ld: add .gcdata and .gcbss sections

R=rsc
CC=golang-dev
https://golang.org/cl/6281048

src/cmd/5l/asm.c

@@ -505,6 +505,8 @@ doelf(void)
 	if(HEADTYPE == Hnetbsd)
 		elfstr[ElfStrNoteNetbsdIdent] = addstring(shstrtab, ".note.netbsd.ident");
 	addstring(shstrtab, ".rodata");
+	addstring(shstrtab, ".gcdata");
+	addstring(shstrtab, ".gcbss");
 	addstring(shstrtab, ".gosymtab");
 	addstring(shstrtab, ".gopclntab");
 	if(!debug['s']) {
@@ -661,7 +663,7 @@ asmb(void)
 	cseek(sect->vaddr - segtext.vaddr + segtext.fileoff);
 	codeblk(sect->vaddr, sect->len);
 
-	/* output read-only data in text segment (rodata, gosymtab and pclntab) */
+	/* output read-only data in text segment (rodata, gosymtab, pclntab, ...) */
 	for(sect = sect->next; sect != nil; sect = sect->next) {
 		cseek(sect->vaddr - segtext.vaddr + segtext.fileoff);
 		datblk(sect->vaddr, sect->len);
@@ -2274,6 +2276,8 @@ genasmsym(void (*put)(Sym*, char*, int, vlong, vlong, int, Sym*))
 			case SNOPTRDATA:
 			case SSYMTAB:
 			case SPCLNTAB:
+			case SGCDATA:
+			case SGCBSS:
 				if(!s->reachable)
 					continue;
 				put(s, s->name, 'D', s->value, s->size, s->version, s->gotype);

src/cmd/6l/asm.c

@@ -579,6 +579,8 @@ doelf(void)
 		elfstr[ElfStrNoteNetbsdIdent] = addstring(shstrtab, ".note.netbsd.ident");
 	addstring(shstrtab, ".elfdata");
 	addstring(shstrtab, ".rodata");
+	addstring(shstrtab, ".gcdata");
+	addstring(shstrtab, ".gcbss");
 	addstring(shstrtab, ".gosymtab");
 	addstring(shstrtab, ".gopclntab");
 	if(!debug['s']) {
@@ -732,7 +734,7 @@ asmb(void)
 	cseek(sect->vaddr - segtext.vaddr + segtext.fileoff);
 	codeblk(sect->vaddr, sect->len);
 
-	/* output read-only data in text segment (rodata, gosymtab and pclntab) */
+	/* output read-only data in text segment (rodata, gosymtab, pclntab, ...) */
 	for(sect = sect->next; sect != nil; sect = sect->next) {
 		cseek(sect->vaddr - segtext.vaddr + segtext.fileoff);
 		datblk(sect->vaddr, sect->len);
@@ -1200,6 +1202,8 @@ genasmsym(void (*put)(Sym*, char*, int, vlong, vlong, int, Sym*))
 		case SSTRING:
 		case SGOSTRING:
 		case SWINDOWS:
+		case SGCDATA:
+		case SGCBSS:
 			if(!s->reachable)
 				continue;
 			put(s, s->name, 'D', symaddr(s), s->size, s->version, s->gotype);

src/cmd/8l/asm.c

@@ -536,6 +536,8 @@ doelf(void)
 		elfstr[ElfStrNoteNetbsdIdent] = addstring(shstrtab, ".note.netbsd.ident");
 	addstring(shstrtab, ".elfdata");
 	addstring(shstrtab, ".rodata");
+	addstring(shstrtab, ".gcdata");
+	addstring(shstrtab, ".gcbss");
 	addstring(shstrtab, ".gosymtab");
 	addstring(shstrtab, ".gopclntab");
 	if(!debug['s']) {
@@ -684,7 +686,7 @@ asmb(void)
 	cseek(sect->vaddr - segtext.vaddr + segtext.fileoff);
 	codeblk(sect->vaddr, sect->len);
 
-	/* output read-only data in text segment (rodata, gosymtab and pclntab) */
+	/* output read-only data in text segment (rodata, gosymtab, pclntab, ...) */
 	for(sect = sect->next; sect != nil; sect = sect->next) {
 		cseek(sect->vaddr - segtext.vaddr + segtext.fileoff);
 		datblk(sect->vaddr, sect->len);
@@ -1266,6 +1268,8 @@ genasmsym(void (*put)(Sym*, char*, int, vlong, vlong, int, Sym*))
 			case SNOPTRDATA:
 			case SSYMTAB:
 			case SPCLNTAB:
+			case SGCDATA:
+			case SGCBSS:
 				if(!s->reachable)
 					continue;
 				put(s, s->name, 'D', symaddr(s), s->size, s->version, s->gotype);

