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1 //===-- COFFDump.cpp - COFF-specific dumper ---------------------*- C++ -*-===//
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 /// \file
11 /// \brief This file implements the COFF-specific dumper for llvm-objdump.
12 /// It outputs the Win64 EH data structures as plain text.
13 /// The encoding of the unwind codes is described in MSDN:
14 /// http://msdn.microsoft.com/en-us/library/ck9asaa9.aspx
15 ///
16 //===----------------------------------------------------------------------===//
17 
18 #include "llvm-objdump.h"
19 #include "llvm/Object/COFF.h"
20 #include "llvm/Object/ObjectFile.h"
21 #include "llvm/Support/Format.h"
22 #include "llvm/Support/SourceMgr.h"
23 #include "llvm/Support/Win64EH.h"
24 #include "llvm/Support/raw_ostream.h"
25 #include <algorithm>
26 #include <cstring>
27 #include <system_error>
28 
29 using namespace llvm;
30 using namespace object;
31 using namespace llvm::Win64EH;
32 
33 // Returns the name of the unwind code.
getUnwindCodeTypeName(uint8_t Code)34 static StringRef getUnwindCodeTypeName(uint8_t Code) {
35   switch(Code) {
36   default: llvm_unreachable("Invalid unwind code");
37   case UOP_PushNonVol: return "UOP_PushNonVol";
38   case UOP_AllocLarge: return "UOP_AllocLarge";
39   case UOP_AllocSmall: return "UOP_AllocSmall";
40   case UOP_SetFPReg: return "UOP_SetFPReg";
41   case UOP_SaveNonVol: return "UOP_SaveNonVol";
42   case UOP_SaveNonVolBig: return "UOP_SaveNonVolBig";
43   case UOP_SaveXMM128: return "UOP_SaveXMM128";
44   case UOP_SaveXMM128Big: return "UOP_SaveXMM128Big";
45   case UOP_PushMachFrame: return "UOP_PushMachFrame";
46   }
47 }
48 
49 // Returns the name of a referenced register.
getUnwindRegisterName(uint8_t Reg)50 static StringRef getUnwindRegisterName(uint8_t Reg) {
51   switch(Reg) {
52   default: llvm_unreachable("Invalid register");
53   case 0: return "RAX";
54   case 1: return "RCX";
55   case 2: return "RDX";
56   case 3: return "RBX";
57   case 4: return "RSP";
58   case 5: return "RBP";
59   case 6: return "RSI";
60   case 7: return "RDI";
61   case 8: return "R8";
62   case 9: return "R9";
63   case 10: return "R10";
64   case 11: return "R11";
65   case 12: return "R12";
66   case 13: return "R13";
67   case 14: return "R14";
68   case 15: return "R15";
69   }
70 }
71 
72 // Calculates the number of array slots required for the unwind code.
getNumUsedSlots(const UnwindCode & UnwindCode)73 static unsigned getNumUsedSlots(const UnwindCode &UnwindCode) {
74   switch (UnwindCode.getUnwindOp()) {
75   default: llvm_unreachable("Invalid unwind code");
76   case UOP_PushNonVol:
77   case UOP_AllocSmall:
78   case UOP_SetFPReg:
79   case UOP_PushMachFrame:
80     return 1;
81   case UOP_SaveNonVol:
82   case UOP_SaveXMM128:
83     return 2;
84   case UOP_SaveNonVolBig:
85   case UOP_SaveXMM128Big:
86     return 3;
87   case UOP_AllocLarge:
88     return (UnwindCode.getOpInfo() == 0) ? 2 : 3;
89   }
90 }
91 
92 // Prints one unwind code. Because an unwind code can occupy up to 3 slots in
93 // the unwind codes array, this function requires that the correct number of
94 // slots is provided.
