Add gops agentv0.10.2-dev

2 files changed, 1083 insertions, 0 deletions

diff --git a/vendor/github.com/google/gops/internal/dwarf/dwarf.go b/vendor/github.com/google/gops/internal/dwarf/dwarf.go
new file mode 100644
index 00000000..c72ef5b0
--- /dev/null
+++ b/vendor/github.com/google/gops/internal/dwarf/dwarf.go
@@ -0,0 +1,600 @@
+// Copyright 2016 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 dwarf generates DWARF debugging information.
+// DWARF generation is split between the compiler and the linker,
+// this package contains the shared code.
+package dwarf
+
+import (
+	"fmt"
+)
+
+// InfoPrefix is the prefix for all the symbols containing DWARF info entries.
+const InfoPrefix = "go.info."
+
+// Sym represents a symbol.
+type Sym interface {
+}
+
+// A Var represents a local variable or a function parameter.
+type Var struct {
+	Name   string
+	Abbrev int // Either DW_ABRV_AUTO or DW_ABRV_PARAM
+	Offset int32
+	Type   Sym
+	Link   *Var
+}
+
+// A Context specifies how to add data to a Sym.
+type Context interface {
+	PtrSize() int
+	AddInt(s Sym, size int, i int64)
+	AddBytes(s Sym, b []byte)
+	AddAddress(s Sym, t interface{}, ofs int64)
+	AddSectionOffset(s Sym, size int, t interface{}, ofs int64)
+	AddString(s Sym, v string)
+	SymValue(s Sym) int64
+}
+
+// AppendUleb128 appends v to b using DWARF's unsigned LEB128 encoding.
+func AppendUleb128(b []byte, v uint64) []byte {
+	for {
+		c := uint8(v & 0x7f)
+		v >>= 7
+		if v != 0 {
+			c |= 0x80
+		}
+		b = append(b, c)
+		if c&0x80 == 0 {
+			break
+		}
+	}
+	return b
+}
+
+// AppendSleb128 appends v to b using DWARF's signed LEB128 encoding.
+func AppendSleb128(b []byte, v int64) []byte {
+	for {
+		c := uint8(v & 0x7f)
+		s := uint8(v & 0x40)
+		v >>= 7
+		if (v != -1 || s == 0) && (v != 0 || s != 0) {
+			c |= 0x80
+		}
+		b = append(b, c)
+		if c&0x80 == 0 {
+			break
+		}
+	}
+	return b
+}
+
+var encbuf [20]byte
+
+// AppendUleb128 appends v to s using DWARF's unsigned LEB128 encoding.
+func Uleb128put(ctxt Context, s Sym, v int64) {
+	b := AppendUleb128(encbuf[:0], uint64(v))
+	ctxt.AddBytes(s, b)
+}
+
+// AppendUleb128 appends v to s using DWARF's signed LEB128 encoding.
+func Sleb128put(ctxt Context, s Sym, v int64) {
+	b := AppendSleb128(encbuf[:0], v)
+	ctxt.AddBytes(s, b)
+}
+
+/*
+ * Defining Abbrevs.  This is hardcoded, and there will be
+ * only a handful of them.  The DWARF spec places no restriction on
+ * the ordering of attributes in the Abbrevs and DIEs, and we will
+ * always write them out in the order of declaration in the abbrev.
+ */
+type dwAttrForm struct {
+	attr uint16
+	form uint8
+}
+
+// Go-specific type attributes.
+const (
+	DW_AT_go_kind = 0x2900
+	DW_AT_go_key  = 0x2901
+	DW_AT_go_elem = 0x2902
+
+	DW_AT_internal_location = 253 // params and locals; not emitted
+)
+
+// Index into the abbrevs table below.
+// Keep in sync with ispubname() and ispubtype() below.
+// ispubtype considers >= NULLTYPE public
+const (
+	DW_ABRV_NULL = iota
+	DW_ABRV_COMPUNIT
+	DW_ABRV_FUNCTION
+	DW_ABRV_VARIABLE
+	DW_ABRV_AUTO
+	DW_ABRV_PARAM
+	DW_ABRV_STRUCTFIELD
+	DW_ABRV_FUNCTYPEPARAM
+	DW_ABRV_DOTDOTDOT
+	DW_ABRV_ARRAYRANGE
+	DW_ABRV_NULLTYPE
+	DW_ABRV_BASETYPE
+	DW_ABRV_ARRAYTYPE
+	DW_ABRV_CHANTYPE
+	DW_ABRV_FUNCTYPE
+	DW_ABRV_IFACETYPE
+	DW_ABRV_MAPTYPE
+	DW_ABRV_PTRTYPE
+	DW_ABRV_BARE_PTRTYPE // only for void*, no DW_AT_type attr to please gdb 6.