src/cmd/gc/subr.c

@@ -3515,7 +3515,6 @@ ngotype(Node *n)
 {
 	if(n->sym != S && n->realtype != T)
 	if(strncmp(n->sym->name, "autotmp_", 8) != 0)
-	if(strncmp(n->sym->name, "statictmp_", 8) != 0)
 		return typename(n->realtype)->left->sym;
 
 	return S;

src/cmd/ld/data.c

@@ -34,6 +34,7 @@
 #include	"../ld/lib.h"
 #include	"../ld/elf.h"
 #include	"../ld/pe.h"
+#include	"../../pkg/runtime/mgc0.h"
 
 void	dynreloc(void);
 static vlong addaddrplus4(Sym *s, Sym *t, int32 add);
@@ -628,41 +629,51 @@ addstring(Sym *s, char *str)
 }
 
 vlong
-adduintxx(Sym *s, uint64 v, int wid)
+setuintxx(Sym *s, vlong off, uint64 v, int wid)
 {
-	int32 i, r, fl;
+	int32 i, fl;
 	vlong o;
 	uchar *cast;
 
 	if(s->type == 0)
 		s->type = SDATA;
 	s->reachable = 1;
-	r = s->size;
+	if(s->size < off+wid) {
-	s->size += wid;
+		s->size = off+wid;
-	symgrow(s, s->size);
+		symgrow(s, s->size);
-	assert(r+wid <= s->size);
+	}
 	fl = v;
 	cast = (uchar*)&fl;
 	switch(wid) {
 	case 1:
-		s->p[r] = cast[inuxi1[0]];
+		s->p[off] = cast[inuxi1[0]];
 		break;
 	case 2:
 		for(i=0; i<2; i++)
-			s->p[r+i] = cast[inuxi2[i]];
+			s->p[off+i] = cast[inuxi2[i]];
 		break;
 	case 4:
 		for(i=0; i<4; i++)
-			s->p[r+i] = cast[inuxi4[i]];
+			s->p[off+i] = cast[inuxi4[i]];
 		break;
 	case 8:
 		o = v;
 		cast = (uchar*)&o;
 		for(i=0; i<8; i++)
-			s->p[r+i] = cast[inuxi8[i]];
+			s->p[off+i] = cast[inuxi8[i]];
 		break;
 	}
-	return r;
+	return off;
+}
+
+vlong
+adduintxx(Sym *s, uint64 v, int wid)
+{
+	int32 off;
+
+	off = s->size;
+	setuintxx(s, off, v, wid);
+	return off;
 }
 
 vlong
@@ -689,6 +700,30 @@ adduint64(Sym *s, uint64 v)
 	return adduintxx(s, v, 8);
 }
 
+void
+setuint8(Sym *s, vlong r, uint8 v)
+{
+	setuintxx(s, r, v, 1);
+}
+
+void
+setuint16(Sym *s, vlong r, uint16 v)
+{
+	setuintxx(s, r, v, 2);
+}
+
+void
+setuint32(Sym *s, vlong r, uint32 v)
+{
+	setuintxx(s, r, v, 4);
+}
+
+void
+setuint64(Sym *s, vlong r, uint64 v)
+{
+	setuintxx(s, r, v, 8);
+}
+
 vlong
 addaddrplus(Sym *s, Sym *t, int32 add)
 {
@@ -793,17 +828,87 @@ dosymtype(void)
 	}
 }
 
+static int32
+alignsymsize(int32 s)
+{
+	if(s >= PtrSize)
+		s = rnd(s, PtrSize);
+	else if(s > 2)
+		s = rnd(s, 4);
+	return s;
+}
+
+static int32
+aligndatsize(int32 datsize, Sym *s)
+{
+	int32 t;
+
+	if(s->align != 0) {
+		datsize = rnd(datsize, s->align);
+	} else {
+		t = alignsymsize(s->size);
+		if(t & 1) {
+			;
+		} else if(t & 2)
+			datsize = rnd(datsize, 2);
+		else if(t & 4)
+			datsize = rnd(datsize, 4);
+		else
+			datsize = rnd(datsize, 8);
+	}
+	return datsize;
+}
+
+static void
+gcaddsym(Sym *gc, Sym *s, int32 off)
+{
+	int32 a;
+	Sym *gotype;
+
+	if(s->size < PtrSize)
+		return;
+	if(strcmp(s->name, ".string") == 0)
+		return;
+
+	gotype = s->gotype;
+	if(gotype != nil) {
+		//print("gcaddsym:    %s    %d    %s\n", s->name, s->size, gotype->name);
+		adduintxx(gc, GC_CALL, PtrSize);
+		adduintxx(gc, off, PtrSize);
+		addaddrplus(gc, decodetype_gc(gotype), 1*PtrSize);
+	} else {
+		//print("gcaddsym:    %s    %d    <unknown type>\n", s->name, s->size);
+		for(a = -off&(PtrSize-1); a+PtrSize<=s->size; a+=PtrSize) {
+			adduintxx(gc, GC_APTR, PtrSize);
+			adduintxx(gc, off+a, PtrSize);
+		}
+	}
+}
+
 void
 dodata(void)
 {
 	int32 t, datsize;
-	Section *sect, *noptr;
+	Section *sect;
 	Sym *s, *last, **l;
+	Sym *gcdata1, *gcbss1;
 
