataBufferSP(new DataBufferHeap(&const_value, const_value_byte_size)));
67 m_data.SetByteOrder(endian::InlHostByteOrder());
68 m_data.SetAddressByteSize(addr_byte_size);
69}
70
71void DWARFExpression::DumpLocation(Stream *s, lldb::DescriptionLevel level,
72 ABI *abi) const {
73 auto *MCRegInfo = abi ? &abi->GetMCRegisterInfo() : nullptr;
74 auto GetRegName = [&MCRegInfo](uint64_t DwarfRegNum,
75 bool IsEH) -> llvm::StringRef {
76 if (!MCRegInfo)
77 return {};
78 if (std::optional<unsigned> LLVMRegNum =
79 MCRegInfo->getLLVMRegNum(DwarfRegNum, IsEH))
80 if (const char *RegName = MCRegInfo->getName(*LLVMRegNum))
81 return llvm::StringRef(RegName);
82 return {};
83 };
84 llvm::DIDumpOptions DumpOpts;
85 DumpOpts.GetNameForDWARFReg = GetRegName;
86 llvm::DWARFExpression(m_data.GetAsLLVM(), m_data.GetAddressByteSize())
87 .print(s->AsRawOstream(), DumpOpts, nullptr);
88}
89
90RegisterKind DWARFExpression::GetRegisterKind() const { return m_reg_kind; }
91
92void DWARFExpression::SetRegisterKind(RegisterKind reg_kind) {
93 m_reg_kind = reg_kind;
94}
95
96
97static bool ReadRegisterValueAsScalar(RegisterContext *reg_ctx,
98 lldb::RegisterKind reg_kind,
99 uint32_t reg_num, Status *error_ptr,
100 Value &value) {
101 if (reg_ctx == nullptr) {
102 if (error_ptr)
103 error_ptr->SetErrorString("No register context in frame.\n");
104 } else {
105 uint32_t native_reg =
106 reg_ctx->ConvertRegisterKindToRegisterNumber(reg_kind, reg_num);
107 if (native_reg == LLDB_INVALID_REGNUM(4294967295U)) {
108 if (error_ptr)
109 error_ptr->SetErrorStringWithFormat("Unable to convert register "
110 "kind=%u reg_num=%u to a native "
111 "register number.\n",
112 reg_kind, reg_num);
113 } else {
114 const RegisterInfo *reg_info =
115 reg_ctx->GetRegisterInfoAtIndex(native_reg);
116 RegisterValue reg_value;
117 if (reg_ctx->ReadRegister(reg_info, reg_value)) {
118 if (reg_value.GetScalarValue(value.GetScalar())) {
119 value.SetValueType(Value::ValueType::Scalar);
120 value.SetContext(Value::ContextType::RegisterInfo,
121 const_cast<RegisterInfo *>(reg_info));
122 if (error_ptr)
123 error_ptr->Clear();
124 return true;
125 } else {
126 // If we get this error, then we need to implement a value buffer in
127 // the dwarf expression evaluation function...
128 if (error_ptr)
129 error_ptr->SetErrorStringWithFormat(
130 "register %s can't be converted to a scalar value",
131 reg_info->name);
132 }
133 } else {
134 if (error_ptr)
135 error_ptr->SetErrorStringWithFormat("register %s is not available",
136 reg_info->name);
137 }
138 }
139 }
140 return false;
141}
142
143/// Return the length in bytes of the set of operands for \p op. No guarantees
144/// are made on the state of \p data after this call.
145static offset_t GetOpcodeDataSize(const DataExtractor &data,
146 const lldb::offset_t data_offset,
147 const uint8_t op, const DWARFUnit *dwarf_cu) {
148 lldb::offset_t offset = data_offset;
149 switch (op) {
150 case DW_OP_addr:
151 case DW_OP_call_ref: // 0x9a 1 address sized offset of DIE (DWARF3)
152 return data.GetAddressByteSize();
153
154 // Opcodes with no arguments
155 case DW_OP_deref: // 0x06
156 case DW_OP_dup: // 0x12
157 case DW_OP_drop: // 0x13
158 case DW_OP_over: // 0x14
159 case DW_OP_swap: // 0x16
160 case DW_OP_rot: // 0x17
161 case DW_OP_xderef: // 0x18
162 case DW_OP_abs: // 0x19
163 case DW_OP_and: // 0x1a
164 case DW_OP_div: // 0x1b
165 case DW_OP_minus: // 0x1c
166 case DW_OP_mod: // 0x1d
167 case DW_OP_mul: // 0x1e
168 case DW_OP_neg: // 0x1f
169 case DW_OP_not: // 0x20
170 case DW_OP_or: // 0x21
171 case DW_OP_plus: // 0x22
172 case DW_OP_shl: // 0x24
173 case DW_OP_shr: // 0x25
174 case DW_OP_shra: // 0x26
175 case DW_OP_xor: // 0x27
176 case DW_OP_eq: // 0x29
177 case DW_OP_ge: // 0x2a
178 case DW_OP_gt: // 0x2b
179 case DW_OP_le: // 0x2c
180 case DW_OP_lt: // 0x2d
181 case DW_OP_ne: // 0x2e
182 case DW_OP_lit0: // 0x30
183 case DW_OP_lit1: // 0x31
184 case DW_OP_lit2: // 0x32
185 case DW_OP_lit3: // 0x33
186 case DW_OP_lit4: // 0x34
187 case DW_OP_lit5: // 0x35
188 case DW_OP_lit6: // 0x36
189 case DW_OP_lit7: // 0x37
190 case DW_OP_lit8: // 0x38
191 case DW_OP_lit9: // 0x39
192 case DW_OP_lit10: // 0x3A
193 case DW_OP_lit11: // 0x3B
194 case DW_OP_lit12: // 0x3C
195 case DW_OP_lit13: // 0x3D
196 case DW_OP_lit14: // 0x3E
197 case DW_OP_lit15: // 0x3F
198 case DW_OP_lit16: // 0x40
199 case DW_OP_lit17: // 0x41
200 case DW_OP_lit18: // 0x42
201 case DW_OP_lit19: // 0x43
202 case DW_OP_lit20: // 0x44
203 case DW_OP_lit21: // 0x45
204 case DW_OP_lit22: // 0x46
205 case DW_OP_lit23: // 0x47
206 case DW_OP_lit24: // 0x48
207 case DW_OP_lit25: // 0x49
208 case DW_OP_lit26: // 0x4A
209 case DW_OP_lit27: // 0x4B
210 case DW_OP_lit28: // 0x4C
211 case DW_OP_lit29: // 0x4D
212 case DW_OP_lit30: // 0x4E
213 case DW_OP_lit31: // 0x4f
214 case DW_OP_reg0: // 0x50
215 case DW_OP_reg1: // 0x51
216 case DW_OP_reg2: // 0x52
217 case DW_OP_reg3: // 0x53
218 case DW_OP_reg4: // 0x54
219 case DW_OP_reg5: // 0x55
220 case DW_OP_reg6: // 0x56
221 case DW_OP_reg7: // 0x57
222 case DW_OP_reg8: // 0x58
223 case DW_OP_reg9: // 0x59
224 case DW_OP_reg10: // 0x5A
225 case DW_OP_reg11: // 0x5B
226 case DW_OP_reg12: // 0x5C
227 case DW_OP_reg13: // 0x5D
228 case DW_OP_reg14: // 0x5E
229 case DW_OP_reg15: // 0x5F
230 case DW_OP_reg16: // 0x60
231 case DW_OP_reg17: // 0x61
232 case DW_OP_reg18: // 0x62
233 case DW_OP_reg19: // 0x63
234 case DW_OP_reg20: // 0x64
235 case DW_OP_reg21: // 0x65
236 case DW_OP_reg22: // 0x66
237 case DW_OP_reg23: // 0x67
238 case DW_OP_reg24: // 0x68
239 case DW_OP_reg25: // 0x69
240 case DW_OP_reg26: // 0x6A
241 case DW_OP_reg27: // 0x6B
242 case DW_OP_reg28: // 0x6C
243 case DW_OP_reg29: // 0x6D
244 case DW_OP_reg30: // 0x6E
245 case DW_OP_reg31: // 0x6F
246 case DW_OP_nop: // 0x96
247 case DW_OP_push_object_address: // 0x97 DWARF3
248 case DW_OP_form_tls_address: // 0x9b DWARF3
249 case DW_OP_call_frame_cfa: // 0x9c DWARF3
250 case DW_OP_stack_value: // 0x9f DWARF4
251 case DW_OP_GNU_push_tls_address: // 0xe0 GNU extension
252 return 0;
253
254 // Opcodes with a single 1 byte arguments
255 case DW_OP_const1u: // 0x08 1 1-byte constant
256 case DW_OP_const1s: // 0x09 1 1-byte constant
257 case DW_OP_pick: // 0x15 1 1-byte stack index
258 case DW_OP_deref_size: // 0x94 1 1-byte size of data retrieved
259 case DW_OP_xderef_size: // 0x95 1 1-byte size of data retrieved
260 return 1;
261
262 // Opcodes with a single 2 byte arguments
263 case DW_OP_const2u: // 0x0a 1 2-byte constant
264 case DW_OP_const2s: // 0x0b 1 2-byte constant
265 case DW_OP_skip: // 0x2f 1 signed 2-byte constant
266 case DW_OP_bra: // 0x28 1 signed 2-byte constant
267 case DW_OP_call2: // 0x98 1 2-byte offset of DIE (DWARF3)
268 return 2;
269
270 // Opcodes with a single 4 byte arguments
271 case DW_OP_const4u: // 0x0c 1 4-byte constant
272 case DW_OP_const4s: // 0x0d 1 4-byte constant
273 case DW_OP_call4: // 0x99 1 4-byte offset of DIE (DWARF3)
274 return 4;
275
276 // Opcodes with a single 8 byte arguments
277 case DW_OP_const8u: // 0x0e 1 8-byte constant
278 case DW_OP_const8s: // 0x0f 1 8-byte constant
279 return 8;
280
281 // All opcodes that have a single ULEB (signed or unsigned) argument
282 case DW_OP_addrx: // 0xa1 1 ULEB128 index
283 case DW_OP_constu: // 0x10 1 ULEB128 constant
284 case DW_OP_consts: // 0x11 1 SLEB128 constant
285 case DW_OP_plus_uconst: // 0x23 1 ULEB128 addend
286 case DW_OP_breg0: // 0x70 1 ULEB128 register
287 case DW_OP_breg1: // 0x71 1 ULEB128 register
288 case DW_OP_breg2: // 0x72 1 ULEB128 register
289 case DW_OP_breg3: // 0x73 1 ULEB128 register
290 case DW_OP_breg4: // 0x74 1 ULEB128 register
291 case DW_OP_breg5: // 0x75 1 ULEB128 register
292 case DW_OP_breg6: // 0x76 1 ULEB128 register
293 case DW_OP_breg7: // 0x77 1 ULEB128 register
294 case DW_OP_breg8: // 0x78 1 ULEB128 register
295 case DW_OP_breg9: // 0x79 1 ULEB128 register
296 case DW_OP_breg10: // 0x7a 1 ULEB128 register
297 case DW_OP_breg11: // 0x7b 1 ULEB128 register
298 case DW_OP_breg12: // 0x7c 1 ULEB128 register
299 case DW_OP_breg13: // 0x7d 1 ULEB128 register
300 case DW_OP_breg14: // 0x7e 1 ULEB128 register
301 case DW_OP_breg15: // 0x7f 1 ULEB128 register
302 case DW_OP_breg16: // 0x80 1 ULEB128 register
303 case DW_OP_breg17: // 0x81 1 ULEB128 register
304 case DW_OP_breg18: // 0x82 1 ULEB128 register
305 case DW_OP_breg19: // 0x83 1 ULEB128 register
306 case DW_OP_breg20: // 0x84 1 ULEB128 register
307 case DW_OP_breg21: // 0x85 1 ULEB128 register
308 case DW_OP_breg22: // 0x86 1 ULEB128 register
309 case DW_OP_breg23: // 0x87 1 ULEB128 register
310 case DW_OP_breg24: // 0x88 1 ULEB128 register
311 case DW_OP_breg25: // 0x89 1 ULEB128 register
312 case DW_OP_breg26: // 0x8a 1 ULEB128 register
313 case DW_OP_breg27: // 0x8b 1 ULEB128 register
314 case DW_OP_breg28: // 0x8c 1 ULEB128 register
315 case DW_OP_breg29: // 0x8d 1 ULEB128 register
316 case DW_OP_breg30: // 0x8e 1 ULEB128 register
317 case DW_OP_breg31: // 0x8f 1 ULEB128 register
318 case DW_OP_regx: // 0x90 1 ULEB128 register
319 case DW_OP_fbreg: // 0x91 1 SLEB128 offset
320 case DW_OP_piece: // 0x93 1 ULEB128 size of piece addressed
321 case DW_OP_GNU_addr_index: // 0xfb 1 ULEB128 index
322 case DW_OP_GNU_const_index: // 0xfc 1 ULEB128 index
323 data.Skip_LEB128(&offset);
324 return offset - data_offset;
325
326 // All opcodes that have a 2 ULEB (signed or unsigned) arguments
327 case DW_OP_bregx: // 0x92 2 ULEB128 register followed by SLEB128 offset
328 case DW_OP_bit_piece: // 0x9d ULEB128 bit size, ULEB128 bit offset (DWARF3);
329 data.Skip_LEB128(&offset);
330 data.Skip_LEB128(&offset);
331 return offset - data_offset;
332
333 case DW_OP_implicit_value: // 0x9e ULEB128 size followed by block of that size
334 // (DWARF4)
335 {
336 uint64_t block_len = data.Skip_LEB128(&offset);
337 offset += block_len;
338 return offset - data_offset;
339 }
340
341 case DW_OP_GNU_entry_value:
342 case DW_OP_entry_value: // 0xa3 ULEB128 size + variable-length block
343 {
344 uint64_t subexpr_len = data.GetULEB128(&offset);
345 return (offset - data_offset) + subexpr_len;
346 }
347
348 default:
349 if (!dwarf_cu) {
350 return LLDB_INVALID_OFFSET(18446744073709551615UL);
351 }
352 return dwarf_cu->GetSymbolFileDWARF().GetVendorDWARFOpcodeSize(
353 data, data_offset, op);
354 }
355}
356
357lldb::addr_t DWARFExpression::GetLocation_DW_OP_addr(const DWARFUnit *dwarf_cu,
358 uint32_t op_addr_idx,
359 bool &error) const {
360 error = false;
361 lldb::offset_t offset = 0;
362 uint32_t curr_op_addr_idx = 0;
363 while (m_data.ValidOffset(offset)) {
364 const uint8_t op = m_data.GetU8(&offset);
365
366 if (op == DW_OP_addr) {
367 const lldb::addr_t op_file_addr = m_data.GetAddress(&offset);
368 if (curr_op_addr_idx == op_addr_idx)
369 return op_file_addr;
370 ++curr_op_addr_idx;
371 } else if (op == DW_OP_GNU_addr_index || op == DW_OP_addrx) {
372 uint64_t index = m_data.GetULEB128(&offset);
373 if (curr_op_addr_idx == op_addr_idx) {
374 if (!dwarf_cu) {
375 error = true;
376 break;
377 }
378
379 return dwarf_cu->ReadAddressFromDebugAddrSection(index);
380 }
381 ++curr_op_addr_idx;
382 } else {
383 const offset_t op_arg_size =
384 GetOpcodeDataSize(m_data, offset, op, dwarf_cu);
385 if (op_arg_size == LLDB_INVALID_OFFSET(18446744073709551615UL)) {
386 error = true;
387 break;
388 }
389 offset += op_arg_size;
390 }
391 }
392 return LLDB_INVALID_ADDRESS(18446744073709551615UL);
393}
394
395bool DWARFExpression::Update_DW_OP_addr(const DWARFUnit *dwarf_cu,
396 lldb::addr_t file_addr) {
397 lldb::offset_t offset = 0;
398 while (m_data.ValidOffset(offset)) {
399 const uint8_t op = m_data.GetU8(&offset);
400
401 if (op == DW_OP_addr) {
402 const uint32_t addr_byte_size = m_data.GetAddressByteSize();
403 // We have to make a copy of the data as we don't know if this data is
404 // from a read only memory mapped buffer, so we duplicate all of the data
405 // first, then modify it, and if all goes well, we then replace the data
406 // for this expression
407
408 // Make en encoder that contains a copy of the location expression data
409 // so we can write the address into the buffer using the correct byte
410 // order.