+	DW_ABRV_SLICETYPE
+	DW_ABRV_STRINGTYPE
+	DW_ABRV_STRUCTTYPE
+	DW_ABRV_TYPEDECL
+	DW_NABRV
+)
+
+type dwAbbrev struct {
+	tag      uint8
+	children uint8
+	attr     []dwAttrForm
+}
+
+var abbrevs = [DW_NABRV]dwAbbrev{
+	/* The mandatory DW_ABRV_NULL entry. */
+	{0, 0, []dwAttrForm{}},
+
+	/* COMPUNIT */
+	{
+		DW_TAG_compile_unit,
+		DW_CHILDREN_yes,
+		[]dwAttrForm{
+			{DW_AT_name, DW_FORM_string},
+			{DW_AT_language, DW_FORM_data1},
+			{DW_AT_low_pc, DW_FORM_addr},
+			{DW_AT_high_pc, DW_FORM_addr},
+			{DW_AT_stmt_list, DW_FORM_data4},
+			{DW_AT_comp_dir, DW_FORM_string},
+		},
+	},
+
+	/* FUNCTION */
+	{
+		DW_TAG_subprogram,
+		DW_CHILDREN_yes,
+		[]dwAttrForm{
+			{DW_AT_name, DW_FORM_string},
+			{DW_AT_low_pc, DW_FORM_addr},
+			{DW_AT_high_pc, DW_FORM_addr},
+			{DW_AT_external, DW_FORM_flag},
+		},
+	},
+
+	/* VARIABLE */
+	{
+		DW_TAG_variable,
+		DW_CHILDREN_no,
+		[]dwAttrForm{
+			{DW_AT_name, DW_FORM_string},
+			{DW_AT_location, DW_FORM_block1},
+			{DW_AT_type, DW_FORM_ref_addr},
+			{DW_AT_external, DW_FORM_flag},
+		},
+	},
+
+	/* AUTO */
+	{
+		DW_TAG_variable,
+		DW_CHILDREN_no,
+		[]dwAttrForm{
+			{DW_AT_name, DW_FORM_string},
+			{DW_AT_location, DW_FORM_block1},
+			{DW_AT_type, DW_FORM_ref_addr},
+		},
+	},
+
+	/* PARAM */
+	{
+		DW_TAG_formal_parameter,
+		DW_CHILDREN_no,
+		[]dwAttrForm{
+			{DW_AT_name, DW_FORM_string},
+			{DW_AT_location, DW_FORM_block1},
+			{DW_AT_type, DW_FORM_ref_addr},
+		},
+	},
+
+	/* STRUCTFIELD */
+	{
+		DW_TAG_member,
+		DW_CHILDREN_no,
+		[]dwAttrForm{
+			{DW_AT_name, DW_FORM_string},
+			{DW_AT_data_member_location, DW_FORM_block1},
+			{DW_AT_type, DW_FORM_ref_addr},
+		},
+	},
+
+	/* FUNCTYPEPARAM */
+	{
+		DW_TAG_formal_parameter,
+		DW_CHILDREN_no,
+
+		// No name!
+		[]dwAttrForm{
+			{DW_AT_type, DW_FORM_ref_addr},
+		},
+	},
+
+	/* DOTDOTDOT */
+	{
+		DW_TAG_unspecified_parameters,
+		DW_CHILDREN_no,
+		[]dwAttrForm{},
+	},
+
+	/* ARRAYRANGE */
+	{
+		DW_TAG_subrange_type,
+		DW_CHILDREN_no,
+
+		// No name!
+		[]dwAttrForm{
+			{DW_AT_type, DW_FORM_ref_addr},
+			{DW_AT_count, DW_FORM_udata},
+		},
+	},
+
+	// Below here are the types considered public by ispubtype
+	/* NULLTYPE */
+	{
+		DW_TAG_unspecified_type,
+		DW_CHILDREN_no,
+		[]dwAttrForm{
+			{DW_AT_name, DW_FORM_string},
+		},
+	},
+
+	/* BASETYPE */
+	{
+		DW_TAG_base_type,
+		DW_CHILDREN_no,
+		[]dwAttrForm{
+			{DW_AT_name, DW_FORM_string},
+			{DW_AT_encoding, DW_FORM_data1},
+			{DW_AT_byte_size, DW_FORM_data1},
+			{DW_AT_go_kind, DW_FORM_data1},
+		},
+	},
+
+	/* ARRAYTYPE */
+	// child is subrange with upper bound
+	{
+		DW_TAG_array_type,
+		DW_CHILDREN_yes,
+		[]dwAttrForm{
+			{DW_AT_name, DW_FORM_string},
+			{DW_AT_type, DW_FORM_ref_addr},
+			{DW_AT_byte_size, DW_FORM_udata},
+			{DW_AT_go_kind, DW_FORM_data1},
+		},
+	},
+
+	/* CHANTYPE */
+	{
+		DW_TAG_typedef,
+		DW_CHILDREN_no,
+		[]dwAttrForm{
+			{DW_AT_name, DW_FORM_string},
+			{DW_AT_type, DW_FORM_ref_addr},
+			{DW_AT_go_kind, DW_FORM_data1},
+			{DW_AT_go_elem, DW_FORM_ref_addr},
+		},
+	},
+
+	/* FUNCTYPE */
+	{
+		DW_TAG_subroutine_type,
+		DW_CHILDREN_yes,
+		[]dwAttrForm{
+			{DW_AT_name, DW_FORM_string},
+			// {DW_AT_type,	DW_FORM_ref_addr},
+			{DW_AT_go_kind, DW_FORM_data1},
+		},
+	},
+
+	/* IFACETYPE */
+	{
+		DW_TAG_typedef,
+		DW_CHILDREN_yes,
+		[]dwAttrForm{
+			{DW_AT_name, DW_FORM_string},
+			{DW_AT_type, DW_FORM_ref_addr},
+			{DW_AT_go_kind, DW_FORM_data1},
+		},
+	},
+
+	/* MAPTYPE */
+	{
+		DW_TAG_typedef,
+		DW_CHILDREN_no,
+		[]dwAttrForm{
+			{DW_AT_name, DW_FORM_string},
+			{DW_AT_type, DW_FORM_ref_addr},
+			{DW_AT_go_kind, DW_FORM_data1},
+			{DW_AT_go_key, DW_FORM_ref_addr},
+			{DW_AT_go_elem, DW_FORM_ref_addr},
+		},
+	},
+
+	/* PTRTYPE */
+	{
+		DW_TAG_pointer_type,
+		DW_CHILDREN_no,
+		[]dwAttrForm{
+			{DW_AT_name, DW_FORM_string},
+			{DW_AT_type, DW_FORM_ref_addr},
+			{DW_AT_go_kind, DW_FORM_data1},
+		},
+	},
+
+	/* BARE_PTRTYPE */
