Turn symbol_inject into a reusable package

Bug: 31559095
Test: m blueprint_tools
Change-Id: I0f7a9f14111af26d753db547c6de313a7079658a

1 files changed, 102 insertions, 0 deletions

diff --git a/symbol_inject/pe.go b/symbol_inject/pe.go
new file mode 100644
index 000000000..58cf91a5a
--- /dev/null
+++ b/symbol_inject/pe.go
@@ -0,0 +1,102 @@
+// 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/pe"
+	"fmt"
+	"io"
+	"sort"
+	"strings"
+)
+
+func peSymbolsFromFile(r io.ReaderAt) (*File, error) {
+	peFile, err := pe.NewFile(r)
+	if err != nil {
+		return nil, cantParseError{err}
+	}
+
+	return extractPESymbols(peFile)
+}
+
+func extractPESymbols(peFile *pe.File) (*File, error) {
+	var prefix string
+	if peFile.FileHeader.Machine == pe.IMAGE_FILE_MACHINE_I386 {
+		// symbols in win32 exes seem to be prefixed with an underscore
+		prefix = "_"
+	}
+
+	symbols := peFile.Symbols
+	sort.SliceStable(symbols, func(i, j int) bool {
+		if symbols[i].SectionNumber != symbols[j].SectionNumber {
+			return symbols[i].SectionNumber < symbols[j].SectionNumber
+		}
+		return symbols[i].Value < symbols[j].Value
+	})
+
+	file := &File{}
+
+	for _, section := range peFile.Sections {
+		file.Sections = append(file.Sections, &Section{
+			Name:   section.Name,
+			Addr:   uint64(section.VirtualAddress),
+			Offset: uint64(section.Offset),
+			Size:   uint64(section.VirtualSize),
+		})
+	}
+
+	for _, symbol := range symbols {
+		if symbol.SectionNumber > 0 {
+			file.Symbols = append(file.Symbols, &Symbol{
+				Name: strings.TrimPrefix(symbol.Name, prefix),
+				// PE symbol value is the offset of the symbol into the section
+				Addr: uint64(symbol.Value),
+				// PE symbols don't have size information
+				Size:    0,
+				Section: file.Sections[symbol.SectionNumber-1],
+			})
+		}
+	}
+
+	return file, nil
+}
+
+func dumpPESymbols(r io.ReaderAt) error {
+	peFile, err := pe.NewFile(r)
+	if err != nil {
+		return cantParseError{err}
+	}
+
+	fmt.Println("&pe.File{")
+	fmt.Println("\tFileHeader: pe.FileHeader{")
+	fmt.Printf("\t\tMachine: %#v,\n", peFile.FileHeader.Machine)
+	fmt.Println("\t},")
+
+	fmt.Println("\tSections: []*pe.Section{")
+	for _, section := range peFile.Sections {
+		fmt.Printf("\t\t&pe.Section{SectionHeader: %#v},\n", section.SectionHeader)
+	}
+	fmt.Println("\t},")
+
+	fmt.Println("\tSymbols: []*pe.Symbol{")
+	for _, symbol := range peFile.Symbols {
+		fmt.Printf("\t\t%#v,\n", symbol)
+	}
+	fmt.Println("\t},")
+
+	fmt.Println("}")
+
+	return nil
+}