...

example/c.nub

@@ -1,4 +1,4 @@
 namespace c
 
 // extern func printf(fmt: ^u8, ...args: any): void
-extern func puts(fmt: []u8)
+extern func puts(fmt: cstring)

example/main.nub

@@ -1,7 +1,7 @@
 namespace main
 
-export func main(args: [][]u8): i64 {
+export func main(args: []cstring): i64 {
-    let x: []u8
+    let x: cstring
 
     x = args[0]
 

src/CLI/Program.cs

@@ -89,6 +89,10 @@ foreach (var compilationUnit in compilationUnits)
     File.WriteAllText(ssaPath, ssa);
     
     var asm = await QBE.Invoke(ssa);
+    if (asm == null)
+    {
+        return 1;
+    }
 
     var asmPath = Path.ChangeExtension(outputPath, "s");
     await File.WriteAllTextAsync(asmPath, asm);

src/CLI/QBE.cs

@@ -4,7 +4,7 @@ namespace CLI;
 
 public static class QBE
 {
-    public static async Task<string> Invoke(string ssa)
+    public static async Task<string?> Invoke(string ssa)
     {
         using var qbeProcess = new Process();
         qbeProcess.StartInfo = new ProcessStartInfo
@@ -22,16 +22,16 @@ public static class QBE
         await qbeProcess.StandardInput.WriteAsync(ssa);
         qbeProcess.StandardInput.Close();
 
-        var assemblyCode = await qbeProcess.StandardOutput.ReadToEndAsync();
-        var qbeErrors = await qbeProcess.StandardError.ReadToEndAsync();
-
         await qbeProcess.WaitForExitAsync();
 
-        if (qbeProcess.ExitCode != 0)
+        var qbeErrors = await qbeProcess.StandardError.ReadToEndAsync();
+        if (!string.IsNullOrWhiteSpace(qbeErrors))
         {
-            throw new Exception($"QBE error:\n{qbeErrors}");
+            await Console.Error.WriteLineAsync("qbe error:\n" + qbeErrors);
         }
 
-        return assemblyCode;
+        var asm = await qbeProcess.StandardOutput.ReadToEndAsync();
+
+        return qbeProcess.ExitCode == 0 ? asm : null;
     }
 }

src/CLI/Runtime/nub_string.s

@@ -1,7 +1,6 @@
 .intel_syntax noprefix
 
 .equ SYS_MMAP, 9
-.equ SYS_MUNMAP, 11
 
 .text
 .globl nub_strlen
@@ -79,22 +78,3 @@ function_exit:
     pop r12
     pop rbx
     ret
-
-.text
-.globl nub_string_free
-# func nub_string_free(string: []u8): void
-nub_string_free:
-    test rdi, rdi
-    jz free_exit
-
-    mov rsi, [rdi]
-    add rsi, 8
-
-    # Round up to page size
-    add rsi, 4095
-    and rsi, -4096
-
-    mov rax, SYS_MUNMAP
-    syscall
-free_exit:
-    ret

src/Generation/QBE/QBEGenerator.cs

@@ -122,6 +122,7 @@ public static class QBEGenerator
             NubStructType => "storel",
             NubFixedArrayType => "storel",
             NubFuncType => "storel",
+            NubCStringType => "storel",
             _ => throw new NotSupportedException($"'{type}' type cannot be used in store instructions")
         };
     }
@@ -150,6 +151,7 @@ public static class QBEGenerator
             NubStructType => "loadl",
             NubFixedArrayType => "loadl",
             NubFuncType => "loadl",
+            NubCStringType => "loadl",
             _ => throw new NotSupportedException($"'{type}' type cannot be used in load instructions")
         };
     }
@@ -178,6 +180,7 @@ public static class QBEGenerator
             NubStructType => "=l",
             NubFixedArrayType => "=l",
             NubFuncType => "=l",
+            NubCStringType => "=l",
             _ => throw new NotSupportedException($"'{type}' type cannot be used in variables")
         };
     }
@@ -204,6 +207,7 @@ public static class QBEGenerator
             }
             case NubPointerType:
             case NubArrayType:
+            case NubCStringType:
             case NubFuncType:
             {
                 return 8;
@@ -263,6 +267,7 @@ public static class QBEGenerator
             }
             case NubPointerType:
             case NubArrayType:
+            case NubCStringType:
             case NubFuncType:
             {
                 return 8;
@@ -300,16 +305,7 @@ public static class QBEGenerator
 
