...

compiler/NubType.cs

@@ -1,3 +1,5 @@
+using System.Text;
+
 namespace Compiler;
 
 public abstract class NubType
@@ -153,6 +155,8 @@ public sealed class NubTypeFunc : NubType
     public IReadOnlyList<NubType> Parameters { get; }
     public NubType ReturnType { get; }
 
+    public string MangledName(string name, string module) => SymbolNameGen.Exported(name, module, this);
+
     private NubTypeFunc(List<NubType> parameters, NubType returnType)
     {
         Parameters = parameters;
@@ -162,4 +166,110 @@ public sealed class NubTypeFunc : NubType
     public override string ToString() => $"func({string.Join(' ', Parameters)}): {ReturnType}";
 
     private readonly record struct Signature(IReadOnlyList<NubType> Parameters, NubType ReturnType);
-}
+}
+
+static class TypeMangler
+{
+    public static string Encode(NubType type)
+    {
+        var sb = new StringBuilder();
+        Encode(type, sb);
+        return sb.ToString();
+    }
+
+    private static void Encode(NubType type, StringBuilder sb)
+    {
+        switch (type)
+        {
+            case NubTypeVoid:
+                sb.Append('V');
+                break;
+
+            case NubTypeBool:
+                sb.Append('B');
+                break;
+
+            case NubTypeUInt u:
+                sb.Append("U(");
+                sb.Append(u.Width);
+                sb.Append(')');
+                break;
+
+            case NubTypeSInt s:
+                sb.Append("U(");
+                sb.Append(s.Width);
+                sb.Append(')');
+                break;
+
+            case NubTypeString:
+                sb.Append('S');
+                break;
+
+            case NubTypePointer p:
+                sb.Append("P(");
+                Encode(p.To, sb);
+                sb.Append(')');
+                break;
+
+            case NubTypeStruct st:
+                sb.Append($"T({st.Module}::{st.Name})").Append(st.Module).Append("::").Append(st.Name).Append(')');
+                break;
+
+            case NubTypeFunc fn:
+                sb.Append("F(");
+                for (int i = 0; i < fn.Parameters.Count; i++)
+                {
+                    Encode(fn.Parameters[i], sb);
+                    sb.Append(',');
+                }
+                Encode(fn.ReturnType, sb);
+                sb.Append(')');
+                break;
+
+            default:
+                throw new NotSupportedException(type.GetType().Name);
+        }
+    }
+}
+
+static class Hashing
+{
+    public static ulong Fnv1a64(string text)
+    {
+        const ulong offset = 14695981039346656037UL;
+        const ulong prime  = 1099511628211UL;
+
+        ulong hash = offset;
+        foreach (var c in Encoding.UTF8.GetBytes(text))
+        {
+            hash ^= c;
+            hash *= prime;
+        }
+
+        return hash;
+    }
+}
+
+static class SymbolNameGen
+{
+    public static string Exported(string module, string function, NubType type)
+    {
+        var canonical = TypeMangler.Encode(type);
+        var hash = Hashing.Fnv1a64(canonical);
+
+        return $"nub_{Sanitize(module)}_{Sanitize(function)}_{hash:x16}";
+    }
+
+    private static string Sanitize(string s)
+    {
+        var sb = new StringBuilder(s.Length);
+        foreach (var c in s)
+        {
+            if (char.IsLetterOrDigit(c))
+                sb.Append(c);
+            else
+                sb.Append('_');
+        }
+        return sb.ToString();
+    }
+}