xref: /freebsd/contrib/llvm-project/lld/ELF/Arch/Hexagon.cpp (revision e64bea71c21eb42e97aa615188ba91f6cce0d36d)
1 //===-- Hexagon.cpp -------------------------------------------------------===//
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 "InputFiles.h"
10 #include "OutputSections.h"
11 #include "Symbols.h"
12 #include "SyntheticSections.h"
13 #include "Target.h"
14 #include "Thunks.h"
15 #include "lld/Common/ErrorHandler.h"
16 #include "llvm/ADT/SmallVector.h"
17 #include "llvm/BinaryFormat/ELF.h"
18 #include "llvm/Support/ELFAttributes.h"
19 #include "llvm/Support/Endian.h"
20 #include "llvm/Support/HexagonAttributeParser.h"
21 #include "llvm/Support/HexagonAttributes.h"
22 #include "llvm/Support/LEB128.h"
23 
24 using namespace llvm;
25 using namespace llvm::object;
26 using namespace llvm::support::endian;
27 using namespace llvm::ELF;
28 using namespace lld;
29 using namespace lld::elf;
30 
31 namespace {
32 class Hexagon final : public TargetInfo {
33 public:
34   Hexagon(Ctx &);
35   uint32_t calcEFlags() const override;
36   RelExpr getRelExpr(RelType type, const Symbol &s,
37                      const uint8_t *loc) const override;
38   RelType getDynRel(RelType type) const override;
39   int64_t getImplicitAddend(const uint8_t *buf, RelType type) const override;
40   bool needsThunk(RelExpr expr, RelType type, const InputFile *file,
41                   uint64_t branchAddr, const Symbol &s,
42                   int64_t a) const override;
43   bool inBranchRange(RelType type, uint64_t src, uint64_t dst) const override;
44   void relocate(uint8_t *loc, const Relocation &rel,
45                 uint64_t val) const override;
46   void writePltHeader(uint8_t *buf) const override;
47   void writePlt(uint8_t *buf, const Symbol &sym,
48                 uint64_t pltEntryAddr) const override;
49 };
50 } // namespace
51 
Hexagon(Ctx & ctx)52 Hexagon::Hexagon(Ctx &ctx) : TargetInfo(ctx) {
53   pltRel = R_HEX_JMP_SLOT;
54   relativeRel = R_HEX_RELATIVE;
55   gotRel = R_HEX_GLOB_DAT;
56   symbolicRel = R_HEX_32;
57 
58   gotBaseSymInGotPlt = true;
59   // The zero'th GOT entry is reserved for the address of _DYNAMIC.  The
60   // next 3 are reserved for the dynamic loader.
61   gotPltHeaderEntriesNum = 4;
62 
63   pltEntrySize = 16;
64   pltHeaderSize = 32;
65 
66   // Hexagon Linux uses 64K pages by default.
67   defaultMaxPageSize = 0x10000;
68   tlsGotRel = R_HEX_TPREL_32;
69   tlsModuleIndexRel = R_HEX_DTPMOD_32;
70   tlsOffsetRel = R_HEX_DTPREL_32;
71 
72   needsThunks = true;
73 }
74 
calcEFlags() const75 uint32_t Hexagon::calcEFlags() const {
76   // The architecture revision must always be equal to or greater than
77   // greatest revision in the list of inputs.
