// Obfuscate all local symbols
// - enumerate all local symbols and tell the symbol allocator
// that it can be obfuscated.
// - where there are `holes` in the rank mapping, tell the symbol
// allocator to reserve those symbols. These holes are to be
// filled by higher frequency symbols on the inner scopes.
public void ObfuscateSymbols(RenderContext ctx, SymbolFrequency SymbolFrequency, SymbolAllocator Allocator, string prefix)
{
// Walk through local symbols
int expectedRank = 0;
foreach (var symbol in SymbolFrequency.Sort())
{
// Ignore public symbols
if (symbol.Accessibility != Accessibility.Private)
continue;
// Ignore non-local symbols
if (symbol.Scope != Symbol.ScopeType.local)
continue;
// Reserve space for inner, higher frequency symbols
if (symbol.Rank > expectedRank)
{
if (ctx.Compiler.Formatted && ctx.Compiler.SymbolInfo)
{
for (int r = expectedRank; r < symbol.Rank; r++)
{
ctx.StartLine();
ctx.AppendFormat("// #{0} reserved", r);
}
}
Allocator.ReserveObfuscatedSymbols(symbol.Rank - expectedRank);
}
string newSymbol = Allocator.OnfuscateSymbol(symbol.Name);
// Show info
if (ctx.Compiler.Formatted && ctx.Compiler.SymbolInfo)
{
ctx.StartLine();
ctx.AppendFormat("// #{0} {3}{1} -> {3}{2}", symbol.Rank, symbol.Name, newSymbol, prefix);
}
expectedRank = symbol.Rank + 1;
}
}
// Prepare symbol ranks of all local symbols
// - For each inner scope, merge this symbol frequency map
// of this scope with that of the inner scope
// - Update the rank of each symbol
// - Repeat for each inner scope
public void Prepare()
{
// Recurse through all scopes
foreach (var i in InnerScopes)
{
i.Prepare();
}
// Apply default accessibility to own local symbols
foreach (var i in Symbols)
{
if (i.Value.Accessibility == Accessibility.Default)
{
i.Value.Accessibility = DefaultAccessibility;
}
}
// Calculate base rank based on frequency of our own
// local symbols
Symbols.UpdateRanks(Symbols.Sort());
// Merge each inner scope and update ranks
foreach (var i in InnerScopes)
{
var merged = new SymbolFrequency();
merged.CopyFrom(Symbols);
merged.MergeSymbols(i.AllSymbols);
Symbols.UpdateRanks(merged.Sort());
}
// Member symbol
Members.UpdateRanks(Members.Sort());
foreach (var i in InnerScopes)
{
var merged = new SymbolFrequency();
merged.CopyFrom(Members);
merged.MergeSymbols(i.AllMembers);
Members.UpdateRanks(merged.Sort());
}
}
// Dump to stdout
public void Dump(int indent)
{
Utils.WriteIndentedLine(indent, "Scope: {0}", Node);
if (Symbols.Sort().Count>0)
{
Utils.WriteIndentedLine(indent + 1, "Local Symbols:");
Symbols.Dump(indent + 2);
}
foreach (var i in InnerScopes)
{
var merged = new SymbolFrequency();
merged.CopyFrom(Symbols);
merged.MergeSymbols(i.AllSymbols);
if (merged.Sort().Count > 0)
{
Utils.WriteIndentedLine(indent + 1, "Symbols after merge with {0}:", i.Node);
merged.Dump(indent + 2);
}
}
foreach (var i in InnerScopes)
{
i.Dump(indent + 1);
}
}
