cgo: windows/386 port

R=rsc, peterGo, brainman
CC=golang-dev
http://codereview.appspot.com/3733046

Committer: Russ Cox <rsc@golang.org>

17 files changed, 559 insertions, 14 deletions

diff --git a/src/cmd/5l/Makefile b/src/cmd/5l/Makefile
index 71798724b..c11ebe990 100644
--- a/src/cmd/5l/Makefile
+++ b/src/cmd/5l/Makefile
@@ -14,6 +14,7 @@ OFILES=\
 	enam.$O\
 	ldelf.$O\
 	ldmacho.$O\
+	ldpe.$O\
 	lib.$O\
 	list.$O\
 	noop.$O\
diff --git a/src/cmd/6l/Makefile b/src/cmd/6l/Makefile
index f7d2a550c..abe204d4f 100644
--- a/src/cmd/6l/Makefile
+++ b/src/cmd/6l/Makefile
@@ -16,6 +16,7 @@ OFILES=\
 	go.$O\
 	ldelf.$O\
 	ldmacho.$O\
+	ldpe.$O\
 	lib.$O\
 	list.$O\
 	macho.$O\
diff --git a/src/cmd/8l/Makefile b/src/cmd/8l/Makefile
index 84976ba18..a85e3ffa7 100644
--- a/src/cmd/8l/Makefile
+++ b/src/cmd/8l/Makefile
@@ -16,6 +16,7 @@ OFILES=\
 	go.$O\
 	ldelf.$O\
 	ldmacho.$O\
+	ldpe.$O\
 	lib.$O\
 	list.$O\
 	macho.$O\
diff --git a/src/cmd/cgo/main.go b/src/cmd/cgo/main.go
index 942bda5f4..14bb7ec2b 100644
--- a/src/cmd/cgo/main.go
+++ b/src/cmd/cgo/main.go
@@ -20,6 +20,7 @@ import (
 	"os"
 	"reflect"
 	"strings"
+	"runtime"
 )
 
 // A Package collects information about the package we're going to write.
@@ -127,6 +128,13 @@ func main() {
 		// specialized knowledge gcc has about where to look for imported
 		// symbols and which ones to use.
 		syms, imports := dynimport(*dynobj)
+		if runtime.GOOS == "windows" {
+			for _, sym := range syms {
+				ss := strings.Split(sym, ":", -1)
+				fmt.Printf("#pragma dynimport %s %s %q\n", ss[0], ss[0], strings.ToLower(ss[1]))
+			}
+			return
+		}
 		for _, sym := range syms {
 			fmt.Printf("#pragma dynimport %s %s %q\n", sym, sym, "")
 		}
diff --git a/src/cmd/cgo/out.go b/src/cmd/cgo/out.go
index c76616677..d5fc63409 100644
--- a/src/cmd/cgo/out.go
+++ b/src/cmd/cgo/out.go
@@ -8,6 +8,7 @@ import (
 	"bytes"
 	"debug/elf"
 	"debug/macho"
+	"debug/pe"
 	"fmt"
 	"go/ast"
 	"go/printer"
@@ -103,12 +104,14 @@ func dynimport(obj string) (syms, imports []string) {
 		ImportedSymbols() ([]string, os.Error)
 	}
 	var isMacho bool
-	var err1, err2 os.Error
+	var err1, err2, err3 os.Error
 	if f, err1 = elf.Open(obj); err1 != nil {
-		if f, err2 = macho.Open(obj); err2 != nil {
-			fatal("cannot parse %s as ELF (%v) or Mach-O (%v)", obj, err1, err2)
+		if f, err2 = pe.Open(obj); err2 != nil {
+			if f, err3 = macho.Open(obj); err3 != nil {
+				fatal("cannot parse %s as ELF (%v) or PE (%v) or Mach-O (%v)", obj, err1, err2, err3)
+			}
+			isMacho = true
 		}
-		isMacho = true
 	}
 
 	var err os.Error
diff --git a/src/cmd/gopack/ar.c b/src/cmd/gopack/ar.c
index 063967bd7..a16e98cfe 100644
--- a/src/cmd/gopack/ar.c
+++ b/src/cmd/gopack/ar.c
@@ -607,6 +607,7 @@ scanobj(Biobuf *b, Arfile *ap, long size)
 		