78   std::optional<uint32_t> ret;
79   for (InputFile *f : ctx.objectFiles) {
80     uint32_t eflags = cast<ObjFile<ELF32LE>>(f)->getObj().getHeader().e_flags;
81     if (!ret || eflags > *ret)
82       ret = eflags;
83   }
84   return ret.value_or(/* Default Arch Rev: */ EF_HEXAGON_MACH_V68);
85 }
86 
applyMask(uint32_t mask,uint32_t data)87 static uint32_t applyMask(uint32_t mask, uint32_t data) {
88   uint32_t result = 0;
89   size_t off = 0;
90 
91   for (size_t bit = 0; bit != 32; ++bit) {
92     uint32_t valBit = (data >> off) & 1;
93     uint32_t maskBit = (mask >> bit) & 1;
94     if (maskBit) {
95       result |= (valBit << bit);
96       ++off;
97     }
98   }
99   return result;
100 }
101 
getRelExpr(RelType type,const Symbol & s,const uint8_t * loc) const102 RelExpr Hexagon::getRelExpr(RelType type, const Symbol &s,
103                             const uint8_t *loc) const {
104   switch (type) {
105   case R_HEX_NONE:
106     return R_NONE;
107   case R_HEX_6_X:
108   case R_HEX_8_X:
109   case R_HEX_9_X:
110   case R_HEX_10_X:
111   case R_HEX_11_X:
112   case R_HEX_12_X:
113   case R_HEX_16_X:
114   case R_HEX_32:
115   case R_HEX_32_6_X:
116   case R_HEX_HI16:
117   case R_HEX_LO16:
118   case R_HEX_DTPREL_32:
119     return R_ABS;
120   case R_HEX_B9_PCREL:
121   case R_HEX_B13_PCREL:
122   case R_HEX_B15_PCREL:
123   case R_HEX_6_PCREL_X:
124   case R_HEX_32_PCREL:
125     return R_PC;
126   case R_HEX_B9_PCREL_X:
127   case R_HEX_B15_PCREL_X:
128   case R_HEX_B22_PCREL:
129   case R_HEX_PLT_B22_PCREL:
130   case R_HEX_B22_PCREL_X:
131   case R_HEX_B32_PCREL_X:
132   case R_HEX_GD_PLT_B22_PCREL:
133   case R_HEX_GD_PLT_B22_PCREL_X:
134   case R_HEX_GD_PLT_B32_PCREL_X:
135     return R_PLT_PC;
136   case R_HEX_IE_32_6_X:
137   case R_HEX_IE_16_X:
138   case R_HEX_IE_HI16:
139   case R_HEX_IE_LO16:
140     return R_GOT;
141   case R_HEX_GD_GOT_11_X:
142   case R_HEX_GD_GOT_16_X:
143   case R_HEX_GD_GOT_32_6_X:
144     return R_TLSGD_GOTPLT;
145   case R_HEX_GOTREL_11_X:
146   case R_HEX_GOTREL_16_X:
147   case R_HEX_GOTREL_32_6_X:
148   case R_HEX_GOTREL_HI16:
149   case R_HEX_GOTREL_LO16:
150     return R_GOTPLTREL;
151   case R_HEX_GOT_11_X:
152   case R_HEX_GOT_16_X:
153   case R_HEX_GOT_32_6_X:
154     return R_GOTPLT;
155   case R_HEX_IE_GOT_11_X:
156   case R_HEX_IE_GOT_16_X:
157   case R_HEX_IE_GOT_32_6_X:
158   case R_HEX_IE_GOT_HI16:
159   case R_HEX_IE_GOT_LO16:
160     return R_GOTPLT;
161   case R_HEX_TPREL_11_X:
162   case R_HEX_TPREL_16:
163   case R_HEX_TPREL_16_X:
164   case R_HEX_TPREL_32_6_X:
165   case R_HEX_TPREL_HI16:
166   case R_HEX_TPREL_LO16:
167     return R_TPREL;
168   default:
169     Err(ctx) << getErrorLoc(ctx, loc) << "unknown relocation (" << type.v
170              << ") against symbol " << &s;
171     return R_NONE;
172   }
173 }
174 
175 // There are (arguably too) many relocation masks for the DSP's
176 // R_HEX_6_X type.  The table below is used to select the correct mask
177 // for the given instruction.