 	if(debug['v'])
 		Bprint(&bso, "%5.2f dodata\n", cputime());
 	Bflush(&bso);
 
+	// define garbage collection symbols
+	gcdata1 = lookup("gcdata1", 0);
+	gcdata1->type = SGCDATA;
+	gcdata1->reachable = 1;
+	gcbss1 = lookup("gcbss1", 0);
+	gcbss1->type = SGCBSS;
+	gcbss1->reachable = 1;
+
+	// size of .data and .bss section. the zero value is later replaced by the actual size of the section.
+	adduintxx(gcdata1, 0, PtrSize);
+	adduintxx(gcbss1, 0, PtrSize);
+
 	last = nil;
 	datap = nil;
 
@@ -847,16 +952,102 @@ dodata(void)
 	datap = datsort(datap);
 
 	/*
-	 * allocate data sections.  list is sorted by type,
+	 * allocate sections.  list is sorted by type,
 	 * so we can just walk it for each piece we want to emit.
+	 * segdata is processed before segtext, because we need
+	 * to see all symbols in the .data and .bss sections in order
+	 * to generate garbage collection information.
 	 */
 
+	/* begin segdata */
+
+	/* skip symbols belonging to segtext */
+	s = datap;
+	for(; s != nil && s->type < SELFSECT; s = s->next);
+
+	/* writable ELF sections */
+	datsize = 0;
+	for(; s != nil && s->type < SNOPTRDATA; s = s->next) {
+		sect = addsection(&segdata, s->name, 06);
+		if(s->align != 0)
+			datsize = rnd(datsize, s->align);
+		sect->vaddr = datsize;
+		s->type = SDATA;
+		s->value = datsize;
+		datsize += rnd(s->size, PtrSize);
+		sect->len = datsize - sect->vaddr;
+	}
+
+	/* pointer-free data */
+	sect = addsection(&segdata, ".noptrdata", 06);
+	sect->vaddr = datsize;
+	for(; s != nil && s->type < SDATA; s = s->next) {
+		s->type = SDATA;
+		t = alignsymsize(s->size);
+		datsize = aligndatsize(datsize, s);
+		s->value = datsize;
+		datsize += t;
+	}
+	sect->len = datsize - sect->vaddr;
+	datsize = rnd(datsize, PtrSize);
+
+	/* data */
+	sect = addsection(&segdata, ".data", 06);
+	sect->vaddr = datsize;
+	for(; s != nil && s->type < SBSS; s = s->next) {
+		s->type = SDATA;
+		t = alignsymsize(s->size);
+		datsize = aligndatsize(datsize, s);
+		s->value = datsize;
+		gcaddsym(gcdata1, s, datsize - sect->vaddr);  // gc
+		datsize += t;
+	}
+	sect->len = datsize - sect->vaddr;
+	datsize = rnd(datsize, PtrSize);
+
+	adduintxx(gcdata1, GC_END, PtrSize);
+	setuintxx(gcdata1, 0, sect->len, PtrSize);
+
+	/* bss */
+	sect = addsection(&segdata, ".bss", 06);
+	sect->vaddr = datsize;
+	for(; s != nil && s->type < SNOPTRBSS; s = s->next) {
+		t = alignsymsize(s->size);
+		datsize = aligndatsize(datsize, s);
+		s->value = datsize;
+		gcaddsym(gcbss1, s, datsize - sect->vaddr);  // gc
+		datsize += t;
+	}
+	sect->len = datsize - sect->vaddr;
+	datsize = rnd(datsize, PtrSize);
+
+	adduintxx(gcbss1, GC_END, PtrSize);
+	setuintxx(gcbss1, 0, sect->len, PtrSize);
+
+	/* pointer-free bss */
+	sect = addsection(&segdata, ".noptrbss", 06);
+	sect->vaddr = datsize;
+	for(; s != nil; s = s->next) {
+		if(s->type > SNOPTRBSS) {
+			cursym = s;
+			diag("unexpected symbol type %d", s->type);
+		}
+		t = alignsymsize(s->size);
+		datsize = aligndatsize(datsize, s);
+		s->value = datsize;
+		datsize += t;
+	}
+	sect->len = datsize - sect->vaddr;
+	datsize = rnd(datsize, PtrSize);
+
+	/* we finished segdata, begin segtext */
+
 	/* read-only data */
 	sect = addsection(&segtext, ".rodata", 04);
 	sect->vaddr = 0;
 	datsize = 0;
 	s = datap;
-	for(; s != nil && s->type < SSYMTAB; s = s->next) {
+	for(; s != nil && s->type < SGCDATA; s = s->next) {
 		if(s->align != 0)
 			datsize = rnd(datsize, s->align);
 		s->type = SRODATA;
@@ -865,6 +1056,28 @@ dodata(void)
 	}
 	sect->len = datsize - sect->vaddr;
 
