Bug Summary

File:build/source/lldb/source/Expression/DWARFExpression.cpp
Warning:line 2266, column 7
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-16/lib/clang/16.0.0 -isystem /usr/include/libxml2 -D HAVE_ROUND -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -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 _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-16/lib/clang/16.0.0/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/= -source-date-epoch 1668078801 -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-2022-11-10-135928-647445-1 -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 <vector>
14
15#include "lldb/Core/Module.h"
16#include "lldb/Core/Value.h"
17#include "lldb/Core/dwarf.h"
18#include "lldb/Utility/DataEncoder.h"
19#include "lldb/Utility/LLDBLog.h"
20#include "lldb/Utility/Log.h"
21#include "lldb/Utility/RegisterValue.h"
22#include "lldb/Utility/Scalar.h"
23#include "lldb/Utility/StreamString.h"
24#include "lldb/Utility/VMRange.h"
25
26#include "lldb/Host/Host.h"
27#include "lldb/Utility/Endian.h"
28
29#include "lldb/Symbol/Function.h"
30
31#include "lldb/Target/ABI.h"
32#include "lldb/Target/ExecutionContext.h"
33#include "lldb/Target/Process.h"
34#include "lldb/Target/RegisterContext.h"
35#include "lldb/Target/StackFrame.h"
36#include "lldb/Target/StackID.h"
37#include "lldb/Target/Target.h"
38#include "lldb/Target/Thread.h"
39#include "llvm/DebugInfo/DWARF/DWARFDebugLoc.h"
40#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
41
42#include "Plugins/SymbolFile/DWARF/DWARFUnit.h"
43
44using namespace lldb;
45using namespace lldb_private;
46using namespace lldb_private::dwarf;
47
48// DWARFExpression constructor
49DWARFExpression::DWARFExpression() : m_data() {}
50
51DWARFExpression::DWARFExpression(const DataExtractor &data) : m_data(data) {}
52
53// Destructor
54DWARFExpression::~DWARFExpression() = default;
55
56bool DWARFExpression::IsValid() const { return m_data.GetByteSize() > 0; }
57
58void DWARFExpression::UpdateValue(uint64_t const_value,
59 lldb::offset_t const_value_byte_size,
60 uint8_t addr_byte_size) {
61 if (!const_value_byte_size)
62 return;
63
64 m_data.SetData(
65 DataBufferSP(new DataBufferHeap(&const_value, const_value_byte_size)));
66 m_data.SetByteOrder(endian::InlHostByteOrder());
67 m_data.SetAddressByteSize(addr_byte_size);
68}
69
70void DWARFExpression::DumpLocation(Stream *s, lldb::DescriptionLevel level,
71 ABI *abi) const {
72 llvm::DWARFExpression(m_data.GetAsLLVM(), m_data.GetAddressByteSize())
73 .print(s->AsRawOstream(), llvm::DIDumpOptions(),
74 abi ? &abi->GetMCRegisterInfo() : nullptr, nullptr);
75}
76
77RegisterKind DWARFExpression::GetRegisterKind() const { return m_reg_kind; }
78
79void DWARFExpression::SetRegisterKind(RegisterKind reg_kind) {
80 m_reg_kind = reg_kind;
81}
82
83
84static bool ReadRegisterValueAsScalar(RegisterContext *reg_ctx,
85 lldb::RegisterKind reg_kind,
86 uint32_t reg_num, Status *error_ptr,
87 Value &value) {
88 if (reg_ctx == nullptr) {
89 if (error_ptr)
90 error_ptr->SetErrorString("No register context in frame.\n");
91 } else {
92 uint32_t native_reg =
93 reg_ctx->ConvertRegisterKindToRegisterNumber(reg_kind, reg_num);
94 if (native_reg == LLDB_INVALID_REGNUM(4294967295U)) {
95 if (error_ptr)
96 error_ptr->SetErrorStringWithFormat("Unable to convert register "
97 "kind=%u reg_num=%u to a native "
98 "register number.\n",
99 reg_kind, reg_num);
100 } else {
101 const RegisterInfo *reg_info =
102 reg_ctx->GetRegisterInfoAtIndex(native_reg);
103 RegisterValue reg_value;
104 if (reg_ctx->ReadRegister(reg_info, reg_value)) {
105 if (reg_value.GetScalarValue(value.GetScalar())) {
106 value.SetValueType(Value::ValueType::Scalar);
107 value.SetContext(Value::ContextType::RegisterInfo,
108 const_cast<RegisterInfo *>(reg_info));
109 if (error_ptr)
110 error_ptr->Clear();
111 return true;
112 } else {
113 // If we get this error, then we need to implement a value buffer in
114 // the dwarf expression evaluation function...
115 if (error_ptr)
116 error_ptr->SetErrorStringWithFormat(
117 "register %s can't be converted to a scalar value",
118 reg_info->name);
119 }
120 } else {
121 if (error_ptr)
122 error_ptr->SetErrorStringWithFormat("register %s is not available",
123 reg_info->name);
124 }
125 }
126 }
127 return false;
128}
129
130/// Return the length in bytes of the set of operands for \p op. No guarantees
131/// are made on the state of \p data after this call.
132static offset_t GetOpcodeDataSize(const DataExtractor &data,
133 const lldb::offset_t data_offset,
134 const uint8_t op) {
135 lldb::offset_t offset = data_offset;
136 switch (op) {
137 case DW_OP_addr:
138 case DW_OP_call_ref: // 0x9a 1 address sized offset of DIE (DWARF3)
139 return data.GetAddressByteSize();
140
141 // Opcodes with no arguments
142 case DW_OP_deref: // 0x06
143 case DW_OP_dup: // 0x12
144 case DW_OP_drop: // 0x13
145 case DW_OP_over: // 0x14
146 case DW_OP_swap: // 0x16
147 case DW_OP_rot: // 0x17
148 case DW_OP_xderef: // 0x18
149 case DW_OP_abs: // 0x19
150 case DW_OP_and: // 0x1a
151 case DW_OP_div: // 0x1b
152 case DW_OP_minus: // 0x1c
153 case DW_OP_mod: // 0x1d
154 case DW_OP_mul: // 0x1e
155 case DW_OP_neg: // 0x1f
156 case DW_OP_not: // 0x20
157 case DW_OP_or: // 0x21
158 case DW_OP_plus: // 0x22
159 case DW_OP_shl: // 0x24
160 case DW_OP_shr: // 0x25
161 case DW_OP_shra: // 0x26
162 case DW_OP_xor: // 0x27
163 case DW_OP_eq: // 0x29
164 case DW_OP_ge: // 0x2a
165 case DW_OP_gt: // 0x2b
166 case DW_OP_le: // 0x2c
167 case DW_OP_lt: // 0x2d
168 case DW_OP_ne: // 0x2e
169 case DW_OP_lit0: // 0x30
170 case DW_OP_lit1: // 0x31
171 case DW_OP_lit2: // 0x32
172 case DW_OP_lit3: // 0x33
173 case DW_OP_lit4: // 0x34
174 case DW_OP_lit5: // 0x35
175 case DW_OP_lit6: // 0x36
176 case DW_OP_lit7: // 0x37
177 case DW_OP_lit8: // 0x38
178 case DW_OP_lit9: // 0x39
179 case DW_OP_lit10: // 0x3A
180 case DW_OP_lit11: // 0x3B
181 case DW_OP_lit12: // 0x3C
182 case DW_OP_lit13: // 0x3D
183 case DW_OP_lit14: // 0x3E
184 case DW_OP_lit15: // 0x3F
185 case DW_OP_lit16: // 0x40
186 case DW_OP_lit17: // 0x41
187 case DW_OP_lit18: // 0x42
188 case DW_OP_lit19: // 0x43
189 case DW_OP_lit20: // 0x44
190 case DW_OP_lit21: // 0x45
191 case DW_OP_lit22: // 0x46
192 case DW_OP_lit23: // 0x47
193 case DW_OP_lit24: // 0x48
194 case DW_OP_lit25: // 0x49
195 case DW_OP_lit26: // 0x4A
196 case DW_OP_lit27: // 0x4B
197 case DW_OP_lit28: // 0x4C
198 case DW_OP_lit29: // 0x4D
199 case DW_OP_lit30: // 0x4E
200 case DW_OP_lit31: // 0x4f
201 case DW_OP_reg0: // 0x50
202 case DW_OP_reg1: // 0x51
203 case DW_OP_reg2: // 0x52
204 case DW_OP_reg3: // 0x53
205 case DW_OP_reg4: // 0x54
206 case DW_OP_reg5: // 0x55
207 case DW_OP_reg6: // 0x56
208 case DW_OP_reg7: // 0x57
209 case DW_OP_reg8: // 0x58
210 case DW_OP_reg9: // 0x59
211 case DW_OP_reg10: // 0x5A
212 case DW_OP_reg11: // 0x5B
213 case DW_OP_reg12: // 0x5C
214 case DW_OP_reg13: // 0x5D
215 case DW_OP_reg14: // 0x5E
216 case DW_OP_reg15: // 0x5F
217 case DW_OP_reg16: // 0x60
218 case DW_OP_reg17: // 0x61
219 case DW_OP_reg18: // 0x62
220 case DW_OP_reg19: // 0x63
221 case DW_OP_reg20: // 0x64
222 case DW_OP_reg21: // 0x65
223 case DW_OP_reg22: // 0x66
224 case DW_OP_reg23: // 0x67
225 case DW_OP_reg24: // 0x68
226 case DW_OP_reg25: // 0x69
227 case DW_OP_reg26: // 0x6A
228 case DW_OP_reg27: // 0x6B
229 case DW_OP_reg28: // 0x6C
230 case DW_OP_reg29: // 0x6D
231 case DW_OP_reg30: // 0x6E
232 case DW_OP_reg31: // 0x6F
233 case DW_OP_nop: // 0x96
234 case DW_OP_push_object_address: // 0x97 DWARF3
235 case DW_OP_form_tls_address: // 0x9b DWARF3
236 case DW_OP_call_frame_cfa: // 0x9c DWARF3
237 case DW_OP_stack_value: // 0x9f DWARF4
238 case DW_OP_GNU_push_tls_address: // 0xe0 GNU extension
239 return 0;
240
241 // Opcodes with a single 1 byte arguments
242 case DW_OP_const1u: // 0x08 1 1-byte constant
243 case DW_OP_const1s: // 0x09 1 1-byte constant
244 case DW_OP_pick: // 0x15 1 1-byte stack index
245 case DW_OP_deref_size: // 0x94 1 1-byte size of data retrieved
246 case DW_OP_xderef_size: // 0x95 1 1-byte size of data retrieved
247 return 1;
248
249 // Opcodes with a single 2 byte arguments
250 case DW_OP_const2u: // 0x0a 1 2-byte constant
251 case DW_OP_const2s: // 0x0b 1 2-byte constant
252 case DW_OP_skip: // 0x2f 1 signed 2-byte constant
253 case DW_OP_bra: // 0x28 1 signed 2-byte constant
254 case DW_OP_call2: // 0x98 1 2-byte offset of DIE (DWARF3)
255 return 2;
256
257 // Opcodes with a single 4 byte arguments
258 case DW_OP_const4u: // 0x0c 1 4-byte constant
259 case DW_OP_const4s: // 0x0d 1 4-byte constant
260 case DW_OP_call4: // 0x99 1 4-byte offset of DIE (DWARF3)
261 return 4;
262
263 // Opcodes with a single 8 byte arguments
264 case DW_OP_const8u: // 0x0e 1 8-byte constant
265 case DW_OP_const8s: // 0x0f 1 8-byte constant
266 return 8;
267
268 // All opcodes that have a single ULEB (signed or unsigned) argument
269 case DW_OP_addrx: // 0xa1 1 ULEB128 index
270 case DW_OP_constu: // 0x10 1 ULEB128 constant
271 case DW_OP_consts: // 0x11 1 SLEB128 constant
272 case DW_OP_plus_uconst: // 0x23 1 ULEB128 addend
273 case DW_OP_breg0: // 0x70 1 ULEB128 register
274 case DW_OP_breg1: // 0x71 1 ULEB128 register
275 case DW_OP_breg2: // 0x72 1 ULEB128 register
276 case DW_OP_breg3: // 0x73 1 ULEB128 register
277 case DW_OP_breg4: // 0x74 1 ULEB128 register
278 case DW_OP_breg5: // 0x75 1 ULEB128 register
279 case DW_OP_breg6: // 0x76 1 ULEB128 register
280 case DW_OP_breg7: // 0x77 1 ULEB128 register
281 case DW_OP_breg8: // 0x78 1 ULEB128 register
282 case DW_OP_breg9: // 0x79 1 ULEB128 register
283 case DW_OP_breg10: // 0x7a 1 ULEB128 register
284 case DW_OP_breg11: // 0x7b 1 ULEB128 register
285 case DW_OP_breg12: // 0x7c 1 ULEB128 register
286 case DW_OP_breg13: // 0x7d 1 ULEB128 register
287 case DW_OP_breg14: // 0x7e 1 ULEB128 register
288 case DW_OP_breg15: // 0x7f 1 ULEB128 register
289 case DW_OP_breg16: // 0x80 1 ULEB128 register
290 case DW_OP_breg17: // 0x81 1 ULEB128 register
291 case DW_OP_breg18: // 0x82 1 ULEB128 register
292 case DW_OP_breg19: // 0x83 1 ULEB128 register
293 case DW_OP_breg20: // 0x84 1 ULEB128 register
294 case DW_OP_breg21: // 0x85 1 ULEB128 register
295 case DW_OP_breg22: // 0x86 1 ULEB128 register
296 case DW_OP_breg23: // 0x87 1 ULEB128 register
297 case DW_OP_breg24: // 0x88 1 ULEB128 register
298 case DW_OP_breg25: // 0x89 1 ULEB128 register
299 case DW_OP_breg26: // 0x8a 1 ULEB128 register
300 case DW_OP_breg27: // 0x8b 1 ULEB128 register
301 case DW_OP_breg28: // 0x8c 1 ULEB128 register
302 case DW_OP_breg29: // 0x8d 1 ULEB128 register
303 case DW_OP_breg30: // 0x8e 1 ULEB128 register
304 case DW_OP_breg31: // 0x8f 1 ULEB128 register
305 case DW_OP_regx: // 0x90 1 ULEB128 register
306 case DW_OP_fbreg: // 0x91 1 SLEB128 offset
307 case DW_OP_piece: // 0x93 1 ULEB128 size of piece addressed
308 case DW_OP_GNU_addr_index: // 0xfb 1 ULEB128 index
309 case DW_OP_GNU_const_index: // 0xfc 1 ULEB128 index
310 data.Skip_LEB128(&offset);
311 return offset - data_offset;
312
313 // All opcodes that have a 2 ULEB (signed or unsigned) arguments
314 case DW_OP_bregx: // 0x92 2 ULEB128 register followed by SLEB128 offset
315 case DW_OP_bit_piece: // 0x9d ULEB128 bit size, ULEB128 bit offset (DWARF3);
316 data.Skip_LEB128(&offset);
317 data.Skip_LEB128(&offset);
318 return offset - data_offset;
319
320 case DW_OP_implicit_value: // 0x9e ULEB128 size followed by block of that size
321 // (DWARF4)
322 {
323 uint64_t block_len = data.Skip_LEB128(&offset);
324 offset += block_len;
325 return offset - data_offset;
326 }
327
328 case DW_OP_GNU_entry_value:
329 case DW_OP_entry_value: // 0xa3 ULEB128 size + variable-length block
330 {
331 uint64_t subexpr_len = data.GetULEB128(&offset);
332 return (offset - data_offset) + subexpr_len;
333 }
334
335 default:
336 break;
337 }
338 return LLDB_INVALID_OFFSET(18446744073709551615UL);
339}
340
341lldb::addr_t DWARFExpression::GetLocation_DW_OP_addr(const DWARFUnit *dwarf_cu,
342 uint32_t op_addr_idx,
343 bool &error) const {
344 error = false;
345 lldb::offset_t offset = 0;
346 uint32_t curr_op_addr_idx = 0;
347 while (m_data.ValidOffset(offset)) {
348 const uint8_t op = m_data.GetU8(&offset);
349
350 if (op == DW_OP_addr) {
351 const lldb::addr_t op_file_addr = m_data.GetAddress(&offset);
352 if (curr_op_addr_idx == op_addr_idx)
353 return op_file_addr;
354 ++curr_op_addr_idx;
355 } else if (op == DW_OP_GNU_addr_index || op == DW_OP_addrx) {
356 uint64_t index = m_data.GetULEB128(&offset);
357 if (curr_op_addr_idx == op_addr_idx) {
358 if (!dwarf_cu) {
359 error = true;
360 break;
361 }
362
363 return dwarf_cu->ReadAddressFromDebugAddrSection(index);
364 }
365 ++curr_op_addr_idx;
366 } else {
367 const offset_t op_arg_size = GetOpcodeDataSize(m_data, offset, op);
368 if (op_arg_size == LLDB_INVALID_OFFSET(18446744073709551615UL)) {
369 error = true;
370 break;
371 }
372 offset += op_arg_size;
373 }
374 }
375 return LLDB_INVALID_ADDRESS(18446744073709551615UL);
376}
377
378bool DWARFExpression::Update_DW_OP_addr(lldb::addr_t file_addr) {
379 lldb::offset_t offset = 0;
380 while (m_data.ValidOffset(offset)) {
381 const uint8_t op = m_data.GetU8(&offset);
382
383 if (op == DW_OP_addr) {
384 const uint32_t addr_byte_size = m_data.GetAddressByteSize();
385 // We have to make a copy of the data as we don't know if this data is
386 // from a read only memory mapped buffer, so we duplicate all of the data
387 // first, then modify it, and if all goes well, we then replace the data
388 // for this expression
389
390 // Make en encoder that contains a copy of the location expression data
391 // so we can write the address into the buffer using the correct byte
392 // order.