 		/* maybe a foreign object file?  that's okay */
 		if((buf[0] == 0x7F && buf[1] == 'E' && buf[2] == 'L' && buf[3] == 'F') ||   // ELF
+		   (buf[0] == 0x4c && buf[1] == 0x01 || buf[0] == 0x64 && buf[1] == 0x86) || // Windows PE
 		   (buf[0] == 0xFE && buf[1] == 0xED && buf[2] == 0xFA && (buf[3]&~1) == 0xCE) ||  // Mach-O big-endian
 		   (buf[3] == 0xFE && buf[2] == 0xED && buf[1] == 0xFA && (buf[0]&~1) == 0xCE)) {  // Mach-O little-endian
 			Bseek(b, offset, 0);
diff --git a/src/cmd/ld/data.c b/src/cmd/ld/data.c
index 27e0078d7..0551232cf 100644
--- a/src/cmd/ld/data.c
+++ b/src/cmd/ld/data.c
@@ -240,6 +240,33 @@ void
 dynrelocsym(Sym *s)
 {
 	Reloc *r;
+	
+	if(thechar == '8' && HEADTYPE == 10) { // Windows PE
+		Sym *rel, *targ;
+		
+		rel = lookup(".rel", 0);
+		if(s == rel)
+			return;
+		for(r=s->r; r<s->r+s->nr; r++) {
+			targ = r->sym;
+			if(r->sym->plt == -2) { // make dynimport JMP table for PE object files.
+				targ->plt = rel->size;
+				r->sym = rel;
+				r->add = targ->plt;
+				
+				// jmp *addr
+				adduint8(rel, 0xff);
+				adduint8(rel, 0x25);
+				addaddr(rel, targ);
+				adduint8(rel, 0x90);
+				adduint8(rel, 0x90);
+			} else if(r->sym->plt >= 0) {
+				r->sym = rel;
+				r->add = targ->plt;
+			}
+		}
+		return;
+	}
 
 	for(r=s->r; r<s->r+s->nr; r++)
 		if(r->sym->type == SDYNIMPORT || r->type >= 256)
diff --git a/src/cmd/ld/ldpe.c b/src/cmd/ld/ldpe.c
new file mode 100644
index 000000000..66b122bb3
--- /dev/null
+++ b/src/cmd/ld/ldpe.c
@@ -0,0 +1,404 @@
+// 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
+
+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;
+	
+	if(debug['v'])
+		Bprint(&bso, "%5.2f ldpe %s\n", cputime(), pn);
+	
+	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 .rsrc
+	}
+	// 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 {
+			obj->pesym[i].name = strdup((char*)symbuf);
+		}
+		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
+			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;
+	}
+	
+	// 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:
+					rp->type = D_PCREL;
+					rp->add = 0;
+					break;
+				case IMAGE_REL_I386_DIR32:
+					rp->type = D_ADDR;
+					// load addend from image
+					rp->add = le32(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.
+	// frist 2 entry is file name.
+	for(i=2; 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.
+			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, sym->sectnum);
+		}
+
+		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);
+	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;
+	s = nil;
+	
+	name = sym->name;
+	if(sym->sclass == IMAGE_SYM_CLASS_STATIC && sym->value == 0) // section
+		name = obj->sect[sym->sectnum-1].sym->name;
+	if(strncmp(sym->name, "__imp__", 6) == 0)
+		name = &sym->name[7]; // __imp__Name => Name
+	else if(sym->name[0] == '_') 
+		name = &sym->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;
+	sym->sym = s;
+
+	return 0;
+}
diff --git a/src/cmd/ld/lib.c b/src/cmd/ld/lib.c
index ae77247c3..b1a62f25e 100644
--- a/src/cmd/ld/lib.c
+++ b/src/cmd/ld/lib.c
@@ -406,6 +406,10 @@ ldobj(Biobuf *f, char *pkg, int64 len, char *pn, int whence)
 		ldmacho(f, pkg, len, pn);
 		return;
 	}
+	if(c1 == 0x4c && c2 == 0x01 || c1 == 0x64 && c2 == 0x86) {
+		ldpe(f, pkg, len, pn);
+		return;
+	}
 