178 struct InstructionMask {
179   uint32_t cmpMask;
180   uint32_t relocMask;
181 };
182 static const InstructionMask r6[] = {
183     {0x38000000, 0x0000201f}, {0x39000000, 0x0000201f},
184     {0x3e000000, 0x00001f80}, {0x3f000000, 0x00001f80},
185     {0x40000000, 0x000020f8}, {0x41000000, 0x000007e0},
186     {0x42000000, 0x000020f8}, {0x43000000, 0x000007e0},
187     {0x44000000, 0x000020f8}, {0x45000000, 0x000007e0},
188     {0x46000000, 0x000020f8}, {0x47000000, 0x000007e0},
189     {0x6a000000, 0x00001f80}, {0x7c000000, 0x001f2000},
190     {0x9a000000, 0x00000f60}, {0x9b000000, 0x00000f60},
191     {0x9c000000, 0x00000f60}, {0x9d000000, 0x00000f60},
192     {0x9f000000, 0x001f0100}, {0xab000000, 0x0000003f},
193     {0xad000000, 0x0000003f}, {0xaf000000, 0x00030078},
194     {0xd7000000, 0x006020e0}, {0xd8000000, 0x006020e0},
195     {0xdb000000, 0x006020e0}, {0xdf000000, 0x006020e0}};
196 
197 constexpr uint32_t instParsePacketEnd = 0x0000c000;
198 
isDuplex(uint32_t insn)199 static bool isDuplex(uint32_t insn) {
200   // Duplex forms have a fixed mask and parse bits 15:14 are always
201   // zero.  Non-duplex insns will always have at least one bit set in the
202   // parse field.
203   return (instParsePacketEnd & insn) == 0;
204 }
205 
findMaskR6(Ctx & ctx,uint32_t insn)206 static uint32_t findMaskR6(Ctx &ctx, uint32_t insn) {
207   if (isDuplex(insn))
208     return 0x03f00000;
209 
210   for (InstructionMask i : r6)
211     if ((0xff000000 & insn) == i.cmpMask)
212       return i.relocMask;
213 
214   Err(ctx) << "unrecognized instruction for 6_X relocation: 0x"
215            << utohexstr(insn, true);
216   return 0;
217 }
218 
findMaskR8(uint32_t insn)219 static uint32_t findMaskR8(uint32_t insn) {
220   if ((0xff000000 & insn) == 0xde000000)
221     return 0x00e020e8;
222   if ((0xff000000 & insn) == 0x3c000000)
223     return 0x0000207f;
224   return 0x00001fe0;
225 }
226 
findMaskR11(uint32_t insn)227 static uint32_t findMaskR11(uint32_t insn) {
228   if ((0xff000000 & insn) == 0xa1000000)
229     return 0x060020ff;
230   return 0x06003fe0;
231 }
232 
findMaskR16(Ctx & ctx,uint32_t insn)233 static uint32_t findMaskR16(Ctx &ctx, uint32_t insn) {
234   if (isDuplex(insn))
235     return 0x03f00000;
236 
237   // Clear the end-packet-parse bits:
238   insn = insn & ~instParsePacketEnd;
239 
240   if ((0xff000000 & insn) == 0x48000000)
241     return 0x061f20ff;
242   if ((0xff000000 & insn) == 0x49000000)
243     return 0x061f3fe0;
244   if ((0xff000000 & insn) == 0x78000000)
245     return 0x00df3fe0;
246   if ((0xff000000 & insn) == 0xb0000000)
247     return 0x0fe03fe0;
248 
249   if ((0xff802000 & insn) == 0x74000000)
250     return 0x00001fe0;
251   if ((0xff802000 & insn) == 0x74002000)
252     return 0x00001fe0;
253   if ((0xff802000 & insn) == 0x74800000)
254     return 0x00001fe0;
255   if ((0xff802000 & insn) == 0x74802000)
256     return 0x00001fe0;
257 
