src/cmd/ld/ldpe.c - go - Git at Google

 // Copyright 2010 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.

 #include	"l.h"
 #include	"lib.h"
 #include	"../ld/pe.h"

 #define IMAGE_SCN_MEM_DISCARDABLE 0x2000000

 #define IMAGE_SYM_UNDEFINED	0
 #define IMAGE_SYM_ABSOLUTE (-1)
 #define IMAGE_SYM_DEBUG	(-2)
 #define IMAGE_SYM_TYPE_NULL 0
 #define IMAGE_SYM_TYPE_VOID 1
 #define IMAGE_SYM_TYPE_CHAR 2
 #define IMAGE_SYM_TYPE_SHORT 3
 #define IMAGE_SYM_TYPE_INT 4
 #define IMAGE_SYM_TYPE_LONG 5
 #define IMAGE_SYM_TYPE_FLOAT 6
 #define IMAGE_SYM_TYPE_DOUBLE 7
 #define IMAGE_SYM_TYPE_STRUCT 8
 #define IMAGE_SYM_TYPE_UNION 9
 #define IMAGE_SYM_TYPE_ENUM 10
 #define IMAGE_SYM_TYPE_MOE 11
 #define IMAGE_SYM_TYPE_BYTE 12
 #define IMAGE_SYM_TYPE_WORD 13
 #define IMAGE_SYM_TYPE_UINT 14
 #define IMAGE_SYM_TYPE_DWORD 15
 #define IMAGE_SYM_TYPE_PCODE 32768
 #define IMAGE_SYM_DTYPE_NULL 0
 #define IMAGE_SYM_DTYPE_POINTER 0x10
 #define IMAGE_SYM_DTYPE_FUNCTION 0x20
 #define IMAGE_SYM_DTYPE_ARRAY 0x30
 #define IMAGE_SYM_CLASS_END_OF_FUNCTION	(-1)
 #define IMAGE_SYM_CLASS_NULL 0
 #define IMAGE_SYM_CLASS_AUTOMATIC 1
 #define IMAGE_SYM_CLASS_EXTERNAL 2
 #define IMAGE_SYM_CLASS_STATIC 3
 #define IMAGE_SYM_CLASS_REGISTER 4
 #define IMAGE_SYM_CLASS_EXTERNAL_DEF 5
 #define IMAGE_SYM_CLASS_LABEL 6
 #define IMAGE_SYM_CLASS_UNDEFINED_LABEL 7
 #define IMAGE_SYM_CLASS_MEMBER_OF_STRUCT 8
 #define IMAGE_SYM_CLASS_ARGUMENT 9
 #define IMAGE_SYM_CLASS_STRUCT_TAG 10
 #define IMAGE_SYM_CLASS_MEMBER_OF_UNION 11
 #define IMAGE_SYM_CLASS_UNION_TAG 12
 #define IMAGE_SYM_CLASS_TYPE_DEFINITION 13
 #define IMAGE_SYM_CLASS_UNDEFINED_STATIC 14
 #define IMAGE_SYM_CLASS_ENUM_TAG 15
 #define IMAGE_SYM_CLASS_MEMBER_OF_ENUM 16
 #define IMAGE_SYM_CLASS_REGISTER_PARAM 17
 #define IMAGE_SYM_CLASS_BIT_FIELD 18
 #define IMAGE_SYM_CLASS_FAR_EXTERNAL 68 /* Not in PECOFF v8 spec */
 #define IMAGE_SYM_CLASS_BLOCK 100
 #define IMAGE_SYM_CLASS_FUNCTION 101
 #define IMAGE_SYM_CLASS_END_OF_STRUCT 102
 #define IMAGE_SYM_CLASS_FILE 103
 #define IMAGE_SYM_CLASS_SECTION 104
 #define IMAGE_SYM_CLASS_WEAK_EXTERNAL 105
 #define IMAGE_SYM_CLASS_CLR_TOKEN 107

 #define IMAGE_REL_I386_ABSOLUTE	0x0000
 #define IMAGE_REL_I386_DIR16	0x0001
 #define IMAGE_REL_I386_REL16	0x0002
 #define IMAGE_REL_I386_DIR32	0x0006
 #define IMAGE_REL_I386_DIR32NB	0x0007
 #define IMAGE_REL_I386_SEG12	0x0009
 #define IMAGE_REL_I386_SECTION	0x000A
 #define IMAGE_REL_I386_SECREL	0x000B
 #define IMAGE_REL_I386_TOKEN	0x000C
 #define IMAGE_REL_I386_SECREL7	0x000D
 #define IMAGE_REL_I386_REL32	0x0014

