Line data Source code
1 : //===-- AsmPrinterDwarf.cpp - AsmPrinter Dwarf Support --------------------===//
2 : //
3 : // The LLVM Compiler Infrastructure
4 : //
5 : // This file is distributed under the University of Illinois Open Source
6 : // License. See LICENSE.TXT for details.
7 : //
8 : //===----------------------------------------------------------------------===//
9 : //
10 : // This file implements the Dwarf emissions parts of AsmPrinter.
11 : //
12 : //===----------------------------------------------------------------------===//
13 :
14 : #include "ByteStreamer.h"
15 : #include "llvm/ADT/Twine.h"
16 : #include "llvm/BinaryFormat/Dwarf.h"
17 : #include "llvm/CodeGen/AsmPrinter.h"
18 : #include "llvm/CodeGen/DIE.h"
19 : #include "llvm/CodeGen/MachineFunction.h"
20 : #include "llvm/IR/DataLayout.h"
21 : #include "llvm/MC/MCAsmInfo.h"
22 : #include "llvm/MC/MCRegisterInfo.h"
23 : #include "llvm/MC/MCSection.h"
24 : #include "llvm/MC/MCStreamer.h"
25 : #include "llvm/MC/MCSymbol.h"
26 : #include "llvm/MC/MachineLocation.h"
27 : #include "llvm/Support/ErrorHandling.h"
28 : #include "llvm/Target/TargetLoweringObjectFile.h"
29 : #include "llvm/Target/TargetMachine.h"
30 : using namespace llvm;
31 :
32 : #define DEBUG_TYPE "asm-printer"
33 :
34 : //===----------------------------------------------------------------------===//
35 : // Dwarf Emission Helper Routines
36 : //===----------------------------------------------------------------------===//
37 :
38 : /// EmitSLEB128 - emit the specified signed leb128 value.
39 84585 : void AsmPrinter::EmitSLEB128(int64_t Value, const char *Desc) const {
40 84585 : if (isVerbose() && Desc)
41 0 : OutStreamer->AddComment(Desc);
42 :
43 84585 : OutStreamer->EmitSLEB128IntValue(Value);
44 84585 : }
45 :
46 1447468 : void AsmPrinter::EmitULEB128(uint64_t Value, const char *Desc) const {
47 1447468 : if (isVerbose() && Desc)
48 53084 : OutStreamer->AddComment(Desc);
49 :
50 1447468 : OutStreamer->EmitULEB128IntValue(Value);
51 1447472 : }
52 :
53 : /// Emit something like ".uleb128 Hi-Lo".
54 1557752 : void AsmPrinter::EmitLabelDifferenceAsULEB128(const MCSymbol *Hi,
55 : const MCSymbol *Lo) const {
56 1557752 : OutStreamer->emitAbsoluteSymbolDiffAsULEB128(Hi, Lo);
57 1557752 : }
58 :
59 864 : static const char *DecodeDWARFEncoding(unsigned Encoding) {
60 864 : switch (Encoding) {
61 : case dwarf::DW_EH_PE_absptr:
62 : return "absptr";
63 379 : case dwarf::DW_EH_PE_omit:
64 379 : return "omit";
65 0 : case dwarf::DW_EH_PE_pcrel:
66 0 : return "pcrel";
67 256 : case dwarf::DW_EH_PE_uleb128:
68 256 : return "uleb128";
69 0 : case dwarf::DW_EH_PE_sleb128:
70 0 : return "sleb128";
71 74 : case dwarf::DW_EH_PE_udata4:
72 74 : return "udata4";
73 0 : case dwarf::DW_EH_PE_udata8:
74 0 : return "udata8";
75 0 : case dwarf::DW_EH_PE_sdata4:
76 0 : return "sdata4";
77 0 : case dwarf::DW_EH_PE_sdata8:
78 0 : return "sdata8";
79 0 : case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata4:
80 0 : return "pcrel udata4";
81 0 : case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4:
82 0 : return "pcrel sdata4";
83 0 : case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8:
84 0 : return "pcrel udata8";
85 0 : case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8:
86 0 : return "pcrel sdata8";
87 0 : case dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata4
88 : :
89 0 : return "indirect pcrel udata4";
90 50 : case dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
91 : :
92 50 : return "indirect pcrel sdata4";
93 5 : case dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8
94 : :
95 5 : return "indirect pcrel udata8";
96 6 : case dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8
97 : :
98 6 : return "indirect pcrel sdata8";
99 : }
100 :
101 0 : return "<unknown encoding>";
102 : }
103 :
104 : /// EmitEncodingByte - Emit a .byte 42 directive that corresponds to an
105 : /// encoding. If verbose assembly output is enabled, we output comments
106 : /// describing the encoding. Desc is an optional string saying what the
107 : /// encoding is specifying (e.g. "LSDA").