393 DataEncoder encoder(m_data.GetDataStart(), m_data.GetByteSize(),
394 m_data.GetByteOrder(), addr_byte_size);
395
396 // Replace the address in the new buffer
397 if (encoder.PutAddress(offset, file_addr) == UINT32_MAX(4294967295U))
398 return false;
399
400 // All went well, so now we can reset the data using a shared pointer to
401 // the heap data so "m_data" will now correctly manage the heap data.
402 m_data.SetData(encoder.GetDataBuffer());
403 return true;
404 } else {
405 const offset_t op_arg_size = GetOpcodeDataSize(m_data, offset, op);
406 if (op_arg_size == LLDB_INVALID_OFFSET(18446744073709551615UL))
407 break;
408 offset += op_arg_size;
409 }
410 }
411 return false;
412}
413
414bool DWARFExpression::ContainsThreadLocalStorage() const {
415 lldb::offset_t offset = 0;
416 while (m_data.ValidOffset(offset)) {
417 const uint8_t op = m_data.GetU8(&offset);
418
419 if (op == DW_OP_form_tls_address || op == DW_OP_GNU_push_tls_address)
420 return true;
421 const offset_t op_arg_size = GetOpcodeDataSize(m_data, offset, op);
422 if (op_arg_size == LLDB_INVALID_OFFSET(18446744073709551615UL))
423 return false;
424 offset += op_arg_size;
425 }
426 return false;
427}
428bool DWARFExpression::LinkThreadLocalStorage(
429 std::function<lldb::addr_t(lldb::addr_t file_addr)> const
430 &link_address_callback) {
431 const uint32_t addr_byte_size = m_data.GetAddressByteSize();
432 // We have to make a copy of the data as we don't know if this data is from a
433 // read only memory mapped buffer, so we duplicate all of the data first,
434 // then modify it, and if all goes well, we then replace the data for this
435 // expression.
436 // Make en encoder that contains a copy of the location expression data so we
437 // can write the address into the buffer using the correct byte order.
438 DataEncoder encoder(m_data.GetDataStart(), m_data.GetByteSize(),
439 m_data.GetByteOrder(), addr_byte_size);
440
441 lldb::offset_t offset = 0;
442 lldb::offset_t const_offset = 0;
443 lldb::addr_t const_value = 0;
444 size_t const_byte_size = 0;
445 while (m_data.ValidOffset(offset)) {
446 const uint8_t op = m_data.GetU8(&offset);
447
448 bool decoded_data = false;
449 switch (op) {
450 case DW_OP_const4u:
451 // Remember the const offset in case we later have a
452 // DW_OP_form_tls_address or DW_OP_GNU_push_tls_address
453 const_offset = offset;
454 const_value = m_data.GetU32(&offset);
455 decoded_data = true;
456 const_byte_size = 4;
457 break;
458
459 case DW_OP_const8u:
460 // Remember the const offset in case we later have a
461 // DW_OP_form_tls_address or DW_OP_GNU_push_tls_address
462 const_offset = offset;
463 const_value = m_data.GetU64(&offset);
464 decoded_data = true;
465 const_byte_size = 8;
466 break;
467
468 case DW_OP_form_tls_address:
469 case DW_OP_GNU_push_tls_address:
470 // DW_OP_form_tls_address and DW_OP_GNU_push_tls_address must be preceded
471 // by a file address on the stack. We assume that DW_OP_const4u or
472 // DW_OP_const8u is used for these values, and we check that the last
473 // opcode we got before either of these was DW_OP_const4u or
474 // DW_OP_const8u. If so, then we can link the value accordingly. For
475 // Darwin, the value in the DW_OP_const4u or DW_OP_const8u is the file
476 // address of a structure that contains a function pointer, the pthread
477 // key and the offset into the data pointed to by the pthread key. So we
478 // must link this address and also set the module of this expression to
479 // the new_module_sp so we can resolve the file address correctly
480 if (const_byte_size > 0) {
481 lldb::addr_t linked_file_addr = link_address_callback(const_value);
482 if (linked_file_addr == LLDB_INVALID_ADDRESS(18446744073709551615UL))
483 return false;
484 // Replace the address in the new buffer
485 if (encoder.PutUnsigned(const_offset, const_byte_size,
486 linked_file_addr) == UINT32_MAX(4294967295U))
487 return false;
488 }
489 break;
490
491 default:
492 const_offset = 0;
493 const_value = 0;
494 const_byte_size = 0;
495 break;
496 }
497
498 if (!decoded_data) {
499 const offset_t op_arg_size = GetOpcodeDataSize(m_data, offset, op);
500 if (op_arg_size == LLDB_INVALID_OFFSET(18446744073709551615UL))
501 return false;
502 else
503 offset += op_arg_size;
504 }
505 }
506
507 m_data.SetData(encoder.GetDataBuffer());
508 return true;
509}
510
511static bool Evaluate_DW_OP_entry_value(std::vector<Value> &stack,
512 ExecutionContext *exe_ctx,
513 RegisterContext *reg_ctx,
514 const DataExtractor &opcodes,
515 lldb::offset_t &opcode_offset,
516 Status *error_ptr, Log *log) {
517 // DW_OP_entry_value(sub-expr) describes the location a variable had upon
518 // function entry: this variable location is presumed to be optimized out at
519 // the current PC value. The caller of the function may have call site
520 // information that describes an alternate location for the variable (e.g. a
521 // constant literal, or a spilled stack value) in the parent frame.
522 //
523 // Example (this is pseudo-code & pseudo-DWARF, but hopefully illustrative):
524 //
525 // void child(int &sink, int x) {
526 // ...
527 // /* "x" gets optimized out. */
528 //
529 // /* The location of "x" here is: DW_OP_entry_value($reg2). */
530 // ++sink;
531 // }
532 //
533 // void parent() {
534 // int sink;
535 //
536 // /*
537 // * The callsite information emitted here is:
538 // *
539 // * DW_TAG_call_site
540 // * DW_AT_return_pc ... (for "child(sink, 123);")
541 // * DW_TAG_call_site_parameter (for "sink")
542 // * DW_AT_location ($reg1)
543 // * DW_AT_call_value ($SP - 8)
544 // * DW_TAG_call_site_parameter (for "x")
545 // * DW_AT_location ($reg2)
546 // * DW_AT_call_value ($literal 123)
547 // *
548 // * DW_TAG_call_site
549 // * DW_AT_return_pc ... (for "child(sink, 456);")
550 // * ...
551 // */
552 // child(sink, 123);
553 // child(sink, 456);
554 // }
555 //
556 // When the program stops at "++sink" within `child`, the debugger determines
557 // the call site by analyzing the return address. Once the call site is found,
558 // the debugger determines which parameter is referenced by DW_OP_entry_value
559 // and evaluates the corresponding location for that parameter in `parent`.
560
561 // 1. Find the function which pushed the current frame onto the stack.
562 if ((!exe_ctx || !exe_ctx->HasTargetScope()) || !reg_ctx) {
563 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)
;
564 return false;
565 }
566
567 StackFrame *current_frame = exe_ctx->GetFramePtr();
568 Thread *thread = exe_ctx->GetThreadPtr();
569 if (!current_frame || !thread) {
570 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)
;
571 return false;
572 }
573
574 Target &target = exe_ctx->GetTargetRef();
575 StackFrameSP parent_frame = nullptr;
576 addr_t return_pc = LLDB_INVALID_ADDRESS(18446744073709551615UL);
577 uint32_t current_frame_idx = current_frame->GetFrameIndex();
578 uint32_t num_frames = thread->GetStackFrameCount();
579 for (uint32_t parent_frame_idx = current_frame_idx + 1;
580 parent_frame_idx < num_frames; ++parent_frame_idx) {
581 parent_frame = thread->GetStackFrameAtIndex(parent_frame_idx);
582 // Require a valid sequence of frames.
583 if (!parent_frame)
584 break;
585
586 // Record the first valid return address, even if this is an inlined frame,
587 // in order to look up the associated call edge in the first non-inlined
588 // parent frame.
589 if (return_pc == LLDB_INVALID_ADDRESS(18446744073709551615UL)) {
590 return_pc = parent_frame->GetFrameCodeAddress().GetLoadAddress(&target);
591 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)
592 "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)
593 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)
;
594 }
595
596 // If we've found an inlined frame, skip it (these have no call site
597 // parameters).
598 if (parent_frame->IsInlined())
599 continue;
600
601 // We've found the first non-inlined parent frame.
602 break;
603 }
604 if (!parent_frame || !parent_frame->GetRegisterContext()) {
605 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)
;
606 return false;
607 }
608
609 Function *parent_func =
610 parent_frame->GetSymbolContext(eSymbolContextFunction).function;
611 if (!parent_func) {
612 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)
;
613 return false;
614 }
615
616 // 2. Find the call edge in the parent function responsible for creating the
617 // current activation.
618 Function *current_func =
619 current_frame->GetSymbolContext(eSymbolContextFunction).function;
620 if (!current_func) {
621 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)
;
622 return false;
623 }
624
625 CallEdge *call_edge = nullptr;
626 ModuleList &modlist = target.GetImages();
627 ExecutionContext parent_exe_ctx = *exe_ctx;
628 parent_exe_ctx.SetFrameSP(parent_frame);
629 if (!parent_frame->IsArtificial()) {
630 // If the parent frame is not artificial, the current activation may be
631 // produced by an ambiguous tail call. In this case, refuse to proceed.
632 call_edge = parent_func->GetCallEdgeForReturnAddress(return_pc, target);
633 if (!call_edge) {
634 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)
635 "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)
636 "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)
637 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)
;
638 return false;
639 }
640 Function *callee_func = call_edge->GetCallee(modlist, parent_exe_ctx);
641 if (callee_func != current_func) {
642 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)
643 "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)
;
644 return false;
645 }
646 } else {
647 // The StackFrameList solver machinery has deduced that an unambiguous tail
648 // call sequence that produced the current activation. The first edge in
649 // the parent that points to the current function must be valid.
