1// Copyright 2010 The Go Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style 3// license that can be found in the LICENSE file. 4 5// Package loadpe implements a PE/COFF file reader. 6package loadpe 7 8import ( 9 "bytes" 10 "cmd/internal/bio" 11 "cmd/internal/objabi" 12 "cmd/internal/sys" 13 "cmd/link/internal/loader" 14 "cmd/link/internal/sym" 15 "debug/pe" 16 "encoding/binary" 17 "errors" 18 "fmt" 19 "io" 20 "strings" 21) 22 23const ( 24 // TODO: the Microsoft doco says IMAGE_SYM_DTYPE_ARRAY is 3 (same with IMAGE_SYM_DTYPE_POINTER and IMAGE_SYM_DTYPE_FUNCTION) 25 IMAGE_SYM_UNDEFINED = 0 26 IMAGE_SYM_ABSOLUTE = -1 27 IMAGE_SYM_DEBUG = -2 28 IMAGE_SYM_TYPE_NULL = 0 29 IMAGE_SYM_TYPE_VOID = 1 30 IMAGE_SYM_TYPE_CHAR = 2 31 IMAGE_SYM_TYPE_SHORT = 3 32 IMAGE_SYM_TYPE_INT = 4 33 IMAGE_SYM_TYPE_LONG = 5 34 IMAGE_SYM_TYPE_FLOAT = 6 35 IMAGE_SYM_TYPE_DOUBLE = 7 36 IMAGE_SYM_TYPE_STRUCT = 8 37 IMAGE_SYM_TYPE_UNION = 9 38 IMAGE_SYM_TYPE_ENUM = 10 39 IMAGE_SYM_TYPE_MOE = 11 40 IMAGE_SYM_TYPE_BYTE = 12 41 IMAGE_SYM_TYPE_WORD = 13 42 IMAGE_SYM_TYPE_UINT = 14 43 IMAGE_SYM_TYPE_DWORD = 15 44 IMAGE_SYM_TYPE_PCODE = 32768 45 IMAGE_SYM_DTYPE_NULL = 0 46 IMAGE_SYM_DTYPE_POINTER = 0x10 47 IMAGE_SYM_DTYPE_FUNCTION = 0x20 48 IMAGE_SYM_DTYPE_ARRAY = 0x30 49 IMAGE_SYM_CLASS_END_OF_FUNCTION = -1 50 IMAGE_SYM_CLASS_NULL = 0 51 IMAGE_SYM_CLASS_AUTOMATIC = 1 52 IMAGE_SYM_CLASS_EXTERNAL = 2 53 IMAGE_SYM_CLASS_STATIC = 3 54 IMAGE_SYM_CLASS_REGISTER = 4 55 IMAGE_SYM_CLASS_EXTERNAL_DEF = 5 56 IMAGE_SYM_CLASS_LABEL = 6 57 IMAGE_SYM_CLASS_UNDEFINED_LABEL = 7 58 IMAGE_SYM_CLASS_MEMBER_OF_STRUCT = 8 59 IMAGE_SYM_CLASS_ARGUMENT = 9 60 IMAGE_SYM_CLASS_STRUCT_TAG = 10 61 IMAGE_SYM_CLASS_MEMBER_OF_UNION = 11 62 IMAGE_SYM_CLASS_UNION_TAG = 12 63 IMAGE_SYM_CLASS_TYPE_DEFINITION = 13 64 IMAGE_SYM_CLASS_UNDEFINED_STATIC = 14 65 IMAGE_SYM_CLASS_ENUM_TAG = 15 66 IMAGE_SYM_CLASS_MEMBER_OF_ENUM = 16 67 IMAGE_SYM_CLASS_REGISTER_PARAM = 17 68 IMAGE_SYM_CLASS_BIT_FIELD = 18 69 IMAGE_SYM_CLASS_FAR_EXTERNAL = 68 /* Not in PECOFF v8 spec */ 70 IMAGE_SYM_CLASS_BLOCK = 100 71 IMAGE_SYM_CLASS_FUNCTION = 101 72 IMAGE_SYM_CLASS_END_OF_STRUCT = 102 73 IMAGE_SYM_CLASS_FILE = 103 74 IMAGE_SYM_CLASS_SECTION = 104 75 IMAGE_SYM_CLASS_WEAK_EXTERNAL = 105 76 IMAGE_SYM_CLASS_CLR_TOKEN = 107 77 IMAGE_REL_I386_ABSOLUTE = 0x0000 78 IMAGE_REL_I386_DIR16 = 0x0001 79 IMAGE_REL_I386_REL16 = 0x0002 80 IMAGE_REL_I386_DIR32 = 0x0006 81 IMAGE_REL_I386_DIR32NB = 0x0007 82 IMAGE_REL_I386_SEG12 = 0x0009 83 IMAGE_REL_I386_SECTION = 0x000A 84 IMAGE_REL_I386_SECREL = 0x000B 85 IMAGE_REL_I386_TOKEN = 0x000C 86 IMAGE_REL_I386_SECREL7 = 0x000D 87 IMAGE_REL_I386_REL32 = 0x0014 88 