+	/* gcdata */
+	sect = addsection(&segtext, ".gcdata", 04);
+	sect->vaddr = datsize;
+	for(; s != nil && s->type == SGCDATA; s = s->next) {
+		s->type = SRODATA;
+		s->value = datsize;
+		datsize += s->size;
+	}
+	sect->len = datsize - sect->vaddr;
+	datsize = rnd(datsize, PtrSize);
+
+	/* gcbss */
+	sect = addsection(&segtext, ".gcbss", 04);
+	sect->vaddr = datsize;
+	for(; s != nil && s->type == SGCBSS; s = s->next) {
+		s->type = SRODATA;
+		s->value = datsize;
+		datsize += s->size;
+	}
+	sect->len = datsize - sect->vaddr;
+	datsize = rnd(datsize, PtrSize);
+
 	/* gosymtab */
 	sect = addsection(&segtext, ".gosymtab", 04);
 	sect->vaddr = datsize;
@@ -898,96 +1111,6 @@ dodata(void)
 		datsize += rnd(s->size, PtrSize);
 		sect->len = datsize - sect->vaddr;
 	}
-
-	/* writable ELF sections */
-	datsize = 0;
-	for(; s != nil && s->type < SNOPTRDATA; s = s->next) {
-		sect = addsection(&segdata, s->name, 06);
-		if(s->align != 0)
-			datsize = rnd(datsize, s->align);
-		sect->vaddr = datsize;
-		s->type = SDATA;
-		s->value = datsize;
-		datsize += rnd(s->size, PtrSize);
-		sect->len = datsize - sect->vaddr;
-	}
-	
-	/* pointer-free data, then data */
-	sect = addsection(&segdata, ".noptrdata", 06);
-	sect->vaddr = datsize;
-	noptr = sect;
-	for(; ; s = s->next) {
-		if((s == nil || s->type >= SDATA) && sect == noptr) {
-			// finish noptrdata, start data
-			datsize = rnd(datsize, 8);
-			sect->len = datsize - sect->vaddr;
-			sect = addsection(&segdata, ".data", 06);
-			sect->vaddr = datsize;
-		}
-		if(s == nil || s->type >= SBSS) {
-			// finish data
-			sect->len = datsize - sect->vaddr;
-			break;
-		}
-		s->type = SDATA;
-		t = s->size;
-		if(t >= PtrSize)
-			t = rnd(t, PtrSize);
-		else if(t > 2)
-			t = rnd(t, 4);
-		if(s->align != 0)
-			datsize = rnd(datsize, s->align);
-		else if(t & 1) {
-			;
-		} else if(t & 2)
-			datsize = rnd(datsize, 2);
-		else if(t & 4)
-			datsize = rnd(datsize, 4);
-		else
-			datsize = rnd(datsize, 8);
-		s->value = datsize;
-		datsize += t;
-	}
-
-	/* bss, then pointer-free bss */
-	noptr = nil;
-	sect = addsection(&segdata, ".bss", 06);
-	sect->vaddr = datsize;
-	for(; ; s = s->next) {
-		if((s == nil || s->type >= SNOPTRBSS) && noptr == nil) {
-			// finish bss, start noptrbss
-			datsize = rnd(datsize, 8);
-			sect->len = datsize - sect->vaddr;
-			sect = addsection(&segdata, ".noptrbss", 06);
-			sect->vaddr = datsize;
-			noptr = sect;
-		}
-		if(s == nil) {
-			sect->len = datsize - sect->vaddr;
-			break;
-		}
-		if(s->type > SNOPTRBSS) {
-			cursym = s;
-			diag("unexpected symbol type %d", s->type);
-		}
-		t = s->size;
-		if(t >= PtrSize)
-			t = rnd(t, PtrSize);
-		else if(t > 2)
-			t = rnd(t, 4);
-		if(s->align != 0)
-			datsize = rnd(datsize, s->align);
-		else if(t & 1) {
-			;
-		} else if(t & 2)
-			datsize = rnd(datsize, 2);
-		else if(t & 4)
-			datsize = rnd(datsize, 4);
-		else
-			datsize = rnd(datsize, 8);
-		s->value = datsize;
-		datsize += t;
-	}
 }
 