+	{
+		DW_TAG_pointer_type,
+		DW_CHILDREN_no,
+		[]dwAttrForm{
+			{DW_AT_name, DW_FORM_string},
+		},
+	},
+
+	/* SLICETYPE */
+	{
+		DW_TAG_structure_type,
+		DW_CHILDREN_yes,
+		[]dwAttrForm{
+			{DW_AT_name, DW_FORM_string},
+			{DW_AT_byte_size, DW_FORM_udata},
+			{DW_AT_go_kind, DW_FORM_data1},
+			{DW_AT_go_elem, DW_FORM_ref_addr},
+		},
+	},
+
+	/* STRINGTYPE */
+	{
+		DW_TAG_structure_type,
+		DW_CHILDREN_yes,
+		[]dwAttrForm{
+			{DW_AT_name, DW_FORM_string},
+			{DW_AT_byte_size, DW_FORM_udata},
+			{DW_AT_go_kind, DW_FORM_data1},
+		},
+	},
+
+	/* STRUCTTYPE */
+	{
+		DW_TAG_structure_type,
+		DW_CHILDREN_yes,
+		[]dwAttrForm{
+			{DW_AT_name, DW_FORM_string},
+			{DW_AT_byte_size, DW_FORM_udata},
+			{DW_AT_go_kind, DW_FORM_data1},
+		},
+	},
+
+	/* TYPEDECL */
+	{
+		DW_TAG_typedef,
+		DW_CHILDREN_no,
+		[]dwAttrForm{
+			{DW_AT_name, DW_FORM_string},
+			{DW_AT_type, DW_FORM_ref_addr},
+		},
+	},
+}
+
+// GetAbbrev returns the contents of the .debug_abbrev section.
+func GetAbbrev() []byte {
+	var buf []byte
+	for i := 1; i < DW_NABRV; i++ {
+		// See section 7.5.3
+		buf = AppendUleb128(buf, uint64(i))
+
+		buf = AppendUleb128(buf, uint64(abbrevs[i].tag))
+		buf = append(buf, byte(abbrevs[i].children))
+		for _, f := range abbrevs[i].attr {
+			buf = AppendUleb128(buf, uint64(f.attr))
+			buf = AppendUleb128(buf, uint64(f.form))
+		}
+		buf = append(buf, 0, 0)
+	}
+	return append(buf, 0)
+}
+
+/*
+ * Debugging Information Entries and their attributes.
+ */
+
+// DWAttr represents an attribute of a DWDie.
+//
+// For DW_CLS_string and _block, value should contain the length, and
+// data the data, for _reference, value is 0 and data is a DWDie* to
+// the referenced instance, for all others, value is the whole thing
+// and data is null.
+type DWAttr struct {
+	Link  *DWAttr
+	Atr   uint16 // DW_AT_
+	Cls   uint8  // DW_CLS_
+	Value int64
+	Data  interface{}
+}
+
+// DWDie represents a DWARF debug info entry.
+type DWDie struct {
+	Abbrev int
+	Link   *DWDie
+	Child  *DWDie
+	Attr   *DWAttr
+	Sym    Sym
+}
+
+func putattr(ctxt Context, s Sym, abbrev int, form int, cls int, value int64, data interface{}) error {
+	switch form {
+	case DW_FORM_addr: // address
+		ctxt.AddAddress(s, data, value)
+
+	case DW_FORM_block1: // block
+		if cls == DW_CLS_ADDRESS {
+			ctxt.AddInt(s, 1, int64(1+ctxt.PtrSize()))
+			ctxt.AddInt(s, 1, DW_OP_addr)
+			ctxt.AddAddress(s, data, 0)
+			break
+		}
+
+		value &= 0xff
+		ctxt.AddInt(s, 1, value)
+		p := data.([]byte)[:value]
+		ctxt.AddBytes(s, p)
+
+	case DW_FORM_block2: // block
+		value &= 0xffff
+
+		ctxt.AddInt(s, 2, value)
+		p := data.([]byte)[:value]
+		ctxt.AddBytes(s, p)
+
+	case DW_FORM_block4: // block
+		value &= 0xffffffff
+
+		ctxt.AddInt(s, 4, value)
+		p := data.([]byte)[:value]
+		ctxt.AddBytes(s, p)
+
+	case DW_FORM_block: // block
+		Uleb128put(ctxt, s, value)
+
+		p := data.([]byte)[:value]
+		ctxt.AddBytes(s, p)
+
+	case DW_FORM_data1: // constant
+		ctxt.AddInt(s, 1, value)
+
+	case DW_FORM_data2: // constant
+		ctxt.AddInt(s, 2, value)
+
+	case DW_FORM_data4: // constant, {line,loclist,mac,rangelist}ptr
+		if cls == DW_CLS_PTR { // DW_AT_stmt_list
+			ctxt.AddSectionOffset(s, 4, data, 0)
+			break
+		}
+		ctxt.AddInt(s, 4, value)
+
+	case DW_FORM_data8: // constant, {line,loclist,mac,rangelist}ptr
+		ctxt.AddInt(s, 8, value)
+
+	case DW_FORM_sdata: // constant
+		Sleb128put(ctxt, s, value)
+
+	case DW_FORM_udata: // constant
+		Uleb128put(ctxt, s, value)
+
+	case DW_FORM_string: // string
+		str := data.(string)
+		ctxt.AddString(s, str)
+		// TODO(ribrdb): verify padded strings are never used and remove this
+		for i := int64(len(str)); i < value; i++ {
+			ctxt.AddInt(s, 1, 0)
+		}
+
+	case DW_FORM_flag: // flag
+		if value != 0 {
+			ctxt.AddInt(s, 1, 1)
+		} else {
+			ctxt.AddInt(s, 1, 0)
+		}
+
+	// In DWARF 2 (which is what we claim to generate),
+	// the ref_addr is the same size as a normal address.
