1 | //===-- DWARFExpression.cpp -----------------------------------------------===// |
---|---|
2 | // |
3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
4 | // See https://llvm.org/LICENSE.txt for license information. |
5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
6 | // |
7 | //===----------------------------------------------------------------------===// |
8 | |
9 | #include "lldb/Expression/DWARFExpression.h" |
10 | |
11 | #include <cinttypes> |
12 | |
13 | #include <optional> |
14 | #include <vector> |
15 | |
16 | #include "lldb/Core/Module.h" |
17 | #include "lldb/Core/Value.h" |
18 | #include "lldb/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/DWARFExpression.h" |
40 | |
41 | using namespace lldb; |
42 | using namespace lldb_private; |
43 | using namespace lldb_private::dwarf; |
44 | using namespace lldb_private::plugin::dwarf; |
45 | |
46 | // DWARFExpression constructor |
47 | DWARFExpression::DWARFExpression() : m_data() {} |
48 | |
49 | DWARFExpression::DWARFExpression(const DataExtractor &data) : m_data(data) {} |
50 | |
51 | // Destructor |
52 | DWARFExpression::~DWARFExpression() = default; |
53 | |
54 | bool DWARFExpression::IsValid() const { return m_data.GetByteSize() > 0; } |
55 | |
56 | void DWARFExpression::UpdateValue(uint64_t const_value, |
57 | lldb::offset_t const_value_byte_size, |
58 | uint8_t addr_byte_size) { |
59 | if (!const_value_byte_size) |
60 | return; |
61 | |
62 | m_data.SetData( |
63 | data_sp: DataBufferSP(new DataBufferHeap(&const_value, const_value_byte_size))); |
64 | m_data.SetByteOrder(endian::InlHostByteOrder()); |
65 | m_data.SetAddressByteSize(addr_byte_size); |
66 | } |
67 | |
68 | void DWARFExpression::DumpLocation(Stream *s, lldb::DescriptionLevel level, |
69 | ABI *abi) const { |
70 | auto *MCRegInfo = abi ? &abi->GetMCRegisterInfo() : nullptr; |
71 | auto GetRegName = [&MCRegInfo](uint64_t DwarfRegNum, |
72 | bool IsEH) -> llvm::StringRef { |
73 | if (!MCRegInfo) |
74 | return {}; |
75 | if (std::optional<unsigned> LLVMRegNum = |
76 | MCRegInfo->getLLVMRegNum(RegNum: DwarfRegNum, isEH: IsEH)) |
77 | if (const char *RegName = MCRegInfo->getName(RegNo: *LLVMRegNum)) |
78 | return llvm::StringRef(RegName); |
79 | return {}; |
80 | }; |
81 | llvm::DIDumpOptions DumpOpts; |
82 | DumpOpts.GetNameForDWARFReg = GetRegName; |
83 | llvm::DWARFExpression E(m_data.GetAsLLVM(), m_data.GetAddressByteSize()); |
84 | llvm::DWARFExpressionPrinter::print(E: &E, OS&: s->AsRawOstream(), DumpOpts, U: nullptr); |
85 | } |
86 | |
87 | RegisterKind DWARFExpression::GetRegisterKind() const { return m_reg_kind; } |
88 | |
89 | void DWARFExpression::SetRegisterKind(RegisterKind reg_kind) { |
90 | m_reg_kind = reg_kind; |
91 | } |
92 | |
93 | static llvm::Error ReadRegisterValueAsScalar(RegisterContext *reg_ctx, |
94 | lldb::RegisterKind reg_kind, |
95 | uint32_t reg_num, Value &value) { |
96 | if (reg_ctx == nullptr) |
97 | return llvm::createStringError(Fmt: "no register context in frame"); |
98 | |
99 | const uint32_t native_reg = |
100 | reg_ctx->ConvertRegisterKindToRegisterNumber(kind: reg_kind, num: reg_num); |
101 | if (native_reg == LLDB_INVALID_REGNUM) |
102 | return llvm::createStringError( |
103 | Fmt: "unable to convert register kind=%u reg_num=%u to a native " |
104 | "register number", |
105 | Vals: reg_kind, Vals: reg_num); |
106 | |
107 | const RegisterInfo *reg_info = reg_ctx->GetRegisterInfoAtIndex(reg: native_reg); |
108 | RegisterValue reg_value; |
109 | if (reg_ctx->ReadRegister(reg_info, reg_value)) { |
110 | if (reg_value.GetScalarValue(scalar&: value.GetScalar())) { |
111 | value.SetValueType(Value::ValueType::Scalar); |
112 | value.SetContext(context_type: Value::ContextType::RegisterInfo, |
113 | p: const_cast<RegisterInfo *>(reg_info)); |
114 | return llvm::Error::success(); |
115 | } |
116 | |
117 | // If we get this error, then we need to implement a value buffer in |
118 | // the dwarf expression evaluation function... |
119 | return llvm::createStringError( |
120 | Fmt: "register %s can't be converted to a scalar value", Vals: reg_info->name); |
121 | } |
122 | |
123 | return llvm::createStringError(Fmt: "register %s is not available", |
124 | Vals: reg_info->name); |
125 | } |
126 | |
127 | /// Return the length in bytes of the set of operands for \p op. No guarantees |
128 | /// are made on the state of \p data after this call. |
129 | static lldb::offset_t |
130 | GetOpcodeDataSize(const DataExtractor &data, const lldb::offset_t data_offset, |
131 | const LocationAtom op, |
132 | const DWARFExpression::Delegate *dwarf_cu) { |
133 | lldb::offset_t offset = data_offset; |
134 | switch (op) { |
135 | // Only used in LLVM metadata. |
136 | case DW_OP_LLVM_fragment: |
137 | case DW_OP_LLVM_convert: |
138 | case DW_OP_LLVM_tag_offset: |
139 | case DW_OP_LLVM_entry_value: |
140 | case DW_OP_LLVM_implicit_pointer: |
141 | case DW_OP_LLVM_arg: |
142 | case DW_OP_LLVM_extract_bits_sext: |
143 | case DW_OP_LLVM_extract_bits_zext: |
144 | break; |
145 | // Vendor extensions: |
146 | case DW_OP_HP_is_value: |
147 | case DW_OP_HP_fltconst4: |
148 | case DW_OP_HP_fltconst8: |
149 | case DW_OP_HP_mod_range: |
150 | case DW_OP_HP_unmod_range: |
151 | case DW_OP_HP_tls: |
152 | case DW_OP_INTEL_bit_piece: |
153 | case DW_OP_WASM_location: |
154 | case DW_OP_WASM_location_int: |
155 | case DW_OP_APPLE_uninit: |
156 | case DW_OP_PGI_omp_thread_num: |
157 | case DW_OP_hi_user: |
158 | case DW_OP_GNU_implicit_pointer: |
159 | break; |
160 | |
161 | case DW_OP_addr: |
162 | case DW_OP_call_ref: // 0x9a 1 address sized offset of DIE (DWARF3) |
163 | return data.GetAddressByteSize(); |
164 | |
165 | // Opcodes with no arguments |
166 | case DW_OP_deref: // 0x06 |
167 | case DW_OP_dup: // 0x12 |
168 | case DW_OP_drop: // 0x13 |
169 | case DW_OP_over: // 0x14 |
170 | case DW_OP_swap: // 0x16 |
171 | case DW_OP_rot: // 0x17 |
172 | case DW_OP_xderef: // 0x18 |
173 | case DW_OP_abs: // 0x19 |
174 | case DW_OP_and: // 0x1a |
175 | case DW_OP_div: // 0x1b |
176 | case DW_OP_minus: // 0x1c |
177 | case DW_OP_mod: // 0x1d |
178 | case DW_OP_mul: // 0x1e |
179 | case DW_OP_neg: // 0x1f |
180 | case DW_OP_not: // 0x20 |
181 | case DW_OP_or: // 0x21 |
182 | case DW_OP_plus: // 0x22 |
183 | case DW_OP_shl: // 0x24 |
184 | case DW_OP_shr: // 0x25 |
185 | case DW_OP_shra: // 0x26 |
186 | case DW_OP_xor: // 0x27 |
187 | case DW_OP_eq: // 0x29 |
188 | case DW_OP_ge: // 0x2a |
189 | case DW_OP_gt: // 0x2b |
190 | case DW_OP_le: // 0x2c |
191 | case DW_OP_lt: // 0x2d |
192 | case DW_OP_ne: // 0x2e |
193 | case DW_OP_lit0: // 0x30 |
194 | case DW_OP_lit1: // 0x31 |
195 | case DW_OP_lit2: // 0x32 |
196 | case DW_OP_lit3: // 0x33 |
197 | case DW_OP_lit4: // 0x34 |
198 | case DW_OP_lit5: // 0x35 |
199 | case DW_OP_lit6: // 0x36 |
200 | case DW_OP_lit7: // 0x37 |
201 | case DW_OP_lit8: // 0x38 |
202 | case DW_OP_lit9: // 0x39 |
203 | case DW_OP_lit10: // 0x3A |
204 | case DW_OP_lit11: // 0x3B |
205 | case DW_OP_lit12: // 0x3C |
206 | case DW_OP_lit13: // 0x3D |
207 | case DW_OP_lit14: // 0x3E |
208 | case DW_OP_lit15: // 0x3F |
209 | case DW_OP_lit16: // 0x40 |
210 | case DW_OP_lit17: // 0x41 |
211 | case DW_OP_lit18: // 0x42 |
212 | case DW_OP_lit19: // 0x43 |
213 | case DW_OP_lit20: // 0x44 |
214 | case DW_OP_lit21: // 0x45 |
215 | case DW_OP_lit22: // 0x46 |
216 | case DW_OP_lit23: // 0x47 |
217 | case DW_OP_lit24: // 0x48 |
218 | case DW_OP_lit25: // 0x49 |
219 | case DW_OP_lit26: // 0x4A |
220 | case DW_OP_lit27: // 0x4B |
221 | case DW_OP_lit28: // 0x4C |
222 | case DW_OP_lit29: // 0x4D |
223 | case DW_OP_lit30: // 0x4E |
224 | case DW_OP_lit31: // 0x4f |
225 | case DW_OP_reg0: // 0x50 |
226 | case DW_OP_reg1: // 0x51 |
227 | case DW_OP_reg2: // 0x52 |
228 | case DW_OP_reg3: // 0x53 |
229 | case DW_OP_reg4: // 0x54 |
230 | case DW_OP_reg5: // 0x55 |
231 | case DW_OP_reg6: // 0x56 |
232 | case DW_OP_reg7: // 0x57 |
233 | case DW_OP_reg8: // 0x58 |
234 | case DW_OP_reg9: // 0x59 |
235 | case DW_OP_reg10: // 0x5A |
236 | case DW_OP_reg11: // 0x5B |
237 | case DW_OP_reg12: // 0x5C |
238 | case DW_OP_reg13: // 0x5D |
239 | case DW_OP_reg14: // 0x5E |
240 | case DW_OP_reg15: // 0x5F |
241 | case DW_OP_reg16: // 0x60 |
242 | case DW_OP_reg17: // 0x61 |
243 | case DW_OP_reg18: // 0x62 |
244 | case DW_OP_reg19: // 0x63 |
245 | case DW_OP_reg20: // 0x64 |
246 | case DW_OP_reg21: // 0x65 |
247 | case DW_OP_reg22: // 0x66 |
248 | case DW_OP_reg23: // 0x67 |
249 | case DW_OP_reg24: // 0x68 |
250 | case DW_OP_reg25: // 0x69 |
251 | case DW_OP_reg26: // 0x6A |
252 | case DW_OP_reg27: // 0x6B |
253 | case DW_OP_reg28: // 0x6C |
254 | case DW_OP_reg29: // 0x6D |
255 | case DW_OP_reg30: // 0x6E |
256 | case DW_OP_reg31: // 0x6F |
257 | case DW_OP_nop: // 0x96 |
258 | case DW_OP_push_object_address: // 0x97 DWARF3 |
259 | case DW_OP_form_tls_address: // 0x9b DWARF3 |
260 | case DW_OP_call_frame_cfa: // 0x9c DWARF3 |
261 | case DW_OP_stack_value: // 0x9f DWARF4 |
262 | case DW_OP_GNU_push_tls_address: // 0xe0 GNU extension |
263 | return 0; |
264 | |
265 | // Opcodes with a single 1 byte arguments |
266 | case DW_OP_const1u: // 0x08 1 1-byte constant |
267 | case DW_OP_const1s: // 0x09 1 1-byte constant |
268 | case DW_OP_pick: // 0x15 1 1-byte stack index |
269 | case DW_OP_deref_size: // 0x94 1 1-byte size of data retrieved |
270 | case DW_OP_xderef_size: // 0x95 1 1-byte size of data retrieved |
271 | case DW_OP_deref_type: // 0xa6 1 1-byte constant |
272 | return 1; |
273 | |
274 | // Opcodes with a single 2 byte arguments |
275 | case DW_OP_const2u: // 0x0a 1 2-byte constant |
276 | case DW_OP_const2s: // 0x0b 1 2-byte constant |
277 | case DW_OP_skip: // 0x2f 1 signed 2-byte constant |
278 | case DW_OP_bra: // 0x28 1 signed 2-byte constant |
279 | case DW_OP_call2: // 0x98 1 2-byte offset of DIE (DWARF3) |
280 | return 2; |
281 | |
282 | // Opcodes with a single 4 byte arguments |
283 | case DW_OP_const4u: // 0x0c 1 4-byte constant |
284 | case DW_OP_const4s: // 0x0d 1 4-byte constant |
285 | case DW_OP_call4: // 0x99 1 4-byte offset of DIE (DWARF3) |
286 | return 4; |
287 | |
288 | // Opcodes with a single 8 byte arguments |
289 | case DW_OP_const8u: // 0x0e 1 8-byte constant |
290 | case DW_OP_const8s: // 0x0f 1 8-byte constant |
291 | return 8; |
292 | |
293 | // All opcodes that have a single ULEB (signed or unsigned) argument |
294 | case DW_OP_constu: // 0x10 1 ULEB128 constant |
295 | case DW_OP_consts: // 0x11 1 SLEB128 constant |
296 | case DW_OP_plus_uconst: // 0x23 1 ULEB128 addend |
297 | case DW_OP_breg0: // 0x70 1 ULEB128 register |
298 | case DW_OP_breg1: // 0x71 1 ULEB128 register |
299 | case DW_OP_breg2: // 0x72 1 ULEB128 register |
300 | case DW_OP_breg3: // 0x73 1 ULEB128 register |
301 | case DW_OP_breg4: // 0x74 1 ULEB128 register |
302 | case DW_OP_breg5: // 0x75 1 ULEB128 register |
303 | case DW_OP_breg6: // 0x76 1 ULEB128 register |
304 | case DW_OP_breg7: // 0x77 1 ULEB128 register |
305 | case DW_OP_breg8: // 0x78 1 ULEB128 register |
306 | case DW_OP_breg9: // 0x79 1 ULEB128 register |
307 | case DW_OP_breg10: // 0x7a 1 ULEB128 register |
308 | case DW_OP_breg11: // 0x7b 1 ULEB128 register |
309 | case DW_OP_breg12: // 0x7c 1 ULEB128 register |
310 | case DW_OP_breg13: // 0x7d 1 ULEB128 register |
311 | case DW_OP_breg14: // 0x7e 1 ULEB128 register |
312 | case DW_OP_breg15: // 0x7f 1 ULEB128 register |
313 | case DW_OP_breg16: // 0x80 1 ULEB128 register |
314 | case DW_OP_breg17: // 0x81 1 ULEB128 register |
315 | case DW_OP_breg18: // 0x82 1 ULEB128 register |
316 | case DW_OP_breg19: // 0x83 1 ULEB128 register |
317 | case DW_OP_breg20: // 0x84 1 ULEB128 register |
318 | case DW_OP_breg21: // 0x85 1 ULEB128 register |
319 | case DW_OP_breg22: // 0x86 1 ULEB128 register |
320 | case DW_OP_breg23: // 0x87 1 ULEB128 register |
321 | case DW_OP_breg24: // 0x88 1 ULEB128 register |
322 | case DW_OP_breg25: // 0x89 1 ULEB128 register |
323 | case DW_OP_breg26: // 0x8a 1 ULEB128 register |
324 | case DW_OP_breg27: // 0x8b 1 ULEB128 register |
325 | case DW_OP_breg28: // 0x8c 1 ULEB128 register |
326 | case DW_OP_breg29: // 0x8d 1 ULEB128 register |
327 | case DW_OP_breg30: // 0x8e 1 ULEB128 register |
328 | case DW_OP_breg31: // 0x8f 1 ULEB128 register |
329 | case DW_OP_regx: // 0x90 1 ULEB128 register |
330 | case DW_OP_fbreg: // 0x91 1 SLEB128 offset |
331 | case DW_OP_piece: // 0x93 1 ULEB128 size of piece addressed |
332 | case DW_OP_convert: // 0xa8 1 ULEB128 offset |
333 | case DW_OP_reinterpret: // 0xa9 1 ULEB128 offset |
334 | case DW_OP_addrx: // 0xa1 1 ULEB128 index |
335 | case DW_OP_constx: // 0xa2 1 ULEB128 index |