printUnwindCode(ArrayRef<UnwindCode> UCs)95 static void printUnwindCode(ArrayRef<UnwindCode> UCs) {
96   assert(UCs.size() >= getNumUsedSlots(UCs[0]));
97   outs() <<  format("      0x%02x: ", unsigned(UCs[0].u.CodeOffset))
98          << getUnwindCodeTypeName(UCs[0].getUnwindOp());
99   switch (UCs[0].getUnwindOp()) {
100   case UOP_PushNonVol:
101     outs() << " " << getUnwindRegisterName(UCs[0].getOpInfo());
102     break;
103   case UOP_AllocLarge:
104     if (UCs[0].getOpInfo() == 0) {
105       outs() << " " << UCs[1].FrameOffset;
106     } else {
107       outs() << " " << UCs[1].FrameOffset
108                        + (static_cast<uint32_t>(UCs[2].FrameOffset) << 16);
109     }
110     break;
111   case UOP_AllocSmall:
112     outs() << " " << ((UCs[0].getOpInfo() + 1) * 8);
113     break;
114   case UOP_SetFPReg:
115     outs() << " ";
116     break;
117   case UOP_SaveNonVol:
118     outs() << " " << getUnwindRegisterName(UCs[0].getOpInfo())
119            << format(" [0x%04x]", 8 * UCs[1].FrameOffset);
120     break;
121   case UOP_SaveNonVolBig:
122     outs() << " " << getUnwindRegisterName(UCs[0].getOpInfo())
123            << format(" [0x%08x]", UCs[1].FrameOffset
124                     + (static_cast<uint32_t>(UCs[2].FrameOffset) << 16));
125     break;
126   case UOP_SaveXMM128:
127     outs() << " XMM" << static_cast<uint32_t>(UCs[0].getOpInfo())
128            << format(" [0x%04x]", 16 * UCs[1].FrameOffset);
129     break;
130   case UOP_SaveXMM128Big:
131     outs() << " XMM" << UCs[0].getOpInfo()
132            << format(" [0x%08x]", UCs[1].FrameOffset
133                            + (static_cast<uint32_t>(UCs[2].FrameOffset) << 16));
134     break;
135   case UOP_PushMachFrame:
136     outs() << " " << (UCs[0].getOpInfo() ? "w/o" : "w")
137            << " error code";
138     break;
139   }
140   outs() << "\n";
141 }
142 
printAllUnwindCodes(ArrayRef<UnwindCode> UCs)143 static void printAllUnwindCodes(ArrayRef<UnwindCode> UCs) {
144   for (const UnwindCode *I = UCs.begin(), *E = UCs.end(); I < E; ) {
145     unsigned UsedSlots = getNumUsedSlots(*I);
146     if (UsedSlots > UCs.size()) {
147       outs() << "Unwind data corrupted: Encountered unwind op "
148              << getUnwindCodeTypeName((*I).getUnwindOp())
149              << " which requires " << UsedSlots
150              << " slots, but only " << UCs.size()
151              << " remaining in buffer";
152       return ;
153     }
154     printUnwindCode(makeArrayRef(I, E));
155     I += UsedSlots;
156   }
157 }
158 
159 // Given a symbol sym this functions returns the address and section of it.
160 static std::error_code
resolveSectionAndAddress(const COFFObjectFile * Obj,const SymbolRef & Sym,const coff_section * & ResolvedSection,uint64_t & ResolvedAddr)161 resolveSectionAndAddress(const COFFObjectFile *Obj, const SymbolRef &Sym,
162                          const coff_section *&ResolvedSection,
163                          uint64_t &ResolvedAddr) {
164   Expected<uint64_t> ResolvedAddrOrErr = Sym.getAddress();
165   if (!ResolvedAddrOrErr)
166     return errorToErrorCode(ResolvedAddrOrErr.takeError());
167   ResolvedAddr = *ResolvedAddrOrErr;
168   Expected<section_iterator> Iter = Sym.getSection();
169   if (!Iter)
170     return errorToErrorCode(Iter.takeError());
171   ResolvedSection = Obj->getCOFFSection(**Iter);
172   return std::error_code();
173 }
174 
175 // Given a vector of relocations for a section and an offset into this section
176 // the function returns the symbol used for the relocation at the offset.