+	// In DWARF 3 it is always 32 bits, unless emitting a large
+	// (> 4 GB of debug info aka "64-bit") unit, which we don't implement.
+	case DW_FORM_ref_addr: // reference to a DIE in the .info section
+		if data == nil {
+			return fmt.Errorf("dwarf: null reference in %d", abbrev)
+		} else {
+			ctxt.AddSectionOffset(s, ctxt.PtrSize(), data, 0)
+		}
+
+	case DW_FORM_ref1, // reference within the compilation unit
+		DW_FORM_ref2,      // reference
+		DW_FORM_ref4,      // reference
+		DW_FORM_ref8,      // reference
+		DW_FORM_ref_udata, // reference
+
+		DW_FORM_strp,     // string
+		DW_FORM_indirect: // (see Section 7.5.3)
+		fallthrough
+	default:
+		return fmt.Errorf("dwarf: unsupported attribute form %d / class %d", form, cls)
+	}
+	return nil
+}
+
+// PutAttrs writes the attributes for a DIE to symbol 's'.
+//
+// Note that we can (and do) add arbitrary attributes to a DIE, but
+// only the ones actually listed in the Abbrev will be written out.
+func PutAttrs(ctxt Context, s Sym, abbrev int, attr *DWAttr) {
+Outer:
+	for _, f := range abbrevs[abbrev].attr {
+		for ap := attr; ap != nil; ap = ap.Link {
+			if ap.Atr == f.attr {
+				putattr(ctxt, s, abbrev, int(f.form), int(ap.Cls), ap.Value, ap.Data)
+				continue Outer
+			}
+		}
+
+		putattr(ctxt, s, abbrev, int(f.form), 0, 0, nil)
+	}
+}
+
+// HasChildren returns true if 'die' uses an abbrev that supports children.
+func HasChildren(die *DWDie) bool {
+	return abbrevs[die.Abbrev].children != 0
+}
+
+// PutFunc writes a DIE for a function to s.
+// It also writes child DIEs for each variable in vars.
+func PutFunc(ctxt Context, s Sym, name string, external bool, startPC Sym, size int64, vars *Var) {
+	Uleb128put(ctxt, s, DW_ABRV_FUNCTION)
+	putattr(ctxt, s, DW_ABRV_FUNCTION, DW_FORM_string, DW_CLS_STRING, int64(len(name)), name)
+	putattr(ctxt, s, DW_ABRV_FUNCTION, DW_FORM_addr, DW_CLS_ADDRESS, 0, startPC)
+	putattr(ctxt, s, DW_ABRV_FUNCTION, DW_FORM_addr, DW_CLS_ADDRESS, size+ctxt.SymValue(startPC), startPC)
+	var ev int64
+	if external {
+		ev = 1
+	}
+	putattr(ctxt, s, DW_ABRV_FUNCTION, DW_FORM_flag, DW_CLS_FLAG, ev, 0)
+	names := make(map[string]bool)
+	for v := vars; v != nil; v = v.Link {
+		var n string
+		if names[v.Name] {
+			n = fmt.Sprintf("%s#%d", v.Name, len(names))
+		} else {
+			n = v.Name
+		}
+		names[n] = true
+
+		Uleb128put(ctxt, s, int64(v.Abbrev))
+		putattr(ctxt, s, v.Abbrev, DW_FORM_string, DW_CLS_STRING, int64(len(n)), n)
+		loc := append(encbuf[:0], DW_OP_call_frame_cfa)
+		if v.Offset != 0 {
+			loc = append(loc, DW_OP_consts)
+			loc = AppendSleb128(loc, int64(v.Offset))
+			loc = append(loc, DW_OP_plus)
+		}
+		putattr(ctxt, s, v.Abbrev, DW_FORM_block1, DW_CLS_BLOCK, int64(len(loc)), loc)
+		putattr(ctxt, s, v.Abbrev, DW_FORM_ref_addr, DW_CLS_REFERENCE, 0, v.Type)
+
+	}
+	Uleb128put(ctxt, s, 0)
+}
diff --git a/vendor/github.com/google/gops/internal/dwarf/dwarf_defs.go b/vendor/github.com/google/gops/internal/dwarf/dwarf_defs.go
new file mode 100644
index 00000000..d1870b57
--- /dev/null
+++ b/vendor/github.com/google/gops/internal/dwarf/dwarf_defs.go
@@ -0,0 +1,483 @@
+// Copyright 2010 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 dwarf
+
+// Cut, pasted, tr-and-awk'ed from tables in
+// http://dwarfstd.org/doc/Dwarf3.pdf
+
+// Table 18
+const (
+	DW_TAG_array_type               = 0x01
+	DW_TAG_class_type               = 0x02
+	DW_TAG_entry_point              = 0x03
+	DW_TAG_enumeration_type         = 0x04
+	DW_TAG_formal_parameter         = 0x05
+	DW_TAG_imported_declaration     = 0x08
+	DW_TAG_label                    = 0x0a
+	DW_TAG_lexical_block            = 0x0b
+	DW_TAG_member                   = 0x0d
+	DW_TAG_pointer_type             = 0x0f
+	DW_TAG_reference_type           = 0x10
+	DW_TAG_compile_unit             = 0x11
+	DW_TAG_string_type              = 0x12
+	DW_TAG_structure_type           = 0x13
+	DW_TAG_subroutine_type          = 0x15
+	DW_TAG_typedef                  = 0x16
+	DW_TAG_union_type               = 0x17
+	DW_TAG_unspecified_parameters   = 0x18
+	DW_TAG_variant                  = 0x19
+	DW_TAG_common_block             = 0x1a
+	DW_TAG_common_inclusion         = 0x1b
+	DW_TAG_inheritance              = 0x1c
+	DW_TAG_inlined_subroutine       = 0x1d
+	DW_TAG_module                   = 0x1e
+	DW_TAG_ptr_to_member_type       = 0x1f
+	DW_TAG_set_type                 = 0x20
+	DW_TAG_subrange_type            = 0x21
+	DW_TAG_with_stmt                = 0x22
