xref: /freebsd-12.1/contrib/llvm/tools/lld/COFF/DLL.cpp (revision b5893f02)
1 //===- DLL.cpp ------------------------------------------------------------===//
2 //
3 //                             The LLVM Linker
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 defines various types of chunks for the DLL import or export
11 // descriptor tables. They are inherently Windows-specific.
12 // You need to read Microsoft PE/COFF spec to understand details
13 // about the data structures.
14 //
15 // If you are not particularly interested in linking against Windows
16 // DLL, you can skip this file, and you should still be able to
17 // understand the rest of the linker.
18 //
19 //===----------------------------------------------------------------------===//
20 
21 #include "DLL.h"
22 #include "Chunks.h"
23 #include "llvm/Object/COFF.h"
24 #include "llvm/Support/Endian.h"
25 #include "llvm/Support/Path.h"
26 
27 using namespace llvm;
28 using namespace llvm::object;
29 using namespace llvm::support::endian;
30 using namespace llvm::COFF;
31 
32 namespace lld {
33 namespace coff {
34 namespace {
35 
36 // Import table
37 
38 // A chunk for the import descriptor table.
39 class HintNameChunk : public Chunk {
40 public:
HintNameChunk(StringRef N,uint16_t H)41   HintNameChunk(StringRef N, uint16_t H) : Name(N), Hint(H) {}
42 
getSize() const43   size_t getSize() const override {
44     // Starts with 2 byte Hint field, followed by a null-terminated string,
45     // ends with 0 or 1 byte padding.
46     return alignTo(Name.size() + 3, 2);
47   }
48 
writeTo(uint8_t * Buf) const49   void writeTo(uint8_t *Buf) const override {
50     memset(Buf + OutputSectionOff, 0, getSize());
51     write16le(Buf + OutputSectionOff, Hint);
52     memcpy(Buf + OutputSectionOff + 2, Name.data(), Name.size());
53   }
54 
55 private:
56   StringRef Name;
57   uint16_t Hint;
58 };
59 
60 // A chunk for the import descriptor table.
61 class LookupChunk : public Chunk {
62 public:
LookupChunk(Chunk * C)63   explicit LookupChunk(Chunk *C) : HintName(C) { Alignment = Config->Wordsize; }
getSize() const64   size_t getSize() const override { return Config->Wordsize; }
65 
writeTo(uint8_t * Buf) const66   void writeTo(uint8_t *Buf) const override {
67     if (Config->is64())
68       write64le(Buf + OutputSectionOff, HintName->getRVA());
69     else
70       write32le(Buf + OutputSectionOff, HintName->getRVA());
71   }
72 
73   Chunk *HintName;
74 };
75 
76 // A chunk for the import descriptor table.
77 // This chunk represent import-by-ordinal symbols.
78 // See Microsoft PE/COFF spec 7.1. Import Header for details.
79 class OrdinalOnlyChunk : public Chunk {
80 public:
OrdinalOnlyChunk(uint16_t V)81   explicit OrdinalOnlyChunk(uint16_t V) : Ordinal(V) {
82     Alignment = Config->Wordsize;
83   }
getSize() const84   size_t getSize() const override { return Config->Wordsize; }
85 
writeTo(uint8_t * Buf) const86   void writeTo(uint8_t *Buf) const override {
87     // An import-by-ordinal slot has MSB 1 to indicate that
88     // this is import-by-ordinal (and not import-by-name).
89     if (Config->is64()) {
90       write64le(Buf + OutputSectionOff, (1ULL << 63) | Ordinal);
91     } else {
92       write32le(Buf + OutputSectionOff, (1ULL << 31) | Ordinal);
93     }
94   }
95 
96   uint16_t Ordinal;
97 };
98 
99 // A chunk for the import descriptor table.
