1 //===- BitcodeAnalyzer.cpp - Internal BitcodeAnalyzer implementation ------===//
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 "llvm/Bitcode/BitcodeAnalyzer.h"
10 #include "llvm/Bitcode/BitcodeReader.h"
11 #include "llvm/Bitcode/LLVMBitCodes.h"
12 #include "llvm/Bitstream/BitCodes.h"
13 #include "llvm/Bitstream/BitstreamReader.h"
14 #include "llvm/Support/Format.h"
15 #include "llvm/Support/SHA1.h"
16 
17 using namespace llvm;
18 
19 static Error reportError(StringRef Message) {
20   return createStringError(std::errc::illegal_byte_sequence, Message.data());
21 }
22 
23 /// Return a symbolic block name if known, otherwise return null.
24 static Optional<const char *> GetBlockName(unsigned BlockID,
25                                            const BitstreamBlockInfo &BlockInfo,
26                                            CurStreamTypeType CurStreamType) {
27   // Standard blocks for all bitcode files.
28   if (BlockID < bitc::FIRST_APPLICATION_BLOCKID) {
29     if (BlockID == bitc::BLOCKINFO_BLOCK_ID)
30       return "BLOCKINFO_BLOCK";
31     return None;
32   }
33 
34   // Check to see if we have a blockinfo record for this block, with a name.
35   if (const BitstreamBlockInfo::BlockInfo *Info =
36           BlockInfo.getBlockInfo(BlockID)) {
37     if (!Info->Name.empty())
38       return Info->Name.c_str();
39   }
40 
41   if (CurStreamType != LLVMIRBitstream)
42     return None;
43 
44   switch (BlockID) {
45   default:
46     return None;
47   case bitc::OPERAND_BUNDLE_TAGS_BLOCK_ID:
48     return "OPERAND_BUNDLE_TAGS_BLOCK";
49   case bitc::MODULE_BLOCK_ID:
50     return "MODULE_BLOCK";
51   case bitc::PARAMATTR_BLOCK_ID:
52     return "PARAMATTR_BLOCK";
53   case bitc::PARAMATTR_GROUP_BLOCK_ID:
54     return "PARAMATTR_GROUP_BLOCK_ID";
55   case bitc::TYPE_BLOCK_ID_NEW:
56     return "TYPE_BLOCK_ID";
57   case bitc::CONSTANTS_BLOCK_ID:
58     return "CONSTANTS_BLOCK";
59   case bitc::FUNCTION_BLOCK_ID:
60     return "FUNCTION_BLOCK";
61   case bitc::IDENTIFICATION_BLOCK_ID:
62     return "IDENTIFICATION_BLOCK_ID";
63   case bitc::VALUE_SYMTAB_BLOCK_ID:
64     return "VALUE_SYMTAB";
65   case bitc::METADATA_BLOCK_ID:
66     return "METADATA_BLOCK";
67   case bitc::METADATA_KIND_BLOCK_ID:
68     return "METADATA_KIND_BLOCK";
69   case bitc::METADATA_ATTACHMENT_ID:
70     return "METADATA_ATTACHMENT_BLOCK";
71   case bitc::USELIST_BLOCK_ID:
72     return "USELIST_BLOCK_ID";
73   case bitc::GLOBALVAL_SUMMARY_BLOCK_ID:
74     return "GLOBALVAL_SUMMARY_BLOCK";
75   case bitc::FULL_LTO_GLOBALVAL_SUMMARY_BLOCK_ID:
76     return "FULL_LTO_GLOBALVAL_SUMMARY_BLOCK";
77   case bitc::MODULE_STRTAB_BLOCK_ID:
78     return "MODULE_STRTAB_BLOCK";
79   case bitc::STRTAB_BLOCK_ID:
80     return "STRTAB_BLOCK";
81   case bitc::SYMTAB_BLOCK_ID:
82     return "SYMTAB_BLOCK";
83   }
84 }
85 
86 /// Return a symbolic code name if known, otherwise return null.
87 static Optional<const char *> GetCodeName(unsigned CodeID, unsigned BlockID,
88                                           const BitstreamBlockInfo &BlockInfo,
89                                           CurStreamTypeType CurStreamType) {
90   // Standard blocks for all bitcode files.
91   if (BlockID < bitc::FIRST_APPLICATION_BLOCKID) {
92     if (BlockID == bitc::BLOCKINFO_BLOCK_ID) {
93       switch (CodeID) {
94       default:
95         return None;
96       case bitc::BLOCKINFO_CODE_SETBID:
97         return "SETBID";
98       case bitc::BLOCKINFO_CODE_BLOCKNAME:
99         return "BLOCKNAME";
100       case bitc::BLOCKINFO_CODE_SETRECORDNAME:
101         return "SETRECORDNAME";
102       }
103     }
104     return None;
105   }
106 
107   // Check to see if we have a blockinfo record for this record, with a name.