resolveSymbol(const std::vector<RelocationRef> & Rels,uint64_t Offset,SymbolRef & Sym)177 static std::error_code resolveSymbol(const std::vector<RelocationRef> &Rels,
178                                      uint64_t Offset, SymbolRef &Sym) {
179   for (std::vector<RelocationRef>::const_iterator I = Rels.begin(),
180                                                   E = Rels.end();
181                                                   I != E; ++I) {
182     uint64_t Ofs = I->getOffset();
183     if (Ofs == Offset) {
184       Sym = *I->getSymbol();
185       return std::error_code();
186     }
187   }
188   return object_error::parse_failed;
189 }
190 
191 // Given a vector of relocations for a section and an offset into this section
192 // the function resolves the symbol used for the relocation at the offset and
193 // returns the section content and the address inside the content pointed to
194 // by the symbol.
195 static std::error_code
getSectionContents(const COFFObjectFile * Obj,const std::vector<RelocationRef> & Rels,uint64_t Offset,ArrayRef<uint8_t> & Contents,uint64_t & Addr)196 getSectionContents(const COFFObjectFile *Obj,
197                    const std::vector<RelocationRef> &Rels, uint64_t Offset,
198                    ArrayRef<uint8_t> &Contents, uint64_t &Addr) {
199   SymbolRef Sym;
200   if (std::error_code EC = resolveSymbol(Rels, Offset, Sym))
201     return EC;
202   const coff_section *Section;
203   if (std::error_code EC = resolveSectionAndAddress(Obj, Sym, Section, Addr))
204     return EC;
205   if (std::error_code EC = Obj->getSectionContents(Section, Contents))
206     return EC;
207   return std::error_code();
208 }
209 
210 // Given a vector of relocations for a section and an offset into this section
211 // the function returns the name of the symbol used for the relocation at the
212 // offset.
resolveSymbolName(const std::vector<RelocationRef> & Rels,uint64_t Offset,StringRef & Name)213 static std::error_code resolveSymbolName(const std::vector<RelocationRef> &Rels,
214                                          uint64_t Offset, StringRef &Name) {
215   SymbolRef Sym;
216   if (std::error_code EC = resolveSymbol(Rels, Offset, Sym))
217     return EC;
218   Expected<StringRef> NameOrErr = Sym.getName();
219   if (!NameOrErr)
220     return errorToErrorCode(NameOrErr.takeError());
221   Name = *NameOrErr;
222   return std::error_code();
223 }
224 
printCOFFSymbolAddress(llvm::raw_ostream & Out,const std::vector<RelocationRef> & Rels,uint64_t Offset,uint32_t Disp)225 static void printCOFFSymbolAddress(llvm::raw_ostream &Out,
226                                    const std::vector<RelocationRef> &Rels,
227                                    uint64_t Offset, uint32_t Disp) {
228   StringRef Sym;
229   if (!resolveSymbolName(Rels, Offset, Sym)) {
230     Out << Sym;
231     if (Disp > 0)
232       Out << format(" + 0x%04x", Disp);
233   } else {
234     Out << format("0x%04x", Disp);
235   }
236 }
237 
238 static void
printSEHTable(const COFFObjectFile * Obj,uint32_t TableVA,int Count)239 printSEHTable(const COFFObjectFile *Obj, uint32_t TableVA, int Count) {
240   if (Count == 0)
241     return;
242 
243   const pe32_header *PE32Header;
244   error(Obj->getPE32Header(PE32Header));
245   uint32_t ImageBase = PE32Header->ImageBase;
246   uintptr_t IntPtr = 0;
247   error(Obj->getVaPtr(TableVA, IntPtr));
248   const support::ulittle32_t *P = (const support::ulittle32_t *)IntPtr;
249   outs() << "SEH Table:";
250   for (int I = 0; I < Count; ++I)
251     outs() << format(" 0x%x", P[I] + ImageBase);
252   outs() << "\n\n";
253 }
254 
255 template <typename T>
printTLSDirectoryT(const coff_tls_directory<T> * TLSDir)256 static void printTLSDirectoryT(const coff_tls_directory<T> *TLSDir) {
257   size_t FormatWidth = sizeof(T) * 2;
258   outs() << "TLS directory:"
259          << "\n  StartAddressOfRawData: "
260          << format_hex(TLSDir->StartAddressOfRawData, FormatWidth)