100 class ImportDirectoryChunk : public Chunk {
101 public:
ImportDirectoryChunk(Chunk * N)102   explicit ImportDirectoryChunk(Chunk *N) : DLLName(N) {}
getSize() const103   size_t getSize() const override { return sizeof(ImportDirectoryTableEntry); }
104 
writeTo(uint8_t * Buf) const105   void writeTo(uint8_t *Buf) const override {
106     memset(Buf + OutputSectionOff, 0, getSize());
107 
108     auto *E = (coff_import_directory_table_entry *)(Buf + OutputSectionOff);
109     E->ImportLookupTableRVA = LookupTab->getRVA();
110     E->NameRVA = DLLName->getRVA();
111     E->ImportAddressTableRVA = AddressTab->getRVA();
112   }
113 
114   Chunk *DLLName;
115   Chunk *LookupTab;
116   Chunk *AddressTab;
117 };
118 
119 // A chunk representing null terminator in the import table.
120 // Contents of this chunk is always null bytes.
121 class NullChunk : public Chunk {
122 public:
NullChunk(size_t N)123   explicit NullChunk(size_t N) : Size(N) {}
hasData() const124   bool hasData() const override { return false; }
getSize() const125   size_t getSize() const override { return Size; }
126 
writeTo(uint8_t * Buf) const127   void writeTo(uint8_t *Buf) const override {
128     memset(Buf + OutputSectionOff, 0, Size);
129   }
130 
131 private:
132   size_t Size;
133 };
134 
135 static std::vector<std::vector<DefinedImportData *>>
binImports(const std::vector<DefinedImportData * > & Imports)136 binImports(const std::vector<DefinedImportData *> &Imports) {
137   // Group DLL-imported symbols by DLL name because that's how
138   // symbols are layed out in the import descriptor table.
139   auto Less = [](const std::string &A, const std::string &B) {
140     return Config->DLLOrder[A] < Config->DLLOrder[B];
141   };
142   std::map<std::string, std::vector<DefinedImportData *>,
143            bool(*)(const std::string &, const std::string &)> M(Less);
144   for (DefinedImportData *Sym : Imports)
145     M[Sym->getDLLName().lower()].push_back(Sym);
146 
147   std::vector<std::vector<DefinedImportData *>> V;
148   for (auto &KV : M) {
149     // Sort symbols by name for each group.
150     std::vector<DefinedImportData *> &Syms = KV.second;
151     std::sort(Syms.begin(), Syms.end(),
152               [](DefinedImportData *A, DefinedImportData *B) {
153                 return A->getName() < B->getName();
154               });
155     V.push_back(std::move(Syms));
156   }
157   return V;
158 }
159 
160 // Export table
161 // See Microsoft PE/COFF spec 4.3 for details.
162 
163 // A chunk for the delay import descriptor table etnry.
164 class DelayDirectoryChunk : public Chunk {
165 public:
DelayDirectoryChunk(Chunk * N)166   explicit DelayDirectoryChunk(Chunk *N) : DLLName(N) {}
167 
getSize() const168   size_t getSize() const override {
169     return sizeof(delay_import_directory_table_entry);
170   }
171 
writeTo(uint8_t * Buf) const172   void writeTo(uint8_t *Buf) const override {
173     memset(Buf + OutputSectionOff, 0, getSize());
174 
175     auto *E = (delay_import_directory_table_entry *)(Buf + OutputSectionOff);
176     E->Attributes = 1;
177     E->Name = DLLName->getRVA();
178     E->ModuleHandle = ModuleHandle->getRVA();
179     E->DelayImportAddressTable = AddressTab->getRVA();
180     E->DelayImportNameTable = NameTab->getRVA();
181   }
182 
183   Chunk *DLLName;
184   Chunk *ModuleHandle;
185   Chunk *AddressTab;
186   Chunk *NameTab;
187 };
188 
189 // Initial contents for delay-loaded functions.
190 // This code calls __delayLoadHelper2 function to resolve a symbol
191 // and then overwrites its jump table slot with the result
192 // for subsequent function calls.
