MCObjectFileInfo.h revision 360784 
1//===-- llvm/MC/MCObjectFileInfo.h - Object File Info -----------*- 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// This file describes common object file formats.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_MC_MCOBJECTFILEINFO_H
14#define LLVM_MC_MCOBJECTFILEINFO_H
15
16#include "llvm/ADT/DenseMap.h"
17#include "llvm/ADT/Triple.h"
18#include "llvm/MC/MCSymbol.h"
19#include "llvm/Support/CodeGen.h"
20#include "llvm/Support/VersionTuple.h"
21
22namespace llvm {
23class MCContext;
24class MCSection;
25
26class MCObjectFileInfo {
27protected:
28  /// True if .comm supports alignment.  This is a hack for as long as we
29  /// support 10.4 Tiger, whose assembler doesn't support alignment on comm.
30  bool CommDirectiveSupportsAlignment = false;
31
32  /// True if target object file supports a weak_definition of constant 0 for an
33  /// omitted EH frame.
34  bool SupportsWeakOmittedEHFrame = false;
35
36  /// True if the target object file supports emitting a compact unwind section
37  /// without an associated EH frame section.
38  bool SupportsCompactUnwindWithoutEHFrame = false;
39
40  /// OmitDwarfIfHaveCompactUnwind - True if the target object file
41  /// supports having some functions with compact unwind and other with
42  /// dwarf unwind.
43  bool OmitDwarfIfHaveCompactUnwind = false;
44
45  /// FDE CFI encoding. Controls the encoding of the begin label in the
46  /// .eh_frame section. Unlike the LSDA encoding, personality encoding, and
47  /// type encodings, this is something that the assembler just "knows" about
48  /// its target
49  unsigned FDECFIEncoding = 0;
50
51  /// Compact unwind encoding indicating that we should emit only an EH frame.
52  unsigned CompactUnwindDwarfEHFrameOnly = 0;
53
54  /// Section directive for standard text.
55  MCSection *TextSection = nullptr;
56
57  /// Section directive for standard data.
58  MCSection *DataSection = nullptr;
59
60  /// Section that is default initialized to zero.
61  MCSection *BSSSection = nullptr;
62
63  /// Section that is readonly and can contain arbitrary initialized data.
64  /// Targets are not required to have a readonly section. If they don't,
65  /// various bits of code will fall back to using the data section for
66  /// constants.
67  MCSection *ReadOnlySection = nullptr;
68
69  /// If exception handling is supported by the target, this is the section the
70  /// Language Specific Data Area information is emitted to.
71  MCSection *LSDASection = nullptr;
72
73  /// If exception handling is supported by the target and the target can
74  /// support a compact representation of the CIE and FDE, this is the section
75  /// to emit them into.
76  MCSection *CompactUnwindSection = nullptr;
77
78  // Dwarf sections for debug info.  If a target supports debug info, these must
79  // be set.
80  MCSection *DwarfAbbrevSection = nullptr;
81  MCSection *DwarfInfoSection = nullptr;
82  MCSection *DwarfLineSection = nullptr;
83  MCSection *DwarfLineStrSection = nullptr;
84  MCSection *DwarfFrameSection = nullptr;
85  MCSection *DwarfPubTypesSection = nullptr;
86  const MCSection *DwarfDebugInlineSection = nullptr;
87  MCSection *DwarfStrSection = nullptr;
88  MCSection *DwarfLocSection = nullptr;
89  MCSection *DwarfARangesSection = nullptr;
90  MCSection *DwarfRangesSection = nullptr;
91  MCSection *DwarfMacinfoSection = nullptr;
92  // The pubnames section is no longer generated by default.  The generation
93  // can be enabled by a compiler flag.
94  MCSection *DwarfPubNamesSection = nullptr;
95
96  /// Accelerator table sections. DwarfDebugNamesSection is the DWARF v5
97  /// accelerator table, while DwarfAccelNamesSection, DwarfAccelObjCSection,
98  /// DwarfAccelNamespaceSection, DwarfAccelTypesSection are pre-DWARF v5
99  /// extensions.