108   if (const BitstreamBlockInfo::BlockInfo *Info =
109           BlockInfo.getBlockInfo(BlockID)) {
110     for (unsigned i = 0, e = Info->RecordNames.size(); i != e; ++i)
111       if (Info->RecordNames[i].first == CodeID)
112         return Info->RecordNames[i].second.c_str();
113   }
114 
115   if (CurStreamType != LLVMIRBitstream)
116     return None;
117 
118 #define STRINGIFY_CODE(PREFIX, CODE)                                           \
119   case bitc::PREFIX##_##CODE:                                                  \
120     return #CODE;
121   switch (BlockID) {
122   default:
123     return None;
124   case bitc::MODULE_BLOCK_ID:
125     switch (CodeID) {
126     default:
127       return None;
128       STRINGIFY_CODE(MODULE_CODE, VERSION)
129       STRINGIFY_CODE(MODULE_CODE, TRIPLE)
130       STRINGIFY_CODE(MODULE_CODE, DATALAYOUT)
131       STRINGIFY_CODE(MODULE_CODE, ASM)
132       STRINGIFY_CODE(MODULE_CODE, SECTIONNAME)
133       STRINGIFY_CODE(MODULE_CODE, DEPLIB) // Deprecated, present in old bitcode
134       STRINGIFY_CODE(MODULE_CODE, GLOBALVAR)
135       STRINGIFY_CODE(MODULE_CODE, FUNCTION)
136       STRINGIFY_CODE(MODULE_CODE, ALIAS)
137       STRINGIFY_CODE(MODULE_CODE, GCNAME)
138       STRINGIFY_CODE(MODULE_CODE, VSTOFFSET)
139       STRINGIFY_CODE(MODULE_CODE, METADATA_VALUES_UNUSED)
140       STRINGIFY_CODE(MODULE_CODE, SOURCE_FILENAME)
141       STRINGIFY_CODE(MODULE_CODE, HASH)
142     }
143   case bitc::IDENTIFICATION_BLOCK_ID:
144     switch (CodeID) {
145     default:
146       return None;
147       STRINGIFY_CODE(IDENTIFICATION_CODE, STRING)
148       STRINGIFY_CODE(IDENTIFICATION_CODE, EPOCH)
149     }
150   case bitc::PARAMATTR_BLOCK_ID:
151     switch (CodeID) {
152     default:
153       return None;
154     // FIXME: Should these be different?
155     case bitc::PARAMATTR_CODE_ENTRY_OLD:
156       return "ENTRY";
157     case bitc::PARAMATTR_CODE_ENTRY:
158       return "ENTRY";
159     }
160   case bitc::PARAMATTR_GROUP_BLOCK_ID:
161     switch (CodeID) {
162     default:
163       return None;
164     case bitc::PARAMATTR_GRP_CODE_ENTRY:
165       return "ENTRY";
166     }
167   case bitc::TYPE_BLOCK_ID_NEW:
168     switch (CodeID) {
169     default:
170       return None;
171       STRINGIFY_CODE(TYPE_CODE, NUMENTRY)
172       STRINGIFY_CODE(TYPE_CODE, VOID)
173       STRINGIFY_CODE(TYPE_CODE, FLOAT)
174       STRINGIFY_CODE(TYPE_CODE, DOUBLE)
175       STRINGIFY_CODE(TYPE_CODE, LABEL)
176       STRINGIFY_CODE(TYPE_CODE, OPAQUE)
177       STRINGIFY_CODE(TYPE_CODE, INTEGER)
178       STRINGIFY_CODE(TYPE_CODE, POINTER)
179       STRINGIFY_CODE(TYPE_CODE, ARRAY)
180       STRINGIFY_CODE(TYPE_CODE, VECTOR)
181       STRINGIFY_CODE(TYPE_CODE, X86_FP80)
182       STRINGIFY_CODE(TYPE_CODE, FP128)
183       STRINGIFY_CODE(TYPE_CODE, PPC_FP128)
184       STRINGIFY_CODE(TYPE_CODE, METADATA)
185       STRINGIFY_CODE(TYPE_CODE, STRUCT_ANON)
186       STRINGIFY_CODE(TYPE_CODE, STRUCT_NAME)
187       STRINGIFY_CODE(TYPE_CODE, STRUCT_NAMED)
188       STRINGIFY_CODE(TYPE_CODE, FUNCTION)
189     }
190 
191   case bitc::CONSTANTS_BLOCK_ID:
192     switch (CodeID) {
193     default:
194       return None;
195       STRINGIFY_CODE(CST_CODE, SETTYPE)
196       STRINGIFY_CODE(CST_CODE, NULL)
197       STRINGIFY_CODE(CST_CODE, UNDEF)
198       STRINGIFY_CODE(CST_CODE, INTEGER)
199       STRINGIFY_CODE(CST_CODE, WIDE_INTEGER)
200       STRINGIFY_CODE(CST_CODE, FLOAT)
201       STRINGIFY_CODE(CST_CODE, AGGREGATE)
202       STRINGIFY_CODE(CST_CODE, STRING)
203       STRINGIFY_CODE(CST_CODE, CSTRING)
204       STRINGIFY_CODE(CST_CODE, CE_BINOP)
205       STRINGIFY_CODE(CST_CODE, CE_CAST)
206       STRINGIFY_CODE(CST_CODE, CE_GEP)
207       STRINGIFY_CODE(CST_CODE, CE_INBOUNDS_GEP)
208       STRINGIFY_CODE(CST_CODE, CE_SELECT)
209       STRINGIFY_CODE(CST_CODE, CE_EXTRACTELT)
210       STRINGIFY_CODE(CST_CODE, CE_INSERTELT)
211       STRINGIFY_CODE(CST_CODE, CE_SHUFFLEVEC)
212       STRINGIFY_CODE(CST_CODE, CE_CMP)
213       STRINGIFY_CODE(CST_CODE, INLINEASM)
214       STRINGIFY_CODE(CST_CODE, CE_SHUFVEC_EX)