411 DataEncoder encoder(m_data.GetDataStart(), m_data.GetByteSize(),
412 m_data.GetByteOrder(), addr_byte_size);
413
414 // Replace the address in the new buffer
415 if (encoder.PutAddress(offset, file_addr) == UINT32_MAX(4294967295U))
416 return false;
417
418 // All went well, so now we can reset the data using a shared pointer to
419 // the heap data so "m_data" will now correctly manage the heap data.
420 m_data.SetData(encoder.GetDataBuffer());
421 return true;
422 } else {
423 const offset_t op_arg_size =
424 GetOpcodeDataSize(m_data, offset, op, dwarf_cu);
425 if (op_arg_size == LLDB_INVALID_OFFSET(18446744073709551615UL))
426 break;
427 offset += op_arg_size;
428 }
429 }
430 return false;
431}
432
433bool DWARFExpression::ContainsThreadLocalStorage(
434 const DWARFUnit *dwarf_cu) const {
435 lldb::offset_t offset = 0;
436 while (m_data.ValidOffset(offset)) {
437 const uint8_t op = m_data.GetU8(&offset);
438
439 if (op == DW_OP_form_tls_address || op == DW_OP_GNU_push_tls_address)
440 return true;
441 const offset_t op_arg_size =
442 GetOpcodeDataSize(m_data, offset, op, dwarf_cu);
443 if (op_arg_size == LLDB_INVALID_OFFSET(18446744073709551615UL))
444 return false;
445 offset += op_arg_size;
446 }
447 return false;
448}
449bool DWARFExpression::LinkThreadLocalStorage(
450 const DWARFUnit *dwarf_cu,
451 std::function<lldb::addr_t(lldb::addr_t file_addr)> const
452 &link_address_callback) {
453 const uint32_t addr_byte_size = m_data.GetAddressByteSize();
454 // We have to make a copy of the data as we don't know if this data is from a
455 // read only memory mapped buffer, so we duplicate all of the data first,
456 // then modify it, and if all goes well, we then replace the data for this
457 // expression.
458 // Make en encoder that contains a copy of the location expression data so we
459 // can write the address into the buffer using the correct byte order.
460 DataEncoder encoder(m_data.GetDataStart(), m_data.GetByteSize(),
461 m_data.GetByteOrder(), addr_byte_size);
462
463 lldb::offset_t offset = 0;
464 lldb::offset_t const_offset = 0;
465 lldb::addr_t const_value = 0;
466 size_t const_byte_size = 0;
467 while (m_data.ValidOffset(offset)) {
468 const uint8_t op = m_data.GetU8(&offset);
469
470 bool decoded_data = false;
471 switch (op) {
472 case DW_OP_const4u:
473 // Remember the const offset in case we later have a
474 // DW_OP_form_tls_address or DW_OP_GNU_push_tls_address
475 const_offset = offset;
476 const_value = m_data.GetU32(&offset);
477 decoded_data = true;
478 const_byte_size = 4;
479 break;
480
481 case DW_OP_const8u:
482 // Remember the const offset in case we later have a
483 // DW_OP_form_tls_address or DW_OP_GNU_push_tls_address
484 const_offset = offset;
485 const_value = m_data.GetU64(&offset);
486 decoded_data = true;
487 const_byte_size = 8;
488 break;
489
490 case DW_OP_form_tls_address:
491 case DW_OP_GNU_push_tls_address:
492 // DW_OP_form_tls_address and DW_OP_GNU_push_tls_address must be preceded
493 // by a file address on the stack. We assume that DW_OP_const4u or
494 // DW_OP_const8u is used for these values, and we check that the last
495 // opcode we got before either of these was DW_OP_const4u or
496 // DW_OP_const8u. If so, then we can link the value accordingly. For
497 // Darwin, the value in the DW_OP_const4u or DW_OP_const8u is the file
498 // address of a structure that contains a function pointer, the pthread
499 // key and the offset into the data pointed to by the pthread key. So we
500 // must link this address and also set the module of this expression to
501 // the new_module_sp so we can resolve the file address correctly
502 if (const_byte_size > 0) {
503 lldb::addr_t linked_file_addr = link_address_callback(const_value);
504 if (linked_file_addr == LLDB_INVALID_ADDRESS(18446744073709551615UL))
505 return false;
506 // Replace the address in the new buffer
507 if (encoder.PutUnsigned(const_offset, const_byte_size,
508 linked_file_addr) == UINT32_MAX(4294967295U))
509 return false;
510 }
511 break;
512
513 default:
514 const_offset = 0;
515 const_value = 0;
516 const_byte_size = 0;
517 break;
518 }
519
520 if (!decoded_data) {
521 const offset_t op_arg_size =
522 GetOpcodeDataSize(m_data, offset, op, dwarf_cu);
523 if (op_arg_size == LLDB_INVALID_OFFSET(18446744073709551615UL))
524 return false;
525 else
526 offset += op_arg_size;
527 }
528 }
529
530 m_data.SetData(encoder.GetDataBuffer());
531 return true;
532}
533
534static bool Evaluate_DW_OP_entry_value(std::vector<Value> &stack,
535 ExecutionContext *exe_ctx,
536 RegisterContext *reg_ctx,
537 const DataExtractor &opcodes,
538 lldb::offset_t &opcode_offset,
539 Status *error_ptr, Log *log) {
540 // DW_OP_entry_value(sub-expr) describes the location a variable had upon
541 // function entry: this variable location is presumed to be optimized out at
542 // the current PC value. The caller of the function may have call site
543 // information that describes an alternate location for the variable (e.g. a
544 // constant literal, or a spilled stack value) in the parent frame.
545 //
546 // Example (this is pseudo-code & pseudo-DWARF, but hopefully illustrative):
547 //
548 // void child(int &sink, int x) {
549 // ...
550 // /* "x" gets optimized out. */
551 //
552 // /* The location of "x" here is: DW_OP_entry_value($reg2). */
553 // ++sink;
554 // }
555 //
556 // void parent() {
557 // int sink;
558 //
559 // /*
560 // * The callsite information emitted here is:
561 // *
562 // * DW_TAG_call_site
563 // * DW_AT_return_pc ... (for "child(sink, 123);")
564 // * DW_TAG_call_site_parameter (for "sink")
565 // * DW_AT_location ($reg1)
566 // * DW_AT_call_value ($SP - 8)
567 // * DW_TAG_call_site_parameter (for "x")
568 // * DW_AT_location ($reg2)
569 // * DW_AT_call_value ($literal 123)
570 // *
571 // * DW_TAG_call_site
572 // * DW_AT_return_pc ... (for "child(sink, 456);")
573 // * ...
574 // */
575 // child(sink, 123);
576 // child(sink, 456);
577 // }
578 //
579 // When the program stops at "++sink" within `child`, the debugger determines
580 // the call site by analyzing the return address. Once the call site is found,
581 // the debugger determines which parameter is referenced by DW_OP_entry_value
582 // and evaluates the corresponding location for that parameter in `parent`.
583
584 // 1. Find the function which pushed the current frame onto the stack.
585 if ((!exe_ctx || !exe_ctx->HasTargetScope()) || !reg_ctx) {
586 LLDB_LOG(log, "Evaluate_DW_OP_entry_value: no exe/reg context")do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Format("lldb/source/Expression/DWARFExpression.cpp"
, __func__, "Evaluate_DW_OP_entry_value: no exe/reg context")
; } while (0)
;
587 return false;
588 }
589
590 StackFrame *current_frame = exe_ctx->GetFramePtr();
591 Thread *thread = exe_ctx->GetThreadPtr();
592 if (!current_frame || !thread) {
593 LLDB_LOG(log, "Evaluate_DW_OP_entry_value: no current frame/thread")do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Format("lldb/source/Expression/DWARFExpression.cpp"
, __func__, "Evaluate_DW_OP_entry_value: no current frame/thread"
); } while (0)
;
594 return false;
595 }
596
597 Target &target = exe_ctx->GetTargetRef();
598 StackFrameSP parent_frame = nullptr;
599 addr_t return_pc = LLDB_INVALID_ADDRESS(18446744073709551615UL);
600 uint32_t current_frame_idx = current_frame->GetFrameIndex();
601 uint32_t num_frames = thread->GetStackFrameCount();
602 for (uint32_t parent_frame_idx = current_frame_idx + 1;
603 parent_frame_idx < num_frames; ++parent_frame_idx) {
604 parent_frame = thread->GetStackFrameAtIndex(parent_frame_idx);
605 // Require a valid sequence of frames.
606 if (!parent_frame)
607 break;
608
609 // Record the first valid return address, even if this is an inlined frame,
610 // in order to look up the associated call edge in the first non-inlined
611 // parent frame.
612 if (return_pc == LLDB_INVALID_ADDRESS(18446744073709551615UL)) {
613 return_pc = parent_frame->GetFrameCodeAddress().GetLoadAddress(&target);
614 LLDB_LOG(log,do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Format("lldb/source/Expression/DWARFExpression.cpp"
, __func__, "Evaluate_DW_OP_entry_value: immediate ancestor with pc = {0:x}"
, return_pc); } while (0)
615 "Evaluate_DW_OP_entry_value: immediate ancestor with pc = {0:x}",do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Format("lldb/source/Expression/DWARFExpression.cpp"
, __func__, "Evaluate_DW_OP_entry_value: immediate ancestor with pc = {0:x}"
, return_pc); } while (0)
616 return_pc)do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Format("lldb/source/Expression/DWARFExpression.cpp"
, __func__, "Evaluate_DW_OP_entry_value: immediate ancestor with pc = {0:x}"
, return_pc); } while (0)
;
617 }
618
619 // If we've found an inlined frame, skip it (these have no call site
620 // parameters).
621 if (parent_frame->IsInlined())
622 continue;
623
624 // We've found the first non-inlined parent frame.
625 break;
626 }
627 if (!parent_frame || !parent_frame->GetRegisterContext()) {
628 LLDB_LOG(log, "Evaluate_DW_OP_entry_value: no parent frame with reg ctx")do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Format("lldb/source/Expression/DWARFExpression.cpp"
, __func__, "Evaluate_DW_OP_entry_value: no parent frame with reg ctx"
); } while (0)
;
629 return false;
630 }
631
632 Function *parent_func =
633 parent_frame->GetSymbolContext(eSymbolContextFunction).function;
634 if (!parent_func) {
635 LLDB_LOG(log, "Evaluate_DW_OP_entry_value: no parent function")do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Format("lldb/source/Expression/DWARFExpression.cpp"
, __func__, "Evaluate_DW_OP_entry_value: no parent function")
; } while (0)
;
636 return false;
637 }
638
639 // 2. Find the call edge in the parent function responsible for creating the
640 // current activation.
641 Function *current_func =
642 current_frame->GetSymbolContext(eSymbolContextFunction).function;
643 if (!current_func) {
644 LLDB_LOG(log, "Evaluate_DW_OP_entry_value: no current function")do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Format("lldb/source/Expression/DWARFExpression.cpp"
, __func__, "Evaluate_DW_OP_entry_value: no current function"
); } while (0)
;
645 return false;
646 }
647
648 CallEdge *call_edge = nullptr;
649 ModuleList &modlist = target.GetImages();
650 ExecutionContext parent_exe_ctx = *exe_ctx;
651 parent_exe_ctx.SetFrameSP(parent_frame);
652 if (!parent_frame->IsArtificial()) {
653 // If the parent frame is not artificial, the current activation may be
654 // produced by an ambiguous tail call. In this case, refuse to proceed.
655 call_edge = parent_func->GetCallEdgeForReturnAddress(return_pc, target);
656 if (!call_edge) {
657 LLDB_LOG(log,do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Format("lldb/source/Expression/DWARFExpression.cpp"
, __func__, "Evaluate_DW_OP_entry_value: no call edge for retn-pc = {0:x} "
"in parent frame {1}", return_pc, parent_func->GetName())
; } while (0)
658 "Evaluate_DW_OP_entry_value: no call edge for retn-pc = {0:x} "do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Format("lldb/source/Expression/DWARFExpression.cpp"
, __func__, "Evaluate_DW_OP_entry_value: no call edge for retn-pc = {0:x} "
"in parent frame {1}", return_pc, parent_func->GetName())
; } while (0)
659 "in parent frame {1}",do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Format("lldb/source/Expression/DWARFExpression.cpp"
, __func__, "Evaluate_DW_OP_entry_value: no call edge for retn-pc = {0:x} "
"in parent frame {1}", return_pc, parent_func->GetName())
; } while (0)
660 return_pc, parent_func->GetName())do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Format("lldb/source/Expression/DWARFExpression.cpp"
, __func__, "Evaluate_DW_OP_entry_value: no call edge for retn-pc = {0:x} "
"in parent frame {1}", return_pc, parent_func->GetName())
; } while (0)
;
661 return false;
662 }
663 Function *callee_func = call_edge->GetCallee(modlist, parent_exe_ctx);
664 if (callee_func != current_func) {
665 LLDB_LOG(log, "Evaluate_DW_OP_entry_value: ambiguous call sequence, "do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Format("lldb/source/Expression/DWARFExpression.cpp"
, __func__, "Evaluate_DW_OP_entry_value: ambiguous call sequence, "
"can't find real parent frame"); } while (0)
666 "can't find real parent frame")do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Format("lldb/source/Expression/DWARFExpression.cpp"
, __func__, "Evaluate_DW_OP_entry_value: ambiguous call sequence, "
"can't find real parent frame"); } while (0)
;
667 return false;
668 }
669 } else {
670 // The StackFrameList solver machinery has deduced that an unambiguous tail
671 // call sequence that produced the current activation. The first edge in
672 // the parent that points to the current function must be valid.