336 | case DW_OP_xderef_type: // 0xa7 1 ULEB128 index |
337 | case DW_OP_GNU_addr_index: // 0xfb 1 ULEB128 index |
338 | case DW_OP_GNU_const_index: // 0xfc 1 ULEB128 index |
339 | data.Skip_LEB128(offset_ptr: &offset); |
340 | return offset - data_offset; |
341 | |
342 | // All opcodes that have a 2 ULEB (signed or unsigned) arguments |
343 | case DW_OP_bregx: // 0x92 2 ULEB128 register followed by SLEB128 offset |
344 | case DW_OP_bit_piece: // 0x9d ULEB128 bit size, ULEB128 bit offset (DWARF3); |
345 | case DW_OP_regval_type: // 0xa5 ULEB128 + ULEB128 |
346 | data.Skip_LEB128(offset_ptr: &offset); |
347 | data.Skip_LEB128(offset_ptr: &offset); |
348 | return offset - data_offset; |
349 | |
350 | case DW_OP_implicit_value: // 0x9e ULEB128 size followed by block of that size |
351 | // (DWARF4) |
352 | { |
353 | uint64_t block_len = data.Skip_LEB128(offset_ptr: &offset); |
354 | offset += block_len; |
355 | return offset - data_offset; |
356 | } |
357 | |
358 | case DW_OP_implicit_pointer: // 0xa0 4-byte (or 8-byte for DWARF 64) constant |
359 | // + LEB128 |
360 | { |
361 | data.Skip_LEB128(offset_ptr: &offset); |
362 | return (dwarf_cu ? dwarf_cu->GetAddressByteSize() : 4) + offset - |
363 | data_offset; |
364 | } |
365 | |
366 | case DW_OP_GNU_entry_value: |
367 | case DW_OP_entry_value: // 0xa3 ULEB128 size + variable-length block |
368 | { |
369 | uint64_t subexpr_len = data.GetULEB128(offset_ptr: &offset); |
370 | return (offset - data_offset) + subexpr_len; |
371 | } |
372 | |
373 | case DW_OP_const_type: // 0xa4 ULEB128 + size + variable-length block |
374 | { |
375 | data.Skip_LEB128(offset_ptr: &offset); |
376 | uint8_t length = data.GetU8(offset_ptr: &offset); |
377 | return (offset - data_offset) + length; |
378 | } |
379 | |
380 | case DW_OP_LLVM_user: // 0xe9: ULEB128 + variable length constant |
381 | { |
382 | uint64_t constants = data.GetULEB128(offset_ptr: &offset); |
383 | return (offset - data_offset) + constants; |
384 | } |
385 | } |
386 | |
387 | if (dwarf_cu) |
388 | return dwarf_cu->GetVendorDWARFOpcodeSize(data, data_offset, op); |
389 | |
390 | return LLDB_INVALID_OFFSET; |
391 | } |
392 | |
393 | static const char *DW_OP_value_to_name(uint32_t val) { |
394 | static char invalid[100]; |
395 | llvm::StringRef llvmstr = llvm::dwarf::OperationEncodingString(Encoding: val); |
396 | if (llvmstr.empty()) { |
397 | snprintf(s: invalid, maxlen: sizeof(invalid), format: "Unknown DW_OP constant: 0x%x", val); |
398 | return invalid; |
399 | } |
400 | return llvmstr.data(); |
401 | } |
402 | |
403 | llvm::Expected<lldb::addr_t> DWARFExpression::GetLocation_DW_OP_addr( |
404 | const DWARFExpression::Delegate *dwarf_cu) const { |
405 | lldb::offset_t offset = 0; |
406 | while (m_data.ValidOffset(offset)) { |
407 | const LocationAtom op = static_cast<LocationAtom>(m_data.GetU8(offset_ptr: &offset)); |
408 | |
409 | if (op == DW_OP_addr) |
410 | return m_data.GetAddress(offset_ptr: &offset); |
411 | |
412 | if (op == DW_OP_GNU_addr_index || op == DW_OP_addrx) { |
413 | const uint64_t index = m_data.GetULEB128(offset_ptr: &offset); |
414 | if (dwarf_cu) |
415 | return dwarf_cu->ReadAddressFromDebugAddrSection(index); |
416 | return llvm::createStringError(Fmt: "cannot evaluate %s without a DWARF unit", |
417 | Vals: DW_OP_value_to_name(val: op)); |
418 | } |
419 | |
420 | const lldb::offset_t op_arg_size = |
421 | GetOpcodeDataSize(data: m_data, data_offset: offset, op, dwarf_cu); |
422 | if (op_arg_size == LLDB_INVALID_OFFSET) |
423 | return llvm::createStringError(Fmt: "cannot get opcode data size for %s", |
424 | Vals: DW_OP_value_to_name(val: op)); |
425 | |
426 | offset += op_arg_size; |
427 | } |
428 | |
429 | return LLDB_INVALID_ADDRESS; |
430 | } |
431 | |
432 | bool DWARFExpression::Update_DW_OP_addr( |
433 | const DWARFExpression::Delegate *dwarf_cu, lldb::addr_t file_addr) { |
434 | lldb::offset_t offset = 0; |
435 | while (m_data.ValidOffset(offset)) { |
436 | const LocationAtom op = static_cast<LocationAtom>(m_data.GetU8(offset_ptr: &offset)); |
437 | |
438 | if (op == DW_OP_addr) { |
439 | const uint32_t addr_byte_size = m_data.GetAddressByteSize(); |
440 | // We have to make a copy of the data as we don't know if this data is |
441 | // from a read only memory mapped buffer, so we duplicate all of the data |
442 | // first, then modify it, and if all goes well, we then replace the data |
443 | // for this expression |
444 | |
445 | // Make en encoder that contains a copy of the location expression data |
446 | // so we can write the address into the buffer using the correct byte |
447 | // order. |
448 | DataEncoder encoder(m_data.GetDataStart(), m_data.GetByteSize(), |
449 | m_data.GetByteOrder(), addr_byte_size); |
450 | |
451 | // Replace the address in the new buffer |
452 | if (encoder.PutAddress(offset, addr: file_addr) == UINT32_MAX) |
453 | return false; |
454 | |
455 | // All went well, so now we can reset the data using a shared pointer to |
456 | // the heap data so "m_data" will now correctly manage the heap data. |
457 | m_data.SetData(data_sp: encoder.GetDataBuffer()); |
458 | return true; |
459 | } |
460 | if (op == DW_OP_addrx) { |
461 | // Replace DW_OP_addrx with DW_OP_addr, since we can't modify the |
462 | // read-only debug_addr table. |
463 | // Subtract one to account for the opcode. |
464 | llvm::ArrayRef data_before_op = m_data.GetData().take_front(N: offset - 1); |
465 | |
466 | // Read the addrx index to determine how many bytes it needs. |
467 | const lldb::offset_t old_offset = offset; |
468 | m_data.GetULEB128(offset_ptr: &offset); |
469 | if (old_offset == offset) |
470 | return false; |
471 | llvm::ArrayRef data_after_op = m_data.GetData().drop_front(N: offset); |
472 | |
473 | DataEncoder encoder(m_data.GetByteOrder(), m_data.GetAddressByteSize()); |
474 | encoder.AppendData(data: data_before_op); |
475 | encoder.AppendU8(value: DW_OP_addr); |
476 | encoder.AppendAddress(addr: file_addr); |
477 | encoder.AppendData(data: data_after_op); |
478 | m_data.SetData(data_sp: encoder.GetDataBuffer()); |
479 | return true; |
480 | } |
481 | const lldb::offset_t op_arg_size = |
482 | GetOpcodeDataSize(data: m_data, data_offset: offset, op, dwarf_cu); |
483 | if (op_arg_size == LLDB_INVALID_OFFSET) |
484 | break; |
485 | offset += op_arg_size; |
486 | } |
487 | return false; |
488 | } |
489 | |
490 | bool DWARFExpression::ContainsThreadLocalStorage( |
491 | const DWARFExpression::Delegate *dwarf_cu) const { |
492 | lldb::offset_t offset = 0; |
493 | while (m_data.ValidOffset(offset)) { |
494 | const LocationAtom op = static_cast<LocationAtom>(m_data.GetU8(offset_ptr: &offset)); |
495 | |
496 | if (op == DW_OP_form_tls_address || op == DW_OP_GNU_push_tls_address) |
497 | return true; |
498 | const lldb::offset_t op_arg_size = |
499 | GetOpcodeDataSize(data: m_data, data_offset: offset, op, dwarf_cu); |
500 | if (op_arg_size == LLDB_INVALID_OFFSET) |
501 | return false; |
502 | offset += op_arg_size; |
503 | } |
504 | return false; |
505 | } |
506 | bool DWARFExpression::LinkThreadLocalStorage( |
507 | const DWARFExpression::Delegate *dwarf_cu, |
508 | std::function<lldb::addr_t(lldb::addr_t file_addr)> const |
509 | &link_address_callback) { |
510 | const uint32_t addr_byte_size = m_data.GetAddressByteSize(); |
511 | // We have to make a copy of the data as we don't know if this data is from a |
512 | // read only memory mapped buffer, so we duplicate all of the data first, |
513 | // then modify it, and if all goes well, we then replace the data for this |
514 | // expression. |
515 | // Make en encoder that contains a copy of the location expression data so we |
516 | // can write the address into the buffer using the correct byte order. |
517 | DataEncoder encoder(m_data.GetDataStart(), m_data.GetByteSize(), |
518 | m_data.GetByteOrder(), addr_byte_size); |
519 | |
520 | lldb::offset_t offset = 0; |
521 | lldb::offset_t const_offset = 0; |
522 | lldb::addr_t const_value = 0; |
523 | size_t const_byte_size = 0; |
524 | while (m_data.ValidOffset(offset)) { |
525 | const LocationAtom op = static_cast<LocationAtom>(m_data.GetU8(offset_ptr: &offset)); |
526 | |
527 | bool decoded_data = false; |
528 | switch (op) { |
529 | case DW_OP_const4u: |
530 | // Remember the const offset in case we later have a |
531 | // DW_OP_form_tls_address or DW_OP_GNU_push_tls_address |
532 | const_offset = offset; |
533 | const_value = m_data.GetU32(offset_ptr: &offset); |
534 | decoded_data = true; |
535 | const_byte_size = 4; |
536 | break; |
537 | |
538 | case DW_OP_const8u: |
539 | // Remember the const offset in case we later have a |
540 | // DW_OP_form_tls_address or DW_OP_GNU_push_tls_address |
541 | const_offset = offset; |
542 | const_value = m_data.GetU64(offset_ptr: &offset); |
543 | decoded_data = true; |
544 | const_byte_size = 8; |
545 | break; |
546 | |
547 | case DW_OP_form_tls_address: |
548 | case DW_OP_GNU_push_tls_address: |
549 | // DW_OP_form_tls_address and DW_OP_GNU_push_tls_address must be preceded |
550 | // by a file address on the stack. We assume that DW_OP_const4u or |
551 | // DW_OP_const8u is used for these values, and we check that the last |
552 | // opcode we got before either of these was DW_OP_const4u or |
553 | // DW_OP_const8u. If so, then we can link the value accordingly. For |
554 | // Darwin, the value in the DW_OP_const4u or DW_OP_const8u is the file |
555 | // address of a structure that contains a function pointer, the pthread |
556 | // key and the offset into the data pointed to by the pthread key. So we |
557 | // must link this address and also set the module of this expression to |
558 | // the new_module_sp so we can resolve the file address correctly |
559 | if (const_byte_size > 0) { |
560 | lldb::addr_t linked_file_addr = link_address_callback(const_value); |
561 | if (linked_file_addr == LLDB_INVALID_ADDRESS) |
562 | return false; |
563 | // Replace the address in the new buffer |
564 | if (encoder.PutUnsigned(offset: const_offset, byte_size: const_byte_size, |
565 | value: linked_file_addr) == UINT32_MAX) |
566 | return false; |
567 | } |
568 | break; |
569 | |
570 | default: |
571 | const_offset = 0; |
572 | const_value = 0; |
573 | const_byte_size = 0; |
574 | break; |
575 | } |
576 | |
577 | if (!decoded_data) { |
578 | const lldb::offset_t op_arg_size = |
579 | GetOpcodeDataSize(data: m_data, data_offset: offset, op, dwarf_cu); |
580 | if (op_arg_size == LLDB_INVALID_OFFSET) |
581 | return false; |
582 | else |
583 | offset += op_arg_size; |
584 | } |
585 | } |
586 | |
587 | m_data.SetData(data_sp: encoder.GetDataBuffer()); |
588 | return true; |
589 | } |
590 | |
591 | static llvm::Error Evaluate_DW_OP_entry_value(std::vector<Value> &stack, |
592 | ExecutionContext *exe_ctx, |
593 | RegisterContext *reg_ctx, |
594 | const DataExtractor &opcodes, |
595 | lldb::offset_t &opcode_offset, |
596 | Log *log) { |
597 | // DW_OP_entry_value(sub-expr) describes the location a variable had upon |
598 | // function entry: this variable location is presumed to be optimized out at |
599 | // the current PC value. The caller of the function may have call site |
600 | // information that describes an alternate location for the variable (e.g. a |
601 | // constant literal, or a spilled stack value) in the parent frame. |
602 | // |
603 | // Example (this is pseudo-code & pseudo-DWARF, but hopefully illustrative): |
604 | // |
605 | // void child(int &sink, int x) { |
606 | // ... |
607 | // /* "x" gets optimized out. */ |
608 | // |
609 | // /* The location of "x" here is: DW_OP_entry_value($reg2). */ |
610 | // ++sink; |
611 | // } |
612 | // |
613 | // void parent() { |
614 | // int sink; |
615 | // |
616 | // /* |
617 | // * The callsite information emitted here is: |
618 | // * |
619 | // * DW_TAG_call_site |
620 | // * DW_AT_return_pc ... (for "child(sink, 123);") |
621 | // * DW_TAG_call_site_parameter (for "sink") |
622 | // * DW_AT_location ($reg1) |
623 | // * DW_AT_call_value ($SP - 8) |
624 | // * DW_TAG_call_site_parameter (for "x") |
625 | // * DW_AT_location ($reg2) |
626 | // * DW_AT_call_value ($literal 123) |
627 | // * |
628 | // * DW_TAG_call_site |
629 | // * DW_AT_return_pc ... (for "child(sink, 456);") |
630 | // * ... |
631 | // */ |
632 | // child(sink, 123); |
633 | // child(sink, 456); |
634 | // } |
635 | // |
636 | // When the program stops at "++sink" within `child`, the debugger determines |
637 | // the call site by analyzing the return address. Once the call site is found, |
638 | // the debugger determines which parameter is referenced by DW_OP_entry_value |
639 | // and evaluates the corresponding location for that parameter in `parent`. |