650 for (auto &edge : parent_func->GetTailCallingEdges()) {
651 if (edge->GetCallee(modlist, parent_exe_ctx) == current_func) {
652 call_edge = edge.get();
653 break;
654 }
655 }
656 }
657 if (!call_edge) {
658 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)
659 "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)
;
660 return false;
661 }
662
663 // 3. Attempt to locate the DW_OP_entry_value expression in the set of
664 // available call site parameters. If found, evaluate the corresponding
665 // parameter in the context of the parent frame.
666 const uint32_t subexpr_len = opcodes.GetULEB128(&opcode_offset);
667 const void *subexpr_data = opcodes.GetData(&opcode_offset, subexpr_len);
668 if (!subexpr_data) {
669 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)
;
670 return false;
671 }
672
673 const CallSiteParameter *matched_param = nullptr;
674 for (const CallSiteParameter &param : call_edge->GetCallSiteParameters()) {
675 DataExtractor param_subexpr_extractor;
676 if (!param.LocationInCallee.GetExpressionData(param_subexpr_extractor))
677 continue;
678 lldb::offset_t param_subexpr_offset = 0;
679 const void *param_subexpr_data =
680 param_subexpr_extractor.GetData(&param_subexpr_offset, subexpr_len);
681 if (!param_subexpr_data ||
682 param_subexpr_extractor.BytesLeft(param_subexpr_offset) != 0)
683 continue;
684
685 // At this point, the DW_OP_entry_value sub-expression and the callee-side
686 // expression in the call site parameter are known to have the same length.
687 // Check whether they are equal.
688 //
689 // Note that an equality check is sufficient: the contents of the
690 // DW_OP_entry_value subexpression are only used to identify the right call
691 // site parameter in the parent, and do not require any special handling.
692 if (memcmp(subexpr_data, param_subexpr_data, subexpr_len) == 0) {
693 matched_param = &param;
694 break;
695 }
696 }
697 if (!matched_param) {
698 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)
699 "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)
;
700 return false;
701 }
702
703 // TODO: Add support for DW_OP_push_object_address within a DW_OP_entry_value
704 // subexpresion whenever llvm does.
705 Value result;
706 const DWARFExpressionList &param_expr = matched_param->LocationInCaller;
707 if (!param_expr.Evaluate(&parent_exe_ctx,
708 parent_frame->GetRegisterContext().get(),
709 LLDB_INVALID_ADDRESS(18446744073709551615UL),
710 /*initial_value_ptr=*/nullptr,
711 /*object_address_ptr=*/nullptr, result, error_ptr)) {
712 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)
713 "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)
;
714 return false;
715 }
716
717 stack.push_back(result);
718 return true;
719}
720
721namespace {
722/// The location description kinds described by the DWARF v5
723/// specification. Composite locations are handled out-of-band and
724/// thus aren't part of the enum.
725enum LocationDescriptionKind {
726 Empty,
727 Memory,
728 Register,
729 Implicit
730 /* Composite*/
731};
732/// Adjust value's ValueType according to the kind of location description.
733void UpdateValueTypeFromLocationDescription(Log *log, const DWARFUnit *dwarf_cu,
734 LocationDescriptionKind kind,
735 Value *value = nullptr) {
736 // Note that this function is conflating DWARF expressions with
737 // DWARF location descriptions. Perhaps it would be better to define
738 // a wrapper for DWARFExpression::Eval() that deals with DWARF
739 // location descriptions (which consist of one or more DWARF
740 // expressions). But doing this would mean we'd also need factor the
741 // handling of DW_OP_(bit_)piece out of this function.
742 if (dwarf_cu && dwarf_cu->GetVersion() >= 4) {
743 const char *log_msg = "DWARF location description kind: %s";
744 switch (kind) {
745 case Empty:
746 LLDB_LOGF(log, log_msg, "Empty")do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf(log_msg, "Empty"); } while (0)
;
747 break;
748 case Memory:
749 LLDB_LOGF(log, log_msg, "Memory")do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf(log_msg, "Memory"); } while (0)
;
750 if (value->GetValueType() == Value::ValueType::Scalar)
751 value->SetValueType(Value::ValueType::LoadAddress);
752 break;
753 case Register:
754 LLDB_LOGF(log, log_msg, "Register")do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf(log_msg, "Register"); } while (0)
;
755 value->SetValueType(Value::ValueType::Scalar);
756 break;
757 case Implicit:
758 LLDB_LOGF(log, log_msg, "Implicit")do { ::lldb_private::Log *log_private = (log); if (log_private
) log_private->Printf(log_msg, "Implicit"); } while (0)
;
759 if (value->GetValueType() == Value::ValueType::LoadAddress)
760 value->SetValueType(Value::ValueType::Scalar);
761 break;
762 }
763 }
764}
765} // namespace
766
767/// Helper function to move common code used to resolve a file address and turn
768/// into a load address.
769///
770/// \param exe_ctx Pointer to the execution context
771/// \param module_sp shared_ptr contains the module if we have one
772/// \param error_ptr pointer to Status object if we have one
773/// \param dw_op_type C-style string used to vary the error output
774/// \param file_addr the file address we are trying to resolve and turn into a
775/// load address
776/// \param so_addr out parameter, will be set to load address or section offset
777/// \param check_sectionoffset bool which determines if having a section offset
778/// but not a load address is considerd a success
779/// \returns llvm::Optional containing the load address if resolving and getting
780/// the load address succeed or an empty Optinal otherwise. If
781/// check_sectionoffset is true we consider LLDB_INVALID_ADDRESS a
782/// success if so_addr.IsSectionOffset() is true.
783static llvm::Optional<lldb::addr_t>
784ResolveLoadAddress(ExecutionContext *exe_ctx, lldb::ModuleSP &module_sp,
785 Status *error_ptr, const char *dw_op_type,
786 lldb::addr_t file_addr, Address &so_addr,
787 bool check_sectionoffset = false) {
788 if (!module_sp) {
789 if (error_ptr)
790 error_ptr->SetErrorStringWithFormat(
791 "need module to resolve file address for %s", dw_op_type);
792 return {};
793 }
794
795 if (!module_sp->ResolveFileAddress(file_addr, so_addr)) {
796 if (error_ptr)
797 error_ptr->SetErrorString("failed to resolve file address in module");
798 return {};
799 }
800
801 addr_t load_addr = so_addr.GetLoadAddress(exe_ctx->GetTargetPtr());
802
803 if (load_addr == LLDB_INVALID_ADDRESS(18446744073709551615UL) &&
804 (check_sectionoffset && !so_addr.IsSectionOffset())) {
805 if (error_ptr)
806 error_ptr->SetErrorString("failed to resolve load address");
807 return {};
808 }
809
810 return load_addr;
811}
812
813/// Helper function to move common code used to load sized data from a uint8_t
814/// buffer.
815///
816/// \param addr_bytes uint8_t buffer containg raw data
817/// \param size_addr_bytes how large is the underlying raw data
818/// \param byte_order what is the byter order of the underlyig data
819/// \param size How much of the underlying data we want to use
820/// \return The underlying data converted into a Scalar
821static Scalar DerefSizeExtractDataHelper(uint8_t *addr_bytes,
822 size_t size_addr_bytes,
823 ByteOrder byte_order, size_t size) {
824 DataExtractor addr_data(addr_bytes, size_addr_bytes, byte_order, size);
825
826 lldb::offset_t addr_data_offset = 0;
827 if (size <= 8)
828 return addr_data.GetMaxU64(&addr_data_offset, size);
829 else
830 return addr_data.GetAddress(&addr_data_offset);
831}
832
833bool DWARFExpression::Evaluate(
834 ExecutionContext *exe_ctx, RegisterContext *reg_ctx,
835 lldb::ModuleSP module_sp, const DataExtractor &opcodes,
836 const DWARFUnit *dwarf_cu, const lldb::RegisterKind reg_kind,
837 const Value *initial_value_ptr, const Value *object_address_ptr,
838 Value &result, Status *error_ptr) {
839
840 if (opcodes.GetByteSize() == 0) {
841 if (error_ptr)
842 error_ptr->SetErrorString(
843 "no location, value may have been optimized out");
844 return false;
845 }
846 std::vector<Value> stack;
847
848 Process *process = nullptr;
849 StackFrame *frame = nullptr;
850 Target *target = nullptr;
851
852 if (exe_ctx) {
853 process = exe_ctx->GetProcessPtr();
854 frame = exe_ctx->GetFramePtr();
855 target = exe_ctx->GetTargetPtr();
856 }
857 if (reg_ctx == nullptr && frame)
858 reg_ctx = frame->GetRegisterContext().get();
859
860 if (initial_value_ptr)
861 stack.push_back(*initial_value_ptr);
862
863 lldb::offset_t offset = 0;
864 Value tmp;
865 uint32_t reg_num;
866
867 /// Insertion point for evaluating multi-piece expression.
868 uint64_t op_piece_offset = 0;
869 Value pieces; // Used for DW_OP_piece
870
871 Log *log = GetLog(LLDBLog::Expressions);
872 // A generic type is "an integral type that has the size of an address and an
873 // unspecified signedness". For now, just use the signedness of the operand.
874 // TODO: Implement a real typed stack, and store the genericness of the value
875 // there.
876 auto to_generic = [&](auto v) {
877 bool is_signed = std::is_signed<decltype(v)>::value;
878 return Scalar(llvm::APSInt(
879 llvm::APInt(8 * opcodes.GetAddressByteSize(), v, is_signed),
880 !is_signed));
881 };
882
883 // The default kind is a memory location. This is updated by any
884 // operation that changes this, such as DW_OP_stack_value, and reset
885 // by composition operations like DW_OP_piece.
886 LocationDescriptionKind dwarf4_location_description_kind = Memory;
887
888 while (opcodes.ValidOffset(offset)) {
889 const lldb::offset_t op_offset = offset;
890 const uint8_t op = opcodes.GetU8(&offset);
891
892 if (log && log->GetVerbose()) {
893 size_t count = stack.size();
894 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)
895 (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)
;
896 for (size_t i = 0; i < count; ++i) {
897 StreamString new_value;
898 new_value.Printf("[%" PRIu64"l" "u" "]", (uint64_t)i);
899 stack[i].Dump(&new_value);
900 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)
;
901 }
902 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)
903 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)
;
904 }
905
906 switch (op) {
907 // The DW_OP_addr operation has a single operand that encodes a machine
908 // address and whose size is the size of an address on the target machine.
909 case DW_OP_addr:
910 stack.push_back(Scalar(opcodes.GetAddress(&offset)));
911 if (target &&
912 target->GetArchitecture().GetCore() == ArchSpec::eCore_wasm32) {
913 // wasm file sections aren't mapped into memory, therefore addresses can
914 // never point into a file section and are always LoadAddresses.
915 stack.back().SetValueType(Value::ValueType::LoadAddress);
916 } else {
917 stack.back().SetValueType(Value::ValueType::FileAddress);
918 // Convert the file address to a load address, so subsequent
919 // DWARF operators can operate on it.
920 if (frame)
921 stack.back().ConvertToLoadAddress(module_sp.get(),
922 frame->CalculateTarget().get());
923 }
924 break;
925
926 // The DW_OP_addr_sect_offset4 is used for any location expressions in
927 // shared libraries that have a location like:
928 // DW_OP_addr(0x1000)
929 // If this address resides in a shared library, then this virtual address
930 // won't make sense when it is evaluated in the context of a running
931 // process where shared libraries have been slid. To account for this, this
932 // new address type where we can store the section pointer and a 4 byte
933 // offset.
934 // case DW_OP_addr_sect_offset4:
935 // {
936 // result_type = eResultTypeFileAddress;
937 // lldb::Section *sect = (lldb::Section
938 // *)opcodes.GetMaxU64(&offset, sizeof(void *));
939 // lldb::addr_t sect_offset = opcodes.GetU32(&offset);
940 //
941 // Address so_addr (sect, sect_offset);
942 // lldb::addr_t load_addr = so_addr.GetLoadAddress();
943 // if (load_addr != LLDB_INVALID_ADDRESS)
944 // {
945 // // We successfully resolve a file address to a load
946 // // address.
947 // stack.push_back(load_addr);
948 // break;
949 // }
950 // else
951 // {
952 // // We were able
953 // if (error_ptr)
954 // error_ptr->SetErrorStringWithFormat ("Section %s in
955 // %s is not currently loaded.\n",
956 // sect->GetName().AsCString(),
957 // sect->GetModule()->GetFileSpec().GetFilename().AsCString());
958 // return false;
959 // }
960 // }
961 // break;
962
963 // OPCODE: DW_OP_deref
964 // OPERANDS: none
965 // DESCRIPTION: Pops the top stack entry and treats it as an address.
966 // The value retrieved from that address is pushed. The size of the data
967 // retrieved from the dereferenced address is the size of an address on the
968 // target machine.
969 case DW_OP_deref: {
970 if (stack.empty()) {
971 if (error_ptr)
972 error_ptr->SetErrorString("Expression stack empty for DW_OP_deref.");
973 return false;
974 }
975 Value::ValueType value_type = stack.back().GetValueType();
976 switch (value_type) {
977 case Value::ValueType::HostAddress: {
978 void *src = (void *)stack.back().GetScalar().ULongLong();
979 intptr_t ptr;
980 ::memcpy(&ptr, src, sizeof(void *));
981 stack.back().GetScalar() = ptr;
982 stack.back().ClearContext();
983 } break;
984 case Value::ValueType::FileAddress: {
985 auto file_addr = stack.back().GetScalar().ULongLong(
986 LLDB_INVALID_ADDRESS(18446744073709551615UL));
987
988 Address so_addr;
989 auto maybe_load_addr = ResolveLoadAddress(
990 exe_ctx, module_sp, error_ptr, "DW_OP_deref", file_addr, so_addr);
991
992 if (!maybe_load_addr)
993 return false;
994
995 stack.back().GetScalar() = *maybe_load_addr;
996 // Fall through to load address promotion code below.