+	DW_TAG_access_declaration       = 0x23
+	DW_TAG_base_type                = 0x24
+	DW_TAG_catch_block              = 0x25
+	DW_TAG_const_type               = 0x26
+	DW_TAG_constant                 = 0x27
+	DW_TAG_enumerator               = 0x28
+	DW_TAG_file_type                = 0x29
+	DW_TAG_friend                   = 0x2a
+	DW_TAG_namelist                 = 0x2b
+	DW_TAG_namelist_item            = 0x2c
+	DW_TAG_packed_type              = 0x2d
+	DW_TAG_subprogram               = 0x2e
+	DW_TAG_template_type_parameter  = 0x2f
+	DW_TAG_template_value_parameter = 0x30
+	DW_TAG_thrown_type              = 0x31
+	DW_TAG_try_block                = 0x32
+	DW_TAG_variant_part             = 0x33
+	DW_TAG_variable                 = 0x34
+	DW_TAG_volatile_type            = 0x35
+	// Dwarf3
+	DW_TAG_dwarf_procedure  = 0x36
+	DW_TAG_restrict_type    = 0x37
+	DW_TAG_interface_type   = 0x38
+	DW_TAG_namespace        = 0x39
+	DW_TAG_imported_module  = 0x3a
+	DW_TAG_unspecified_type = 0x3b
+	DW_TAG_partial_unit     = 0x3c
+	DW_TAG_imported_unit    = 0x3d
+	DW_TAG_condition        = 0x3f
+	DW_TAG_shared_type      = 0x40
+	// Dwarf4
+	DW_TAG_type_unit             = 0x41
+	DW_TAG_rvalue_reference_type = 0x42
+	DW_TAG_template_alias        = 0x43
+
+	// User defined
+	DW_TAG_lo_user = 0x4080
+	DW_TAG_hi_user = 0xffff
+)
+
+// Table 19
+const (
+	DW_CHILDREN_no  = 0x00
+	DW_CHILDREN_yes = 0x01
+)
+
+// Not from the spec, but logically belongs here
+const (
+	DW_CLS_ADDRESS = 0x01 + iota
+	DW_CLS_BLOCK
+	DW_CLS_CONSTANT
+	DW_CLS_FLAG
+	DW_CLS_PTR // lineptr, loclistptr, macptr, rangelistptr
+	DW_CLS_REFERENCE
+	DW_CLS_ADDRLOC
+	DW_CLS_STRING
+)
+
+// Table 20
+const (
+	DW_AT_sibling              = 0x01 // reference
+	DW_AT_location             = 0x02 // block, loclistptr
+	DW_AT_name                 = 0x03 // string
+	DW_AT_ordering             = 0x09 // constant
+	DW_AT_byte_size            = 0x0b // block, constant, reference
+	DW_AT_bit_offset           = 0x0c // block, constant, reference
+	DW_AT_bit_size             = 0x0d // block, constant, reference
+	DW_AT_stmt_list            = 0x10 // lineptr
+	DW_AT_low_pc               = 0x11 // address
+	DW_AT_high_pc              = 0x12 // address
+	DW_AT_language             = 0x13 // constant
+	DW_AT_discr                = 0x15 // reference
+	DW_AT_discr_value          = 0x16 // constant
+	DW_AT_visibility           = 0x17 // constant
+	DW_AT_import               = 0x18 // reference
+	DW_AT_string_length        = 0x19 // block, loclistptr
+	DW_AT_common_reference     = 0x1a // reference
+	DW_AT_comp_dir             = 0x1b // string
+	DW_AT_const_value          = 0x1c // block, constant, string
+	DW_AT_containing_type      = 0x1d // reference
+	DW_AT_default_value        = 0x1e // reference
+	DW_AT_inline               = 0x20 // constant
+	DW_AT_is_optional          = 0x21 // flag
+	DW_AT_lower_bound          = 0x22 // block, constant, reference
+	DW_AT_producer             = 0x25 // string
+	DW_AT_prototyped           = 0x27 // flag
+	DW_AT_return_addr          = 0x2a // block, loclistptr
+	DW_AT_start_scope          = 0x2c // constant
+	DW_AT_bit_stride           = 0x2e // constant
+	DW_AT_upper_bound          = 0x2f // block, constant, reference
+	DW_AT_abstract_origin      = 0x31 // reference
+	DW_AT_accessibility        = 0x32 // constant
+	DW_AT_address_class        = 0x33 // constant
+	DW_AT_artificial           = 0x34 // flag
+	DW_AT_base_types           = 0x35 // reference
+	DW_AT_calling_convention   = 0x36 // constant
+	DW_AT_count                = 0x37 // block, constant, reference
+	DW_AT_data_member_location = 0x38 // block, constant, loclistptr
+	DW_AT_decl_column          = 0x39 // constant
+	DW_AT_decl_file            = 0x3a // constant
+	DW_AT_decl_line            = 0x3b // constant
+	DW_AT_declaration          = 0x3c // flag
+	DW_AT_discr_list           = 0x3d // block
+	DW_AT_encoding             = 0x3e // constant
+	DW_AT_external             = 0x3f // flag
+	DW_AT_frame_base           = 0x40 // block, loclistptr
+	DW_AT_friend               = 0x41 // reference
+	DW_AT_identifier_case      = 0x42 // constant
+	DW_AT_macro_info           = 0x43 // macptr
+	DW_AT_namelist_item        = 0x44 // block
+	DW_AT_priority             = 0x45 // reference
+	DW_AT_segment              = 0x46 // block, loclistptr
+	DW_AT_specification        = 0x47 // reference
+	DW_AT_static_link          = 0x48 // block, loclistptr
+	DW_AT_type                 = 0x49 // reference