261          << "\n  EndAddressOfRawData: "
262          << format_hex(TLSDir->EndAddressOfRawData, FormatWidth)
263          << "\n  AddressOfIndex: "
264          << format_hex(TLSDir->AddressOfIndex, FormatWidth)
265          << "\n  AddressOfCallBacks: "
266          << format_hex(TLSDir->AddressOfCallBacks, FormatWidth)
267          << "\n  SizeOfZeroFill: "
268          << TLSDir->SizeOfZeroFill
269          << "\n  Characteristics: "
270          << TLSDir->Characteristics
271          << "\n  Alignment: "
272          << TLSDir->getAlignment()
273          << "\n\n";
274 }
275 
printTLSDirectory(const COFFObjectFile * Obj)276 static void printTLSDirectory(const COFFObjectFile *Obj) {
277   const pe32_header *PE32Header;
278   error(Obj->getPE32Header(PE32Header));
279 
280   const pe32plus_header *PE32PlusHeader;
281   error(Obj->getPE32PlusHeader(PE32PlusHeader));
282 
283   // Skip if it's not executable.
284   if (!PE32Header && !PE32PlusHeader)
285     return;
286 
287   const data_directory *DataDir;
288   error(Obj->getDataDirectory(COFF::TLS_TABLE, DataDir));
289   uintptr_t IntPtr = 0;
290   if (DataDir->RelativeVirtualAddress == 0)
291     return;
292   error(Obj->getRvaPtr(DataDir->RelativeVirtualAddress, IntPtr));
293 
294   if (PE32Header) {
295     auto *TLSDir = reinterpret_cast<const coff_tls_directory32 *>(IntPtr);
296     printTLSDirectoryT(TLSDir);
297   } else {
298     auto *TLSDir = reinterpret_cast<const coff_tls_directory64 *>(IntPtr);
299     printTLSDirectoryT(TLSDir);
300   }
301 
302   outs() << "\n";
303 }
304 
printLoadConfiguration(const COFFObjectFile * Obj)305 static void printLoadConfiguration(const COFFObjectFile *Obj) {
306   // Skip if it's not executable.
307   const pe32_header *PE32Header;
308   error(Obj->getPE32Header(PE32Header));
309   if (!PE32Header)
310     return;
311 
312   // Currently only x86 is supported
313   if (Obj->getMachine() != COFF::IMAGE_FILE_MACHINE_I386)
314     return;
315 
316   const data_directory *DataDir;
317   error(Obj->getDataDirectory(COFF::LOAD_CONFIG_TABLE, DataDir));
318   uintptr_t IntPtr = 0;
319   if (DataDir->RelativeVirtualAddress == 0)
320     return;
321   error(Obj->getRvaPtr(DataDir->RelativeVirtualAddress, IntPtr));
322 
323   auto *LoadConf = reinterpret_cast<const coff_load_configuration32 *>(IntPtr);
324   outs() << "Load configuration:"
325          << "\n  Timestamp: " << LoadConf->TimeDateStamp
326          << "\n  Major Version: " << LoadConf->MajorVersion
327          << "\n  Minor Version: " << LoadConf->MinorVersion
328          << "\n  GlobalFlags Clear: " << LoadConf->GlobalFlagsClear
329          << "\n  GlobalFlags Set: " << LoadConf->GlobalFlagsSet
330          << "\n  Critical Section Default Timeout: " << LoadConf->CriticalSectionDefaultTimeout
331          << "\n  Decommit Free Block Threshold: " << LoadConf->DeCommitFreeBlockThreshold
332          << "\n  Decommit Total Free Threshold: " << LoadConf->DeCommitTotalFreeThreshold
333          << "\n  Lock Prefix Table: " << LoadConf->LockPrefixTable
334          << "\n  Maximum Allocation Size: " << LoadConf->MaximumAllocationSize
335          << "\n  Virtual Memory Threshold: " << LoadConf->VirtualMemoryThreshold
336          << "\n  Process Affinity Mask: " << LoadConf->ProcessAffinityMask
337          << "\n  Process Heap Flags: " << LoadConf->ProcessHeapFlags
338          << "\n  CSD Version: " << LoadConf->CSDVersion
339          << "\n  Security Cookie: " << LoadConf->SecurityCookie
340          << "\n  SEH Table: " << LoadConf->SEHandlerTable
341          << "\n  SEH Count: " << LoadConf->SEHandlerCount
342          << "\n\n";
343   printSEHTable(Obj, LoadConf->SEHandlerTable, LoadConf->SEHandlerCount);
344   outs() << "\n";
345 }
346 
347 // Prints import tables. The import table is a table containing the list of
348 // DLL name and symbol names which will be linked by the loader.