 // assign addresses to text
@@ -1038,6 +1161,7 @@ void
 address(void)
 {
 	Section *s, *text, *data, *rodata, *symtab, *pclntab, *noptr, *bss, *noptrbss;
+	Section *gcdata, *gcbss;
 	Sym *sym, *sub;
 	uvlong va;
 
@@ -1084,7 +1208,9 @@ address(void)
 
 	text = segtext.sect;
 	rodata = text->next;
-	symtab = rodata->next;
+	gcdata = rodata->next;
+	gcbss = gcdata->next;
+	symtab = gcbss->next;
 	pclntab = symtab->next;
 
 	for(sym = datap; sym != nil; sym = sym->next) {
@@ -1101,6 +1227,10 @@ address(void)
 	xdefine("etext", STEXT, text->vaddr + text->len);
 	xdefine("rodata", SRODATA, rodata->vaddr);
 	xdefine("erodata", SRODATA, rodata->vaddr + rodata->len);
+	xdefine("gcdata", SGCDATA, gcdata->vaddr);
+	xdefine("egcdata", SGCDATA, gcdata->vaddr + gcdata->len);
+	xdefine("gcbss", SGCBSS, gcbss->vaddr);
+	xdefine("egcbss", SGCBSS, gcbss->vaddr + gcbss->len);
 	xdefine("symtab", SRODATA, symtab->vaddr);
 	xdefine("esymtab", SRODATA, symtab->vaddr + symtab->len);
 	xdefine("pclntab", SRODATA, pclntab->vaddr);