 #define IMAGE_REL_AMD64_ABSOLUTE 0x0000
 #define IMAGE_REL_AMD64_ADDR64 0x0001 // R_X86_64_64
 #define IMAGE_REL_AMD64_ADDR32 0x0002 // R_X86_64_PC32
 #define IMAGE_REL_AMD64_ADDR32NB 0x0003
 #define IMAGE_REL_AMD64_REL32 0x0004
 #define IMAGE_REL_AMD64_REL32_1 0x0005
 #define IMAGE_REL_AMD64_REL32_2 0x0006
 #define IMAGE_REL_AMD64_REL32_3 0x0007
 #define IMAGE_REL_AMD64_REL32_4 0x0008
 #define IMAGE_REL_AMD64_REL32_5 0x0009
 #define IMAGE_REL_AMD64_SECTION 0x000A
 #define IMAGE_REL_AMD64_SECREL 0x000B
 #define IMAGE_REL_AMD64_SECREL7 0x000C
 #define IMAGE_REL_AMD64_TOKEN 0x000D
 #define IMAGE_REL_AMD64_SREL32 0x000E
 #define IMAGE_REL_AMD64_PAIR 0x000F
 #define IMAGE_REL_AMD64_SSPAN32 0x0010

 typedef struct PeSym PeSym;
 typedef struct PeSect PeSect;
 typedef struct PeObj PeObj;

 struct PeSym {
 	char* name;
 	uint32 value;
 	uint16 sectnum;
 	uint16 type;
 	uint8 sclass;
 	uint8 aux;
 	Sym* sym;
 };

 struct PeSect {
 	char* name;
 	uchar* base;
 	uint64 size;
 	Sym* sym;
 	IMAGE_SECTION_HEADER sh;
 };

 struct PeObj {
 	Biobuf	*f;
 	char	*name;
 	uint32 base;

 	PeSect	*sect;
 	uint	nsect;
 	PeSym	*pesym;
 	uint npesym;

 	IMAGE_FILE_HEADER fh;
 	char* snames;
 };

 static int map(PeObj *obj, PeSect *sect);
 static int readsym(PeObj *obj, int i, PeSym **sym);

 void
 ldpe(Biobuf *f, char *pkg, int64 len, char *pn)
 {
 	char *name;
 	int32 base;
 	int i, j, l, numaux;
 	PeObj *obj;
 	PeSect *sect, *rsect;
 	IMAGE_SECTION_HEADER sh;
 	uchar symbuf[18];
 	Sym *s;
 	Reloc *r, *rp;
 	PeSym *sym;

 	USED(len);
 	USED(pkg);
 	if(debug['v'])
 		Bprint(&bso, "%5.2f ldpe %s\n", cputime(), pn);

 	sect = nil;
 	version++;
 	base = Boffset(f);

 	obj = mal(sizeof *obj);
 	obj->f = f;
 	obj->base = base;
 	obj->name = pn;
 	// read header
 	if(Bread(f, &obj->fh, sizeof obj->fh) != sizeof obj->fh)
 		goto bad;
 	// load section list
 	obj->sect = mal(obj->fh.NumberOfSections*sizeof obj->sect[0]);
 	obj->nsect = obj->fh.NumberOfSections;
 	for(i=0; i < obj->fh.NumberOfSections; i++) {
 		if(Bread(f, &obj->sect[i].sh, sizeof sh) != sizeof sh)
 			goto bad;
 		obj->sect[i].size = obj->sect[i].sh.SizeOfRawData;
 		obj->sect[i].name = (char*)obj->sect[i].sh.Name;
 		// TODO return error if found .cormeta
 	}
 	// load string table
 	Bseek(f, base+obj->fh.PointerToSymbolTable+18*obj->fh.NumberOfSymbols, 0);
 	if(Bread(f, &l, sizeof l) != sizeof l)
 		goto bad;
 	obj->snames = mal(l);
 	Bseek(f, base+obj->fh.PointerToSymbolTable+18*obj->fh.NumberOfSymbols, 0);
 	if(Bread(f, obj->snames, l) != l)
 		goto bad;
 	// read symbols
 	obj->pesym = mal(obj->fh.NumberOfSymbols*sizeof obj->pesym[0]);
 	obj->npesym = obj->fh.NumberOfSymbols;
 	Bseek(f, base+obj->fh.PointerToSymbolTable, 0);
 	for(i=0; i<obj->fh.NumberOfSymbols; i+=numaux+1) {
 		Bseek(f, base+obj->fh.PointerToSymbolTable+sizeof(symbuf)*i, 0);
 		if(Bread(f, symbuf, sizeof symbuf) != sizeof symbuf)
 			goto bad;

