1//===- DWARFFormValue.h -----------------------------------------*- C++ -*-===//
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#ifndef LLVM_DEBUGINFO_DWARF_DWARFFORMVALUE_H
10#define LLVM_DEBUGINFO_DWARF_DWARFFORMVALUE_H
11
12#include "llvm/ADT/ArrayRef.h"
13#include "llvm/ADT/None.h"
14#include "llvm/ADT/Optional.h"
15#include "llvm/BinaryFormat/Dwarf.h"
16#include "llvm/DebugInfo/DIContext.h"
17#include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
18#include <cstdint>
19
20namespace llvm {
21
22class DWARFContext;
23class DWARFUnit;
24class raw_ostream;
25
26class DWARFFormValue {
27public:
28 enum FormClass {
29 FC_Unknown,
30 FC_Address,
31 FC_Block,
32 FC_Constant,
33 FC_String,
34 FC_Flag,
35 FC_Reference,
36 FC_Indirect,
37 FC_SectionOffset,
38 FC_Exprloc
39 };
40
41private:
42 struct ValueType {
43 ValueType() { uval = 0; }
44 ValueType(int64_t V) : sval(V) {}
45 ValueType(uint64_t V) : uval(V) {}
46 ValueType(const char *V) : cstr(V) {}
47
48 union {
49 uint64_t uval;
50 int64_t sval;
51 const char *cstr;
52 };
53 const uint8_t *data = nullptr;
54 uint64_t SectionIndex; /// Section index for reference forms.
55 };
56
57 dwarf::Form Form; /// Form for this value.
58 dwarf::DwarfFormat Format =
59 dwarf::DWARF32; /// Remember the DWARF format at extract time.
60 ValueType Value; /// Contains all data for the form.
61 const DWARFUnit *U = nullptr; /// Remember the DWARFUnit at extract time.
62 const DWARFContext *C = nullptr; /// Context for extract time.
63
64 DWARFFormValue(dwarf::Form F, ValueType V) : Form(F), Value(V) {}
65
66public:
67 DWARFFormValue(dwarf::Form F = dwarf::Form(0)) : Form(F) {}
68
69 static DWARFFormValue createFromSValue(dwarf::Form F, int64_t V);
70 static DWARFFormValue createFromUValue(dwarf::Form F, uint64_t V);
71 static DWARFFormValue createFromPValue(dwarf::Form F, const char *V);
72 static DWARFFormValue createFromBlockValue(dwarf::Form F,
73 ArrayRef<uint8_t> D);
74 static DWARFFormValue createFromUnit(dwarf::Form F, const DWARFUnit *Unit,
75 uint64_t *OffsetPtr);
76
77 dwarf::Form getForm() const { return Form; }
78 uint64_t getRawUValue() const { return Value.uval; }
79
80 bool isFormClass(FormClass FC) const;
81 const DWARFUnit *getUnit() const { return U; }
82 void dump(raw_ostream &OS, DIDumpOptions DumpOpts = DIDumpOptions()) const;
83 void dumpSectionedAddress(raw_ostream &OS, DIDumpOptions DumpOpts,
84 object::SectionedAddress SA) const;
85 void dumpAddress(raw_ostream &OS, uint64_t Address) const;
86 static void dumpAddress(raw_ostream &OS, uint8_t AddressSize,
87 uint64_t Address);
88 static void dumpAddressSection(const DWARFObject &Obj, raw_ostream &OS,
89 DIDumpOptions DumpOpts, uint64_t SectionIndex);
90
91 /// Extracts a value in \p Data at offset \p *OffsetPtr. The information
92 /// in \p FormParams is needed to interpret some forms. The optional
93 /// \p Context and \p Unit allows extracting information if the form refers
94 /// to other sections (e.g., .debug_str).
95 bool extractValue(const DWARFDataExtractor &Data, uint64_t *OffsetPtr,
96 dwarf::FormParams FormParams,
97 const DWARFContext *Context = nullptr,
98 const DWARFUnit *Unit = nullptr);
99
100 bool extractValue(const DWARFDataExtractor &Data, uint64_t *OffsetPtr,
101 dwarf::FormParams FormParams, const DWARFUnit *U) {
102 return extractValue(Data, OffsetPtr, FormParams, nullptr, U);
103 }
104
105 bool isInlinedCStr() const {
106 return Value.data != nullptr && Value.data == (const uint8_t *)Value.cstr;
107 }
108
109 /// getAsFoo functions below return the extracted value as Foo if only
110 /// DWARFFormValue has form class is suitable for representing Foo.