+	DW_AT_use_location         = 0x4a // block, loclistptr
+	DW_AT_variable_parameter   = 0x4b // flag
+	DW_AT_virtuality           = 0x4c // constant
+	DW_AT_vtable_elem_location = 0x4d // block, loclistptr
+	// Dwarf3
+	DW_AT_allocated      = 0x4e // block, constant, reference
+	DW_AT_associated     = 0x4f // block, constant, reference
+	DW_AT_data_location  = 0x50 // block
+	DW_AT_byte_stride    = 0x51 // block, constant, reference
+	DW_AT_entry_pc       = 0x52 // address
+	DW_AT_use_UTF8       = 0x53 // flag
+	DW_AT_extension      = 0x54 // reference
+	DW_AT_ranges         = 0x55 // rangelistptr
+	DW_AT_trampoline     = 0x56 // address, flag, reference, string
+	DW_AT_call_column    = 0x57 // constant
+	DW_AT_call_file      = 0x58 // constant
+	DW_AT_call_line      = 0x59 // constant
+	DW_AT_description    = 0x5a // string
+	DW_AT_binary_scale   = 0x5b // constant
+	DW_AT_decimal_scale  = 0x5c // constant
+	DW_AT_small          = 0x5d // reference
+	DW_AT_decimal_sign   = 0x5e // constant
+	DW_AT_digit_count    = 0x5f // constant
+	DW_AT_picture_string = 0x60 // string
+	DW_AT_mutable        = 0x61 // flag
+	DW_AT_threads_scaled = 0x62 // flag
+	DW_AT_explicit       = 0x63 // flag
+	DW_AT_object_pointer = 0x64 // reference
+	DW_AT_endianity      = 0x65 // constant
+	DW_AT_elemental      = 0x66 // flag
+	DW_AT_pure           = 0x67 // flag
+	DW_AT_recursive      = 0x68 // flag
+
+	DW_AT_lo_user = 0x2000 // ---
+	DW_AT_hi_user = 0x3fff // ---
+)
+
+// Table 21
+const (
+	DW_FORM_addr      = 0x01 // address
+	DW_FORM_block2    = 0x03 // block
+	DW_FORM_block4    = 0x04 // block
+	DW_FORM_data2     = 0x05 // constant
+	DW_FORM_data4     = 0x06 // constant, lineptr, loclistptr, macptr, rangelistptr
+	DW_FORM_data8     = 0x07 // constant, lineptr, loclistptr, macptr, rangelistptr
+	DW_FORM_string    = 0x08 // string
+	DW_FORM_block     = 0x09 // block
+	DW_FORM_block1    = 0x0a // block
+	DW_FORM_data1     = 0x0b // constant
+	DW_FORM_flag      = 0x0c // flag
+	DW_FORM_sdata     = 0x0d // constant
+	DW_FORM_strp      = 0x0e // string
+	DW_FORM_udata     = 0x0f // constant
+	DW_FORM_ref_addr  = 0x10 // reference
+	DW_FORM_ref1      = 0x11 // reference
+	DW_FORM_ref2      = 0x12 // reference
+	DW_FORM_ref4      = 0x13 // reference
+	DW_FORM_ref8      = 0x14 // reference
+	DW_FORM_ref_udata = 0x15 // reference
+	DW_FORM_indirect  = 0x16 // (see Section 7.5.3)
+)
+
+// Table 24 (#operands, notes)
+const (
+	DW_OP_addr                = 0x03 // 1 constant address (size target specific)
+	DW_OP_deref               = 0x06 // 0
+	DW_OP_const1u             = 0x08 // 1 1-byte constant
+	DW_OP_const1s             = 0x09 // 1 1-byte constant
+	DW_OP_const2u             = 0x0a // 1 2-byte constant
+	DW_OP_const2s             = 0x0b // 1 2-byte constant
+	DW_OP_const4u             = 0x0c // 1 4-byte constant
+	DW_OP_const4s             = 0x0d // 1 4-byte constant
+	DW_OP_const8u             = 0x0e // 1 8-byte constant
+	DW_OP_const8s             = 0x0f // 1 8-byte constant
+	DW_OP_constu              = 0x10 // 1 ULEB128 constant
+	DW_OP_consts              = 0x11 // 1 SLEB128 constant
+	DW_OP_dup                 = 0x12 // 0
+	DW_OP_drop                = 0x13 // 0
+	DW_OP_over                = 0x14 // 0
+	DW_OP_pick                = 0x15 // 1 1-byte stack index
+	DW_OP_swap                = 0x16 // 0
+	DW_OP_rot                 = 0x17 // 0
+	DW_OP_xderef              = 0x18 // 0
+	DW_OP_abs                 = 0x19 // 0
+	DW_OP_and                 = 0x1a // 0
+	DW_OP_div                 = 0x1b // 0
+	DW_OP_minus               = 0x1c // 0
+	DW_OP_mod                 = 0x1d // 0
+	DW_OP_mul                 = 0x1e // 0
+	DW_OP_neg                 = 0x1f // 0
+	DW_OP_not                 = 0x20 // 0
+	DW_OP_or                  = 0x21 // 0
+	DW_OP_plus                = 0x22 // 0
+	DW_OP_plus_uconst         = 0x23 // 1 ULEB128 addend
+	DW_OP_shl                 = 0x24 // 0
+	DW_OP_shr                 = 0x25 // 0
+	DW_OP_shra                = 0x26 // 0
+	DW_OP_xor                 = 0x27 // 0
+	DW_OP_skip                = 0x2f // 1 signed 2-byte constant
+	DW_OP_bra                 = 0x28 // 1 signed 2-byte constant
+	DW_OP_eq                  = 0x29 // 0
+	DW_OP_ge                  = 0x2a // 0
+	DW_OP_gt                  = 0x2b // 0
+	DW_OP_le                  = 0x2c // 0
+	DW_OP_lt                  = 0x2d // 0
+	DW_OP_ne                  = 0x2e // 0
+	DW_OP_lit0                = 0x30 // 0 ...
