cmd/compile: add new symbol for debug line numbers

This is broken out from: CL 187117

This new symbol will be populated by the compiler and contain debug line
information that's currently generated in the linker. One might say it's
sad to create a new symbol, but this symbol will replace the isStmt
symbols.

Testing: Ran go build -toolexec 'toolstash -cmp'

Change-Id: If8f7ae4b43b7247076605b6429b7d03a1fd239c5
Reviewed-on: https://go-review.googlesource.com/c/go/+/188238
Reviewed-by: Austin Clements <austin@google.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/src/cmd/internal/obj/objfile.go b/src/cmd/internal/obj/objfile.go
index a3281a99e4..65803ae29a 100644
--- a/src/cmd/internal/obj/objfile.go
+++ b/src/cmd/internal/obj/objfile.go
@@ -537,7 +537,7 @@ func isDwarf64(ctxt *Link) bool {
 	return ctxt.Headtype == objabi.Haix
 }
 
-func (ctxt *Link) dwarfSym(s *LSym) (dwarfInfoSym, dwarfLocSym, dwarfRangesSym, dwarfAbsFnSym, dwarfIsStmtSym *LSym) {
+func (ctxt *Link) dwarfSym(s *LSym) (dwarfInfoSym, dwarfLocSym, dwarfRangesSym, dwarfAbsFnSym, dwarfIsStmtSym, dwarfDebugLines *LSym) {
 	if s.Type != objabi.STEXT {
 		ctxt.Diag("dwarfSym of non-TEXT %v", s)
 	}
@@ -551,9 +551,9 @@ func (ctxt *Link) dwarfSym(s *LSym) (dwarfInfoSym, dwarfLocSym, dwarfRangesSym,
 			s.Func.dwarfAbsFnSym = ctxt.DwFixups.AbsFuncDwarfSym(s)
 		}
 		s.Func.dwarfIsStmtSym = ctxt.LookupDerived(s, dwarf.IsStmtPrefix+s.Name)
-
+		s.Func.dwarfDebugLinesSym = ctxt.LookupDerived(s, dwarf.DebugLinesPrefix+s.Name)
 	}
-	return s.Func.dwarfInfoSym, s.Func.dwarfLocSym, s.Func.dwarfRangesSym, s.Func.dwarfAbsFnSym, s.Func.dwarfIsStmtSym
+	return s.Func.dwarfInfoSym, s.Func.dwarfLocSym, s.Func.dwarfRangesSym, s.Func.dwarfAbsFnSym, s.Func.dwarfIsStmtSym, s.Func.dwarfDebugLinesSym
 }
 
 func (s *LSym) Len() int64 {
@@ -577,7 +577,7 @@ func (ctxt *Link) fileSymbol(fn *LSym) *LSym {
 // TEXT symbol 's'. The various DWARF symbols must already have been
 // initialized in InitTextSym.
 func (ctxt *Link) populateDWARF(curfn interface{}, s *LSym, myimportpath string) {
-	info, loc, ranges, absfunc, _ := ctxt.dwarfSym(s)
+	info, loc, ranges, absfunc, _, _ := ctxt.dwarfSym(s)
 	if info.Size != 0 {
 		ctxt.Diag("makeFuncDebugEntry double process %v", s)
 	}