add go mod

pkg/mod/cloud.google.com/go@v0.34.0/cmd/go-cloud-debug-agent/internal/debug/dwarf/typeunit.go

+// Copyright 2018 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package dwarf
+
+import (
+	"fmt"
+	"strconv"
+)
+
+// Parse the type units stored in a DWARF4 .debug_types section.  Each
+// type unit defines a single primary type and an 8-byte signature.
+// Other sections may then use formRefSig8 to refer to the type.
+
+// The typeUnit format is a single type with a signature.  It holds
+// the same data as a compilation unit.
+type typeUnit struct {
+	unit
+	toff  Offset // Offset to signature type within data.
+	name  string // Name of .debug_type section.
+	cache Type   // Cache the type, nil to start.
+}
+
+// Parse a .debug_types section.
+func (d *Data) parseTypes(name string, types []byte) error {
+	b := makeBuf(d, unknownFormat{}, name, 0, types)
+	for len(b.data) > 0 {
+		base := b.off
+		dwarf64 := false
+		n := b.uint32()
+		if n == 0xffffffff {
+			n64 := b.uint64()
+			if n64 != uint64(uint32(n64)) {
+				b.error("type unit length overflow")
+				return b.err
+			}
+			n = uint32(n64)
+			dwarf64 = true
+		}
+		hdroff := b.off
+		vers := b.uint16()
+		if vers != 4 {
+			b.error("unsupported DWARF version " + strconv.Itoa(int(vers)))
+			return b.err
+		}
+		var ao uint32
+		if !dwarf64 {
+			ao = b.uint32()
+		} else {
+			ao64 := b.uint64()
+			if ao64 != uint64(uint32(ao64)) {
+				b.error("type unit abbrev offset overflow")
+				return b.err
+			}
+			ao = uint32(ao64)
+		}
+		atable, err := d.parseAbbrev(ao)
+		if err != nil {
+			return err
+		}
+		asize := b.uint8()
+		sig := b.uint64()
+
+		var toff uint32
+		if !dwarf64 {
+			toff = b.uint32()
+		} else {
+			to64 := b.uint64()
+			if to64 != uint64(uint32(to64)) {
+				b.error("type unit type offset overflow")
+				return b.err
+			}
+			toff = uint32(to64)
+		}
+
+		boff := b.off
+		d.typeSigs[sig] = &typeUnit{
+			unit: unit{
+				base:   base,
+				off:    boff,
+				data:   b.bytes(int(Offset(n) - (b.off - hdroff))),
+				atable: atable,
+				asize:  int(asize),
+				vers:   int(vers),
+				is64:   dwarf64,
+			},
+			toff: Offset(toff),
+			name: name,
+		}
+		if b.err != nil {
+			return b.err
+		}
+	}
+	return nil
+}
+
+// Return the type for a type signature.
+func (d *Data) sigToType(sig uint64) (Type, error) {
+	tu := d.typeSigs[sig]
+	if tu == nil {
+		return nil, fmt.Errorf("no type unit with signature %v", sig)
+	}
+	if tu.cache != nil {
+		return tu.cache, nil
+	}
+
+	b := makeBuf(d, tu, tu.name, tu.off, tu.data)
+	r := &typeUnitReader{d: d, tu: tu, b: b}
+	t, err := d.readType(tu.name, r, Offset(tu.toff), make(map[Offset]Type))
+	if err != nil {
+		return nil, err
+	}
+
+	tu.cache = t
+	return t, nil
+}
+
+// typeUnitReader is a typeReader for a tagTypeUnit.
+type typeUnitReader struct {
+	d   *Data
+	tu  *typeUnit
+	b   buf
+	err error
+}
+
+// Seek to a new position in the type unit.
+func (tur *typeUnitReader) Seek(off Offset) {
+	tur.err = nil
+	doff := off - tur.tu.off
+	if doff < 0 || doff >= Offset(len(tur.tu.data)) {
+		tur.err = fmt.Errorf("%s: offset %d out of range; max %d", tur.tu.name, doff, len(tur.tu.data))
+		return
+	}
+	tur.b = makeBuf(tur.d, tur.tu, tur.tu.name, off, tur.tu.data[doff:])
+}
+
+// AddressSize returns the size in bytes of addresses in the current type unit.
+func (tur *typeUnitReader) AddressSize() int {
+	return tur.tu.unit.asize
+}
+
+// Next reads the next Entry from the type unit.
+func (tur *typeUnitReader) Next() (*Entry, error) {
+	if tur.err != nil {
+		return nil, tur.err
+	}
+	if len(tur.tu.data) == 0 {
+		return nil, nil
+	}
+	e := tur.b.entry(tur.tu.atable, tur.tu.base)
+	if tur.b.err != nil {
+		tur.err = tur.b.err
+		return nil, tur.err
+	}
+	return e, nil
+}
+
+// clone returns a new reader for the type unit.
+func (tur *typeUnitReader) clone() typeReader {
+	return &typeUnitReader{
+		d:  tur.d,
+		tu: tur.tu,
+		b:  makeBuf(tur.d, tur.tu, tur.tu.name, tur.tu.off, tur.tu.data),
+	}
+}
+
+// offset returns the current offset.
+func (tur *typeUnitReader) offset() Offset {
+	return tur.b.off
+}