215       STRINGIFY_CODE(CST_CODE, CE_UNOP)
216     case bitc::CST_CODE_BLOCKADDRESS:
217       return "CST_CODE_BLOCKADDRESS";
218       STRINGIFY_CODE(CST_CODE, DATA)
219     }
220   case bitc::FUNCTION_BLOCK_ID:
221     switch (CodeID) {
222     default:
223       return None;
224       STRINGIFY_CODE(FUNC_CODE, DECLAREBLOCKS)
225       STRINGIFY_CODE(FUNC_CODE, INST_BINOP)
226       STRINGIFY_CODE(FUNC_CODE, INST_CAST)
227       STRINGIFY_CODE(FUNC_CODE, INST_GEP_OLD)
228       STRINGIFY_CODE(FUNC_CODE, INST_INBOUNDS_GEP_OLD)
229       STRINGIFY_CODE(FUNC_CODE, INST_SELECT)
230       STRINGIFY_CODE(FUNC_CODE, INST_EXTRACTELT)
231       STRINGIFY_CODE(FUNC_CODE, INST_INSERTELT)
232       STRINGIFY_CODE(FUNC_CODE, INST_SHUFFLEVEC)
233       STRINGIFY_CODE(FUNC_CODE, INST_CMP)
234       STRINGIFY_CODE(FUNC_CODE, INST_RET)
235       STRINGIFY_CODE(FUNC_CODE, INST_BR)
236       STRINGIFY_CODE(FUNC_CODE, INST_SWITCH)
237       STRINGIFY_CODE(FUNC_CODE, INST_INVOKE)
238       STRINGIFY_CODE(FUNC_CODE, INST_UNOP)
239       STRINGIFY_CODE(FUNC_CODE, INST_UNREACHABLE)
240       STRINGIFY_CODE(FUNC_CODE, INST_CLEANUPRET)
241       STRINGIFY_CODE(FUNC_CODE, INST_CATCHRET)
242       STRINGIFY_CODE(FUNC_CODE, INST_CATCHPAD)
243       STRINGIFY_CODE(FUNC_CODE, INST_PHI)
244       STRINGIFY_CODE(FUNC_CODE, INST_ALLOCA)
245       STRINGIFY_CODE(FUNC_CODE, INST_LOAD)
246       STRINGIFY_CODE(FUNC_CODE, INST_VAARG)
247       STRINGIFY_CODE(FUNC_CODE, INST_STORE)
248       STRINGIFY_CODE(FUNC_CODE, INST_EXTRACTVAL)
249       STRINGIFY_CODE(FUNC_CODE, INST_INSERTVAL)
250       STRINGIFY_CODE(FUNC_CODE, INST_CMP2)
251       STRINGIFY_CODE(FUNC_CODE, INST_VSELECT)
252       STRINGIFY_CODE(FUNC_CODE, DEBUG_LOC_AGAIN)
253       STRINGIFY_CODE(FUNC_CODE, INST_CALL)
254       STRINGIFY_CODE(FUNC_CODE, DEBUG_LOC)
255       STRINGIFY_CODE(FUNC_CODE, INST_GEP)
256       STRINGIFY_CODE(FUNC_CODE, OPERAND_BUNDLE)
257       STRINGIFY_CODE(FUNC_CODE, INST_FENCE)
258       STRINGIFY_CODE(FUNC_CODE, INST_ATOMICRMW)
259       STRINGIFY_CODE(FUNC_CODE, INST_LOADATOMIC)
260       STRINGIFY_CODE(FUNC_CODE, INST_STOREATOMIC)
261       STRINGIFY_CODE(FUNC_CODE, INST_CMPXCHG)
262       STRINGIFY_CODE(FUNC_CODE, INST_CALLBR)
263     }
264   case bitc::VALUE_SYMTAB_BLOCK_ID:
265     switch (CodeID) {
266     default:
267       return None;
268       STRINGIFY_CODE(VST_CODE, ENTRY)
269       STRINGIFY_CODE(VST_CODE, BBENTRY)
270       STRINGIFY_CODE(VST_CODE, FNENTRY)
271       STRINGIFY_CODE(VST_CODE, COMBINED_ENTRY)
272     }
273   case bitc::MODULE_STRTAB_BLOCK_ID:
274     switch (CodeID) {
275     default:
276       return None;
277       STRINGIFY_CODE(MST_CODE, ENTRY)
278       STRINGIFY_CODE(MST_CODE, HASH)
279     }
280   case bitc::GLOBALVAL_SUMMARY_BLOCK_ID:
281   case bitc::FULL_LTO_GLOBALVAL_SUMMARY_BLOCK_ID:
282     switch (CodeID) {
283     default:
284       return None;
285       STRINGIFY_CODE(FS, PERMODULE)
286       STRINGIFY_CODE(FS, PERMODULE_PROFILE)
287       STRINGIFY_CODE(FS, PERMODULE_RELBF)
288       STRINGIFY_CODE(FS, PERMODULE_GLOBALVAR_INIT_REFS)
289       STRINGIFY_CODE(FS, PERMODULE_VTABLE_GLOBALVAR_INIT_REFS)
290       STRINGIFY_CODE(FS, COMBINED)
291       STRINGIFY_CODE(FS, COMBINED_PROFILE)
292       STRINGIFY_CODE(FS, COMBINED_GLOBALVAR_INIT_REFS)
293       STRINGIFY_CODE(FS, ALIAS)
294       STRINGIFY_CODE(FS, COMBINED_ALIAS)
295       STRINGIFY_CODE(FS, COMBINED_ORIGINAL_NAME)
296       STRINGIFY_CODE(FS, VERSION)
297       STRINGIFY_CODE(FS, FLAGS)
298       STRINGIFY_CODE(FS, TYPE_TESTS)
299       STRINGIFY_CODE(FS, TYPE_TEST_ASSUME_VCALLS)
300       STRINGIFY_CODE(FS, TYPE_CHECKED_LOAD_VCALLS)
301       STRINGIFY_CODE(FS, TYPE_TEST_ASSUME_CONST_VCALL)
302       STRINGIFY_CODE(FS, TYPE_CHECKED_LOAD_CONST_VCALL)
303       STRINGIFY_CODE(FS, VALUE_GUID)
304       STRINGIFY_CODE(FS, CFI_FUNCTION_DEFS)
305       STRINGIFY_CODE(FS, CFI_FUNCTION_DECLS)
306       STRINGIFY_CODE(FS, TYPE_ID)
307       STRINGIFY_CODE(FS, TYPE_ID_METADATA)
308       STRINGIFY_CODE(FS, BLOCK_COUNT)
309       STRINGIFY_CODE(FS, PARAM_ACCESS)