IMAGE_REL_AMD64_ABSOLUTE = 0x0000 89 IMAGE_REL_AMD64_ADDR64 = 0x0001 90 IMAGE_REL_AMD64_ADDR32 = 0x0002 91 IMAGE_REL_AMD64_ADDR32NB = 0x0003 92 IMAGE_REL_AMD64_REL32 = 0x0004 93 IMAGE_REL_AMD64_REL32_1 = 0x0005 94 IMAGE_REL_AMD64_REL32_2 = 0x0006 95 IMAGE_REL_AMD64_REL32_3 = 0x0007 96 IMAGE_REL_AMD64_REL32_4 = 0x0008 97 IMAGE_REL_AMD64_REL32_5 = 0x0009 98 IMAGE_REL_AMD64_SECTION = 0x000A 99 IMAGE_REL_AMD64_SECREL = 0x000B 100 IMAGE_REL_AMD64_SECREL7 = 0x000C 101 IMAGE_REL_AMD64_TOKEN = 0x000D 102 IMAGE_REL_AMD64_SREL32 = 0x000E 103 IMAGE_REL_AMD64_PAIR = 0x000F 104 IMAGE_REL_AMD64_SSPAN32 = 0x0010 105 IMAGE_REL_ARM_ABSOLUTE = 0x0000 106 IMAGE_REL_ARM_ADDR32 = 0x0001 107 IMAGE_REL_ARM_ADDR32NB = 0x0002 108 IMAGE_REL_ARM_BRANCH24 = 0x0003 109 IMAGE_REL_ARM_BRANCH11 = 0x0004 110 IMAGE_REL_ARM_SECTION = 0x000E 111 IMAGE_REL_ARM_SECREL = 0x000F 112 IMAGE_REL_ARM_MOV32 = 0x0010 113 IMAGE_REL_THUMB_MOV32 = 0x0011 114 IMAGE_REL_THUMB_BRANCH20 = 0x0012 115 IMAGE_REL_THUMB_BRANCH24 = 0x0014 116 IMAGE_REL_THUMB_BLX23 = 0x0015 117 IMAGE_REL_ARM_PAIR = 0x0016 118 IMAGE_REL_ARM64_ABSOLUTE = 0x0000 119 IMAGE_REL_ARM64_ADDR32 = 0x0001 120 IMAGE_REL_ARM64_ADDR32NB = 0x0002 121 IMAGE_REL_ARM64_BRANCH26 = 0x0003 122 IMAGE_REL_ARM64_PAGEBASE_REL21 = 0x0004 123 IMAGE_REL_ARM64_REL21 = 0x0005 124 IMAGE_REL_ARM64_PAGEOFFSET_12A = 0x0006 125 IMAGE_REL_ARM64_PAGEOFFSET_12L = 0x0007 126 IMAGE_REL_ARM64_SECREL = 0x0008 127 IMAGE_REL_ARM64_SECREL_LOW12A = 0x0009 128 IMAGE_REL_ARM64_SECREL_HIGH12A = 0x000A 129 IMAGE_REL_ARM64_SECREL_LOW12L = 0x000B 130 IMAGE_REL_ARM64_TOKEN = 0x000C 131 IMAGE_REL_ARM64_SECTION = 0x000D 132 IMAGE_REL_ARM64_ADDR64 = 0x000E 133 IMAGE_REL_ARM64_BRANCH19 = 0x000F 134 IMAGE_REL_ARM64_BRANCH14 = 0x0010 135 IMAGE_REL_ARM64_REL32 = 0x0011 136) 137 138// TODO(crawshaw): de-duplicate these symbols with cmd/internal/ld, ideally in debug/pe. 139const ( 140 IMAGE_SCN_CNT_CODE = 0x00000020 141 IMAGE_SCN_CNT_INITIALIZED_DATA = 0x00000040 142 IMAGE_SCN_CNT_UNINITIALIZED_DATA = 0x00000080 143 IMAGE_SCN_MEM_DISCARDABLE = 0x02000000 144 IMAGE_SCN_MEM_EXECUTE = 0x20000000 145 IMAGE_SCN_MEM_READ = 0x40000000 146 IMAGE_SCN_MEM_WRITE = 0x80000000 147) 148 149// TODO(brainman): maybe just add ReadAt method to bio.Reader instead of creating peBiobuf 150 151// peBiobuf makes bio.Reader look like io.ReaderAt. 152type peBiobuf bio.Reader 153 154func (f *peBiobuf) ReadAt(p []byte, off int64) (int, error) { 155 ret := ((*bio.Reader)(f)).MustSeek(off, 0) 156 if ret < 0 { 157 return 0, errors.New("fail to seek") 158 } 159 n, err := f.Read(p) 160 if err != nil { 161 return 0, err 162 } 163 return n, nil 164} 165 166// makeUpdater creates a loader.SymbolBuilder if one hasn't been created previously. 