printImportTables(const COFFObjectFile * Obj)349 static void printImportTables(const COFFObjectFile *Obj) {
350   import_directory_iterator I = Obj->import_directory_begin();
351   import_directory_iterator E = Obj->import_directory_end();
352   if (I == E)
353     return;
354   outs() << "The Import Tables:\n";
355   for (const ImportDirectoryEntryRef &DirRef : Obj->import_directories()) {
356     const import_directory_table_entry *Dir;
357     StringRef Name;
358     if (DirRef.getImportTableEntry(Dir)) return;
359     if (DirRef.getName(Name)) return;
360 
361     outs() << format("  lookup %08x time %08x fwd %08x name %08x addr %08x\n\n",
362                      static_cast<uint32_t>(Dir->ImportLookupTableRVA),
363                      static_cast<uint32_t>(Dir->TimeDateStamp),
364                      static_cast<uint32_t>(Dir->ForwarderChain),
365                      static_cast<uint32_t>(Dir->NameRVA),
366                      static_cast<uint32_t>(Dir->ImportAddressTableRVA));
367     outs() << "    DLL Name: " << Name << "\n";
368     outs() << "    Hint/Ord  Name\n";
369     for (const ImportedSymbolRef &Entry : DirRef.imported_symbols()) {
370       bool IsOrdinal;
371       if (Entry.isOrdinal(IsOrdinal))
372         return;
373       if (IsOrdinal) {
374         uint16_t Ordinal;
375         if (Entry.getOrdinal(Ordinal))
376           return;
377         outs() << format("      % 6d\n", Ordinal);
378         continue;
379       }
380       uint32_t HintNameRVA;
381       if (Entry.getHintNameRVA(HintNameRVA))
382         return;
383       uint16_t Hint;
384       StringRef Name;
385       if (Obj->getHintName(HintNameRVA, Hint, Name))
386         return;
387       outs() << format("      % 6d  ", Hint) << Name << "\n";
388     }
389     outs() << "\n";
390   }
391 }
392 
393 // Prints export tables. The export table is a table containing the list of
394 // exported symbol from the DLL.
printExportTable(const COFFObjectFile * Obj)395 static void printExportTable(const COFFObjectFile *Obj) {
396   outs() << "Export Table:\n";
397   export_directory_iterator I = Obj->export_directory_begin();
398   export_directory_iterator E = Obj->export_directory_end();
399   if (I == E)
400     return;
401   StringRef DllName;
402   uint32_t OrdinalBase;
403   if (I->getDllName(DllName))
404     return;
405   if (I->getOrdinalBase(OrdinalBase))
406     return;
407   outs() << " DLL name: " << DllName << "\n";
408   outs() << " Ordinal base: " << OrdinalBase << "\n";
409   outs() << " Ordinal      RVA  Name\n";
410   for (; I != E; I = ++I) {
411     uint32_t Ordinal;
412     if (I->getOrdinal(Ordinal))
413       return;
414     uint32_t RVA;
415     if (I->getExportRVA(RVA))
416       return;
417     bool IsForwarder;
418     if (I->isForwarder(IsForwarder))
419       return;
420 
421     if (IsForwarder) {
422       // Export table entries can be used to re-export symbols that
423       // this COFF file is imported from some DLLs. This is rare.