310     }
311   case bitc::METADATA_ATTACHMENT_ID:
312     switch (CodeID) {
313     default:
314       return None;
315       STRINGIFY_CODE(METADATA, ATTACHMENT)
316     }
317   case bitc::METADATA_BLOCK_ID:
318     switch (CodeID) {
319     default:
320       return None;
321       STRINGIFY_CODE(METADATA, STRING_OLD)
322       STRINGIFY_CODE(METADATA, VALUE)
323       STRINGIFY_CODE(METADATA, NODE)
324       STRINGIFY_CODE(METADATA, NAME)
325       STRINGIFY_CODE(METADATA, DISTINCT_NODE)
326       STRINGIFY_CODE(METADATA, KIND) // Older bitcode has it in a MODULE_BLOCK
327       STRINGIFY_CODE(METADATA, LOCATION)
328       STRINGIFY_CODE(METADATA, OLD_NODE)
329       STRINGIFY_CODE(METADATA, OLD_FN_NODE)
330       STRINGIFY_CODE(METADATA, NAMED_NODE)
331       STRINGIFY_CODE(METADATA, GENERIC_DEBUG)
332       STRINGIFY_CODE(METADATA, SUBRANGE)
333       STRINGIFY_CODE(METADATA, ENUMERATOR)
334       STRINGIFY_CODE(METADATA, BASIC_TYPE)
335       STRINGIFY_CODE(METADATA, FILE)
336       STRINGIFY_CODE(METADATA, DERIVED_TYPE)
337       STRINGIFY_CODE(METADATA, COMPOSITE_TYPE)
338       STRINGIFY_CODE(METADATA, SUBROUTINE_TYPE)
339       STRINGIFY_CODE(METADATA, COMPILE_UNIT)
340       STRINGIFY_CODE(METADATA, SUBPROGRAM)
341       STRINGIFY_CODE(METADATA, LEXICAL_BLOCK)
342       STRINGIFY_CODE(METADATA, LEXICAL_BLOCK_FILE)
343       STRINGIFY_CODE(METADATA, NAMESPACE)
344       STRINGIFY_CODE(METADATA, TEMPLATE_TYPE)
345       STRINGIFY_CODE(METADATA, TEMPLATE_VALUE)
346       STRINGIFY_CODE(METADATA, GLOBAL_VAR)
347       STRINGIFY_CODE(METADATA, LOCAL_VAR)
348       STRINGIFY_CODE(METADATA, EXPRESSION)
349       STRINGIFY_CODE(METADATA, OBJC_PROPERTY)
350       STRINGIFY_CODE(METADATA, IMPORTED_ENTITY)
351       STRINGIFY_CODE(METADATA, MODULE)
352       STRINGIFY_CODE(METADATA, MACRO)
353       STRINGIFY_CODE(METADATA, MACRO_FILE)
354       STRINGIFY_CODE(METADATA, STRINGS)
355       STRINGIFY_CODE(METADATA, GLOBAL_DECL_ATTACHMENT)
356       STRINGIFY_CODE(METADATA, GLOBAL_VAR_EXPR)
357       STRINGIFY_CODE(METADATA, INDEX_OFFSET)
358       STRINGIFY_CODE(METADATA, INDEX)
359     }
360   case bitc::METADATA_KIND_BLOCK_ID:
361     switch (CodeID) {
362     default:
363       return None;
364       STRINGIFY_CODE(METADATA, KIND)
365     }
366   case bitc::USELIST_BLOCK_ID:
367     switch (CodeID) {
368     default:
369       return None;
370     case bitc::USELIST_CODE_DEFAULT:
371       return "USELIST_CODE_DEFAULT";
372     case bitc::USELIST_CODE_BB:
373       return "USELIST_CODE_BB";
374     }
375 
376   case bitc::OPERAND_BUNDLE_TAGS_BLOCK_ID:
377     switch (CodeID) {
378     default:
379       return None;
380     case bitc::OPERAND_BUNDLE_TAG:
381       return "OPERAND_BUNDLE_TAG";
382     }
383   case bitc::STRTAB_BLOCK_ID:
384     switch (CodeID) {
385     default:
386       return None;
387     case bitc::STRTAB_BLOB:
388       return "BLOB";
389     }
390   case bitc::SYMTAB_BLOCK_ID:
391     switch (CodeID) {
392     default:
393       return None;
394     case bitc::SYMTAB_BLOB:
395       return "BLOB";
396     }
397   }
398 #undef STRINGIFY_CODE
399 }
400 
401 static void printSize(raw_ostream &OS, double Bits) {
402   OS << format("%.2f/%.2fB/%luW", Bits, Bits / 8, (unsigned long)(Bits / 32));
403 }
404 static void printSize(raw_ostream &OS, uint64_t Bits) {
405   OS << format("%lub/%.2fB/%luW", (unsigned long)Bits, (double)Bits / 8,
406                (unsigned long)(Bits / 32));
407 }
408 
409 static Expected<CurStreamTypeType> ReadSignature(BitstreamCursor &Stream) {
410   auto tryRead = [&Stream](char &Dest, size_t size) -> Error {
411     if (Expected<SimpleBitstreamCursor::word_t> MaybeWord = Stream.Read(size))
412       Dest = MaybeWord.get();
413     else
414       return MaybeWord.takeError();
415     return Error::success();
416   };
417 
418   char Signature[6];
419   if (Error Err = tryRead(Signature[0], 8))
420     return std::move(Err);
421   if (Error Err = tryRead(Signature[1], 8))
422     return std::move(Err);
423 
424   // Autodetect the file contents, if it is one we know.