 		if((symbuf[0] == 0) && (symbuf[1] == 0) &&
 			 (symbuf[2] == 0) && (symbuf[3] == 0)) {
 			l = le32(&symbuf[4]);
 			obj->pesym[i].name = (char*)&obj->snames[l];
 		} else { // sym name length <= 8
 			obj->pesym[i].name = mal(9);
 			strncpy(obj->pesym[i].name, (char*)symbuf, 8);
 			obj->pesym[i].name[8] = 0;
 		}
 		obj->pesym[i].value = le32(&symbuf[8]);
 		obj->pesym[i].sectnum = le16(&symbuf[12]);
 		obj->pesym[i].sclass = symbuf[16];
 		obj->pesym[i].aux = symbuf[17];
 		obj->pesym[i].type = le16(&symbuf[14]);
 		numaux = obj->pesym[i].aux;
 		if (numaux < 0)
 			numaux = 0;
 	}
 	// create symbols for mapped sections
 	for(i=0; i<obj->nsect; i++) {
 		sect = &obj->sect[i];
 		if(sect->sh.Characteristics&IMAGE_SCN_MEM_DISCARDABLE)
 			continue;
 		if(map(obj, sect) < 0)
 			goto bad;

 		name = smprint("%s(%s)", pn, sect->name);
 		s = lookup(name, version);
 		free(name);
 		switch(sect->sh.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)) {
 			case IMAGE_SCN_CNT_INITIALIZED_DATA|IMAGE_SCN_MEM_READ: //.rdata
 				s->type = SRODATA;
 				break;
 			case IMAGE_SCN_CNT_UNINITIALIZED_DATA|IMAGE_SCN_MEM_READ|IMAGE_SCN_MEM_WRITE: //.bss
 				s->type = SBSS;
 				break;
 			case IMAGE_SCN_CNT_INITIALIZED_DATA|IMAGE_SCN_MEM_READ|IMAGE_SCN_MEM_WRITE: //.data
 				s->type = SDATA;
 				break;
 			case IMAGE_SCN_CNT_CODE|IMAGE_SCN_MEM_EXECUTE|IMAGE_SCN_MEM_READ: //.text
 				s->type = STEXT;
 				break;
 			default:
 				werrstr("unexpected flags for PE section %s", sect->name);
 				goto bad;
 		}
 		s->p = sect->base;
 		s->np = sect->size;
 		s->size = sect->size;
 		if(s->type == STEXT) {
 			if(etextp)
 				etextp->next = s;
 			else
 				textp = s;
 			etextp = s;
 		}
 		sect->sym = s;
 		if(strcmp(sect->name, ".rsrc") == 0)
 			setpersrc(sect->sym);
 	}

 	// load relocations
 	for(i=0; i<obj->nsect; i++) {
 		rsect = &obj->sect[i];
 		if(rsect->sym == 0 || rsect->sh.NumberOfRelocations == 0)
 			continue;
 		if(rsect->sh.Characteristics&IMAGE_SCN_MEM_DISCARDABLE)
 			continue;
 		r = mal(rsect->sh.NumberOfRelocations*sizeof r[0]);
 		Bseek(f, obj->base+rsect->sh.PointerToRelocations, 0);
 		for(j=0; j<rsect->sh.NumberOfRelocations; j++) {
 			rp = &r[j];
 			if(Bread(f, symbuf, 10) != 10)
 				goto bad;

 			uint32 rva, symindex;
 			uint16 type;
 			rva = le32(&symbuf[0]);
 			symindex = le32(&symbuf[4]);
 			type = le16(&symbuf[8]);
 			if(readsym(obj, symindex, &sym) < 0)
 				goto bad;
 			if(sym->sym == nil) {
 				werrstr("reloc of invalid sym %s idx=%d type=%d", sym->name, symindex, sym->type);
 				goto bad;
 			}
 			rp->sym = sym->sym;
 			rp->siz = 4;
 			rp->off = rva;
 			switch(type) {
 				default:
 					diag("%s: unknown relocation type %d;", pn, type);
 				case IMAGE_REL_I386_REL32:
 				case IMAGE_REL_AMD64_REL32:
 					rp->type = D_PCREL;
 					rp->add = le32(rsect->base+rp->off);
 					break;
 				case IMAGE_REL_I386_DIR32NB:
 				case IMAGE_REL_I386_DIR32:
 					rp->type = D_ADDR;
 					// load addend from image
 					rp->add = le32(rsect->base+rp->off);
 					break;
 				case IMAGE_REL_AMD64_ADDR32: // R_X86_64_PC32
 					rp->type = D_PCREL;
 					rp->add += 4;
 					break;
 				case IMAGE_REL_AMD64_ADDR64: // R_X86_64_64
 					rp->siz = 8;
 					rp->type = D_ADDR;
 					// load addend from image
 					rp->add = le64(rsect->base+rp->off);
 					break;
 			}
 		}
 		qsort(r, rsect->sh.NumberOfRelocations, sizeof r[0], rbyoff);

