From c75884185332458242c03b17014bc3801977f684 Mon Sep 17 00:00:00 2001
From: Russ Cox <rsc@golang.org>
Date: Fri, 19 Jul 2013 18:52:35 -0400
Subject: [PATCH] cmd/ld, runtime: remove unused fields from Func

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/11604043
---
 src/cmd/ld/lib.c               |  9 +--------
 src/libmach/sym.c              | 25 +++++++++++++++++--------
 src/pkg/debug/gosym/pclntab.go |  8 ++++----
 src/pkg/runtime/runtime.h      |  5 +----
 4 files changed, 23 insertions(+), 24 deletions(-)

diff --git a/src/cmd/ld/lib.c b/src/cmd/ld/lib.c
index 674a1297759..49f2bc304c8 100644
--- a/src/cmd/ld/lib.c
+++ b/src/cmd/ld/lib.c
@@ -2400,7 +2400,7 @@ pclntab(void)
 
 		// fixed size of struct, checked below
 		off = funcstart;
-		end = funcstart + PtrSize + 6*4 + 5*4 + npcdata*4 + nfuncdata*PtrSize;
+		end = funcstart + PtrSize + 3*4 + 5*4 + npcdata*4 + nfuncdata*PtrSize;
 		if(nfuncdata > 0 && (end&(PtrSize-1)))
 			end += 4;
 		symgrow(ftab, end);
@@ -2417,9 +2417,6 @@ pclntab(void)
 			off = setuint32(ftab, off, ArgsSizeUnknown);
 		else
 			off = setuint32(ftab, off, cursym->args);
-
-		// Dead space. TODO: Delete (and update all parsers).
-		off = setuint32(ftab, off, 0);
 	
 		// frame int32
 		// TODO: Remove entirely. The pcsp table is more precise.
@@ -2432,10 +2429,6 @@ pclntab(void)
 		else
 			off = setuint32(ftab, off, (uint32)cursym->text->to.offset+PtrSize);
 
-		// Dead space. TODO: Delete (and update all parsers).
-		off = setuint32(ftab, off, 0);
-		off = setuint32(ftab, off, 0);
-
 		// pcsp table (offset int32)
 		off = addpctab(ftab, off, cursym, "pctospadj", pctospadj, 0);
 
diff --git a/src/libmach/sym.c b/src/libmach/sym.c
index d8cd8ea1d9e..b9732012f2c 100644
--- a/src/libmach/sym.c
+++ b/src/libmach/sym.c
@@ -1563,6 +1563,15 @@ dumphist(char *name)
 // Go 1.2 pcln table
 // See golang.org/s/go12symtab.
 