425   if (Signature[0] == 'C' && Signature[1] == 'P') {
426     if (Error Err = tryRead(Signature[2], 8))
427       return std::move(Err);
428     if (Error Err = tryRead(Signature[3], 8))
429       return std::move(Err);
430     if (Signature[2] == 'C' && Signature[3] == 'H')
431       return ClangSerializedASTBitstream;
432   } else if (Signature[0] == 'D' && Signature[1] == 'I') {
433     if (Error Err = tryRead(Signature[2], 8))
434       return std::move(Err);
435     if (Error Err = tryRead(Signature[3], 8))
436       return std::move(Err);
437     if (Signature[2] == 'A' && Signature[3] == 'G')
438       return ClangSerializedDiagnosticsBitstream;
439   } else if (Signature[0] == 'R' && Signature[1] == 'M') {
440     if (Error Err = tryRead(Signature[2], 8))
441       return std::move(Err);
442     if (Error Err = tryRead(Signature[3], 8))
443       return std::move(Err);
444     if (Signature[2] == 'R' && Signature[3] == 'K')
445       return LLVMBitstreamRemarks;
446   } else {
447     if (Error Err = tryRead(Signature[2], 4))
448       return std::move(Err);
449     if (Error Err = tryRead(Signature[3], 4))
450       return std::move(Err);
451     if (Error Err = tryRead(Signature[4], 4))
452       return std::move(Err);
453     if (Error Err = tryRead(Signature[5], 4))
454       return std::move(Err);
455     if (Signature[0] == 'B' && Signature[1] == 'C' && Signature[2] == 0x0 &&
456         Signature[3] == 0xC && Signature[4] == 0xE && Signature[5] == 0xD)
457       return LLVMIRBitstream;
458   }
459   return UnknownBitstream;
460 }
461 
462 static Expected<CurStreamTypeType> analyzeHeader(Optional<BCDumpOptions> O,
463                                                  BitstreamCursor &Stream) {
464   ArrayRef<uint8_t> Bytes = Stream.getBitcodeBytes();
465   const unsigned char *BufPtr = (const unsigned char *)Bytes.data();
466   const unsigned char *EndBufPtr = BufPtr + Bytes.size();
467 
468   // If we have a wrapper header, parse it and ignore the non-bc file
469   // contents. The magic number is 0x0B17C0DE stored in little endian.
470   if (isBitcodeWrapper(BufPtr, EndBufPtr)) {
471     if (Bytes.size() < BWH_HeaderSize)
472       return reportError("Invalid bitcode wrapper header");
473 
474     if (O) {
475       unsigned Magic = support::endian::read32le(&BufPtr[BWH_MagicField]);
476       unsigned Version = support::endian::read32le(&BufPtr[BWH_VersionField]);
477       unsigned Offset = support::endian::read32le(&BufPtr[BWH_OffsetField]);
478       unsigned Size = support::endian::read32le(&BufPtr[BWH_SizeField]);
479       unsigned CPUType = support::endian::read32le(&BufPtr[BWH_CPUTypeField]);
480 
481       O->OS << "<BITCODE_WRAPPER_HEADER"
482             << " Magic=" << format_hex(Magic, 10)
483             << " Version=" << format_hex(Version, 10)
484             << " Offset=" << format_hex(Offset, 10)
485             << " Size=" << format_hex(Size, 10)
486             << " CPUType=" << format_hex(CPUType, 10) << "/>\n";
487     }
488 
489     if (SkipBitcodeWrapperHeader(BufPtr, EndBufPtr, true))
490       return reportError("Invalid bitcode wrapper header");
491   }
492 
493   // Use the cursor modified by skipping the wrapper header.
494   Stream = BitstreamCursor(ArrayRef<uint8_t>(BufPtr, EndBufPtr));
495 
496   return ReadSignature(Stream);
497 }
498 
499 static bool canDecodeBlob(unsigned Code, unsigned BlockID) {
500   return BlockID == bitc::METADATA_BLOCK_ID && Code == bitc::METADATA_STRINGS;
501 }
502 
503 Error BitcodeAnalyzer::decodeMetadataStringsBlob(StringRef Indent,
504                                                  ArrayRef<uint64_t> Record,
505                                                  StringRef Blob,
506                                                  raw_ostream &OS) {
507   if (Blob.empty())
508     return reportError("Cannot decode empty blob.");
509 
510   if (Record.size() != 2)
511     return reportError(
512         "Decoding metadata strings blob needs two record entries.");
513 
514   unsigned NumStrings = Record[0];
515   unsigned StringsOffset = Record[1];
516   OS << " num-strings = " << NumStrings << " {\n";
517 
518   StringRef Lengths = Blob.slice(0, StringsOffset);
519   SimpleBitstreamCursor R(Lengths);
520   StringRef Strings = Blob.drop_front(StringsOffset);
521   do {
522     if (R.AtEndOfStream())
523       return reportError("bad length");
524 
525     Expected<uint32_t> MaybeSize = R.ReadVBR(6);
526     if (!MaybeSize)
527       return MaybeSize.takeError();
528     uint32_t Size = MaybeSize.get();
529     if (Strings.size() < Size)
530       return reportError("truncated chars");
531 
532     OS << Indent << "    '";
533     OS.write_escaped(Strings.slice(0, Size), /*hex=*/true);
534     OS << "'\n";
535     Strings = Strings.drop_front(Size);
536   } while (--NumStrings);
537 
538   OS << Indent << "  }";
539   return Error::success();
540 }
541 
542 BitcodeAnalyzer::BitcodeAnalyzer(StringRef Buffer,
543                                  Optional<StringRef> BlockInfoBuffer)
544     : Stream(Buffer) {
545   if (BlockInfoBuffer)
546     BlockInfoStream.emplace(*BlockInfoBuffer);
547 }
548 
549 Error BitcodeAnalyzer::analyze(Optional<BCDumpOptions> O,
550                                Optional<StringRef> CheckHash) {
551   Expected<CurStreamTypeType> MaybeType = analyzeHeader(O, Stream);
552   if (!MaybeType)
553     return MaybeType.takeError();
554   else
555     CurStreamType = *MaybeType;
556 
557   Stream.setBlockInfo(&BlockInfo);
558 
559   // Read block info from BlockInfoStream, if specified.
560   // The block info must be a top-level block.
