Adding upstream version 1.21.8.upstream/1.21.8

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 69 insertions, 0 deletions

diff --git a/src/debug/pe/string.go b/src/debug/pe/string.go
new file mode 100644
index 0000000..a156bbe
--- /dev/null
+++ b/src/debug/pe/string.go
@@ -0,0 +1,69 @@
+// 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 pe
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"internal/saferio"
+	"io"
+)
+
+// cstring converts ASCII byte sequence b to string.
+// It stops once it finds 0 or reaches end of b.
+func cstring(b []byte) string {
+	i := bytes.IndexByte(b, 0)
+	if i == -1 {
+		i = len(b)
+	}
+	return string(b[:i])
+}
+
+// StringTable is a COFF string table.
+type StringTable []byte
+
+func readStringTable(fh *FileHeader, r io.ReadSeeker) (StringTable, error) {
+	// COFF string table is located right after COFF symbol table.
+	if fh.PointerToSymbolTable <= 0 {
+		return nil, nil
+	}
+	offset := fh.PointerToSymbolTable + COFFSymbolSize*fh.NumberOfSymbols
+	_, err := r.Seek(int64(offset), seekStart)
+	if err != nil {
+		return nil, fmt.Errorf("fail to seek to string table: %v", err)
+	}
+	var l uint32
+	err = binary.Read(r, binary.LittleEndian, &l)
+	if err != nil {
+		return nil, fmt.Errorf("fail to read string table length: %v", err)
+	}
+	// string table length includes itself
+	if l <= 4 {
+		return nil, nil
+	}
+	l -= 4
+
+	buf, err := saferio.ReadData(r, uint64(l))
+	if err != nil {
+		return nil, fmt.Errorf("fail to read string table: %v", err)
+	}
+	return StringTable(buf), nil
+}
+
+// TODO(brainman): decide if start parameter should be int instead of uint32
+
+// String extracts string from COFF string table st at offset start.
+func (st StringTable) String(start uint32) (string, error) {
+	// start includes 4 bytes of string table length
+	if start < 4 {
+		return "", fmt.Errorf("offset %d is before the start of string table", start)
+	}
+	start -= 4
+	if int(start) > len(st) {
+		return "", fmt.Errorf("offset %d is beyond the end of string table", start)
+	}
+	return cstring(st[start:]), nil
+}