100  MCSection *DwarfDebugNamesSection = nullptr;
101  MCSection *DwarfAccelNamesSection = nullptr;
102  MCSection *DwarfAccelObjCSection = nullptr;
103  MCSection *DwarfAccelNamespaceSection = nullptr;
104  MCSection *DwarfAccelTypesSection = nullptr;
105
106  // These are used for the Fission separate debug information files.
107  MCSection *DwarfInfoDWOSection = nullptr;
108  MCSection *DwarfTypesDWOSection = nullptr;
109  MCSection *DwarfAbbrevDWOSection = nullptr;
110  MCSection *DwarfStrDWOSection = nullptr;
111  MCSection *DwarfLineDWOSection = nullptr;
112  MCSection *DwarfLocDWOSection = nullptr;
113  MCSection *DwarfStrOffDWOSection = nullptr;
114  MCSection *DwarfMacinfoDWOSection = nullptr;
115
116  /// The DWARF v5 string offset and address table sections.
117  MCSection *DwarfStrOffSection = nullptr;
118  MCSection *DwarfAddrSection = nullptr;
119  /// The DWARF v5 range list section.
120  MCSection *DwarfRnglistsSection = nullptr;
121  /// The DWARF v5 locations list section.
122  MCSection *DwarfLoclistsSection = nullptr;
123
124  /// The DWARF v5 range and location list sections for fission.
125  MCSection *DwarfRnglistsDWOSection = nullptr;
126  MCSection *DwarfLoclistsDWOSection = nullptr;
127
128  // These are for Fission DWP files.
129  MCSection *DwarfCUIndexSection = nullptr;
130  MCSection *DwarfTUIndexSection = nullptr;
131
132  /// Section for newer gnu pubnames.
133  MCSection *DwarfGnuPubNamesSection = nullptr;
134  /// Section for newer gnu pubtypes.
135  MCSection *DwarfGnuPubTypesSection = nullptr;
136
137  // Section for Swift AST
138  MCSection *DwarfSwiftASTSection = nullptr;
139
140  MCSection *COFFDebugSymbolsSection = nullptr;
141  MCSection *COFFDebugTypesSection = nullptr;
142  MCSection *COFFGlobalTypeHashesSection = nullptr;
143
144  /// Extra TLS Variable Data section.
145  ///
146  /// If the target needs to put additional information for a TLS variable,
147  /// it'll go here.
148  MCSection *TLSExtraDataSection = nullptr;
149
150  /// Section directive for Thread Local data. ELF, MachO, COFF, and Wasm.
151  MCSection *TLSDataSection = nullptr; // Defaults to ".tdata".
152
153  /// Section directive for Thread Local uninitialized data.
154  ///
155  /// Null if this target doesn't support a BSS section. ELF and MachO only.
156  MCSection *TLSBSSSection = nullptr; // Defaults to ".tbss".
157
158  /// StackMap section.
159  MCSection *StackMapSection = nullptr;
160
161  /// FaultMap section.
162  MCSection *FaultMapSection = nullptr;
163
164  /// Remarks section.
165  MCSection *RemarksSection = nullptr;
166
167  /// EH frame section.
168  ///
169  /// It is initialized on demand so it can be overwritten (with uniquing).
170  MCSection *EHFrameSection = nullptr;
171
172  /// Section containing metadata on function stack sizes.
173  MCSection *StackSizesSection = nullptr;
174  mutable DenseMap<const MCSymbol *, unsigned> StackSizesUniquing;
175
176  // ELF specific sections.
177  MCSection *DataRelROSection = nullptr;
178  MCSection *MergeableConst4Section = nullptr;
179  MCSection *MergeableConst8Section = nullptr;
180  MCSection *MergeableConst16Section = nullptr;
181  MCSection *MergeableConst32Section = nullptr;
182
183  // MachO specific sections.