673 for (auto &edge : parent_func->GetTailCallingEdges()) {
674 if (edge->GetCallee(modlist, parent_exe_ctx) == current_func) {
675 call_edge = edge.get();
676 break;
677 }
678 }
679 }
680 if (!call_edge) {
681 LLDB_LOG(log, "Evaluate_DW_OP_entry_value: no unambiguous edge from parent "do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Format("lldb/source/Expression/DWARFExpression.cpp"
, __func__, "Evaluate_DW_OP_entry_value: no unambiguous edge from parent "
"to current function"); } while (0)
682 "to current function")do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Format("lldb/source/Expression/DWARFExpression.cpp"
, __func__, "Evaluate_DW_OP_entry_value: no unambiguous edge from parent "
"to current function"); } while (0)
;
683 return false;
684 }
685
686 // 3. Attempt to locate the DW_OP_entry_value expression in the set of
687 // available call site parameters. If found, evaluate the corresponding
688 // parameter in the context of the parent frame.
689 const uint32_t subexpr_len = opcodes.GetULEB128(&opcode_offset);
690 const void *subexpr_data = opcodes.GetData(&opcode_offset, subexpr_len);
691 if (!subexpr_data) {
692 LLDB_LOG(log, "Evaluate_DW_OP_entry_value: subexpr could not be read")do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Format("lldb/source/Expression/DWARFExpression.cpp"
, __func__, "Evaluate_DW_OP_entry_value: subexpr could not be read"
); } while (0)
;
693 return false;
694 }
695
696 const CallSiteParameter *matched_param = nullptr;
697 for (const CallSiteParameter &param : call_edge->GetCallSiteParameters()) {
698 DataExtractor param_subexpr_extractor;
699 if (!param.LocationInCallee.GetExpressionData(param_subexpr_extractor))
700 continue;
701 lldb::offset_t param_subexpr_offset = 0;
702 const void *param_subexpr_data =
703 param_subexpr_extractor.GetData(&param_subexpr_offset, subexpr_len);
704 if (!param_subexpr_data ||
705 param_subexpr_extractor.BytesLeft(param_subexpr_offset) != 0)
706 continue;
707
708 // At this point, the DW_OP_entry_value sub-expression and the callee-side
709 // expression in the call site parameter are known to have the same length.
710 // Check whether they are equal.
711 //
712 // Note that an equality check is sufficient: the contents of the
713 // DW_OP_entry_value subexpression are only used to identify the right call
714 // site parameter in the parent, and do not require any special handling.
715 if (memcmp(subexpr_data, param_subexpr_data, subexpr_len) == 0) {
716 matched_param = &param;
717 break;
718 }
719 }
720 if (!matched_param) {
721 LLDB_LOG(log,do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Format("lldb/source/Expression/DWARFExpression.cpp"
, __func__, "Evaluate_DW_OP_entry_value: no matching call site param found"
); } while (0)
722 "Evaluate_DW_OP_entry_value: no matching call site param found")do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Format("lldb/source/Expression/DWARFExpression.cpp"
, __func__, "Evaluate_DW_OP_entry_value: no matching call site param found"
); } while (0)
;
723 return false;
724 }
725
726 // TODO: Add support for DW_OP_push_object_address within a DW_OP_entry_value
727 // subexpresion whenever llvm does.
728 Value result;
729 const DWARFExpressionList &param_expr = matched_param->LocationInCaller;
730 if (!param_expr.Evaluate(&parent_exe_ctx,
731 parent_frame->GetRegisterContext().get(),
732 LLDB_INVALID_ADDRESS(18446744073709551615UL),
733 /*initial_value_ptr=*/nullptr,
734 /*object_address_ptr=*/nullptr, result, error_ptr)) {
735 LLDB_LOG(log,do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Format("lldb/source/Expression/DWARFExpression.cpp"
, __func__, "Evaluate_DW_OP_entry_value: call site param evaluation failed"
); } while (0)
736 "Evaluate_DW_OP_entry_value: call site param evaluation failed")do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Format("lldb/source/Expression/DWARFExpression.cpp"
, __func__, "Evaluate_DW_OP_entry_value: call site param evaluation failed"
); } while (0)
;
737 return false;
738 }
739
740 stack.push_back(result);
741 return true;
742}
743
744namespace {
745/// The location description kinds described by the DWARF v5
746/// specification. Composite locations are handled out-of-band and
747/// thus aren't part of the enum.
748enum LocationDescriptionKind {
749 Empty,
750 Memory,
751 Register,
752 Implicit
753 /* Composite*/
754};
755/// Adjust value's ValueType according to the kind of location description.
756void UpdateValueTypeFromLocationDescription(Log *log, const DWARFUnit *dwarf_cu,
757 LocationDescriptionKind kind,
758 Value *value = nullptr) {
759 // Note that this function is conflating DWARF expressions with
760 // DWARF location descriptions. Perhaps it would be better to define
761 // a wrapper for DWARFExpression::Eval() that deals with DWARF
762 // location descriptions (which consist of one or more DWARF
763 // expressions). But doing this would mean we'd also need factor the
764 // handling of DW_OP_(bit_)piece out of this function.
765 if (dwarf_cu && dwarf_cu->GetVersion() >= 4) {
766 const char *log_msg = "DWARF location description kind: %s";
767 switch (kind) {
768 case Empty:
769 LLDB_LOGF(log, log_msg, "Empty")do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf(log_msg, "Empty"); } while (0)
;
770 break;
771 case Memory:
772 LLDB_LOGF(log, log_msg, "Memory")do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf(log_msg, "Memory"); } while (0)
;
773 if (value->GetValueType() == Value::ValueType::Scalar)
774 value->SetValueType(Value::ValueType::LoadAddress);
775 break;
776 case Register:
777 LLDB_LOGF(log, log_msg, "Register")do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf(log_msg, "Register"); } while (0)
;
778 value->SetValueType(Value::ValueType::Scalar);
779 break;
780 case Implicit:
781 LLDB_LOGF(log, log_msg, "Implicit")do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf(log_msg, "Implicit"); } while (0)
;
782 if (value->GetValueType() == Value::ValueType::LoadAddress)
783 value->SetValueType(Value::ValueType::Scalar);
784 break;
785 }
786 }
787}
788} // namespace
789
790/// Helper function to move common code used to resolve a file address and turn
791/// into a load address.
792///
793/// \param exe_ctx Pointer to the execution context
794/// \param module_sp shared_ptr contains the module if we have one
795/// \param error_ptr pointer to Status object if we have one
796/// \param dw_op_type C-style string used to vary the error output
797/// \param file_addr the file address we are trying to resolve and turn into a
798/// load address
799/// \param so_addr out parameter, will be set to load address or section offset
800/// \param check_sectionoffset bool which determines if having a section offset
801/// but not a load address is considerd a success
802/// \returns std::optional containing the load address if resolving and getting
803/// the load address succeed or an empty Optinal otherwise. If
804/// check_sectionoffset is true we consider LLDB_INVALID_ADDRESS a
805/// success if so_addr.IsSectionOffset() is true.
806static std::optional<lldb::addr_t>
807ResolveLoadAddress(ExecutionContext *exe_ctx, lldb::ModuleSP &module_sp,
808 Status *error_ptr, const char *dw_op_type,
809 lldb::addr_t file_addr, Address &so_addr,
810 bool check_sectionoffset = false) {
811 if (!module_sp) {
812 if (error_ptr)
813 error_ptr->SetErrorStringWithFormat(
814 "need module to resolve file address for %s", dw_op_type);
815 return {};
816 }
817
818 if (!module_sp->ResolveFileAddress(file_addr, so_addr)) {
819 if (error_ptr)
820 error_ptr->SetErrorString("failed to resolve file address in module");
821 return {};
822 }
823
824 addr_t load_addr = so_addr.GetLoadAddress(exe_ctx->GetTargetPtr());
825
826 if (load_addr == LLDB_INVALID_ADDRESS(18446744073709551615UL) &&
827 (check_sectionoffset && !so_addr.IsSectionOffset())) {
828 if (error_ptr)
829 error_ptr->SetErrorString("failed to resolve load address");
830 return {};
831 }
832
833 return load_addr;
834}
835
836/// Helper function to move common code used to load sized data from a uint8_t
837/// buffer.
838///
839/// \param addr_bytes uint8_t buffer containg raw data
840/// \param size_addr_bytes how large is the underlying raw data
841/// \param byte_order what is the byter order of the underlyig data
842/// \param size How much of the underlying data we want to use
843/// \return The underlying data converted into a Scalar
844static Scalar DerefSizeExtractDataHelper(uint8_t *addr_bytes,
845 size_t size_addr_bytes,
846 ByteOrder byte_order, size_t size) {
847 DataExtractor addr_data(addr_bytes, size_addr_bytes, byte_order, size);
848
849 lldb::offset_t addr_data_offset = 0;
850 if (size <= 8)
851 return addr_data.GetMaxU64(&addr_data_offset, size);
852 else
853 return addr_data.GetAddress(&addr_data_offset);
854}
855
856bool DWARFExpression::Evaluate(
857 ExecutionContext *exe_ctx, RegisterContext *reg_ctx,
858 lldb::ModuleSP module_sp, const DataExtractor &opcodes,
859 const DWARFUnit *dwarf_cu, const lldb::RegisterKind reg_kind,
860 const Value *initial_value_ptr, const Value *object_address_ptr,
861 Value &result, Status *error_ptr) {
862
863 if (opcodes.GetByteSize() == 0) {
864 if (error_ptr)
865 error_ptr->SetErrorString(
866 "no location, value may have been optimized out");
867 return false;
868 }
869 std::vector<Value> stack;
870
871 Process *process = nullptr;
872 StackFrame *frame = nullptr;
873 Target *target = nullptr;
874
875 if (exe_ctx) {
876 process = exe_ctx->GetProcessPtr();
877 frame = exe_ctx->GetFramePtr();
878 target = exe_ctx->GetTargetPtr();
879 }
880 if (reg_ctx == nullptr && frame)
881 reg_ctx = frame->GetRegisterContext().get();
882
883 if (initial_value_ptr)
884 stack.push_back(*initial_value_ptr);
885
886 lldb::offset_t offset = 0;
887 Value tmp;
888 uint32_t reg_num;
889
890 /// Insertion point for evaluating multi-piece expression.
891 uint64_t op_piece_offset = 0;
892 Value pieces; // Used for DW_OP_piece
893
894 Log *log = GetLog(LLDBLog::Expressions);
895 // A generic type is "an integral type that has the size of an address and an
896 // unspecified signedness". For now, just use the signedness of the operand.
897 // TODO: Implement a real typed stack, and store the genericness of the value
898 // there.
899 auto to_generic = [&](auto v) {
900 bool is_signed = std::is_signed<decltype(v)>::value;
901 return Scalar(llvm::APSInt(
902 llvm::APInt(8 * opcodes.GetAddressByteSize(), v, is_signed),
903 !is_signed));
904 };
905
906 // The default kind is a memory location. This is updated by any
907 // operation that changes this, such as DW_OP_stack_value, and reset
908 // by composition operations like DW_OP_piece.
909 LocationDescriptionKind dwarf4_location_description_kind = Memory;
910
911 while (opcodes.ValidOffset(offset)) {
912 const lldb::offset_t op_offset = offset;
913 const uint8_t op = opcodes.GetU8(&offset);
914
915 if (log && log->GetVerbose()) {
916 size_t count = stack.size();
917 LLDB_LOGF(log, "Stack before operation has %" PRIu64 " values:",do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("Stack before operation has %" "l" "u"
" values:", (uint64_t)count); } while (0)
918 (uint64_t)count)do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("Stack before operation has %" "l" "u"
" values:", (uint64_t)count); } while (0)
;
919 for (size_t i = 0; i < count; ++i) {
920 StreamString new_value;
921 new_value.Printf("[%" PRIu64"l" "u" "]", (uint64_t)i);
922 stack[i].Dump(&new_value);
923 LLDB_LOGF(log, " %s", new_value.GetData())do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf(" %s", new_value.GetData()); } while
(0)
;
924 }
925 LLDB_LOGF(log, "0x%8.8" PRIx64 ": %s", op_offset,do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("0x%8.8" "l" "x" ": %s", op_offset, DW_OP_value_to_name
(op)); } while (0)
926 DW_OP_value_to_name(op))do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("0x%8.8" "l" "x" ": %s", op_offset, DW_OP_value_to_name
(op)); } while (0)
;
927 }
928
929 switch (op) {
930 // The DW_OP_addr operation has a single operand that encodes a machine
931 // address and whose size is the size of an address on the target machine.
932 case DW_OP_addr:
933 stack.push_back(Scalar(opcodes.GetAddress(&offset)));
934 if (target &&
935 target->GetArchitecture().GetCore() == ArchSpec::eCore_wasm32) {
936 // wasm file sections aren't mapped into memory, therefore addresses can
937 // never point into a file section and are always LoadAddresses.
938 stack.back().SetValueType(Value::ValueType::LoadAddress);
939 } else {
940 stack.back().SetValueType(Value::ValueType::FileAddress);
941 }
942 break;
943
944 // The DW_OP_addr_sect_offset4 is used for any location expressions in
945 // shared libraries that have a location like:
946 // DW_OP_addr(0x1000)
947 // If this address resides in a shared library, then this virtual address
948 // won't make sense when it is evaluated in the context of a running
949 // process where shared libraries have been slid. To account for this, this
950 // new address type where we can store the section pointer and a 4 byte
951 // offset.
952 // case DW_OP_addr_sect_offset4:
953 // {
954 // result_type = eResultTypeFileAddress;
955 // lldb::Section *sect = (lldb::Section
956 // *)opcodes.GetMaxU64(&offset, sizeof(void *));
957 // lldb::addr_t sect_offset = opcodes.GetU32(&offset);
958 //
959 // Address so_addr (sect, sect_offset);
960 // lldb::addr_t load_addr = so_addr.GetLoadAddress();
961 // if (load_addr != LLDB_INVALID_ADDRESS)
962 // {
963 // // We successfully resolve a file address to a load
964 // // address.
965 // stack.push_back(load_addr);
966 // break;
967 // }
968 // else
969 // {
970 // // We were able
971 // if (error_ptr)
972 // error_ptr->SetErrorStringWithFormat ("Section %s in
973 // %s is not currently loaded.\n",
974 // sect->GetName().AsCString(),
975 // sect->GetModule()->GetFileSpec().GetFilename().AsCString());
976 // return false;
977 // }
978 // }
979 // break;
980
981 // OPCODE: DW_OP_deref
982 // OPERANDS: none
983 // DESCRIPTION: Pops the top stack entry and treats it as an address.