193 static const uint8_t ThunkX64[] = {
194     0x51,                               // push    rcx
195     0x52,                               // push    rdx
196     0x41, 0x50,                         // push    r8
197     0x41, 0x51,                         // push    r9
198     0x48, 0x83, 0xEC, 0x48,             // sub     rsp, 48h
199     0x66, 0x0F, 0x7F, 0x04, 0x24,       // movdqa  xmmword ptr [rsp], xmm0
200     0x66, 0x0F, 0x7F, 0x4C, 0x24, 0x10, // movdqa  xmmword ptr [rsp+10h], xmm1
201     0x66, 0x0F, 0x7F, 0x54, 0x24, 0x20, // movdqa  xmmword ptr [rsp+20h], xmm2
202     0x66, 0x0F, 0x7F, 0x5C, 0x24, 0x30, // movdqa  xmmword ptr [rsp+30h], xmm3
203     0x48, 0x8D, 0x15, 0, 0, 0, 0,       // lea     rdx, [__imp_<FUNCNAME>]
204     0x48, 0x8D, 0x0D, 0, 0, 0, 0,       // lea     rcx, [___DELAY_IMPORT_...]
205     0xE8, 0, 0, 0, 0,                   // call    __delayLoadHelper2
206     0x66, 0x0F, 0x6F, 0x04, 0x24,       // movdqa  xmm0, xmmword ptr [rsp]
207     0x66, 0x0F, 0x6F, 0x4C, 0x24, 0x10, // movdqa  xmm1, xmmword ptr [rsp+10h]
208     0x66, 0x0F, 0x6F, 0x54, 0x24, 0x20, // movdqa  xmm2, xmmword ptr [rsp+20h]
209     0x66, 0x0F, 0x6F, 0x5C, 0x24, 0x30, // movdqa  xmm3, xmmword ptr [rsp+30h]
210     0x48, 0x83, 0xC4, 0x48,             // add     rsp, 48h
211     0x41, 0x59,                         // pop     r9
212     0x41, 0x58,                         // pop     r8
213     0x5A,                               // pop     rdx
214     0x59,                               // pop     rcx
215     0xFF, 0xE0,                         // jmp     rax
216 };
217 
218 static const uint8_t ThunkX86[] = {
219     0x51,              // push  ecx
220     0x52,              // push  edx
221     0x68, 0, 0, 0, 0,  // push  offset ___imp__<FUNCNAME>
222     0x68, 0, 0, 0, 0,  // push  offset ___DELAY_IMPORT_DESCRIPTOR_<DLLNAME>_dll
223     0xE8, 0, 0, 0, 0,  // call  ___delayLoadHelper2@8
224     0x5A,              // pop   edx
225     0x59,              // pop   ecx
226     0xFF, 0xE0,        // jmp   eax
227 };
228 
229 static const uint8_t ThunkARM[] = {
230     0x40, 0xf2, 0x00, 0x0c, // mov.w   ip, #0 __imp_<FUNCNAME>
231     0xc0, 0xf2, 0x00, 0x0c, // mov.t   ip, #0 __imp_<FUNCNAME>
232     0x2d, 0xe9, 0x0f, 0x48, // push.w  {r0, r1, r2, r3, r11, lr}
233     0x0d, 0xf2, 0x10, 0x0b, // addw    r11, sp, #16
234     0x2d, 0xed, 0x10, 0x0b, // vpush   {d0, d1, d2, d3, d4, d5, d6, d7}
235     0x61, 0x46,             // mov     r1, ip
236     0x40, 0xf2, 0x00, 0x00, // mov.w   r0, #0 DELAY_IMPORT_DESCRIPTOR
237     0xc0, 0xf2, 0x00, 0x00, // mov.t   r0, #0 DELAY_IMPORT_DESCRIPTOR
238     0x00, 0xf0, 0x00, 0xd0, // bl      #0 __delayLoadHelper2
239     0x84, 0x46,             // mov     ip, r0
240     0xbd, 0xec, 0x10, 0x0b, // vpop    {d0, d1, d2, d3, d4, d5, d6, d7}
241     0xbd, 0xe8, 0x0f, 0x48, // pop.w   {r0, r1, r2, r3, r11, lr}
242     0x60, 0x47,             // bx      ip
243 };
244 
245 static const uint8_t ThunkARM64[] = {
246     0x11, 0x00, 0x00, 0x90, // adrp    x17, #0      __imp_<FUNCNAME>
247     0x31, 0x02, 0x00, 0x91, // add     x17, x17, #0 :lo12:__imp_<FUNCNAME>
248     0xfd, 0x7b, 0xb3, 0xa9, // stp     x29, x30, [sp, #-208]!
