From 059c10b552d8e8331a5621fa73d1fcb914cc913e Mon Sep 17 00:00:00 2001
From: Keith Randall <khr@golang.org>
Date: Wed, 2 Apr 2014 19:46:47 -0700
Subject: [PATCH] cmd/ld: get rid of map.bucket's data field from dwarf info.

The data field is the generic array that acts as a standin
for the keys and values arrays for the generic runtime code.
We want to substitute the keys and values arrays for the data
array, not just add keys and values in addition to it.

LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/81160044
---
 src/cmd/ld/dwarf.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/src/cmd/ld/dwarf.c b/src/cmd/ld/dwarf.c
index fe1576bf519..9966cc8d1f9 100644
--- a/src/cmd/ld/dwarf.c
+++ b/src/cmd/ld/dwarf.c
@@ -1099,21 +1099,29 @@ defptrto(DWDie *dwtype)
 }
 
 // Copies src's children into dst. Copies attributes by value.
-// DWAttr.data is copied as pointer only.
+// DWAttr.data is copied as pointer only.  If except is one of
+// the top-level children, it will not be copied.
 static void
-copychildren(DWDie *dst, DWDie *src)
+copychildrenexcept(DWDie *dst, DWDie *src, DWDie *except)
 {
 	DWDie *c;
 	DWAttr *a;
 
 	for (src = src->child; src != nil; src = src->link) {
+		if(src == except)
+			continue;
 		c = newdie(dst, src->abbrev, getattr(src, DW_AT_name)->data);
 		for (a = src->attr; a != nil; a = a->link)
 			newattr(c, a->atr, a->cls, a->value, a->data);
-		copychildren(c, src);
+		copychildrenexcept(c, src, nil);
 	}
 	reverselist(&dst->child);
 }
+static void
+copychildren(DWDie *dst, DWDie *src)
+{
+	copychildrenexcept(dst, src, nil);
+}
 
 // Search children (assumed to have DW_TAG_member) for the one named
 // field and set its DW_AT_type to dwtype
@@ -1253,7 +1261,10 @@ synthesizemaptypes(DWDie *die)
 			      mkinternaltypename("bucket",
 						 getattr(keytype, DW_AT_name)->data,
 						 getattr(valtype, DW_AT_name)->data));
-		copychildren(dwhb, bucket);
+		// Copy over all fields except the field "data" from the generic bucket.
+		// "data" will be replaced with keys/values below.
+		copychildrenexcept(dwhb, bucket, find(bucket, "data"));
+		
 		fld = newdie(dwhb, DW_ABRV_STRUCTFIELD, "keys");
 		newrefattr(fld, DW_AT_type, dwhk);
 		newmemberoffsetattr(fld, BucketSize + PtrSize);