984 // The value retrieved from that address is pushed. The size of the data
985 // retrieved from the dereferenced address is the size of an address on the
986 // target machine.
987 case DW_OP_deref: {
988 if (stack.empty()) {
989 if (error_ptr)
990 error_ptr->SetErrorString("Expression stack empty for DW_OP_deref.");
991 return false;
992 }
993 Value::ValueType value_type = stack.back().GetValueType();
994 switch (value_type) {
995 case Value::ValueType::HostAddress: {
996 void *src = (void *)stack.back().GetScalar().ULongLong();
997 intptr_t ptr;
998 ::memcpy(&ptr, src, sizeof(void *));
999 stack.back().GetScalar() = ptr;
1000 stack.back().ClearContext();
1001 } break;
1002 case Value::ValueType::FileAddress: {
1003 auto file_addr = stack.back().GetScalar().ULongLong(
1004 LLDB_INVALID_ADDRESS(18446744073709551615UL));
1005
1006 Address so_addr;
1007 auto maybe_load_addr = ResolveLoadAddress(
1008 exe_ctx, module_sp, error_ptr, "DW_OP_deref", file_addr, so_addr);
1009
1010 if (!maybe_load_addr)
1011 return false;
1012
1013 stack.back().GetScalar() = *maybe_load_addr;
1014 // Fall through to load address promotion code below.
1015 }
1016 [[fallthrough]];
1017 case Value::ValueType::Scalar:
1018 // Promote Scalar to LoadAddress and fall through.
1019 stack.back().SetValueType(Value::ValueType::LoadAddress);
1020 [[fallthrough]];
1021 case Value::ValueType::LoadAddress:
1022 if (exe_ctx) {
1023 if (process) {
1024 lldb::addr_t pointer_addr =
1025 stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS(18446744073709551615UL));
1026 Status error;
1027 lldb::addr_t pointer_value =
1028 process->ReadPointerFromMemory(pointer_addr, error);
1029 if (pointer_value != LLDB_INVALID_ADDRESS(18446744073709551615UL)) {
1030 if (ABISP abi_sp = process->GetABI())
1031 pointer_value = abi_sp->FixCodeAddress(pointer_value);
1032 stack.back().GetScalar() = pointer_value;
1033 stack.back().ClearContext();
1034 } else {
1035 if (error_ptr)
1036 error_ptr->SetErrorStringWithFormat(
1037 "Failed to dereference pointer from 0x%" PRIx64"l" "x"
1038 " for DW_OP_deref: %s\n",
1039 pointer_addr, error.AsCString());
1040 return false;
1041 }
1042 } else {
1043 if (error_ptr)
1044 error_ptr->SetErrorString("NULL process for DW_OP_deref.\n");
1045 return false;
1046 }
1047 } else {
1048 if (error_ptr)
1049 error_ptr->SetErrorString(
1050 "NULL execution context for DW_OP_deref.\n");
1051 return false;
1052 }
1053 break;
1054
1055 case Value::ValueType::Invalid:
1056 if (error_ptr)
1057 error_ptr->SetErrorString("Invalid value type for DW_OP_deref.\n");
1058 return false;
1059 }
1060
1061 } break;
1062
1063 // OPCODE: DW_OP_deref_size
1064 // OPERANDS: 1
1065 // 1 - uint8_t that specifies the size of the data to dereference.
1066 // DESCRIPTION: Behaves like the DW_OP_deref operation: it pops the top
1067 // stack entry and treats it as an address. The value retrieved from that
1068 // address is pushed. In the DW_OP_deref_size operation, however, the size
1069 // in bytes of the data retrieved from the dereferenced address is
1070 // specified by the single operand. This operand is a 1-byte unsigned
1071 // integral constant whose value may not be larger than the size of an
1072 // address on the target machine. The data retrieved is zero extended to
1073 // the size of an address on the target machine before being pushed on the
1074 // expression stack.
1075 case DW_OP_deref_size: {
1076 if (stack.empty()) {
1077 if (error_ptr)
1078 error_ptr->SetErrorString(
1079 "Expression stack empty for DW_OP_deref_size.");
1080 return false;
1081 }
1082 uint8_t size = opcodes.GetU8(&offset);
1083 Value::ValueType value_type = stack.back().GetValueType();
1084 switch (value_type) {
1085 case Value::ValueType::HostAddress: {
1086 void *src = (void *)stack.back().GetScalar().ULongLong();
1087 intptr_t ptr;
1088 ::memcpy(&ptr, src, sizeof(void *));
1089 // I can't decide whether the size operand should apply to the bytes in
1090 // their
1091 // lldb-host endianness or the target endianness.. I doubt this'll ever
1092 // come up but I'll opt for assuming big endian regardless.
1093 switch (size) {
1094 case 1:
1095 ptr = ptr & 0xff;
1096 break;
1097 case 2:
1098 ptr = ptr & 0xffff;
1099 break;
1100 case 3:
1101 ptr = ptr & 0xffffff;
1102 break;
1103 case 4:
1104 ptr = ptr & 0xffffffff;
1105 break;
1106 // the casts are added to work around the case where intptr_t is a 32
1107 // bit quantity;
1108 // presumably we won't hit the 5..7 cases if (void*) is 32-bits in this
1109 // program.
1110 case 5:
1111 ptr = (intptr_t)ptr & 0xffffffffffULL;
1112 break;
1113 case 6:
1114 ptr = (intptr_t)ptr & 0xffffffffffffULL;
1115 break;
1116 case 7:
1117 ptr = (intptr_t)ptr & 0xffffffffffffffULL;
1118 break;
1119 default:
1120 break;
1121 }
1122 stack.back().GetScalar() = ptr;
1123 stack.back().ClearContext();
1124 } break;
1125 case Value::ValueType::FileAddress: {
1126 auto file_addr =
1127 stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS(18446744073709551615UL));
1128 Address so_addr;
1129 auto maybe_load_addr =
1130 ResolveLoadAddress(exe_ctx, module_sp, error_ptr,
1131 "DW_OP_deref_size", file_addr, so_addr,
1132 /*check_sectionoffset=*/true);
1133
1134 if (!maybe_load_addr)
1135 return false;
1136
1137 addr_t load_addr = *maybe_load_addr;
1138
1139 if (load_addr == LLDB_INVALID_ADDRESS(18446744073709551615UL) && so_addr.IsSectionOffset()) {
1140 uint8_t addr_bytes[8];
1141 Status error;
1142
1143 if (target &&
1144 target->ReadMemory(so_addr, &addr_bytes, size, error,
1145 /*force_live_memory=*/false) == size) {
1146 ObjectFile *objfile = module_sp->GetObjectFile();
1147
1148 stack.back().GetScalar() = DerefSizeExtractDataHelper(
1149 addr_bytes, size, objfile->GetByteOrder(), size);
1150 stack.back().ClearContext();
1151 break;
1152 } else {
1153 if (error_ptr)
1154 error_ptr->SetErrorStringWithFormat(
1155 "Failed to dereference pointer for for DW_OP_deref_size: "
1156 "%s\n",
1157 error.AsCString());
1158 return false;
1159 }
1160 }
1161 stack.back().GetScalar() = load_addr;
1162 // Fall through to load address promotion code below.
1163 }
1164
1165 [[fallthrough]];
1166 case Value::ValueType::Scalar:
1167 case Value::ValueType::LoadAddress:
1168 if (exe_ctx) {
1169 if (process) {
1170 lldb::addr_t pointer_addr =
1171 stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS(18446744073709551615UL));
1172 uint8_t addr_bytes[sizeof(lldb::addr_t)];
1173 Status error;
1174 if (process->ReadMemory(pointer_addr, &addr_bytes, size, error) ==
1175 size) {
1176
1177 stack.back().GetScalar() =
1178 DerefSizeExtractDataHelper(addr_bytes, sizeof(addr_bytes),
1179 process->GetByteOrder(), size);
1180 stack.back().ClearContext();
1181 } else {
1182 if (error_ptr)
1183 error_ptr->SetErrorStringWithFormat(
1184 "Failed to dereference pointer from 0x%" PRIx64"l" "x"
1185 " for DW_OP_deref: %s\n",
1186 pointer_addr, error.AsCString());
1187 return false;
1188 }
1189 } else {
1190 if (error_ptr)
1191 error_ptr->SetErrorString("NULL process for DW_OP_deref_size.\n");
1192 return false;
1193 }
1194 } else {
1195 if (error_ptr)
1196 error_ptr->SetErrorString(
1197 "NULL execution context for DW_OP_deref_size.\n");
1198 return false;
1199 }
1200 break;
1201
1202 case Value::ValueType::Invalid:
1203 if (error_ptr)
1204 error_ptr->SetErrorString("Invalid value for DW_OP_deref_size.\n");
1205 return false;
1206 }
1207
1208 } break;
1209
1210 // OPCODE: DW_OP_xderef_size
1211 // OPERANDS: 1
1212 // 1 - uint8_t that specifies the size of the data to dereference.
1213 // DESCRIPTION: Behaves like the DW_OP_xderef operation: the entry at
1214 // the top of the stack is treated as an address. The second stack entry is
1215 // treated as an "address space identifier" for those architectures that
1216 // support multiple address spaces. The top two stack elements are popped,
1217 // a data item is retrieved through an implementation-defined address
1218 // calculation and pushed as the new stack top. In the DW_OP_xderef_size
1219 // operation, however, the size in bytes of the data retrieved from the
1220 // dereferenced address is specified by the single operand. This operand is
1221 // a 1-byte unsigned integral constant whose value may not be larger than
1222 // the size of an address on the target machine. The data retrieved is zero
1223 // extended to the size of an address on the target machine before being
1224 // pushed on the expression stack.
1225 case DW_OP_xderef_size:
1226 if (error_ptr)
1227 error_ptr->SetErrorString("Unimplemented opcode: DW_OP_xderef_size.");
1228 return false;
1229 // OPCODE: DW_OP_xderef
1230 // OPERANDS: none
1231 // DESCRIPTION: Provides an extended dereference mechanism. The entry at
1232 // the top of the stack is treated as an address. The second stack entry is
1233 // treated as an "address space identifier" for those architectures that
1234 // support multiple address spaces. The top two stack elements are popped,
1235 // a data item is retrieved through an implementation-defined address
1236 // calculation and pushed as the new stack top. The size of the data
1237 // retrieved from the dereferenced address is the size of an address on the
1238 // target machine.
1239 case DW_OP_xderef:
1240 if (error_ptr)
1241 error_ptr->SetErrorString("Unimplemented opcode: DW_OP_xderef.");
1242 return false;
1243
1244 // All DW_OP_constXXX opcodes have a single operand as noted below:
1245 //
1246 // Opcode Operand 1
1247 // DW_OP_const1u 1-byte unsigned integer constant
1248 // DW_OP_const1s 1-byte signed integer constant
1249 // DW_OP_const2u 2-byte unsigned integer constant
1250 // DW_OP_const2s 2-byte signed integer constant
1251 // DW_OP_const4u 4-byte unsigned integer constant
1252 // DW_OP_const4s 4-byte signed integer constant
1253 // DW_OP_const8u 8-byte unsigned integer constant
1254 // DW_OP_const8s 8-byte signed integer constant
1255 // DW_OP_constu unsigned LEB128 integer constant
1256 // DW_OP_consts signed LEB128 integer constant
1257 case DW_OP_const1u:
1258 stack.push_back(to_generic(opcodes.GetU8(&offset)));
1259 break;
1260 case DW_OP_const1s:
1261 stack.push_back(to_generic((int8_t)opcodes.GetU8(&offset)));
1262 break;
1263 case DW_OP_const2u:
1264 stack.push_back(to_generic(opcodes.GetU16(&offset)));
1265 break;
1266 case DW_OP_const2s:
1267 stack.push_back(to_generic((int16_t)opcodes.GetU16(&offset)));
1268 break;
1269 case DW_OP_const4u:
1270 stack.push_back(to_generic(opcodes.GetU32(&offset)));
1271 break;
1272 case DW_OP_const4s:
1273 stack.push_back(to_generic((int32_t)opcodes.GetU32(&offset)));
1274 break;
1275 case DW_OP_const8u:
1276 stack.push_back(to_generic(opcodes.GetU64(&offset)));
1277 break;
1278 case DW_OP_const8s:
1279 stack.push_back(to_generic((int64_t)opcodes.GetU64(&offset)));
1280 break;
1281 // These should also use to_generic, but we can't do that due to a
1282 // producer-side bug in llvm. See llvm.org/pr48087.
1283 case DW_OP_constu:
1284 stack.push_back(Scalar(opcodes.GetULEB128(&offset)));
1285 break;
1286 case DW_OP_consts:
1287 stack.push_back(Scalar(opcodes.GetSLEB128(&offset)));
1288 break;
1289
1290 // OPCODE: DW_OP_dup
1291 // OPERANDS: none
1292 // DESCRIPTION: duplicates the value at the top of the stack
1293 case DW_OP_dup:
1294 if (stack.empty()) {
1295 if (error_ptr)
1296 error_ptr->SetErrorString("Expression stack empty for DW_OP_dup.");
1297 return false;
1298 } else
1299 stack.push_back(stack.back());
1300 break;
1301
1302 // OPCODE: DW_OP_drop
1303 // OPERANDS: none
1304 // DESCRIPTION: pops the value at the top of the stack
1305 case DW_OP_drop:
1306 if (stack.empty()) {
1307 if (error_ptr)
1308 error_ptr->SetErrorString("Expression stack empty for DW_OP_drop.");
1309 return false;
1310 } else
1311 stack.pop_back();
1312 break;
1313
1314 // OPCODE: DW_OP_over
1315 // OPERANDS: none
1316 // DESCRIPTION: Duplicates the entry currently second in the stack at
1317 // the top of the stack.
1318 case DW_OP_over:
1319 if (stack.size() < 2) {
1320 if (error_ptr)
1321 error_ptr->SetErrorString(
1322 "Expression stack needs at least 2 items for DW_OP_over.");
1323 return false;
1324 } else
1325 stack.push_back(stack[stack.size() - 2]);
1326 break;
1327
1328 // OPCODE: DW_OP_pick
1329 // OPERANDS: uint8_t index into the current stack
1330 // DESCRIPTION: The stack entry with the specified index (0 through 255,
1331 // inclusive) is pushed on the stack
1332 case DW_OP_pick: {
1333 uint8_t pick_idx = opcodes.GetU8(&offset);
1334 if (pick_idx < stack.size())
1335 stack.push_back(stack[stack.size() - 1 - pick_idx]);
1336 else {
1337 if (error_ptr)
1338 error_ptr->SetErrorStringWithFormat(
1339 "Index %u out of range for DW_OP_pick.\n", pick_idx);
1340 return false;
1341 }
1342 } break;
1343
1344 // OPCODE: DW_OP_swap
1345 // OPERANDS: none
1346 // DESCRIPTION: swaps the top two stack entries. The entry at the top
1347 // of the stack becomes the second stack entry, and the second entry
1348 // becomes the top of the stack
1349 case DW_OP_swap:
1350 if (stack.size() < 2) {
1351 if (error_ptr)
1352 error_ptr->SetErrorString(
1353 "Expression stack needs at least 2 items for DW_OP_swap.");
1354 return false;
1355 } else {
1356 tmp = stack.back();
1357 stack.back() = stack[stack.size() - 2];
1358 stack[stack.size() - 2] = tmp;
1359 }
1360 break;
1361
1362 // OPCODE: DW_OP_rot
1363 // OPERANDS: none
1364 // DESCRIPTION: Rotates the first three stack entries. The entry at
1365 // the top of the stack becomes the third stack entry, the second entry
1366 // becomes the top of the stack, and the third entry becomes the second
1367 // entry.
