LLVM 20.0.0git
DWARFDebugLoc.cpp
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1//===- DWARFDebugLoc.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
10#include "llvm/ADT/StringRef.h"
18#include "llvm/Support/Format.h"
20#include <algorithm>
21#include <cinttypes>
22#include <cstdint>
23
24using namespace llvm;
26
27namespace llvm {
28class DWARFObject;
29}
30
31namespace {
32class DWARFLocationInterpreter {
33 std::optional<object::SectionedAddress> Base;
34 std::function<std::optional<object::SectionedAddress>(uint32_t)> LookupAddr;
35
36public:
37 DWARFLocationInterpreter(
38 std::optional<object::SectionedAddress> Base,
39 std::function<std::optional<object::SectionedAddress>(uint32_t)>
40 LookupAddr)
41 : Base(Base), LookupAddr(std::move(LookupAddr)) {}
42
44 Interpret(const DWARFLocationEntry &E);
45};
46} // namespace
47
48static Error createResolverError(uint32_t Index, unsigned Kind) {
49 return make_error<ResolverError>(Index, (dwarf::LoclistEntries)Kind);
50}
51
53DWARFLocationInterpreter::Interpret(const DWARFLocationEntry &E) {
54 switch (E.Kind) {
55 case dwarf::DW_LLE_end_of_list:
56 return std::nullopt;
57 case dwarf::DW_LLE_base_addressx: {
58 Base = LookupAddr(E.Value0);
59 if (!Base)
60 return createResolverError(E.Value0, E.Kind);
61 return std::nullopt;
62 }
63 case dwarf::DW_LLE_startx_endx: {
64 std::optional<SectionedAddress> LowPC = LookupAddr(E.Value0);
65 if (!LowPC)
66 return createResolverError(E.Value0, E.Kind);
67 std::optional<SectionedAddress> HighPC = LookupAddr(E.Value1);
68 if (!HighPC)
69 return createResolverError(E.Value1, E.Kind);
71 DWARFAddressRange{LowPC->Address, HighPC->Address, LowPC->SectionIndex},
72 E.Loc};
73 }
74 case dwarf::DW_LLE_startx_length: {
75 std::optional<SectionedAddress> LowPC = LookupAddr(E.Value0);
76 if (!LowPC)
77 return createResolverError(E.Value0, E.Kind);
78 return DWARFLocationExpression{DWARFAddressRange{LowPC->Address,
79 LowPC->Address + E.Value1,
80 LowPC->SectionIndex},
81 E.Loc};
82 }
83 case dwarf::DW_LLE_offset_pair: {
84 if (!Base) {
86 "Unable to resolve location list offset pair: "
87 "Base address not defined");
88 }
89 DWARFAddressRange Range{Base->Address + E.Value0, Base->Address + E.Value1,
90 Base->SectionIndex};
91 if (Range.SectionIndex == SectionedAddress::UndefSection)
92 Range.SectionIndex = E.SectionIndex;
94 }
95 case dwarf::DW_LLE_default_location:
96 return DWARFLocationExpression{std::nullopt, E.Loc};
97 case dwarf::DW_LLE_base_address:
99 return std::nullopt;
100 case dwarf::DW_LLE_start_end:
103 case dwarf::DW_LLE_start_length:
106 E.Loc};
107 default:
108 llvm_unreachable("unreachable locations list kind");
109 }
110}
111
113 ArrayRef<uint8_t> Data, bool IsLittleEndian,
114 unsigned AddressSize, DWARFUnit *U) {
115 DWARFDataExtractor Extractor(Data, IsLittleEndian, AddressSize);
116 std::optional<dwarf::DwarfFormat> Format;
117 if (U)
118 Format = U->getFormat();
119 DWARFExpression(Extractor, AddressSize, Format).print(OS, DumpOpts, U);
120}
121
123 uint64_t *Offset, raw_ostream &OS, std::optional<SectionedAddress> BaseAddr,
124 const DWARFObject &Obj, DWARFUnit *U, DIDumpOptions DumpOpts,
125 unsigned Indent) const {
126 DWARFLocationInterpreter Interp(