 		s = rsect->sym;
 		s->r = r;
 		s->nr = rsect->sh.NumberOfRelocations;
 	}

 	// enter sub-symbols into symbol table.
 	for(i=0; i<obj->npesym; i++) {
 		if(obj->pesym[i].name == 0)
 			continue;
 		if(obj->pesym[i].name[0] == '.') //skip section
 			continue;
 		if(obj->pesym[i].sectnum > 0) {
 			sect = &obj->sect[obj->pesym[i].sectnum-1];
 			if(sect->sym == 0)
 				continue;
 		}
 		if(readsym(obj, i, &sym) < 0)
 			goto bad;

 		s = sym->sym;
 		if(sym->sectnum == 0) {// extern
 			if(s->type == SDYNIMPORT)
 				s->plt = -2; // flag for dynimport in PE object files.
 			if (s->type == SXREF && sym->value > 0) {// global data
 				s->type = SDATA;
 				s->size = sym->value;
 			}
 			continue;
 		} else if (sym->sectnum > 0) {
 			sect = &obj->sect[sym->sectnum-1];
 			if(sect->sym == 0)
 				diag("%s: %s sym == 0!", pn, s->name);
 		} else {
 			diag("%s: %s sectnum < 0!", pn, s->name);
 		}

 		if(sect == nil)
 			return;
 		s->sub = sect->sym->sub;
 		sect->sym->sub = s;
 		s->type = sect->sym->type | SSUB;
 		s->value = sym->value;
 		s->size = 4;
 		s->outer = sect->sym;
 		if(sect->sym->type == STEXT) {
 			Prog *p;

 			if(s->text != P)
 				diag("%s: duplicate definition of %s", pn, s->name);
 			// build a TEXT instruction with a unique pc
 			// just to make the rest of the linker happy.
 			p = prg();
 			p->as = ATEXT;
 			p->from.type = D_EXTERN;
 			p->from.sym = s;
 			p->textflag = 7;
 			p->to.type = D_CONST;
 			p->link = nil;
 			p->pc = pc++;
 			s->text = p;

 			etextp->next = s;
 			etextp = s;
 		}
 	}

 	return;
 bad:
 	diag("%s: malformed pe file: %r", pn);
 }

 static int
 map(PeObj *obj, PeSect *sect)
 {
 	if(sect->base != nil)
 		return 0;

 	sect->base = mal(sect->sh.SizeOfRawData);
 	if(sect->sh.PointerToRawData == 0) // .bss doesn't have data in object file
 		return 0;
 	werrstr("short read");
 	if(Bseek(obj->f, obj->base+sect->sh.PointerToRawData, 0) < 0 ||
 			Bread(obj->f, sect->base, sect->sh.SizeOfRawData) != sect->sh.SizeOfRawData)
 		return -1;

 	return 0;
 }

 static int
 readsym(PeObj *obj, int i, PeSym **y)
 {
 	Sym *s;
 	PeSym *sym;
 	char *name, *p;

 	if(i >= obj->npesym || i < 0) {
 		werrstr("invalid pe symbol index");
 		return -1;
 	}

 	sym = &obj->pesym[i];
 	*y = sym;

 	if(sym->name[0] == '.') // .section
 		name = obj->sect[sym->sectnum-1].sym->name;
 	else {
 		name = sym->name;
 		if(strncmp(name, "__imp_", 6) == 0)
 			name = &name[6]; // __imp_Name => Name
 		if(thechar == '8' && name[0] == '_')
 			name = &name[1]; // _Name => Name
 	}
 	// remove last @XXX
 	p = strchr(name, '@');
 	if(p)
 		*p = 0;

 	switch(sym->type) {
 	default:
 		werrstr("%s: invalid symbol type %d", sym->name, sym->type);
 		return -1;
 	case IMAGE_SYM_DTYPE_FUNCTION:
 	case IMAGE_SYM_DTYPE_NULL:
 		switch(sym->sclass) {
 		case IMAGE_SYM_CLASS_EXTERNAL: //global
 			s = lookup(name, 0);
 			break;
 		case IMAGE_SYM_CLASS_NULL:
 		case IMAGE_SYM_CLASS_STATIC:
 			s = lookup(name, version);
 			break;
 		default:
 			werrstr("%s: invalid symbol binding %d", sym->name, sym->sclass);
 			return -1;
 		}
 		break;
 	}

 	if(s != nil && s->type == 0 && !(sym->sclass == IMAGE_SYM_CLASS_STATIC && sym->value == 0))
 		s->type = SXREF;
 	if(strncmp(sym->name, "__imp_", 6) == 0)
 		s->got = -2; // flag for __imp_
 	sym->sym = s;

 	return 0;
 }
	// Copyright 2010 The Go Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style
	// license that can be found in the LICENSE file.