424       // In most cases IsForwarder is false.
425       outs() << format("    % 4d         ", Ordinal);
426     } else {
427       outs() << format("    % 4d %# 8x", Ordinal, RVA);
428     }
429 
430     StringRef Name;
431     if (I->getSymbolName(Name))
432       continue;
433     if (!Name.empty())
434       outs() << "  " << Name;
435     if (IsForwarder) {
436       StringRef S;
437       if (I->getForwardTo(S))
438         return;
439       outs() << " (forwarded to " << S << ")";
440     }
441     outs() << "\n";
442   }
443 }
444 
445 // Given the COFF object file, this function returns the relocations for .pdata
446 // and the pointer to "runtime function" structs.
getPDataSection(const COFFObjectFile * Obj,std::vector<RelocationRef> & Rels,const RuntimeFunction * & RFStart,int & NumRFs)447 static bool getPDataSection(const COFFObjectFile *Obj,
448                             std::vector<RelocationRef> &Rels,
449                             const RuntimeFunction *&RFStart, int &NumRFs) {
450   for (const SectionRef &Section : Obj->sections()) {
451     StringRef Name;
452     error(Section.getName(Name));
453     if (Name != ".pdata")
454       continue;
455 
456     const coff_section *Pdata = Obj->getCOFFSection(Section);
457     for (const RelocationRef &Reloc : Section.relocations())
458       Rels.push_back(Reloc);
459 
460     // Sort relocations by address.
461     std::sort(Rels.begin(), Rels.end(), RelocAddressLess);
462 
463     ArrayRef<uint8_t> Contents;
464     error(Obj->getSectionContents(Pdata, Contents));
465     if (Contents.empty())
466       continue;
467 
468     RFStart = reinterpret_cast<const RuntimeFunction *>(Contents.data());
469     NumRFs = Contents.size() / sizeof(RuntimeFunction);
470     return true;
471   }
472   return false;
473 }
474 
printWin64EHUnwindInfo(const Win64EH::UnwindInfo * UI)475 static void printWin64EHUnwindInfo(const Win64EH::UnwindInfo *UI) {
476   // The casts to int are required in order to output the value as number.
477   // Without the casts the value would be interpreted as char data (which
478   // results in garbage output).
479   outs() << "    Version: " << static_cast<int>(UI->getVersion()) << "\n";
480   outs() << "    Flags: " << static_cast<int>(UI->getFlags());
481   if (UI->getFlags()) {
482     if (UI->getFlags() & UNW_ExceptionHandler)
483       outs() << " UNW_ExceptionHandler";
484     if (UI->getFlags() & UNW_TerminateHandler)
485       outs() << " UNW_TerminateHandler";
486     if (UI->getFlags() & UNW_ChainInfo)
487       outs() << " UNW_ChainInfo";
488   }
489   outs() << "\n";
490   outs() << "    Size of prolog: " << static_cast<int>(UI->PrologSize) << "\n";
491   outs() << "    Number of Codes: " << static_cast<int>(UI->NumCodes) << "\n";
492   // Maybe this should move to output of UOP_SetFPReg?
493   if (UI->getFrameRegister()) {
494     outs() << "    Frame register: "
495            << getUnwindRegisterName(UI->getFrameRegister()) << "\n";
496     outs() << "    Frame offset: " << 16 * UI->getFrameOffset() << "\n";
497   } else {
498     outs() << "    No frame pointer used\n";
499   }
500   if (UI->getFlags() & (UNW_ExceptionHandler | UNW_TerminateHandler)) {
501     // FIXME: Output exception handler data
502   } else if (UI->getFlags() & UNW_ChainInfo) {
503     // FIXME: Output chained unwind info
504   }
505 
506   if (UI->NumCodes)
507     outs() << "    Unwind Codes:\n";
508 
509   printAllUnwindCodes(makeArrayRef(&UI->UnwindCodes[0], UI->NumCodes));
510 
511   outs() << "\n";
512   outs().flush();
513 }
514 
515 /// Prints out the given RuntimeFunction struct for x64, assuming that Obj is
516 /// pointing to an executable file.