 	/* check the header */
 	line = Brdline(f, '\n');
diff --git a/src/cmd/ld/pe.c b/src/cmd/ld/pe.c
index b8ce99e3e..7ce6767a2 100644
--- a/src/cmd/ld/pe.c
+++ b/src/cmd/ld/pe.c
@@ -297,6 +297,13 @@ addimports(vlong fileoff, IMAGE_SECTION_HEADER *datsect)
 void
 dope(void)
 {
+	Sym *rel;
+
+	/* relocation table */
+	rel = lookup(".rel", 0);
+	rel->reachable = 1;
+	rel->type = SELFDATA;
+
 	initdynimport();
 }
 
diff --git a/src/pkg/Makefile b/src/pkg/Makefile
index b9031d359..3494e1c13 100644
--- a/src/pkg/Makefile
+++ b/src/pkg/Makefile
@@ -151,10 +151,6 @@ DIRS+=\
 
 endif
 
-ifeq ($(GOOS),windows)
-DIRS:=$(filter-out runtime/cgo,$(DIRS))
-endif
-
 NOTEST=\
 	debug/proc\
 	exp/draw/x11\
diff --git a/src/pkg/debug/pe/file.go b/src/pkg/debug/pe/file.go
index 904d2f863..82c02407b 100644
--- a/src/pkg/debug/pe/file.go
+++ b/src/pkg/debug/pe/file.go
@@ -49,6 +49,17 @@ type Section struct {
 	sr *io.SectionReader
 }
 
+type ImportDirectory struct {
+	OriginalFirstThunk uint32
+	TimeDateStamp      uint32
+	ForwarderChain     uint32
+	Name               uint32
+	FirstThunk         uint32
+
+	dll string
+	rva []uint32
+}
+
 // Data reads and returns the contents of the PE section.
 func (s *Section) Data() ([]byte, os.Error) {
 	dat := make([]byte, s.sr.Size())
@@ -229,3 +240,70 @@ func (f *File) DWARF() (*dwarf.Data, os.Error) {
 	abbrev, info, str := dat[0], dat[1], dat[2]
 	return dwarf.New(abbrev, nil, nil, info, nil, nil, nil, str)
 }
+
+// ImportedSymbols returns the names of all symbols
+// referred to by the binary f that are expected to be
+// satisfied by other libraries at dynamic load time.
+// It does not return weak symbols.
+func (f *File) ImportedSymbols() ([]string, os.Error) {
+	ds := f.Section(".idata")
+	if ds == nil {
+		// not dynamic, so no libraries
+		return nil, nil
+	}
+	d, err := ds.Data()
+	if err != nil {
+		return nil, err
+	}
+	var ida []ImportDirectory
+	for len(d) > 0 {
+		var dt ImportDirectory
+		dt.OriginalFirstThunk = binary.LittleEndian.Uint32(d[0:4])
+		dt.Name = binary.LittleEndian.Uint32(d[12:16])
+		dt.FirstThunk = binary.LittleEndian.Uint32(d[16:20])
+		d = d[20:]
+		if dt.OriginalFirstThunk == 0 {
+			break
+		}
+		ida = append(ida, dt)
+	}
+	for i, _ := range ida {
+		for len(d) > 0 {
+			va := binary.LittleEndian.Uint32(d[0:4])
+			d = d[4:]
+			if va == 0 {
+				break
+			}
+			ida[i].rva = append(ida[i].rva, va)
+		}
+	}
+	for _, _ = range ida {
+		for len(d) > 0 {
+			va := binary.LittleEndian.Uint32(d[0:4])
+			d = d[4:]
+			if va == 0 {
+				break
+			}
+		}
+	}
+	names, _ := ds.Data()
+	var all []string
+	for _, dt := range ida {
+		dt.dll, _ = getString(names, int(dt.Name-ds.VirtualAddress))
+		for _, va := range dt.rva {
+			fn, _ := getString(names, int(va-ds.VirtualAddress+2))
+			all = append(all, fn+":"+dt.dll)
+		}
+	}
+
+	return all, nil
+}
+
+// ImportedLibraries returns the names of all libraries
+// referred to by the binary f that are expected to be
+// linked with the binary at dynamic link time.
+func (f *File) ImportedLibraries() ([]string, os.Error) {
+	// TODO
+	// cgo -dynimport don't use this for windows PE, so just return.
+	return nil, nil
+}
diff --git a/src/pkg/runtime/386/asm.s b/src/pkg/runtime/386/asm.s
index 101a0cf52..58ca712ef 100644
--- a/src/pkg/runtime/386/asm.s
+++ b/src/pkg/runtime/386/asm.s
@@ -18,9 +18,10 @@ TEXT _rt0_386(SB),7,$0
 	// we set up GS ourselves.
 	MOVL	initcgo(SB), AX
 	TESTL	AX, AX
-	JZ	3(PC)
+	JZ	4(PC)
 	CALL	AX
-	JMP	ok
+	CMPL runtime·iswindows(SB), $0
+	JEQ ok
 