249     0xfd, 0x03, 0x00, 0x91, // mov     x29, sp
250     0xe0, 0x07, 0x01, 0xa9, // stp     x0, x1, [sp, #16]
251     0xe2, 0x0f, 0x02, 0xa9, // stp     x2, x3, [sp, #32]
252     0xe4, 0x17, 0x03, 0xa9, // stp     x4, x5, [sp, #48]
253     0xe6, 0x1f, 0x04, 0xa9, // stp     x6, x7, [sp, #64]
254     0xe0, 0x87, 0x02, 0xad, // stp     q0, q1, [sp, #80]
255     0xe2, 0x8f, 0x03, 0xad, // stp     q2, q3, [sp, #112]
256     0xe4, 0x97, 0x04, 0xad, // stp     q4, q5, [sp, #144]
257     0xe6, 0x9f, 0x05, 0xad, // stp     q6, q7, [sp, #176]
258     0xe1, 0x03, 0x11, 0xaa, // mov     x1, x17
259     0x00, 0x00, 0x00, 0x90, // adrp    x0, #0     DELAY_IMPORT_DESCRIPTOR
260     0x00, 0x00, 0x00, 0x91, // add     x0, x0, #0 :lo12:DELAY_IMPORT_DESCRIPTOR
261     0x00, 0x00, 0x00, 0x94, // bl      #0 __delayLoadHelper2
262     0xf0, 0x03, 0x00, 0xaa, // mov     x16, x0
263     0xe6, 0x9f, 0x45, 0xad, // ldp     q6, q7, [sp, #176]
264     0xe4, 0x97, 0x44, 0xad, // ldp     q4, q5, [sp, #144]
265     0xe2, 0x8f, 0x43, 0xad, // ldp     q2, q3, [sp, #112]
266     0xe0, 0x87, 0x42, 0xad, // ldp     q0, q1, [sp, #80]
267     0xe6, 0x1f, 0x44, 0xa9, // ldp     x6, x7, [sp, #64]
268     0xe4, 0x17, 0x43, 0xa9, // ldp     x4, x5, [sp, #48]
269     0xe2, 0x0f, 0x42, 0xa9, // ldp     x2, x3, [sp, #32]
270     0xe0, 0x07, 0x41, 0xa9, // ldp     x0, x1, [sp, #16]
271     0xfd, 0x7b, 0xcd, 0xa8, // ldp     x29, x30, [sp], #208
272     0x00, 0x02, 0x1f, 0xd6, // br      x16
273 };
274 
275 // A chunk for the delay import thunk.
276 class ThunkChunkX64 : public Chunk {
277 public:
ThunkChunkX64(Defined * I,Chunk * D,Defined * H)278   ThunkChunkX64(Defined *I, Chunk *D, Defined *H)
279       : Imp(I), Desc(D), Helper(H) {}
280 
getSize() const281   size_t getSize() const override { return sizeof(ThunkX64); }
282 
writeTo(uint8_t * Buf) const283   void writeTo(uint8_t *Buf) const override {
284     memcpy(Buf + OutputSectionOff, ThunkX64, sizeof(ThunkX64));
285     write32le(Buf + OutputSectionOff + 36, Imp->getRVA() - RVA - 40);
286     write32le(Buf + OutputSectionOff + 43, Desc->getRVA() - RVA - 47);
287     write32le(Buf + OutputSectionOff + 48, Helper->getRVA() - RVA - 52);
288   }
289 
290   Defined *Imp = nullptr;
291   Chunk *Desc = nullptr;
292   Defined *Helper = nullptr;
293 };
294 
295 class ThunkChunkX86 : public Chunk {
296 public:
ThunkChunkX86(Defined * I,Chunk * D,Defined * H)297   ThunkChunkX86(Defined *I, Chunk *D, Defined *H)
298       : Imp(I), Desc(D), Helper(H) {}
299 
getSize() const300   size_t getSize() const override { return sizeof(ThunkX86); }
301 
writeTo(uint8_t * Buf) const302   void writeTo(uint8_t *Buf) const override {