printRuntimeFunction(const COFFObjectFile * Obj,const RuntimeFunction & RF)517 static void printRuntimeFunction(const COFFObjectFile *Obj,
518                                  const RuntimeFunction &RF) {
519   if (!RF.StartAddress)
520     return;
521   outs() << "Function Table:\n"
522          << format("  Start Address: 0x%04x\n",
523                    static_cast<uint32_t>(RF.StartAddress))
524          << format("  End Address: 0x%04x\n",
525                    static_cast<uint32_t>(RF.EndAddress))
526          << format("  Unwind Info Address: 0x%04x\n",
527                    static_cast<uint32_t>(RF.UnwindInfoOffset));
528   uintptr_t addr;
529   if (Obj->getRvaPtr(RF.UnwindInfoOffset, addr))
530     return;
531   printWin64EHUnwindInfo(reinterpret_cast<const Win64EH::UnwindInfo *>(addr));
532 }
533 
534 /// Prints out the given RuntimeFunction struct for x64, assuming that Obj is
535 /// pointing to an object file. Unlike executable, fields in RuntimeFunction
536 /// struct are filled with zeros, but instead there are relocations pointing to
537 /// them so that the linker will fill targets' RVAs to the fields at link
538 /// time. This function interprets the relocations to find the data to be used
539 /// in the resulting executable.
printRuntimeFunctionRels(const COFFObjectFile * Obj,const RuntimeFunction & RF,uint64_t SectionOffset,const std::vector<RelocationRef> & Rels)540 static void printRuntimeFunctionRels(const COFFObjectFile *Obj,
541                                      const RuntimeFunction &RF,
542                                      uint64_t SectionOffset,
543                                      const std::vector<RelocationRef> &Rels) {
544   outs() << "Function Table:\n";
545   outs() << "  Start Address: ";
546   printCOFFSymbolAddress(outs(), Rels,
547                          SectionOffset +
548                              /*offsetof(RuntimeFunction, StartAddress)*/ 0,
549                          RF.StartAddress);
550   outs() << "\n";
551 
552   outs() << "  End Address: ";
553   printCOFFSymbolAddress(outs(), Rels,
554                          SectionOffset +
555                              /*offsetof(RuntimeFunction, EndAddress)*/ 4,
556                          RF.EndAddress);
557   outs() << "\n";
558 
559   outs() << "  Unwind Info Address: ";
560   printCOFFSymbolAddress(outs(), Rels,
561                          SectionOffset +
562                              /*offsetof(RuntimeFunction, UnwindInfoOffset)*/ 8,
563                          RF.UnwindInfoOffset);
564   outs() << "\n";
565 
566   ArrayRef<uint8_t> XContents;
567   uint64_t UnwindInfoOffset = 0;
568   error(getSectionContents(
569           Obj, Rels, SectionOffset +
570                          /*offsetof(RuntimeFunction, UnwindInfoOffset)*/ 8,
571           XContents, UnwindInfoOffset));
572   if (XContents.empty())
573     return;
574 
575   UnwindInfoOffset += RF.UnwindInfoOffset;
576   if (UnwindInfoOffset > XContents.size())
577     return;
578 
579   auto *UI = reinterpret_cast<const Win64EH::UnwindInfo *>(XContents.data() +
580                                                            UnwindInfoOffset);
581   printWin64EHUnwindInfo(UI);
582 }
583 
printCOFFUnwindInfo(const COFFObjectFile * Obj)584 void llvm::printCOFFUnwindInfo(const COFFObjectFile *Obj) {
585   if (Obj->getMachine() != COFF::IMAGE_FILE_MACHINE_AMD64) {
586     errs() << "Unsupported image machine type "
587               "(currently only AMD64 is supported).\n";
588     return;
589   }
590 
591   std::vector<RelocationRef> Rels;
592   const RuntimeFunction *RFStart;