src/cmd/ld/decodesym.c

@@ -0,0 +1,215 @@
+// Copyright 2012 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	"../../pkg/runtime/typekind.h"
+
+// Decoding the type.* symbols.	 This has to be in sync with
+// ../../pkg/runtime/type.go, or more specificaly, with what
+// ../gc/reflect.c stuffs in these.
+
+static Reloc*
+decode_reloc(Sym *s, int32 off)
+{
+	int i;
+
+	for (i = 0; i < s->nr; i++)
+		if (s->r[i].off == off)
+			return s->r + i;
+	return nil;
+}
+
+static Sym*
+decode_reloc_sym(Sym *s, int32 off)
+{
+	Reloc *r;
+
+	r = decode_reloc(s,off);
+	if (r == nil)
+		return nil;
+	return r->sym;
+}
+
+static uvlong
+decode_inuxi(uchar* p, int sz)
+{
+	uint64 v;
+	uint32 l;
+	uchar *cast, *inuxi;
+	int i;
+
+	v = l = 0;
+	cast = nil;
+	inuxi = nil;
+	switch (sz) {
+	case 2:
+		cast = (uchar*)&l;
+		inuxi = inuxi2;
+		break;
+	case 4:
+		cast = (uchar*)&l;
+		inuxi = inuxi4;
+		break;
+	case 8:
+		cast = (uchar*)&v;
+		inuxi = inuxi8;
+		break;
+	default:
+		diag("dwarf: decode inuxi %d", sz);
+		errorexit();
+	}
+	for (i = 0; i < sz; i++)
+		cast[inuxi[i]] = p[i];
+	if (sz == 8)
+		return v;
+	return l;
+}
+
+// Type.commonType.kind
+uint8
+decodetype_kind(Sym *s)
+{
+	return s->p[3*PtrSize + 7] & ~KindNoPointers;	//  0x13 / 0x1f
+}
+
+// Type.commonType.size
+vlong
+decodetype_size(Sym *s)
+{
+	return decode_inuxi(s->p + 2*PtrSize, PtrSize);	 // 0x8 / 0x10
+}
+
+// Type.commonType.gc
+Sym*
+decodetype_gc(Sym *s)
+{
+	return decode_reloc_sym(s, 3*PtrSize + 8 + 1*PtrSize);
+}
+
+// Type.ArrayType.elem and Type.SliceType.Elem
+Sym*
+decodetype_arrayelem(Sym *s)
+{
+	return decode_reloc_sym(s, CommonSize);	// 0x1c / 0x30
+}
+
+vlong
+decodetype_arraylen(Sym *s)
+{
+	return decode_inuxi(s->p + CommonSize+PtrSize, PtrSize);
+}
+
+// Type.PtrType.elem
+Sym*
+decodetype_ptrelem(Sym *s)
+{
+	return decode_reloc_sym(s, CommonSize);	// 0x1c / 0x30
+}
+
+// Type.MapType.key, elem
+Sym*
+decodetype_mapkey(Sym *s)
+{
+	return decode_reloc_sym(s, CommonSize);	// 0x1c / 0x30
+}
+Sym*
+decodetype_mapvalue(Sym *s)
+{
+	return decode_reloc_sym(s, CommonSize+PtrSize);	// 0x20 / 0x38
+}
+
+// Type.ChanType.elem
+Sym*
+decodetype_chanelem(Sym *s)
+{
+	return decode_reloc_sym(s, CommonSize);	// 0x1c / 0x30
+}
+
+// Type.FuncType.dotdotdot
+int
+decodetype_funcdotdotdot(Sym *s)
+{
+	return s->p[CommonSize];
+}
+
+// Type.FuncType.in.len
+int
+decodetype_funcincount(Sym *s)
+{
+	return decode_inuxi(s->p + CommonSize+2*PtrSize, 4);
+}
+
+int
+decodetype_funcoutcount(Sym *s)
+{
+	return decode_inuxi(s->p + CommonSize+3*PtrSize + 2*4, 4);
+}
+
+Sym*
+decodetype_funcintype(Sym *s, int i)
+{
+	Reloc *r;
+
+	r = decode_reloc(s, CommonSize + PtrSize);
+	if (r == nil)
+		return nil;
+	return decode_reloc_sym(r->sym, r->add + i * PtrSize);
+}
+
+Sym*
+decodetype_funcouttype(Sym *s, int i)
+{
+	Reloc *r;
+
+	r = decode_reloc(s, CommonSize + 2*PtrSize + 2*4);
+	if (r == nil)
+		return nil;
+	return decode_reloc_sym(r->sym, r->add + i * PtrSize);
+}
+
+// Type.StructType.fields.Slice::len
+int
+decodetype_structfieldcount(Sym *s)
+{
+	return decode_inuxi(s->p + CommonSize + PtrSize, 4);
+}
+
+enum {
+	StructFieldSize = 5*PtrSize
+};
+// Type.StructType.fields[]-> name, typ and offset.
+char*
+decodetype_structfieldname(Sym *s, int i)
+{
+	Reloc *r;
+
+	// go.string."foo"  0x28 / 0x40
+	s = decode_reloc_sym(s, CommonSize + PtrSize + 2*4 + i*StructFieldSize);
+	if (s == nil)			// embedded structs have a nil name.
+		return nil;
+	r = decode_reloc(s, 0);		// s has a pointer to the string data at offset 0
+	if (r == nil)			// shouldn't happen.
+		return nil;
+	return (char*) r->sym->p + r->add;	// the c-string
+}
+
+Sym*
+decodetype_structfieldtype(Sym *s, int i)
+{
+	return decode_reloc_sym(s, CommonSize + PtrSize + 2*4 + i*StructFieldSize + 2*PtrSize);
+}
+
+vlong
+decodetype_structfieldoffs(Sym *s, int i)
+{
+	return decode_inuxi(s->p + CommonSize + PtrSize + 2*4 + i*StructFieldSize + 4*PtrSize, 4);
+}
+
+// InterfaceTYpe.methods.len
+vlong
+decodetype_ifacemethodcount(Sym *s)
+{
+	return decode_inuxi(s->p + CommonSize + PtrSize, 4);
+}

src/cmd/ld/dwarf.c

@@ -19,6 +19,7 @@
 #include	"../ld/elf.h"
 #include	"../ld/macho.h"
 #include	"../ld/pe.h"
+#include	"../../pkg/runtime/typekind.h"
 
 /*
  * Offsets and sizes of the debug_* sections in the cout file.
@@ -740,241 +741,6 @@ newabslocexprattr(DWDie *die, vlong addr)
 	memmove(die->attr->data, block, i);
 }
 