	#include "l.h"
	#include "lib.h"
	#include "../ld/pe.h"

	#define IMAGE_SCN_MEM_DISCARDABLE 0x2000000

	#define IMAGE_SYM_UNDEFINED 0
	#define IMAGE_SYM_ABSOLUTE (-1)
	#define IMAGE_SYM_DEBUG (-2)
	#define IMAGE_SYM_TYPE_NULL 0
	#define IMAGE_SYM_TYPE_VOID 1
	#define IMAGE_SYM_TYPE_CHAR 2
	#define IMAGE_SYM_TYPE_SHORT 3
	#define IMAGE_SYM_TYPE_INT 4
	#define IMAGE_SYM_TYPE_LONG 5
	#define IMAGE_SYM_TYPE_FLOAT 6
	#define IMAGE_SYM_TYPE_DOUBLE 7
	#define IMAGE_SYM_TYPE_STRUCT 8
	#define IMAGE_SYM_TYPE_UNION 9
	#define IMAGE_SYM_TYPE_ENUM 10
	#define IMAGE_SYM_TYPE_MOE 11
	#define IMAGE_SYM_TYPE_BYTE 12
	#define IMAGE_SYM_TYPE_WORD 13
	#define IMAGE_SYM_TYPE_UINT 14
	#define IMAGE_SYM_TYPE_DWORD 15
	#define IMAGE_SYM_TYPE_PCODE 32768
	#define IMAGE_SYM_DTYPE_NULL 0
	#define IMAGE_SYM_DTYPE_POINTER 0x10
	#define IMAGE_SYM_DTYPE_FUNCTION 0x20
	#define IMAGE_SYM_DTYPE_ARRAY 0x30
	#define IMAGE_SYM_CLASS_END_OF_FUNCTION (-1)
	#define IMAGE_SYM_CLASS_NULL 0
	#define IMAGE_SYM_CLASS_AUTOMATIC 1
	#define IMAGE_SYM_CLASS_EXTERNAL 2
	#define IMAGE_SYM_CLASS_STATIC 3
	#define IMAGE_SYM_CLASS_REGISTER 4
	#define IMAGE_SYM_CLASS_EXTERNAL_DEF 5
	#define IMAGE_SYM_CLASS_LABEL 6
	#define IMAGE_SYM_CLASS_UNDEFINED_LABEL 7
	#define IMAGE_SYM_CLASS_MEMBER_OF_STRUCT 8
	#define IMAGE_SYM_CLASS_ARGUMENT 9
	#define IMAGE_SYM_CLASS_STRUCT_TAG 10
	#define IMAGE_SYM_CLASS_MEMBER_OF_UNION 11
	#define IMAGE_SYM_CLASS_UNION_TAG 12
	#define IMAGE_SYM_CLASS_TYPE_DEFINITION 13
	#define IMAGE_SYM_CLASS_UNDEFINED_STATIC 14
	#define IMAGE_SYM_CLASS_ENUM_TAG 15
	#define IMAGE_SYM_CLASS_MEMBER_OF_ENUM 16
	#define IMAGE_SYM_CLASS_REGISTER_PARAM 17
	#define IMAGE_SYM_CLASS_BIT_FIELD 18
	#define IMAGE_SYM_CLASS_FAR_EXTERNAL 68 /* Not in PECOFF v8 spec */
	#define IMAGE_SYM_CLASS_BLOCK 100
	#define IMAGE_SYM_CLASS_FUNCTION 101
	#define IMAGE_SYM_CLASS_END_OF_STRUCT 102
	#define IMAGE_SYM_CLASS_FILE 103
	#define IMAGE_SYM_CLASS_SECTION 104
	#define IMAGE_SYM_CLASS_WEAK_EXTERNAL 105
	#define IMAGE_SYM_CLASS_CLR_TOKEN 107

	#define IMAGE_REL_I386_ABSOLUTE 0x0000
	#define IMAGE_REL_I386_DIR16 0x0001
	#define IMAGE_REL_I386_REL16 0x0002
	#define IMAGE_REL_I386_DIR32 0x0006
	#define IMAGE_REL_I386_DIR32NB 0x0007
	#define IMAGE_REL_I386_SEG12 0x0009
	#define IMAGE_REL_I386_SECTION 0x000A
	#define IMAGE_REL_I386_SECREL 0x000B
	#define IMAGE_REL_I386_TOKEN 0x000C
	#define IMAGE_REL_I386_SECREL7 0x000D
	#define IMAGE_REL_I386_REL32 0x0014