 	// set up %gs
 	CALL	runtime·ldt0setup(SB)
diff --git a/src/pkg/runtime/cgo/Makefile b/src/pkg/runtime/cgo/Makefile
index dc9ffb411..a2ce902d6 100644
--- a/src/pkg/runtime/cgo/Makefile
+++ b/src/pkg/runtime/cgo/Makefile
@@ -30,7 +30,11 @@ OFILES=\
 	_cgo_import.$O\
 	$(CGO_OFILES)\
 
+ifeq ($(GOOS),windows)
+CGO_LDFLAGS=-lm -mthreads
+else
 CGO_LDFLAGS=-lpthread
+endif
 
 ifeq ($(GOOS),freebsd)
 OFILES+=\
diff --git a/src/pkg/runtime/cgo/windows_386.c b/src/pkg/runtime/cgo/windows_386.c
index 5f5235bd2..f39309cb1 100755
--- a/src/pkg/runtime/cgo/windows_386.c
+++ b/src/pkg/runtime/cgo/windows_386.c
@@ -30,6 +30,7 @@ static void*
 threadentry(void *v)
 {
 	ThreadStart ts;
+	void *tls0;
 
 	ts = *(ThreadStart*)v;
 	free(v);
@@ -45,13 +46,17 @@ threadentry(void *v)
 	/*
 	 * Set specific keys in thread local storage.
 	 */
+	tls0 = (void*)LocalAlloc(LPTR, 32);
 	asm volatile (
-		"MOVL %%fs:0x2c, %%eax\n"	// MOVL 0x24(FS), tmp
-		"movl %0, 0(%%eax)\n"	// MOVL g, 0(FS)
-		"movl %1, 4(%%eax)\n"	// MOVL m, 4(FS)
-		:: "r"(ts.g), "r"(ts.m) : "%eax"
+		"movl %0, %%fs:0x2c\n"	// MOVL tls0, 0x2c(FS)
+		"movl %%fs:0x2c, %%eax\n"	// MOVL 0x2c(FS), tmp
+		"movl %1, 0(%%eax)\n"	// MOVL g, 0(FS)
+		"movl %2, 4(%%eax)\n"	// MOVL m, 4(FS)
+		:: "r"(tls0), "r"(ts.g), "r"(ts.m) : "%eax"
 	);
 	
 	crosscall_386(ts.fn);
+	
+	LocalFree(tls0);
 	return nil;
 }
diff --git a/src/pkg/runtime/runtime.c b/src/pkg/runtime/runtime.c
index 513675240..8d3675070 100644
--- a/src/pkg/runtime/runtime.c
+++ b/src/pkg/runtime/runtime.c
@@ -153,6 +153,7 @@ runtime·args(int32 c, uint8 **v)
 }
 
 int32 runtime·isplan9;
+int32 runtime·iswindows;
 
 void
 runtime·goargs(void)
diff --git a/src/pkg/runtime/windows/386/rt0.s b/src/pkg/runtime/windows/386/rt0.s
index 4b67a9f42..3b023de2f 100644
--- a/src/pkg/runtime/windows/386/rt0.s
+++ b/src/pkg/runtime/windows/386/rt0.s
@@ -9,3 +9,6 @@ TEXT _rt0_386_windows(SB),7,$0
 	MOVL	SP, 0(FS)
 
 	JMP	_rt0_386(SB)
+
+DATA  runtime·iswindows(SB)/4, $1
+GLOBL runtime·iswindows(SB), $4