1// Copyright 2009 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5package objw
6
7import (
8	"cmd/compile/internal/base"
9	"cmd/compile/internal/bitvec"
10	"cmd/compile/internal/types"
11	"cmd/internal/obj"
12	"encoding/binary"
13)
14
15// Uint8 writes an unsigned byte v into s at offset off,
16// and returns the next unused offset (i.e., off+1).
17func Uint8(s *obj.LSym, off int, v uint8) int {
18	return UintN(s, off, uint64(v), 1)
19}
20
21func Uint16(s *obj.LSym, off int, v uint16) int {
22	return UintN(s, off, uint64(v), 2)
23}
24
25func Uint32(s *obj.LSym, off int, v uint32) int {
26	return UintN(s, off, uint64(v), 4)
27}
28
29func Uintptr(s *obj.LSym, off int, v uint64) int {
30	return UintN(s, off, v, types.PtrSize)
31}
32
33// Uvarint writes a varint v into s at offset off,
34// and returns the next unused offset.
35func Uvarint(s *obj.LSym, off int, v uint64) int {
36	var buf [binary.MaxVarintLen64]byte
37	n := binary.PutUvarint(buf[:], v)
38	return int(s.WriteBytes(base.Ctxt, int64(off), buf[:n]))
39}
40
41func Bool(s *obj.LSym, off int, v bool) int {
42	w := 0
43	if v {
44		w = 1
45	}
46	return UintN(s, off, uint64(w), 1)
47}
48
49// UintN writes an unsigned integer v of size wid bytes into s at offset off,
50// and returns the next unused offset.
51func UintN(s *obj.LSym, off int, v uint64, wid int) int {
52	if off&(wid-1) != 0 {
53		base.Fatalf("duintxxLSym: misaligned: v=%d wid=%d off=%d", v, wid, off)
54	}
55	s.WriteInt(base.Ctxt, int64(off), wid, int64(v))
56	return off + wid
57}
58
59func SymPtr(s *obj.LSym, off int, x *obj.LSym, xoff int) int {
60	off = int(types.RoundUp(int64(off), int64(types.PtrSize)))
61	s.WriteAddr(base.Ctxt, int64(off), types.PtrSize, x, int64(xoff))
62	off += types.PtrSize
63	return off
64}
65
66func SymPtrWeak(s *obj.LSym, off int, x *obj.LSym, xoff int) int {
67	off = int(types.RoundUp(int64(off), int64(types.PtrSize)))
68	s.WriteWeakAddr(base.Ctxt, int64(off), types.PtrSize, x, int64(xoff))
69	off += types.PtrSize
70	return off
71}
72
73func SymPtrOff(s *obj.LSym, off int, x *obj.LSym) int {
74	s.WriteOff(base.Ctxt, int64(off), x, 0)
75	off += 4
76	return off
77}
78
79func SymPtrWeakOff(s *obj.LSym, off int, x *obj.LSym) int {
80	s.WriteWeakOff(base.Ctxt, int64(off), x, 0)
81	off += 4
82	return off
83}
84
85func Global(s *obj.LSym, width int32, flags int16) {
86	if flags&obj.LOCAL != 0 {
87		s.Set(obj.AttrLocal, true)
88		flags &^= obj.LOCAL
89	}
90	base.Ctxt.Globl(s, int64(width), int(flags))
91}
92
93// BitVec writes the contents of bv into s as sequence of bytes
94// in little-endian order, and returns the next unused offset.
95func BitVec(s *obj.LSym, off int, bv bitvec.BitVec) int {
96	// Runtime reads the bitmaps as byte arrays. Oblige.
97	for j := 0; int32(j) < bv.N; j += 8 {
98		word := bv.B[j/32]
99		off = Uint8(s, off, uint8(word>>(uint(j)%32)))
100	}
101	return off
102}
103