	#define IMAGE_REL_AMD64_ABSOLUTE 0x0000
	#define IMAGE_REL_AMD64_ADDR64 0x0001 // R_X86_64_64
	#define IMAGE_REL_AMD64_ADDR32 0x0002 // R_X86_64_PC32
	#define IMAGE_REL_AMD64_ADDR32NB 0x0003
	#define IMAGE_REL_AMD64_REL32 0x0004
	#define IMAGE_REL_AMD64_REL32_1 0x0005
	#define IMAGE_REL_AMD64_REL32_2 0x0006
	#define IMAGE_REL_AMD64_REL32_3 0x0007
	#define IMAGE_REL_AMD64_REL32_4 0x0008
	#define IMAGE_REL_AMD64_REL32_5 0x0009
	#define IMAGE_REL_AMD64_SECTION 0x000A
	#define IMAGE_REL_AMD64_SECREL 0x000B
	#define IMAGE_REL_AMD64_SECREL7 0x000C
	#define IMAGE_REL_AMD64_TOKEN 0x000D
	#define IMAGE_REL_AMD64_SREL32 0x000E
	#define IMAGE_REL_AMD64_PAIR 0x000F
	#define IMAGE_REL_AMD64_SSPAN32 0x0010

	typedef struct PeSym PeSym;
	typedef struct PeSect PeSect;
	typedef struct PeObj PeObj;

	struct PeSym {
	char* name;
	uint32 value;
	uint16 sectnum;
	uint16 type;
	uint8 sclass;
	uint8 aux;
	Sym* sym;
	};

	struct PeSect {
	char* name;
	uchar* base;
	uint64 size;
	Sym* sym;
	IMAGE_SECTION_HEADER sh;
	};

	struct PeObj {
	Biobuf *f;
	char *name;
	uint32 base;

	PeSect *sect;
	uint nsect;
	PeSym *pesym;
	uint npesym;

	IMAGE_FILE_HEADER fh;
	char* snames;
	};

	static int map(PeObj obj, PeSect sect);
	static int readsym(PeObj obj, int i, PeSym *sym);

	void
	ldpe(Biobuf f, char pkg, int64 len, char *pn)
	{
	char *name;
	int32 base;
	int i, j, l, numaux;
	PeObj *obj;
	PeSect sect, rsect;
	IMAGE_SECTION_HEADER sh;
	uchar symbuf[18];
	Sym *s;
	Reloc r, rp;
	PeSym *sym;

	USED(len);
	USED(pkg);
	if(debug['v'])
	Bprint(&bso, "%5.2f ldpe %s\n", cputime(), pn);

	sect = nil;
	version++;
	base = Boffset(f);

	obj = mal(sizeof *obj);
	obj->f = f;
	obj->base = base;
	obj->name = pn;
	// read header
	if(Bread(f, &obj->fh, sizeof obj->fh) != sizeof obj->fh)
	goto bad;
	// load section list
	obj->sect = mal(obj->fh.NumberOfSections*sizeof obj->sect[0]);
	obj->nsect = obj->fh.NumberOfSections;
	for(i=0; i < obj->fh.NumberOfSections; i++) {
	if(Bread(f, &obj->sect[i].sh, sizeof sh) != sizeof sh)
	goto bad;
	obj->sect[i].size = obj->sect[i].sh.SizeOfRawData;
	obj->sect[i].name = (char*)obj->sect[i].sh.Name;
	// TODO return error if found .cormeta
	}
	// load string table
	Bseek(f, base+obj->fh.PointerToSymbolTable+18*obj->fh.NumberOfSymbols, 0);
	if(Bread(f, &l, sizeof l) != sizeof l)
	goto bad;
	obj->snames = mal(l);
	Bseek(f, base+obj->fh.PointerToSymbolTable+18*obj->fh.NumberOfSymbols, 0);
	if(Bread(f, obj->snames, l) != l)
	goto bad;
	// read symbols
	obj->pesym = mal(obj->fh.NumberOfSymbols*sizeof obj->pesym[0]);
	obj->npesym = obj->fh.NumberOfSymbols;
	Bseek(f, base+obj->fh.PointerToSymbolTable, 0);
	for(i=0; i<obj->fh.NumberOfSymbols; i+=numaux+1) {
	Bseek(f, base+obj->fh.PointerToSymbolTable+sizeof(symbuf)*i, 0);
	if(Bread(f, symbuf, sizeof symbuf) != sizeof symbuf)
	goto bad;