1368 case DW_OP_rot:
1369 if (stack.size() < 3) {
1370 if (error_ptr)
1371 error_ptr->SetErrorString(
1372 "Expression stack needs at least 3 items for DW_OP_rot.");
1373 return false;
1374 } else {
1375 size_t last_idx = stack.size() - 1;
1376 Value old_top = stack[last_idx];
1377 stack[last_idx] = stack[last_idx - 1];
1378 stack[last_idx - 1] = stack[last_idx - 2];
1379 stack[last_idx - 2] = old_top;
1380 }
1381 break;
1382
1383 // OPCODE: DW_OP_abs
1384 // OPERANDS: none
1385 // DESCRIPTION: pops the top stack entry, interprets it as a signed
1386 // value and pushes its absolute value. If the absolute value can not be
1387 // represented, the result is undefined.
1388 case DW_OP_abs:
1389 if (stack.empty()) {
1390 if (error_ptr)
1391 error_ptr->SetErrorString(
1392 "Expression stack needs at least 1 item for DW_OP_abs.");
1393 return false;
1394 } else if (!stack.back().ResolveValue(exe_ctx).AbsoluteValue()) {
1395 if (error_ptr)
1396 error_ptr->SetErrorString(
1397 "Failed to take the absolute value of the first stack item.");
1398 return false;
1399 }
1400 break;
1401
1402 // OPCODE: DW_OP_and
1403 // OPERANDS: none
1404 // DESCRIPTION: pops the top two stack values, performs a bitwise and
1405 // operation on the two, and pushes the result.
1406 case DW_OP_and:
1407 if (stack.size() < 2) {
1408 if (error_ptr)
1409 error_ptr->SetErrorString(
1410 "Expression stack needs at least 2 items for DW_OP_and.");
1411 return false;
1412 } else {
1413 tmp = stack.back();
1414 stack.pop_back();
1415 stack.back().ResolveValue(exe_ctx) =
1416 stack.back().ResolveValue(exe_ctx) & tmp.ResolveValue(exe_ctx);
1417 }
1418 break;
1419
1420 // OPCODE: DW_OP_div
1421 // OPERANDS: none
1422 // DESCRIPTION: pops the top two stack values, divides the former second
1423 // entry by the former top of the stack using signed division, and pushes
1424 // the result.
1425 case DW_OP_div:
1426 if (stack.size() < 2) {
1427 if (error_ptr)
1428 error_ptr->SetErrorString(
1429 "Expression stack needs at least 2 items for DW_OP_div.");
1430 return false;
1431 } else {
1432 tmp = stack.back();
1433 if (tmp.ResolveValue(exe_ctx).IsZero()) {
1434 if (error_ptr)
1435 error_ptr->SetErrorString("Divide by zero.");
1436 return false;
1437 } else {
1438 stack.pop_back();
1439 stack.back() =
1440 stack.back().ResolveValue(exe_ctx) / tmp.ResolveValue(exe_ctx);
1441 if (!stack.back().ResolveValue(exe_ctx).IsValid()) {
1442 if (error_ptr)
1443 error_ptr->SetErrorString("Divide failed.");
1444 return false;
1445 }
1446 }
1447 }
1448 break;
1449
1450 // OPCODE: DW_OP_minus
1451 // OPERANDS: none
1452 // DESCRIPTION: pops the top two stack values, subtracts the former top
1453 // of the stack from the former second entry, and pushes the result.
1454 case DW_OP_minus:
1455 if (stack.size() < 2) {
1456 if (error_ptr)
1457 error_ptr->SetErrorString(
1458 "Expression stack needs at least 2 items for DW_OP_minus.");
1459 return false;
1460 } else {
1461 tmp = stack.back();
1462 stack.pop_back();
1463 stack.back().ResolveValue(exe_ctx) =
1464 stack.back().ResolveValue(exe_ctx) - tmp.ResolveValue(exe_ctx);
1465 }
1466 break;
1467
1468 // OPCODE: DW_OP_mod
1469 // OPERANDS: none
1470 // DESCRIPTION: pops the top two stack values and pushes the result of
1471 // the calculation: former second stack entry modulo the former top of the
1472 // stack.
1473 case DW_OP_mod:
1474 if (stack.size() < 2) {
1475 if (error_ptr)
1476 error_ptr->SetErrorString(
1477 "Expression stack needs at least 2 items for DW_OP_mod.");
1478 return false;
1479 } else {
1480 tmp = stack.back();
1481 stack.pop_back();
1482 stack.back().ResolveValue(exe_ctx) =
1483 stack.back().ResolveValue(exe_ctx) % tmp.ResolveValue(exe_ctx);
1484 }
1485 break;
1486
1487 // OPCODE: DW_OP_mul
1488 // OPERANDS: none
1489 // DESCRIPTION: pops the top two stack entries, multiplies them
1490 // together, and pushes the result.
1491 case DW_OP_mul:
1492 if (stack.size() < 2) {
1493 if (error_ptr)
1494 error_ptr->SetErrorString(
1495 "Expression stack needs at least 2 items for DW_OP_mul.");
1496 return false;
1497 } else {
1498 tmp = stack.back();
1499 stack.pop_back();
1500 stack.back().ResolveValue(exe_ctx) =
1501 stack.back().ResolveValue(exe_ctx) * tmp.ResolveValue(exe_ctx);
1502 }
1503 break;
1504
1505 // OPCODE: DW_OP_neg
1506 // OPERANDS: none
1507 // DESCRIPTION: pops the top stack entry, and pushes its negation.
1508 case DW_OP_neg:
1509 if (stack.empty()) {
1510 if (error_ptr)
1511 error_ptr->SetErrorString(
1512 "Expression stack needs at least 1 item for DW_OP_neg.");
1513 return false;
1514 } else {
1515 if (!stack.back().ResolveValue(exe_ctx).UnaryNegate()) {
1516 if (error_ptr)
1517 error_ptr->SetErrorString("Unary negate failed.");
1518 return false;
1519 }
1520 }
1521 break;
1522
1523 // OPCODE: DW_OP_not
1524 // OPERANDS: none
1525 // DESCRIPTION: pops the top stack entry, and pushes its bitwise
1526 // complement
1527 case DW_OP_not:
1528 if (stack.empty()) {
1529 if (error_ptr)
1530 error_ptr->SetErrorString(
1531 "Expression stack needs at least 1 item for DW_OP_not.");
1532 return false;
1533 } else {
1534 if (!stack.back().ResolveValue(exe_ctx).OnesComplement()) {
1535 if (error_ptr)
1536 error_ptr->SetErrorString("Logical NOT failed.");
1537 return false;
1538 }
1539 }
1540 break;
1541
1542 // OPCODE: DW_OP_or
1543 // OPERANDS: none
1544 // DESCRIPTION: pops the top two stack entries, performs a bitwise or
1545 // operation on the two, and pushes the result.
1546 case DW_OP_or:
1547 if (stack.size() < 2) {
1548 if (error_ptr)
1549 error_ptr->SetErrorString(
1550 "Expression stack needs at least 2 items for DW_OP_or.");
1551 return false;
1552 } else {
1553 tmp = stack.back();
1554 stack.pop_back();
1555 stack.back().ResolveValue(exe_ctx) =
1556 stack.back().ResolveValue(exe_ctx) | tmp.ResolveValue(exe_ctx);
1557 }
1558 break;
1559
1560 // OPCODE: DW_OP_plus
1561 // OPERANDS: none
1562 // DESCRIPTION: pops the top two stack entries, adds them together, and
1563 // pushes the result.
1564 case DW_OP_plus:
1565 if (stack.size() < 2) {
1566 if (error_ptr)
1567 error_ptr->SetErrorString(
1568 "Expression stack needs at least 2 items for DW_OP_plus.");
1569 return false;
1570 } else {
1571 tmp = stack.back();
1572 stack.pop_back();
1573 stack.back().GetScalar() += tmp.GetScalar();
1574 }
1575 break;
1576
1577 // OPCODE: DW_OP_plus_uconst
1578 // OPERANDS: none
1579 // DESCRIPTION: pops the top stack entry, adds it to the unsigned LEB128
1580 // constant operand and pushes the result.
1581 case DW_OP_plus_uconst:
1582 if (stack.empty()) {
1583 if (error_ptr)
1584 error_ptr->SetErrorString(
1585 "Expression stack needs at least 1 item for DW_OP_plus_uconst.");
1586 return false;
1587 } else {
1588 const uint64_t uconst_value = opcodes.GetULEB128(&offset);
1589 // Implicit conversion from a UINT to a Scalar...
1590 stack.back().GetScalar() += uconst_value;
1591 if (!stack.back().GetScalar().IsValid()) {
1592 if (error_ptr)
1593 error_ptr->SetErrorString("DW_OP_plus_uconst failed.");
1594 return false;
1595 }
1596 }
1597 break;
1598
1599 // OPCODE: DW_OP_shl
1600 // OPERANDS: none
1601 // DESCRIPTION: pops the top two stack entries, shifts the former
1602 // second entry left by the number of bits specified by the former top of
1603 // the stack, and pushes the result.
1604 case DW_OP_shl:
1605 if (stack.size() < 2) {
1606 if (error_ptr)
1607 error_ptr->SetErrorString(
1608 "Expression stack needs at least 2 items for DW_OP_shl.");
1609 return false;
1610 } else {
1611 tmp = stack.back();
1612 stack.pop_back();
1613 stack.back().ResolveValue(exe_ctx) <<= tmp.ResolveValue(exe_ctx);
1614 }
1615 break;
1616
1617 // OPCODE: DW_OP_shr
1618 // OPERANDS: none
1619 // DESCRIPTION: pops the top two stack entries, shifts the former second
1620 // entry right logically (filling with zero bits) by the number of bits
1621 // specified by the former top of the stack, and pushes the result.
1622 case DW_OP_shr:
1623 if (stack.size() < 2) {
1624 if (error_ptr)
1625 error_ptr->SetErrorString(
1626 "Expression stack needs at least 2 items for DW_OP_shr.");
1627 return false;
1628 } else {
1629 tmp = stack.back();
1630 stack.pop_back();
1631 if (!stack.back().ResolveValue(exe_ctx).ShiftRightLogical(
1632 tmp.ResolveValue(exe_ctx))) {
1633 if (error_ptr)
1634 error_ptr->SetErrorString("DW_OP_shr failed.");
1635 return false;
1636 }
1637 }
1638 break;
1639
1640 // OPCODE: DW_OP_shra
1641 // OPERANDS: none
1642 // DESCRIPTION: pops the top two stack entries, shifts the former second
1643 // entry right arithmetically (divide the magnitude by 2, keep the same
1644 // sign for the result) by the number of bits specified by the former top
1645 // of the stack, and pushes the result.
1646 case DW_OP_shra:
1647 if (stack.size() < 2) {
1648 if (error_ptr)
1649 error_ptr->SetErrorString(
1650 "Expression stack needs at least 2 items for DW_OP_shra.");
1651 return false;
1652 } else {
1653 tmp = stack.back();
1654 stack.pop_back();
1655 stack.back().ResolveValue(exe_ctx) >>= tmp.ResolveValue(exe_ctx);
1656 }
1657 break;
1658
1659 // OPCODE: DW_OP_xor
1660 // OPERANDS: none
1661 // DESCRIPTION: pops the top two stack entries, performs the bitwise
1662 // exclusive-or operation on the two, and pushes the result.
1663 case DW_OP_xor:
1664 if (stack.size() < 2) {
1665 if (error_ptr)
1666 error_ptr->SetErrorString(
1667 "Expression stack needs at least 2 items for DW_OP_xor.");
1668 return false;
1669 } else {
1670 tmp = stack.back();
1671 stack.pop_back();
1672 stack.back().ResolveValue(exe_ctx) =
1673 stack.back().ResolveValue(exe_ctx) ^ tmp.ResolveValue(exe_ctx);
1674 }
1675 break;
1676
1677 // OPCODE: DW_OP_skip
1678 // OPERANDS: int16_t
1679 // DESCRIPTION: An unconditional branch. Its single operand is a 2-byte
1680 // signed integer constant. The 2-byte constant is the number of bytes of
1681 // the DWARF expression to skip forward or backward from the current
1682 // operation, beginning after the 2-byte constant.
1683 case DW_OP_skip: {
1684 int16_t skip_offset = (int16_t)opcodes.GetU16(&offset);
1685 lldb::offset_t new_offset = offset + skip_offset;
1686 // New offset can point at the end of the data, in this case we should
1687 // terminate the DWARF expression evaluation (will happen in the loop
1688 // condition).
1689 if (new_offset <= opcodes.GetByteSize())
1690 offset = new_offset;
1691 else {
1692 if (error_ptr)
1693 error_ptr->SetErrorStringWithFormatv(
1694 "Invalid opcode offset in DW_OP_skip: {0}+({1}) > {2}", offset,
1695 skip_offset, opcodes.GetByteSize());
1696 return false;
1697 }
1698 } break;
1699
1700 // OPCODE: DW_OP_bra
1701 // OPERANDS: int16_t
1702 // DESCRIPTION: A conditional branch. Its single operand is a 2-byte
1703 // signed integer constant. This operation pops the top of stack. If the
1704 // value popped is not the constant 0, the 2-byte constant operand is the
1705 // number of bytes of the DWARF expression to skip forward or backward from
1706 // the current operation, beginning after the 2-byte constant.
1707 case DW_OP_bra:
1708 if (stack.empty()) {
1709 if (error_ptr)
1710 error_ptr->SetErrorString(
1711 "Expression stack needs at least 1 item for DW_OP_bra.");
1712 return false;
1713 } else {
1714 tmp = stack.back();
1715 stack.pop_back();
1716 int16_t bra_offset = (int16_t)opcodes.GetU16(&offset);
1717 Scalar zero(0);
1718 if (tmp.ResolveValue(exe_ctx) != zero) {
1719 lldb::offset_t new_offset = offset + bra_offset;
1720 // New offset can point at the end of the data, in this case we should
1721 // terminate the DWARF expression evaluation (will happen in the loop
1722 // condition).