108 140340 : void AsmPrinter::EmitEncodingByte(unsigned Val, const char *Desc) const {
109 140340 : if (isVerbose()) {
110 864 : if (Desc)
111 864 : OutStreamer->AddComment(Twine(Desc) + " Encoding = " +
112 1728 : Twine(DecodeDWARFEncoding(Val)));
113 : else
114 0 : OutStreamer->AddComment(Twine("Encoding = ") + DecodeDWARFEncoding(Val));
115 : }
116 :
117 140340 : OutStreamer->EmitIntValue(Val, 1);
118 140340 : }
119 :
120 : /// GetSizeOfEncodedValue - Return the size of the encoding in bytes.
121 36723 : unsigned AsmPrinter::GetSizeOfEncodedValue(unsigned Encoding) const {
122 36723 : if (Encoding == dwarf::DW_EH_PE_omit)
123 : return 0;
124 :
125 36723 : switch (Encoding & 0x07) {
126 0 : default:
127 0 : llvm_unreachable("Invalid encoded value.");
128 113 : case dwarf::DW_EH_PE_absptr:
129 113 : return MF->getDataLayout().getPointerSize();
130 : case dwarf::DW_EH_PE_udata2:
131 : return 2;
132 35971 : case dwarf::DW_EH_PE_udata4:
133 35971 : return 4;
134 639 : case dwarf::DW_EH_PE_udata8:
135 639 : return 8;
136 : }
137 : }
138 :
139 36723 : void AsmPrinter::EmitTTypeReference(const GlobalValue *GV,
140 : unsigned Encoding) const {
141 36723 : if (GV) {
142 11573 : const TargetLoweringObjectFile &TLOF = getObjFileLowering();
143 :
144 : const MCExpr *Exp =
145 23146 : TLOF.getTTypeGlobalReference(GV, Encoding, TM, MMI, *OutStreamer);
146 11573 : OutStreamer->EmitValue(Exp, GetSizeOfEncodedValue(Encoding));
147 : } else
148 25150 : OutStreamer->EmitIntValue(0, GetSizeOfEncodedValue(Encoding));
149 36723 : }
150 :
151 51369 : void AsmPrinter::emitDwarfSymbolReference(const MCSymbol *Label,
152 : bool ForceOffset) const {
153 51369 : if (!ForceOffset) {
154 : // On COFF targets, we have to emit the special .secrel32 directive.
155 51362 : if (MAI->needsDwarfSectionOffsetDirective()) {
156 130 : OutStreamer->EmitCOFFSecRel32(Label, /*Offset=*/0);
157 130 : return;
158 : }
159 :
160 : // If the format uses relocations with dwarf, refer to the symbol directly.
161 51232 : if (MAI->doesDwarfUseRelocationsAcrossSections()) {
162 50827 : OutStreamer->EmitSymbolValue(Label, 4);
163 50828 : return;
164 : }
165 : }
166 :
167 : // Otherwise, emit it as a label difference from the start of the section.
168 411 : EmitLabelDifference(Label, Label->getSection().getBeginSymbol(), 4);
169 : }
170 :
171 2521 : void AsmPrinter::emitDwarfStringOffset(DwarfStringPoolEntry S) const {
172 2521 : if (MAI->doesDwarfUseRelocationsAcrossSections()) {
173 : assert(S.Symbol && "No symbol available");
174 914 : emitDwarfSymbolReference(S.Symbol);
175 914 : return;
176 : }
177 :
178 : // Just emit the offset directly; no need for symbol math.