+// Func layout
+#define FuncEntry (0)
+#define FuncName (pcptrsize)
+#define FuncArgs (pcptrsize+4)
+#define FuncFrame (pcptrsize+2*4)
+#define FuncPCSP (pcptrsize+3*4)
+#define FuncPCFile (pcptrsize+4*4)
+#define FuncPCLine (pcptrsize+5*4)
+
 static int32 pcquantum;
 static int32 pcptrsize;
 static uvlong (*pcswav)(uvlong);
@@ -1788,8 +1797,8 @@ go12pc2sp(uvlong pc)
 	f = go12findfunc(pc);
 	if(f == nil)
 		return ~(uvlong)0;
-	entry = pcuintptr(f);
-	off = pcswal(*(uint32*)(f+pcptrsize+6*4));
+	entry = pcuintptr(f+FuncEntry);
+	off = pcswal(*(uint32*)(f+FuncPCSP));
 	sp = pcvalue(off, entry, pc);
 	if(sp < 0)
 		return ~(uvlong)0;
@@ -1807,9 +1816,9 @@ go12fileline(char *str, int n, uvlong pc)
 	f = go12findfunc(pc);
 	if(f == nil)
 		return 0;
-	entry = pcuintptr(f);
-	fileoff = pcswal(*(uint32*)(f+pcptrsize+7*4));
-	lineoff = pcswal(*(uint32*)(f+pcptrsize+8*4));
+	entry = pcuintptr(f+FuncEntry);
+	fileoff = pcswal(*(uint32*)(f+FuncPCFile));
+	lineoff = pcswal(*(uint32*)(f+FuncPCLine));
 	lno = pcvalue(lineoff, entry, pc);
 	fno = pcvalue(fileoff, entry, pc);
 	if(lno < 0 || fno <= 0 || fno >= nfiletab) {
@@ -1845,9 +1854,9 @@ havefile:
 	// quick.
 	for(i=0; i<nfunctab; i++) {
 		func = pcline + pcuintptr(functab+i*2*pcptrsize+pcptrsize);
-		entry = pcuintptr(func);
-		fp = pcline + pcswal(*(uint32*)(func+pcptrsize+7*4));
-		lp = pcline + pcswal(*(uint32*)(func+pcptrsize+8*4));
+		entry = pcuintptr(func+FuncEntry);
+		fp = pcline + pcswal(*(uint32*)(func+FuncPCFile));
+		lp = pcline + pcswal(*(uint32*)(func+FuncPCLine));
 		fval = lval = -1;
 		fpc = lpc = entry;
 		fstartpc = fpc;
diff --git a/src/pkg/debug/gosym/pclntab.go b/src/pkg/debug/gosym/pclntab.go
index 2b9bedb45bc..3e6a8046b3e 100644
--- a/src/pkg/debug/gosym/pclntab.go
+++ b/src/pkg/debug/gosym/pclntab.go
@@ -339,7 +339,7 @@ func (t *LineTable) go12PCToLine(pc uint64) (line int) {
 		return -1
 	}
 	entry := t.uintptr(f)
-	linetab := t.binary.Uint32(f[t.ptrsize+8*4:])
+	linetab := t.binary.Uint32(f[t.ptrsize+5*4:])
 	return int(t.pcvalue(linetab, entry, pc))
 }
 
@@ -356,7 +356,7 @@ func (t *LineTable) go12PCToFile(pc uint64) (file string) {
 		return ""
 	}
 	entry := t.uintptr(f)
-	filetab := t.binary.Uint32(f[t.ptrsize+7*4:])
+	filetab := t.binary.Uint32(f[t.ptrsize+4*4:])
 	fno := t.pcvalue(filetab, entry, pc)
 	if fno <= 0 {
 		return ""
@@ -384,8 +384,8 @@ func (t *LineTable) go12LineToPC(file string, line int) (pc uint64) {
 	for i := uint32(0); i < t.nfunctab; i++ {
 		f := t.Data[t.uintptr(t.functab[2*t.ptrsize*i+t.ptrsize:]):]
 		entry := t.uintptr(f)
-		filetab := t.binary.Uint32(f[t.ptrsize+7*4:])
-		linetab := t.binary.Uint32(f[t.ptrsize+8*4:])
+		filetab := t.binary.Uint32(f[t.ptrsize+4*4:])
+		linetab := t.binary.Uint32(f[t.ptrsize+5*4:])
 		pc := t.findFileLine(entry, filetab, linetab, int32(filenum), int32(line))
 		if pc != 0 {
 			return pc
diff --git a/src/pkg/runtime/runtime.h b/src/pkg/runtime/runtime.h
index f405287aa86..36aff04ad38 100644
--- a/src/pkg/runtime/runtime.h
+++ b/src/pkg/runtime/runtime.h
@@ -405,12 +405,9 @@ struct	Func
 	uintptr	entry;	// start pc
 	int32	nameoff;	// function name
 	
-	// TODO: Remove these fields.
+	// TODO: Perhaps remove these fields.
 	int32	args;	// in/out args size
-	int32	x1;	// locals size
 	int32	frame;	// legacy frame size; use pcsp if possible
-	int32	x2;
-	int32	x3;
 
 	int32	pcsp;
 	int32	pcfile;