1 files changed, 239 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..2cca8f6
--- /dev/null
+++ b/src/cmd/internal/goobj/funcinfo.go
@@ -0,0 +1,239 @@
+// 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.
+//
+// TODO: make each pcdata a separate symbol?
+type FuncInfo struct {
+	Args   uint32
+	Locals uint32
+	FuncID objabi.FuncID
+
+	Pcsp        SymRef
+	Pcfile      SymRef
+	Pcline      SymRef
+	Pcinline    SymRef
+	Pcdata      []SymRef
+	Funcdataoff []uint32
+	File        []CUFileIndex
+
+	InlTree []InlTreeNode
+}
+
+func (a *FuncInfo) Write(w *bytes.Buffer) {
+	var b [4]byte
+	writeUint32 := func(x uint32) {
+		binary.LittleEndian.PutUint32(b[:], x)
+		w.Write(b[:])
+	}
+	writeSymRef := func(s SymRef) {
+		writeUint32(s.PkgIdx)
+		writeUint32(s.SymIdx)
+	}
+
+	writeUint32(a.Args)
+	writeUint32(a.Locals)
+	writeUint32(uint32(a.FuncID))
+
+	writeSymRef(a.Pcsp)
+	writeSymRef(a.Pcfile)
+	writeSymRef(a.Pcline)
+	writeSymRef(a.Pcinline)
+	writeUint32(uint32(len(a.Pcdata)))
+	for _, sym := range a.Pcdata {
+		writeSymRef(sym)
+	}
+
+	writeUint32(uint32(len(a.Funcdataoff)))
+	for _, x := range a.Funcdataoff {
+		writeUint32(x)
+	}
+	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)
+	}
+}
+
+func (a *FuncInfo) Read(b []byte) {
+	readUint32 := func() uint32 {
+		x := binary.LittleEndian.Uint32(b)
+		b = b[4:]
+		return x
+	}
+	readSymIdx := func() SymRef {
+		return SymRef{readUint32(), readUint32()}
+	}
+
+	a.Args = readUint32()
+	a.Locals = readUint32()
+	a.FuncID = objabi.FuncID(readUint32())
+
+	a.Pcsp = readSymIdx()
+	a.Pcfile = readSymIdx()
+	a.Pcline = readSymIdx()
+	a.Pcinline = readSymIdx()
+	a.Pcdata = make([]SymRef, readUint32())
+	for i := range a.Pcdata {
+		a.Pcdata[i] = readSymIdx()
+	}
+
+	funcdataofflen := readUint32()
+	a.Funcdataoff = make([]uint32, funcdataofflen)
+	for i := range a.Funcdataoff {
+		a.Funcdataoff[i] = readUint32()
+	}
+	filelen := readUint32()
+	a.File = make([]CUFileIndex, filelen)
+	for i := range a.File {
+		a.File[i] = CUFileIndex(readUint32())
+	}
+	inltreelen := readUint32()
+	a.InlTree = make([]InlTreeNode, inltreelen)
+	for i := range a.InlTree {
+		b = a.InlTree[i].Read(b)
+	}
+}
+
+// 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 {
+	NumPcdata      uint32
+	PcdataOff      uint32
+	NumFuncdataoff uint32
+	FuncdataoffOff uint32
+	NumFile        uint32
+	FileOff        uint32
+	NumInlTree     uint32
+	InlTreeOff     uint32
+	Initialized    bool
+}
+
+func (*FuncInfo) ReadFuncInfoLengths(b []byte) FuncInfoLengths {
+	var result FuncInfoLengths
+
+	// Offset to the number of pcdata values. This value is determined by counting
+	// the number of bytes until we write pcdata to the file.
+	const numpcdataOff = 44
+	result.NumPcdata = binary.LittleEndian.Uint32(b[numpcdataOff:])
+	result.PcdataOff = numpcdataOff + 4
+
+	numfuncdataoffOff := result.PcdataOff + 8*result.NumPcdata
+	result.NumFuncdataoff = binary.LittleEndian.Uint32(b[numfuncdataoffOff:])
+	result.FuncdataoffOff = numfuncdataoffOff + 4
+
+	numfileOff := result.FuncdataoffOff + 4*result.NumFuncdataoff
+	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) uint32 { return binary.LittleEndian.Uint32(b[8:]) }
+
+func (*FuncInfo) ReadPcsp(b []byte) SymRef {
+	return SymRef{binary.LittleEndian.Uint32(b[12:]), binary.LittleEndian.Uint32(b[16:])}
+}
+
+func (*FuncInfo) ReadPcfile(b []byte) SymRef {
+	return SymRef{binary.LittleEndian.Uint32(b[20:]), binary.LittleEndian.Uint32(b[24:])}
+}
+
+func (*FuncInfo) ReadPcline(b []byte) SymRef {
+	return SymRef{binary.LittleEndian.Uint32(b[28:]), binary.LittleEndian.Uint32(b[32:])}
+}
+
+func (*FuncInfo) ReadPcinline(b []byte) SymRef {
+	return SymRef{binary.LittleEndian.Uint32(b[36:]), binary.LittleEndian.Uint32(b[40:])}
+}
+
+func (*FuncInfo) ReadPcdata(b []byte) []SymRef {
+	syms := make([]SymRef, binary.LittleEndian.Uint32(b[44:]))
+	for i := range syms {
+		syms[i] = SymRef{binary.LittleEndian.Uint32(b[48+i*8:]), binary.LittleEndian.Uint32(b[52+i*8:])}
+	}
+	return syms
+}
+
+func (*FuncInfo) ReadFuncdataoff(b []byte, funcdataofffoff uint32, k uint32) int64 {
+	return int64(binary.LittleEndian.Uint32(b[funcdataofffoff+4*k:]))
+}
+
+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
+}