	if((symbuf[0] == 0) && (symbuf[1] == 0) &&
	(symbuf[2] == 0) && (symbuf[3] == 0)) {
	l = le32(&symbuf[4]);
	obj->pesym[i].name = (char*)&obj->snames[l];
	} else { // sym name length <= 8
	obj->pesym[i].name = mal(9);
	strncpy(obj->pesym[i].name, (char*)symbuf, 8);
	obj->pesym[i].name[8] = 0;
	}
	obj->pesym[i].value = le32(&symbuf[8]);
	obj->pesym[i].sectnum = le16(&symbuf[12]);
	obj->pesym[i].sclass = symbuf[16];
	obj->pesym[i].aux = symbuf[17];
	obj->pesym[i].type = le16(&symbuf[14]);
	numaux = obj->pesym[i].aux;
	if (numaux < 0)
	numaux = 0;
	}
	// create symbols for mapped sections
	for(i=0; i<obj->nsect; i++) {
	sect = &obj->sect[i];
	if(sect->sh.Characteristics&IMAGE_SCN_MEM_DISCARDABLE)
	continue;
	if(map(obj, sect) < 0)
	goto bad;

	name = smprint("%s(%s)", pn, sect->name);
	s = lookup(name, version);
	free(name);
	switch(sect->sh.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)) {
	case IMAGE_SCN_CNT_INITIALIZED_DATA\|IMAGE_SCN_MEM_READ: //.rdata
	s->type = SRODATA;
	break;
	case IMAGE_SCN_CNT_UNINITIALIZED_DATA\|IMAGE_SCN_MEM_READ\|IMAGE_SCN_MEM_WRITE: //.bss
	s->type = SBSS;
	break;
	case IMAGE_SCN_CNT_INITIALIZED_DATA\|IMAGE_SCN_MEM_READ\|IMAGE_SCN_MEM_WRITE: //.data
	s->type = SDATA;
	break;
	case IMAGE_SCN_CNT_CODE\|IMAGE_SCN_MEM_EXECUTE\|IMAGE_SCN_MEM_READ: //.text
	s->type = STEXT;
	break;
	default:
	werrstr("unexpected flags for PE section %s", sect->name);
	goto bad;
	}
	s->p = sect->base;
	s->np = sect->size;
	s->size = sect->size;
	if(s->type == STEXT) {
	if(etextp)
	etextp->next = s;
	else
	textp = s;
	etextp = s;
	}
	sect->sym = s;
	if(strcmp(sect->name, ".rsrc") == 0)
	setpersrc(sect->sym);
	}

	// load relocations
	for(i=0; i<obj->nsect; i++) {
	rsect = &obj->sect[i];
	if(rsect->sym == 0 \|\| rsect->sh.NumberOfRelocations == 0)
	continue;
	if(rsect->sh.Characteristics&IMAGE_SCN_MEM_DISCARDABLE)
	continue;
	r = mal(rsect->sh.NumberOfRelocations*sizeof r[0]);
	Bseek(f, obj->base+rsect->sh.PointerToRelocations, 0);
	for(j=0; j<rsect->sh.NumberOfRelocations; j++) {
	rp = &r[j];
	if(Bread(f, symbuf, 10) != 10)
	goto bad;

	uint32 rva, symindex;
	uint16 type;
	rva = le32(&symbuf[0]);
	symindex = le32(&symbuf[4]);
	type = le16(&symbuf[8]);
	if(readsym(obj, symindex, &sym) < 0)
	goto bad;
	if(sym->sym == nil) {
	werrstr("reloc of invalid sym %s idx=%d type=%d", sym->name, symindex, sym->type);
	goto bad;
	}
	rp->sym = sym->sym;
	rp->siz = 4;
	rp->off = rva;
	switch(type) {
	default:
	diag("%s: unknown relocation type %d;", pn, type);
	case IMAGE_REL_I386_REL32:
	case IMAGE_REL_AMD64_REL32:
	rp->type = D_PCREL;
	rp->add = le32(rsect->base+rp->off);
	break;
	case IMAGE_REL_I386_DIR32NB:
	case IMAGE_REL_I386_DIR32:
	rp->type = D_ADDR;
	// load addend from image
	rp->add = le32(rsect->base+rp->off);
	break;
	case IMAGE_REL_AMD64_ADDR32: // R_X86_64_PC32
	rp->type = D_PCREL;
	rp->add += 4;
	break;
	case IMAGE_REL_AMD64_ADDR64: // R_X86_64_64
	rp->siz = 8;
	rp->type = D_ADDR;
	// load addend from image
	rp->add = le64(rsect->base+rp->off);
	break;
	}
	}
	qsort(r, rsect->sh.NumberOfRelocations, sizeof r[0], rbyoff);