303     memcpy(Buf + OutputSectionOff, ThunkX86, sizeof(ThunkX86));
304     write32le(Buf + OutputSectionOff + 3, Imp->getRVA() + Config->ImageBase);
305     write32le(Buf + OutputSectionOff + 8, Desc->getRVA() + Config->ImageBase);
306     write32le(Buf + OutputSectionOff + 13, Helper->getRVA() - RVA - 17);
307   }
308 
getBaserels(std::vector<Baserel> * Res)309   void getBaserels(std::vector<Baserel> *Res) override {
310     Res->emplace_back(RVA + 3);
311     Res->emplace_back(RVA + 8);
312   }
313 
314   Defined *Imp = nullptr;
315   Chunk *Desc = nullptr;
316   Defined *Helper = nullptr;
317 };
318 
319 class ThunkChunkARM : public Chunk {
320 public:
ThunkChunkARM(Defined * I,Chunk * D,Defined * H)321   ThunkChunkARM(Defined *I, Chunk *D, Defined *H)
322       : Imp(I), Desc(D), Helper(H) {}
323 
getSize() const324   size_t getSize() const override { return sizeof(ThunkARM); }
325 
writeTo(uint8_t * Buf) const326   void writeTo(uint8_t *Buf) const override {
327     memcpy(Buf + OutputSectionOff, ThunkARM, sizeof(ThunkARM));
328     applyMOV32T(Buf + OutputSectionOff + 0, Imp->getRVA() + Config->ImageBase);
329     applyMOV32T(Buf + OutputSectionOff + 22, Desc->getRVA() + Config->ImageBase);
330     applyBranch24T(Buf + OutputSectionOff + 30, Helper->getRVA() - RVA - 34);
331   }
332 
getBaserels(std::vector<Baserel> * Res)333   void getBaserels(std::vector<Baserel> *Res) override {
334     Res->emplace_back(RVA + 0, IMAGE_REL_BASED_ARM_MOV32T);
335     Res->emplace_back(RVA + 22, IMAGE_REL_BASED_ARM_MOV32T);
336   }
337 
338   Defined *Imp = nullptr;
339   Chunk *Desc = nullptr;
340   Defined *Helper = nullptr;
341 };
342 
343 class ThunkChunkARM64 : public Chunk {
344 public:
ThunkChunkARM64(Defined * I,Chunk * D,Defined * H)345   ThunkChunkARM64(Defined *I, Chunk *D, Defined *H)
346       : Imp(I), Desc(D), Helper(H) {}
347 
getSize() const348   size_t getSize() const override { return sizeof(ThunkARM64); }
349 
writeTo(uint8_t * Buf) const350   void writeTo(uint8_t *Buf) const override {
351     memcpy(Buf + OutputSectionOff, ThunkARM64, sizeof(ThunkARM64));
352     applyArm64Addr(Buf + OutputSectionOff + 0, Imp->getRVA(), RVA + 0, 12);
353     applyArm64Imm(Buf + OutputSectionOff + 4, Imp->getRVA() & 0xfff, 0);
354     applyArm64Addr(Buf + OutputSectionOff + 52, Desc->getRVA(), RVA + 52, 12);
355     applyArm64Imm(Buf + OutputSectionOff + 56, Desc->getRVA() & 0xfff, 0);
356     applyArm64Branch26(Buf + OutputSectionOff + 60,
357                        Helper->getRVA() - RVA - 60);
358   }
359 
360   Defined *Imp = nullptr;
361   Chunk *Desc = nullptr;
362   Defined *Helper = nullptr;
363 };
364 
365 // A chunk for the import descriptor table.