997 }
998 [[fallthrough]];
999 case Value::ValueType::Scalar:
1000 // Promote Scalar to LoadAddress and fall through.
1001 stack.back().SetValueType(Value::ValueType::LoadAddress);
1002 [[fallthrough]];
1003 case Value::ValueType::LoadAddress:
1004 if (exe_ctx) {
1005 if (process) {
1006 lldb::addr_t pointer_addr =
1007 stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS(18446744073709551615UL));
1008 Status error;
1009 lldb::addr_t pointer_value =
1010 process->ReadPointerFromMemory(pointer_addr, error);
1011 if (pointer_value != LLDB_INVALID_ADDRESS(18446744073709551615UL)) {
1012 if (ABISP abi_sp = process->GetABI())
1013 pointer_value = abi_sp->FixCodeAddress(pointer_value);
1014 stack.back().GetScalar() = pointer_value;
1015 stack.back().ClearContext();
1016 } else {
1017 if (error_ptr)
1018 error_ptr->SetErrorStringWithFormat(
1019 "Failed to dereference pointer from 0x%" PRIx64"l" "x"
1020 " for DW_OP_deref: %s\n",
1021 pointer_addr, error.AsCString());
1022 return false;
1023 }
1024 } else {
1025 if (error_ptr)
1026 error_ptr->SetErrorString("NULL process for DW_OP_deref.\n");
1027 return false;
1028 }
1029 } else {
1030 if (error_ptr)
1031 error_ptr->SetErrorString(
1032 "NULL execution context for DW_OP_deref.\n");
1033 return false;
1034 }
1035 break;
1036
1037 case Value::ValueType::Invalid:
1038 if (error_ptr)
1039 error_ptr->SetErrorString("Invalid value type for DW_OP_deref.\n");
1040 return false;
1041 }
1042
1043 } break;
1044
1045 // OPCODE: DW_OP_deref_size
1046 // OPERANDS: 1
1047 // 1 - uint8_t that specifies the size of the data to dereference.
1048 // DESCRIPTION: Behaves like the DW_OP_deref operation: it pops the top
1049 // stack entry and treats it as an address. The value retrieved from that
1050 // address is pushed. In the DW_OP_deref_size operation, however, the size
1051 // in bytes of the data retrieved from the dereferenced address is
1052 // specified by the single operand. This operand is a 1-byte unsigned
1053 // integral constant whose value may not be larger than the size of an
1054 // address on the target machine. The data retrieved is zero extended to
1055 // the size of an address on the target machine before being pushed on the
1056 // expression stack.
1057 case DW_OP_deref_size: {
1058 if (stack.empty()) {
1059 if (error_ptr)
1060 error_ptr->SetErrorString(
1061 "Expression stack empty for DW_OP_deref_size.");
1062 return false;
1063 }
1064 uint8_t size = opcodes.GetU8(&offset);
1065 Value::ValueType value_type = stack.back().GetValueType();
1066 switch (value_type) {
1067 case Value::ValueType::HostAddress: {
1068 void *src = (void *)stack.back().GetScalar().ULongLong();
1069 intptr_t ptr;
1070 ::memcpy(&ptr, src, sizeof(void *));
1071 // I can't decide whether the size operand should apply to the bytes in
1072 // their
1073 // lldb-host endianness or the target endianness.. I doubt this'll ever
1074 // come up but I'll opt for assuming big endian regardless.
1075 switch (size) {
1076 case 1:
1077 ptr = ptr & 0xff;
1078 break;
1079 case 2:
1080 ptr = ptr & 0xffff;
1081 break;
1082 case 3:
1083 ptr = ptr & 0xffffff;
1084 break;
1085 case 4:
1086 ptr = ptr & 0xffffffff;
1087 break;
1088 // the casts are added to work around the case where intptr_t is a 32
1089 // bit quantity;
1090 // presumably we won't hit the 5..7 cases if (void*) is 32-bits in this
1091 // program.
1092 case 5:
1093 ptr = (intptr_t)ptr & 0xffffffffffULL;
1094 break;
1095 case 6:
1096 ptr = (intptr_t)ptr & 0xffffffffffffULL;
1097 break;
1098 case 7:
1099 ptr = (intptr_t)ptr & 0xffffffffffffffULL;
1100 break;
1101 default:
1102 break;
1103 }
1104 stack.back().GetScalar() = ptr;
1105 stack.back().ClearContext();
1106 } break;
1107 case Value::ValueType::FileAddress: {
1108 auto file_addr =
1109 stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS(18446744073709551615UL));
1110 Address so_addr;
1111 auto maybe_load_addr =
1112 ResolveLoadAddress(exe_ctx, module_sp, error_ptr,
1113 "DW_OP_deref_size", file_addr, so_addr,
1114 /*check_sectionoffset=*/true);
1115
1116 if (!maybe_load_addr)
1117 return false;
1118
1119 addr_t load_addr = *maybe_load_addr;
1120
1121 if (load_addr == LLDB_INVALID_ADDRESS(18446744073709551615UL) && so_addr.IsSectionOffset()) {
1122 uint8_t addr_bytes[8];
1123 Status error;
1124
1125 if (exe_ctx->GetTargetRef().ReadMemory(
1126 so_addr, &addr_bytes, size, error,
1127 /*force_live_memory=*/false) == size) {
1128 ObjectFile *objfile = module_sp->GetObjectFile();
1129
1130 stack.back().GetScalar() = DerefSizeExtractDataHelper(
1131 addr_bytes, size, objfile->GetByteOrder(), size);
1132 stack.back().ClearContext();
1133 break;
1134 } else {
1135 if (error_ptr)
1136 error_ptr->SetErrorStringWithFormat(
1137 "Failed to dereference pointer for for DW_OP_deref_size: "
1138 "%s\n",
1139 error.AsCString());
1140 return false;
1141 }
1142 }
1143 stack.back().GetScalar() = load_addr;
1144 // Fall through to load address promotion code below.
1145 }
1146
1147 [[fallthrough]];
1148 case Value::ValueType::Scalar:
1149 case Value::ValueType::LoadAddress:
1150 if (exe_ctx) {
1151 if (process) {
1152 lldb::addr_t pointer_addr =
1153 stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS(18446744073709551615UL));
1154 uint8_t addr_bytes[sizeof(lldb::addr_t)];
1155 Status error;
1156 if (process->ReadMemory(pointer_addr, &addr_bytes, size, error) ==
1157 size) {
1158
1159 stack.back().GetScalar() =
1160 DerefSizeExtractDataHelper(addr_bytes, sizeof(addr_bytes),
1161 process->GetByteOrder(), size);
1162 stack.back().ClearContext();
1163 } else {
1164 if (error_ptr)
1165 error_ptr->SetErrorStringWithFormat(
1166 "Failed to dereference pointer from 0x%" PRIx64"l" "x"
1167 " for DW_OP_deref: %s\n",
1168 pointer_addr, error.AsCString());
1169 return false;
1170 }
1171 } else {
1172 if (error_ptr)
1173 error_ptr->SetErrorString("NULL process for DW_OP_deref_size.\n");
1174 return false;
1175 }
1176 } else {
1177 if (error_ptr)
1178 error_ptr->SetErrorString(
1179 "NULL execution context for DW_OP_deref_size.\n");
1180 return false;
1181 }
1182 break;
1183
1184 case Value::ValueType::Invalid:
1185 if (error_ptr)
1186 error_ptr->SetErrorString("Invalid value for DW_OP_deref_size.\n");
1187 return false;
1188 }
1189
1190 } break;
1191
1192 // OPCODE: DW_OP_xderef_size
1193 // OPERANDS: 1
1194 // 1 - uint8_t that specifies the size of the data to dereference.
1195 // DESCRIPTION: Behaves like the DW_OP_xderef operation: the entry at
1196 // the top of the stack is treated as an address. The second stack entry is
1197 // treated as an "address space identifier" for those architectures that
1198 // support multiple address spaces. The top two stack elements are popped,
1199 // a data item is retrieved through an implementation-defined address
1200 // calculation and pushed as the new stack top. In the DW_OP_xderef_size
1201 // operation, however, the size in bytes of the data retrieved from the
1202 // dereferenced address is specified by the single operand. This operand is
1203 // a 1-byte unsigned integral constant whose value may not be larger than
1204 // the size of an address on the target machine. The data retrieved is zero
1205 // extended to the size of an address on the target machine before being
1206 // pushed on the expression stack.
1207 case DW_OP_xderef_size:
1208 if (error_ptr)
1209 error_ptr->SetErrorString("Unimplemented opcode: DW_OP_xderef_size.");
1210 return false;
1211 // OPCODE: DW_OP_xderef
1212 // OPERANDS: none
1213 // DESCRIPTION: Provides an extended dereference mechanism. 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. The size of the data
1219 // retrieved from the dereferenced address is the size of an address on the
1220 // target machine.
1221 case DW_OP_xderef:
1222 if (error_ptr)
1223 error_ptr->SetErrorString("Unimplemented opcode: DW_OP_xderef.");
1224 return false;
1225
1226 // All DW_OP_constXXX opcodes have a single operand as noted below:
1227 //
1228 // Opcode Operand 1
1229 // DW_OP_const1u 1-byte unsigned integer constant
1230 // DW_OP_const1s 1-byte signed integer constant
1231 // DW_OP_const2u 2-byte unsigned integer constant
1232 // DW_OP_const2s 2-byte signed integer constant
1233 // DW_OP_const4u 4-byte unsigned integer constant
1234 // DW_OP_const4s 4-byte signed integer constant
1235 // DW_OP_const8u 8-byte unsigned integer constant
1236 // DW_OP_const8s 8-byte signed integer constant
1237 // DW_OP_constu unsigned LEB128 integer constant
1238 // DW_OP_consts signed LEB128 integer constant
1239 case DW_OP_const1u:
1240 stack.push_back(to_generic(opcodes.GetU8(&offset)));
1241 break;
1242 case DW_OP_const1s:
1243 stack.push_back(to_generic((int8_t)opcodes.GetU8(&offset)));
1244 break;
1245 case DW_OP_const2u:
1246 stack.push_back(to_generic(opcodes.GetU16(&offset)));
1247 break;
1248 case DW_OP_const2s:
1249 stack.push_back(to_generic((int16_t)opcodes.GetU16(&offset)));
1250 break;
1251 case DW_OP_const4u:
1252 stack.push_back(to_generic(opcodes.GetU32(&offset)));
1253 break;
1254 case DW_OP_const4s:
1255 stack.push_back(to_generic((int32_t)opcodes.GetU32(&offset)));
1256 break;
1257 case DW_OP_const8u:
1258 stack.push_back(to_generic(opcodes.GetU64(&offset)));
1259 break;
1260 case DW_OP_const8s:
1261 stack.push_back(to_generic((int64_t)opcodes.GetU64(&offset)));
1262 break;
1263 // These should also use to_generic, but we can't do that due to a
1264 // producer-side bug in llvm. See llvm.org/pr48087.
1265 case DW_OP_constu:
1266 stack.push_back(Scalar(opcodes.GetULEB128(&offset)));
1267 break;
1268 case DW_OP_consts:
1269 stack.push_back(Scalar(opcodes.GetSLEB128(&offset)));
1270 break;
1271
1272 // OPCODE: DW_OP_dup
1273 // OPERANDS: none
1274 // DESCRIPTION: duplicates the value at the top of the stack
1275 case DW_OP_dup:
1276 if (stack.empty()) {
1277 if (error_ptr)
1278 error_ptr->SetErrorString("Expression stack empty for DW_OP_dup.");
1279 return false;
1280 } else
1281 stack.push_back(stack.back());
1282 break;
1283
1284 // OPCODE: DW_OP_drop
1285 // OPERANDS: none
1286 // DESCRIPTION: pops the value at the top of the stack
1287 case DW_OP_drop:
1288 if (stack.empty()) {
1289 if (error_ptr)
1290 error_ptr->SetErrorString("Expression stack empty for DW_OP_drop.");
1291 return false;
1292 } else
1293 stack.pop_back();
1294 break;
1295
1296 // OPCODE: DW_OP_over
1297 // OPERANDS: none
1298 // DESCRIPTION: Duplicates the entry currently second in the stack at
1299 // the top of the stack.
1300 case DW_OP_over:
1301 if (stack.size() < 2) {
1302 if (error_ptr)
1303 error_ptr->SetErrorString(
1304 "Expression stack needs at least 2 items for DW_OP_over.");
1305 return false;
1306 } else
1307 stack.push_back(stack[stack.size() - 2]);
1308 break;
1309
1310 // OPCODE: DW_OP_pick
1311 // OPERANDS: uint8_t index into the current stack
1312 // DESCRIPTION: The stack entry with the specified index (0 through 255,
1313 // inclusive) is pushed on the stack
1314 case DW_OP_pick: {
1315 uint8_t pick_idx = opcodes.GetU8(&offset);
1316 if (pick_idx < stack.size())
1317 stack.push_back(stack[stack.size() - 1 - pick_idx]);
1318 else {
1319 if (error_ptr)
1320 error_ptr->SetErrorStringWithFormat(
1321 "Index %u out of range for DW_OP_pick.\n", pick_idx);
1322 return false;
1323 }
1324 } break;
1325
1326 // OPCODE: DW_OP_swap
1327 // OPERANDS: none
1328 // DESCRIPTION: swaps the top two stack entries. The entry at the top
1329 // of the stack becomes the second stack entry, and the second entry
1330 // becomes the top of the stack
1331 case DW_OP_swap:
1332 if (stack.size() < 2) {
1333 if (error_ptr)
1334 error_ptr->SetErrorString(
1335 "Expression stack needs at least 2 items for DW_OP_swap.");
1336 return false;
1337 } else {
1338 tmp = stack.back();
1339 stack.back() = stack[stack.size() - 2];
1340 stack[stack.size() - 2] = tmp;
1341 }
1342 break;
1343
1344 // OPCODE: DW_OP_rot
1345 // OPERANDS: none
1346 // DESCRIPTION: Rotates the first three stack entries. The entry at
1347 // the top of the stack becomes the third stack entry, the second entry
1348 // becomes the top of the stack, and the third entry becomes the second
1349 // entry.