+	DW_OP_lit31               = 0x4f // 0 literals 0..31 = (DW_OP_lit0 + literal)
+	DW_OP_reg0                = 0x50 // 0 ..
+	DW_OP_reg31               = 0x6f // 0 reg 0..31 = (DW_OP_reg0 + regnum)
+	DW_OP_breg0               = 0x70 // 1 ...
+	DW_OP_breg31              = 0x8f // 1 SLEB128 offset base register 0..31 = (DW_OP_breg0 + regnum)
+	DW_OP_regx                = 0x90 // 1 ULEB128 register
+	DW_OP_fbreg               = 0x91 // 1 SLEB128 offset
+	DW_OP_bregx               = 0x92 // 2 ULEB128 register followed by SLEB128 offset
+	DW_OP_piece               = 0x93 // 1 ULEB128 size of piece addressed
+	DW_OP_deref_size          = 0x94 // 1 1-byte size of data retrieved
+	DW_OP_xderef_size         = 0x95 // 1 1-byte size of data retrieved
+	DW_OP_nop                 = 0x96 // 0
+	DW_OP_push_object_address = 0x97 // 0
+	DW_OP_call2               = 0x98 // 1 2-byte offset of DIE
+	DW_OP_call4               = 0x99 // 1 4-byte offset of DIE
+	DW_OP_call_ref            = 0x9a // 1 4- or 8-byte offset of DIE
+	DW_OP_form_tls_address    = 0x9b // 0
+	DW_OP_call_frame_cfa      = 0x9c // 0
+	DW_OP_bit_piece           = 0x9d // 2
+	DW_OP_lo_user             = 0xe0
+	DW_OP_hi_user             = 0xff
+)
+
+// Table 25
+const (
+	DW_ATE_address         = 0x01
+	DW_ATE_boolean         = 0x02
+	DW_ATE_complex_float   = 0x03
+	DW_ATE_float           = 0x04
+	DW_ATE_signed          = 0x05
+	DW_ATE_signed_char     = 0x06
+	DW_ATE_unsigned        = 0x07
+	DW_ATE_unsigned_char   = 0x08
+	DW_ATE_imaginary_float = 0x09
+	DW_ATE_packed_decimal  = 0x0a
+	DW_ATE_numeric_string  = 0x0b
+	DW_ATE_edited          = 0x0c
+	DW_ATE_signed_fixed    = 0x0d
+	DW_ATE_unsigned_fixed  = 0x0e
+	DW_ATE_decimal_float   = 0x0f
+	DW_ATE_lo_user         = 0x80
+	DW_ATE_hi_user         = 0xff
+)
+
+// Table 26
+const (
+	DW_DS_unsigned           = 0x01
+	DW_DS_leading_overpunch  = 0x02
+	DW_DS_trailing_overpunch = 0x03
+	DW_DS_leading_separate   = 0x04
+	DW_DS_trailing_separate  = 0x05
+)
+
+// Table 27
+const (
+	DW_END_default = 0x00
+	DW_END_big     = 0x01
+	DW_END_little  = 0x02
+	DW_END_lo_user = 0x40
+	DW_END_hi_user = 0xff
+)
+
+// Table 28
+const (
+	DW_ACCESS_public    = 0x01
+	DW_ACCESS_protected = 0x02
+	DW_ACCESS_private   = 0x03
+)
+
+// Table 29
+const (
+	DW_VIS_local     = 0x01
+	DW_VIS_exported  = 0x02
+	DW_VIS_qualified = 0x03
+)
+
+// Table 30
+const (
+	DW_VIRTUALITY_none         = 0x00
+	DW_VIRTUALITY_virtual      = 0x01
+	DW_VIRTUALITY_pure_virtual = 0x02
+)
+
+// Table 31
+const (
+	DW_LANG_C89         = 0x0001
+	DW_LANG_C           = 0x0002
+	DW_LANG_Ada83       = 0x0003
+	DW_LANG_C_plus_plus = 0x0004
+	DW_LANG_Cobol74     = 0x0005
+	DW_LANG_Cobol85     = 0x0006
+	DW_LANG_Fortran77   = 0x0007
+	DW_LANG_Fortran90   = 0x0008
+	DW_LANG_Pascal83    = 0x0009
+	DW_LANG_Modula2     = 0x000a
+	// Dwarf3
+	DW_LANG_Java           = 0x000b
+	DW_LANG_C99            = 0x000c
+	DW_LANG_Ada95          = 0x000d
+	DW_LANG_Fortran95      = 0x000e
+	DW_LANG_PLI            = 0x000f
+	DW_LANG_ObjC           = 0x0010
+	DW_LANG_ObjC_plus_plus = 0x0011
+	DW_LANG_UPC            = 0x0012