640 | |
641 | // 1. Find the function which pushed the current frame onto the stack. |
642 | if ((!exe_ctx || !exe_ctx->HasTargetScope()) || !reg_ctx) { |
643 | return llvm::createStringError(Fmt: "no exe/reg context"); |
644 | } |
645 | |
646 | StackFrame *current_frame = exe_ctx->GetFramePtr(); |
647 | Thread *thread = exe_ctx->GetThreadPtr(); |
648 | if (!current_frame || !thread) |
649 | return llvm::createStringError(Fmt: "no current frame/thread"); |
650 | |
651 | Target &target = exe_ctx->GetTargetRef(); |
652 | StackFrameSP parent_frame = nullptr; |
653 | addr_t return_pc = LLDB_INVALID_ADDRESS; |
654 | uint32_t current_frame_idx = current_frame->GetFrameIndex(); |
655 | |
656 | for (uint32_t parent_frame_idx = current_frame_idx + 1;;parent_frame_idx++) { |
657 | parent_frame = thread->GetStackFrameAtIndex(idx: parent_frame_idx); |
658 | // If this is null, we're at the end of the stack. |
659 | if (!parent_frame) |
660 | break; |
661 | |
662 | // Record the first valid return address, even if this is an inlined frame, |
663 | // in order to look up the associated call edge in the first non-inlined |
664 | // parent frame. |
665 | if (return_pc == LLDB_INVALID_ADDRESS) { |
666 | return_pc = parent_frame->GetFrameCodeAddress().GetLoadAddress(target: &target); |
667 | LLDB_LOG(log, "immediate ancestor with pc = {0:x}", return_pc); |
668 | } |
669 | |
670 | // If we've found an inlined frame, skip it (these have no call site |
671 | // parameters). |
672 | if (parent_frame->IsInlined()) |
673 | continue; |
674 | |
675 | // We've found the first non-inlined parent frame. |
676 | break; |
677 | } |
678 | if (!parent_frame || !parent_frame->GetRegisterContext()) { |
679 | return llvm::createStringError(Fmt: "no parent frame with reg ctx"); |
680 | } |
681 | |
682 | Function *parent_func = |
683 | parent_frame->GetSymbolContext(resolve_scope: eSymbolContextFunction).function; |
684 | if (!parent_func) |
685 | return llvm::createStringError(Fmt: "no parent function"); |
686 | |
687 | // 2. Find the call edge in the parent function responsible for creating the |
688 | // current activation. |
689 | Function *current_func = |
690 | current_frame->GetSymbolContext(resolve_scope: eSymbolContextFunction).function; |
691 | if (!current_func) |
692 | return llvm::createStringError(Fmt: "no current function"); |
693 | |
694 | CallEdge *call_edge = nullptr; |
695 | ModuleList &modlist = target.GetImages(); |
696 | ExecutionContext parent_exe_ctx = *exe_ctx; |
697 | parent_exe_ctx.SetFrameSP(parent_frame); |
698 | if (!parent_frame->IsArtificial()) { |
699 | // If the parent frame is not artificial, the current activation may be |
700 | // produced by an ambiguous tail call. In this case, refuse to proceed. |
701 | call_edge = parent_func->GetCallEdgeForReturnAddress(return_pc, target); |
702 | if (!call_edge) { |
703 | return llvm::createStringError( |
704 | S: llvm::formatv(Fmt: "no call edge for retn-pc = {0:x} in parent frame {1}", |
705 | Vals&: return_pc, Vals: parent_func->GetName())); |
706 | } |
707 | Function *callee_func = call_edge->GetCallee(images&: modlist, exe_ctx&: parent_exe_ctx); |
708 | if (callee_func != current_func) { |
709 | return llvm::createStringError( |
710 | Fmt: "ambiguous call sequence, can't find real parent frame"); |
711 | } |
712 | } else { |
713 | // The StackFrameList solver machinery has deduced that an unambiguous tail |
714 | // call sequence that produced the current activation. The first edge in |
715 | // the parent that points to the current function must be valid. |
716 | for (auto &edge : parent_func->GetTailCallingEdges()) { |
717 | if (edge->GetCallee(images&: modlist, exe_ctx&: parent_exe_ctx) == current_func) { |
718 | call_edge = edge.get(); |
719 | break; |
720 | } |
721 | } |
722 | } |
723 | if (!call_edge) |
724 | return llvm::createStringError(Fmt: "no unambiguous edge from parent " |
725 | "to current function"); |
726 | |
727 | // 3. Attempt to locate the DW_OP_entry_value expression in the set of |
728 | // available call site parameters. If found, evaluate the corresponding |
729 | // parameter in the context of the parent frame. |
730 | const uint32_t subexpr_len = opcodes.GetULEB128(offset_ptr: &opcode_offset); |
731 | const void *subexpr_data = opcodes.GetData(offset_ptr: &opcode_offset, length: subexpr_len); |
732 | if (!subexpr_data) |
733 | return llvm::createStringError(Fmt: "subexpr could not be read"); |
734 | |
735 | const CallSiteParameter *matched_param = nullptr; |
736 | for (const CallSiteParameter ¶m : call_edge->GetCallSiteParameters()) { |
737 | DataExtractor param_subexpr_extractor; |
738 | if (!param.LocationInCallee.GetExpressionData(data&: param_subexpr_extractor)) |
739 | continue; |
740 | lldb::offset_t param_subexpr_offset = 0; |
741 | const void *param_subexpr_data = |
742 | param_subexpr_extractor.GetData(offset_ptr: ¶m_subexpr_offset, length: subexpr_len); |
743 | if (!param_subexpr_data || |
744 | param_subexpr_extractor.BytesLeft(offset: param_subexpr_offset) != 0) |
745 | continue; |
746 | |
747 | // At this point, the DW_OP_entry_value sub-expression and the callee-side |
748 | // expression in the call site parameter are known to have the same length. |
749 | // Check whether they are equal. |
750 | // |
751 | // Note that an equality check is sufficient: the contents of the |
752 | // DW_OP_entry_value subexpression are only used to identify the right call |
753 | // site parameter in the parent, and do not require any special handling. |
754 | if (memcmp(s1: subexpr_data, s2: param_subexpr_data, n: subexpr_len) == 0) { |
755 | matched_param = ¶m; |
756 | break; |
757 | } |
758 | } |
759 | if (!matched_param) |
760 | return llvm::createStringError(Fmt: "no matching call site param found"); |
761 | |
762 | // TODO: Add support for DW_OP_push_object_address within a DW_OP_entry_value |
763 | // subexpresion whenever llvm does. |
764 | const DWARFExpressionList ¶m_expr = matched_param->LocationInCaller; |
765 | |
766 | llvm::Expected<Value> maybe_result = param_expr.Evaluate( |
767 | exe_ctx: &parent_exe_ctx, reg_ctx: parent_frame->GetRegisterContext().get(), |
768 | LLDB_INVALID_ADDRESS, |
769 | /*initial_value_ptr=*/nullptr, |
770 | /*object_address_ptr=*/nullptr); |
771 | if (!maybe_result) { |
772 | LLDB_LOG(log, |
773 | "Evaluate_DW_OP_entry_value: call site param evaluation failed"); |
774 | return maybe_result.takeError(); |
775 | } |
776 | |
777 | stack.push_back(x: *maybe_result); |
778 | return llvm::Error::success(); |
779 | } |
780 | |
781 | namespace { |
782 | /// The location description kinds described by the DWARF v5 |
783 | /// specification. Composite locations are handled out-of-band and |
784 | /// thus aren't part of the enum. |
785 | enum LocationDescriptionKind { |
786 | Empty, |
787 | Memory, |
788 | Register, |
789 | Implicit |
790 | /* Composite*/ |
791 | }; |
792 | /// Adjust value's ValueType according to the kind of location description. |
793 | void UpdateValueTypeFromLocationDescription( |
794 | Log *log, const DWARFExpression::Delegate *dwarf_cu, |
795 | LocationDescriptionKind kind, Value *value = nullptr) { |
796 | // Note that this function is conflating DWARF expressions with |
797 | // DWARF location descriptions. Perhaps it would be better to define |
798 | // a wrapper for DWARFExpression::Eval() that deals with DWARF |
799 | // location descriptions (which consist of one or more DWARF |
800 | // expressions). But doing this would mean we'd also need factor the |
801 | // handling of DW_OP_(bit_)piece out of this function. |
802 | if (dwarf_cu && dwarf_cu->GetVersion() >= 4) { |
803 | const char *log_msg = "DWARF location description kind: %s"; |
804 | switch (kind) { |
805 | case Empty: |
806 | LLDB_LOGF(log, log_msg, "Empty"); |
807 | break; |
808 | case Memory: |
809 | LLDB_LOGF(log, log_msg, "Memory"); |
810 | if (value->GetValueType() == Value::ValueType::Scalar) |
811 | value->SetValueType(Value::ValueType::LoadAddress); |
812 | break; |
813 | case Register: |
814 | LLDB_LOGF(log, log_msg, "Register"); |
815 | value->SetValueType(Value::ValueType::Scalar); |
816 | break; |
817 | case Implicit: |
818 | LLDB_LOGF(log, log_msg, "Implicit"); |
819 | if (value->GetValueType() == Value::ValueType::LoadAddress) |
820 | value->SetValueType(Value::ValueType::Scalar); |
821 | break; |
822 | } |
823 | } |
824 | } |
825 | } // namespace |
826 | |
827 | /// Helper function to move common code used to resolve a file address and turn |
828 | /// into a load address. |
829 | /// |
830 | /// \param exe_ctx Pointer to the execution context |
831 | /// \param module_sp shared_ptr contains the module if we have one |
832 | /// \param dw_op_type C-style string used to vary the error output |
833 | /// \param file_addr the file address we are trying to resolve and turn into a |
834 | /// load address |
835 | /// \param so_addr out parameter, will be set to load address or section offset |
836 | /// \param check_sectionoffset bool which determines if having a section offset |
837 | /// but not a load address is considerd a success |
838 | /// \returns std::optional containing the load address if resolving and getting |
839 | /// the load address succeed or an empty Optinal otherwise. If |
840 | /// check_sectionoffset is true we consider LLDB_INVALID_ADDRESS a |
841 | /// success if so_addr.IsSectionOffset() is true. |
842 | static llvm::Expected<lldb::addr_t> |
843 | ResolveLoadAddress(ExecutionContext *exe_ctx, lldb::ModuleSP &module_sp, |
844 | const char *dw_op_type, lldb::addr_t file_addr, |
845 | Address &so_addr, bool check_sectionoffset = false) { |
846 | if (!module_sp) |
847 | return llvm::createStringError(Fmt: "need module to resolve file address for %s", |
848 | Vals: dw_op_type); |
849 | |
850 | if (!module_sp->ResolveFileAddress(vm_addr: file_addr, so_addr)) |
851 | return llvm::createStringError(Fmt: "failed to resolve file address in module"); |
852 | |
853 | const addr_t load_addr = so_addr.GetLoadAddress(target: exe_ctx->GetTargetPtr()); |
854 | |
855 | if (load_addr == LLDB_INVALID_ADDRESS && |
856 | (check_sectionoffset && !so_addr.IsSectionOffset())) |
857 | return llvm::createStringError(Fmt: "failed to resolve load address"); |
858 | |
859 | return load_addr; |
860 | } |
861 | |
862 | /// Helper function to move common code used to load sized data from a uint8_t |
863 | /// buffer. |
864 | /// |
865 | /// \param addr_bytes uint8_t buffer containg raw data |
866 | /// \param size_addr_bytes how large is the underlying raw data |
867 | /// \param byte_order what is the byter order of the underlyig data |
868 | /// \param size How much of the underlying data we want to use |
869 | /// \return The underlying data converted into a Scalar |
870 | static Scalar DerefSizeExtractDataHelper(uint8_t *addr_bytes, |
871 | size_t size_addr_bytes, |
872 | ByteOrder byte_order, size_t size) { |
873 | DataExtractor addr_data(addr_bytes, size_addr_bytes, byte_order, size); |
874 | |
875 | lldb::offset_t addr_data_offset = 0; |
876 | if (size <= 8) |
877 | return addr_data.GetMaxU64(offset_ptr: &addr_data_offset, byte_size: size); |
878 | else |
879 | return addr_data.GetAddress(offset_ptr: &addr_data_offset); |
880 | } |
881 | |
882 | llvm::Expected<Value> DWARFExpression::Evaluate( |
883 | ExecutionContext *exe_ctx, RegisterContext *reg_ctx, |
884 | lldb::ModuleSP module_sp, const DataExtractor &opcodes, |
885 | const DWARFExpression::Delegate *dwarf_cu, |
886 | const lldb::RegisterKind reg_kind, const Value *initial_value_ptr, |
887 | const Value *object_address_ptr) { |
888 | |
889 | if (opcodes.GetByteSize() == 0) |
890 | return llvm::createStringError( |
891 | Fmt: "no location, value may have been optimized out"); |
892 | std::vector<Value> stack; |
893 | |
894 | Process *process = nullptr; |
895 | StackFrame *frame = nullptr; |
896 | Target *target = nullptr; |
897 | |
898 | if (exe_ctx) { |
899 | process = exe_ctx->GetProcessPtr(); |
900 | frame = exe_ctx->GetFramePtr(); |
901 | target = exe_ctx->GetTargetPtr(); |
902 | } |
903 | if (reg_ctx == nullptr && frame) |
904 | reg_ctx = frame->GetRegisterContext().get(); |
905 | |
906 | if (initial_value_ptr) |
907 | stack.push_back(x: *initial_value_ptr); |
908 | |
909 | lldb::offset_t offset = 0; |
910 | Value tmp; |
911 | uint32_t reg_num; |
912 | |
913 | /// Insertion point for evaluating multi-piece expression. |
914 | uint64_t op_piece_offset = 0; |
915 | Value pieces; // Used for DW_OP_piece |
916 | |
917 | Log *log = GetLog(mask: LLDBLog::Expressions); |
918 | // A generic type is "an integral type that has the size of an address and an |