167// We use this to lazily make SymbolBuilders as we don't always need a builder, and creating them for all symbols might be an error. 168func makeUpdater(l *loader.Loader, bld *loader.SymbolBuilder, s loader.Sym) *loader.SymbolBuilder { 169 if bld != nil { 170 return bld 171 } 172 bld = l.MakeSymbolUpdater(s) 173 return bld 174} 175 176// Load loads the PE file pn from input. 177// Symbols are written into syms, and a slice of the text symbols is returned. 178// If an .rsrc section or set of .rsrc$xx sections is found, its symbols are 179// returned as rsrc. 180func Load(l *loader.Loader, arch *sys.Arch, localSymVersion int, input *bio.Reader, pkg string, length int64, pn string) (textp []loader.Sym, rsrc []loader.Sym, err error) { 181 lookup := l.LookupOrCreateCgoExport 182 sectsyms := make(map[*pe.Section]loader.Sym) 183 sectdata := make(map[*pe.Section][]byte) 184 185 // Some input files are archives containing multiple of 186 // object files, and pe.NewFile seeks to the start of 187 // input file and get confused. Create section reader 188 // to stop pe.NewFile looking before current position. 189 sr := io.NewSectionReader((*peBiobuf)(input), input.Offset(), 1<<63-1) 190 191 // TODO: replace pe.NewFile with pe.Load (grep for "add Load function" in debug/pe for details) 192 f, err := pe.NewFile(sr) 193 if err != nil { 194 return nil, nil, err 195 } 196 defer f.Close() 197 198 // TODO return error if found .cormeta 199 200 // create symbols for mapped sections 201 for _, sect := range f.Sections { 202 if sect.Characteristics&IMAGE_SCN_MEM_DISCARDABLE != 0 { 203 continue 204 } 205 206 if sect.Characteristics&(IMAGE_SCN_CNT_CODE|IMAGE_SCN_CNT_INITIALIZED_DATA|IMAGE_SCN_CNT_UNINITIALIZED_DATA) == 0 { 207 // This has been seen for .idata sections, which we 208 // want to ignore. See issues 5106 and 5273. 209 continue 210 } 211 212 name := fmt.Sprintf("%s(%s)", pkg, sect.Name) 213 s := lookup(name, localSymVersion) 214 bld := l.MakeSymbolUpdater(s) 215 216 switch sect.Characteristics & (IMAGE_SCN_CNT_UNINITIALIZED_DATA | IMAGE_SCN_CNT_INITIALIZED_DATA | IMAGE_SCN_MEM_READ | IMAGE_SCN_MEM_WRITE | IMAGE_SCN_CNT_CODE | IMAGE_SCN_MEM_EXECUTE) { 217 case IMAGE_SCN_CNT_INITIALIZED_DATA | IMAGE_SCN_MEM_READ: //.rdata 218 bld.SetType(sym.SRODATA) 219 220 case IMAGE_SCN_CNT_UNINITIALIZED_DATA | IMAGE_SCN_MEM_READ | IMAGE_SCN_MEM_WRITE: //.bss 221 bld.SetType(sym.SNOPTRBSS) 222 223 case IMAGE_SCN_CNT_INITIALIZED_DATA | IMAGE_SCN_MEM_READ | IMAGE_SCN_MEM_WRITE: //.data 224 bld.SetType(sym.SNOPTRDATA) 225 226 case IMAGE_SCN_CNT_CODE | IMAGE_SCN_MEM_EXECUTE | IMAGE_SCN_MEM_READ: //.text 227 bld.SetType(sym.STEXT) 228 229 default: 230 return nil, nil, fmt.Errorf("unexpected flags %#06x for PE section %s", sect.Characteristics, sect.Name) 231 } 232 233 if bld.Type() != sym.SNOPTRBSS { 234 data, err := sect.Data() 235 if err != nil { 236 return nil, nil, err 237 } 238 sectdata[sect] = data 239 bld.SetData(data) 240 } 241 bld.SetSize(int64(sect.Size)) 242 sectsyms[sect] = s 243 if sect.Name == ".rsrc" || strings.HasPrefix(sect.Name, ".rsrc$") { 244 rsrc = append(rsrc, s) 245 } 246 } 247 248 // load relocations 249 for _, rsect := range f.Sections { 250 if _, found := sectsyms[rsect]; !found { 251 continue 252 } 253 if rsect.NumberOfRelocations == 0 { 254 continue 255 } 256 if rsect.Characteristics&IMAGE_SCN_MEM_DISCARDABLE != 0 { 257 continue 258 } 259 if rsect.Characteristics&(IMAGE_SCN_CNT_CODE|IMAGE_SCN_CNT_INITIALIZED_DATA|IMAGE_SCN_CNT_UNINITIALIZED_DATA) == 0 { 260 // This has been seen for .idata sections, which we 261 // want to ignore. See issues 5106 and 5273. 262 continue 263 } 264 265 splitResources := strings.HasPrefix(rsect.Name, ".rsrc$") 266 sb := l.MakeSymbolUpdater(sectsyms[rsect]) 267 for j, r := range rsect.Relocs { 268 if int(r.SymbolTableIndex) >= len(f.COFFSymbols) { 269 return nil, nil, fmt.Errorf("relocation number %d symbol index idx=%d cannot be large then number of symbols %d", j, r.SymbolTableIndex, len(f.COFFSymbols)) 270 } 271 pesym := &f.COFFSymbols[r.SymbolTableIndex] 272 _, gosym, err := readpesym(l, arch, lookup, f, pesym, sectsyms, localSymVersion) 273 if err != nil { 274 return nil, nil, err 275 } 276 if gosym == 0 { 277 name, err := pesym.FullName(f.StringTable) 278 if err != nil { 279 name = string(pesym.Name[:]) 280 } 281 return nil, nil, fmt.Errorf("reloc of invalid sym %s idx=%d type=%d", name, r.SymbolTableIndex, pesym.Type) 282 } 283 284 rSym := gosym 285 rSize := uint8(4) 286 rOff := int32(r.VirtualAddress) 287 var rAdd int64 288 var rType objabi.RelocType 289 switch arch.Family { 290 default: 291 return nil, nil, fmt.Errorf("%s: unsupported arch %v", pn, arch.Family) 292 case sys.I386, sys.AMD64: 293 switch r.Type { 294 default: 295 return nil, nil, fmt.Errorf("%s: %v: unknown relocation type %v", pn, sectsyms[rsect], r.Type) 296 297 case IMAGE_REL_I386_REL32, IMAGE_REL_AMD64_REL32, 298 IMAGE_REL_AMD64_ADDR32, // R_X86_64_PC32 299 IMAGE_REL_AMD64_ADDR32NB: 300 rType = objabi.R_PCREL 301 302 rAdd = int64(int32(binary.LittleEndian.Uint32(sectdata[rsect][rOff:]))) 303 304 case IMAGE_REL_I386_DIR32NB, IMAGE_REL_I386_DIR32: 305 rType = objabi.R_ADDR 306 307 // load addend from image 308 rAdd = int64(int32(binary.LittleEndian.Uint32(sectdata[rsect][rOff:]))) 309 310 case IMAGE_REL_AMD64_ADDR64: // R_X86_64_64 311 rSize = 8 312 313 rType = objabi.R_ADDR 314 315 // load addend from image 316 rAdd = int64(binary.LittleEndian.Uint64(sectdata[rsect][rOff:])) 317 } 318 319 case sys.ARM: 320 switch r.Type { 321 default: 322 return nil, nil, fmt.Errorf("%s: %v: unknown ARM relocation type %v", pn, sectsyms[rsect], r.Type) 323 324 case IMAGE_REL_ARM_SECREL: 325 rType = objabi.R_PCREL 326 327 rAdd = int64(int32(binary.LittleEndian.Uint32(sectdata[rsect][rOff:]))) 328 329 case IMAGE_REL_ARM_ADDR32, IMAGE_REL_ARM_ADDR32NB: 330 rType = objabi.R_ADDR 331 332 rAdd = int64(int32(binary.LittleEndian.Uint32(sectdata[rsect][rOff:]))) 333 334 case IMAGE_REL_ARM_BRANCH24: 335 rType = objabi.R_CALLARM 336 337 rAdd = int64(int32(binary.LittleEndian.Uint32(sectdata[rsect][rOff:]))) 338 } 339 340 case sys.ARM64: 341 switch r.Type { 342 default: 343 return nil, nil, fmt.Errorf("%s: %v: unknown ARM64 relocation type %v", pn, sectsyms[rsect], r.Type) 344 345 case IMAGE_REL_ARM64_ADDR32, IMAGE_REL_ARM64_ADDR32NB: 346 rType = objabi.R_ADDR 347 348 rAdd = int64(int32(binary.LittleEndian.Uint32(sectdata[rsect][rOff:]))) 349 } 350 } 351 352 // ld -r could generate multiple section symbols for the 353 // same section but with different values, we have to take 354 // that into account, or in the case of split resources, 355 // the section and its symbols are split into two sections. 356 if issect(pesym) || splitResources { 357 rAdd += int64(pesym.Value) 358 } 359 360 rel, _ := sb.AddRel(rType) 361 rel.SetOff(rOff) 362 rel.SetSiz(rSize) 363 rel.SetSym(rSym) 364 rel.SetAdd(rAdd) 365 } 366 367 sb.SortRelocs() 368 } 369 370 // enter sub-symbols into symbol table. 371 for i, numaux := 0, 0; i < len(f.COFFSymbols); i += numaux + 1 { 372 pesym := &f.COFFSymbols[i] 373 374 numaux = int(pesym.NumberOfAuxSymbols) 375 376 name, err := pesym.FullName(f.StringTable) 377 if err != nil { 378 return nil, nil, err 379 } 380 if name == "" { 381 continue 382 } 383 if issect(pesym) { 384 continue 385 } 386 if int(pesym.SectionNumber) > len(f.Sections) { 387 continue 388 } 389 if pesym.SectionNumber == IMAGE_SYM_DEBUG { 390 continue 391 } 392 if pesym.SectionNumber == IMAGE_SYM_ABSOLUTE && bytes.Equal(pesym.Name[:], []byte("@feat.00")) { 393 // Microsoft's linker looks at whether all input objects have an empty 394 // section called @feat.00. If all of them do, then it enables SEH; 395 // otherwise it doesn't enable that feature. So, since around the Windows 396 // XP SP2 era, most tools that make PE objects just tack on that section, 397 // so that it won't