+	DW_LANG_D              = 0x0013
+	// Dwarf4
+	DW_LANG_Python = 0x0014
+	// Dwarf5
+	DW_LANG_Go = 0x0016
+
+	DW_LANG_lo_user = 0x8000
+	DW_LANG_hi_user = 0xffff
+)
+
+// Table 32
+const (
+	DW_ID_case_sensitive   = 0x00
+	DW_ID_up_case          = 0x01
+	DW_ID_down_case        = 0x02
+	DW_ID_case_insensitive = 0x03
+)
+
+// Table 33
+const (
+	DW_CC_normal  = 0x01
+	DW_CC_program = 0x02
+	DW_CC_nocall  = 0x03
+	DW_CC_lo_user = 0x40
+	DW_CC_hi_user = 0xff
+)
+
+// Table 34
+const (
+	DW_INL_not_inlined          = 0x00
+	DW_INL_inlined              = 0x01
+	DW_INL_declared_not_inlined = 0x02
+	DW_INL_declared_inlined     = 0x03
+)
+
+// Table 35
+const (
+	DW_ORD_row_major = 0x00
+	DW_ORD_col_major = 0x01
+)
+
+// Table 36
+const (
+	DW_DSC_label = 0x00
+	DW_DSC_range = 0x01
+)
+
+// Table 37
+const (
+	DW_LNS_copy             = 0x01
+	DW_LNS_advance_pc       = 0x02
+	DW_LNS_advance_line     = 0x03
+	DW_LNS_set_file         = 0x04
+	DW_LNS_set_column       = 0x05
+	DW_LNS_negate_stmt      = 0x06
+	DW_LNS_set_basic_block  = 0x07
+	DW_LNS_const_add_pc     = 0x08
+	DW_LNS_fixed_advance_pc = 0x09
+	// Dwarf3
+	DW_LNS_set_prologue_end   = 0x0a
+	DW_LNS_set_epilogue_begin = 0x0b
+	DW_LNS_set_isa            = 0x0c
+)
+
+// Table 38
+const (
+	DW_LNE_end_sequence = 0x01
+	DW_LNE_set_address  = 0x02
+	DW_LNE_define_file  = 0x03
+	DW_LNE_lo_user      = 0x80
+	DW_LNE_hi_user      = 0xff
+)
+
+// Table 39
+const (
+	DW_MACINFO_define     = 0x01
+	DW_MACINFO_undef      = 0x02
+	DW_MACINFO_start_file = 0x03
+	DW_MACINFO_end_file   = 0x04
+	DW_MACINFO_vendor_ext = 0xff
+)
+
+// Table 40.
+const (
+	// operand,...
+	DW_CFA_nop              = 0x00
+	DW_CFA_set_loc          = 0x01 // address
+	DW_CFA_advance_loc1     = 0x02 // 1-byte delta
+	DW_CFA_advance_loc2     = 0x03 // 2-byte delta
+	DW_CFA_advance_loc4     = 0x04 // 4-byte delta
+	DW_CFA_offset_extended  = 0x05 // ULEB128 register, ULEB128 offset
+	DW_CFA_restore_extended = 0x06 // ULEB128 register
+	DW_CFA_undefined        = 0x07 // ULEB128 register
+	DW_CFA_same_value       = 0x08 // ULEB128 register
+	DW_CFA_register         = 0x09 // ULEB128 register, ULEB128 register
+	DW_CFA_remember_state   = 0x0a
+	DW_CFA_restore_state    = 0x0b
+
+	DW_CFA_def_cfa            = 0x0c // ULEB128 register, ULEB128 offset
+	DW_CFA_def_cfa_register   = 0x0d // ULEB128 register
+	DW_CFA_def_cfa_offset     = 0x0e // ULEB128 offset
+	DW_CFA_def_cfa_expression = 0x0f // BLOCK
+	DW_CFA_expression         = 0x10 // ULEB128 register, BLOCK
+	DW_CFA_offset_extended_sf = 0x11 // ULEB128 register, SLEB128 offset
+	DW_CFA_def_cfa_sf         = 0x12 // ULEB128 register, SLEB128 offset
+	DW_CFA_def_cfa_offset_sf  = 0x13 // SLEB128 offset
+	DW_CFA_val_offset         = 0x14 // ULEB128, ULEB128
+	DW_CFA_val_offset_sf      = 0x15 // ULEB128, SLEB128
+	DW_CFA_val_expression     = 0x16 // ULEB128, BLOCK
+
+	DW_CFA_lo_user = 0x1c
+	DW_CFA_hi_user = 0x3f
+
+	// Opcodes that take an addend operand.
+	DW_CFA_advance_loc = 0x1 << 6 // +delta
+	DW_CFA_offset      = 0x2 << 6 // +register (ULEB128 offset)
+	DW_CFA_restore     = 0x3 << 6 // +register
+)