561   if (BlockInfoStream) {
562     BitstreamCursor BlockInfoCursor(*BlockInfoStream);
563     Expected<CurStreamTypeType> H = analyzeHeader(O, BlockInfoCursor);
564     if (!H)
565       return H.takeError();
566 
567     while (!BlockInfoCursor.AtEndOfStream()) {
568       Expected<unsigned> MaybeCode = BlockInfoCursor.ReadCode();
569       if (!MaybeCode)
570         return MaybeCode.takeError();
571       if (MaybeCode.get() != bitc::ENTER_SUBBLOCK)
572         return reportError("Invalid record at top-level in block info file");
573 
574       Expected<unsigned> MaybeBlockID = BlockInfoCursor.ReadSubBlockID();
575       if (!MaybeBlockID)
576         return MaybeBlockID.takeError();
577       if (MaybeBlockID.get() == bitc::BLOCKINFO_BLOCK_ID) {
578         Expected<Optional<BitstreamBlockInfo>> MaybeNewBlockInfo =
579             BlockInfoCursor.ReadBlockInfoBlock(/*ReadBlockInfoNames=*/true);
580         if (!MaybeNewBlockInfo)
581           return MaybeNewBlockInfo.takeError();
582         Optional<BitstreamBlockInfo> NewBlockInfo =
583             std::move(MaybeNewBlockInfo.get());
584         if (!NewBlockInfo)
585           return reportError("Malformed BlockInfoBlock in block info file");
586         BlockInfo = std::move(*NewBlockInfo);
587         break;
588       }
589 
590       if (Error Err = BlockInfoCursor.SkipBlock())
591         return Err;
592     }
593   }
594 
595   // Parse the top-level structure.  We only allow blocks at the top-level.
596   while (!Stream.AtEndOfStream()) {
597     Expected<unsigned> MaybeCode = Stream.ReadCode();
598     if (!MaybeCode)
599       return MaybeCode.takeError();
600     if (MaybeCode.get() != bitc::ENTER_SUBBLOCK)
601       return reportError("Invalid record at top-level");
602 
603     Expected<unsigned> MaybeBlockID = Stream.ReadSubBlockID();
604     if (!MaybeBlockID)
605       return MaybeBlockID.takeError();
606 
607     if (Error E = parseBlock(MaybeBlockID.get(), 0, O, CheckHash))
608       return E;
609     ++NumTopBlocks;
610   }
611 
612   return Error::success();
613 }
614 
615 void BitcodeAnalyzer::printStats(BCDumpOptions O,
616                                  Optional<StringRef> Filename) {
617   uint64_t BufferSizeBits = Stream.getBitcodeBytes().size() * CHAR_BIT;
618   // Print a summary of the read file.
619   O.OS << "Summary ";
620   if (Filename)
621     O.OS << "of " << Filename->data() << ":\n";
622   O.OS << "         Total size: ";
623   printSize(O.OS, BufferSizeBits);
624   O.OS << "\n";
625   O.OS << "        Stream type: ";
626   switch (CurStreamType) {
627   case UnknownBitstream:
628     O.OS << "unknown\n";
629     break;
630   case LLVMIRBitstream:
631     O.OS << "LLVM IR\n";
632     break;
633   case ClangSerializedASTBitstream:
634     O.OS << "Clang Serialized AST\n";
635     break;
636   case ClangSerializedDiagnosticsBitstream:
637     O.OS << "Clang Serialized Diagnostics\n";
638     break;
639   case LLVMBitstreamRemarks:
640     O.OS << "LLVM Remarks\n";
641     break;
642   }
643   O.OS << "  # Toplevel Blocks: " << NumTopBlocks << "\n";
644   O.OS << "\n";
645 
646   // Emit per-block stats.
647   O.OS << "Per-block Summary:\n";
648   for (std::map<unsigned, PerBlockIDStats>::iterator I = BlockIDStats.begin(),
649                                                      E = BlockIDStats.end();
650        I != E; ++I) {
651     O.OS << "  Block ID #" << I->first;
652     if (Optional<const char *> BlockName =
653             GetBlockName(I->first, BlockInfo, CurStreamType))
654       O.OS << " (" << *BlockName << ")";
655     O.OS << ":\n";
656 
657     const PerBlockIDStats &Stats = I->second;
658     O.OS << "      Num Instances: " << Stats.NumInstances << "\n";
659     O.OS << "         Total Size: ";
660     printSize(O.OS, Stats.NumBits);
661     O.OS << "\n";
662     double pct = (Stats.NumBits * 100.0) / BufferSizeBits;
663     O.OS << "    Percent of file: " << format("%2.4f%%", pct) << "\n";
664     if (Stats.NumInstances > 1) {
665       O.OS << "       Average Size: ";
666       printSize(O.OS, Stats.NumBits / (double)Stats.NumInstances);
667       O.OS << "\n";
668       O.OS << "  Tot/Avg SubBlocks: " << Stats.NumSubBlocks << "/"
669            << Stats.NumSubBlocks / (double)Stats.NumInstances << "\n";
670       O.OS << "    Tot/Avg Abbrevs: " << Stats.NumAbbrevs << "/"
671            << Stats.NumAbbrevs / (double)Stats.NumInstances << "\n";
672       O.OS << "    Tot/Avg Records: " << Stats.NumRecords << "/"
673            << Stats.NumRecords / (double)Stats.NumInstances << "\n";
674     } else {
675       O.OS << "      Num SubBlocks: " << Stats.NumSubBlocks << "\n";
676       O.OS << "        Num Abbrevs: " << Stats.NumAbbrevs << "\n";
677       O.OS << "        Num Records: " << Stats.NumRecords << "\n";
678     }
679     if (Stats.NumRecords) {
680       double pct = (Stats.NumAbbreviatedRecords * 100.0) / Stats.NumRecords;
681       O.OS << "    Percent Abbrevs: " << format("%2.4f%%", pct) << "\n";
682     }
683     O.OS << "\n";
684 
685     // Print a histogram of the codes we see.