127 BaseAddr, [U](uint32_t Index) -> std::optional<SectionedAddress> {
128 if (U)
129 return U->getAddrOffsetSectionItem(Index);
130 return std::nullopt;
131 });
132 OS << format("0x%8.8" PRIx64 ": ", *Offset);
134 Expected<std::optional<DWARFLocationExpression>> Loc = Interp.Interpret(E);
135 if (!Loc || DumpOpts.DisplayRawContents)
136 dumpRawEntry(E, OS, Indent, DumpOpts, Obj);
137 if (Loc && *Loc) {
138 OS << "\n";
139 OS.indent(Indent);
140 if (DumpOpts.DisplayRawContents)
141 OS << " => ";
142
143 DIDumpOptions RangeDumpOpts(DumpOpts);
144 RangeDumpOpts.DisplayRawContents = false;
145 if (Loc.get()->Range)
146 Loc.get()->Range->dump(OS, Data.getAddressSize(), RangeDumpOpts, &Obj);
147 else
148 OS << "<default>";
149 }
150 if (!Loc)
151 consumeError(Loc.takeError());
152
153 if (E.Kind != dwarf::DW_LLE_base_address &&
154 E.Kind != dwarf::DW_LLE_base_addressx &&
155 E.Kind != dwarf::DW_LLE_end_of_list) {
156 OS << ": ";
157 dumpExpression(OS, DumpOpts, E.Loc, Data.isLittleEndian(),
158 Data.getAddressSize(), U);
159 }
160 return true;
161 });
162 if (E) {
163 DumpOpts.RecoverableErrorHandler(std::move(E));
164 return false;
165 }
166 return true;
167}
168
170 uint64_t Offset, std::optional<SectionedAddress> BaseAddr,
171 std::function<std::optional<SectionedAddress>(uint32_t)> LookupAddr,
172 function_ref<bool(Expected<DWARFLocationExpression>)> Callback) const {
173 DWARFLocationInterpreter Interp(BaseAddr, std::move(LookupAddr));
174 return visitLocationList(&Offset, [&](const DWARFLocationEntry &E) {
175 Expected<std::optional<DWARFLocationExpression>> Loc = Interp.Interpret(E);
176 if (!Loc)
177 return Callback(Loc.takeError());
178 if (*Loc)
179 return Callback(**Loc);
180 return true;
181 });
182}
183
185 DIDumpOptions DumpOpts,
186 std::optional<uint64_t> DumpOffset) const {
187 auto BaseAddr = std::nullopt;
188 unsigned Indent = 12;
189 if (DumpOffset) {
190 dumpLocationList(&*DumpOffset, OS, BaseAddr, Obj, nullptr, DumpOpts,
191 Indent);
192 } else {
193 uint64_t Offset = 0;
194 StringRef Separator;
195 bool CanContinue = true;
196 while (CanContinue && Data.isValidOffset(Offset)) {
197 OS << Separator;
198 Separator = "\n";
199
200 CanContinue = dumpLocationList(&Offset, OS, BaseAddr, Obj, nullptr,
201 DumpOpts, Indent);
202 OS << '\n';
203 }
204 }
205}
206
209 function_ref<bool(const DWARFLocationEntry &)> Callback) const {
211 while (true) {
212 uint64_t SectionIndex;
214 uint64_t Value1 = Data.getRelocatedAddress(C, &SectionIndex);
215
217
218 // The end of any given location list is marked by an end of list entry,
219 // which consists of a 0 for the beginning address offset and a 0 for the
220 // ending address offset. A beginning offset of 0xff...f marks the base
221 // address selection entry.
222 if (Value0 == 0 && Value1 == 0) {
223 E.Kind = dwarf::DW_LLE_end_of_list;
224 } else if (Value0 == (Data.getAddressSize() == 4 ? -1U : -1ULL)) {
225 E.Kind = dwarf::DW_LLE_base_address;
226 E.Value0 = Value1;
227 E.SectionIndex = SectionIndex;
228 } else {
229 E.Kind = dwarf::DW_LLE_offset_pair;
230 E.Value0 = Value0;
231 E.Value1 = Value1;
232 E.SectionIndex = SectionIndex;
233 unsigned Bytes = Data.getU16(C);
234 // A single location description describing the location of the object...