	s = rsect->sym;
	s->r = r;
	s->nr = rsect->sh.NumberOfRelocations;
	}

	// enter sub-symbols into symbol table.
	for(i=0; i<obj->npesym; i++) {
	if(obj->pesym[i].name == 0)
	continue;
	if(obj->pesym[i].name[0] == '.') //skip section
	continue;
	if(obj->pesym[i].sectnum > 0) {
	sect = &obj->sect[obj->pesym[i].sectnum-1];
	if(sect->sym == 0)
	continue;
	}
	if(readsym(obj, i, &sym) < 0)
	goto bad;

	s = sym->sym;
	if(sym->sectnum == 0) {// extern
	if(s->type == SDYNIMPORT)
	s->plt = -2; // flag for dynimport in PE object files.
	if (s->type == SXREF && sym->value > 0) {// global data
	s->type = SDATA;
	s->size = sym->value;
	}
	continue;
	} else if (sym->sectnum > 0) {
	sect = &obj->sect[sym->sectnum-1];
	if(sect->sym == 0)
	diag("%s: %s sym == 0!", pn, s->name);
	} else {
	diag("%s: %s sectnum < 0!", pn, s->name);
	}

	if(sect == nil)
	return;
	s->sub = sect->sym->sub;
	sect->sym->sub = s;
	s->type = sect->sym->type \| SSUB;
	s->value = sym->value;
	s->size = 4;
	s->outer = sect->sym;
	if(sect->sym->type == STEXT) {
	Prog *p;

	if(s->text != P)
	diag("%s: duplicate definition of %s", pn, s->name);
	// build a TEXT instruction with a unique pc
	// just to make the rest of the linker happy.
	p = prg();
	p->as = ATEXT;
	p->from.type = D_EXTERN;
	p->from.sym = s;
	p->textflag = 7;
	p->to.type = D_CONST;
	p->link = nil;
	p->pc = pc++;
	s->text = p;

	etextp->next = s;
	etextp = s;
	}
	}

	return;
	bad:
	diag("%s: malformed pe file: %r", pn);
	}

	static int
	map(PeObj obj, PeSect sect)
	{
	if(sect->base != nil)
	return 0;

	sect->base = mal(sect->sh.SizeOfRawData);
	if(sect->sh.PointerToRawData == 0) // .bss doesn't have data in object file
	return 0;
	werrstr("short read");
	if(Bseek(obj->f, obj->base+sect->sh.PointerToRawData, 0) < 0 \|\|
	Bread(obj->f, sect->base, sect->sh.SizeOfRawData) != sect->sh.SizeOfRawData)
	return -1;

	return 0;
	}

	static int
	readsym(PeObj obj, int i, PeSym *y)
	{
	Sym *s;
	PeSym *sym;
	char name, p;

	if(i >= obj->npesym \|\| i < 0) {
	werrstr("invalid pe symbol index");
	return -1;
	}

	sym = &obj->pesym[i];
	*y = sym;

	if(sym->name[0] == '.') // .section
	name = obj->sect[sym->sectnum-1].sym->name;
	else {
	name = sym->name;
	if(strncmp(name, "__imp_", 6) == 0)
	name = &name[6]; // __imp_Name => Name
	if(thechar == '8' && name[0] == '_')
	name = &name[1]; // _Name => Name
	}
	// remove last @XXX
	p = strchr(name, '@');
	if(p)
	*p = 0;

	switch(sym->type) {
	default:
	werrstr("%s: invalid symbol type %d", sym->name, sym->type);
	return -1;
	case IMAGE_SYM_DTYPE_FUNCTION:
	case IMAGE_SYM_DTYPE_NULL:
	switch(sym->sclass) {
	case IMAGE_SYM_CLASS_EXTERNAL: //global
	s = lookup(name, 0);
	break;
	case IMAGE_SYM_CLASS_NULL:
	case IMAGE_SYM_CLASS_STATIC:
	s = lookup(name, version);
	break;
	default:
	werrstr("%s: invalid symbol binding %d", sym->name, sym->sclass);
	return -1;
	}
	break;
	}

	if(s != nil && s->type == 0 && !(sym->sclass == IMAGE_SYM_CLASS_STATIC && sym->value == 0))
	s->type = SXREF;
	if(strncmp(sym->name, "__imp_", 6) == 0)
	s->got = -2; // flag for __imp_
	sym->sym = s;

	return 0;
	}