[dev.link] cmd/internal/obj: restore old DWARF symbol handling

When old object file format is used, serialize DWARF symbols in
the old way.

Change-Id: I73a97f10bba367ac29c52f8f3d0f8f3b34a42523
Reviewed-on: https://go-review.googlesource.com/c/go/+/224624
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>

diff --git a/src/cmd/internal/obj/objfile.go b/src/cmd/internal/obj/objfile.go
index c0f8f9bbb864afbee8768a6bb1566e5b603390bd..3e97c614b886de70baa7765b0c72aba42bd132cd 100644 (file)
--- a/src/cmd/internal/obj/objfile.go
+++ b/src/cmd/internal/obj/objfile.go
@@ -507,11 +507,17 @@ func (c dwCtxt) AddDWARFAddrSectionOffset(s dwarf.Sym, t interface{}, ofs int64)
 func (c dwCtxt) AddFileRef(s dwarf.Sym, f interface{}) {
        ls := s.(*LSym)
        rsym := f.(*LSym)
-       fidx := c.Link.PosTable.FileIndex(rsym.Name)
-       // Note the +1 here -- the value we're writing is going to be an
-       // index into the DWARF line table file section, whose entries
-       // are numbered starting at 1, not 0.
-       ls.WriteInt(c.Link, ls.Size, 4, int64(fidx+1))
+       if c.Link.Flag_go115newobj {
+               fidx := c.Link.PosTable.FileIndex(rsym.Name)
+               // Note the +1 here -- the value we're writing is going to be an
+               // index into the DWARF line table file section, whose entries
+               // are numbered starting at 1, not 0.
+               ls.WriteInt(c.Link, ls.Size, 4, int64(fidx+1))
+       } else {
+               ls.WriteAddr(c.Link, ls.Size, 4, rsym, 0)
+               r := &ls.R[len(ls.R)-1]
+               r.Type = objabi.R_DWARFFILEREF
+       }
 }
 
 func (c dwCtxt) CurrentOffset(s dwarf.Sym) int64 {
@@ -549,23 +555,32 @@ func (ctxt *Link) dwarfSym(s *LSym) (dwarfInfoSym, dwarfLocSym, dwarfRangesSym,
                ctxt.Diag("dwarfSym of non-TEXT %v", s)
        }
        if s.Func.dwarfInfoSym == nil {
-               s.Func.dwarfInfoSym = &LSym{
-                       Type: objabi.SDWARFINFO,
-               }
-               if ctxt.Flag_locationlists {
-                       s.Func.dwarfLocSym = &LSym{
-                               Type: objabi.SDWARFLOC,
+               if ctxt.Flag_go115newobj {
+                       s.Func.dwarfInfoSym = &LSym{
+                               Type: objabi.SDWARFINFO,
                        }
-               }
-               s.Func.dwarfRangesSym = &LSym{
-                       Type: objabi.SDWARFRANGE,
+                       if ctxt.Flag_locationlists {
+                               s.Func.dwarfLocSym = &LSym{
+                                       Type: objabi.SDWARFLOC,
+                               }
+                       }
+                       s.Func.dwarfRangesSym = &LSym{
+                               Type: objabi.SDWARFRANGE,
+                       }
+                       s.Func.dwarfDebugLinesSym = &LSym{
+                               Type: objabi.SDWARFLINES,
+                       }
+               } else {
+                       s.Func.dwarfInfoSym = ctxt.LookupDerived(s, dwarf.InfoPrefix+s.Name)
+                       if ctxt.Flag_locationlists {
+                               s.Func.dwarfLocSym = ctxt.LookupDerived(s, dwarf.LocPrefix+s.Name)
+                       }
+                       s.Func.dwarfRangesSym = ctxt.LookupDerived(s, dwarf.RangePrefix+s.Name)
+                       s.Func.dwarfDebugLinesSym = ctxt.LookupDerived(s, dwarf.DebugLinesPrefix+s.Name)
                }
                if s.WasInlined() {
                        s.Func.dwarfAbsFnSym = ctxt.DwFixups.AbsFuncDwarfSym(s)
                }
-               s.Func.dwarfDebugLinesSym = &LSym{
-                       Type: objabi.SDWARFLINES,
-               }
        }
        return s.Func.dwarfInfoSym, s.Func.dwarfLocSym, s.Func.dwarfRangesSym, s.Func.dwarfAbsFnSym, s.Func.dwarfDebugLinesSym
 }

diff --git a/src/cmd/internal/obj/plist.go b/src/cmd/internal/obj/plist.go
index 57438d57eaaabb7cd8c4d73711bab00d0cecd158..44ec4602decf107684ec9d4e78caceb89ca25c4f 100644 (file)
--- a/src/cmd/internal/obj/plist.go
+++ b/src/cmd/internal/obj/plist.go
@@ -138,8 +138,27 @@ func (ctxt *Link) InitTextSym(s *LSym, flag int) {
        s.Type = objabi.STEXT
        ctxt.Text = append(ctxt.Text, s)
 
-       // Set up DWARF entries for s.
-       ctxt.dwarfSym(s)
+       // Set up DWARF entries for s
+       info, loc, ranges, _, lines := ctxt.dwarfSym(s)
+
+       // When using new object files, the DWARF symbols are unnamed aux
+       // symbols and don't need to be added to ctxt.Data.
+       // But the old object file still needs them.
+       if !ctxt.Flag_go115newobj {
+               info.Type = objabi.SDWARFINFO
+               info.Set(AttrDuplicateOK, s.DuplicateOK())
+               if loc != nil {
+                       loc.Type = objabi.SDWARFLOC
+                       loc.Set(AttrDuplicateOK, s.DuplicateOK())
+                       ctxt.Data = append(ctxt.Data, loc)
+               }
+               ranges.Type = objabi.SDWARFRANGE
+               ranges.Set(AttrDuplicateOK, s.DuplicateOK())
+               ctxt.Data = append(ctxt.Data, info, ranges)
+               lines.Type = objabi.SDWARFLINES
+               lines.Set(AttrDuplicateOK, s.DuplicateOK())
+               ctxt.Data = append(ctxt.Data, lines)
+       }
 }
 
 func (ctxt *Link) Globl(s *LSym, size int64, flag int) {