235 Data.getU8(C, E.Loc, Bytes);
236 }
237
238 if (!C)
239 return C.takeError();
240 if (!Callback(E) || E.Kind == dwarf::DW_LLE_end_of_list)
241 break;
242 }
243 *Offset = C.tell();
244 return Error::success();
245}
246
248 raw_ostream &OS, unsigned Indent,
249 DIDumpOptions DumpOpts,
250 const DWARFObject &Obj) const {
251 uint64_t Value0, Value1;
252 switch (Entry.Kind) {
253 case dwarf::DW_LLE_base_address:
254 Value0 = Data.getAddressSize() == 4 ? -1U : -1ULL;
255 Value1 = Entry.Value0;
256 break;
257 case dwarf::DW_LLE_offset_pair:
258 Value0 = Entry.Value0;
259 Value1 = Entry.Value1;
260 break;
261 case dwarf::DW_LLE_end_of_list:
262 return;
263 default:
264 llvm_unreachable("Not possible in DWARF4!");
265 }
266 OS << '\n';
267 OS.indent(Indent);
268 OS << '(' << format_hex(Value0, 2 + Data.getAddressSize() * 2) << ", "
269 << format_hex(Value1, 2 + Data.getAddressSize() * 2) << ')';
270 DWARFFormValue::dumpAddressSection(Obj, OS, DumpOpts, Entry.SectionIndex);
271}
272
274 uint64_t *Offset, function_ref<bool(const DWARFLocationEntry &)> F) const {
275
277 bool Continue = true;
278 while (Continue) {
280 E.Kind = Data.getU8(C);
281 switch (E.Kind) {
282 case dwarf::DW_LLE_end_of_list:
283 break;
284 case dwarf::DW_LLE_base_addressx:
285 E.Value0 = Data.getULEB128(C);
286 break;
287 case dwarf::DW_LLE_startx_endx:
288 E.Value0 = Data.getULEB128(C);
289 E.Value1 = Data.getULEB128(C);
290 break;
291 case dwarf::DW_LLE_startx_length:
292 E.Value0 = Data.getULEB128(C);
293 // Pre-DWARF 5 has different interpretation of the length field. We have
294 // to support both pre- and standartized styles for the compatibility.
295 if (Version < 5)
296 E.Value1 = Data.getU32(C);
297 else
298 E.Value1 = Data.getULEB128(C);
299 break;
300 case dwarf::DW_LLE_offset_pair:
301 E.Value0 = Data.getULEB128(C);
302 E.Value1 = Data.getULEB128(C);
304 break;
305 case dwarf::DW_LLE_default_location:
306 break;
307 case dwarf::DW_LLE_base_address:
309 break;
310 case dwarf::DW_LLE_start_end:
313 break;
314 case dwarf::DW_LLE_start_length:
316 E.Value1 = Data.getULEB128(C);
317 break;
318 default:
319 cantFail(C.takeError());
321 "LLE of kind %x not supported", (int)E.Kind);
322 }
323
324 if (E.Kind != dwarf::DW_LLE_base_address &&
325 E.Kind != dwarf::DW_LLE_base_addressx &&
326 E.Kind != dwarf::DW_LLE_end_of_list) {
327 unsigned Bytes = Version >= 5 ? Data.getULEB128(C) : Data.getU16(C);
328 // A single location description describing the location of the object...
329 Data.getU8(C, E.Loc, Bytes);
330 }
331
332 if (!C)
333 return C.takeError();
334 Continue = F(E) && E.Kind != dwarf::DW_LLE_end_of_list;
335 }
336 *Offset = C.tell();
337 return Error::success();
338}
339
341 raw_ostream &OS, unsigned Indent,
342 DIDumpOptions DumpOpts,
343 const DWARFObject &Obj) const {
344 size_t MaxEncodingStringLength = 0;
345#define HANDLE_DW_LLE(ID, NAME) \
346 MaxEncodingStringLength = std::max(MaxEncodingStringLength, \
347 dwarf::LocListEncodingString(ID).size());
348#include "llvm/BinaryFormat/Dwarf.def"
349
350 OS << "\n";
351 OS.indent(Indent);
352 StringRef EncodingString = dwarf::LocListEncodingString(Entry.Kind);
353 // Unsupported encodings should have been reported during parsing.
