1 files changed, 145 insertions, 0 deletions
diff --git a/src/cmd/internal/goobj/funcinfo.go b/src/cmd/internal/goobj/funcinfo.go
new file mode 100644
index 0000000..fbcf9d9
--- /dev/null
+++ b/src/cmd/internal/goobj/funcinfo.go
@@ -0,0 +1,145 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package goobj
+
+import (
+	"bytes"
+	"cmd/internal/objabi"
+	"encoding/binary"
+)
+
+// CUFileIndex is used to index the filenames that are stored in the
+// per-package/per-CU FileList.
+type CUFileIndex uint32
+
+// FuncInfo is serialized as a symbol (aux symbol). The symbol data is
+// the binary encoding of the struct below.
+type FuncInfo struct {
+	Args      uint32
+	Locals    uint32
+	FuncID    objabi.FuncID
+	FuncFlag  objabi.FuncFlag
+	StartLine int32
+	File      []CUFileIndex
+	InlTree   []InlTreeNode
+}
+
+func (a *FuncInfo) Write(w *bytes.Buffer) {
+	writeUint8 := func(x uint8) {
+		w.WriteByte(x)
+	}
+	var b [4]byte
+	writeUint32 := func(x uint32) {
+		binary.LittleEndian.PutUint32(b[:], x)
+		w.Write(b[:])
+	}
+
+	writeUint32(a.Args)
+	writeUint32(a.Locals)
+	writeUint8(uint8(a.FuncID))
+	writeUint8(uint8(a.FuncFlag))
+	writeUint8(0) // pad to uint32 boundary
+	writeUint8(0)
+	writeUint32(uint32(a.StartLine))
+
+	writeUint32(uint32(len(a.File)))
+	for _, f := range a.File {
+		writeUint32(uint32(f))
+	}
+	writeUint32(uint32(len(a.InlTree)))
+	for i := range a.InlTree {
+		a.InlTree[i].Write(w)
+	}
+}
+
+// FuncInfoLengths is a cache containing a roadmap of offsets and
+// lengths for things within a serialized FuncInfo. Each length field
+// stores the number of items (e.g. files, inltree nodes, etc), and the
+// corresponding "off" field stores the byte offset of the start of
+// the items in question.
+type FuncInfoLengths struct {
+	NumFile     uint32
+	FileOff     uint32
+	NumInlTree  uint32
+	InlTreeOff  uint32
+	Initialized bool
+}
+
+func (*FuncInfo) ReadFuncInfoLengths(b []byte) FuncInfoLengths {
+	var result FuncInfoLengths
+
+	// Offset to the number of the file table. This value is determined by counting
+	// the number of bytes until we write funcdataoff to the file.
+	const numfileOff = 16
+	result.NumFile = binary.LittleEndian.Uint32(b[numfileOff:])
+	result.FileOff = numfileOff + 4
+
+	numinltreeOff := result.FileOff + 4*result.NumFile
+	result.NumInlTree = binary.LittleEndian.Uint32(b[numinltreeOff:])
+	result.InlTreeOff = numinltreeOff + 4
+
+	result.Initialized = true
+
+	return result
+}
+
+func (*FuncInfo) ReadArgs(b []byte) uint32 { return binary.LittleEndian.Uint32(b) }
+
+func (*FuncInfo) ReadLocals(b []byte) uint32 { return binary.LittleEndian.Uint32(b[4:]) }
+
+func (*FuncInfo) ReadFuncID(b []byte) objabi.FuncID { return objabi.FuncID(b[8]) }
+
+func (*FuncInfo) ReadFuncFlag(b []byte) objabi.FuncFlag { return objabi.FuncFlag(b[9]) }
+
+func (*FuncInfo) ReadStartLine(b []byte) int32 { return int32(binary.LittleEndian.Uint32(b[12:])) }
+
+func (*FuncInfo) ReadFile(b []byte, filesoff uint32, k uint32) CUFileIndex {
+	return CUFileIndex(binary.LittleEndian.Uint32(b[filesoff+4*k:]))
+}
+
+func (*FuncInfo) ReadInlTree(b []byte, inltreeoff uint32, k uint32) InlTreeNode {
+	const inlTreeNodeSize = 4 * 6
+	var result InlTreeNode
+	result.Read(b[inltreeoff+k*inlTreeNodeSize:])
+	return result
+}
+
+// InlTreeNode is the serialized form of FileInfo.InlTree.
+type InlTreeNode struct {
+	Parent   int32
+	File     CUFileIndex
+	Line     int32
+	Func     SymRef
+	ParentPC int32
+}
+
+func (inl *InlTreeNode) Write(w *bytes.Buffer) {
+	var b [4]byte
+	writeUint32 := func(x uint32) {
+		binary.LittleEndian.PutUint32(b[:], x)
+		w.Write(b[:])
+	}
+	writeUint32(uint32(inl.Parent))
+	writeUint32(uint32(inl.File))
+	writeUint32(uint32(inl.Line))
+	writeUint32(inl.Func.PkgIdx)
+	writeUint32(inl.Func.SymIdx)
+	writeUint32(uint32(inl.ParentPC))
+}
+
+// Read an InlTreeNode from b, return the remaining bytes.
+func (inl *InlTreeNode) Read(b []byte) []byte {
+	readUint32 := func() uint32 {
+		x := binary.LittleEndian.Uint32(b)
+		b = b[4:]
+		return x
+	}
+	inl.Parent = int32(readUint32())
+	inl.File = CUFileIndex(readUint32())
+	inl.Line = int32(readUint32())
+	inl.Func = SymRef{readUint32(), readUint32()}
+	inl.ParentPC = int32(readUint32())
+	return b
+}