convert to go buildpack

71 files changed, 46317 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 0000000..c72ef5b
--- /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_ref