184
185  /// Section for thread local structure information.
186  ///
187  /// Contains the source code name of the variable, visibility and a pointer to
188  /// the initial value (.tdata or .tbss).
189  MCSection *TLSTLVSection = nullptr; // Defaults to ".tlv".
190
191  /// Section for thread local data initialization functions.
192   // Defaults to ".thread_init_func".
193  const MCSection *TLSThreadInitSection = nullptr;
194
195  MCSection *CStringSection = nullptr;
196  MCSection *UStringSection = nullptr;
197  MCSection *TextCoalSection = nullptr;
198  MCSection *ConstTextCoalSection = nullptr;
199  MCSection *ConstDataSection = nullptr;
200  MCSection *DataCoalSection = nullptr;
201  MCSection *ConstDataCoalSection = nullptr;
202  MCSection *DataCommonSection = nullptr;
203  MCSection *DataBSSSection = nullptr;
204  MCSection *FourByteConstantSection = nullptr;
205  MCSection *EightByteConstantSection = nullptr;
206  MCSection *SixteenByteConstantSection = nullptr;
207  MCSection *LazySymbolPointerSection = nullptr;
208  MCSection *NonLazySymbolPointerSection = nullptr;
209  MCSection *ThreadLocalPointerSection = nullptr;
210
211  /// COFF specific sections.
212  MCSection *DrectveSection = nullptr;
213  MCSection *PDataSection = nullptr;
214  MCSection *XDataSection = nullptr;
215  MCSection *SXDataSection = nullptr;
216  MCSection *GFIDsSection = nullptr;
217  MCSection *GLJMPSection = nullptr;
218
219public:
220  void InitMCObjectFileInfo(const Triple &TT, bool PIC, MCContext &ctx,
221                            bool LargeCodeModel = false);
222
223  bool getSupportsWeakOmittedEHFrame() const {
224    return SupportsWeakOmittedEHFrame;
225  }
226  bool getSupportsCompactUnwindWithoutEHFrame() const {
227    return SupportsCompactUnwindWithoutEHFrame;
228  }
229  bool getOmitDwarfIfHaveCompactUnwind() const {
230    return OmitDwarfIfHaveCompactUnwind;
231  }
232
233  bool getCommDirectiveSupportsAlignment() const {
234    return CommDirectiveSupportsAlignment;
235  }
236
237  unsigned getFDEEncoding() const { return FDECFIEncoding; }
238
239  unsigned getCompactUnwindDwarfEHFrameOnly() const {
240    return CompactUnwindDwarfEHFrameOnly;
241  }
242
243  MCSection *getTextSection() const { return TextSection; }
244  MCSection *getDataSection() const { return DataSection; }
245  MCSection *getBSSSection() const { return BSSSection; }
246  MCSection *getReadOnlySection() const { return ReadOnlySection; }
247  MCSection *getLSDASection() const { return LSDASection; }
248  MCSection *getCompactUnwindSection() const { return CompactUnwindSection; }
249  MCSection *getDwarfAbbrevSection() const { return DwarfAbbrevSection; }
250  MCSection *getDwarfInfoSection() const { return DwarfInfoSection; }
251  MCSection *getDwarfInfoSection(uint64_t Hash) const {
252    return getDwarfComdatSection(".debug_info", Hash);
253  }
254  MCSection *getDwarfLineSection() const { return DwarfLineSection; }
255  MCSection *getDwarfLineStrSection() const { return DwarfLineStrSection; }
256  MCSection *getDwarfFrameSection() const { return DwarfFrameSection; }
257  MCSection *getDwarfPubNamesSection() const { return DwarfPubNamesSection; }
258  MCSection *getDwarfPubTypesSection() const { return DwarfPubTypesSection; }
259  MCSection *getDwarfGnuPubNamesSection() const {
260    return DwarfGnuPubNamesSection;
261  }
262  MCSection *getDwarfGnuPubTypesSection() const {