354 assert(!EncodingString.empty() && "Unknown loclist entry encoding");
355 OS << format("%-*s(", MaxEncodingStringLength, EncodingString.data());
356 unsigned FieldSize = 2 + 2 * Data.getAddressSize();
357 switch (Entry.Kind) {
358 case dwarf::DW_LLE_end_of_list:
359 case dwarf::DW_LLE_default_location:
360 break;
361 case dwarf::DW_LLE_startx_endx:
362 case dwarf::DW_LLE_startx_length:
363 case dwarf::DW_LLE_offset_pair:
364 case dwarf::DW_LLE_start_end:
365 case dwarf::DW_LLE_start_length:
366 OS << format_hex(Entry.Value0, FieldSize) << ", "
367 << format_hex(Entry.Value1, FieldSize);
368 break;
369 case dwarf::DW_LLE_base_addressx:
370 case dwarf::DW_LLE_base_address:
371 OS << format_hex(Entry.Value0, FieldSize);
372 break;
373 }
374 OS << ')';
375 switch (Entry.Kind) {
376 case dwarf::DW_LLE_base_address:
377 case dwarf::DW_LLE_start_end:
378 case dwarf::DW_LLE_start_length:
379 DWARFFormValue::dumpAddressSection(Obj, OS, DumpOpts, Entry.SectionIndex);
380 break;
381 default:
382 break;
383 }
384}
385
387 raw_ostream &OS, const DWARFObject &Obj,
388 DIDumpOptions DumpOpts) {
389 if (!Data.isValidOffsetForDataOfSize(StartOffset, Size)) {
390 OS << "Invalid dump range\n";
391 return;
392 }
393 uint64_t Offset = StartOffset;
394 StringRef Separator;
395 bool CanContinue = true;
396 while (CanContinue && Offset < StartOffset + Size) {
397 OS << Separator;
398 Separator = "\n";
399
400 CanContinue = dumpLocationList(&Offset, OS, /*BaseAddr=*/std::nullopt, Obj,
401 nullptr, DumpOpts, /*Indent=*/12);
402 OS << '\n';
403 }
404}
405
407 OS << format("unable to resolve indirect address %u for: %s", Index,
408 dwarf::LocListEncodingString(Kind).data());
409}
410
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
static void dumpExpression(raw_ostream &OS, DIDumpOptions DumpOpts, ArrayRef< uint8_t > Data, bool IsLittleEndian, unsigned AddressSize, DWARFUnit *U)
static Error createResolverError(uint32_t Index, unsigned Kind)
This file contains constants used for implementing Dwarf debug support.
uint64_t Size
#define F(x, y, z)
Definition: MD5.cpp:55
ConstantRange Range(APInt(BitWidth, Low), APInt(BitWidth, High))
if(PassOpts->AAPipeline)
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
raw_pwrite_stream & OS
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory),...
Definition: ArrayRef.h:41
A DataExtractor (typically for an in-memory copy of an object-file section) plus a relocation map for...
uint64_t getRelocatedAddress(uint64_t *Off, uint64_t *SecIx=nullptr) const
Extracts an address-sized value and applies a relocation to the result if one exists for the given of...
void dumpRawEntry(const DWARFLocationEntry &Entry, raw_ostream &OS, unsigned Indent, DIDumpOptions DumpOpts, const DWARFObject &Obj) const override
void dump(raw_ostream &OS, const DWARFObject &Obj, DIDumpOptions DumpOpts, std::optional< uint64_t > Offset) const
Print the location lists found within the debug_loc section.
Error visitLocationList(uint64_t *Offset, function_ref< bool(const DWARFLocationEntry &)> Callback) const override
Call the user-provided callback for each entry (including the end-of-list entry) in the location list...
void dumpRange(uint64_t StartOffset, uint64_t Size, raw_ostream &OS, const DWARFObject &Obj, DIDumpOptions DumpOpts)
Dump all location lists within the given range.
Error visitLocationList(uint64_t *Offset, function_ref< bool(const DWARFLocationEntry &)> Callback) const override
Call the user-provided callback for each entry (including the end-of-list entry) in the location list...
void dumpRawEntry(const DWARFLocationEntry &Entry, raw_ostream &OS, unsigned Indent, DIDumpOptions DumpOpts, const DWARFObject &Obj) const override
void print(raw_ostream &OS, DIDumpOptions DumpOpts, DWARFUnit *U, bool IsEH=false) const
static void dumpAddressSection(const DWARFObject &Obj, raw_ostream &OS, DIDumpOptions DumpOpts, uint64_t SectionIndex)
virtual void dumpRawEntry(const DWARFLocationEntry &Entry, raw_ostream &OS, unsigned Indent, DIDumpOptions DumpOpts, const DWARFObject &Obj) const =0
DWARFDataExtractor Data
Definition: DWARFDebugLoc.h:81
virtual Error visitLocationList(uint64_t *Offset, function_ref< bool(const DWARFLocationEntry &)> Callback) const =0
Call the user-provided callback for each entry (including the end-of-list entry) in the location list...
Error visitAbsoluteLocationList(uint64_t Offset, std::optional< object::SectionedAddress > BaseAddr, std::function< std::optional< object::SectionedAddress >(uint32_t)> LookupAddr, function_ref< bool(Expected< DWARFLocationExpression >)> Callback) const
bool dumpLocationList(uint64_t *Offset, raw_ostream &OS, std::optional< object::SectionedAddress > BaseAddr, const DWARFObject &Obj, DWARFUnit *U, DIDumpOptions DumpOpts, unsigned Indent) const
Dump the location list at the given Offset.