919 | // unspecified signedness". For now, just use the signedness of the operand. |
920 | // TODO: Implement a real typed stack, and store the genericness of the value |
921 | // there. |
922 | auto to_generic = [&](auto v) { |
923 | // TODO: Avoid implicit trunc? |
924 | // See https://github.com/llvm/llvm-project/issues/112510. |
925 | bool is_signed = std::is_signed<decltype(v)>::value; |
926 | return Scalar(llvm::APSInt(llvm::APInt(8 * opcodes.GetAddressByteSize(), v, |
927 | is_signed, /*implicitTrunc=*/true), |
928 | !is_signed)); |
929 | }; |
930 | |
931 | // The default kind is a memory location. This is updated by any |
932 | // operation that changes this, such as DW_OP_stack_value, and reset |
933 | // by composition operations like DW_OP_piece. |
934 | LocationDescriptionKind dwarf4_location_description_kind = Memory; |
935 | |
936 | while (opcodes.ValidOffset(offset)) { |
937 | const lldb::offset_t op_offset = offset; |
938 | const uint8_t op = opcodes.GetU8(offset_ptr: &offset); |
939 | |
940 | if (log && log->GetVerbose()) { |
941 | size_t count = stack.size(); |
942 | LLDB_LOGF(log, "Stack before operation has %"PRIu64 " values:", |
943 | (uint64_t)count); |
944 | for (size_t i = 0; i < count; ++i) { |
945 | StreamString new_value; |
946 | new_value.Printf(format: "[%"PRIu64 "]", (uint64_t)i); |
947 | stack[i].Dump(strm: &new_value); |
948 | LLDB_LOGF(log, " %s", new_value.GetData()); |
949 | } |
950 | LLDB_LOGF(log, "0x%8.8"PRIx64 ": %s", op_offset, |
951 | DW_OP_value_to_name(op)); |
952 | } |
953 | |
954 | if (std::optional<unsigned> arity = |
955 | llvm::dwarf::OperationArity(O: static_cast<LocationAtom>(op))) { |
956 | if (stack.size() < *arity) |
957 | return llvm::createStringError( |
958 | Fmt: "%s needs at least %d stack entries (stack has %d entries)", |
959 | Vals: DW_OP_value_to_name(val: op), Vals: *arity, Vals: stack.size()); |
960 | } |
961 | |
962 | switch (op) { |
963 | // The DW_OP_addr operation has a single operand that encodes a machine |
964 | // address and whose size is the size of an address on the target machine. |
965 | case DW_OP_addr: |
966 | stack.push_back(x: Scalar(opcodes.GetAddress(offset_ptr: &offset))); |
967 | if (target && |
968 | target->GetArchitecture().GetCore() == ArchSpec::eCore_wasm32) { |
969 | // wasm file sections aren't mapped into memory, therefore addresses can |
970 | // never point into a file section and are always LoadAddresses. |
971 | stack.back().SetValueType(Value::ValueType::LoadAddress); |
972 | } else { |
973 | stack.back().SetValueType(Value::ValueType::FileAddress); |
974 | } |
975 | break; |
976 | |
977 | // The DW_OP_addr_sect_offset4 is used for any location expressions in |
978 | // shared libraries that have a location like: |
979 | // DW_OP_addr(0x1000) |
980 | // If this address resides in a shared library, then this virtual address |
981 | // won't make sense when it is evaluated in the context of a running |
982 | // process where shared libraries have been slid. To account for this, this |
983 | // new address type where we can store the section pointer and a 4 byte |
984 | // offset. |
985 | // case DW_OP_addr_sect_offset4: |
986 | // { |
987 | // result_type = eResultTypeFileAddress; |
988 | // lldb::Section *sect = (lldb::Section |
989 | // *)opcodes.GetMaxU64(&offset, sizeof(void *)); |
990 | // lldb::addr_t sect_offset = opcodes.GetU32(&offset); |
991 | // |
992 | // Address so_addr (sect, sect_offset); |
993 | // lldb::addr_t load_addr = so_addr.GetLoadAddress(); |
994 | // if (load_addr != LLDB_INVALID_ADDRESS) |
995 | // { |
996 | // // We successfully resolve a file address to a load |
997 | // // address. |
998 | // stack.push_back(load_addr); |
999 | // break; |
1000 | // } |
1001 | // else |
1002 | // { |
1003 | // // We were able |
1004 | // if (error_ptr) |
1005 | // error_ptr->SetErrorStringWithFormat ("Section %s in |
1006 | // %s is not currently loaded.\n", |
1007 | // sect->GetName().AsCString(), |
1008 | // sect->GetModule()->GetFileSpec().GetFilename().AsCString()); |
1009 | // return false; |
1010 | // } |
1011 | // } |
1012 | // break; |
1013 | |
1014 | // OPCODE: DW_OP_deref |
1015 | // OPERANDS: none |
1016 | // DESCRIPTION: Pops the top stack entry and treats it as an address. |
1017 | // The value retrieved from that address is pushed. The size of the data |
1018 | // retrieved from the dereferenced address is the size of an address on the |
1019 | // target machine. |
1020 | case DW_OP_deref: { |
1021 | if (stack.empty()) |
1022 | return llvm::createStringError( |
1023 | Fmt: "expression stack empty for DW_OP_deref"); |
1024 | Value::ValueType value_type = stack.back().GetValueType(); |
1025 | switch (value_type) { |
1026 | case Value::ValueType::HostAddress: { |
1027 | void *src = (void *)stack.back().GetScalar().ULongLong(); |
1028 | intptr_t ptr; |
1029 | ::memcpy(dest: &ptr, src: src, n: sizeof(void *)); |
1030 | stack.back().GetScalar() = ptr; |
1031 | stack.back().ClearContext(); |
1032 | } break; |
1033 | case Value::ValueType::FileAddress: { |
1034 | auto file_addr = stack.back().GetScalar().ULongLong( |
1035 | LLDB_INVALID_ADDRESS); |
1036 | |
1037 | Address so_addr; |
1038 | auto maybe_load_addr = ResolveLoadAddress( |
1039 | exe_ctx, module_sp, dw_op_type: "DW_OP_deref", file_addr, so_addr); |
1040 | |
1041 | if (!maybe_load_addr) |
1042 | return maybe_load_addr.takeError(); |
1043 | |
1044 | stack.back().GetScalar() = *maybe_load_addr; |
1045 | // Fall through to load address promotion code below. |
1046 | } |
1047 | [[fallthrough]]; |
1048 | case Value::ValueType::Scalar: |
1049 | // Promote Scalar to LoadAddress and fall through. |
1050 | stack.back().SetValueType(Value::ValueType::LoadAddress); |
1051 | [[fallthrough]]; |
1052 | case Value::ValueType::LoadAddress: |
1053 | if (exe_ctx) { |
1054 | if (process) { |
1055 | lldb::addr_t pointer_addr = |
1056 | stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS); |
1057 | Status error; |
1058 | lldb::addr_t pointer_value = |
1059 | process->ReadPointerFromMemory(vm_addr: pointer_addr, error); |
1060 | if (pointer_value != LLDB_INVALID_ADDRESS) { |
1061 | if (ABISP abi_sp = process->GetABI()) |
1062 | pointer_value = abi_sp->FixCodeAddress(pc: pointer_value); |
1063 | stack.back().GetScalar() = pointer_value; |
1064 | stack.back().ClearContext(); |
1065 | } else { |
1066 | return llvm::createStringError( |
1067 | Fmt: "Failed to dereference pointer from 0x%"PRIx64 |
1068 | " for DW_OP_deref: %s\n", |
1069 | Vals: pointer_addr, Vals: error.AsCString()); |
1070 | } |
1071 | } else { |
1072 | return llvm::createStringError(Fmt: "NULL process for DW_OP_deref"); |
1073 | } |
1074 | } else { |
1075 | return llvm::createStringError( |
1076 | Fmt: "NULL execution context for DW_OP_deref"); |
1077 | } |
1078 | break; |
1079 | |
1080 | case Value::ValueType::Invalid: |
1081 | return llvm::createStringError(Fmt: "invalid value type for DW_OP_deref"); |
1082 | } |
1083 | |
1084 | } break; |
1085 | |
1086 | // OPCODE: DW_OP_deref_size |
1087 | // OPERANDS: 1 |
1088 | // 1 - uint8_t that specifies the size of the data to dereference. |
1089 | // DESCRIPTION: Behaves like the DW_OP_deref operation: it pops the top |
1090 | // stack entry and treats it as an address. The value retrieved from that |
1091 | // address is pushed. In the DW_OP_deref_size operation, however, the size |
1092 | // in bytes of the data retrieved from the dereferenced address is |
1093 | // specified by the single operand. This operand is a 1-byte unsigned |
1094 | // integral constant whose value may not be larger than the size of an |
1095 | // address on the target machine. The data retrieved is zero extended to |
1096 | // the size of an address on the target machine before being pushed on the |
1097 | // expression stack. |
1098 | case DW_OP_deref_size: { |
1099 | if (stack.empty()) { |
1100 | return llvm::createStringError( |
1101 | Fmt: "expression stack empty for DW_OP_deref_size"); |
1102 | } |
1103 | uint8_t size = opcodes.GetU8(offset_ptr: &offset); |
1104 | if (size > 8) { |
1105 | return llvm::createStringError( |
1106 | Fmt: "Invalid address size for DW_OP_deref_size: %d\n", Vals: size); |
1107 | } |
1108 | Value::ValueType value_type = stack.back().GetValueType(); |
1109 | switch (value_type) { |
1110 | case Value::ValueType::HostAddress: { |
1111 | void *src = (void *)stack.back().GetScalar().ULongLong(); |
1112 | intptr_t ptr; |
1113 | ::memcpy(dest: &ptr, src: src, n: sizeof(void *)); |
1114 | // I can't decide whether the size operand should apply to the bytes in |
1115 | // their |
1116 | // lldb-host endianness or the target endianness.. I doubt this'll ever |
1117 | // come up but I'll opt for assuming big endian regardless. |
1118 | switch (size) { |
1119 | case 1: |
1120 | ptr = ptr & 0xff; |
1121 | break; |
1122 | case 2: |
1123 | ptr = ptr & 0xffff; |
1124 | break; |
1125 | case 3: |
1126 | ptr = ptr & 0xffffff; |
1127 | break; |
1128 | case 4: |
1129 | ptr = ptr & 0xffffffff; |
1130 | break; |
1131 | // the casts are added to work around the case where intptr_t is a 32 |
1132 | // bit quantity; |
1133 | // presumably we won't hit the 5..7 cases if (void*) is 32-bits in this |
1134 | // program. |
1135 | case 5: |
1136 | ptr = (intptr_t)ptr & 0xffffffffffULL; |
1137 | break; |
1138 | case 6: |
1139 | ptr = (intptr_t)ptr & 0xffffffffffffULL; |
1140 | break; |
1141 | case 7: |
1142 | ptr = (intptr_t)ptr & 0xffffffffffffffULL; |
1143 | break; |
1144 | default: |
1145 | break; |
1146 | } |
1147 | stack.back().GetScalar() = ptr; |
1148 | stack.back().ClearContext(); |
1149 | } break; |
1150 | case Value::ValueType::FileAddress: { |
1151 | auto file_addr = |
1152 | stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS); |
1153 | Address so_addr; |
1154 | auto maybe_load_addr = ResolveLoadAddress( |
1155 | exe_ctx, module_sp, dw_op_type: "DW_OP_deref_size", file_addr, so_addr, |
1156 | /*check_sectionoffset=*/true); |
1157 | |
1158 | if (!maybe_load_addr) |
1159 | return maybe_load_addr.takeError(); |
1160 | |
1161 | addr_t load_addr = *maybe_load_addr; |
1162 | |
1163 | if (load_addr == LLDB_INVALID_ADDRESS && so_addr.IsSectionOffset()) { |
1164 | uint8_t addr_bytes[8]; |
1165 | Status error; |
1166 | |
1167 | if (target && |
1168 | target->ReadMemory(addr: so_addr, dst: &addr_bytes, dst_len: size, error, |
1169 | /*force_live_memory=*/false) == size) { |
1170 | ObjectFile *objfile = module_sp->GetObjectFile(); |
1171 | |
1172 | stack.back().GetScalar() = DerefSizeExtractDataHelper( |
1173 | addr_bytes, size_addr_bytes: size, byte_order: objfile->GetByteOrder(), size); |
1174 | stack.back().ClearContext(); |
1175 | break; |
1176 | } else { |
1177 | return llvm::createStringError( |
1178 | Fmt: "Failed to dereference pointer for DW_OP_deref_size: " |
1179 | "%s\n", |
1180 | Vals: error.AsCString()); |
1181 | } |
1182 | } |
1183 | stack.back().GetScalar() = load_addr; |
1184 | // Fall through to load address promotion code below. |
1185 | } |
1186 | |
1187 | [[fallthrough]]; |
1188 | case Value::ValueType::Scalar: |
1189 | case Value::ValueType::LoadAddress: |
1190 | if (exe_ctx) { |
1191 | if (process) { |
1192 | lldb::addr_t pointer_addr = |
1193 | stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS); |
1194 | uint8_t addr_bytes[sizeof(lldb::addr_t)]; |
1195 | Status error; |
1196 | if (process->ReadMemory(vm_addr: pointer_addr, buf: &addr_bytes, size, error) == |
1197 | size) { |
1198 | |
1199 | stack.back().GetScalar() = |
1200 | DerefSizeExtractDataHelper(addr_bytes, size_addr_bytes: sizeof(addr_bytes), |
1201 | byte_order: process->GetByteOrder(), size); |
1202 | stack.back().ClearContext(); |
1203 | } else { |
1204 | return llvm::createStringError( |
1205 | Fmt: "Failed to dereference pointer from 0x%"PRIx64 |
1206 | " for DW_OP_deref: %s\n", |
1207 | Vals: pointer_addr, Vals: error.AsCString()); |
1208 | } |
1209 | } else { |
1210 | |
1211 | return llvm::createStringError(Fmt: "NULL process for DW_OP_deref_size"); |
1212 | } |
1213 | } else { |
1214 | return llvm::createStringError( |
1215 | Fmt: "NULL execution context for DW_OP_deref_size"); |
1216 | } |
1217 | break; |
1218 | |
1219 | case Value::ValueType::Invalid: |
1220 | |
1221 | return llvm::createStringError(Fmt: "invalid value for DW_OP_deref_size"); |
1222 | } |
1223 | |
1224 | } break; |
1225 | |
1226 | // OPCODE: DW_OP_xderef_size |
1227 | // OPERANDS: 1 |
1228 | // 1 - uint8_t that specifies the size of the data to dereference. |
1229 | // DESCRIPTION: Behaves like the DW_OP_xderef operation: the entry at |