111 Optional<uint64_t> getAsReference() const;
112 struct UnitOffset {
113 DWARFUnit *Unit;
114 uint64_t Offset;
115 };
116 Optional<UnitOffset> getAsRelativeReference() const;
117 Optional<uint64_t> getAsUnsignedConstant() const;
118 Optional<int64_t> getAsSignedConstant() const;
119 Optional<const char *> getAsCString() const;
120 Optional<uint64_t> getAsAddress() const;
121 Optional<object::SectionedAddress> getAsSectionedAddress() const;
122 Optional<uint64_t> getAsSectionOffset() const;
123 Optional<ArrayRef<uint8_t>> getAsBlock() const;
124 Optional<uint64_t> getAsCStringOffset() const;
125 Optional<uint64_t> getAsReferenceUVal() const;
126
127 /// Skip a form's value in \p DebugInfoData at the offset specified by
128 /// \p OffsetPtr.
129 ///
130 /// Skips the bytes for the current form and updates the offset.
131 ///
132 /// \param DebugInfoData The data where we want to skip the value.
133 /// \param OffsetPtr A reference to the offset that will be updated.
134 /// \param Params DWARF parameters to help interpret forms.
135 /// \returns true on success, false if the form was not skipped.
136 bool skipValue(DataExtractor DebugInfoData, uint64_t *OffsetPtr,
137 const dwarf::FormParams Params) const {
138 return DWARFFormValue::skipValue(Form, DebugInfoData, OffsetPtr, Params);
139 }
140
141 /// Skip a form's value in \p DebugInfoData at the offset specified by
142 /// \p OffsetPtr.
143 ///
144 /// Skips the bytes for the specified form and updates the offset.
145 ///
146 /// \param Form The DW_FORM enumeration that indicates the form to skip.
147 /// \param DebugInfoData The data where we want to skip the value.
148 /// \param OffsetPtr A reference to the offset that will be updated.
149 /// \param FormParams DWARF parameters to help interpret forms.
150 /// \returns true on success, false if the form was not skipped.
151 static bool skipValue(dwarf::Form Form, DataExtractor DebugInfoData,
152 uint64_t *OffsetPtr,
153 const dwarf::FormParams FormParams);
154
155private:
156 void dumpString(raw_ostream &OS) const;
157};
158
159namespace dwarf {
160
161/// Take an optional DWARFFormValue and try to extract a string value from it.
162///
163/// \param V and optional DWARFFormValue to attempt to extract the value from.
164/// \returns an optional value that contains a value if the form value
165/// was valid and was a string.
166inline Optional<const char *> toString(const Optional<DWARFFormValue> &V) {
167 if (V)
168 return V->getAsCString();
169 return None;
170}
171
172/// Take an optional DWARFFormValue and try to extract a string value from it.
173///
174/// \param V and optional DWARFFormValue to attempt to extract the value from.
175/// \returns an optional value that contains a value if the form value
176/// was valid and was a string.
177inline StringRef toStringRef(const Optional<DWARFFormValue> &V,
178 StringRef Default = {}) {
179 if (V)
180 if (auto S = V->getAsCString())
181 return *S;
182 return Default;
183}
184
185/// Take an optional DWARFFormValue and extract a string value from it.
186///
187/// \param V and optional DWARFFormValue to attempt to extract the value from.
188/// \param Default the default value to return in case of failure.
189/// \returns the string value or Default if the V doesn't have a value or the
190/// form value's encoding wasn't a string.
191inline const char *toString(const Optional<DWARFFormValue> &V,
192 const char *Default) {
193 return toString(V).getValueOr(Default);
194}
195
196/// Take an optional DWARFFormValue and try to extract an unsigned constant.
197///
198/// \param V and optional DWARFFormValue to attempt to extract the value from.
199/// \returns an optional value that contains a value if the form value
200/// was valid and has a unsigned constant form.
201inline Optional<uint64_t> toUnsigned(const Optional<DWARFFormValue> &V) {
202 if (V)
203 return V->getAsUnsignedConstant();
204 return None;
205}
206
207/// Take an optional DWARFFormValue and extract a unsigned constant.
208///
209/// \param V and optional DWARFFormValue to attempt to extract the value from.
210/// \param Default the default value to return in case of failure.
211/// \returns the extracted unsigned value or Default if the V doesn't have a
212/// value or the form value's encoding wasn't an unsigned constant form.