A class representing a position in a DataExtractor, as well as any error encountered during extractio...
Definition: DataExtractor.h:54
uint32_t getU32(uint64_t *offset_ptr, Error *Err=nullptr) const
Extract a uint32_t value from *offset_ptr.
uint8_t getU8(uint64_t *offset_ptr, Error *Err=nullptr) const
Extract a uint8_t value from *offset_ptr.
uint64_t getULEB128(uint64_t *offset_ptr, llvm::Error *Err=nullptr) const
Extract a unsigned LEB128 value from *offset_ptr.
uint8_t getAddressSize() const
Get the address size for this extractor.
Definition: DataExtractor.h:99
uint16_t getU16(uint64_t *offset_ptr, Error *Err=nullptr) const
Extract a uint16_t value from *offset_ptr.
bool isValidOffset(uint64_t offset) const
Test the validity of offset.
bool isValidOffsetForDataOfSize(uint64_t offset, uint64_t length) const
Test the availability of length bytes of data from offset.
Lightweight error class with error context and mandatory checking.
Definition: Error.h:160
static ErrorSuccess success()
Create a success value.
Definition: Error.h:337
Tagged union holding either a T or a Error.
Definition: Error.h:481
Error takeError()
Take ownership of the stored error.
Definition: Error.h:608
reference get()
Returns a reference to the stored T value.
Definition: Error.h:578
void log(raw_ostream &OS) const override
Print an error message to an output stream.
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:50
constexpr bool empty() const
empty - Check if the string is empty.
Definition: StringRef.h:134
constexpr const char * data() const
data - Get a pointer to the start of the string (which may not be null terminated).
Definition: StringRef.h:131
An efficient, type-erasing, non-owning reference to a callable.
This class implements an extremely fast bulk output stream that can only output to a stream.
Definition: raw_ostream.h:52
raw_ostream & indent(unsigned NumSpaces)
indent - Insert 'NumSpaces' spaces.
StringRef LocListEncodingString(unsigned Encoding)
Definition: Dwarf.cpp:602
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
@ C
The default llvm calling convention, compatible with C.
Definition: CallingConv.h:34
LoclistEntries
DWARF v5 loc list entry encoding values.
Definition: Dwarf.h:819
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
@ Offset
Definition: DWP.cpp:480
std::error_code inconvertibleErrorCode()
The value returned by this function can be returned from convertToErrorCode for Error values where no...
Definition: Error.cpp:98
Error createStringError(std::error_code EC, char const *Fmt, const Ts &... Vals)
Create formatted StringError object.
Definition: Error.h:1286
@ illegal_byte_sequence
FormattedNumber format_hex(uint64_t N, unsigned Width, bool Upper=false)
format_hex - Output N as a fixed width hexadecimal.
Definition: Format.h:187
format_object< Ts... > format(const char *Fmt, const Ts &... Vals)
These are helper functions used to produce formatted output.
Definition: Format.h:125
void cantFail(Error Err, const char *Msg=nullptr)
Report a fatal error if Err is a failure value.
Definition: Error.h:756
OutputIt move(R &&Range, OutputIt Out)
Provide wrappers to std::move which take ranges instead of having to pass begin/end explicitly.
Definition: STLExtras.h:1849
@ Continue
Definition: DWP.h:21
void consumeError(Error Err)
Consume a Error without doing anything.
Definition: Error.h:1069
Implement std::hash so that hash_code can be used in STL containers.
Definition: BitVector.h:858
Container for dump options that control which debug information will be dumped.
Definition: DIContext.h:196
std::function< void(Error)> RecoverableErrorHandler
Definition: DIContext.h:234
A single location within a location list.
Definition: DWARFDebugLoc.h:30
SmallVector< uint8_t, 4 > Loc
The location expression itself (if applicable).
Definition: DWARFDebugLoc.h:44
uint8_t Kind
The entry kind (DW_LLE_***).
Definition: DWARFDebugLoc.h:32
uint64_t Value1
The second value of the location entry (if applicable).
Definition: DWARFDebugLoc.h:38
uint64_t SectionIndex
The index of the section this entry is relative to (if applicable).
Definition: DWARFDebugLoc.h:41
uint64_t Value0
The first value of the location entry (if applicable).
Definition: DWARFDebugLoc.h:35
Represents a single DWARF expression, whose value is location-dependent.
static const uint64_t UndefSection
Definition: ObjectFile.h:146