1723 if (new_offset <= opcodes.GetByteSize())
1724 offset = new_offset;
1725 else {
1726 if (error_ptr)
1727 error_ptr->SetErrorStringWithFormatv(
1728 "Invalid opcode offset in DW_OP_bra: {0}+({1}) > {2}", offset,
1729 bra_offset, opcodes.GetByteSize());
1730 return false;
1731 }
1732 }
1733 }
1734 break;
1735
1736 // OPCODE: DW_OP_eq
1737 // OPERANDS: none
1738 // DESCRIPTION: pops the top two stack values, compares using the
1739 // equals (==) operator.
1740 // STACK RESULT: push the constant value 1 onto the stack if the result
1741 // of the operation is true or the constant value 0 if the result of the
1742 // operation is false.
1743 case DW_OP_eq:
1744 if (stack.size() < 2) {
1745 if (error_ptr)
1746 error_ptr->SetErrorString(
1747 "Expression stack needs at least 2 items for DW_OP_eq.");
1748 return false;
1749 } else {
1750 tmp = stack.back();
1751 stack.pop_back();
1752 stack.back().ResolveValue(exe_ctx) =
1753 stack.back().ResolveValue(exe_ctx) == tmp.ResolveValue(exe_ctx);
1754 }
1755 break;
1756
1757 // OPCODE: DW_OP_ge
1758 // OPERANDS: none
1759 // DESCRIPTION: pops the top two stack values, compares using the
1760 // greater than or equal to (>=) operator.
1761 // STACK RESULT: push the constant value 1 onto the stack if the result
1762 // of the operation is true or the constant value 0 if the result of the
1763 // operation is false.
1764 case DW_OP_ge:
1765 if (stack.size() < 2) {
1766 if (error_ptr)
1767 error_ptr->SetErrorString(
1768 "Expression stack needs at least 2 items for DW_OP_ge.");
1769 return false;
1770 } else {
1771 tmp = stack.back();
1772 stack.pop_back();
1773 stack.back().ResolveValue(exe_ctx) =
1774 stack.back().ResolveValue(exe_ctx) >= tmp.ResolveValue(exe_ctx);
1775 }
1776 break;
1777
1778 // OPCODE: DW_OP_gt
1779 // OPERANDS: none
1780 // DESCRIPTION: pops the top two stack values, compares using the
1781 // greater than (>) operator.
1782 // STACK RESULT: push the constant value 1 onto the stack if the result
1783 // of the operation is true or the constant value 0 if the result of the
1784 // operation is false.
1785 case DW_OP_gt:
1786 if (stack.size() < 2) {
1787 if (error_ptr)
1788 error_ptr->SetErrorString(
1789 "Expression stack needs at least 2 items for DW_OP_gt.");
1790 return false;
1791 } else {
1792 tmp = stack.back();
1793 stack.pop_back();
1794 stack.back().ResolveValue(exe_ctx) =
1795 stack.back().ResolveValue(exe_ctx) > tmp.ResolveValue(exe_ctx);
1796 }
1797 break;
1798
1799 // OPCODE: DW_OP_le
1800 // OPERANDS: none
1801 // DESCRIPTION: pops the top two stack values, compares using the
1802 // less than or equal to (<=) operator.
1803 // STACK RESULT: push the constant value 1 onto the stack if the result
1804 // of the operation is true or the constant value 0 if the result of the
1805 // operation is false.
1806 case DW_OP_le:
1807 if (stack.size() < 2) {
1808 if (error_ptr)
1809 error_ptr->SetErrorString(
1810 "Expression stack needs at least 2 items for DW_OP_le.");
1811 return false;
1812 } else {
1813 tmp = stack.back();
1814 stack.pop_back();
1815 stack.back().ResolveValue(exe_ctx) =
1816 stack.back().ResolveValue(exe_ctx) <= tmp.ResolveValue(exe_ctx);
1817 }
1818 break;
1819
1820 // OPCODE: DW_OP_lt
1821 // OPERANDS: none
1822 // DESCRIPTION: pops the top two stack values, compares using the
1823 // less than (<) operator.
1824 // STACK RESULT: push the constant value 1 onto the stack if the result
1825 // of the operation is true or the constant value 0 if the result of the
1826 // operation is false.
1827 case DW_OP_lt:
1828 if (stack.size() < 2) {
1829 if (error_ptr)
1830 error_ptr->SetErrorString(
1831 "Expression stack needs at least 2 items for DW_OP_lt.");
1832 return false;
1833 } else {
1834 tmp = stack.back();
1835 stack.pop_back();
1836 stack.back().ResolveValue(exe_ctx) =
1837 stack.back().ResolveValue(exe_ctx) < tmp.ResolveValue(exe_ctx);
1838 }
1839 break;
1840
1841 // OPCODE: DW_OP_ne
1842 // OPERANDS: none
1843 // DESCRIPTION: pops the top two stack values, compares using the
1844 // not equal (!=) operator.
1845 // STACK RESULT: push the constant value 1 onto the stack if the result
1846 // of the operation is true or the constant value 0 if the result of the
1847 // operation is false.
1848 case DW_OP_ne:
1849 if (stack.size() < 2) {
1850 if (error_ptr)
1851 error_ptr->SetErrorString(
1852 "Expression stack needs at least 2 items for DW_OP_ne.");
1853 return false;
1854 } else {
1855 tmp = stack.back();
1856 stack.pop_back();
1857 stack.back().ResolveValue(exe_ctx) =
1858 stack.back().ResolveValue(exe_ctx) != tmp.ResolveValue(exe_ctx);
1859 }
1860 break;
1861
1862 // OPCODE: DW_OP_litn
1863 // OPERANDS: none
1864 // DESCRIPTION: encode the unsigned literal values from 0 through 31.
1865 // STACK RESULT: push the unsigned literal constant value onto the top
1866 // of the stack.
1867 case DW_OP_lit0:
1868 case DW_OP_lit1:
1869 case DW_OP_lit2:
1870 case DW_OP_lit3:
1871 case DW_OP_lit4:
1872 case DW_OP_lit5:
1873 case DW_OP_lit6:
1874 case DW_OP_lit7:
1875 case DW_OP_lit8:
1876 case DW_OP_lit9:
1877 case DW_OP_lit10:
1878 case DW_OP_lit11:
1879 case DW_OP_lit12:
1880 case DW_OP_lit13:
1881 case DW_OP_lit14:
1882 case DW_OP_lit15:
1883 case DW_OP_lit16:
1884 case DW_OP_lit17:
1885 case DW_OP_lit18:
1886 case DW_OP_lit19:
1887 case DW_OP_lit20:
1888 case DW_OP_lit21:
1889 case DW_OP_lit22:
1890 case DW_OP_lit23:
1891 case DW_OP_lit24:
1892 case DW_OP_lit25:
1893 case DW_OP_lit26:
1894 case DW_OP_lit27:
1895 case DW_OP_lit28:
1896 case DW_OP_lit29:
1897 case DW_OP_lit30:
1898 case DW_OP_lit31:
1899 stack.push_back(to_generic(op - DW_OP_lit0));
1900 break;
1901
1902 // OPCODE: DW_OP_regN
1903 // OPERANDS: none
1904 // DESCRIPTION: Push the value in register n on the top of the stack.
1905 case DW_OP_reg0:
1906 case DW_OP_reg1:
1907 case DW_OP_reg2:
1908 case DW_OP_reg3:
1909 case DW_OP_reg4:
1910 case DW_OP_reg5:
1911 case DW_OP_reg6:
1912 case DW_OP_reg7:
1913 case DW_OP_reg8:
1914 case DW_OP_reg9:
1915 case DW_OP_reg10:
1916 case DW_OP_reg11:
1917 case DW_OP_reg12:
1918 case DW_OP_reg13:
1919 case DW_OP_reg14:
1920 case DW_OP_reg15:
1921 case DW_OP_reg16:
1922 case DW_OP_reg17:
1923 case DW_OP_reg18:
1924 case DW_OP_reg19:
1925 case DW_OP_reg20:
1926 case DW_OP_reg21:
1927 case DW_OP_reg22:
1928 case DW_OP_reg23:
1929 case DW_OP_reg24:
1930 case DW_OP_reg25:
1931 case DW_OP_reg26:
1932 case DW_OP_reg27:
1933 case DW_OP_reg28:
1934 case DW_OP_reg29:
1935 case DW_OP_reg30:
1936 case DW_OP_reg31: {
1937 dwarf4_location_description_kind = Register;
1938 reg_num = op - DW_OP_reg0;
1939
1940 if (ReadRegisterValueAsScalar(reg_ctx, reg_kind, reg_num, error_ptr, tmp))
1941 stack.push_back(tmp);
1942 else
1943 return false;
1944 } break;
1945 // OPCODE: DW_OP_regx
1946 // OPERANDS:
1947 // ULEB128 literal operand that encodes the register.
1948 // DESCRIPTION: Push the value in register on the top of the stack.
1949 case DW_OP_regx: {
1950 dwarf4_location_description_kind = Register;
1951 reg_num = opcodes.GetULEB128(&offset);
1952 if (ReadRegisterValueAsScalar(reg_ctx, reg_kind, reg_num, error_ptr, tmp))
1953 stack.push_back(tmp);
1954 else
1955 return false;
1956 } break;
1957
1958 // OPCODE: DW_OP_bregN
1959 // OPERANDS:
1960 // SLEB128 offset from register N
1961 // DESCRIPTION: Value is in memory at the address specified by register
1962 // N plus an offset.
1963 case DW_OP_breg0:
1964 case DW_OP_breg1:
1965 case DW_OP_breg2:
1966 case DW_OP_breg3:
1967 case DW_OP_breg4:
1968 case DW_OP_breg5:
1969 case DW_OP_breg6:
1970 case DW_OP_breg7:
1971 case DW_OP_breg8:
1972 case DW_OP_breg9:
1973 case DW_OP_breg10:
1974 case DW_OP_breg11:
1975 case DW_OP_breg12:
1976 case DW_OP_breg13:
1977 case DW_OP_breg14:
1978 case DW_OP_breg15:
1979 case DW_OP_breg16:
1980 case DW_OP_breg17:
1981 case DW_OP_breg18:
1982 case DW_OP_breg19:
1983 case DW_OP_breg20:
1984 case DW_OP_breg21:
1985 case DW_OP_breg22:
1986 case DW_OP_breg23:
1987 case DW_OP_breg24:
1988 case DW_OP_breg25:
1989 case DW_OP_breg26:
1990 case DW_OP_breg27:
1991 case DW_OP_breg28:
1992 case DW_OP_breg29:
1993 case DW_OP_breg30:
1994 case DW_OP_breg31: {
1995 reg_num = op - DW_OP_breg0;
1996
1997 if (ReadRegisterValueAsScalar(reg_ctx, reg_kind, reg_num, error_ptr,
1998 tmp)) {
1999 int64_t breg_offset = opcodes.GetSLEB128(&offset);
2000 tmp.ResolveValue(exe_ctx) += (uint64_t)breg_offset;
2001 tmp.ClearContext();
2002 stack.push_back(tmp);
2003 stack.back().SetValueType(Value::ValueType::LoadAddress);
2004 } else
2005 return false;
2006 } break;
2007 // OPCODE: DW_OP_bregx
2008 // OPERANDS: 2
2009 // ULEB128 literal operand that encodes the register.
2010 // SLEB128 offset from register N
2011 // DESCRIPTION: Value is in memory at the address specified by register
2012 // N plus an offset.
2013 case DW_OP_bregx: {
2014 reg_num = opcodes.GetULEB128(&offset);
2015
2016 if (ReadRegisterValueAsScalar(reg_ctx, reg_kind, reg_num, error_ptr,
2017 tmp)) {
2018 int64_t breg_offset = opcodes.GetSLEB128(&offset);
2019 tmp.ResolveValue(exe_ctx) += (uint64_t)breg_offset;
2020 tmp.ClearContext();
2021 stack.push_back(tmp);
2022 stack.back().SetValueType(Value::ValueType::LoadAddress);
2023 } else
2024 return false;
2025 } break;
2026
2027 case DW_OP_fbreg:
2028 if (exe_ctx) {
2029 if (frame) {
2030 Scalar value;
2031 if (frame->GetFrameBaseValue(value, error_ptr)) {
2032 int64_t fbreg_offset = opcodes.GetSLEB128(&offset);
2033 value += fbreg_offset;
2034 stack.push_back(value);
2035 stack.back().SetValueType(Value::ValueType::LoadAddress);
2036 } else
2037 return false;
2038 } else {
2039 if (error_ptr)
2040 error_ptr->SetErrorString(
2041 "Invalid stack frame in context for DW_OP_fbreg opcode.");
2042 return false;
2043 }
2044 } else {
2045 if (error_ptr)
2046 error_ptr->SetErrorString(
2047 "NULL execution context for DW_OP_fbreg.\n");
2048 return false;
2049 }
2050
2051 break;
2052
2053 // OPCODE: DW_OP_nop
2054 // OPERANDS: none
2055 // DESCRIPTION: A place holder. It has no effect on the location stack
2056 // or any of its values.
2057 case DW_OP_nop:
2058 break;
2059
2060 // OPCODE: DW_OP_piece
2061 // OPERANDS: 1
2062 // ULEB128: byte size of the piece
2063 // DESCRIPTION: The operand describes the size in bytes of the piece of
2064 // the object referenced by the DWARF expression whose result is at the top
2065 // of the stack. If the piece is located in a register, but does not occupy
2066 // the entire register, the placement of the piece within that register is
2067 // defined by the ABI.
2068 //
2069 // Many compilers store a single variable in sets of registers, or store a
2070 // variable partially in memory and partially in registers. DW_OP_piece
2071 // provides a way of describing how large a part of a variable a particular
2072 // DWARF expression refers to.
2073 case DW_OP_piece: {
2074 LocationDescriptionKind piece_locdesc = dwarf4_location_description_kind;
2075 // Reset for the next piece.
2076 dwarf4_location_description_kind = Memory;
2077
2078 const uint64_t piece_byte_size = opcodes.GetULEB128(&offset);
2079
2080 if (piece_byte_size > 0) {
2081 Value curr_piece;
2082
2083 if (stack.empty()) {
2084 UpdateValueTypeFromLocationDescription(
2085 log, dwarf_cu, LocationDescriptionKind::Empty);
2086 // In a multi-piece expression, this means that the current piece is
2087 // not available. Fill with zeros for now by resizing the data and
2088 // appending it
2089 curr_piece.ResizeData(piece_byte_size);
2090 // Note that "0" is not a correct value for the unknown bits.
2091 // It would be better to also return a mask of valid bits together
2092 // with the expression result, so the debugger can print missing
2093 // members as "<optimized out>" or something.