258   for (InstructionMask i : r6)
259     if ((0xff000000 & insn) == i.cmpMask)
260       return i.relocMask;
261 
262   Err(ctx) << "unrecognized instruction for 16_X type: 0x" << utohexstr(insn);
263   return 0;
264 }
265 
or32le(uint8_t * p,int32_t v)266 static void or32le(uint8_t *p, int32_t v) { write32le(p, read32le(p) | v); }
267 
inBranchRange(RelType type,uint64_t src,uint64_t dst) const268 bool Hexagon::inBranchRange(RelType type, uint64_t src, uint64_t dst) const {
269   int64_t offset = dst - src;
270   switch (type) {
271   case llvm::ELF::R_HEX_B22_PCREL:
272   case llvm::ELF::R_HEX_PLT_B22_PCREL:
273   case llvm::ELF::R_HEX_GD_PLT_B22_PCREL:
274   case llvm::ELF::R_HEX_LD_PLT_B22_PCREL:
275     return llvm::isInt<22>(offset >> 2);
276   case llvm::ELF::R_HEX_B15_PCREL:
277     return llvm::isInt<15>(offset >> 2);
278     break;
279   case llvm::ELF::R_HEX_B13_PCREL:
280     return llvm::isInt<13>(offset >> 2);
281     break;
282   case llvm::ELF::R_HEX_B9_PCREL:
283     return llvm::isInt<9>(offset >> 2);
284   default:
285     return true;
286   }
287   llvm_unreachable("unsupported relocation");
288 }
289 
needsThunk(RelExpr expr,RelType type,const InputFile * file,uint64_t branchAddr,const Symbol & s,int64_t a) const290 bool Hexagon::needsThunk(RelExpr expr, RelType type, const InputFile *file,
291                          uint64_t branchAddr, const Symbol &s,
292                          int64_t a) const {
293   // Only check branch range for supported branch relocation types
294   switch (type) {
295   case R_HEX_B22_PCREL:
296   case R_HEX_PLT_B22_PCREL:
297   case R_HEX_GD_PLT_B22_PCREL:
298   case R_HEX_LD_PLT_B22_PCREL:
299   case R_HEX_B15_PCREL:
300   case R_HEX_B13_PCREL:
301   case R_HEX_B9_PCREL:
302     return !ctx.target->inBranchRange(type, branchAddr, s.getVA(ctx, a));
303   default:
304     return false;
305   }
306 }
307 
relocate(uint8_t * loc,const Relocation & rel,uint64_t val) const308 void Hexagon::relocate(uint8_t *loc, const Relocation &rel,
309                        uint64_t val) const {
310   switch (rel.type) {
311   case R_HEX_NONE:
312     break;
313   case R_HEX_6_PCREL_X:
314   case R_HEX_6_X:
315     or32le(loc, applyMask(findMaskR6(ctx, read32le(loc)), val));
316     break;
317   case R_HEX_8_X:
318     or32le(loc, applyMask(findMaskR8(read32le(loc)), val));
319     break;
320   case R_HEX_9_X:
321     or32le(loc, applyMask(0x00003fe0, val & 0x3f));
322     break;
323   case R_HEX_10_X:
324     or32le(loc, applyMask(0x00203fe0, val & 0x3f));
325     break;
326   case R_HEX_11_X:
327   case R_HEX_GD_GOT_11_X:
328   case R_HEX_IE_GOT_11_X:
329   case R_HEX_GOT_11_X:
330   case R_HEX_GOTREL_11_X:
331   case R_HEX_TPREL_11_X:
332     or32le(loc, applyMask(findMaskR11(read32le(loc)), val & 0x3f));
333     break;
334   case R_HEX_12_X:
335     or32le(loc, applyMask(0x000007e0, val));
336     break;
337   case R_HEX_16_X: // These relocs only have 6 effective bits.