1350 case DW_OP_rot:
1351 if (stack.size() < 3) {
1352 if (error_ptr)
1353 error_ptr->SetErrorString(
1354 "Expression stack needs at least 3 items for DW_OP_rot.");
1355 return false;
1356 } else {
1357 size_t last_idx = stack.size() - 1;
1358 Value old_top = stack[last_idx];
1359 stack[last_idx] = stack[last_idx - 1];
1360 stack[last_idx - 1] = stack[last_idx - 2];
1361 stack[last_idx - 2] = old_top;
1362 }
1363 break;
1364
1365 // OPCODE: DW_OP_abs
1366 // OPERANDS: none
1367 // DESCRIPTION: pops the top stack entry, interprets it as a signed
1368 // value and pushes its absolute value. If the absolute value can not be
1369 // represented, the result is undefined.
1370 case DW_OP_abs:
1371 if (stack.empty()) {
1372 if (error_ptr)
1373 error_ptr->SetErrorString(
1374 "Expression stack needs at least 1 item for DW_OP_abs.");
1375 return false;
1376 } else if (!stack.back().ResolveValue(exe_ctx).AbsoluteValue()) {
1377 if (error_ptr)
1378 error_ptr->SetErrorString(
1379 "Failed to take the absolute value of the first stack item.");
1380 return false;
1381 }
1382 break;
1383
1384 // OPCODE: DW_OP_and
1385 // OPERANDS: none
1386 // DESCRIPTION: pops the top two stack values, performs a bitwise and
1387 // operation on the two, and pushes the result.
1388 case DW_OP_and:
1389 if (stack.size() < 2) {
1390 if (error_ptr)
1391 error_ptr->SetErrorString(
1392 "Expression stack needs at least 2 items for DW_OP_and.");
1393 return false;
1394 } else {
1395 tmp = stack.back();
1396 stack.pop_back();
1397 stack.back().ResolveValue(exe_ctx) =
1398 stack.back().ResolveValue(exe_ctx) & tmp.ResolveValue(exe_ctx);
1399 }
1400 break;
1401
1402 // OPCODE: DW_OP_div
1403 // OPERANDS: none
1404 // DESCRIPTION: pops the top two stack values, divides the former second
1405 // entry by the former top of the stack using signed division, and pushes
1406 // the result.
1407 case DW_OP_div:
1408 if (stack.size() < 2) {
1409 if (error_ptr)
1410 error_ptr->SetErrorString(
1411 "Expression stack needs at least 2 items for DW_OP_div.");
1412 return false;
1413 } else {
1414 tmp = stack.back();
1415 if (tmp.ResolveValue(exe_ctx).IsZero()) {
1416 if (error_ptr)
1417 error_ptr->SetErrorString("Divide by zero.");
1418 return false;
1419 } else {
1420 stack.pop_back();
1421 stack.back() =
1422 stack.back().ResolveValue(exe_ctx) / tmp.ResolveValue(exe_ctx);
1423 if (!stack.back().ResolveValue(exe_ctx).IsValid()) {
1424 if (error_ptr)
1425 error_ptr->SetErrorString("Divide failed.");
1426 return false;
1427 }
1428 }
1429 }
1430 break;
1431
1432 // OPCODE: DW_OP_minus
1433 // OPERANDS: none
1434 // DESCRIPTION: pops the top two stack values, subtracts the former top
1435 // of the stack from the former second entry, and pushes the result.
1436 case DW_OP_minus:
1437 if (stack.size() < 2) {
1438 if (error_ptr)
1439 error_ptr->SetErrorString(
1440 "Expression stack needs at least 2 items for DW_OP_minus.");
1441 return false;
1442 } else {
1443 tmp = stack.back();
1444 stack.pop_back();
1445 stack.back().ResolveValue(exe_ctx) =
1446 stack.back().ResolveValue(exe_ctx) - tmp.ResolveValue(exe_ctx);
1447 }
1448 break;
1449
1450 // OPCODE: DW_OP_mod
1451 // OPERANDS: none
1452 // DESCRIPTION: pops the top two stack values and pushes the result of
1453 // the calculation: former second stack entry modulo the former top of the
1454 // stack.
1455 case DW_OP_mod:
1456 if (stack.size() < 2) {
1457 if (error_ptr)
1458 error_ptr->SetErrorString(
1459 "Expression stack needs at least 2 items for DW_OP_mod.");
1460 return false;
1461 } else {
1462 tmp = stack.back();
1463 stack.pop_back();
1464 stack.back().ResolveValue(exe_ctx) =
1465 stack.back().ResolveValue(exe_ctx) % tmp.ResolveValue(exe_ctx);
1466 }
1467 break;
1468
1469 // OPCODE: DW_OP_mul
1470 // OPERANDS: none
1471 // DESCRIPTION: pops the top two stack entries, multiplies them
1472 // together, and pushes the result.
1473 case DW_OP_mul:
1474 if (stack.size() < 2) {
1475 if (error_ptr)
1476 error_ptr->SetErrorString(
1477 "Expression stack needs at least 2 items for DW_OP_mul.");
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_neg
1488 // OPERANDS: none
1489 // DESCRIPTION: pops the top stack entry, and pushes its negation.
1490 case DW_OP_neg:
1491 if (stack.empty()) {
1492 if (error_ptr)
1493 error_ptr->SetErrorString(
1494 "Expression stack needs at least 1 item for DW_OP_neg.");
1495 return false;
1496 } else {
1497 if (!stack.back().ResolveValue(exe_ctx).UnaryNegate()) {
1498 if (error_ptr)
1499 error_ptr->SetErrorString("Unary negate failed.");
1500 return false;
1501 }
1502 }
1503 break;
1504
1505 // OPCODE: DW_OP_not
1506 // OPERANDS: none
1507 // DESCRIPTION: pops the top stack entry, and pushes its bitwise
1508 // complement
1509 case DW_OP_not:
1510 if (stack.empty()) {
1511 if (error_ptr)
1512 error_ptr->SetErrorString(
1513 "Expression stack needs at least 1 item for DW_OP_not.");
1514 return false;
1515 } else {
1516 if (!stack.back().ResolveValue(exe_ctx).OnesComplement()) {
1517 if (error_ptr)
1518 error_ptr->SetErrorString("Logical NOT failed.");
1519 return false;
1520 }
1521 }
1522 break;
1523
1524 // OPCODE: DW_OP_or
1525 // OPERANDS: none
1526 // DESCRIPTION: pops the top two stack entries, performs a bitwise or
1527 // operation on the two, and pushes the result.
1528 case DW_OP_or:
1529 if (stack.size() < 2) {
1530 if (error_ptr)
1531 error_ptr->SetErrorString(
1532 "Expression stack needs at least 2 items for DW_OP_or.");
1533 return false;
1534 } else {
1535 tmp = stack.back();
1536 stack.pop_back();
1537 stack.back().ResolveValue(exe_ctx) =
1538 stack.back().ResolveValue(exe_ctx) | tmp.ResolveValue(exe_ctx);
1539 }
1540 break;
1541
1542 // OPCODE: DW_OP_plus
1543 // OPERANDS: none
1544 // DESCRIPTION: pops the top two stack entries, adds them together, and
1545 // pushes the result.
1546 case DW_OP_plus:
1547 if (stack.size() < 2) {
1548 if (error_ptr)
1549 error_ptr->SetErrorString(
1550 "Expression stack needs at least 2 items for DW_OP_plus.");
1551 return false;
1552 } else {
1553 tmp = stack.back();
1554 stack.pop_back();
1555 stack.back().GetScalar() += tmp.GetScalar();
1556 }
1557 break;
1558
1559 // OPCODE: DW_OP_plus_uconst
1560 // OPERANDS: none
1561 // DESCRIPTION: pops the top stack entry, adds it to the unsigned LEB128
1562 // constant operand and pushes the result.
1563 case DW_OP_plus_uconst:
1564 if (stack.empty()) {
1565 if (error_ptr)
1566 error_ptr->SetErrorString(
1567 "Expression stack needs at least 1 item for DW_OP_plus_uconst.");
1568 return false;
1569 } else {
1570 const uint64_t uconst_value = opcodes.GetULEB128(&offset);
1571 // Implicit conversion from a UINT to a Scalar...
1572 stack.back().GetScalar() += uconst_value;
1573 if (!stack.back().GetScalar().IsValid()) {
1574 if (error_ptr)
1575 error_ptr->SetErrorString("DW_OP_plus_uconst failed.");
1576 return false;
1577 }
1578 }
1579 break;
1580
1581 // OPCODE: DW_OP_shl
1582 // OPERANDS: none
1583 // DESCRIPTION: pops the top two stack entries, shifts the former
1584 // second entry left by the number of bits specified by the former top of
1585 // the stack, and pushes the result.
1586 case DW_OP_shl:
1587 if (stack.size() < 2) {
1588 if (error_ptr)
1589 error_ptr->SetErrorString(
1590 "Expression stack needs at least 2 items for DW_OP_shl.");
1591 return false;
1592 } else {
1593 tmp = stack.back();
1594 stack.pop_back();
1595 stack.back().ResolveValue(exe_ctx) <<= tmp.ResolveValue(exe_ctx);
1596 }
1597 break;
1598
1599 // OPCODE: DW_OP_shr
1600 // OPERANDS: none
1601 // DESCRIPTION: pops the top two stack entries, shifts the former second
1602 // entry right logically (filling with zero bits) by the number of bits
1603 // specified by the former top of the stack, and pushes the result.
1604 case DW_OP_shr:
1605 if (stack.size() < 2) {
1606 if (error_ptr)
1607 error_ptr->SetErrorString(
1608 "Expression stack needs at least 2 items for DW_OP_shr.");
1609 return false;
1610 } else {
1611 tmp = stack.back();
1612 stack.pop_back();
1613 if (!stack.back().ResolveValue(exe_ctx).ShiftRightLogical(
1614 tmp.ResolveValue(exe_ctx))) {
1615 if (error_ptr)
1616 error_ptr->SetErrorString("DW_OP_shr failed.");
1617 return false;
1618 }
1619 }
1620 break;
1621
1622 // OPCODE: DW_OP_shra
1623 // OPERANDS: none
1624 // DESCRIPTION: pops the top two stack entries, shifts the former second
1625 // entry right arithmetically (divide the magnitude by 2, keep the same
1626 // sign for the result) by the number of bits specified by the former top
1627 // of the stack, and pushes the result.
1628 case DW_OP_shra:
1629 if (stack.size() < 2) {
1630 if (error_ptr)
1631 error_ptr->SetErrorString(
1632 "Expression stack needs at least 2 items for DW_OP_shra.");
1633 return false;
1634 } else {
1635 tmp = stack.back();
1636 stack.pop_back();
1637 stack.back().ResolveValue(exe_ctx) >>= tmp.ResolveValue(exe_ctx);
1638 }
1639 break;
1640
1641 // OPCODE: DW_OP_xor
1642 // OPERANDS: none
1643 // DESCRIPTION: pops the top two stack entries, performs the bitwise
1644 // exclusive-or operation on the two, and pushes the result.
1645 case DW_OP_xor:
1646 if (stack.size() < 2) {
1647 if (error_ptr)
1648 error_ptr->SetErrorString(
1649 "Expression stack needs at least 2 items for DW_OP_xor.");
1650 return false;
1651 } else {
1652 tmp = stack.back();
1653 stack.pop_back();
1654 stack.back().ResolveValue(exe_ctx) =
1655 stack.back().ResolveValue(exe_ctx) ^ tmp.ResolveValue(exe_ctx);
1656 }
1657 break;
1658
1659 // OPCODE: DW_OP_skip
1660 // OPERANDS: int16_t
1661 // DESCRIPTION: An unconditional branch. Its single operand is a 2-byte
1662 // signed integer constant. The 2-byte constant is the number of bytes of
1663 // the DWARF expression to skip forward or backward from the current
1664 // operation, beginning after the 2-byte constant.
1665 case DW_OP_skip: {
1666 int16_t skip_offset = (int16_t)opcodes.GetU16(&offset);
1667 lldb::offset_t new_offset = offset + skip_offset;
1668 // New offset can point at the end of the data, in this case we should
1669 // terminate the DWARF expression evaluation (will happen in the loop
1670 // condition).
1671 if (new_offset <= opcodes.GetByteSize())
1672 offset = new_offset;
1673 else {
1674 if (error_ptr)
1675 error_ptr->SetErrorStringWithFormatv(
1676 "Invalid opcode offset in DW_OP_skip: {0}+({1}) > {2}", offset,
1677 skip_offset, opcodes.GetByteSize());
1678 return false;
1679 }
1680 } break;
1681
1682 // OPCODE: DW_OP_bra
1683 // OPERANDS: int16_t
1684 // DESCRIPTION: A conditional branch. Its single operand is a 2-byte
1685 // signed integer constant. This operation pops the top of stack. If the
1686 // value popped is not the constant 0, the 2-byte constant operand is the
1687 // number of bytes of the DWARF expression to skip forward or backward from
1688 // the current operation, beginning after the 2-byte constant.
1689 case DW_OP_bra:
1690 if (stack.empty()) {
1691 if (error_ptr)
1692 error_ptr->SetErrorString(
1693 "Expression stack needs at least 1 item for DW_OP_bra.");
1694 return false;
1695 } else {
1696 tmp = stack.back();
1697 stack.pop_back();
1698 int16_t bra_offset = (int16_t)opcodes.GetU16(&offset);
1699 Scalar zero(0);
1700 if (tmp.ResolveValue(exe_ctx) != zero) {
1701 lldb::offset_t new_offset = offset + bra_offset;
1702 // New offset can point at the end of the data, in this case we should
1703 // terminate the DWARF expression evaluation (will happen in the loop
1704 // condition).