263    return DwarfGnuPubTypesSection;
264  }
265  const MCSection *getDwarfDebugInlineSection() const {
266    return DwarfDebugInlineSection;
267  }
268  MCSection *getDwarfStrSection() const { return DwarfStrSection; }
269  MCSection *getDwarfLocSection() const { return DwarfLocSection; }
270  MCSection *getDwarfARangesSection() const { return DwarfARangesSection; }
271  MCSection *getDwarfRangesSection() const { return DwarfRangesSection; }
272  MCSection *getDwarfRnglistsSection() const { return DwarfRnglistsSection; }
273  MCSection *getDwarfLoclistsSection() const { return DwarfLoclistsSection; }
274  MCSection *getDwarfMacinfoSection() const { return DwarfMacinfoSection; }
275
276  MCSection *getDwarfDebugNamesSection() const {
277    return DwarfDebugNamesSection;
278  }
279  MCSection *getDwarfAccelNamesSection() const {
280    return DwarfAccelNamesSection;
281  }
282  MCSection *getDwarfAccelObjCSection() const { return DwarfAccelObjCSection; }
283  MCSection *getDwarfAccelNamespaceSection() const {
284    return DwarfAccelNamespaceSection;
285  }
286  MCSection *getDwarfAccelTypesSection() const {
287    return DwarfAccelTypesSection;
288  }
289  MCSection *getDwarfInfoDWOSection() const { return DwarfInfoDWOSection; }
290  MCSection *getDwarfTypesSection(uint64_t Hash) const {
291    return getDwarfComdatSection(".debug_types", Hash);
292  }
293  MCSection *getDwarfTypesDWOSection() const { return DwarfTypesDWOSection; }
294  MCSection *getDwarfAbbrevDWOSection() const { return DwarfAbbrevDWOSection; }
295  MCSection *getDwarfStrDWOSection() const { return DwarfStrDWOSection; }
296  MCSection *getDwarfLineDWOSection() const { return DwarfLineDWOSection; }
297  MCSection *getDwarfLocDWOSection() const { return DwarfLocDWOSection; }
298  MCSection *getDwarfStrOffDWOSection() const { return DwarfStrOffDWOSection; }
299  MCSection *getDwarfStrOffSection() const { return DwarfStrOffSection; }
300  MCSection *getDwarfAddrSection() const { return DwarfAddrSection; }
301  MCSection *getDwarfRnglistsDWOSection() const {
302    return DwarfRnglistsDWOSection;
303  }
304  MCSection *getDwarfLoclistsDWOSection() const {
305    return DwarfLoclistsDWOSection;
306  }
307  MCSection *getDwarfMacinfoDWOSection() const {
308    return DwarfMacinfoDWOSection;
309  }
310  MCSection *getDwarfCUIndexSection() const { return DwarfCUIndexSection; }
311  MCSection *getDwarfTUIndexSection() const { return DwarfTUIndexSection; }
312  MCSection *getDwarfSwiftASTSection() const { return DwarfSwiftASTSection; }
313
314  MCSection *getCOFFDebugSymbolsSection() const {
315    return COFFDebugSymbolsSection;
316  }
317  MCSection *getCOFFDebugTypesSection() const {
318    return COFFDebugTypesSection;
319  }
320  MCSection *getCOFFGlobalTypeHashesSection() const {
321    return COFFGlobalTypeHashesSection;
322  }
323
324  MCSection *getTLSExtraDataSection() const { return TLSExtraDataSection; }
325  const MCSection *getTLSDataSection() const { return TLSDataSection; }
326  MCSection *getTLSBSSSection() const { return TLSBSSSection; }
327
328  MCSection *getStackMapSection() const { return StackMapSection; }
329  MCSection *getFaultMapSection() const { return FaultMapSection; }
330  MCSection *getRemarksSection() const { return RemarksSection; }
331
332  MCSection *getStackSizesSection(const MCSection &TextSec) const;
333
334  // ELF specific sections.