179 1607 : emitInt32(S.Offset);
180 : }
181 :
182 0 : void AsmPrinter::EmitDwarfOffset(const MCSymbol *Label, uint64_t Offset) const {
183 0 : EmitLabelPlusOffset(Label, Offset, MAI->getCodePointerSize());
184 0 : }
185 :
186 : //===----------------------------------------------------------------------===//
187 : // Dwarf Lowering Routines
188 : //===----------------------------------------------------------------------===//
189 :
190 973881 : void AsmPrinter::emitCFIInstruction(const MCCFIInstruction &Inst) const {
191 973881 : switch (Inst.getOperation()) {
192 0 : default:
193 0 : llvm_unreachable("Unexpected instruction");
194 270600 : case MCCFIInstruction::OpDefCfaOffset:
195 270600 : OutStreamer->EmitCFIDefCfaOffset(Inst.getOffset());
196 270600 : break;
197 22126 : case MCCFIInstruction::OpAdjustCfaOffset:
198 22126 : OutStreamer->EmitCFIAdjustCfaOffset(Inst.getOffset());
199 22126 : break;
200 234194 : case MCCFIInstruction::OpDefCfa:
201 234194 : OutStreamer->EmitCFIDefCfa(Inst.getRegister(), Inst.getOffset());
202 234194 : break;
203 199217 : case MCCFIInstruction::OpDefCfaRegister:
204 199217 : OutStreamer->EmitCFIDefCfaRegister(Inst.getRegister());
205 199217 : break;
206 242175 : case MCCFIInstruction::OpOffset:
207 242175 : OutStreamer->EmitCFIOffset(Inst.getRegister(), Inst.getOffset());
208 242175 : break;
209 402 : case MCCFIInstruction::OpRegister:
210 402 : OutStreamer->EmitCFIRegister(Inst.getRegister(), Inst.getRegister2());
211 402 : break;
212 402 : case MCCFIInstruction::OpWindowSave:
213 402 : OutStreamer->EmitCFIWindowSave();
214 402 : break;
215 4 : case MCCFIInstruction::OpSameValue:
216 4 : OutStreamer->EmitCFISameValue(Inst.getRegister());
217 4 : break;
218 4759 : case MCCFIInstruction::OpGnuArgsSize:
219 4759 : OutStreamer->EmitCFIGnuArgsSize(Inst.getOffset());
220 4759 : break;
221 0 : case MCCFIInstruction::OpEscape:
222 0 : OutStreamer->EmitCFIEscape(Inst.getValues());
223 0 : break;
224 2 : case MCCFIInstruction::OpRestore:
225 2 : OutStreamer->EmitCFIRestore(Inst.getRegister());
226 2 : break;
227 : }
228 973881 : }
229 :
230 462508 : void AsmPrinter::emitDwarfDIE(const DIE &Die) const {
231 : // Emit the code (index) for the abbreviation.
232 462508 : if (isVerbose())
233 6708 : OutStreamer->AddComment("Abbrev [" + Twine(Die.getAbbrevNumber()) + "] 0x" +
234 3354 : Twine::utohexstr(Die.getOffset()) + ":0x" +
235 3354 : Twine::utohexstr(Die.getSize()) + " " +
236 6708 : dwarf::TagString(Die.getTag()));
237 462508 : EmitULEB128(Die.getAbbrevNumber());
238 :
239 : // Emit the DIE attribute values.
240 2052993 : for (const auto &V : Die.values()) {
241 1590484 : dwarf::Attribute Attr = V.getAttribute();
242 : assert(V.getForm() && "Too many attributes for DIE (check abbreviation)");
243 :
244 1590484 : if (isVerbose()) {
245 14268 : OutStreamer->AddComment(dwarf::AttributeString(Attr));
246 14268 : if (Attr == dwarf::DW_AT_accessibility)
247 39 : OutStreamer->AddComment(
248 78 : dwarf::AccessibilityString(V.getDIEInteger().getValue()));
249 : }
250 :
251 : // Emit an attribute using the defined form.
252 1590484 : V.EmitValue(this);
253 : }
254 :
255 : // Emit the DIE children if any.
256 : if (Die.hasChildren()) {
257 619698 : for (auto &Child : Die.children())
258 460849 : emitDwarfDIE(Child);
259 :
260 317698 : OutStreamer->AddComment("End Of Children Mark");
261 158849 : emitInt8(0);
262 : }
263 462509 : }
264 :
265 14246 : void AsmPrinter::emitDwarfAbbrev(const DIEAbbrev &Abbrev) const {
266 : // Emit the abbreviations code (base 1 index.)
267 14246 : EmitULEB128(Abbrev.getNumber(), "Abbreviation Code");
268 :
269 : // Emit the abbreviations data.
270 14247 : Abbrev.Emit(this);
271 14247 : }
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