1705 if (new_offset <= opcodes.GetByteSize())
1706 offset = new_offset;
1707 else {
1708 if (error_ptr)
1709 error_ptr->SetErrorStringWithFormatv(
1710 "Invalid opcode offset in DW_OP_bra: {0}+({1}) > {2}", offset,
1711 bra_offset, opcodes.GetByteSize());
1712 return false;
1713 }
1714 }
1715 }
1716 break;
1717
1718 // OPCODE: DW_OP_eq
1719 // OPERANDS: none
1720 // DESCRIPTION: pops the top two stack values, compares using the
1721 // equals (==) operator.
1722 // STACK RESULT: push the constant value 1 onto the stack if the result
1723 // of the operation is true or the constant value 0 if the result of the
1724 // operation is false.
1725 case DW_OP_eq:
1726 if (stack.size() < 2) {
1727 if (error_ptr)
1728 error_ptr->SetErrorString(
1729 "Expression stack needs at least 2 items for DW_OP_eq.");
1730 return false;
1731 } else {
1732 tmp = stack.back();
1733 stack.pop_back();
1734 stack.back().ResolveValue(exe_ctx) =
1735 stack.back().ResolveValue(exe_ctx) == tmp.ResolveValue(exe_ctx);
1736 }
1737 break;
1738
1739 // OPCODE: DW_OP_ge
1740 // OPERANDS: none
1741 // DESCRIPTION: pops the top two stack values, compares using the
1742 // greater than or equal to (>=) operator.
1743 // STACK RESULT: push the constant value 1 onto the stack if the result
1744 // of the operation is true or the constant value 0 if the result of the
1745 // operation is false.
1746 case DW_OP_ge:
1747 if (stack.size() < 2) {
1748 if (error_ptr)
1749 error_ptr->SetErrorString(
1750 "Expression stack needs at least 2 items for DW_OP_ge.");
1751 return false;
1752 } else {
1753 tmp = stack.back();
1754 stack.pop_back();
1755 stack.back().ResolveValue(exe_ctx) =
1756 stack.back().ResolveValue(exe_ctx) >= tmp.ResolveValue(exe_ctx);
1757 }
1758 break;
1759
1760 // OPCODE: DW_OP_gt
1761 // OPERANDS: none
1762 // DESCRIPTION: pops the top two stack values, compares using the
1763 // greater than (>) operator.
1764 // STACK RESULT: push the constant value 1 onto the stack if the result
1765 // of the operation is true or the constant value 0 if the result of the
1766 // operation is false.
1767 case DW_OP_gt:
1768 if (stack.size() < 2) {
1769 if (error_ptr)
1770 error_ptr->SetErrorString(
1771 "Expression stack needs at least 2 items for DW_OP_gt.");
1772 return false;
1773 } else {
1774 tmp = stack.back();
1775 stack.pop_back();
1776 stack.back().ResolveValue(exe_ctx) =
1777 stack.back().ResolveValue(exe_ctx) > tmp.ResolveValue(exe_ctx);
1778 }
1779 break;
1780
1781 // OPCODE: DW_OP_le
1782 // OPERANDS: none
1783 // DESCRIPTION: pops the top two stack values, compares using the
1784 // less than or equal to (<=) operator.
1785 // STACK RESULT: push the constant value 1 onto the stack if the result
1786 // of the operation is true or the constant value 0 if the result of the
1787 // operation is false.
1788 case DW_OP_le:
1789 if (stack.size() < 2) {
1790 if (error_ptr)
1791 error_ptr->SetErrorString(
1792 "Expression stack needs at least 2 items for DW_OP_le.");
1793 return false;
1794 } else {
1795 tmp = stack.back();
1796 stack.pop_back();
1797 stack.back().ResolveValue(exe_ctx) =
1798 stack.back().ResolveValue(exe_ctx) <= tmp.ResolveValue(exe_ctx);
1799 }
1800 break;
1801
1802 // OPCODE: DW_OP_lt
1803 // OPERANDS: none
1804 // DESCRIPTION: pops the top two stack values, compares using the
1805 // less than (<) operator.
1806 // STACK RESULT: push the constant value 1 onto the stack if the result
1807 // of the operation is true or the constant value 0 if the result of the
1808 // operation is false.
1809 case DW_OP_lt:
1810 if (stack.size() < 2) {
1811 if (error_ptr)
1812 error_ptr->SetErrorString(
1813 "Expression stack needs at least 2 items for DW_OP_lt.");
1814 return false;
1815 } else {
1816 tmp = stack.back();
1817 stack.pop_back();
1818 stack.back().ResolveValue(exe_ctx) =
1819 stack.back().ResolveValue(exe_ctx) < tmp.ResolveValue(exe_ctx);
1820 }
1821 break;
1822
1823 // OPCODE: DW_OP_ne
1824 // OPERANDS: none
1825 // DESCRIPTION: pops the top two stack values, compares using the
1826 // not equal (!=) operator.
1827 // STACK RESULT: push the constant value 1 onto the stack if the result
1828 // of the operation is true or the constant value 0 if the result of the
1829 // operation is false.
1830 case DW_OP_ne:
1831 if (stack.size() < 2) {
1832 if (error_ptr)
1833 error_ptr->SetErrorString(
1834 "Expression stack needs at least 2 items for DW_OP_ne.");
1835 return false;
1836 } else {
1837 tmp = stack.back();
1838 stack.pop_back();
1839 stack.back().ResolveValue(exe_ctx) =
1840 stack.back().ResolveValue(exe_ctx) != tmp.ResolveValue(exe_ctx);
1841 }
1842 break;
1843
1844 // OPCODE: DW_OP_litn
1845 // OPERANDS: none
1846 // DESCRIPTION: encode the unsigned literal values from 0 through 31.
1847 // STACK RESULT: push the unsigned literal constant value onto the top
1848 // of the stack.
1849 case DW_OP_lit0:
1850 case DW_OP_lit1:
1851 case DW_OP_lit2:
1852 case DW_OP_lit3:
1853 case DW_OP_lit4:
1854 case DW_OP_lit5:
1855 case DW_OP_lit6:
1856 case DW_OP_lit7:
1857 case DW_OP_lit8:
1858 case DW_OP_lit9:
1859 case DW_OP_lit10:
1860 case DW_OP_lit11:
1861 case DW_OP_lit12:
1862 case DW_OP_lit13:
1863 case DW_OP_lit14:
1864 case DW_OP_lit15:
1865 case DW_OP_lit16:
1866 case DW_OP_lit17:
1867 case DW_OP_lit18:
1868 case DW_OP_lit19:
1869 case DW_OP_lit20:
1870 case DW_OP_lit21:
1871 case DW_OP_lit22:
1872 case DW_OP_lit23:
1873 case DW_OP_lit24:
1874 case DW_OP_lit25:
1875 case DW_OP_lit26:
1876 case DW_OP_lit27:
1877 case DW_OP_lit28:
1878 case DW_OP_lit29:
1879 case DW_OP_lit30:
1880 case DW_OP_lit31:
1881 stack.push_back(to_generic(op - DW_OP_lit0));
1882 break;
1883
1884 // OPCODE: DW_OP_regN
1885 // OPERANDS: none
1886 // DESCRIPTION: Push the value in register n on the top of the stack.
1887 case DW_OP_reg0:
1888 case DW_OP_reg1:
1889 case DW_OP_reg2:
1890 case DW_OP_reg3:
1891 case DW_OP_reg4:
1892 case DW_OP_reg5:
1893 case DW_OP_reg6:
1894 case DW_OP_reg7:
1895 case DW_OP_reg8:
1896 case DW_OP_reg9:
1897 case DW_OP_reg10:
1898 case DW_OP_reg11:
1899 case DW_OP_reg12:
1900 case DW_OP_reg13:
1901 case DW_OP_reg14:
1902 case DW_OP_reg15:
1903 case DW_OP_reg16:
1904 case DW_OP_reg17:
1905 case DW_OP_reg18:
1906 case DW_OP_reg19:
1907 case DW_OP_reg20:
1908 case DW_OP_reg21:
1909 case DW_OP_reg22:
1910 case DW_OP_reg23:
1911 case DW_OP_reg24:
1912 case DW_OP_reg25:
1913 case DW_OP_reg26:
1914 case DW_OP_reg27:
1915 case DW_OP_reg28:
1916 case DW_OP_reg29:
1917 case DW_OP_reg30:
1918 case DW_OP_reg31: {
1919 dwarf4_location_description_kind = Register;
1920 reg_num = op - DW_OP_reg0;
1921
1922 if (ReadRegisterValueAsScalar(reg_ctx, reg_kind, reg_num, error_ptr, tmp))
1923 stack.push_back(tmp);
1924 else
1925 return false;
1926 } break;
1927 // OPCODE: DW_OP_regx
1928 // OPERANDS:
1929 // ULEB128 literal operand that encodes the register.
1930 // DESCRIPTION: Push the value in register on the top of the stack.
1931 case DW_OP_regx: {
1932 dwarf4_location_description_kind = Register;
1933 reg_num = opcodes.GetULEB128(&offset);
1934 if (ReadRegisterValueAsScalar(reg_ctx, reg_kind, reg_num, error_ptr, tmp))
1935 stack.push_back(tmp);
1936 else
1937 return false;
1938 } break;
1939
1940 // OPCODE: DW_OP_bregN
1941 // OPERANDS:
1942 // SLEB128 offset from register N
1943 // DESCRIPTION: Value is in memory at the address specified by register
1944 // N plus an offset.
1945 case DW_OP_breg0:
1946 case DW_OP_breg1:
1947 case DW_OP_breg2:
1948 case DW_OP_breg3:
1949 case DW_OP_breg4:
1950 case DW_OP_breg5:
1951 case DW_OP_breg6:
1952 case DW_OP_breg7:
1953 case DW_OP_breg8:
1954 case DW_OP_breg9:
1955 case DW_OP_breg10:
1956 case DW_OP_breg11:
1957 case DW_OP_breg12:
1958 case DW_OP_breg13:
1959 case DW_OP_breg14:
1960 case DW_OP_breg15:
1961 case DW_OP_breg16:
1962 case DW_OP_breg17:
1963 case DW_OP_breg18:
1964 case DW_OP_breg19:
1965 case DW_OP_breg20:
1966 case DW_OP_breg21:
1967 case DW_OP_breg22:
1968 case DW_OP_breg23:
1969 case DW_OP_breg24:
1970 case DW_OP_breg25:
1971 case DW_OP_breg26:
1972 case DW_OP_breg27:
1973 case DW_OP_breg28:
1974 case DW_OP_breg29:
1975 case DW_OP_breg30:
1976 case DW_OP_breg31: {
1977 reg_num = op - DW_OP_breg0;
1978
1979 if (ReadRegisterValueAsScalar(reg_ctx, reg_kind, reg_num, error_ptr,
1980 tmp)) {
1981 int64_t breg_offset = opcodes.GetSLEB128(&offset);
1982 tmp.ResolveValue(exe_ctx) += (uint64_t)breg_offset;
1983 tmp.ClearContext();
1984 stack.push_back(tmp);
1985 stack.back().SetValueType(Value::ValueType::LoadAddress);
1986 } else
1987 return false;
1988 } break;
1989 // OPCODE: DW_OP_bregx
1990 // OPERANDS: 2
1991 // ULEB128 literal operand that encodes the register.
1992 // SLEB128 offset from register N
1993 // DESCRIPTION: Value is in memory at the address specified by register
1994 // N plus an offset.
1995 case DW_OP_bregx: {
1996 reg_num = opcodes.GetULEB128(&offset);
1997
1998 if (ReadRegisterValueAsScalar(reg_ctx, reg_kind, reg_num, error_ptr,
1999 tmp)) {
2000 int64_t breg_offset = opcodes.GetSLEB128(&offset);
2001 tmp.ResolveValue(exe_ctx) += (uint64_t)breg_offset;
2002 tmp.ClearContext();
2003 stack.push_back(tmp);
2004 stack.back().SetValueType(Value::ValueType::LoadAddress);
2005 } else
2006 return false;
2007 } break;
2008
2009 case DW_OP_fbreg:
2010 if (exe_ctx) {
2011 if (frame) {
2012 Scalar value;
2013 if (frame->GetFrameBaseValue(value, error_ptr)) {
2014 int64_t fbreg_offset = opcodes.GetSLEB128(&offset);
2015 value += fbreg_offset;
2016 stack.push_back(value);
2017 stack.back().SetValueType(Value::ValueType::LoadAddress);
2018 } else
2019 return false;
2020 } else {
2021 if (error_ptr)
2022 error_ptr->SetErrorString(
2023 "Invalid stack frame in context for DW_OP_fbreg opcode.");
2024 return false;
2025 }
2026 } else {
2027 if (error_ptr)
2028 error_ptr->SetErrorString(
2029 "NULL execution context for DW_OP_fbreg.\n");
2030 return false;
2031 }
2032
2033 break;
2034
2035 // OPCODE: DW_OP_nop
2036 // OPERANDS: none
2037 // DESCRIPTION: A place holder. It has no effect on the location stack
2038 // or any of its values.
2039 case DW_OP_nop:
2040 break;
2041
2042 // OPCODE: DW_OP_piece
2043 // OPERANDS: 1
2044 // ULEB128: byte size of the piece
2045 // DESCRIPTION: The operand describes the size in bytes of the piece of
2046 // the object referenced by the DWARF expression whose result is at the top
2047 // of the stack. If the piece is located in a register, but does not occupy
2048 // the entire register, the placement of the piece within that register is
2049 // defined by the ABI.
2050 //
2051 // Many compilers store a single variable in sets of registers, or store a
2052 // variable partially in memory and partially in registers. DW_OP_piece
2053 // provides a way of describing how large a part of a variable a particular
2054 // DWARF expression refers to.
2055 case DW_OP_piece: {
2056 LocationDescriptionKind piece_locdesc = dwarf4_location_description_kind;
2057 // Reset for the next piece.