338   case R_HEX_IE_16_X:
339   case R_HEX_IE_GOT_16_X:
340   case R_HEX_GD_GOT_16_X:
341   case R_HEX_GOT_16_X:
342   case R_HEX_GOTREL_16_X:
343   case R_HEX_TPREL_16_X:
344     or32le(loc, applyMask(findMaskR16(ctx, read32le(loc)), val & 0x3f));
345     break;
346   case R_HEX_TPREL_16:
347     or32le(loc, applyMask(findMaskR16(ctx, read32le(loc)), val & 0xffff));
348     break;
349   case R_HEX_32:
350   case R_HEX_32_PCREL:
351   case R_HEX_DTPREL_32:
352     or32le(loc, val);
353     break;
354   case R_HEX_32_6_X:
355   case R_HEX_GD_GOT_32_6_X:
356   case R_HEX_GOT_32_6_X:
357   case R_HEX_GOTREL_32_6_X:
358   case R_HEX_IE_GOT_32_6_X:
359   case R_HEX_IE_32_6_X:
360   case R_HEX_TPREL_32_6_X:
361     or32le(loc, applyMask(0x0fff3fff, val >> 6));
362     break;
363   case R_HEX_B9_PCREL:
364     checkInt(ctx, loc, val, 11, rel);
365     or32le(loc, applyMask(0x003000fe, val >> 2));
366     break;
367   case R_HEX_B9_PCREL_X:
368     or32le(loc, applyMask(0x003000fe, val & 0x3f));
369     break;
370   case R_HEX_B13_PCREL:
371     checkInt(ctx, loc, val, 15, rel);
372     or32le(loc, applyMask(0x00202ffe, val >> 2));
373     break;
374   case R_HEX_B15_PCREL:
375     checkInt(ctx, loc, val, 17, rel);
376     or32le(loc, applyMask(0x00df20fe, val >> 2));
377     break;
378   case R_HEX_B15_PCREL_X:
379     or32le(loc, applyMask(0x00df20fe, val & 0x3f));
380     break;
381   case R_HEX_B22_PCREL:
382   case R_HEX_GD_PLT_B22_PCREL:
383   case R_HEX_PLT_B22_PCREL:
384     checkInt(ctx, loc, val, 24, rel);
385     or32le(loc, applyMask(0x1ff3ffe, val >> 2));
386     break;
387   case R_HEX_B22_PCREL_X:
388   case R_HEX_GD_PLT_B22_PCREL_X:
389     or32le(loc, applyMask(0x1ff3ffe, val & 0x3f));
390     break;
391   case R_HEX_B32_PCREL_X:
392   case R_HEX_GD_PLT_B32_PCREL_X:
393     or32le(loc, applyMask(0x0fff3fff, val >> 6));
394     break;
395   case R_HEX_GOTREL_HI16:
396   case R_HEX_HI16:
397   case R_HEX_IE_GOT_HI16:
398   case R_HEX_IE_HI16:
399   case R_HEX_TPREL_HI16:
400     or32le(loc, applyMask(0x00c03fff, val >> 16));
401     break;
402   case R_HEX_GOTREL_LO16:
403   case R_HEX_LO16:
404   case R_HEX_IE_GOT_LO16:
405   case R_HEX_IE_LO16:
406   case R_HEX_TPREL_LO16:
407     or32le(loc, applyMask(0x00c03fff, val));
408     break;
409   default:
410     llvm_unreachable("unknown relocation");
411   }
412 }
413 
writePltHeader(uint8_t * buf) const414 void Hexagon::writePltHeader(uint8_t *buf) const {
415   const uint8_t pltData[] = {
416       0x00, 0x40, 0x00, 0x00, // { immext (#0)
417       0x1c, 0xc0, 0x49, 0x6a, //   r28 = add (pc, ##GOT0@PCREL) } # @GOT0
418       0x0e, 0x42, 0x9c, 0xe2, // { r14 -= add (r28, #16)  # offset of GOTn
419       0x4f, 0x40, 0x9c, 0x91, //   r15 = memw (r28 + #8)  # object ID at GOT2
420       0x3c, 0xc0, 0x9c, 0x91, //   r28 = memw (r28 + #4) }# dynamic link at GOT1
421       0x0e, 0x42, 0x0e, 0x8c, // { r14 = asr (r14, #2)    # index of PLTn
422       0x00, 0xc0, 0x9c, 0x52, //   jumpr r28 }            # call dynamic linker
423       0x0c, 0xdb, 0x00, 0x54, // trap0(#0xdb) # bring plt0 into 16byte alignment
424   };
425   memcpy(buf, pltData, sizeof(pltData));
426 
427   // Offset from PLT0 to the GOT.