1230 | // the top of the stack is treated as an address. The second stack entry is |
1231 | // treated as an "address space identifier" for those architectures that |
1232 | // support multiple address spaces. The top two stack elements are popped, |
1233 | // a data item is retrieved through an implementation-defined address |
1234 | // calculation and pushed as the new stack top. In the DW_OP_xderef_size |
1235 | // operation, however, the size in bytes of the data retrieved from the |
1236 | // dereferenced address is specified by the single operand. This operand is |
1237 | // a 1-byte unsigned integral constant whose value may not be larger than |
1238 | // the size of an address on the target machine. The data retrieved is zero |
1239 | // extended to the size of an address on the target machine before being |
1240 | // pushed on the expression stack. |
1241 | case DW_OP_xderef_size: |
1242 | return llvm::createStringError(Fmt: "unimplemented opcode: DW_OP_xderef_size"); |
1243 | // OPCODE: DW_OP_xderef |
1244 | // OPERANDS: none |
1245 | // DESCRIPTION: Provides an extended dereference mechanism. The entry at |
1246 | // the top of the stack is treated as an address. The second stack entry is |
1247 | // treated as an "address space identifier" for those architectures that |
1248 | // support multiple address spaces. The top two stack elements are popped, |
1249 | // a data item is retrieved through an implementation-defined address |
1250 | // calculation and pushed as the new stack top. The size of the data |
1251 | // retrieved from the dereferenced address is the size of an address on the |
1252 | // target machine. |
1253 | case DW_OP_xderef: |
1254 | return llvm::createStringError(Fmt: "unimplemented opcode: DW_OP_xderef"); |
1255 | |
1256 | // All DW_OP_constXXX opcodes have a single operand as noted below: |
1257 | // |
1258 | // Opcode Operand 1 |
1259 | // DW_OP_const1u 1-byte unsigned integer constant |
1260 | // DW_OP_const1s 1-byte signed integer constant |
1261 | // DW_OP_const2u 2-byte unsigned integer constant |
1262 | // DW_OP_const2s 2-byte signed integer constant |
1263 | // DW_OP_const4u 4-byte unsigned integer constant |
1264 | // DW_OP_const4s 4-byte signed integer constant |
1265 | // DW_OP_const8u 8-byte unsigned integer constant |
1266 | // DW_OP_const8s 8-byte signed integer constant |
1267 | // DW_OP_constu unsigned LEB128 integer constant |
1268 | // DW_OP_consts signed LEB128 integer constant |
1269 | case DW_OP_const1u: |
1270 | stack.push_back(x: to_generic(opcodes.GetU8(offset_ptr: &offset))); |
1271 | break; |
1272 | case DW_OP_const1s: |
1273 | stack.push_back(x: to_generic((int8_t)opcodes.GetU8(offset_ptr: &offset))); |
1274 | break; |
1275 | case DW_OP_const2u: |
1276 | stack.push_back(x: to_generic(opcodes.GetU16(offset_ptr: &offset))); |
1277 | break; |
1278 | case DW_OP_const2s: |
1279 | stack.push_back(x: to_generic((int16_t)opcodes.GetU16(offset_ptr: &offset))); |
1280 | break; |
1281 | case DW_OP_const4u: |
1282 | stack.push_back(x: to_generic(opcodes.GetU32(offset_ptr: &offset))); |
1283 | break; |
1284 | case DW_OP_const4s: |
1285 | stack.push_back(x: to_generic((int32_t)opcodes.GetU32(offset_ptr: &offset))); |
1286 | break; |
1287 | case DW_OP_const8u: |
1288 | stack.push_back(x: to_generic(opcodes.GetU64(offset_ptr: &offset))); |
1289 | break; |
1290 | case DW_OP_const8s: |
1291 | stack.push_back(x: to_generic((int64_t)opcodes.GetU64(offset_ptr: &offset))); |
1292 | break; |
1293 | // These should also use to_generic, but we can't do that due to a |
1294 | // producer-side bug in llvm. See llvm.org/pr48087. |
1295 | case DW_OP_constu: |
1296 | stack.push_back(x: Scalar(opcodes.GetULEB128(offset_ptr: &offset))); |
1297 | break; |
1298 | case DW_OP_consts: |
1299 | stack.push_back(x: Scalar(opcodes.GetSLEB128(offset_ptr: &offset))); |
1300 | break; |
1301 | |
1302 | // OPCODE: DW_OP_dup |
1303 | // OPERANDS: none |
1304 | // DESCRIPTION: duplicates the value at the top of the stack |
1305 | case DW_OP_dup: |
1306 | if (stack.empty()) { |
1307 | return llvm::createStringError(Fmt: "expression stack empty for DW_OP_dup"); |
1308 | } else |
1309 | stack.push_back(x: stack.back()); |
1310 | break; |
1311 | |
1312 | // OPCODE: DW_OP_drop |
1313 | // OPERANDS: none |
1314 | // DESCRIPTION: pops the value at the top of the stack |
1315 | case DW_OP_drop: |
1316 | if (stack.empty()) { |
1317 | return llvm::createStringError(Fmt: "expression stack empty for DW_OP_drop"); |
1318 | } else |
1319 | stack.pop_back(); |
1320 | break; |
1321 | |
1322 | // OPCODE: DW_OP_over |
1323 | // OPERANDS: none |
1324 | // DESCRIPTION: Duplicates the entry currently second in the stack at |
1325 | // the top of the stack. |
1326 | case DW_OP_over: |
1327 | stack.push_back(x: stack[stack.size() - 2]); |
1328 | break; |
1329 | |
1330 | // OPCODE: DW_OP_pick |
1331 | // OPERANDS: uint8_t index into the current stack |
1332 | // DESCRIPTION: The stack entry with the specified index (0 through 255, |
1333 | // inclusive) is pushed on the stack |
1334 | case DW_OP_pick: { |
1335 | uint8_t pick_idx = opcodes.GetU8(offset_ptr: &offset); |
1336 | if (pick_idx < stack.size()) |
1337 | stack.push_back(x: stack[stack.size() - 1 - pick_idx]); |
1338 | else { |
1339 | return llvm::createStringError( |
1340 | Fmt: "Index %u out of range for DW_OP_pick.\n", Vals: pick_idx); |
1341 | } |
1342 | } break; |
1343 | |
1344 | // OPCODE: DW_OP_swap |
1345 | // OPERANDS: none |
1346 | // DESCRIPTION: swaps the top two stack entries. The entry at the top |
1347 | // of the stack becomes the second stack entry, and the second entry |
1348 | // becomes the top of the stack |
1349 | case DW_OP_swap: |
1350 | tmp = stack.back(); |
1351 | stack.back() = stack[stack.size() - 2]; |
1352 | stack[stack.size() - 2] = tmp; |
1353 | break; |
1354 | |
1355 | // OPCODE: DW_OP_rot |
1356 | // OPERANDS: none |
1357 | // DESCRIPTION: Rotates the first three stack entries. The entry at |
1358 | // the top of the stack becomes the third stack entry, the second entry |
1359 | // becomes the top of the stack, and the third entry becomes the second |
1360 | // entry. |
1361 | case DW_OP_rot: { |
1362 | size_t last_idx = stack.size() - 1; |
1363 | Value old_top = stack[last_idx]; |
1364 | stack[last_idx] = stack[last_idx - 1]; |
1365 | stack[last_idx - 1] = stack[last_idx - 2]; |
1366 | stack[last_idx - 2] = old_top; |
1367 | } break; |
1368 | |
1369 | // OPCODE: DW_OP_abs |
1370 | // OPERANDS: none |
1371 | // DESCRIPTION: pops the top stack entry, interprets it as a signed |
1372 | // value and pushes its absolute value. If the absolute value can not be |
1373 | // represented, the result is undefined. |
1374 | case DW_OP_abs: |
1375 | if (!stack.back().ResolveValue(exe_ctx).AbsoluteValue()) { |
1376 | return llvm::createStringError( |
1377 | Fmt: "failed to take the absolute value of the first stack item"); |
1378 | } |
1379 | break; |
1380 | |
1381 | // OPCODE: DW_OP_and |
1382 | // OPERANDS: none |
1383 | // DESCRIPTION: pops the top two stack values, performs a bitwise and |
1384 | // operation on the two, and pushes the result. |
1385 | case DW_OP_and: |
1386 | tmp = stack.back(); |
1387 | stack.pop_back(); |
1388 | stack.back().ResolveValue(exe_ctx) = |
1389 | stack.back().ResolveValue(exe_ctx) & tmp.ResolveValue(exe_ctx); |
1390 | break; |
1391 | |
1392 | // OPCODE: DW_OP_div |
1393 | // OPERANDS: none |
1394 | // DESCRIPTION: pops the top two stack values, divides the former second |
1395 | // entry by the former top of the stack using signed division, and pushes |
1396 | // the result. |
1397 | case DW_OP_div: { |
1398 | tmp = stack.back(); |
1399 | if (tmp.ResolveValue(exe_ctx).IsZero()) |
1400 | return llvm::createStringError(Fmt: "divide by zero"); |
1401 | |
1402 | stack.pop_back(); |
1403 | Scalar divisor, dividend; |
1404 | divisor = tmp.ResolveValue(exe_ctx); |
1405 | dividend = stack.back().ResolveValue(exe_ctx); |
1406 | divisor.MakeSigned(); |
1407 | dividend.MakeSigned(); |
1408 | stack.back() = dividend / divisor; |
1409 | |
1410 | if (!stack.back().ResolveValue(exe_ctx).IsValid()) |
1411 | return llvm::createStringError(Fmt: "divide failed"); |
1412 | } break; |
1413 | |
1414 | // OPCODE: DW_OP_minus |
1415 | // OPERANDS: none |
1416 | // DESCRIPTION: pops the top two stack values, subtracts the former top |
1417 | // of the stack from the former second entry, and pushes the result. |
1418 | case DW_OP_minus: |
1419 | tmp = stack.back(); |
1420 | stack.pop_back(); |
1421 | stack.back().ResolveValue(exe_ctx) = |
1422 | stack.back().ResolveValue(exe_ctx) - tmp.ResolveValue(exe_ctx); |
1423 | break; |
1424 | |
1425 | // OPCODE: DW_OP_mod |
1426 | // OPERANDS: none |
1427 | // DESCRIPTION: pops the top two stack values and pushes the result of |
1428 | // the calculation: former second stack entry modulo the former top of the |
1429 | // stack. |
1430 | case DW_OP_mod: |
1431 | tmp = stack.back(); |
1432 | stack.pop_back(); |
1433 | stack.back().ResolveValue(exe_ctx) = |
1434 | stack.back().ResolveValue(exe_ctx) % tmp.ResolveValue(exe_ctx); |
1435 | break; |
1436 | |
1437 | // OPCODE: DW_OP_mul |
1438 | // OPERANDS: none |
1439 | // DESCRIPTION: pops the top two stack entries, multiplies them |
1440 | // together, and pushes the result. |
1441 | case DW_OP_mul: |
1442 | tmp = stack.back(); |
1443 | stack.pop_back(); |
1444 | stack.back().ResolveValue(exe_ctx) = |
1445 | stack.back().ResolveValue(exe_ctx) * tmp.ResolveValue(exe_ctx); |
1446 | break; |
1447 | |
1448 | // OPCODE: DW_OP_neg |
1449 | // OPERANDS: none |
1450 | // DESCRIPTION: pops the top stack entry, and pushes its negation. |
1451 | case DW_OP_neg: |
1452 | if (!stack.back().ResolveValue(exe_ctx).UnaryNegate()) |
1453 | return llvm::createStringError(Fmt: "unary negate failed"); |
1454 | break; |
1455 | |
1456 | // OPCODE: DW_OP_not |
1457 | // OPERANDS: none |
1458 | // DESCRIPTION: pops the top stack entry, and pushes its bitwise |
1459 | // complement |
1460 | case DW_OP_not: |
1461 | if (!stack.back().ResolveValue(exe_ctx).OnesComplement()) |
1462 | return llvm::createStringError(Fmt: "logical NOT failed"); |
1463 | break; |
1464 | |
1465 | // OPCODE: DW_OP_or |
1466 | // OPERANDS: none |
1467 | // DESCRIPTION: pops the top two stack entries, performs a bitwise or |
1468 | // operation on the two, and pushes the result. |
1469 | case DW_OP_or: |
1470 | tmp = stack.back(); |
1471 | stack.pop_back(); |
1472 | stack.back().ResolveValue(exe_ctx) = |
1473 | stack.back().ResolveValue(exe_ctx) | tmp.ResolveValue(exe_ctx); |
1474 | break; |
1475 | |
1476 | // OPCODE: DW_OP_plus |
1477 | // OPERANDS: none |
1478 | // DESCRIPTION: pops the top two stack entries, adds them together, and |
1479 | // pushes the result. |
1480 | case DW_OP_plus: |
1481 | tmp = stack.back(); |
1482 | stack.pop_back(); |
1483 | stack.back().GetScalar() += tmp.GetScalar(); |
1484 | break; |
1485 | |
1486 | // OPCODE: DW_OP_plus_uconst |
1487 | // OPERANDS: none |
1488 | // DESCRIPTION: pops the top stack entry, adds it to the unsigned LEB128 |
1489 | // constant operand and pushes the result. |
1490 | case DW_OP_plus_uconst: { |
1491 | const uint64_t uconst_value = opcodes.GetULEB128(offset_ptr: &offset); |
1492 | // Implicit conversion from a UINT to a Scalar... |
1493 | stack.back().GetScalar() += uconst_value; |
1494 | if (!stack.back().GetScalar().IsValid()) |
1495 | return llvm::createStringError(Fmt: "DW_OP_plus_uconst failed"); |
1496 | } break; |
1497 | |
1498 | // OPCODE: DW_OP_shl |
1499 | // OPERANDS: none |
1500 | // DESCRIPTION: pops the top two stack entries, shifts the former |
1501 | // second entry left by the number of bits specified by the former top of |
1502 | // the stack, and pushes the result. |
1503 | case DW_OP_shl: |
1504 | tmp = stack.back(); |
1505 | stack.pop_back(); |
1506 | stack.back().ResolveValue(exe_ctx) <<= tmp.ResolveValue(exe_ctx); |
1507 | break; |
1508 | |
1509 | // OPCODE: DW_OP_shr |
1510 | // OPERANDS: none |
1511 | // DESCRIPTION: pops the top two stack entries, shifts the former second |
1512 | // entry right logically (filling with zero bits) by the number of bits |
1513 | // specified by the former top of the stack, and pushes the result. |
1514 | case DW_OP_shr: |
1515 | tmp = stack.back(); |
1516 | stack.pop_back(); |
1517 | if (!stack.back().ResolveValue(exe_ctx).ShiftRightLogical( |
1518 | rhs: tmp.ResolveValue(exe_ctx))) |
1519 | return llvm::createStringError(Fmt: "DW_OP_shr failed"); |
1520 | break; |
1521 | |
1522 | // OPCODE: DW_OP_shra |
1523 | // OPERANDS: none |
1524 | // DESCRIPTION: pops the top two stack entries, shifts the former second |
