Turn symbol_inject into a reusable package
Bug: 31559095
Test: m blueprint_tools
Change-Id: I0f7a9f14111af26d753db547c6de313a7079658a
diff --git a/symbol_inject/macho.go b/symbol_inject/macho.go
new file mode 100644
index 0000000..6ee3f4f
--- /dev/null
+++ b/symbol_inject/macho.go
@@ -0,0 +1,97 @@
+// 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 symbol_inject
+
+import (
+ "debug/macho"
+ "fmt"
+ "io"
+ "sort"
+ "strings"
+)
+
+func machoSymbolsFromFile(r io.ReaderAt) (*File, error) {
+ machoFile, err := macho.NewFile(r)
+ if err != nil {
+ return nil, cantParseError{err}
+ }
+
+ return extractMachoSymbols(machoFile)
+}
+
+func extractMachoSymbols(machoFile *macho.File) (*File, error) {
+ symbols := machoFile.Symtab.Syms
+ sort.SliceStable(symbols, func(i, j int) bool {
+ if symbols[i].Sect != symbols[j].Sect {
+ return symbols[i].Sect < symbols[j].Sect
+ }
+ return symbols[i].Value < symbols[j].Value
+ })
+
+ file := &File{}
+
+ for _, section := range machoFile.Sections {
+ file.Sections = append(file.Sections, &Section{
+ Name: section.Name,
+ Addr: section.Addr,
+ Offset: uint64(section.Offset),
+ Size: section.Size,
+ })
+ }
+
+ for _, symbol := range symbols {
+ if symbol.Sect > 0 {
+ section := file.Sections[symbol.Sect-1]
+ file.Symbols = append(file.Symbols, &Symbol{
+ // symbols in macho files seem to be prefixed with an underscore
+ Name: strings.TrimPrefix(symbol.Name, "_"),
+ // MachO symbol value is virtual address of the symbol, convert it to offset into the section.
+ Addr: symbol.Value - section.Addr,
+ // MachO symbols don't have size information.
+ Size: 0,
+ Section: section,
+ })
+ }
+ }
+
+ return file, nil
+}
+
+func dumpMachoSymbols(r io.ReaderAt) error {
+ machoFile, err := macho.NewFile(r)
+ if err != nil {
+ return cantParseError{err}
+ }
+
+ fmt.Println("&macho.File{")
+
+ fmt.Println("\tSections: []*macho.Section{")
+ for _, section := range machoFile.Sections {
+ fmt.Printf("\t\t&macho.Section{SectionHeader: %#v},\n", section.SectionHeader)
+ }
+ fmt.Println("\t},")
+
+ fmt.Println("\tSymtab: &macho.Symtab{")
+ fmt.Println("\t\tSyms: []macho.Symbol{")
+ for _, symbol := range machoFile.Symtab.Syms {
+ fmt.Printf("\t\t\t%#v,\n", symbol)
+ }
+ fmt.Println("\t\t},")
+ fmt.Println("\t},")
+
+ fmt.Println("}")
+
+ return nil
+}