428   uint64_t off = ctx.in.gotPlt->getVA() - ctx.in.plt->getVA();
429   relocateNoSym(buf, R_HEX_B32_PCREL_X, off);
430   relocateNoSym(buf + 4, R_HEX_6_PCREL_X, off);
431 }
432 
writePlt(uint8_t * buf,const Symbol & sym,uint64_t pltEntryAddr) const433 void Hexagon::writePlt(uint8_t *buf, const Symbol &sym,
434                        uint64_t pltEntryAddr) const {
435   const uint8_t inst[] = {
436       0x00, 0x40, 0x00, 0x00, // { immext (#0)
437       0x0e, 0xc0, 0x49, 0x6a, //   r14 = add (pc, ##GOTn@PCREL) }
438       0x1c, 0xc0, 0x8e, 0x91, // r28 = memw (r14)
439       0x00, 0xc0, 0x9c, 0x52, // jumpr r28
440   };
441   memcpy(buf, inst, sizeof(inst));
442 
443   uint64_t gotPltEntryAddr = sym.getGotPltVA(ctx);
444   relocateNoSym(buf, R_HEX_B32_PCREL_X, gotPltEntryAddr - pltEntryAddr);
445   relocateNoSym(buf + 4, R_HEX_6_PCREL_X, gotPltEntryAddr - pltEntryAddr);
446 }
447 
getDynRel(RelType type) const448 RelType Hexagon::getDynRel(RelType type) const {
449   if (type == R_HEX_32)
450     return type;
451   return R_HEX_NONE;
452 }
453 
getImplicitAddend(const uint8_t * buf,RelType type) const454 int64_t Hexagon::getImplicitAddend(const uint8_t *buf, RelType type) const {
455   switch (type) {
456   case R_HEX_NONE:
457   case R_HEX_GLOB_DAT:
458   case R_HEX_JMP_SLOT:
459     return 0;
460   case R_HEX_32:
461   case R_HEX_RELATIVE:
462   case R_HEX_DTPMOD_32:
463   case R_HEX_DTPREL_32:
464   case R_HEX_TPREL_32:
465     return SignExtend64<32>(read32(ctx, buf));
466   default:
467     InternalErr(ctx, buf) << "cannot read addend for relocation " << type;
468     return 0;
469   }
470 }
471 
472 namespace {
473 class HexagonAttributesSection final : public SyntheticSection {
474 public:
HexagonAttributesSection(Ctx & ctx)475   HexagonAttributesSection(Ctx &ctx)
476       : SyntheticSection(ctx, ".hexagon.attributes", SHT_HEXAGON_ATTRIBUTES, 0,
477                          1) {}
478 
getSize() const479   size_t getSize() const override { return size; }
480   void writeTo(uint8_t *buf) override;
481 
482   static constexpr StringRef vendor = "hexagon";
483   DenseMap<unsigned, unsigned> intAttr;
484   size_t size = 0;
485 };
486 } // namespace
487 
488 static HexagonAttributesSection *
mergeAttributesSection(Ctx & ctx,const SmallVector<InputSectionBase *,0> & sections)489 mergeAttributesSection(Ctx &ctx,
490                        const SmallVector<InputSectionBase *, 0> &sections) {
491   ctx.in.hexagonAttributes = std::make_unique<HexagonAttributesSection>(ctx);
492   auto &merged =
493       static_cast<HexagonAttributesSection &>(*ctx.in.hexagonAttributes);
494 
495   // Collect all tags values from attributes section.