2094 ::memset(curr_piece.GetBuffer().GetBytes(), 0, piece_byte_size);
2095 pieces.AppendDataToHostBuffer(curr_piece);
2096 } else {
2097 Status error;
2098 // Extract the current piece into "curr_piece"
2099 Value curr_piece_source_value(stack.back());
2100 stack.pop_back();
2101 UpdateValueTypeFromLocationDescription(log, dwarf_cu, piece_locdesc,
2102 &curr_piece_source_value);
2103
2104 const Value::ValueType curr_piece_source_value_type =
2105 curr_piece_source_value.GetValueType();
2106 switch (curr_piece_source_value_type) {
2107 case Value::ValueType::Invalid:
2108 return false;
2109 case Value::ValueType::LoadAddress:
2110 if (process) {
2111 if (curr_piece.ResizeData(piece_byte_size) == piece_byte_size) {
2112 lldb::addr_t load_addr =
2113 curr_piece_source_value.GetScalar().ULongLong(
2114 LLDB_INVALID_ADDRESS(18446744073709551615UL));
2115 if (process->ReadMemory(
2116 load_addr, curr_piece.GetBuffer().GetBytes(),
2117 piece_byte_size, error) != piece_byte_size) {
2118 if (error_ptr)
2119 error_ptr->SetErrorStringWithFormat(
2120 "failed to read memory DW_OP_piece(%" PRIu64"l" "u"
2121 ") from 0x%" PRIx64"l" "x",
2122 piece_byte_size, load_addr);
2123 return false;
2124 }
2125 } else {
2126 if (error_ptr)
2127 error_ptr->SetErrorStringWithFormat(
2128 "failed to resize the piece memory buffer for "
2129 "DW_OP_piece(%" PRIu64"l" "u" ")",
2130 piece_byte_size);
2131 return false;
2132 }
2133 }
2134 break;
2135
2136 case Value::ValueType::FileAddress:
2137 case Value::ValueType::HostAddress:
2138 if (error_ptr) {
2139 lldb::addr_t addr = curr_piece_source_value.GetScalar().ULongLong(
2140 LLDB_INVALID_ADDRESS(18446744073709551615UL));
2141 error_ptr->SetErrorStringWithFormat(
2142 "failed to read memory DW_OP_piece(%" PRIu64"l" "u"
2143 ") from %s address 0x%" PRIx64"l" "x",
2144 piece_byte_size, curr_piece_source_value.GetValueType() ==
2145 Value::ValueType::FileAddress
2146 ? "file"
2147 : "host",
2148 addr);
2149 }
2150 return false;
2151
2152 case Value::ValueType::Scalar: {
2153 uint32_t bit_size = piece_byte_size * 8;
2154 uint32_t bit_offset = 0;
2155 Scalar &scalar = curr_piece_source_value.GetScalar();
2156 if (!scalar.ExtractBitfield(
2157 bit_size, bit_offset)) {
2158 if (error_ptr)
2159 error_ptr->SetErrorStringWithFormat(
2160 "unable to extract %" PRIu64"l" "u" " bytes from a %" PRIu64"l" "u"
2161 " byte scalar value.",
2162 piece_byte_size,
2163 (uint64_t)curr_piece_source_value.GetScalar()
2164 .GetByteSize());
2165 return false;
2166 }
2167 // Create curr_piece with bit_size. By default Scalar
2168 // grows to the nearest host integer type.
2169 llvm::APInt fail_value(1, 0, false);
2170 llvm::APInt ap_int = scalar.UInt128(fail_value);
2171 assert(ap_int.getBitWidth() >= bit_size)(static_cast <bool> (ap_int.getBitWidth() >= bit_size
) ? void (0) : __assert_fail ("ap_int.getBitWidth() >= bit_size"
, "lldb/source/Expression/DWARFExpression.cpp", 2171, __extension__
__PRETTY_FUNCTION__))
;
2172 llvm::ArrayRef<uint64_t> buf{ap_int.getRawData(),
2173 ap_int.getNumWords()};
2174 curr_piece.GetScalar() = Scalar(llvm::APInt(bit_size, buf));
2175 } break;
2176 }
2177
2178 // Check if this is the first piece?
2179 if (op_piece_offset == 0) {
2180 // This is the first piece, we should push it back onto the stack
2181 // so subsequent pieces will be able to access this piece and add
2182 // to it.
2183 if (pieces.AppendDataToHostBuffer(curr_piece) == 0) {
2184 if (error_ptr)
2185 error_ptr->SetErrorString("failed to append piece data");
2186 return false;
2187 }
2188 } else {
2189 // If this is the second or later piece there should be a value on
2190 // the stack.
2191 if (pieces.GetBuffer().GetByteSize() != op_piece_offset) {
2192 if (error_ptr)
2193 error_ptr->SetErrorStringWithFormat(
2194 "DW_OP_piece for offset %" PRIu64"l" "u"
2195 " but top of stack is of size %" PRIu64"l" "u",
2196 op_piece_offset, pieces.GetBuffer().GetByteSize());
2197 return false;
2198 }
2199
2200 if (pieces.AppendDataToHostBuffer(curr_piece) == 0) {
2201 if (error_ptr)
2202 error_ptr->SetErrorString("failed to append piece data");
2203 return false;
2204 }
2205 }
2206 }
2207 op_piece_offset += piece_byte_size;
2208 }
2209 } break;
2210
2211 case DW_OP_bit_piece: // 0x9d ULEB128 bit size, ULEB128 bit offset (DWARF3);
2212 if (stack.size() < 1) {
2213 UpdateValueTypeFromLocationDescription(log, dwarf_cu,
2214 LocationDescriptionKind::Empty);
2215 // Reset for the next piece.
2216 dwarf4_location_description_kind = Memory;
Value stored to 'dwarf4_location_description_kind' is never read
2217 if (error_ptr)
2218 error_ptr->SetErrorString(
2219 "Expression stack needs at least 1 item for DW_OP_bit_piece.");
2220 return false;
2221 } else {
2222 UpdateValueTypeFromLocationDescription(
2223 log, dwarf_cu, dwarf4_location_description_kind, &stack.back());
2224 // Reset for the next piece.
2225 dwarf4_location_description_kind = Memory;
2226 const uint64_t piece_bit_size = opcodes.GetULEB128(&offset);
2227 const uint64_t piece_bit_offset = opcodes.GetULEB128(&offset);
2228 switch (stack.back().GetValueType()) {
2229 case Value::ValueType::Invalid:
2230 return false;
2231 case Value::ValueType::Scalar: {
2232 if (!stack.back().GetScalar().ExtractBitfield(piece_bit_size,
2233 piece_bit_offset)) {
2234 if (error_ptr)
2235 error_ptr->SetErrorStringWithFormat(
2236 "unable to extract %" PRIu64"l" "u" " bit value with %" PRIu64"l" "u"
2237 " bit offset from a %" PRIu64"l" "u" " bit scalar value.",
2238 piece_bit_size, piece_bit_offset,
2239 (uint64_t)(stack.back().GetScalar().GetByteSize() * 8));
2240 return false;
2241 }
2242 } break;
2243
2244 case Value::ValueType::FileAddress:
2245 case Value::ValueType::LoadAddress:
2246 case Value::ValueType::HostAddress:
2247 if (error_ptr) {
2248 error_ptr->SetErrorStringWithFormat(
2249 "unable to extract DW_OP_bit_piece(bit_size = %" PRIu64"l" "u"
2250 ", bit_offset = %" PRIu64"l" "u" ") from an address value.",
2251 piece_bit_size, piece_bit_offset);
2252 }
2253 return false;
2254 }
2255 }
2256 break;
2257
2258 // OPCODE: DW_OP_implicit_value
2259 // OPERANDS: 2
2260 // ULEB128 size of the value block in bytes
2261 // uint8_t* block bytes encoding value in target's memory
2262 // representation
2263 // DESCRIPTION: Value is immediately stored in block in the debug info with
2264 // the memory representation of the target.
2265 case DW_OP_implicit_value: {
2266 dwarf4_location_description_kind = Implicit;
2267
2268 const uint32_t len = opcodes.GetULEB128(&offset);
2269 const void *data = opcodes.GetData(&offset, len);
2270
2271 if (!data) {
2272 LLDB_LOG(log, "Evaluate_DW_OP_implicit_value: could not be read data")do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Format("lldb/source/Expression/DWARFExpression.cpp"
, __func__, "Evaluate_DW_OP_implicit_value: could not be read data"
); } while (0)
;
2273 LLDB_ERRORF(error_ptr, "Could not evaluate %s.",do { if (error_ptr) { (error_ptr)->SetErrorStringWithFormat
(("Could not evaluate %s."), DW_OP_value_to_name(op)); } } while
(0);
2274 DW_OP_value_to_name(op))do { if (error_ptr) { (error_ptr)->SetErrorStringWithFormat
(("Could not evaluate %s."), DW_OP_value_to_name(op)); } } while
(0);
;
2275 return false;
2276 }
2277
2278 Value result(data, len);
2279 stack.push_back(result);
2280 break;
2281 }
2282
2283 case DW_OP_implicit_pointer: {
2284 dwarf4_location_description_kind = Implicit;
2285 LLDB_ERRORF(error_ptr, "Could not evaluate %s.", DW_OP_value_to_name(op))do { if (error_ptr) { (error_ptr)->SetErrorStringWithFormat
(("Could not evaluate %s."), DW_OP_value_to_name(op)); } } while
(0);
;
2286 return false;
2287 }
2288
2289 // OPCODE: DW_OP_push_object_address
2290 // OPERANDS: none
2291 // DESCRIPTION: Pushes the address of the object currently being
2292 // evaluated as part of evaluation of a user presented expression. This
2293 // object may correspond to an independent variable described by its own
2294 // DIE or it may be a component of an array, structure, or class whose
2295 // address has been dynamically determined by an earlier step during user
2296 // expression evaluation.
2297 case DW_OP_push_object_address:
2298 if (object_address_ptr)
2299 stack.push_back(*object_address_ptr);
2300 else {
2301 if (error_ptr)
2302 error_ptr->SetErrorString("DW_OP_push_object_address used without "
2303 "specifying an object address");
2304 return false;
2305 }
2306 break;
2307
2308 // OPCODE: DW_OP_call2
2309 // OPERANDS:
2310 // uint16_t compile unit relative offset of a DIE
2311 // DESCRIPTION: Performs subroutine calls during evaluation
2312 // of a DWARF expression. The operand is the 2-byte unsigned offset of a
2313 // debugging information entry in the current compilation unit.
2314 //
2315 // Operand interpretation is exactly like that for DW_FORM_ref2.
2316 //
2317 // This operation transfers control of DWARF expression evaluation to the
2318 // DW_AT_location attribute of the referenced DIE. If there is no such
2319 // attribute, then there is no effect. Execution of the DWARF expression of
2320 // a DW_AT_location attribute may add to and/or remove from values on the
2321 // stack. Execution returns to the point following the call when the end of
2322 // the attribute is reached. Values on the stack at the time of the call
2323 // may be used as parameters by the called expression and values left on
2324 // the stack by the called expression may be used as return values by prior
2325 // agreement between the calling and called expressions.
2326 case DW_OP_call2:
2327 if (error_ptr)
2328 error_ptr->SetErrorString("Unimplemented opcode DW_OP_call2.");
2329 return false;
2330 // OPCODE: DW_OP_call4
2331 // OPERANDS: 1
2332 // uint32_t compile unit relative offset of a DIE
2333 // DESCRIPTION: Performs a subroutine call during evaluation of a DWARF
2334 // expression. For DW_OP_call4, the operand is a 4-byte unsigned offset of
2335 // a debugging information entry in the current compilation unit.
2336 //
2337 // Operand interpretation DW_OP_call4 is exactly like that for
2338 // DW_FORM_ref4.
2339 //
2340 // This operation transfers control of DWARF expression evaluation to the
2341 // DW_AT_location attribute of the referenced DIE. If there is no such
2342 // attribute, then there is no effect. Execution of the DWARF expression of
2343 // a DW_AT_location attribute may add to and/or remove from values on the
2344 // stack. Execution returns to the point following the call when the end of
2345 // the attribute is reached. Values on the stack at the time of the call
2346 // may be used as parameters by the called expression and values left on
2347 // the stack by the called expression may be used as return values by prior
2348 // agreement between the calling and called expressions.
2349 case DW_OP_call4:
2350 if (error_ptr)
2351 error_ptr->SetErrorString("Unimplemented opcode DW_OP_call4.");
2352 return false;
2353
2354 // OPCODE: DW_OP_stack_value
2355 // OPERANDS: None
2356 // DESCRIPTION: Specifies that the object does not exist in memory but
2357 // rather is a constant value. The value from the top of the stack is the
2358 // value to be used. This is the actual object value and not the location.
2359 case DW_OP_stack_value:
2360 dwarf4_location_description_kind = Implicit;
2361 if (stack.empty()) {
2362 if (error_ptr)
2363 error_ptr->SetErrorString(
2364 "Expression stack needs at least 1 item for DW_OP_stack_value.");
2365 return false;
2366 }
2367 stack.back().SetValueType(Value::ValueType::Scalar);
2368 break;
2369
2370 // OPCODE: DW_OP_convert
2371 // OPERANDS: 1
2372 // A ULEB128 that is either a DIE offset of a
2373 // DW_TAG_base_type or 0 for the generic (pointer-sized) type.
2374 //
2375 // DESCRIPTION: Pop the top stack element, convert it to a
2376 // different type, and push the result.
2377 case DW_OP_convert: {
2378 if (stack.size() < 1) {
2379 if (error_ptr)
2380 error_ptr->SetErrorString(
2381 "Expression stack needs at least 1 item for DW_OP_convert.");
2382 return false;
2383 }
2384 const uint64_t die_offset = opcodes.GetULEB128(&offset);
2385 uint64_t bit_size;
2386 bool sign;
2387 if (die_offset == 0) {
2388 // The generic type has the size of an address on the target
2389 // machine and an unspecified signedness. Scalar has no
2390 // "unspecified signedness", so we use unsigned types.
2391 if (!module_sp) {
2392 if (error_ptr)
2393 error_ptr->SetErrorString("No module");
2394 return false;
2395 }
2396 sign = false;
2397 bit_size = module_sp->GetArchitecture().GetAddressByteSize() * 8;
2398 if (!bit_size) {
2399 if (error_ptr)
2400 error_ptr->SetErrorString("unspecified architecture");
2401 return false;
2402 }
2403 } else {
2404 // Retrieve the type DIE that the value is being converted to. This
2405 // offset is compile unit relative so we need to fix it up.
2406 const uint64_t abs_die_offset = die_offset + dwarf_cu->GetOffset();
2407 // FIXME: the constness has annoying ripple effects.