1525 | // entry right arithmetically (divide the magnitude by 2, keep the same |
1526 | // sign for the result) by the number of bits specified by the former top |
1527 | // of the stack, and pushes the result. |
1528 | case DW_OP_shra: |
1529 | tmp = stack.back(); |
1530 | stack.pop_back(); |
1531 | stack.back().ResolveValue(exe_ctx) >>= tmp.ResolveValue(exe_ctx); |
1532 | break; |
1533 | |
1534 | // OPCODE: DW_OP_xor |
1535 | // OPERANDS: none |
1536 | // DESCRIPTION: pops the top two stack entries, performs the bitwise |
1537 | // exclusive-or operation on the two, and pushes the result. |
1538 | case DW_OP_xor: |
1539 | tmp = stack.back(); |
1540 | stack.pop_back(); |
1541 | stack.back().ResolveValue(exe_ctx) = |
1542 | stack.back().ResolveValue(exe_ctx) ^ tmp.ResolveValue(exe_ctx); |
1543 | break; |
1544 | |
1545 | // OPCODE: DW_OP_skip |
1546 | // OPERANDS: int16_t |
1547 | // DESCRIPTION: An unconditional branch. Its single operand is a 2-byte |
1548 | // signed integer constant. The 2-byte constant is the number of bytes of |
1549 | // the DWARF expression to skip forward or backward from the current |
1550 | // operation, beginning after the 2-byte constant. |
1551 | case DW_OP_skip: { |
1552 | int16_t skip_offset = (int16_t)opcodes.GetU16(offset_ptr: &offset); |
1553 | lldb::offset_t new_offset = offset + skip_offset; |
1554 | // New offset can point at the end of the data, in this case we should |
1555 | // terminate the DWARF expression evaluation (will happen in the loop |
1556 | // condition). |
1557 | if (new_offset <= opcodes.GetByteSize()) |
1558 | offset = new_offset; |
1559 | else { |
1560 | return llvm::createStringError(S: llvm::formatv( |
1561 | Fmt: "Invalid opcode offset in DW_OP_skip: {0}+({1}) > {2}", Vals&: offset, |
1562 | Vals&: skip_offset, Vals: opcodes.GetByteSize())); |
1563 | } |
1564 | } break; |
1565 | |
1566 | // OPCODE: DW_OP_bra |
1567 | // OPERANDS: int16_t |
1568 | // DESCRIPTION: A conditional branch. Its single operand is a 2-byte |
1569 | // signed integer constant. This operation pops the top of stack. If the |
1570 | // value popped is not the constant 0, the 2-byte constant operand is the |
1571 | // number of bytes of the DWARF expression to skip forward or backward from |
1572 | // the current operation, beginning after the 2-byte constant. |
1573 | case DW_OP_bra: { |
1574 | tmp = stack.back(); |
1575 | stack.pop_back(); |
1576 | int16_t bra_offset = (int16_t)opcodes.GetU16(offset_ptr: &offset); |
1577 | Scalar zero(0); |
1578 | if (tmp.ResolveValue(exe_ctx) != zero) { |
1579 | lldb::offset_t new_offset = offset + bra_offset; |
1580 | // New offset can point at the end of the data, in this case we should |
1581 | // terminate the DWARF expression evaluation (will happen in the loop |
1582 | // condition). |
1583 | if (new_offset <= opcodes.GetByteSize()) |
1584 | offset = new_offset; |
1585 | else { |
1586 | return llvm::createStringError(S: llvm::formatv( |
1587 | Fmt: "Invalid opcode offset in DW_OP_bra: {0}+({1}) > {2}", Vals&: offset, |
1588 | Vals&: bra_offset, Vals: opcodes.GetByteSize())); |
1589 | } |
1590 | } |
1591 | } break; |
1592 | |
1593 | // OPCODE: DW_OP_eq |
1594 | // OPERANDS: none |
1595 | // DESCRIPTION: pops the top two stack values, compares using the |
1596 | // equals (==) operator. |
1597 | // STACK RESULT: push the constant value 1 onto the stack if the result |
1598 | // of the operation is true or the constant value 0 if the result of the |
1599 | // operation is false. |
1600 | case DW_OP_eq: |
1601 | tmp = stack.back(); |
1602 | stack.pop_back(); |
1603 | stack.back().ResolveValue(exe_ctx) = |
1604 | stack.back().ResolveValue(exe_ctx) == tmp.ResolveValue(exe_ctx); |
1605 | break; |
1606 | |
1607 | // OPCODE: DW_OP_ge |
1608 | // OPERANDS: none |
1609 | // DESCRIPTION: pops the top two stack values, compares using the |
1610 | // greater than or equal to (>=) operator. |
1611 | // STACK RESULT: push the constant value 1 onto the stack if the result |
1612 | // of the operation is true or the constant value 0 if the result of the |
1613 | // operation is false. |
1614 | case DW_OP_ge: |
1615 | tmp = stack.back(); |
1616 | stack.pop_back(); |
1617 | stack.back().ResolveValue(exe_ctx) = |
1618 | stack.back().ResolveValue(exe_ctx) >= tmp.ResolveValue(exe_ctx); |
1619 | break; |
1620 | |
1621 | // OPCODE: DW_OP_gt |
1622 | // OPERANDS: none |
1623 | // DESCRIPTION: pops the top two stack values, compares using the |
1624 | // greater than (>) operator. |
1625 | // STACK RESULT: push the constant value 1 onto the stack if the result |
1626 | // of the operation is true or the constant value 0 if the result of the |
1627 | // operation is false. |
1628 | case DW_OP_gt: |
1629 | tmp = stack.back(); |
1630 | stack.pop_back(); |
1631 | stack.back().ResolveValue(exe_ctx) = |
1632 | stack.back().ResolveValue(exe_ctx) > tmp.ResolveValue(exe_ctx); |
1633 | break; |
1634 | |
1635 | // OPCODE: DW_OP_le |
1636 | // OPERANDS: none |
1637 | // DESCRIPTION: pops the top two stack values, compares using the |
1638 | // less than or equal to (<=) operator. |
1639 | // STACK RESULT: push the constant value 1 onto the stack if the result |
1640 | // of the operation is true or the constant value 0 if the result of the |
1641 | // operation is false. |
1642 | case DW_OP_le: |
1643 | tmp = stack.back(); |
1644 | stack.pop_back(); |
1645 | stack.back().ResolveValue(exe_ctx) = |
1646 | stack.back().ResolveValue(exe_ctx) <= tmp.ResolveValue(exe_ctx); |
1647 | break; |
1648 | |
1649 | // OPCODE: DW_OP_lt |
1650 | // OPERANDS: none |
1651 | // DESCRIPTION: pops the top two stack values, compares using the |
1652 | // less than (<) operator. |
1653 | // STACK RESULT: push the constant value 1 onto the stack if the result |
1654 | // of the operation is true or the constant value 0 if the result of the |
1655 | // operation is false. |
1656 | case DW_OP_lt: |
1657 | tmp = stack.back(); |
1658 | stack.pop_back(); |
1659 | stack.back().ResolveValue(exe_ctx) = |
1660 | stack.back().ResolveValue(exe_ctx) < tmp.ResolveValue(exe_ctx); |
1661 | break; |
1662 | |
1663 | // OPCODE: DW_OP_ne |
1664 | // OPERANDS: none |
1665 | // DESCRIPTION: pops the top two stack values, compares using the |
1666 | // not equal (!=) operator. |
1667 | // STACK RESULT: push the constant value 1 onto the stack if the result |
1668 | // of the operation is true or the constant value 0 if the result of the |
1669 | // operation is false. |
1670 | case DW_OP_ne: |
1671 | tmp = stack.back(); |
1672 | stack.pop_back(); |
1673 | stack.back().ResolveValue(exe_ctx) = |
1674 | stack.back().ResolveValue(exe_ctx) != tmp.ResolveValue(exe_ctx); |
1675 | break; |
1676 | |
1677 | // OPCODE: DW_OP_litn |
1678 | // OPERANDS: none |
1679 | // DESCRIPTION: encode the unsigned literal values from 0 through 31. |
1680 | // STACK RESULT: push the unsigned literal constant value onto the top |
1681 | // of the stack. |
1682 | case DW_OP_lit0: |
1683 | case DW_OP_lit1: |
1684 | case DW_OP_lit2: |
1685 | case DW_OP_lit3: |
1686 | case DW_OP_lit4: |
1687 | case DW_OP_lit5: |
1688 | case DW_OP_lit6: |
1689 | case DW_OP_lit7: |
1690 | case DW_OP_lit8: |
1691 | case DW_OP_lit9: |
1692 | case DW_OP_lit10: |
1693 | case DW_OP_lit11: |
1694 | case DW_OP_lit12: |
1695 | case DW_OP_lit13: |
1696 | case DW_OP_lit14: |
1697 | case DW_OP_lit15: |
1698 | case DW_OP_lit16: |
1699 | case DW_OP_lit17: |
1700 | case DW_OP_lit18: |
1701 | case DW_OP_lit19: |
1702 | case DW_OP_lit20: |
1703 | case DW_OP_lit21: |
1704 | case DW_OP_lit22: |
1705 | case DW_OP_lit23: |
1706 | case DW_OP_lit24: |
1707 | case DW_OP_lit25: |
1708 | case DW_OP_lit26: |
1709 | case DW_OP_lit27: |
1710 | case DW_OP_lit28: |
1711 | case DW_OP_lit29: |
1712 | case DW_OP_lit30: |
1713 | case DW_OP_lit31: |
1714 | stack.push_back(x: to_generic(op - DW_OP_lit0)); |
1715 | break; |
1716 | |
1717 | // OPCODE: DW_OP_regN |
1718 | // OPERANDS: none |
1719 | // DESCRIPTION: Push the value in register n on the top of the stack. |
1720 | case DW_OP_reg0: |
1721 | case DW_OP_reg1: |
1722 | case DW_OP_reg2: |
1723 | case DW_OP_reg3: |
1724 | case DW_OP_reg4: |
1725 | case DW_OP_reg5: |
1726 | case DW_OP_reg6: |
1727 | case DW_OP_reg7: |
1728 | case DW_OP_reg8: |
1729 | case DW_OP_reg9: |
1730 | case DW_OP_reg10: |
1731 | case DW_OP_reg11: |
1732 | case DW_OP_reg12: |
1733 | case DW_OP_reg13: |
1734 | case DW_OP_reg14: |
1735 | case DW_OP_reg15: |
1736 | case DW_OP_reg16: |
1737 | case DW_OP_reg17: |
1738 | case DW_OP_reg18: |
1739 | case DW_OP_reg19: |
1740 | case DW_OP_reg20: |
1741 | case DW_OP_reg21: |
1742 | case DW_OP_reg22: |
1743 | case DW_OP_reg23: |
1744 | case DW_OP_reg24: |
1745 | case DW_OP_reg25: |
1746 | case DW_OP_reg26: |
1747 | case DW_OP_reg27: |
1748 | case DW_OP_reg28: |
1749 | case DW_OP_reg29: |
1750 | case DW_OP_reg30: |
1751 | case DW_OP_reg31: { |
1752 | dwarf4_location_description_kind = Register; |
1753 | reg_num = op - DW_OP_reg0; |
1754 | |
1755 | if (llvm::Error err = |
1756 | ReadRegisterValueAsScalar(reg_ctx, reg_kind, reg_num, value&: tmp)) |
1757 | return err; |
1758 | stack.push_back(x: tmp); |
1759 | } break; |
1760 | // OPCODE: DW_OP_regx |
1761 | // OPERANDS: |
1762 | // ULEB128 literal operand that encodes the register. |
1763 | // DESCRIPTION: Push the value in register on the top of the stack. |
1764 | case DW_OP_regx: { |
1765 | dwarf4_location_description_kind = Register; |
1766 | reg_num = opcodes.GetULEB128(offset_ptr: &offset); |
1767 | Status read_err; |
1768 | if (llvm::Error err = |
1769 | ReadRegisterValueAsScalar(reg_ctx, reg_kind, reg_num, value&: tmp)) |
1770 | return err; |
1771 | stack.push_back(x: tmp); |
1772 | } break; |
1773 | |
1774 | // OPCODE: DW_OP_bregN |
1775 | // OPERANDS: |
1776 | // SLEB128 offset from register N |
1777 | // DESCRIPTION: Value is in memory at the address specified by register |
1778 | // N plus an offset. |
1779 | case DW_OP_breg0: |
1780 | case DW_OP_breg1: |
1781 | case DW_OP_breg2: |
1782 | case DW_OP_breg3: |
1783 | case DW_OP_breg4: |
1784 | case DW_OP_breg5: |
1785 | case DW_OP_breg6: |
1786 | case DW_OP_breg7: |
1787 | case DW_OP_breg8: |
1788 | case DW_OP_breg9: |
1789 | case DW_OP_breg10: |
1790 | case DW_OP_breg11: |
1791 | case DW_OP_breg12: |
1792 | case DW_OP_breg13: |
1793 | case DW_OP_breg14: |
1794 | case DW_OP_breg15: |
1795 | case DW_OP_breg16: |
1796 | case DW_OP_breg17: |
1797 | case DW_OP_breg18: |
1798 | case DW_OP_breg19: |
1799 | case DW_OP_breg20: |
1800 | case DW_OP_breg21: |
1801 | case DW_OP_breg22: |
1802 | case DW_OP_breg23: |
1803 | case DW_OP_breg24: |
1804 | case DW_OP_breg25: |
1805 | case DW_OP_breg26: |
1806 | case DW_OP_breg27: |
1807 | case DW_OP_breg28: |
1808 | case DW_OP_breg29: |
1809 | case DW_OP_breg30: |
1810 | case DW_OP_breg31: { |
1811 | reg_num = op - DW_OP_breg0; |
1812 | if (llvm::Error err = |
1813 | ReadRegisterValueAsScalar(reg_ctx, reg_kind, reg_num, value&: tmp)) |
1814 | return err; |
1815 | |
1816 | int64_t breg_offset = opcodes.GetSLEB128(offset_ptr: &offset); |
1817 | tmp.ResolveValue(exe_ctx) += (uint64_t)breg_offset; |
1818 | tmp.ClearContext(); |
1819 | stack.push_back(x: tmp); |
1820 | stack.back().SetValueType(Value::ValueType::LoadAddress); |
1821 | } break; |
1822 | // OPCODE: DW_OP_bregx |
1823 | // OPERANDS: 2 |
1824 | // ULEB128 literal operand that encodes the register. |
1825 | // SLEB128 offset from register N |
1826 | // DESCRIPTION: Value is in memory at the address specified by register |
1827 | // N plus an offset. |
1828 | case DW_OP_bregx: { |
1829 | reg_num = opcodes.GetULEB128(offset_ptr: &offset); |
1830 | if (llvm::Error err = |
1831 | ReadRegisterValueAsScalar(reg_ctx, reg_kind, reg_num, value&: tmp)) |
1832 | return err; |
1833 | |
1834 | int64_t breg_offset = opcodes.GetSLEB128(offset_ptr: &offset); |
1835 | tmp.ResolveValue(exe_ctx) += (uint64_t)breg_offset; |
1836 | tmp.ClearContext(); |
1837 | stack.push_back(x: tmp); |
1838 | stack.back().SetValueType(Value::ValueType::LoadAddress); |
1839 | } break; |
1840 | |
1841 | case DW_OP_fbreg: |
1842 | if (exe_ctx) { |
1843 | if (frame) { |
1844 | Scalar value; |
1845 | if (llvm::Error err = frame->GetFrameBaseValue(value)) |
1846 | return err; |
1847 | int64_t fbreg_offset = opcodes.GetSLEB128(offset_ptr: &offset); |
1848 | value += fbreg_offset; |
1849 | stack.push_back(x: value); |
1850 | stack.back().SetValueType(Value::ValueType::LoadAddress); |
1851 | } else { |
1852 | return llvm::createStringError( |
1853 | Fmt: "invalid stack frame in context for DW_OP_fbreg opcode"); |
1854 | } |
1855 | } else { |
1856 | return llvm::createStringError( |