335  MCSection *getDataRelROSection() const { return DataRelROSection; }
336  const MCSection *getMergeableConst4Section() const {
337    return MergeableConst4Section;
338  }
339  const MCSection *getMergeableConst8Section() const {
340    return MergeableConst8Section;
341  }
342  const MCSection *getMergeableConst16Section() const {
343    return MergeableConst16Section;
344  }
345  const MCSection *getMergeableConst32Section() const {
346    return MergeableConst32Section;
347  }
348
349  // MachO specific sections.
350  const MCSection *getTLSTLVSection() const { return TLSTLVSection; }
351  const MCSection *getTLSThreadInitSection() const {
352    return TLSThreadInitSection;
353  }
354  const MCSection *getCStringSection() const { return CStringSection; }
355  const MCSection *getUStringSection() const { return UStringSection; }
356  MCSection *getTextCoalSection() const { return TextCoalSection; }
357  const MCSection *getConstTextCoalSection() const {
358    return ConstTextCoalSection;
359  }
360  const MCSection *getConstDataSection() const { return ConstDataSection; }
361  const MCSection *getDataCoalSection() const { return DataCoalSection; }
362  const MCSection *getConstDataCoalSection() const {
363    return ConstDataCoalSection;
364  }
365  const MCSection *getDataCommonSection() const { return DataCommonSection; }
366  MCSection *getDataBSSSection() const { return DataBSSSection; }
367  const MCSection *getFourByteConstantSection() const {
368    return FourByteConstantSection;
369  }
370  const MCSection *getEightByteConstantSection() const {
371    return EightByteConstantSection;
372  }
373  const MCSection *getSixteenByteConstantSection() const {
374    return SixteenByteConstantSection;
375  }
376  MCSection *getLazySymbolPointerSection() const {
377    return LazySymbolPointerSection;
378  }
379  MCSection *getNonLazySymbolPointerSection() const {
380    return NonLazySymbolPointerSection;
381  }
382  MCSection *getThreadLocalPointerSection() const {
383    return ThreadLocalPointerSection;
384  }
385
386  // COFF specific sections.
387  MCSection *getDrectveSection() const { return DrectveSection; }
388  MCSection *getPDataSection() const { return PDataSection; }
389  MCSection *getXDataSection() const { return XDataSection; }
390  MCSection *getSXDataSection() const { return SXDataSection; }
391  MCSection *getGFIDsSection() const { return GFIDsSection; }
392  MCSection *getGLJMPSection() const { return GLJMPSection; }
393
394  MCSection *getEHFrameSection() {
395    return EHFrameSection;
396  }
397
398  enum Environment { IsMachO, IsELF, IsCOFF, IsWasm, IsXCOFF };
399  Environment getObjectFileType() const { return Env; }
400
401  bool isPositionIndependent() const { return PositionIndependent; }
402
403private:
404  Environment Env;
405  bool PositionIndependent = false;
406  MCContext *Ctx = nullptr;
407  Triple TT;
408  VersionTuple SDKVersion;
409
410  void initMachOMCObjectFileInfo(const Triple &T);
411  void initELFMCObjectFileInfo(const Triple &T, bool Large);
412  void initCOFFMCObjectFileInfo(const Triple &T);
413  void initWasmMCObjectFileInfo(const Triple &T);
414  void initXCOFFMCObjectFileInfo(const Triple &T);
415  MCSection *getDwarfComdatSection(const char *Name, uint64_t Hash) const;
416
417public:
418  const Triple &getTargetTriple() const { return TT; }
419
420  void setSDKVersion(const VersionTuple &TheSDKVersion) {
421    SDKVersion = TheSDKVersion;
422  }
423
424  const VersionTuple &getSDKVersion() const { return SDKVersion; }
425};
426
427} // end namespace llvm
428
429#endif
430