-// Decoding the type.* symbols.	 This has to be in sync with
-// ../../pkg/runtime/type.go, or more specificaly, with what
-// ../gc/reflect.c stuffs in these.
-
-enum {
-	KindBool = 1,
-	KindInt,
-	KindInt8,
-	KindInt16,
-	KindInt32,
-	KindInt64,
-	KindUint,
-	KindUint8,
-	KindUint16,
-	KindUint32,
-	KindUint64,
-	KindUintptr,
-	KindFloat32,
-	KindFloat64,
-	KindComplex64,
-	KindComplex128,
-	KindArray,
-	KindChan,
-	KindFunc,
-	KindInterface,
-	KindMap,
-	KindPtr,
-	KindSlice,
-	KindString,
-	KindStruct,
-	KindUnsafePointer,
-
-	KindNoPointers = 1<<7,
-
-	// size of Type interface header + CommonType structure.
-	CommonSize = 2*PtrSize+ 6*PtrSize + 8,
-};
-
-static Reloc*
-decode_reloc(Sym *s, int32 off)
-{
-	int i;
-
-	for (i = 0; i < s->nr; i++)
-		if (s->r[i].off == off)
-			return s->r + i;
-	return nil;
-}
-
-static Sym*
-decode_reloc_sym(Sym *s, int32 off)
-{
-	Reloc *r;
-
-	r = decode_reloc(s,off);
-	if (r == nil)
-		return nil;
-	return r->sym;
-}
-
-static uvlong
-decode_inuxi(uchar* p, int sz)
-{
-	uint64 v;
-	uint32 l;
-	uchar *cast, *inuxi;
-	int i;
-
-	v = l = 0;
-	cast = nil;
-	inuxi = nil;
-	switch (sz) {
-	case 2:
-		cast = (uchar*)&l;
-		inuxi = inuxi2;
-		break;
-	case 4:
-		cast = (uchar*)&l;
-		inuxi = inuxi4;
-		break;
-	case 8:
-		cast = (uchar*)&v;
-		inuxi = inuxi8;
-		break;
-	default:
-		diag("dwarf: decode inuxi %d", sz);
-		errorexit();
-	}
-	for (i = 0; i < sz; i++)
-		cast[inuxi[i]] = p[i];
-	if (sz == 8)
-		return v;
-	return l;
-}
-
-// Type.commonType.kind
-static uint8
-decodetype_kind(Sym *s)
-{
-	return s->p[3*PtrSize + 7] & ~KindNoPointers;	//  0x13 / 0x1f
-}
-
-// Type.commonType.size
-static vlong
-decodetype_size(Sym *s)
-{
-	return decode_inuxi(s->p + 2*PtrSize, PtrSize);	 // 0x8 / 0x10
-}
-
-// Type.ArrayType.elem and Type.SliceType.Elem
-static Sym*
-decodetype_arrayelem(Sym *s)
-{
-	return decode_reloc_sym(s, CommonSize);	// 0x1c / 0x30
-}
-
-static vlong
-decodetype_arraylen(Sym *s)
-{
-	return decode_inuxi(s->p + CommonSize+PtrSize, PtrSize);
-}
-
-// Type.PtrType.elem
-static Sym*
-decodetype_ptrelem(Sym *s)
-{
-	return decode_reloc_sym(s, CommonSize);	// 0x1c / 0x30
-}
-
-// Type.MapType.key, elem
-static Sym*
-decodetype_mapkey(Sym *s)
-{
-	return decode_reloc_sym(s, CommonSize);	// 0x1c / 0x30
-}
-static Sym*
-decodetype_mapvalue(Sym *s)
-{
-	return decode_reloc_sym(s, CommonSize+PtrSize);	// 0x20 / 0x38
-}
-
-// Type.ChanType.elem
-static Sym*
-decodetype_chanelem(Sym *s)
-{
-	return decode_reloc_sym(s, CommonSize);	// 0x1c / 0x30
-}
-
-// Type.FuncType.dotdotdot
-static int
-decodetype_funcdotdotdot(Sym *s)
-{
-	return s->p[CommonSize];
-}
-
-// Type.FuncType.in.len
-static int
-decodetype_funcincount(Sym *s)
-{
-	return decode_inuxi(s->p + CommonSize+2*PtrSize, 4);
-}
-
-static int
-decodetype_funcoutcount(Sym *s)
-{
-	return decode_inuxi(s->p + CommonSize+3*PtrSize + 2*4, 4);
-}
-
-static Sym*
-decodetype_funcintype(Sym *s, int i)
-{
-	Reloc *r;
-
-	r = decode_reloc(s, CommonSize + PtrSize);
-	if (r == nil)
-		return nil;
-	return decode_reloc_sym(r->sym, r->add + i * PtrSize);
-}
-
-static Sym*
-decodetype_funcouttype(Sym *s, int i)
-{
-	Reloc *r;
-
-	r = decode_reloc(s, CommonSize + 2*PtrSize + 2*4);
-	if (r == nil)
-		return nil;
-	return decode_reloc_sym(r->sym, r->add + i * PtrSize);
-}
-
-// Type.StructType.fields.Slice::len
-static int
-decodetype_structfieldcount(Sym *s)
-{
-	return decode_inuxi(s->p + CommonSize + PtrSize, 4);
-}
-
-enum {
-	StructFieldSize = 5*PtrSize
-};
-// Type.StructType.fields[]-> name, typ and offset.
-static char*
-decodetype_structfieldname(Sym *s, int i)
-{
-	Reloc *r;
-
-	// go.string."foo"  0x28 / 0x40
-	s = decode_reloc_sym(s, CommonSize + PtrSize + 2*4 + i*StructFieldSize);
-	if (s == nil)			// embedded structs have a nil name.
-		return nil;
-	r = decode_reloc(s, 0);		// s has a pointer to the string data at offset 0
-	if (r == nil)			// shouldn't happen.
-		return nil;
-	return (char*) r->sym->p + r->add;	// the c-string
-}
-
-static Sym*
-decodetype_structfieldtype(Sym *s, int i)
-{
-	return decode_reloc_sym(s, CommonSize + PtrSize + 2*4 + i*StructFieldSize + 2*PtrSize);
-}
-
-static vlong
-decodetype_structfieldoffs(Sym *s, int i)
-{
-	return decode_inuxi(s->p + CommonSize + PtrSize + 2*4 + i*StructFieldSize + 4*PtrSize, 4);
-}
-
-// InterfaceTYpe.methods.len
-static vlong
-decodetype_ifacemethodcount(Sym *s)
-{
-	return decode_inuxi(s->p + CommonSize + PtrSize, 4);
-}
-
 