686     if (O.Histogram && !Stats.CodeFreq.empty()) {
687       std::vector<std::pair<unsigned, unsigned>> FreqPairs; // <freq,code>
688       for (unsigned i = 0, e = Stats.CodeFreq.size(); i != e; ++i)
689         if (unsigned Freq = Stats.CodeFreq[i].NumInstances)
690           FreqPairs.push_back(std::make_pair(Freq, i));
691       llvm::stable_sort(FreqPairs);
692       std::reverse(FreqPairs.begin(), FreqPairs.end());
693 
694       O.OS << "\tRecord Histogram:\n";
695       O.OS << "\t\t  Count    # Bits     b/Rec   % Abv  Record Kind\n";
696       for (unsigned i = 0, e = FreqPairs.size(); i != e; ++i) {
697         const PerRecordStats &RecStats = Stats.CodeFreq[FreqPairs[i].second];
698 
699         O.OS << format("\t\t%7d %9lu", RecStats.NumInstances,
700                        (unsigned long)RecStats.TotalBits);
701 
702         if (RecStats.NumInstances > 1)
703           O.OS << format(" %9.1f",
704                          (double)RecStats.TotalBits / RecStats.NumInstances);
705         else
706           O.OS << "          ";
707 
708         if (RecStats.NumAbbrev)
709           O.OS << format(" %7.2f", (double)RecStats.NumAbbrev /
710                                        RecStats.NumInstances * 100);
711         else
712           O.OS << "        ";
713 
714         O.OS << "  ";
715         if (Optional<const char *> CodeName = GetCodeName(
716                 FreqPairs[i].second, I->first, BlockInfo, CurStreamType))
717           O.OS << *CodeName << "\n";
718         else
719           O.OS << "UnknownCode" << FreqPairs[i].second << "\n";
720       }
721       O.OS << "\n";
722     }
723   }
724 }
725 
726 Error BitcodeAnalyzer::parseBlock(unsigned BlockID, unsigned IndentLevel,
727                                   Optional<BCDumpOptions> O,
728                                   Optional<StringRef> CheckHash) {
729   std::string Indent(IndentLevel * 2, ' ');
730   uint64_t BlockBitStart = Stream.GetCurrentBitNo();
731 
732   // Get the statistics for this BlockID.
733   PerBlockIDStats &BlockStats = BlockIDStats[BlockID];
734 
735   BlockStats.NumInstances++;
736 
737   // BLOCKINFO is a special part of the stream.
738   bool DumpRecords = O.hasValue();
739   if (BlockID == bitc::BLOCKINFO_BLOCK_ID) {
740     if (O)
741       O->OS << Indent << "<BLOCKINFO_BLOCK/>\n";
742     Expected<Optional<BitstreamBlockInfo>> MaybeNewBlockInfo =
743         Stream.ReadBlockInfoBlock(/*ReadBlockInfoNames=*/true);
744     if (!MaybeNewBlockInfo)
745       return MaybeNewBlockInfo.takeError();
746     Optional<BitstreamBlockInfo> NewBlockInfo =
747         std::move(MaybeNewBlockInfo.get());
748     if (!NewBlockInfo)
749       return reportError("Malformed BlockInfoBlock");
750     BlockInfo = std::move(*NewBlockInfo);
751     if (Error Err = Stream.JumpToBit(BlockBitStart))
752       return Err;
753     // It's not really interesting to dump the contents of the blockinfo
754     // block.
755     DumpRecords = false;
756   }
757 
758   unsigned NumWords = 0;
759   if (Error Err = Stream.EnterSubBlock(BlockID, &NumWords))
760     return Err;
761 
762   // Keep it for later, when we see a MODULE_HASH record
763   uint64_t BlockEntryPos = Stream.getCurrentByteNo();
764 
765   Optional<const char *> BlockName = None;
766   if (DumpRecords) {
767     O->OS << Indent << "<";
768     if ((BlockName = GetBlockName(BlockID, BlockInfo, CurStreamType)))
769       O->OS << *BlockName;
770     else
771       O->OS << "UnknownBlock" << BlockID;
772 
773     if (!O->Symbolic && BlockName)
774       O->OS << " BlockID=" << BlockID;
775 
776     O->OS << " NumWords=" << NumWords
777           << " BlockCodeSize=" << Stream.getAbbrevIDWidth() << ">\n";
778   }
779 
780   SmallVector<uint64_t, 64> Record;
781 
782   // Keep the offset to the metadata index if seen.
783   uint64_t MetadataIndexOffset = 0;
784 
785   // Read all the records for this block.
786   while (1) {
787     if (Stream.AtEndOfStream())
788       return reportError("Premature end of bitstream");
789 
790     uint64_t RecordStartBit = Stream.GetCurrentBitNo();
791 
792     Expected<BitstreamEntry> MaybeEntry =
793         Stream.advance(BitstreamCursor::AF_DontAutoprocessAbbrevs);
794     if (!MaybeEntry)
795       return MaybeEntry.takeError();
796     BitstreamEntry Entry = MaybeEntry.get();
797 
798     switch (Entry.Kind) {
799     case BitstreamEntry::Error:
800       return reportError("malformed bitcode file");
801     case BitstreamEntry::EndBlock: {
802       uint64_t BlockBitEnd = Stream.GetCurrentBitNo();
803       BlockStats.NumBits += BlockBitEnd - BlockBitStart;
804       if (DumpRecords) {
805         O->OS << Indent << "</";
806         if (BlockName)
807           O->OS << *BlockName << ">\n";
808         else
809           O->OS << "UnknownBlock" << BlockID << ">\n";
810       }
811       return Error::success();
812     }
813 
814     case BitstreamEntry::SubBlock: {
815       uint64_t SubBlockBitStart = Stream.GetCurrentBitNo();
816       if (Error E = parseBlock(Entry.ID, IndentLevel + 1, O, CheckHash))
817         return E;
818       ++BlockStats.NumSubBlocks;
819       uint64_t SubBlockBitEnd = Stream.GetCurrentBitNo();
820 
821       // Don't include subblock sizes in the size of this block.
822       BlockBitStart += SubBlockBitEnd - SubBlockBitStart;
823       continue;
824     }
825     case BitstreamEntry::Record:
826       // The interesting case.
827       break;
828     }
829 
830     if (Entry.ID == bitc::DEFINE_ABBREV) {
831       if (Error Err = Stream.ReadAbbrevRecord())
832         return Err;
833       ++BlockStats.NumAbbrevs;
834       continue;
835     }
836 
837     Record.clear();
838 
839     ++BlockStats.NumRecords;
840 
841     StringRef Blob;
842     uint64_t CurrentRecordPos = Stream.GetCurrentBitNo();
843     Expected<unsigned> MaybeCode = Stream.readRecord(Entry.ID, Record, &Blob);
844     if (!MaybeCode)
845       return MaybeCode.takeError();
846     unsigned Code = MaybeCode.get();
847 
848     // Increment the # occurrences of this code.
