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- // 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
- }
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