213inline uint64_t toUnsigned(const Optional<DWARFFormValue> &V,
214 uint64_t Default) {
215 return toUnsigned(V).getValueOr(Default);
216}
217
218/// Take an optional DWARFFormValue and try to extract an reference.
219///
220/// \param V and optional DWARFFormValue to attempt to extract the value from.
221/// \returns an optional value that contains a value if the form value
222/// was valid and has a reference form.
223inline Optional<uint64_t> toReference(const Optional<DWARFFormValue> &V) {
224 if (V)
225 return V->getAsReference();
226 return None;
227}
228
229/// Take an optional DWARFFormValue and extract a reference.
230///
231/// \param V and optional DWARFFormValue to attempt to extract the value from.
232/// \param Default the default value to return in case of failure.
233/// \returns the extracted reference value or Default if the V doesn't have a
234/// value or the form value's encoding wasn't a reference form.
235inline uint64_t toReference(const Optional<DWARFFormValue> &V,
236 uint64_t Default) {
237 return toReference(V).getValueOr(Default);
238}
239
240/// Take an optional DWARFFormValue and try to extract an signed constant.
241///
242/// \param V and optional DWARFFormValue to attempt to extract the value from.
243/// \returns an optional value that contains a value if the form value
244/// was valid and has a signed constant form.
245inline Optional<int64_t> toSigned(const Optional<DWARFFormValue> &V) {
246 if (V)
247 return V->getAsSignedConstant();
248 return None;
249}
250
251/// Take an optional DWARFFormValue and extract a signed integer.
252///
253/// \param V and optional DWARFFormValue to attempt to extract the value from.
254/// \param Default the default value to return in case of failure.
255/// \returns the extracted signed integer value or Default if the V doesn't
256/// have a value or the form value's encoding wasn't a signed integer form.
257inline int64_t toSigned(const Optional<DWARFFormValue> &V, int64_t Default) {
258 return toSigned(V).getValueOr(Default);
259}
260
261/// Take an optional DWARFFormValue and try to extract an address.
262///
263/// \param V and optional DWARFFormValue to attempt to extract the value from.
264/// \returns an optional value that contains a value if the form value
265/// was valid and has a address form.
266inline Optional<uint64_t> toAddress(const Optional<DWARFFormValue> &V) {
267 if (V)
268 return V->getAsAddress();
269 return None;
270}
271
272inline Optional<object::SectionedAddress>
273toSectionedAddress(const Optional<DWARFFormValue> &V) {
274 if (V)
275 return V->getAsSectionedAddress();
276 return None;
277}
278
279/// Take an optional DWARFFormValue and extract a address.
280///
281/// \param V and optional DWARFFormValue to attempt to extract the value from.
282/// \param Default the default value to return in case of failure.
283/// \returns the extracted address value or Default if the V doesn't have a
284/// value or the form value's encoding wasn't an address form.
285inline uint64_t toAddress(const Optional<DWARFFormValue> &V, uint64_t Default) {
286 return toAddress(V).getValueOr(Default);
287}
288
289/// Take an optional DWARFFormValue and try to extract an section offset.
290///
291/// \param V and optional DWARFFormValue to attempt to extract the value from.
292/// \returns an optional value that contains a value if the form value
293/// was valid and has a section offset form.
294inline Optional<uint64_t> toSectionOffset(const Optional<DWARFFormValue> &V) {
295 if (V)
296 return V->getAsSectionOffset();
297 return None;
298}
299
300/// Take an optional DWARFFormValue and extract a section offset.
301///
302/// \param V and optional DWARFFormValue to attempt to extract the value from.
303/// \param Default the default value to return in case of failure.
304/// \returns the extracted section offset value or Default if the V doesn't
305/// have a value or the form value's encoding wasn't a section offset form.
306inline uint64_t toSectionOffset(const Optional<DWARFFormValue> &V,
307 uint64_t Default) {
308 return toSectionOffset(V).getValueOr(Default);
309}
310
311/// Take an optional DWARFFormValue and try to extract block data.
312///
313/// \param V and optional DWARFFormValue to attempt to extract the value from.
314/// \returns an optional value that contains a value if the form value
315/// was valid and has a block form.
316inline Optional<ArrayRef<uint8_t>> toBlock(const Optional<DWARFFormValue> &V) {
317 if (V)
318 return V->getAsBlock();
319 return None;
320}
321
322} // end namespace dwarf
323
324} // end namespace llvm
325
326#endif // LLVM_DEBUGINFO_DWARF_DWARFFORMVALUE_H
327