849     if (BlockStats.CodeFreq.size() <= Code)
850       BlockStats.CodeFreq.resize(Code + 1);
851     BlockStats.CodeFreq[Code].NumInstances++;
852     BlockStats.CodeFreq[Code].TotalBits +=
853         Stream.GetCurrentBitNo() - RecordStartBit;
854     if (Entry.ID != bitc::UNABBREV_RECORD) {
855       BlockStats.CodeFreq[Code].NumAbbrev++;
856       ++BlockStats.NumAbbreviatedRecords;
857     }
858 
859     if (DumpRecords) {
860       O->OS << Indent << "  <";
861       Optional<const char *> CodeName =
862           GetCodeName(Code, BlockID, BlockInfo, CurStreamType);
863       if (CodeName)
864         O->OS << *CodeName;
865       else
866         O->OS << "UnknownCode" << Code;
867       if (!O->Symbolic && CodeName)
868         O->OS << " codeid=" << Code;
869       const BitCodeAbbrev *Abbv = nullptr;
870       if (Entry.ID != bitc::UNABBREV_RECORD) {
871         Abbv = Stream.getAbbrev(Entry.ID);
872         O->OS << " abbrevid=" << Entry.ID;
873       }
874 
875       for (unsigned i = 0, e = Record.size(); i != e; ++i)
876         O->OS << " op" << i << "=" << (int64_t)Record[i];
877 
878       // If we found a metadata index, let's verify that we had an offset
879       // before and validate its forward reference offset was correct!
880       if (BlockID == bitc::METADATA_BLOCK_ID) {
881         if (Code == bitc::METADATA_INDEX_OFFSET) {
882           if (Record.size() != 2)
883             O->OS << "(Invalid record)";
884           else {
885             auto Offset = Record[0] + (Record[1] << 32);
886             MetadataIndexOffset = Stream.GetCurrentBitNo() + Offset;
887           }
888         }
889         if (Code == bitc::METADATA_INDEX) {
890           O->OS << " (offset ";
891           if (MetadataIndexOffset == RecordStartBit)
892             O->OS << "match)";
893           else
894             O->OS << "mismatch: " << MetadataIndexOffset << " vs "
895                   << RecordStartBit << ")";
896         }
897       }
898 
899       // If we found a module hash, let's verify that it matches!
900       if (BlockID == bitc::MODULE_BLOCK_ID && Code == bitc::MODULE_CODE_HASH &&
901           CheckHash.hasValue()) {
902         if (Record.size() != 5)
903           O->OS << " (invalid)";
904         else {
905           // Recompute the hash and compare it to the one in the bitcode
906           SHA1 Hasher;
907           StringRef Hash;
908           Hasher.update(*CheckHash);
909           {
910             int BlockSize = (CurrentRecordPos / 8) - BlockEntryPos;
911             auto Ptr = Stream.getPointerToByte(BlockEntryPos, BlockSize);
912             Hasher.update(ArrayRef<uint8_t>(Ptr, BlockSize));
913             Hash = Hasher.result();
914           }
915           std::array<char, 20> RecordedHash;
916           int Pos = 0;
917           for (auto &Val : Record) {
918             assert(!(Val >> 32) && "Unexpected high bits set");
919             support::endian::write32be(&RecordedHash[Pos], Val);
920             Pos += 4;
921           }
922           if (Hash == StringRef(RecordedHash.data(), RecordedHash.size()))
923             O->OS << " (match)";
924           else
925             O->OS << " (!mismatch!)";
926         }
927       }
928 
929       O->OS << "/>";
930 
931       if (Abbv) {
932         for (unsigned i = 1, e = Abbv->getNumOperandInfos(); i != e; ++i) {
933           const BitCodeAbbrevOp &Op = Abbv->getOperandInfo(i);
934           if (!Op.isEncoding() || Op.getEncoding() != BitCodeAbbrevOp::Array)
935             continue;
936           assert(i + 2 == e && "Array op not second to last");
937           std::string Str;
938           bool ArrayIsPrintable = true;
939           for (unsigned j = i - 1, je = Record.size(); j != je; ++j) {
940             if (!isPrint(static_cast<unsigned char>(Record[j]))) {
941               ArrayIsPrintable = false;
942               break;
943             }
944             Str += (char)Record[j];
945           }
946           if (ArrayIsPrintable)
947             O->OS << " record string = '" << Str << "'";
948           break;
949         }
950       }
951 
952       if (Blob.data()) {
953         if (canDecodeBlob(Code, BlockID)) {
954           if (Error E = decodeMetadataStringsBlob(Indent, Record, Blob, O->OS))
955             return E;
956         } else {
957           O->OS << " blob data = ";
958           if (O->ShowBinaryBlobs) {
959             O->OS << "'";
960             O->OS.write_escaped(Blob, /*hex=*/true) << "'";
961           } else {
962             bool BlobIsPrintable = true;
963             for (unsigned i = 0, e = Blob.size(); i != e; ++i)
964               if (!isPrint(static_cast<unsigned char>(Blob[i]))) {
965                 BlobIsPrintable = false;
966                 break;
967               }
968 
969             if (BlobIsPrintable)
970               O->OS << "'" << Blob << "'";
971             else
972               O->OS << "unprintable, " << Blob.size() << " bytes.";
973           }
974         }
975       }
976 
977       O->OS << "\n";
978     }
979 
980     // Make sure that we can skip the current record.
981     if (Error Err = Stream.JumpToBit(CurrentRecordPos))
982       return Err;
983     if (Expected<unsigned> Skipped = Stream.skipRecord(Entry.ID))
984       ; // Do nothing.
985     else
986       return Skipped.takeError();
987   }
988 }
989 
990