gimp Microsoft's linker logic. Go doesn't support SEH, 398 // so in theory, none of this really matters to us. But actually, if the 399 // linker tries to ingest an object with @feat.00 -- which are produced by 400 // LLVM's resource compiler, for example -- it chokes because of the 401 // IMAGE_SYM_ABSOLUTE section that it doesn't know how to deal with. Since 402 // @feat.00 is just a marking anyway, skip IMAGE_SYM_ABSOLUTE sections that 403 // are called @feat.00. 404 continue 405 } 406 var sect *pe.Section 407 if pesym.SectionNumber > 0 { 408 sect = f.Sections[pesym.SectionNumber-1] 409 if _, found := sectsyms[sect]; !found { 410 continue 411 } 412 } 413 414 bld, s, err := readpesym(l, arch, lookup, f, pesym, sectsyms, localSymVersion) 415 if err != nil { 416 return nil, nil, err 417 } 418 419 if pesym.SectionNumber == 0 { // extern 420 if l.SymType(s) == sym.SDYNIMPORT { 421 bld = makeUpdater(l, bld, s) 422 bld.SetPlt(-2) // flag for dynimport in PE object files. 423 } 424 if l.SymType(s) == sym.SXREF && pesym.Value > 0 { // global data 425 bld = makeUpdater(l, bld, s) 426 bld.SetType(sym.SNOPTRDATA) 427 bld.SetSize(int64(pesym.Value)) 428 } 429 430 continue 431 } else if pesym.SectionNumber > 0 && int(pesym.SectionNumber) <= len(f.Sections) { 432 sect = f.Sections[pesym.SectionNumber-1] 433 if _, found := sectsyms[sect]; !found { 434 return nil, nil, fmt.Errorf("%s: %v: missing sect.sym", pn, s) 435 } 436 } else { 437 return nil, nil, fmt.Errorf("%s: %v: sectnum < 0!", pn, s) 438 } 439 440 if sect == nil { 441 return nil, nil, nil 442 } 443 444 if l.OuterSym(s) != 0 { 445 if l.AttrDuplicateOK(s) { 446 continue 447 } 448 outerName := l.SymName(l.OuterSym(s)) 449 sectName := l.SymName(sectsyms[sect]) 450 return nil, nil, fmt.Errorf("%s: duplicate symbol reference: %s in both %s and %s", pn, l.SymName(s), outerName, sectName) 451 } 452 453 bld = makeUpdater(l, bld, s) 454 sectsym := sectsyms[sect] 455 bld.SetType(l.SymType(sectsym)) 456 l.AddInteriorSym(sectsym, s) 457 bld.SetValue(int64(pesym.Value)) 458 bld.SetSize(4) 459 if l.SymType(sectsym) == sym.STEXT { 460 if bld.External() && !bld.DuplicateOK() { 461 return nil, nil, fmt.Errorf("%s: duplicate symbol definition", l.SymName(s)) 462 } 463 bld.SetExternal(true) 464 } 465 } 466 467 // Sort outer lists by address, adding to textp. 468 // This keeps textp in increasing address order. 