1 files changed, 135 insertions, 0 deletions
diff --git a/src/cmd/oldlink/internal/sym/symbols.go b/src/cmd/oldlink/internal/sym/symbols.go
new file mode 100644
index 0000000000..e772496534
--- /dev/null
+++ b/src/cmd/oldlink/internal/sym/symbols.go
@@ -0,0 +1,135 @@
+// Derived from Inferno utils/6l/l.h and related files.
+// https://bitbucket.org/inferno-os/inferno-os/src/default/utils/6l/l.h
+//
+//	Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
+//	Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
+//	Portions Copyright © 1997-1999 Vita Nuova Limited
+//	Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
+//	Portions Copyright © 2004,2006 Bruce Ellis
+//	Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
+//	Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
+//	Portions Copyright © 2009 The Go Authors. All rights reserved.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package sym
+
+type Symbols struct {
+	symbolBatch []Symbol
+
+	// Symbol lookup based on name and indexed by version.
+	hash []map[string]*Symbol
+
+	Allsym []*Symbol
+}
+
+func NewSymbols() *Symbols {
+	hash := make([]map[string]*Symbol, SymVerStatic)
+	// Preallocate about 2mb for hash of non static symbols
+	hash[0] = make(map[string]*Symbol, 100000)
+	// And another 1mb for internal ABI text symbols.
+	hash[SymVerABIInternal] = make(map[string]*Symbol, 50000)
+	return &Symbols{
+		hash:   hash,
+		Allsym: make([]*Symbol, 0, 100000),
+	}
+}
+
+func (syms *Symbols) Newsym(name string, v int) *Symbol {
+	batch := syms.symbolBatch
+	if len(batch) == 0 {
+		batch = make([]Symbol, 1000)
+	}
+	s := &batch[0]
+	syms.symbolBatch = batch[1:]
+
+	s.Dynid = -1
+	s.Name = name
+	s.Version = int16(v)
+	syms.Allsym = append(syms.Allsym, s)
+
+	return s
+}
+
+// Look up the symbol with the given name and version, creating the
+// symbol if it is not found.
+func (syms *Symbols) Lookup(name string, v int) *Symbol {
+	m := syms.hash[v]
+	s := m[name]
+	if s != nil {
+		return s
+	}
+	s = syms.Newsym(name, v)
+	m[name] = s
+	return s
+}
+
+// Look up the symbol with the given name and version, returning nil
+// if it is not found.
+func (syms *Symbols) ROLookup(name string, v int) *Symbol {
+	return syms.hash[v][name]
+}
+
+// Add an existing symbol to the symbol table.
+func (syms *Symbols) Add(s *Symbol) {
+	name := s.Name
+	v := int(s.Version)
+	m := syms.hash[v]
+	if _, ok := m[name]; ok {
+		panic(name + " already added")
+	}
+	m[name] = s
+}
+
+// Allocate a new version (i.e. symbol namespace).
+func (syms *Symbols) IncVersion() int {
+	syms.hash = append(syms.hash, make(map[string]*Symbol))
+	return len(syms.hash) - 1
+}
+
+// Rename renames a symbol.
+func (syms *Symbols) Rename(old, new string, v int, reachparent map[*Symbol]*Symbol) {
+	s := syms.hash[v][old]
+	oldExtName := s.Extname()
+	s.Name = new
+	if oldExtName == old {
+		s.SetExtname(new)
+	}
+	delete(syms.hash[v], old)
+
+	dup := syms.hash[v][new]
+	if dup == nil {
+		syms.hash[v][new] = s
+	} else {
+		if s.Type == 0 {
+			dup.Attr |= s.Attr
+			if s.Attr.Reachable() && reachparent != nil {
+				reachparent[dup] = reachparent[s]
+			}
+			*s = *dup
+		} else if dup.Type == 0 {
+			s.Attr |= dup.Attr
+			if dup.Attr.Reachable() && reachparent != nil {
+				reachparent[s] = reachparent[dup]
+			}
+			*dup = *s
+			syms.hash[v][new] = s
+		}
+	}
+}