366 class DelayAddressChunk : public Chunk {
367 public:
DelayAddressChunk(Chunk * C)368   explicit DelayAddressChunk(Chunk *C) : Thunk(C) {
369     Alignment = Config->Wordsize;
370   }
getSize() const371   size_t getSize() const override { return Config->Wordsize; }
372 
writeTo(uint8_t * Buf) const373   void writeTo(uint8_t *Buf) const override {
374     if (Config->is64()) {
375       write64le(Buf + OutputSectionOff, Thunk->getRVA() + Config->ImageBase);
376     } else {
377       uint32_t Bit = 0;
378       // Pointer to thumb code must have the LSB set, so adjust it.
379       if (Config->Machine == ARMNT)
380         Bit = 1;
381       write32le(Buf + OutputSectionOff, (Thunk->getRVA() + Config->ImageBase) | Bit);
382     }
383   }
384 
getBaserels(std::vector<Baserel> * Res)385   void getBaserels(std::vector<Baserel> *Res) override {
386     Res->emplace_back(RVA);
387   }
388 
389   Chunk *Thunk;
390 };
391 
392 // Export table
393 // Read Microsoft PE/COFF spec 5.3 for details.
394 
395 // A chunk for the export descriptor table.
396 class ExportDirectoryChunk : public Chunk {
397 public:
ExportDirectoryChunk(int I,int J,Chunk * D,Chunk * A,Chunk * N,Chunk * O)398   ExportDirectoryChunk(int I, int J, Chunk *D, Chunk *A, Chunk *N, Chunk *O)
399       : MaxOrdinal(I), NameTabSize(J), DLLName(D), AddressTab(A), NameTab(N),
400         OrdinalTab(O) {}
401 
getSize() const402   size_t getSize() const override {
403     return sizeof(export_directory_table_entry);
404   }
405 
writeTo(uint8_t * Buf) const406   void writeTo(uint8_t *Buf) const override {
407     memset(Buf + OutputSectionOff, 0, getSize());
408 
409     auto *E = (export_directory_table_entry *)(Buf + OutputSectionOff);
410     E->NameRVA = DLLName->getRVA();
411     E->OrdinalBase = 0;
412     E->AddressTableEntries = MaxOrdinal + 1;
413     E->NumberOfNamePointers = NameTabSize;
414     E->ExportAddressTableRVA = AddressTab->getRVA();
415     E->NamePointerRVA = NameTab->getRVA();
416     E->OrdinalTableRVA = OrdinalTab->getRVA();
417   }
418 
419   uint16_t MaxOrdinal;
420   uint16_t NameTabSize;
421   Chunk *DLLName;
422   Chunk *AddressTab;
423   Chunk *NameTab;
424   Chunk *OrdinalTab;
425 };
426 
427 class AddressTableChunk : public Chunk {
428 public:
AddressTableChunk(size_t MaxOrdinal)429   explicit AddressTableChunk(size_t MaxOrdinal) : Size(MaxOrdinal + 1) {}
getSize() const430   size_t getSize() const override { return Size * 4; }
431 
writeTo(uint8_t * Buf) const432   void writeTo(uint8_t *Buf) const override {
433     memset(Buf + OutputSectionOff, 0, getSize());
434 
435     for (const Export &E : Config->Exports) {
436       uint8_t *P = Buf + OutputSectionOff + E.Ordinal * 4;
437       uint32_t Bit = 0;
438       // Pointer to thumb code must have the LSB set, so adjust it.
