Revert "cmd/compile: output DWARF lexical blocks for local variables"

This reverts commit c8b889cc4824f4dbd64a51a3f7b5b6dce4b87ed2.

Reason for revert: broke noopt build, compiler performance regression, new Curfn uses

Let's fix those and then try this again.

Change-Id: Icc3cad1365d04cac8fd09da9dbb0bbf55c13ef44
Reviewed-on: https://go-review.googlesource.com/39991
Reviewed-by: Robert Griesemer <gri@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

3 files changed, 8 insertions, 28 deletions

diff --git a/src/cmd/internal/obj/data.go b/src/cmd/internal/obj/data.go
index 7a19e3a38c..114841dedb 100644
--- a/src/cmd/internal/obj/data.go
+++ b/src/cmd/internal/obj/data.go
@@ -114,7 +114,7 @@ func (s *LSym) WriteInt(ctxt *Link, off int64, siz int, i int64) {
 // WriteAddr writes an address of size siz into s at offset off.
 // rsym and roff specify the relocation for the address.
 func (s *LSym) WriteAddr(ctxt *Link, off int64, siz int, rsym *LSym, roff int64) {
-	if siz != ctxt.Arch.PtrSize && siz != 4 {
+	if siz != ctxt.Arch.PtrSize {
 		ctxt.Diag("WriteAddr: bad address size %d in %s", siz, s.Name)
 	}
 	s.prepwrite(ctxt, off, siz)
diff --git a/src/cmd/internal/obj/link.go b/src/cmd/internal/obj/link.go
index e08d7a0340..fd07851f3b 100644
--- a/src/cmd/internal/obj/link.go
+++ b/src/cmd/internal/obj/link.go
@@ -483,7 +483,6 @@ const (
 	SHOSTOBJ
 	SDWARFSECT
 	SDWARFINFO
-	SDWARFRANGE
 	SSUB       = SymKind(1 << 8)
 	SMASK      = SymKind(SSUB - 1)
 	SHIDDEN    = SymKind(1 << 9)
@@ -740,7 +739,7 @@ type Link struct {
 	Armsize       int32
 	Pc            int64
 	DiagFunc      func(string, ...interface{})
-	DebugInfo     func(fn *LSym, curfn interface{}) []dwarf.Scope // if non-nil, curfn is a *gc.Node
+	DebugInfo     func(fn *LSym, curfn interface{}) []*dwarf.Var // if non-nil, curfn is a *gc.Node
 	Cursym        *LSym
 	Version       int
 	Errors        int
diff --git a/src/cmd/internal/obj/objfile.go b/src/cmd/internal/obj/objfile.go
index 314c7a9de6..6858143674 100644
--- a/src/cmd/internal/obj/objfile.go
+++ b/src/cmd/internal/obj/objfile.go
@@ -542,14 +542,10 @@ func (c dwCtxt) SymValue(s dwarf.Sym) int64 {
 	return 0
 }
 func (c dwCtxt) AddAddress(s dwarf.Sym, data interface{}, value int64) {
+	rsym := data.(*LSym)
 	ls := s.(*LSym)
 	size := c.PtrSize()
-	if data != nil {
-		rsym := data.(*LSym)
-		ls.WriteAddr(c.Link, ls.Size, size, rsym, value)
-	} else {
-		ls.WriteInt(c.Link, ls.Size, size, value)
-	}
+	ls.WriteAddr(c.Link, ls.Size, size, rsym, value)
 }
 func (c dwCtxt) AddSectionOffset(s dwarf.Sym, size int, t interface{}, ofs int64) {
 	ls := s.(*LSym)
@@ -559,10 +555,6 @@ func (c dwCtxt) AddSectionOffset(s dwarf.Sym, size int, t interface{}, ofs int64
 	r.Type = R_DWARFREF
 }
 
-func (s *LSym) Len() int64 {
-	return s.Size
-}
-
 // makeFuncDebugEntry makes a DWARF Debugging Information Entry
 // for TEXT symbol s.
 func makeFuncDebugEntry(ctxt *Link, curfn interface{}, s *LSym) {
@@ -572,21 +564,10 @@ func makeFuncDebugEntry(ctxt *Link, curfn interface{}, s *LSym) {
 	}
 	dsym.Type = SDWARFINFO
 	dsym.Set(AttrDuplicateOK, s.DuplicateOK())
-
-	drsym := ctxt.Lookup(dwarf.RangePrefix+s.Name, int(s.Version))
-	if drsym.Size != 0 {
-		return
-	}
-	drsym.Type = SDWARFRANGE
-	drsym.Set(AttrDuplicateOK, s.DuplicateOK())
-
-	var scopes []dwarf.Scope
+	var vars []*dwarf.Var
 	if ctxt.DebugInfo != nil {
-		scopes = ctxt.DebugInfo(s, curfn)
-	}
-	err := dwarf.PutFunc(dwCtxt{ctxt}, dsym, drsym, s.Name, s.Version == 0, s, s.Size, scopes)
-	if err != nil {
-		ctxt.Diag("emitting DWARF for %s failed: %v", s.Name, err)
+		vars = ctxt.DebugInfo(s, curfn)
 	}
-	ctxt.Data = append(ctxt.Data, dsym, drsym)
+	dwarf.PutFunc(dwCtxt{ctxt}, dsym, s.Name, s.Version == 0, s, s.Size, vars)
+	ctxt.Data = append(ctxt.Data, dsym)
 }