2058 dwarf4_location_description_kind = Memory;
2059
2060 const uint64_t piece_byte_size = opcodes.GetULEB128(&offset);
2061
2062 if (piece_byte_size > 0) {
2063 Value curr_piece;
2064
2065 if (stack.empty()) {
2066 UpdateValueTypeFromLocationDescription(
2067 log, dwarf_cu, LocationDescriptionKind::Empty);
2068 // In a multi-piece expression, this means that the current piece is
2069 // not available. Fill with zeros for now by resizing the data and
2070 // appending it
2071 curr_piece.ResizeData(piece_byte_size);
2072 // Note that "0" is not a correct value for the unknown bits.
2073 // It would be better to also return a mask of valid bits together
2074 // with the expression result, so the debugger can print missing
2075 // members as "<optimized out>" or something.
2076 ::memset(curr_piece.GetBuffer().GetBytes(), 0, piece_byte_size);
2077 pieces.AppendDataToHostBuffer(curr_piece);
2078 } else {
2079 Status error;
2080 // Extract the current piece into "curr_piece"
2081 Value curr_piece_source_value(stack.back());
2082 stack.pop_back();
2083 UpdateValueTypeFromLocationDescription(log, dwarf_cu, piece_locdesc,
2084 &curr_piece_source_value);
2085
2086 const Value::ValueType curr_piece_source_value_type =
2087 curr_piece_source_value.GetValueType();
2088 switch (curr_piece_source_value_type) {
2089 case Value::ValueType::Invalid:
2090 return false;
2091 case Value::ValueType::LoadAddress:
2092 if (process) {
2093 if (curr_piece.ResizeData(piece_byte_size) == piece_byte_size) {
2094 lldb::addr_t load_addr =
2095 curr_piece_source_value.GetScalar().ULongLong(
2096 LLDB_INVALID_ADDRESS(18446744073709551615UL));
2097 if (process->ReadMemory(
2098 load_addr, curr_piece.GetBuffer().GetBytes(),
2099 piece_byte_size, error) != piece_byte_size) {
2100 if (error_ptr)
2101 error_ptr->SetErrorStringWithFormat(
2102 "failed to read memory DW_OP_piece(%" PRIu64"l" "u"
2103 ") from 0x%" PRIx64"l" "x",
2104 piece_byte_size, load_addr);
2105 return false;
2106 }
2107 } else {
2108 if (error_ptr)
2109 error_ptr->SetErrorStringWithFormat(
2110 "failed to resize the piece memory buffer for "
2111 "DW_OP_piece(%" PRIu64"l" "u" ")",
2112 piece_byte_size);
2113 return false;
2114 }
2115 }
2116 break;
2117
2118 case Value::ValueType::FileAddress:
2119 case Value::ValueType::HostAddress:
2120 if (error_ptr) {
2121 lldb::addr_t addr = curr_piece_source_value.GetScalar().ULongLong(
2122 LLDB_INVALID_ADDRESS(18446744073709551615UL));
2123 error_ptr->SetErrorStringWithFormat(
2124 "failed to read memory DW_OP_piece(%" PRIu64"l" "u"
2125 ") from %s address 0x%" PRIx64"l" "x",
2126 piece_byte_size, curr_piece_source_value.GetValueType() ==
2127 Value::ValueType::FileAddress
2128 ? "file"
2129 : "host",
2130 addr);
2131 }
2132 return false;
2133
2134 case Value::ValueType::Scalar: {
2135 uint32_t bit_size = piece_byte_size * 8;
2136 uint32_t bit_offset = 0;
2137 Scalar &scalar = curr_piece_source_value.GetScalar();
2138 if (!scalar.ExtractBitfield(
2139 bit_size, bit_offset)) {
2140 if (error_ptr)
2141 error_ptr->SetErrorStringWithFormat(
2142 "unable to extract %" PRIu64"l" "u" " bytes from a %" PRIu64"l" "u"
2143 " byte scalar value.",
2144 piece_byte_size,
2145 (uint64_t)curr_piece_source_value.GetScalar()
2146 .GetByteSize());
2147 return false;
2148 }
2149 // Create curr_piece with bit_size. By default Scalar
2150 // grows to the nearest host integer type.
2151 llvm::APInt fail_value(1, 0, false);
2152 llvm::APInt ap_int = scalar.UInt128(fail_value);
2153 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", 2153, __extension__
__PRETTY_FUNCTION__))
;
2154 llvm::ArrayRef<uint64_t> buf{ap_int.getRawData(),
2155 ap_int.getNumWords()};
2156 curr_piece.GetScalar() = Scalar(llvm::APInt(bit_size, buf));
2157 } break;
2158 }
2159
2160 // Check if this is the first piece?
2161 if (op_piece_offset == 0) {
2162 // This is the first piece, we should push it back onto the stack
2163 // so subsequent pieces will be able to access this piece and add
2164 // to it.
2165 if (pieces.AppendDataToHostBuffer(curr_piece) == 0) {
2166 if (error_ptr)
2167 error_ptr->SetErrorString("failed to append piece data");
2168 return false;
2169 }
2170 } else {
2171 // If this is the second or later piece there should be a value on
2172 // the stack.
2173 if (pieces.GetBuffer().GetByteSize() != op_piece_offset) {
2174 if (error_ptr)
2175 error_ptr->SetErrorStringWithFormat(
2176 "DW_OP_piece for offset %" PRIu64"l" "u"
2177 " but top of stack is of size %" PRIu64"l" "u",
2178 op_piece_offset, pieces.GetBuffer().GetByteSize());
2179 return false;
2180 }
2181
2182 if (pieces.AppendDataToHostBuffer(curr_piece) == 0) {
2183 if (error_ptr)
2184 error_ptr->SetErrorString("failed to append piece data");
2185 return false;
2186 }
2187 }
2188 }
2189 op_piece_offset += piece_byte_size;
2190 }
2191 } break;
2192
2193 case DW_OP_bit_piece: // 0x9d ULEB128 bit size, ULEB128 bit offset (DWARF3);
2194 if (stack.size() < 1) {
2195 UpdateValueTypeFromLocationDescription(log, dwarf_cu,
2196 LocationDescriptionKind::Empty);
2197 // Reset for the next piece.
2198 dwarf4_location_description_kind = Memory;
2199 if (error_ptr)
2200 error_ptr->SetErrorString(
2201 "Expression stack needs at least 1 item for DW_OP_bit_piece.");
2202 return false;
2203 } else {
2204 UpdateValueTypeFromLocationDescription(
2205 log, dwarf_cu, dwarf4_location_description_kind, &stack.back());
2206 // Reset for the next piece.
2207 dwarf4_location_description_kind = Memory;
2208 const uint64_t piece_bit_size = opcodes.GetULEB128(&offset);
2209 const uint64_t piece_bit_offset = opcodes.GetULEB128(&offset);
2210 switch (stack.back().GetValueType()) {
2211 case Value::ValueType::Invalid:
2212 return false;
2213 case Value::ValueType::Scalar: {
2214 if (!stack.back().GetScalar().ExtractBitfield(piece_bit_size,
2215 piece_bit_offset)) {
2216 if (error_ptr)
2217 error_ptr->SetErrorStringWithFormat(
2218 "unable to extract %" PRIu64"l" "u" " bit value with %" PRIu64"l" "u"
2219 " bit offset from a %" PRIu64"l" "u" " bit scalar value.",
2220 piece_bit_size, piece_bit_offset,
2221 (uint64_t)(stack.back().GetScalar().GetByteSize() * 8));
2222 return false;
2223 }
2224 } break;
2225
2226 case Value::ValueType::FileAddress:
2227 case Value::ValueType::LoadAddress:
2228 case Value::ValueType::HostAddress:
2229 if (error_ptr) {
2230 error_ptr->SetErrorStringWithFormat(
2231 "unable to extract DW_OP_bit_piece(bit_size = %" PRIu64"l" "u"
2232 ", bit_offset = %" PRIu64"l" "u" ") from an address value.",
2233 piece_bit_size, piece_bit_offset);
2234 }
2235 return false;
2236 }
2237 }
2238 break;
2239
2240 // OPCODE: DW_OP_implicit_value
2241 // OPERANDS: 2
2242 // ULEB128 size of the value block in bytes
2243 // uint8_t* block bytes encoding value in target's memory
2244 // representation
2245 // DESCRIPTION: Value is immediately stored in block in the debug info with
2246 // the memory representation of the target.
2247 case DW_OP_implicit_value: {
2248 dwarf4_location_description_kind = Implicit;
2249
2250 const uint32_t len = opcodes.GetULEB128(&offset);
2251 const void *data = opcodes.GetData(&offset, len);
2252
2253 if (!data) {
2254 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)
;
2255 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);
2256 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);
;
2257 return false;
2258 }
2259
2260 Value result(data, len);
2261 stack.push_back(result);
2262 break;
2263 }
2264
2265 case DW_OP_implicit_pointer: {
2266 dwarf4_location_description_kind = Implicit;
Value stored to 'dwarf4_location_description_kind' is never read
2267 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);
;
2268 return false;
2269 }
2270
2271 // OPCODE: DW_OP_push_object_address
2272 // OPERANDS: none
2273 // DESCRIPTION: Pushes the address of the object currently being
2274 // evaluated as part of evaluation of a user presented expression. This
2275 // object may correspond to an independent variable described by its own
2276 // DIE or it may be a component of an array, structure, or class whose
2277 // address has been dynamically determined by an earlier step during user
2278 // expression evaluation.
2279 case DW_OP_push_object_address:
2280 if (object_address_ptr)
2281 stack.push_back(*object_address_ptr);
2282 else {
2283 if (error_ptr)
2284 error_ptr->SetErrorString("DW_OP_push_object_address used without "
2285 "specifying an object address");
2286 return false;
2287 }
2288 break;
2289
2290 // OPCODE: DW_OP_call2
2291 // OPERANDS:
2292 // uint16_t compile unit relative offset of a DIE
2293 // DESCRIPTION: Performs subroutine calls during evaluation
2294 // of a DWARF expression. The operand is the 2-byte unsigned offset of a
2295 // debugging information entry in the current compilation unit.
2296 //
2297 // Operand interpretation is exactly like that for DW_FORM_ref2.
2298 //
2299 // This operation transfers control of DWARF expression evaluation to the
2300 // DW_AT_location attribute of the referenced DIE. If there is no such
2301 // attribute, then there is no effect. Execution of the DWARF expression of
2302 // a DW_AT_location attribute may add to and/or remove from values on the
2303 // stack. Execution returns to the point following the call when the end of
2304 // the attribute is reached. Values on the stack at the time of the call
2305 // may be used as parameters by the called expression and values left on
2306 // the stack by the called expression may be used as return values by prior
2307 // agreement between the calling and called expressions.
2308 case DW_OP_call2:
2309 if (error_ptr)
2310 error_ptr->SetErrorString("Unimplemented opcode DW_OP_call2.");
2311 return false;
2312 // OPCODE: DW_OP_call4
2313 // OPERANDS: 1
2314 // uint32_t compile unit relative offset of a DIE
2315 // DESCRIPTION: Performs a subroutine call during evaluation of a DWARF
2316 // expression. For DW_OP_call4, the operand is a 4-byte unsigned offset of
2317 // a debugging information entry in the current compilation unit.
2318 //
2319 // Operand interpretation DW_OP_call4 is exactly like that for
2320 // DW_FORM_ref4.
2321 //
2322 // This operation transfers control of DWARF expression evaluation to the
2323 // DW_AT_location attribute of the referenced DIE. If there is no such
2324 // attribute, then there is no effect. Execution of the DWARF expression of
2325 // a DW_AT_location attribute may add to and/or remove from values on the
2326 // stack. Execution returns to the point following the call when the end of
2327 // the attribute is reached. Values on the stack at the time of the call
2328 // may be used as parameters by the called expression and values left on
2329 // the stack by the called expression may be used as return values by prior
2330 // agreement between the calling and called expressions.
2331 case DW_OP_call4:
2332 if (error_ptr)
2333 error_ptr->SetErrorString("Unimplemented opcode DW_OP_call4.");
2334 return false;
2335
2336 // OPCODE: DW_OP_stack_value
2337 // OPERANDS: None
2338 // DESCRIPTION: Specifies that the object does not exist in memory but
2339 // rather is a constant value. The value from the top of the stack is the
2340 // value to be used. This is the actual object value and not the location.
2341 case DW_OP_stack_value:
2342 dwarf4_location_description_kind = Implicit;
2343 if (stack.empty()) {
2344 if (error_ptr)
2345 error_ptr->SetErrorString(
2346 "Expression stack needs at least 1 item for DW_OP_stack_value.");
2347 return false;
2348 }
2349 stack.back().SetValueType(Value::ValueType::Scalar);
2350 break;
2351
2352 // OPCODE: DW_OP_convert
2353 // OPERANDS: 1
2354 // A ULEB128 that is either a DIE offset of a
2355 // DW_TAG_base_type or 0 for the generic (pointer-sized) type.
2356 //
2357 // DESCRIPTION: Pop the top stack element, convert it to a
2358 // different type, and push the result.
2359 case DW_OP_convert: {
2360 if (stack.size() < 1) {
2361 if (error_ptr)
2362 error_ptr->SetErrorString(
2363 "Expression stack needs at least 1 item for DW_OP_convert.");
2364 return false;
2365 }
2366 const uint64_t die_offset = opcodes.GetULEB128(&offset);
2367 uint64_t bit_size;
2368 bool sign;
2369 if (die_offset == 0) {
2370 // The generic type has the size of an address on the target
2371 // machine and an unspecified signedness. Scalar has no
2372 // "unspecified signedness", so we use unsigned types.
2373 if (!module_sp) {
2374 if (error_ptr)
2375 error_ptr->SetErrorString("No module");
2376 return false;
2377 }
2378 sign = false;
2379 bit_size = module_sp->GetArchitecture().GetAddressByteSize() * 8;
2380 if (!bit_size) {
2381 if (error_ptr)
2382 error_ptr->SetErrorString("unspecified architecture");
2383 return false;
2384 }
2385 } else {
2386 // Retrieve the type DIE that the value is being converted to. This
2387 // offset is compile unit relative so we need to fix it up.