439       if (Config->Machine == ARMNT && !E.Data)
440         Bit = 1;
441       if (E.ForwardChunk) {
442         write32le(P, E.ForwardChunk->getRVA() | Bit);
443       } else {
444         write32le(P, cast<Defined>(E.Sym)->getRVA() | Bit);
445       }
446     }
447   }
448 
449 private:
450   size_t Size;
451 };
452 
453 class NamePointersChunk : public Chunk {
454 public:
NamePointersChunk(std::vector<Chunk * > & V)455   explicit NamePointersChunk(std::vector<Chunk *> &V) : Chunks(V) {}
getSize() const456   size_t getSize() const override { return Chunks.size() * 4; }
457 
writeTo(uint8_t * Buf) const458   void writeTo(uint8_t *Buf) const override {
459     uint8_t *P = Buf + OutputSectionOff;
460     for (Chunk *C : Chunks) {
461       write32le(P, C->getRVA());
462       P += 4;
463     }
464   }
465 
466 private:
467   std::vector<Chunk *> Chunks;
468 };
469 
470 class ExportOrdinalChunk : public Chunk {
471 public:
ExportOrdinalChunk(size_t I)472   explicit ExportOrdinalChunk(size_t I) : Size(I) {}
getSize() const473   size_t getSize() const override { return Size * 2; }
474 
writeTo(uint8_t * Buf) const475   void writeTo(uint8_t *Buf) const override {
476     uint8_t *P = Buf + OutputSectionOff;
477     for (Export &E : Config->Exports) {
478       if (E.Noname)
479         continue;
480       write16le(P, E.Ordinal);
481       P += 2;
482     }
483   }
484 
485 private:
486   size_t Size;
487 };
488 
489 } // anonymous namespace
490 
create()491 void IdataContents::create() {
492   std::vector<std::vector<DefinedImportData *>> V = binImports(Imports);
493 
494   // Create .idata contents for each DLL.
495   for (std::vector<DefinedImportData *> &Syms : V) {
496     // Create lookup and address tables. If they have external names,
497     // we need to create HintName chunks to store the names.
498     // If they don't (if they are import-by-ordinals), we store only
499     // ordinal values to the table.
500     size_t Base = Lookups.size();
501     for (DefinedImportData *S : Syms) {
502       uint16_t Ord = S->getOrdinal();
503       if (S->getExternalName().empty()) {
504         Lookups.push_back(make<OrdinalOnlyChunk>(Ord));
505         Addresses.push_back(make<OrdinalOnlyChunk>(Ord));
506         continue;
507       }
508       auto *C = make<HintNameChunk>(S->getExternalName(), Ord);
509       Lookups.push_back(make<LookupChunk>(C));
510       Addresses.push_back(make<LookupChunk>(C));
511       Hints.push_back(C);
512     }
513     // Terminate with null values.
514     Lookups.push_back(make<NullChunk>(Config->Wordsize));
515     Addresses.push_back(make<NullChunk>(Config->Wordsize));
516 
517     for (int I = 0, E = Syms.size(); I < E; ++I)
518       Syms[I]->setLocation(Addresses[Base + I]);
519 
520     // Create the import table header.
521     DLLNames.push_back(make<StringChunk>(Syms[0]->getDLLName()));
522     auto *Dir = make<ImportDirectoryChunk>(DLLNames.back());
523     Dir->LookupTab = Lookups[Base];
524     Dir->AddressTab = Addresses[Base];
525     Dirs.push_back(Dir);
526   }
527   // Add null terminator.
528   Dirs.push_back(make<NullChunk>(sizeof(ImportDirectoryTableEntry)));
529 }
530 
getChunks()531 std::vector<Chunk *> DelayLoadContents::getChunks() {
532   std::vector<Chunk *> V;
533   V.insert(V.end(), Dirs.begin(), Dirs.end());
534   V.insert(V.end(), Names.begin(), Names.end());
535   V.insert(V.end(), HintNames.begin(), HintNames.end());
536   V.insert(V.end(), DLLNames.begin(), DLLNames.end());
537   return V;
538 }
539 
getDataChunks()540 std::vector<Chunk *> DelayLoadContents::getDataChunks() {
541   std::vector<Chunk *> V;
542   V.insert(V.end(), ModuleHandles.begin(), ModuleHandles.end());
543   V.insert(V.end(), Addresses.begin(), Addresses.end());
544   return V;
545 }
546 
getDirSize()547 uint64_t DelayLoadContents::getDirSize() {
548   return Dirs.size() * sizeof(delay_import_directory_table_entry);
549 }
550 
create(Defined * H)551 void DelayLoadContents::create(Defined *H) {
552   Helper = H;
553   std::vector<std::vector<DefinedImportData *>> V = binImports(Imports);
554 
555   // Create .didat contents for each DLL.