469 for _, sect := range f.Sections { 470 s := sectsyms[sect] 471 if s == 0 { 472 continue 473 } 474 l.SortSub(s) 475 if l.SymType(s) == sym.STEXT { 476 for ; s != 0; s = l.SubSym(s) { 477 if l.AttrOnList(s) { 478 return nil, nil, fmt.Errorf("symbol %s listed multiple times", l.SymName(s)) 479 } 480 l.SetAttrOnList(s, true) 481 textp = append(textp, s) 482 } 483 } 484 } 485 486 return textp, rsrc, nil 487} 488 489func issect(s *pe.COFFSymbol) bool { 490 return s.StorageClass == IMAGE_SYM_CLASS_STATIC && s.Type == 0 && s.Name[0] == '.' 491} 492 493func readpesym(l *loader.Loader, arch *sys.Arch, lookup func(string, int) loader.Sym, f *pe.File, pesym *pe.COFFSymbol, sectsyms map[*pe.Section]loader.Sym, localSymVersion int) (*loader.SymbolBuilder, loader.Sym, error) { 494 symname, err := pesym.FullName(f.StringTable) 495 if err != nil { 496 return nil, 0, err 497 } 498 var name string 499 if issect(pesym) { 500 name = l.SymName(sectsyms[f.Sections[pesym.SectionNumber-1]]) 501 } else { 502 name = symname 503 switch arch.Family { 504 case sys.AMD64: 505 if name == "__imp___acrt_iob_func" { 506 // Do not rename __imp___acrt_iob_func into __acrt_iob_func, 507 // because __imp___acrt_iob_func symbol is real 508 // (see commit b295099 from git://git.code.sf.net/p/mingw-w64/mingw-w64 for details). 509 } else { 510 name = strings.TrimPrefix(name, "__imp_") // __imp_Name => Name 511 } 512 case sys.I386: 513 if name == "__imp____acrt_iob_func" { 514 // Do not rename __imp____acrt_iob_func into ___acrt_iob_func, 515 // because __imp____acrt_iob_func symbol is real 516 // (see commit b295099 from git://git.code.sf.net/p/mingw-w64/mingw-w64 for details). 517 } else { 518 name = strings.TrimPrefix(name, "__imp_") // __imp_Name => Name 519 } 520 if name[0] == '_' { 521 name = name[1:] // _Name => Name 522 } 523 } 524 } 525 526 // remove last @XXX 527 if i := strings.LastIndex(name, "@"); i >= 0 { 528 name = name[:i] 529 } 530 531 var s loader.Sym 532 var bld *loader.SymbolBuilder 533 switch pesym.Type { 534 default: 535 return nil, 0, fmt.Errorf("%s: invalid symbol type %d", symname, pesym.Type) 536 537 case IMAGE_SYM_DTYPE_FUNCTION, IMAGE_SYM_DTYPE_NULL: 538 switch pesym.StorageClass { 539 case IMAGE_SYM_CLASS_EXTERNAL: //global 540 s = lookup(name, 0) 541 542 case IMAGE_SYM_CLASS_NULL, IMAGE_SYM_CLASS_STATIC, IMAGE_SYM_CLASS_LABEL: 543 s = lookup(name, localSymVersion) 544 bld = makeUpdater(l, bld, s) 545 bld.SetDuplicateOK(true) 546 547 default: 548 return nil, 0, fmt.Errorf("%s: invalid symbol binding %d", symname, pesym.StorageClass) 549 } 550 } 551 552 if s != 0 && l.SymType(s) == 0 && (pesym.StorageClass != IMAGE_SYM_CLASS_STATIC || pesym.Value != 0) { 553 bld = makeUpdater(l, bld, s) 554 bld.SetType(sym.SXREF) 555 } 556 if strings.HasPrefix(symname, "__imp_") { 557 bld = makeUpdater(l, bld, s) 558 bld.SetGot(-2) // flag for __imp_ 559 } 560 561 return bld, s, nil 562} 563