2408 DWARFDIE die = const_cast<DWARFUnit *>(dwarf_cu)->GetDIE(abs_die_offset);
2409 if (!die) {
2410 if (error_ptr)
2411 error_ptr->SetErrorString("Cannot resolve DW_OP_convert type DIE");
2412 return false;
2413 }
2414 uint64_t encoding =
2415 die.GetAttributeValueAsUnsigned(DW_AT_encoding, DW_ATE_hi_user);
2416 bit_size = die.GetAttributeValueAsUnsigned(DW_AT_byte_size, 0) * 8;
2417 if (!bit_size)
2418 bit_size = die.GetAttributeValueAsUnsigned(DW_AT_bit_size, 0);
2419 if (!bit_size) {
2420 if (error_ptr)
2421 error_ptr->SetErrorString("Unsupported type size in DW_OP_convert");
2422 return false;
2423 }
2424 switch (encoding) {
2425 case DW_ATE_signed:
2426 case DW_ATE_signed_char:
2427 sign = true;
2428 break;
2429 case DW_ATE_unsigned:
2430 case DW_ATE_unsigned_char:
2431 sign = false;
2432 break;
2433 default:
2434 if (error_ptr)
2435 error_ptr->SetErrorString("Unsupported encoding in DW_OP_convert");
2436 return false;
2437 }
2438 }
2439 Scalar &top = stack.back().ResolveValue(exe_ctx);
2440 top.TruncOrExtendTo(bit_size, sign);
2441 break;
2442 }
2443
2444 // OPCODE: DW_OP_call_frame_cfa
2445 // OPERANDS: None
2446 // DESCRIPTION: Specifies a DWARF expression that pushes the value of
2447 // the canonical frame address consistent with the call frame information
2448 // located in .debug_frame (or in the FDEs of the eh_frame section).
2449 case DW_OP_call_frame_cfa:
2450 if (frame) {
2451 // Note that we don't have to parse FDEs because this DWARF expression
2452 // is commonly evaluated with a valid stack frame.
2453 StackID id = frame->GetStackID();
2454 addr_t cfa = id.GetCallFrameAddress();
2455 if (cfa != LLDB_INVALID_ADDRESS(18446744073709551615UL)) {
2456 stack.push_back(Scalar(cfa));
2457 stack.back().SetValueType(Value::ValueType::LoadAddress);
2458 } else if (error_ptr)
2459 error_ptr->SetErrorString("Stack frame does not include a canonical "
2460 "frame address for DW_OP_call_frame_cfa "
2461 "opcode.");
2462 } else {
2463 if (error_ptr)
2464 error_ptr->SetErrorString("Invalid stack frame in context for "
2465 "DW_OP_call_frame_cfa opcode.");
2466 return false;
2467 }
2468 break;
2469
2470 // OPCODE: DW_OP_form_tls_address (or the old pre-DWARFv3 vendor extension
2471 // opcode, DW_OP_GNU_push_tls_address)
2472 // OPERANDS: none
2473 // DESCRIPTION: Pops a TLS offset from the stack, converts it to
2474 // an address in the current thread's thread-local storage block, and
2475 // pushes it on the stack.
2476 case DW_OP_form_tls_address:
2477 case DW_OP_GNU_push_tls_address: {
2478 if (stack.size() < 1) {
2479 if (error_ptr) {
2480 if (op == DW_OP_form_tls_address)
2481 error_ptr->SetErrorString(
2482 "DW_OP_form_tls_address needs an argument.");
2483 else
2484 error_ptr->SetErrorString(
2485 "DW_OP_GNU_push_tls_address needs an argument.");
2486 }
2487 return false;
2488 }
2489
2490 if (!exe_ctx || !module_sp) {
2491 if (error_ptr)
2492 error_ptr->SetErrorString("No context to evaluate TLS within.");
2493 return false;
2494 }
2495
2496 Thread *thread = exe_ctx->GetThreadPtr();
2497 if (!thread) {
2498 if (error_ptr)
2499 error_ptr->SetErrorString("No thread to evaluate TLS within.");
2500 return false;
2501 }
2502
2503 // Lookup the TLS block address for this thread and module.
2504 const addr_t tls_file_addr =
2505 stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS(18446744073709551615UL));
2506 const addr_t tls_load_addr =
2507 thread->GetThreadLocalData(module_sp, tls_file_addr);
2508
2509 if (tls_load_addr == LLDB_INVALID_ADDRESS(18446744073709551615UL)) {
2510 if (error_ptr)
2511 error_ptr->SetErrorString(
2512 "No TLS data currently exists for this thread.");
2513 return false;
2514 }
2515
2516 stack.back().GetScalar() = tls_load_addr;
2517 stack.back().SetValueType(Value::ValueType::LoadAddress);
2518 } break;
2519
2520 // OPCODE: DW_OP_addrx (DW_OP_GNU_addr_index is the legacy name.)
2521 // OPERANDS: 1
2522 // ULEB128: index to the .debug_addr section
2523 // DESCRIPTION: Pushes an address to the stack from the .debug_addr
2524 // section with the base address specified by the DW_AT_addr_base attribute
2525 // and the 0 based index is the ULEB128 encoded index.
2526 case DW_OP_addrx:
2527 case DW_OP_GNU_addr_index: {
2528 if (!dwarf_cu) {
2529 if (error_ptr)
2530 error_ptr->SetErrorString("DW_OP_GNU_addr_index found without a "
2531 "compile unit being specified");
2532 return false;
2533 }
2534 uint64_t index = opcodes.GetULEB128(&offset);
2535 lldb::addr_t value = dwarf_cu->ReadAddressFromDebugAddrSection(index);
2536 stack.push_back(Scalar(value));
2537 if (target &&
2538 target->GetArchitecture().GetCore() == ArchSpec::eCore_wasm32) {
2539 // wasm file sections aren't mapped into memory, therefore addresses can
2540 // never point into a file section and are always LoadAddresses.
2541 stack.back().SetValueType(Value::ValueType::LoadAddress);
2542 } else {
2543 stack.back().SetValueType(Value::ValueType::FileAddress);
2544 }
2545 } break;
2546
2547 // OPCODE: DW_OP_GNU_const_index
2548 // OPERANDS: 1
2549 // ULEB128: index to the .debug_addr section
2550 // DESCRIPTION: Pushes an constant with the size of a machine address to
2551 // the stack from the .debug_addr section with the base address specified
2552 // by the DW_AT_addr_base attribute and the 0 based index is the ULEB128
2553 // encoded index.
2554 case DW_OP_GNU_const_index: {
2555 if (!dwarf_cu) {
2556 if (error_ptr)
2557 error_ptr->SetErrorString("DW_OP_GNU_const_index found without a "
2558 "compile unit being specified");
2559 return false;
2560 }
2561 uint64_t index = opcodes.GetULEB128(&offset);
2562 lldb::addr_t value = dwarf_cu->ReadAddressFromDebugAddrSection(index);
2563 stack.push_back(Scalar(value));
2564 } break;
2565
2566 case DW_OP_GNU_entry_value:
2567 case DW_OP_entry_value: {
2568 if (!Evaluate_DW_OP_entry_value(stack, exe_ctx, reg_ctx, opcodes, offset,
2569 error_ptr, log)) {
2570 LLDB_ERRORF(error_ptr, "Could not evaluate %s.",do { if (error_ptr) { (error_ptr)->SetErrorStringWithFormat
(("Could not evaluate %s."), DW_OP_value_to_name(op)); } } while
(0);
2571 DW_OP_value_to_name(op))do { if (error_ptr) { (error_ptr)->SetErrorStringWithFormat
(("Could not evaluate %s."), DW_OP_value_to_name(op)); } } while
(0);
;
2572 return false;
2573 }
2574 break;
2575 }
2576
2577 default:
2578 if (dwarf_cu) {
2579 if (dwarf_cu->GetSymbolFileDWARF().ParseVendorDWARFOpcode(
2580 op, opcodes, offset, stack)) {
2581 break;
2582 }
2583 }
2584 if (error_ptr)
2585 error_ptr->SetErrorStringWithFormatv(
2586 "Unhandled opcode {0} in DWARFExpression", LocationAtom(op));
2587 return false;
2588 }
2589 }
2590
2591 if (stack.empty()) {
2592 // Nothing on the stack, check if we created a piece value from DW_OP_piece
2593 // or DW_OP_bit_piece opcodes
2594 if (pieces.GetBuffer().GetByteSize()) {
2595 result = pieces;
2596 return true;
2597 }
2598 if (error_ptr)
2599 error_ptr->SetErrorString("Stack empty after evaluation.");
2600 return false;
2601 }
2602
2603 UpdateValueTypeFromLocationDescription(
2604 log, dwarf_cu, dwarf4_location_description_kind, &stack.back());
2605
2606 if (log && log->GetVerbose()) {
2607 size_t count = stack.size();
2608 LLDB_LOGF(log,do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("Stack after operation has %" "l" "u"
" values:", (uint64_t)count); } while (0)
2609 "Stack after operation has %" PRIu64 " values:", (uint64_t)count)do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf("Stack after operation has %" "l" "u"
" values:", (uint64_t)count); } while (0)
;
2610 for (size_t i = 0; i < count; ++i) {
2611 StreamString new_value;
2612 new_value.Printf("[%" PRIu64"l" "u" "]", (uint64_t)i);
2613 stack[i].Dump(&new_value);
2614 LLDB_LOGF(log, " %s", new_value.GetData())do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf(" %s", new_value.GetData()); } while
(0)
;
2615 }
2616 }
2617 result = stack.back();
2618 return true; // Return true on success
2619}
2620
2621bool DWARFExpression::ParseDWARFLocationList(
2622 const DWARFUnit *dwarf_cu, const DataExtractor &data,
2623 DWARFExpressionList *location_list) {
2624 location_list->Clear();
2625 std::unique_ptr<llvm::DWARFLocationTable> loctable_up =
2626 dwarf_cu->GetLocationTable(data);
2627 Log *log = GetLog(LLDBLog::Expressions);
2628 auto lookup_addr =
2629 [&](uint32_t index) -> std::optional<llvm::object::SectionedAddress> {
2630 addr_t address = dwarf_cu->ReadAddressFromDebugAddrSection(index);
2631 if (address == LLDB_INVALID_ADDRESS(18446744073709551615UL))
2632 return std::nullopt;
2633 return llvm::object::SectionedAddress{address};
2634 };
2635 auto process_list = [&](llvm::Expected<llvm::DWARFLocationExpression> loc) {
2636 if (!loc) {
2637 LLDB_LOG_ERROR(log, loc.takeError(), "{0}")do { ::lldb_private::Log *log_private = (log); ::llvm::Error error_private
= (loc.takeError()); if (log_private && error_private
) { log_private->FormatError(::std::move(error_private), "lldb/source/Expression/DWARFExpression.cpp"
, __func__, "{0}"); } else ::llvm::consumeError(::std::move(error_private
)); } while (0)
;
2638 return true;
2639 }
2640 auto buffer_sp =
2641 std::make_shared<DataBufferHeap>(loc->Expr.data(), loc->Expr.size());
2642 DWARFExpression expr = DWARFExpression(DataExtractor(
2643 buffer_sp, data.GetByteOrder(), data.GetAddressByteSize()));
2644 location_list->AddExpression(loc->Range->LowPC, loc->Range->HighPC, expr);
2645 return true;
2646 };
2647 llvm::Error error = loctable_up->visitAbsoluteLocationList(
2648 0, llvm::object::SectionedAddress{dwarf_cu->GetBaseAddress()},
2649 lookup_addr, process_list);
2650 location_list->Sort();
2651 if (error) {
2652 LLDB_LOG_ERROR(log, std::move(error), "{0}")do { ::lldb_private::Log *log_private = (log); ::llvm::Error error_private
= (std::move(error)); if (log_private && error_private
) { log_private->FormatError(::std::move(error_private), "lldb/source/Expression/DWARFExpression.cpp"
, __func__, "{0}"); } else ::llvm::consumeError(::std::move(error_private
)); } while (0)
;
2653 return false;
2654 }
2655 return true;
2656}
2657
2658bool DWARFExpression::MatchesOperand(
2659 StackFrame &frame, const Instruction::Operand &operand) const {
2660 using namespace OperandMatchers;
2661
2662 RegisterContextSP reg_ctx_sp = frame.GetRegisterContext();
2663 if (!reg_ctx_sp) {
2664 return false;
2665 }
2666
2667 DataExtractor opcodes(m_data);
2668
2669 lldb::offset_t op_offset = 0;
2670 uint8_t opcode = opcodes.GetU8(&op_offset);
2671
2672 if (opcode == DW_OP_fbreg) {
2673 int64_t offset = opcodes.GetSLEB128(&op_offset);
2674
2675 DWARFExpressionList *fb_expr = frame.GetFrameBaseExpression(nullptr);
2676 if (!fb_expr) {
2677 return false;
2678 }
2679
2680 auto recurse = [&frame, fb_expr](const Instruction::Operand &child) {
2681 return fb_expr->MatchesOperand(frame, child);
2682 };
2683
2684 if (!offset &&
2685 MatchUnaryOp(MatchOpType(Instruction::Operand::Type::Dereference),
2686 recurse)(operand)) {
2687 return true;
2688 }
2689
2690 return MatchUnaryOp(
2691 MatchOpType(Instruction::Operand::Type::Dereference),
2692 MatchBinaryOp(MatchOpType(Instruction::Operand::Type::Sum),
2693 MatchImmOp(offset), recurse))(operand);
2694 }
2695
2696 bool dereference = false;
2697 const RegisterInfo *reg = nullptr;
2698 int64_t offset = 0;
2699
2700 if (opcode >= DW_OP_reg0 && opcode <= DW_OP_reg31) {
2701 reg = reg_ctx_sp->GetRegisterInfo(m_reg_kind, opcode - DW_OP_reg0);
2702 } else if (opcode >= DW_OP_breg0 && opcode <= DW_OP_breg31) {
2703 offset = opcodes.GetSLEB128(&op_offset);
2704 reg = reg_ctx_sp->GetRegisterInfo(m_reg_kind, opcode - DW_OP_breg0);
2705 } else if (opcode == DW_OP_regx) {
2706 uint32_t reg_num = static_cast<uint32_t>(opcodes.GetULEB128(&op_offset));
2707 reg = reg_ctx_sp->GetRegisterInfo(m_reg_kind, reg_num);
2708 } else if (opcode == DW_OP_bregx) {
2709 uint32_t reg_num = static_cast<uint32_t>(opcodes.GetULEB128(&op_offset));
2710 offset = opcodes.GetSLEB128(&op_offset);
2711 reg = reg_ctx_sp->GetRegisterInfo(m_reg_kind, reg_num);
2712 } else {
2713 return false;
2714 }
2715
2716 if (!reg) {
2717 return false;
2718 }
2719
2720 if (dereference) {
2721 if (!offset &&
2722 MatchUnaryOp(MatchOpType(Instruction::Operand::Type::Dereference),
2723 MatchRegOp(*reg))(operand)) {
2724 return true;
2725 }
2726
2727 return MatchUnaryOp(
2728 MatchOpType(Instruction::Operand::Type::Dereference),
2729 MatchBinaryOp(MatchOpType(Instruction::Operand::Type::Sum),
2730 MatchRegOp(*reg),
2731 MatchImmOp(offset)))(operand);
2732 } else {
2733 return MatchRegOp(*reg)(operand);
2734 }
2735}