556   for (std::vector<DefinedImportData *> &Syms : V) {
557     // Create the delay import table header.
558     DLLNames.push_back(make<StringChunk>(Syms[0]->getDLLName()));
559     auto *Dir = make<DelayDirectoryChunk>(DLLNames.back());
560 
561     size_t Base = Addresses.size();
562     for (DefinedImportData *S : Syms) {
563       Chunk *T = newThunkChunk(S, Dir);
564       auto *A = make<DelayAddressChunk>(T);
565       Addresses.push_back(A);
566       Thunks.push_back(T);
567       StringRef ExtName = S->getExternalName();
568       if (ExtName.empty()) {
569         Names.push_back(make<OrdinalOnlyChunk>(S->getOrdinal()));
570       } else {
571         auto *C = make<HintNameChunk>(ExtName, 0);
572         Names.push_back(make<LookupChunk>(C));
573         HintNames.push_back(C);
574       }
575     }
576     // Terminate with null values.
577     Addresses.push_back(make<NullChunk>(8));
578     Names.push_back(make<NullChunk>(8));
579 
580     for (int I = 0, E = Syms.size(); I < E; ++I)
581       Syms[I]->setLocation(Addresses[Base + I]);
582     auto *MH = make<NullChunk>(8);
583     MH->Alignment = 8;
584     ModuleHandles.push_back(MH);
585 
586     // Fill the delay import table header fields.
587     Dir->ModuleHandle = MH;
588     Dir->AddressTab = Addresses[Base];
589     Dir->NameTab = Names[Base];
590     Dirs.push_back(Dir);
591   }
592   // Add null terminator.
593   Dirs.push_back(make<NullChunk>(sizeof(delay_import_directory_table_entry)));
594 }
595 
newThunkChunk(DefinedImportData * S,Chunk * Dir)596 Chunk *DelayLoadContents::newThunkChunk(DefinedImportData *S, Chunk *Dir) {
597   switch (Config->Machine) {
598   case AMD64:
599     return make<ThunkChunkX64>(S, Dir, Helper);
600   case I386:
601     return make<ThunkChunkX86>(S, Dir, Helper);
602   case ARMNT:
603     return make<ThunkChunkARM>(S, Dir, Helper);
604   case ARM64:
605     return make<ThunkChunkARM64>(S, Dir, Helper);
606   default:
607     llvm_unreachable("unsupported machine type");
608   }
609 }
610 
EdataContents()611 EdataContents::EdataContents() {
612   uint16_t MaxOrdinal = 0;
613   for (Export &E : Config->Exports)
614     MaxOrdinal = std::max(MaxOrdinal, E.Ordinal);
615 
616   auto *DLLName = make<StringChunk>(sys::path::filename(Config->OutputFile));
617   auto *AddressTab = make<AddressTableChunk>(MaxOrdinal);
618   std::vector<Chunk *> Names;
619   for (Export &E : Config->Exports)
620     if (!E.Noname)
621       Names.push_back(make<StringChunk>(E.ExportName));
622 
623   std::vector<Chunk *> Forwards;
624   for (Export &E : Config->Exports) {
625     if (E.ForwardTo.empty())
626       continue;
627     E.ForwardChunk = make<StringChunk>(E.ForwardTo);
628     Forwards.push_back(E.ForwardChunk);
629   }
630 
631   auto *NameTab = make<NamePointersChunk>(Names);
632   auto *OrdinalTab = make<ExportOrdinalChunk>(Names.size());
633   auto *Dir = make<ExportDirectoryChunk>(MaxOrdinal, Names.size(), DLLName,
634                                          AddressTab, NameTab, OrdinalTab);
635   Chunks.push_back(Dir);
636   Chunks.push_back(DLLName);
637   Chunks.push_back(AddressTab);
638   Chunks.push_back(NameTab);
639   Chunks.push_back(OrdinalTab);
640   Chunks.insert(Chunks.end(), Names.begin(), Names.end());
641   Chunks.insert(Chunks.end(), Forwards.begin(), Forwards.end());
642 }
643 
644 } // namespace coff
645 } // namespace lld
646