496   const auto &attributesTags = HexagonAttrs::getHexagonAttributeTags();
497   for (const InputSectionBase *sec : sections) {
498     HexagonAttributeParser parser;
499     if (Error e = parser.parse(sec->content(), llvm::endianness::little))
500       Warn(ctx) << sec << ": " << std::move(e);
501     for (const auto &tag : attributesTags) {
502       switch (HexagonAttrs::AttrType(tag.attr)) {
503       case HexagonAttrs::ARCH:
504       case HexagonAttrs::HVXARCH:
505         if (auto i = parser.getAttributeValue(tag.attr)) {
506           auto r = merged.intAttr.try_emplace(tag.attr, *i);
507           if (!r.second)
508             if (r.first->second < *i)
509               r.first->second = *i;
510         }
511         continue;
512 
513       case HexagonAttrs::HVXIEEEFP:
514       case HexagonAttrs::HVXQFLOAT:
515       case HexagonAttrs::ZREG:
516       case HexagonAttrs::AUDIO:
517       case HexagonAttrs::CABAC:
518         if (auto i = parser.getAttributeValue(tag.attr)) {
519           auto r = merged.intAttr.try_emplace(tag.attr, *i);
520           if (!r.second && r.first->second != *i) {
521             r.first->second |= *i;
522           }
523         }
524         continue;
525       }
526     }
527   }
528 
529   // The total size of headers: format-version [ <section-length> "vendor-name"
530   // [ <file-tag> <size>.
531   size_t size = 5 + merged.vendor.size() + 1 + 5;
532   for (auto &attr : merged.intAttr)
533     if (attr.second != 0)
534       size += getULEB128Size(attr.first) + getULEB128Size(attr.second);
535   merged.size = size;
536   return &merged;
537 }
538 
writeTo(uint8_t * buf)539 void HexagonAttributesSection::writeTo(uint8_t *buf) {
540   const size_t size = getSize();
541   uint8_t *const end = buf + size;
542   *buf = ELFAttrs::Format_Version;
543   write32(ctx, buf + 1, size - 1);
544   buf += 5;
545 
546   memcpy(buf, vendor.data(), vendor.size());
547   buf += vendor.size() + 1;
548 
549   *buf = ELFAttrs::File;
550   write32(ctx, buf + 1, end - buf);
551   buf += 5;
552 
553   for (auto &attr : intAttr) {
554     if (attr.second == 0)
555       continue;
556     buf += encodeULEB128(attr.first, buf);
557     buf += encodeULEB128(attr.second, buf);
558   }
559 }
560 
mergeHexagonAttributesSections(Ctx & ctx)561 void elf::mergeHexagonAttributesSections(Ctx &ctx) {
562   // Find the first input SHT_HEXAGON_ATTRIBUTES; return if not found.
563   size_t place =
564       llvm::find_if(ctx.inputSections,
565                     [](auto *s) { return s->type == SHT_HEXAGON_ATTRIBUTES; }) -
566       ctx.inputSections.begin();
567   if (place == ctx.inputSections.size())
568     return;
569 
570   // Extract all SHT_HEXAGON_ATTRIBUTES sections into `sections`.
571   SmallVector<InputSectionBase *, 0> sections;
572   llvm::erase_if(ctx.inputSections, [&](InputSectionBase *s) {
573     if (s->type != SHT_HEXAGON_ATTRIBUTES)
574       return false;
575     sections.push_back(s);
576     return true;
577   });
578 
579   // Add the merged section.
580   ctx.inputSections.insert(ctx.inputSections.begin() + place,
581                            mergeAttributesSection(ctx, sections));
582 }
583 
setHexagonTargetInfo(Ctx & ctx)584 void elf::setHexagonTargetInfo(Ctx &ctx) { ctx.target.reset(new Hexagon(ctx)); }
585