1857 | Fmt: "NULL execution context for DW_OP_fbreg"); |
1858 | } |
1859 | |
1860 | break; |
1861 | |
1862 | // OPCODE: DW_OP_nop |
1863 | // OPERANDS: none |
1864 | // DESCRIPTION: A place holder. It has no effect on the location stack |
1865 | // or any of its values. |
1866 | case DW_OP_nop: |
1867 | break; |
1868 | |
1869 | // OPCODE: DW_OP_piece |
1870 | // OPERANDS: 1 |
1871 | // ULEB128: byte size of the piece |
1872 | // DESCRIPTION: The operand describes the size in bytes of the piece of |
1873 | // the object referenced by the DWARF expression whose result is at the top |
1874 | // of the stack. If the piece is located in a register, but does not occupy |
1875 | // the entire register, the placement of the piece within that register is |
1876 | // defined by the ABI. |
1877 | // |
1878 | // Many compilers store a single variable in sets of registers, or store a |
1879 | // variable partially in memory and partially in registers. DW_OP_piece |
1880 | // provides a way of describing how large a part of a variable a particular |
1881 | // DWARF expression refers to. |
1882 | case DW_OP_piece: { |
1883 | LocationDescriptionKind piece_locdesc = dwarf4_location_description_kind; |
1884 | // Reset for the next piece. |
1885 | dwarf4_location_description_kind = Memory; |
1886 | |
1887 | const uint64_t piece_byte_size = opcodes.GetULEB128(offset_ptr: &offset); |
1888 | |
1889 | if (piece_byte_size > 0) { |
1890 | Value curr_piece; |
1891 | |
1892 | if (stack.empty()) { |
1893 | UpdateValueTypeFromLocationDescription( |
1894 | log, dwarf_cu, kind: LocationDescriptionKind::Empty); |
1895 | // In a multi-piece expression, this means that the current piece is |
1896 | // not available. Fill with zeros for now by resizing the data and |
1897 | // appending it |
1898 | curr_piece.ResizeData(len: piece_byte_size); |
1899 | // Note that "0" is not a correct value for the unknown bits. |
1900 | // It would be better to also return a mask of valid bits together |
1901 | // with the expression result, so the debugger can print missing |
1902 | // members as "<optimized out>" or something. |
1903 | ::memset(s: curr_piece.GetBuffer().GetBytes(), c: 0, n: piece_byte_size); |
1904 | pieces.AppendDataToHostBuffer(rhs: curr_piece); |
1905 | } else { |
1906 | Status error; |
1907 | // Extract the current piece into "curr_piece" |
1908 | Value curr_piece_source_value(stack.back()); |
1909 | stack.pop_back(); |
1910 | UpdateValueTypeFromLocationDescription(log, dwarf_cu, kind: piece_locdesc, |
1911 | value: &curr_piece_source_value); |
1912 | |
1913 | const Value::ValueType curr_piece_source_value_type = |
1914 | curr_piece_source_value.GetValueType(); |
1915 | Scalar &scalar = curr_piece_source_value.GetScalar(); |
1916 | lldb::addr_t addr = scalar.ULongLong(LLDB_INVALID_ADDRESS); |
1917 | switch (curr_piece_source_value_type) { |
1918 | case Value::ValueType::Invalid: |
1919 | return llvm::createStringError(Fmt: "invalid value type"); |
1920 | case Value::ValueType::FileAddress: |
1921 | if (target) { |
1922 | curr_piece_source_value.ConvertToLoadAddress(module: module_sp.get(), |
1923 | target); |
1924 | addr = scalar.ULongLong(LLDB_INVALID_ADDRESS); |
1925 | } else { |
1926 | return llvm::createStringError( |
1927 | Fmt: "unable to convert file address 0x%"PRIx64 |
1928 | " to load address " |
1929 | "for DW_OP_piece(%"PRIu64 "): " |
1930 | "no target available", |
1931 | Vals: addr, Vals: piece_byte_size); |
1932 | } |
1933 | [[fallthrough]]; |
1934 | case Value::ValueType::LoadAddress: { |
1935 | if (target) { |
1936 | if (curr_piece.ResizeData(len: piece_byte_size) == piece_byte_size) { |
1937 | if (target->ReadMemory(addr, dst: curr_piece.GetBuffer().GetBytes(), |
1938 | dst_len: piece_byte_size, error, |
1939 | /*force_live_memory=*/false) != |
1940 | piece_byte_size) { |
1941 | const char *addr_type = (curr_piece_source_value_type == |
1942 | Value::ValueType::LoadAddress) |
1943 | ? "load" |
1944 | : "file"; |
1945 | return llvm::createStringError( |
1946 | Fmt: "failed to read memory DW_OP_piece(%"PRIu64 |
1947 | ") from %s address 0x%"PRIx64, |
1948 | Vals: piece_byte_size, Vals: addr_type, Vals: addr); |
1949 | } |
1950 | } else { |
1951 | return llvm::createStringError( |
1952 | Fmt: "failed to resize the piece memory buffer for " |
1953 | "DW_OP_piece(%"PRIu64 ")", |
1954 | Vals: piece_byte_size); |
1955 | } |
1956 | } |
1957 | } break; |
1958 | case Value::ValueType::HostAddress: { |
1959 | return llvm::createStringError( |
1960 | Fmt: "failed to read memory DW_OP_piece(%"PRIu64 |
1961 | ") from host address 0x%"PRIx64, |
1962 | Vals: piece_byte_size, Vals: addr); |
1963 | } break; |
1964 | |
1965 | case Value::ValueType::Scalar: { |
1966 | uint32_t bit_size = piece_byte_size * 8; |
1967 | uint32_t bit_offset = 0; |
1968 | if (!scalar.ExtractBitfield( |
1969 | bit_size, bit_offset)) { |
1970 | return llvm::createStringError( |
1971 | Fmt: "unable to extract %"PRIu64 " bytes from a %"PRIu64 |
1972 | " byte scalar value.", |
1973 | Vals: piece_byte_size, |
1974 | Vals: (uint64_t)curr_piece_source_value.GetScalar().GetByteSize()); |
1975 | } |
1976 | // Create curr_piece with bit_size. By default Scalar |
1977 | // grows to the nearest host integer type. |
1978 | llvm::APInt fail_value(1, 0, false); |
1979 | llvm::APInt ap_int = scalar.UInt128(fail_value); |
1980 | assert(ap_int.getBitWidth() >= bit_size); |
1981 | llvm::ArrayRef<uint64_t> buf{ap_int.getRawData(), |
1982 | ap_int.getNumWords()}; |
1983 | curr_piece.GetScalar() = Scalar(llvm::APInt(bit_size, buf)); |
1984 | } break; |
1985 | } |
1986 | |
1987 | // Check if this is the first piece? |
1988 | if (op_piece_offset == 0) { |
1989 | // This is the first piece, we should push it back onto the stack |
1990 | // so subsequent pieces will be able to access this piece and add |
1991 | // to it. |
1992 | if (pieces.AppendDataToHostBuffer(rhs: curr_piece) == 0) { |
1993 | return llvm::createStringError(Fmt: "failed to append piece data"); |
1994 | } |
1995 | } else { |
1996 | // If this is the second or later piece there should be a value on |
1997 | // the stack. |
1998 | if (pieces.GetBuffer().GetByteSize() != op_piece_offset) { |
1999 | return llvm::createStringError( |
2000 | Fmt: "DW_OP_piece for offset %"PRIu64 |
2001 | " but top of stack is of size %"PRIu64, |
2002 | Vals: op_piece_offset, Vals: pieces.GetBuffer().GetByteSize()); |
2003 | } |
2004 | |
2005 | if (pieces.AppendDataToHostBuffer(rhs: curr_piece) == 0) |
2006 | return llvm::createStringError(Fmt: "failed to append piece data"); |
2007 | } |
2008 | } |
2009 | op_piece_offset += piece_byte_size; |
2010 | } |
2011 | } break; |
2012 | |
2013 | case DW_OP_bit_piece: // 0x9d ULEB128 bit size, ULEB128 bit offset (DWARF3); |
2014 | if (stack.size() < 1) { |
2015 | UpdateValueTypeFromLocationDescription(log, dwarf_cu, |
2016 | kind: LocationDescriptionKind::Empty); |
2017 | // Reset for the next piece. |
2018 | dwarf4_location_description_kind = Memory; |
2019 | return llvm::createStringError( |
2020 | Fmt: "expression stack needs at least 1 item for DW_OP_bit_piece"); |
2021 | } else { |
2022 | UpdateValueTypeFromLocationDescription( |
2023 | log, dwarf_cu, kind: dwarf4_location_description_kind, value: &stack.back()); |
2024 | // Reset for the next piece. |
2025 | dwarf4_location_description_kind = Memory; |
2026 | const uint64_t piece_bit_size = opcodes.GetULEB128(offset_ptr: &offset); |
2027 | const uint64_t piece_bit_offset = opcodes.GetULEB128(offset_ptr: &offset); |
2028 | switch (stack.back().GetValueType()) { |
2029 | case Value::ValueType::Invalid: |
2030 | return llvm::createStringError( |
2031 | Fmt: "unable to extract bit value from invalid value"); |
2032 | case Value::ValueType::Scalar: { |
2033 | if (!stack.back().GetScalar().ExtractBitfield(bit_size: piece_bit_size, |
2034 | bit_offset: piece_bit_offset)) { |
2035 | return llvm::createStringError( |
2036 | Fmt: "unable to extract %"PRIu64 " bit value with %"PRIu64 |
2037 | " bit offset from a %"PRIu64 " bit scalar value.", |
2038 | Vals: piece_bit_size, Vals: piece_bit_offset, |
2039 | Vals: (uint64_t)(stack.back().GetScalar().GetByteSize() * 8)); |
2040 | } |
2041 | } break; |
2042 | |
2043 | case Value::ValueType::FileAddress: |
2044 | case Value::ValueType::LoadAddress: |
2045 | case Value::ValueType::HostAddress: |
2046 | return llvm::createStringError( |
2047 | Fmt: "unable to extract DW_OP_bit_piece(bit_size = %"PRIu64 |
2048 | ", bit_offset = %"PRIu64 ") from an address value.", |
2049 | Vals: piece_bit_size, Vals: piece_bit_offset); |
2050 | } |
2051 | } |
2052 | break; |
2053 | |
2054 | // OPCODE: DW_OP_implicit_value |
2055 | // OPERANDS: 2 |
2056 | // ULEB128 size of the value block in bytes |
2057 | // uint8_t* block bytes encoding value in target's memory |
2058 | // representation |
2059 | // DESCRIPTION: Value is immediately stored in block in the debug info with |
2060 | // the memory representation of the target. |
2061 | case DW_OP_implicit_value: { |
2062 | dwarf4_location_description_kind = Implicit; |
2063 | |
2064 | const uint32_t len = opcodes.GetULEB128(offset_ptr: &offset); |
2065 | const void *data = opcodes.GetData(offset_ptr: &offset, length: len); |
2066 | |
2067 | if (!data) { |
2068 | LLDB_LOG(log, "Evaluate_DW_OP_implicit_value: could not be read data"); |
2069 | return llvm::createStringError(Fmt: "could not evaluate %s", |
2070 | Vals: DW_OP_value_to_name(val: op)); |
2071 | } |
2072 | |
2073 | Value result(data, len); |
2074 | stack.push_back(x: result); |
2075 | break; |
2076 | } |
2077 | |
2078 | case DW_OP_implicit_pointer: { |
2079 | dwarf4_location_description_kind = Implicit; |
2080 | return llvm::createStringError(Fmt: "Could not evaluate %s.", |
2081 | Vals: DW_OP_value_to_name(val: op)); |
2082 | } |
2083 | |
2084 | // OPCODE: DW_OP_push_object_address |
2085 | // OPERANDS: none |
2086 | // DESCRIPTION: Pushes the address of the object currently being |
2087 | // evaluated as part of evaluation of a user presented expression. This |
2088 | // object may correspond to an independent variable described by its own |
2089 | // DIE or it may be a component of an array, structure, or class whose |
2090 | // address has been dynamically determined by an earlier step during user |
2091 | // expression evaluation. |
2092 | case DW_OP_push_object_address: |
2093 | if (object_address_ptr) |
2094 | stack.push_back(x: *object_address_ptr); |
2095 | else { |
2096 | return llvm::createStringError(Fmt: "DW_OP_push_object_address used without " |
2097 | "specifying an object address"); |
2098 | } |
2099 | break; |
2100 | |
2101 | // OPCODE: DW_OP_call2 |
2102 | // OPERANDS: |
2103 | // uint16_t compile unit relative offset of a DIE |
2104 | // DESCRIPTION: Performs subroutine calls during evaluation |
2105 | // of a DWARF expression. The operand is the 2-byte unsigned offset of a |
2106 | // debugging information entry in the current compilation unit. |
2107 | // |
2108 | // Operand interpretation is exactly like that for DW_FORM_ref2. |
2109 | // |
2110 | // This operation transfers control of DWARF expression evaluation to the |
2111 | // DW_AT_location attribute of the referenced DIE. If there is no such |
2112 | // attribute, then there is no effect. Execution of the DWARF expression of |
2113 | // a DW_AT_location attribute may add to and/or remove from values on the |
2114 | // stack. Execution returns to the point following the call when the end of |
2115 | // the attribute is reached. Values on the stack at the time of the call |
2116 | // may be used as parameters by the called expression and values left on |
2117 | // the stack by the called expression may be used as return values by prior |
2118 | // agreement between the calling and called expressions. |
2119 | case DW_OP_call2: |
2120 | return llvm::createStringError(Fmt: "unimplemented opcode DW_OP_call2"); |
2121 | // OPCODE: DW_OP_call4 |
2122 | // OPERANDS: 1 |
2123 | // uint32_t compile unit relative offset of a DIE |
2124 | // DESCRIPTION: Performs a subroutine call during evaluation of a DWARF |
2125 | // expression. For DW_OP_call4, the operand is a 4-byte unsigned offset of |
2126 | // a debugging information entry in the current compilation unit. |
2127 | // |
2128 | // Operand interpretation DW_OP_call4 is exactly like that for |
2129 | // DW_FORM_ref4. |
2130 | // |
2131 | // This operation transfers control of DWARF expression evaluation to the |
2132 | // DW_AT_location attribute of the referenced DIE. If there is no such |
2133 | // attribute, then there is no effect. Execution of the DWARF expression of |