593   int NumRFs;
594   if (!getPDataSection(Obj, Rels, RFStart, NumRFs))
595     return;
596   ArrayRef<RuntimeFunction> RFs(RFStart, NumRFs);
597 
598   bool IsExecutable = Rels.empty();
599   if (IsExecutable) {
600     for (const RuntimeFunction &RF : RFs)
601       printRuntimeFunction(Obj, RF);
602     return;
603   }
604 
605   for (const RuntimeFunction &RF : RFs) {
606     uint64_t SectionOffset =
607         std::distance(RFs.begin(), &RF) * sizeof(RuntimeFunction);
608     printRuntimeFunctionRels(Obj, RF, SectionOffset, Rels);
609   }
610 }
611 
printCOFFFileHeader(const object::ObjectFile * Obj)612 void llvm::printCOFFFileHeader(const object::ObjectFile *Obj) {
613   const COFFObjectFile *file = dyn_cast<const COFFObjectFile>(Obj);
614   printTLSDirectory(file);
615   printLoadConfiguration(file);
616   printImportTables(file);
617   printExportTable(file);
618 }
619 
printCOFFSymbolTable(const COFFObjectFile * coff)620 void llvm::printCOFFSymbolTable(const COFFObjectFile *coff) {
621   for (unsigned SI = 0, SE = coff->getNumberOfSymbols(); SI != SE; ++SI) {
622     ErrorOr<COFFSymbolRef> Symbol = coff->getSymbol(SI);
623     StringRef Name;
624     error(Symbol.getError());
625     error(coff->getSymbolName(*Symbol, Name));
626 
627     outs() << "[" << format("%2d", SI) << "]"
628            << "(sec " << format("%2d", int(Symbol->getSectionNumber())) << ")"
629            << "(fl 0x00)" // Flag bits, which COFF doesn't have.
630            << "(ty " << format("%3x", unsigned(Symbol->getType())) << ")"
631            << "(scl " << format("%3x", unsigned(Symbol->getStorageClass())) << ") "
632            << "(nx " << unsigned(Symbol->getNumberOfAuxSymbols()) << ") "
633            << "0x" << format("%08x", unsigned(Symbol->getValue())) << " "
634            << Name << "\n";
635 
636     for (unsigned AI = 0, AE = Symbol->getNumberOfAuxSymbols(); AI < AE; ++AI, ++SI) {
637       if (Symbol->isSectionDefinition()) {
638         const coff_aux_section_definition *asd;
639         error(coff->getAuxSymbol<coff_aux_section_definition>(SI + 1, asd));
640 
641         int32_t AuxNumber = asd->getNumber(Symbol->isBigObj());
642 
643         outs() << "AUX "
644                << format("scnlen 0x%x nreloc %d nlnno %d checksum 0x%x "
645                          , unsigned(asd->Length)
646                          , unsigned(asd->NumberOfRelocations)
647                          , unsigned(asd->NumberOfLinenumbers)
648                          , unsigned(asd->CheckSum))
649                << format("assoc %d comdat %d\n"
650                          , unsigned(AuxNumber)
651                          , unsigned(asd->Selection));
652       } else if (Symbol->isFileRecord()) {
653         const char *FileName;
654         error(coff->getAuxSymbol<char>(SI + 1, FileName));
655 
656         StringRef Name(FileName, Symbol->getNumberOfAuxSymbols() *
657                                      coff->getSymbolTableEntrySize());
658         outs() << "AUX " << Name.rtrim(StringRef("\0", 1))  << '\n';
659 
660         SI = SI + Symbol->getNumberOfAuxSymbols();
661         break;
662       } else if (Symbol->isWeakExternal()) {
663         const coff_aux_weak_external *awe;
664         error(coff->getAuxSymbol<coff_aux_weak_external>(SI + 1, awe));
665 
666         outs() << "AUX " << format("indx %d srch %d\n",
667                                    static_cast<uint32_t>(awe->TagIndex),
668                                    static_cast<uint32_t>(awe->Characteristics));
669       } else {
670         outs() << "AUX Unknown\n";
671       }
672     }
673   }
674 }
675