pkg/mod/cloud.google.com/go@v0.34.0/cmd/go-cloud-debug-agent/internal/debug/dwarf/unit.go

+// Copyright 2018 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package dwarf
+
+import "strconv"
+
+// DWARF debug info is split into a sequence of compilation units.
+// Each unit has its own abbreviation table and address size.
+
+type unit struct {
+	base   Offset // byte offset of header within the aggregate info
+	off    Offset // byte offset of data within the aggregate info
+	data   []byte
+	atable abbrevTable
+	asize  int
+	vers   int
+	is64   bool // True for 64-bit DWARF format
+}
+
+// Implement the dataFormat interface.
+
+func (u *unit) version() int {
+	return u.vers
+}
+
+func (u *unit) dwarf64() (bool, bool) {
+	return u.is64, true
+}
+
+func (u *unit) addrsize() int {
+	return u.asize
+}
+
+func (d *Data) parseUnits() ([]unit, error) {
+	// Count units.
+	nunit := 0
+	b := makeBuf(d, unknownFormat{}, "info", 0, d.info)
+	for len(b.data) > 0 {
+		len := b.uint32()
+		if len == 0xffffffff {
+			len64 := b.uint64()
+			if len64 != uint64(uint32(len64)) {
+				b.error("unit length overflow")
+				break
+			}
+			len = uint32(len64)
+		}
+		b.skip(int(len))
+		nunit++
+	}
+	if b.err != nil {
+		return nil, b.err
+	}
+
+	// Again, this time writing them down.
+	b = makeBuf(d, unknownFormat{}, "info", 0, d.info)
+	units := make([]unit, nunit)
+	for i := range units {
+		u := &units[i]
+		u.base = b.off
+		n := b.uint32()
+		if n == 0xffffffff {
+			u.is64 = true
+			n = uint32(b.uint64())
+		}
+		vers := b.uint16()
+		if vers != 2 && vers != 3 && vers != 4 {
+			b.error("unsupported DWARF version " + strconv.Itoa(int(vers)))
+			break
+		}
+		u.vers = int(vers)
+		atable, err := d.parseAbbrev(b.uint32())
+		if err != nil {
+			if b.err == nil {
+				b.err = err
+			}
+			break
+		}
+		u.atable = atable
+		u.asize = int(b.uint8())
+		u.off = b.off
+		u.data = b.bytes(int(n - (2 + 4 + 1)))
+	}
+	if b.err != nil {
+		return nil, b.err
+	}
+	return units, nil
+}