 // Fake attributes for slices, maps and channel
 enum {

src/cmd/ld/lib.h

@@ -39,6 +39,8 @@ enum
 	SSTRING,
 	SGOSTRING,
 	SRODATA,
+	SGCDATA,
+	SGCBSS,
 	SSYMTAB,
 	SPCLNTAB,
 	SELFROSECT,
@@ -186,14 +188,18 @@ void	savedata(Sym*, Prog*, char*);
 void	symgrow(Sym*, int32);
 void	addstrdata(char*, char*);
 vlong	addstring(Sym*, char*);
+vlong	adduint8(Sym*, uint8);
+vlong	adduint16(Sym*, uint16);
 vlong	adduint32(Sym*, uint32);
 vlong	adduint64(Sym*, uint64);
 vlong	addaddr(Sym*, Sym*);
 vlong	addaddrplus(Sym*, Sym*, int32);
 vlong	addpcrelplus(Sym*, Sym*, int32);
 vlong	addsize(Sym*, Sym*);
-vlong	adduint8(Sym*, uint8);
+void	setuint8(Sym*, vlong, uint8);
-vlong	adduint16(Sym*, uint16);
+void	setuint16(Sym*, vlong, uint16);
+void	setuint32(Sym*, vlong, uint32);
+void	setuint64(Sym*, vlong, uint64);
 void	asmsym(void);
 void	asmelfsym(void);
 void	asmplan9sym(void);
@@ -315,3 +321,23 @@ void	cseek(vlong);
 void	cwrite(void*, int);
 void	importcycles(void);
 int	Zconv(Fmt*);
+
+uint8	decodetype_kind(Sym*);
+vlong	decodetype_size(Sym*);
+Sym*	decodetype_gc(Sym*);
+Sym*	decodetype_arrayelem(Sym*);
+vlong	decodetype_arraylen(Sym*);
+Sym*	decodetype_ptrelem(Sym*);
+Sym*	decodetype_mapkey(Sym*);
+Sym*	decodetype_mapvalue(Sym*);
+Sym*	decodetype_chanelem(Sym*);
+int	decodetype_funcdotdotdot(Sym*);
+int	decodetype_funcincount(Sym*);
+int	decodetype_funcoutcount(Sym*);
+Sym*	decodetype_funcintype(Sym*, int);
+Sym*	decodetype_funcouttype(Sym*, int);
+int	decodetype_structfieldcount(Sym*);
+char*	decodetype_structfieldname(Sym*, int);
+Sym*	decodetype_structfieldtype(Sym*, int);
+vlong	decodetype_structfieldoffs(Sym*, int);
+vlong	decodetype_ifacemethodcount(Sym*);

src/cmd/ld/symtab.c

@@ -339,6 +339,10 @@ symtab(void)
 	xdefine("etext", STEXT, 0);
 	xdefine("rodata", SRODATA, 0);
 	xdefine("erodata", SRODATA, 0);
+	xdefine("gcdata", SGCDATA, 0);
+	xdefine("egcdata", SGCDATA, 0);
+	xdefine("gcbss", SGCBSS, 0);
+	xdefine("egcbss", SGCBSS, 0);
 	xdefine("noptrdata", SNOPTRDATA, 0);
 	xdefine("enoptrdata", SNOPTRDATA, 0);
 	xdefine("data", SDATA, 0);