cmd/internal/obj: replace obj.Addrel func with LSym.AddRel method

The old API was to do

	r := obj.AddRel(sym)
	r.Type = this
	r.Off = that
	etc

The new API is:

	sym.AddRel(ctxt, obj.Reloc{Type: this: Off: that, etc})

This new API is more idiomatic and avoids ever having relocations
that are only partially constructed. Most importantly, it sets up
for sym.AddRel being able to check relocation validity in the future.
(Passing ctxt is for use in validity checking.)

Passes golang.org/x/tools/cmd/toolstash/buildall.

Change-Id: I042ea76e61bb3bf6402f98ca11291a13f4799972
Reviewed-on: https://go-review.googlesource.com/c/go/+/625616
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>

1 files changed, 28 insertions, 28 deletions

diff --git a/src/cmd/internal/obj/data.go b/src/cmd/internal/obj/data.go
index bcba53c3a4..361ea05a0f 100644
--- a/src/cmd/internal/obj/data.go
+++ b/src/cmd/internal/obj/data.go
@@ -118,15 +118,16 @@ func (s *LSym) writeAddr(ctxt *Link, off int64, siz int, rsym *LSym, roff int64,
 		ctxt.Diag("WriteAddr: bad address size %d in %s", siz, s.Name)
 	}
 	s.prepwrite(ctxt, off, siz)
-	r := Addrel(s)
-	r.Off = int32(off)
-	if int64(r.Off) != off {
+	if int64(int32(off)) != off {
 		ctxt.Diag("WriteAddr: off overflow %d in %s", off, s.Name)
 	}
-	r.Siz = uint8(siz)
-	r.Sym = rsym
-	r.Type = rtype
-	r.Add = roff
+	s.AddRel(ctxt, Reloc{
+		Type: rtype,
+		Off:  int32(off),
+		Siz:  uint8(siz),
+		Sym:  rsym,
+		Add:  roff,
+	})
 }
 
 // WriteAddr writes an address of size siz into s at offset off.
@@ -155,15 +156,16 @@ func (s *LSym) WriteCURelativeAddr(ctxt *Link, off int64, rsym *LSym, roff int64
 // rsym+roff-(start of section that s is in).
 func (s *LSym) WriteOff(ctxt *Link, off int64, rsym *LSym, roff int64) {
 	s.prepwrite(ctxt, off, 4)
-	r := Addrel(s)
-	r.Off = int32(off)
-	if int64(r.Off) != off {
+	if int64(int32(off)) != off {
 		ctxt.Diag("WriteOff: off overflow %d in %s", off, s.Name)
 	}
-	r.Siz = 4
-	r.Sym = rsym
-	r.Type = objabi.R_ADDROFF
-	r.Add = roff
+	s.AddRel(ctxt, Reloc{
+		Type: objabi.R_ADDROFF,
+		Off:  int32(off),
+		Siz:  4,
+		Sym:  rsym,
+		Add:  roff,
+	})
 }
 
 // WriteWeakOff writes a weak 4 byte offset to rsym+roff into s at offset off.
@@ -171,15 +173,16 @@ func (s *LSym) WriteOff(ctxt *Link, off int64, rsym *LSym, roff int64) {
 // rsym+roff-(start of section that s is in).
 func (s *LSym) WriteWeakOff(ctxt *Link, off int64, rsym *LSym, roff int64) {
 	s.prepwrite(ctxt, off, 4)
-	r := Addrel(s)
-	r.Off = int32(off)
-	if int64(r.Off) != off {
-		ctxt.Diag("WriteOff: off overflow %d in %s", off, s.Name)
+	if int64(int32(off)) != off {
+		ctxt.Diag("WriteWeakOff: off overflow %d in %s", off, s.Name)
 	}
-	r.Siz = 4
-	r.Sym = rsym
-	r.Type = objabi.R_WEAKADDROFF
-	r.Add = roff
+	s.AddRel(ctxt, Reloc{
+		Type: objabi.R_WEAKADDROFF,
+		Off:  int32(off),
+		Siz:  4,
+		Sym:  rsym,
+		Add:  roff,
+	})
 }
 
 // WriteString writes a string of size siz into s at offset off.
@@ -198,10 +201,7 @@ func (s *LSym) WriteBytes(ctxt *Link, off int64, b []byte) int64 {
 	return off + int64(len(b))
 }
 
-func Addrel(s *LSym) *Reloc {
-	if s.R == nil {
-		s.R = make([]Reloc, 0, 4)
-	}
-	s.R = append(s.R, Reloc{})
-	return &s.R[len(s.R)-1]
+// AddRel adds the relocation rel to s.
+func (s *LSym) AddRel(ctxt *Link, rel Reloc) {
+	s.R = append(s.R, rel)
 }