2388 const uint64_t abs_die_offset = die_offset + dwarf_cu->GetOffset();
2389 // FIXME: the constness has annoying ripple effects.
2390 DWARFDIE die = const_cast<DWARFUnit *>(dwarf_cu)->GetDIE(abs_die_offset);
2391 if (!die) {
2392 if (error_ptr)
2393 error_ptr->SetErrorString("Cannot resolve DW_OP_convert type DIE");
2394 return false;
2395 }
2396 uint64_t encoding =
2397 die.GetAttributeValueAsUnsigned(DW_AT_encoding, DW_ATE_hi_user);
2398 bit_size = die.GetAttributeValueAsUnsigned(DW_AT_byte_size, 0) * 8;
2399 if (!bit_size)
2400 bit_size = die.GetAttributeValueAsUnsigned(DW_AT_bit_size, 0);
2401 if (!bit_size) {
2402 if (error_ptr)
2403 error_ptr->SetErrorString("Unsupported type size in DW_OP_convert");
2404 return false;
2405 }
2406 switch (encoding) {
2407 case DW_ATE_signed:
2408 case DW_ATE_signed_char:
2409 sign = true;
2410 break;
2411 case DW_ATE_unsigned:
2412 case DW_ATE_unsigned_char:
2413 sign = false;
2414 break;
2415 default:
2416 if (error_ptr)
2417 error_ptr->SetErrorString("Unsupported encoding in DW_OP_convert");
2418 return false;
2419 }
2420 }
2421 Scalar &top = stack.back().ResolveValue(exe_ctx);
2422 top.TruncOrExtendTo(bit_size, sign);
2423 break;
2424 }
2425
2426 // OPCODE: DW_OP_call_frame_cfa
2427 // OPERANDS: None
2428 // DESCRIPTION: Specifies a DWARF expression that pushes the value of
2429 // the canonical frame address consistent with the call frame information
2430 // located in .debug_frame (or in the FDEs of the eh_frame section).
2431 case DW_OP_call_frame_cfa:
2432 if (frame) {
2433 // Note that we don't have to parse FDEs because this DWARF expression
2434 // is commonly evaluated with a valid stack frame.
2435 StackID id = frame->GetStackID();
2436 addr_t cfa = id.GetCallFrameAddress();
2437 if (cfa != LLDB_INVALID_ADDRESS(18446744073709551615UL)) {
2438 stack.push_back(Scalar(cfa));
2439 stack.back().SetValueType(Value::ValueType::LoadAddress);
2440 } else if (error_ptr)
2441 error_ptr->SetErrorString("Stack frame does not include a canonical "
2442 "frame address for DW_OP_call_frame_cfa "
2443 "opcode.");
2444 } else {
2445 if (error_ptr)
2446 error_ptr->SetErrorString("Invalid stack frame in context for "
2447 "DW_OP_call_frame_cfa opcode.");
2448 return false;
2449 }
2450 break;
2451
2452 // OPCODE: DW_OP_form_tls_address (or the old pre-DWARFv3 vendor extension
2453 // opcode, DW_OP_GNU_push_tls_address)
2454 // OPERANDS: none
2455 // DESCRIPTION: Pops a TLS offset from the stack, converts it to
2456 // an address in the current thread's thread-local storage block, and
2457 // pushes it on the stack.
2458 case DW_OP_form_tls_address:
2459 case DW_OP_GNU_push_tls_address: {
2460 if (stack.size() < 1) {
2461 if (error_ptr) {
2462 if (op == DW_OP_form_tls_address)
2463 error_ptr->SetErrorString(
2464 "DW_OP_form_tls_address needs an argument.");
2465 else
2466 error_ptr->SetErrorString(
2467 "DW_OP_GNU_push_tls_address needs an argument.");
2468 }
2469 return false;
2470 }
2471
2472 if (!exe_ctx || !module_sp) {
2473 if (error_ptr)
2474 error_ptr->SetErrorString("No context to evaluate TLS within.");
2475 return false;
2476 }
2477
2478 Thread *thread = exe_ctx->GetThreadPtr();
2479 if (!thread) {
2480 if (error_ptr)
2481 error_ptr->SetErrorString("No thread to evaluate TLS within.");
2482 return false;
2483 }
2484
2485 // Lookup the TLS block address for this thread and module.
2486 const addr_t tls_file_addr =
2487 stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS(18446744073709551615UL));
2488 const addr_t tls_load_addr =
2489 thread->GetThreadLocalData(module_sp, tls_file_addr);
2490
2491 if (tls_load_addr == LLDB_INVALID_ADDRESS(18446744073709551615UL)) {
2492 if (error_ptr)
2493 error_ptr->SetErrorString(
2494 "No TLS data currently exists for this thread.");
2495 return false;
2496 }
2497
2498 stack.back().GetScalar() = tls_load_addr;
2499 stack.back().SetValueType(Value::ValueType::LoadAddress);
2500 } break;
2501
2502 // OPCODE: DW_OP_addrx (DW_OP_GNU_addr_index is the legacy name.)
2503 // OPERANDS: 1
2504 // ULEB128: index to the .debug_addr section
2505 // DESCRIPTION: Pushes an address to the stack from the .debug_addr
2506 // section with the base address specified by the DW_AT_addr_base attribute
2507 // and the 0 based index is the ULEB128 encoded index.
2508 case DW_OP_addrx:
2509 case DW_OP_GNU_addr_index: {
2510 if (!dwarf_cu) {
2511 if (error_ptr)
2512 error_ptr->SetErrorString("DW_OP_GNU_addr_index found without a "
2513 "compile unit being specified");
2514 return false;
2515 }
2516 uint64_t index = opcodes.GetULEB128(&offset);
2517 lldb::addr_t value = dwarf_cu->ReadAddressFromDebugAddrSection(index);
2518 stack.push_back(Scalar(value));
2519 if (target &&
2520 target->GetArchitecture().GetCore() == ArchSpec::eCore_wasm32) {
2521 // wasm file sections aren't mapped into memory, therefore addresses can
2522 // never point into a file section and are always LoadAddresses.
2523 stack.back().SetValueType(Value::ValueType::LoadAddress);
2524 } else {
2525 stack.back().SetValueType(Value::ValueType::FileAddress);
2526 }
2527 } break;
2528
2529 // OPCODE: DW_OP_GNU_const_index
2530 // OPERANDS: 1
2531 // ULEB128: index to the .debug_addr section
2532 // DESCRIPTION: Pushes an constant with the size of a machine address to
2533 // the stack from the .debug_addr section with the base address specified
2534 // by the DW_AT_addr_base attribute and the 0 based index is the ULEB128
2535 // encoded index.
2536 case DW_OP_GNU_const_index: {
2537 if (!dwarf_cu) {
2538 if (error_ptr)
2539 error_ptr->SetErrorString("DW_OP_GNU_const_index found without a "
2540 "compile unit being specified");
2541 return false;
2542 }
2543 uint64_t index = opcodes.GetULEB128(&offset);
2544 lldb::addr_t value = dwarf_cu->ReadAddressFromDebugAddrSection(index);
2545 stack.push_back(Scalar(value));
2546 } break;
2547
2548 case DW_OP_GNU_entry_value:
2549 case DW_OP_entry_value: {
2550 if (!Evaluate_DW_OP_entry_value(stack, exe_ctx, reg_ctx, opcodes, offset,
2551 error_ptr, log)) {
2552 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);
2553 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);
;
2554 return false;
2555 }
2556 break;
2557 }
2558
2559 default:
2560 if (error_ptr)
2561 error_ptr->SetErrorStringWithFormatv(
2562 "Unhandled opcode {0} in DWARFExpression", LocationAtom(op));
2563 return false;
2564 }
2565 }
2566
2567 if (stack.empty()) {
2568 // Nothing on the stack, check if we created a piece value from DW_OP_piece
2569 // or DW_OP_bit_piece opcodes
2570 if (pieces.GetBuffer().GetByteSize()) {
2571 result = pieces;
2572 return true;
2573 }
2574 if (error_ptr)
2575 error_ptr->SetErrorString("Stack empty after evaluation.");
2576 return false;
2577 }
2578
2579 UpdateValueTypeFromLocationDescription(
2580 log, dwarf_cu, dwarf4_location_description_kind, &stack.back());
2581
2582 if (log && log->GetVerbose()) {
2583 size_t count = stack.size();
2584 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)
2585 "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)
;
2586 for (size_t i = 0; i < count; ++i) {
2587 StreamString new_value;
2588 new_value.Printf("[%" PRIu64"l" "u" "]", (uint64_t)i);
2589 stack[i].Dump(&new_value);
2590 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)
;
2591 }
2592 }
2593 result = stack.back();
2594 return true; // Return true on success
2595}
2596
2597bool DWARFExpression::ParseDWARFLocationList(
2598 const DWARFUnit *dwarf_cu, const DataExtractor &data,
2599 DWARFExpressionList *location_list) {
2600 location_list->Clear();
2601 std::unique_ptr<llvm::DWARFLocationTable> loctable_up =
2602 dwarf_cu->GetLocationTable(data);
2603 Log *log = GetLog(LLDBLog::Expressions);
2604 auto lookup_addr =
2605 [&](uint32_t index) -> llvm::Optional<llvm::object::SectionedAddress> {
2606 addr_t address = dwarf_cu->ReadAddressFromDebugAddrSection(index);
2607 if (address == LLDB_INVALID_ADDRESS(18446744073709551615UL))
2608 return llvm::None;
2609 return llvm::object::SectionedAddress{address};
2610 };
2611 auto process_list = [&](llvm::Expected<llvm::DWARFLocationExpression> loc) {
2612 if (!loc) {
2613 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)
;
2614 return true;
2615 }
2616 auto buffer_sp =
2617 std::make_shared<DataBufferHeap>(loc->Expr.data(), loc->Expr.size());
2618 DWARFExpression expr = DWARFExpression(DataExtractor(
2619 buffer_sp, data.GetByteOrder(), data.GetAddressByteSize()));
2620 location_list->AddExpression(loc->Range->LowPC, loc->Range->HighPC, expr);
2621 return true;
2622 };
2623 llvm::Error error = loctable_up->visitAbsoluteLocationList(
2624 0, llvm::object::SectionedAddress{dwarf_cu->GetBaseAddress()},
2625 lookup_addr, process_list);
2626 location_list->Sort();
2627 if (error) {
2628 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)
;
2629 return false;
2630 }
2631 return true;
2632}
2633
2634bool DWARFExpression::MatchesOperand(
2635 StackFrame &frame, const Instruction::Operand &operand) const {
2636 using namespace OperandMatchers;
2637
2638 RegisterContextSP reg_ctx_sp = frame.GetRegisterContext();
2639 if (!reg_ctx_sp) {
2640 return false;
2641 }
2642
2643 DataExtractor opcodes(m_data);
2644
2645 lldb::offset_t op_offset = 0;
2646 uint8_t opcode = opcodes.GetU8(&op_offset);
2647
2648 if (opcode == DW_OP_fbreg) {
2649 int64_t offset = opcodes.GetSLEB128(&op_offset);
2650
2651 DWARFExpressionList *fb_expr = frame.GetFrameBaseExpression(nullptr);
2652 if (!fb_expr) {
2653 return false;
2654 }
2655
2656 auto recurse = [&frame, fb_expr](const Instruction::Operand &child) {
2657 return fb_expr->MatchesOperand(frame, child);
2658 };
2659
2660 if (!offset &&
2661 MatchUnaryOp(MatchOpType(Instruction::Operand::Type::Dereference),
2662 recurse)(operand)) {
2663 return true;
2664 }
2665
2666 return MatchUnaryOp(
2667 MatchOpType(Instruction::Operand::Type::Dereference),
2668 MatchBinaryOp(MatchOpType(Instruction::Operand::Type::Sum),
2669 MatchImmOp(offset), recurse))(operand);
2670 }
2671
2672 bool dereference = false;
2673 const RegisterInfo *reg = nullptr;
2674 int64_t offset = 0;
2675
2676 if (opcode >= DW_OP_reg0 && opcode <= DW_OP_reg31) {
2677 reg = reg_ctx_sp->GetRegisterInfo(m_reg_kind, opcode - DW_OP_reg0);
2678 } else if (opcode >= DW_OP_breg0 && opcode <= DW_OP_breg31) {
2679 offset = opcodes.GetSLEB128(&op_offset);
2680 reg = reg_ctx_sp->GetRegisterInfo(m_reg_kind, opcode - DW_OP_breg0);
2681 } else if (opcode == DW_OP_regx) {
2682 uint32_t reg_num = static_cast<uint32_t>(opcodes.GetULEB128(&op_offset));
2683 reg = reg_ctx_sp->GetRegisterInfo(m_reg_kind, reg_num);
2684 } else if (opcode == DW_OP_bregx) {
2685 uint32_t reg_num = static_cast<uint32_t>(opcodes.GetULEB128(&op_offset));
2686 offset = opcodes.GetSLEB128(&op_offset);
2687 reg = reg_ctx_sp->GetRegisterInfo(m_reg_kind, reg_num);
2688 } else {
2689 return false;
2690 }
2691
2692 if (!reg) {
2693 return false;
2694 }
2695
2696 if (dereference) {
2697 if (!offset &&
2698 MatchUnaryOp(MatchOpType(Instruction::Operand::Type::Dereference),
2699 MatchRegOp(*reg))(operand)) {
2700 return true;
2701 }
2702
2703 return MatchUnaryOp(
2704 MatchOpType(Instruction::Operand::Type::Dereference),
2705 MatchBinaryOp(MatchOpType(Instruction::Operand::Type::Sum),
2706 MatchRegOp(*reg),
2707 MatchImmOp(offset)))(operand);
2708 } else {
2709 return MatchRegOp(*reg)(operand);
2710 }
2711}