2134 | // a DW_AT_location attribute may add to and/or remove from values on the |
2135 | // stack. Execution returns to the point following the call when the end of |
2136 | // the attribute is reached. Values on the stack at the time of the call |
2137 | // may be used as parameters by the called expression and values left on |
2138 | // the stack by the called expression may be used as return values by prior |
2139 | // agreement between the calling and called expressions. |
2140 | case DW_OP_call4: |
2141 | return llvm::createStringError(Fmt: "unimplemented opcode DW_OP_call4"); |
2142 | |
2143 | // OPCODE: DW_OP_stack_value |
2144 | // OPERANDS: None |
2145 | // DESCRIPTION: Specifies that the object does not exist in memory but |
2146 | // rather is a constant value. The value from the top of the stack is the |
2147 | // value to be used. This is the actual object value and not the location. |
2148 | case DW_OP_stack_value: |
2149 | dwarf4_location_description_kind = Implicit; |
2150 | stack.back().SetValueType(Value::ValueType::Scalar); |
2151 | break; |
2152 | |
2153 | // OPCODE: DW_OP_convert |
2154 | // OPERANDS: 1 |
2155 | // A ULEB128 that is either a DIE offset of a |
2156 | // DW_TAG_base_type or 0 for the generic (pointer-sized) type. |
2157 | // |
2158 | // DESCRIPTION: Pop the top stack element, convert it to a |
2159 | // different type, and push the result. |
2160 | case DW_OP_convert: { |
2161 | const uint64_t relative_die_offset = opcodes.GetULEB128(offset_ptr: &offset); |
2162 | uint64_t bit_size; |
2163 | bool sign; |
2164 | if (relative_die_offset == 0) { |
2165 | // The generic type has the size of an address on the target |
2166 | // machine and an unspecified signedness. Scalar has no |
2167 | // "unspecified signedness", so we use unsigned types. |
2168 | if (!module_sp) |
2169 | return llvm::createStringError(Fmt: "no module"); |
2170 | sign = false; |
2171 | bit_size = module_sp->GetArchitecture().GetAddressByteSize() * 8; |
2172 | if (!bit_size) |
2173 | return llvm::createStringError(Fmt: "unspecified architecture"); |
2174 | } else { |
2175 | auto bit_size_sign_or_err = |
2176 | dwarf_cu->GetDIEBitSizeAndSign(relative_die_offset); |
2177 | if (!bit_size_sign_or_err) |
2178 | return bit_size_sign_or_err.takeError(); |
2179 | bit_size = bit_size_sign_or_err->first; |
2180 | sign = bit_size_sign_or_err->second; |
2181 | } |
2182 | Scalar &top = stack.back().ResolveValue(exe_ctx); |
2183 | top.TruncOrExtendTo(bits: bit_size, sign); |
2184 | break; |
2185 | } |
2186 | |
2187 | // OPCODE: DW_OP_call_frame_cfa |
2188 | // OPERANDS: None |
2189 | // DESCRIPTION: Specifies a DWARF expression that pushes the value of |
2190 | // the canonical frame address consistent with the call frame information |
2191 | // located in .debug_frame (or in the FDEs of the eh_frame section). |
2192 | case DW_OP_call_frame_cfa: |
2193 | if (frame) { |
2194 | // Note that we don't have to parse FDEs because this DWARF expression |
2195 | // is commonly evaluated with a valid stack frame. |
2196 | StackID id = frame->GetStackID(); |
2197 | addr_t cfa = id.GetCallFrameAddress(); |
2198 | if (cfa != LLDB_INVALID_ADDRESS) { |
2199 | stack.push_back(x: Scalar(cfa)); |
2200 | stack.back().SetValueType(Value::ValueType::LoadAddress); |
2201 | } else { |
2202 | return llvm::createStringError( |
2203 | Fmt: "stack frame does not include a canonical " |
2204 | "frame address for DW_OP_call_frame_cfa " |
2205 | "opcode"); |
2206 | } |
2207 | } else { |
2208 | return llvm::createStringError(Fmt: "unvalid stack frame in context for " |
2209 | "DW_OP_call_frame_cfa opcode"); |
2210 | } |
2211 | break; |
2212 | |
2213 | // OPCODE: DW_OP_form_tls_address (or the old pre-DWARFv3 vendor extension |
2214 | // opcode, DW_OP_GNU_push_tls_address) |
2215 | // OPERANDS: none |
2216 | // DESCRIPTION: Pops a TLS offset from the stack, converts it to |
2217 | // an address in the current thread's thread-local storage block, and |
2218 | // pushes it on the stack. |
2219 | case DW_OP_form_tls_address: |
2220 | case DW_OP_GNU_push_tls_address: { |
2221 | if (stack.size() < 1) { |
2222 | if (op == DW_OP_form_tls_address) |
2223 | return llvm::createStringError( |
2224 | Fmt: "DW_OP_form_tls_address needs an argument"); |
2225 | else |
2226 | return llvm::createStringError( |
2227 | Fmt: "DW_OP_GNU_push_tls_address needs an argument"); |
2228 | } |
2229 | |
2230 | if (!exe_ctx || !module_sp) |
2231 | return llvm::createStringError(Fmt: "no context to evaluate TLS within"); |
2232 | |
2233 | Thread *thread = exe_ctx->GetThreadPtr(); |
2234 | if (!thread) |
2235 | return llvm::createStringError(Fmt: "no thread to evaluate TLS within"); |
2236 | |
2237 | // Lookup the TLS block address for this thread and module. |
2238 | const addr_t tls_file_addr = |
2239 | stack.back().GetScalar().ULongLong(LLDB_INVALID_ADDRESS); |
2240 | const addr_t tls_load_addr = |
2241 | thread->GetThreadLocalData(module: module_sp, tls_file_addr); |
2242 | |
2243 | if (tls_load_addr == LLDB_INVALID_ADDRESS) |
2244 | return llvm::createStringError( |
2245 | Fmt: "no TLS data currently exists for this thread"); |
2246 | |
2247 | stack.back().GetScalar() = tls_load_addr; |
2248 | stack.back().SetValueType(Value::ValueType::LoadAddress); |
2249 | } break; |
2250 | |
2251 | // OPCODE: DW_OP_addrx (DW_OP_GNU_addr_index is the legacy name.) |
2252 | // OPERANDS: 1 |
2253 | // ULEB128: index to the .debug_addr section |
2254 | // DESCRIPTION: Pushes an address to the stack from the .debug_addr |
2255 | // section with the base address specified by the DW_AT_addr_base attribute |
2256 | // and the 0 based index is the ULEB128 encoded index. |
2257 | case DW_OP_addrx: |
2258 | case DW_OP_GNU_addr_index: { |
2259 | if (!dwarf_cu) |
2260 | return llvm::createStringError(Fmt: "DW_OP_GNU_addr_index found without a " |
2261 | "compile unit being specified"); |
2262 | uint64_t index = opcodes.GetULEB128(offset_ptr: &offset); |
2263 | lldb::addr_t value = dwarf_cu->ReadAddressFromDebugAddrSection(index); |
2264 | stack.push_back(x: Scalar(value)); |
2265 | if (target && |
2266 | target->GetArchitecture().GetCore() == ArchSpec::eCore_wasm32) { |
2267 | // wasm file sections aren't mapped into memory, therefore addresses can |
2268 | // never point into a file section and are always LoadAddresses. |
2269 | stack.back().SetValueType(Value::ValueType::LoadAddress); |
2270 | } else { |
2271 | stack.back().SetValueType(Value::ValueType::FileAddress); |
2272 | } |
2273 | } break; |
2274 | |
2275 | // OPCODE: DW_OP_GNU_const_index |
2276 | // OPERANDS: 1 |
2277 | // ULEB128: index to the .debug_addr section |
2278 | // DESCRIPTION: Pushes an constant with the size of a machine address to |
2279 | // the stack from the .debug_addr section with the base address specified |
2280 | // by the DW_AT_addr_base attribute and the 0 based index is the ULEB128 |
2281 | // encoded index. |
2282 | case DW_OP_GNU_const_index: { |
2283 | if (!dwarf_cu) { |
2284 | return llvm::createStringError(Fmt: "DW_OP_GNU_const_index found without a " |
2285 | "compile unit being specified"); |
2286 | } |
2287 | uint64_t index = opcodes.GetULEB128(offset_ptr: &offset); |
2288 | lldb::addr_t value = dwarf_cu->ReadAddressFromDebugAddrSection(index); |
2289 | stack.push_back(x: Scalar(value)); |
2290 | } break; |
2291 | |
2292 | case DW_OP_GNU_entry_value: |
2293 | case DW_OP_entry_value: { |
2294 | if (llvm::Error err = Evaluate_DW_OP_entry_value(stack, exe_ctx, reg_ctx, |
2295 | opcodes, opcode_offset&: offset, log)) |
2296 | return llvm::createStringError( |
2297 | Fmt: "could not evaluate DW_OP_entry_value: %s", |
2298 | Vals: llvm::toString(E: std::move(err)).c_str()); |
2299 | break; |
2300 | } |
2301 | |
2302 | default: |
2303 | if (dwarf_cu) { |
2304 | if (dwarf_cu->ParseVendorDWARFOpcode(op, opcodes, offset, stack)) { |
2305 | break; |
2306 | } |
2307 | } |
2308 | return llvm::createStringError(S: llvm::formatv( |
2309 | Fmt: "Unhandled opcode {0} in DWARFExpression", Vals: LocationAtom(op))); |
2310 | } |
2311 | } |
2312 | |
2313 | if (stack.empty()) { |
2314 | // Nothing on the stack, check if we created a piece value from DW_OP_piece |
2315 | // or DW_OP_bit_piece opcodes |
2316 | if (pieces.GetBuffer().GetByteSize()) |
2317 | return pieces; |
2318 | |
2319 | return llvm::createStringError(Fmt: "stack empty after evaluation"); |
2320 | } |
2321 | |
2322 | UpdateValueTypeFromLocationDescription( |
2323 | log, dwarf_cu, kind: dwarf4_location_description_kind, value: &stack.back()); |
2324 | |
2325 | if (log && log->GetVerbose()) { |
2326 | size_t count = stack.size(); |
2327 | LLDB_LOGF(log, |
2328 | "Stack after operation has %"PRIu64 " values:", (uint64_t)count); |
2329 | for (size_t i = 0; i < count; ++i) { |
2330 | StreamString new_value; |
2331 | new_value.Printf(format: "[%"PRIu64 "]", (uint64_t)i); |
2332 | stack[i].Dump(strm: &new_value); |
2333 | LLDB_LOGF(log, " %s", new_value.GetData()); |
2334 | } |
2335 | } |
2336 | return stack.back(); |
2337 | } |
2338 | |
2339 | bool DWARFExpression::MatchesOperand( |
2340 | StackFrame &frame, const Instruction::Operand &operand) const { |
2341 | using namespace OperandMatchers; |
2342 | |
2343 | RegisterContextSP reg_ctx_sp = frame.GetRegisterContext(); |
2344 | if (!reg_ctx_sp) { |
2345 | return false; |
2346 | } |
2347 | |
2348 | DataExtractor opcodes(m_data); |
2349 | |
2350 | lldb::offset_t op_offset = 0; |
2351 | uint8_t opcode = opcodes.GetU8(offset_ptr: &op_offset); |
2352 | |
2353 | if (opcode == DW_OP_fbreg) { |
2354 | int64_t offset = opcodes.GetSLEB128(offset_ptr: &op_offset); |
2355 | |
2356 | DWARFExpressionList *fb_expr = frame.GetFrameBaseExpression(error_ptr: nullptr); |
2357 | if (!fb_expr) { |
2358 | return false; |
2359 | } |
2360 | |
2361 | auto recurse = [&frame, fb_expr](const Instruction::Operand &child) { |
2362 | return fb_expr->MatchesOperand(frame, operand: child); |
2363 | }; |
2364 | |
2365 | if (!offset && |
2366 | MatchUnaryOp(base: MatchOpType(type: Instruction::Operand::Type::Dereference), |
2367 | child: recurse)(operand)) { |
2368 | return true; |
2369 | } |
2370 | |
2371 | return MatchUnaryOp( |
2372 | base: MatchOpType(type: Instruction::Operand::Type::Dereference), |
2373 | child: MatchBinaryOp(base: MatchOpType(type: Instruction::Operand::Type::Sum), |
2374 | left: MatchImmOp(imm: offset), right: recurse))(operand); |
2375 | } |
2376 | |
2377 | bool dereference = false; |
2378 | const RegisterInfo *reg = nullptr; |
2379 | int64_t offset = 0; |
2380 | |
2381 | if (opcode >= DW_OP_reg0 && opcode <= DW_OP_reg31) { |
2382 | reg = reg_ctx_sp->GetRegisterInfo(reg_kind: m_reg_kind, reg_num: opcode - DW_OP_reg0); |
2383 | } else if (opcode >= DW_OP_breg0 && opcode <= DW_OP_breg31) { |
2384 | offset = opcodes.GetSLEB128(offset_ptr: &op_offset); |
2385 | reg = reg_ctx_sp->GetRegisterInfo(reg_kind: m_reg_kind, reg_num: opcode - DW_OP_breg0); |
2386 | } else if (opcode == DW_OP_regx) { |
2387 | uint32_t reg_num = static_cast<uint32_t>(opcodes.GetULEB128(offset_ptr: &op_offset)); |
2388 | reg = reg_ctx_sp->GetRegisterInfo(reg_kind: m_reg_kind, reg_num); |
2389 | } else if (opcode == DW_OP_bregx) { |
2390 | uint32_t reg_num = static_cast<uint32_t>(opcodes.GetULEB128(offset_ptr: &op_offset)); |
2391 | offset = opcodes.GetSLEB128(offset_ptr: &op_offset); |
2392 | reg = reg_ctx_sp->GetRegisterInfo(reg_kind: m_reg_kind, reg_num); |
2393 | } else { |
2394 | return false; |
2395 | } |
2396 | |
2397 | if (!reg) { |
2398 | return false; |
2399 | } |
2400 | |
2401 | if (dereference) { |
2402 | if (!offset && |
2403 | MatchUnaryOp(base: MatchOpType(type: Instruction::Operand::Type::Dereference), |
2404 | child: MatchRegOp(info: *reg))(operand)) { |
2405 | return true; |
2406 | } |
2407 | |
2408 | return MatchUnaryOp( |
2409 | base: MatchOpType(type: Instruction::Operand::Type::Dereference), |
2410 | child: MatchBinaryOp(base: MatchOpType(type: Instruction::Operand::Type::Sum), |
2411 | left: MatchRegOp(info: *reg), |
2412 | right: MatchImmOp(imm: offset)))(operand); |
2413 | } else { |
2414 | return MatchRegOp(info: *reg)(operand); |
2415 | } |
2416 | } |
2417 |
Definitions
- DWARFExpression
- DWARFExpression
- ~DWARFExpression
- IsValid
- UpdateValue
- DumpLocation
- GetRegisterKind
- SetRegisterKind
- ReadRegisterValueAsScalar
- GetOpcodeDataSize
- DW_OP_value_to_name
- GetLocation_DW_OP_addr
- Update_DW_OP_addr
- ContainsThreadLocalStorage
- LinkThreadLocalStorage
- Evaluate_DW_OP_entry_value
- LocationDescriptionKind
- UpdateValueTypeFromLocationDescription
- ResolveLoadAddress
- DerefSizeExtractDataHelper
- Evaluate
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