     private static bool IsPointerType(NubType type)
     {
-        return type switch
+        return type is NubStructType or NubArrayType or NubFixedArrayType;
-        {
-            NubPointerType => false,
-            NubPrimitiveType => false,
-            NubStructType => true,
-            NubArrayType => true,
-            NubFixedArrayType => true,
-            NubFuncType => false,
-            _ => throw new ArgumentOutOfRangeException(nameof(type))
-        };
     }
 
     private static void GenerateFuncDefinition(string name, List<FuncParameter> parameters, NubType returnType, BlockNode body, bool exported)
@@ -347,6 +343,7 @@ public static class QBEGenerator
                 NubStructType structType => StructName(_definitionTable.LookupStruct(structType.Namespace, structType.Name).GetValue()),
                 NubFixedArrayType => "l",
                 NubFuncType => "l",
+                NubCStringType => "l",
                 _ => throw new NotSupportedException($"'{returnType}' type cannot be used as a function return type")
             });
             _builder.Append(' ');
@@ -378,6 +375,7 @@ public static class QBEGenerator
                 NubStructType structType => StructName(_definitionTable.LookupStruct(structType.Namespace, structType.Name).GetValue()),
                 NubFixedArrayType => "l",
                 NubFuncType => "l",
+                NubCStringType => "l",
                 _ => throw new NotSupportedException($"'{parameter.Type}' type cannot be used as a function parameter type")
             };
 
@@ -459,6 +457,7 @@ public static class QBEGenerator
                 NubStructType structType => StructName(_definitionTable.LookupStruct(structType.Namespace, structType.Name).GetValue()),
                 NubFixedArrayType fixedArrayType => $"b {SizeOf(fixedArrayType)}",
                 NubFuncType => "l",
+                NubCStringType => "l",
                 _ => throw new NotSupportedException($"'{structDefinitionField.Type}' type cannot be used in structs")
             };
             _builder.Append(qbeType + ", ");
@@ -1200,13 +1199,20 @@ public static class QBEGenerator
         var item = GenerateExpression(memberAccess.Expression);
         switch (memberAccess.Expression.Type)
         {
-            case NubArrayType:
+            case NubArrayType arrayType:
             {
                 if (memberAccess.Member == "count")
                 {
                     return item;
                 }
                 
+                if (arrayType.ElementType is NubPrimitiveType { Kind: PrimitiveTypeKind.U8 } && memberAccess.Member == "cstring")
+                {
+                    var result = VarName();
+                    _builder.AppendLine($"    {result} =l call $nub_string_to_cstring(l {item})");
+                    return result;
+                }
+
                 throw new UnreachableException(nameof(memberAccess.Member));
             }
             case NubStructType structType:
@@ -1291,6 +1297,7 @@ public static class QBEGenerator
                 NubStructType structType => StructName(_definitionTable.LookupStruct(structType.Namespace, structType.Name).GetValue()),
                 NubFixedArrayType => "l",
                 NubFuncType => "l",
+                NubCStringType => "l",
                 _ => throw new NotSupportedException($"'{parameter.Type}' type cannot be used in function calls")
             };
             parameterStrings.Add($"{qbeType} {result}");

src/Syntax/Parsing/Parser.cs

@@ -670,6 +670,11 @@ public static class Parser
                 return new NubArrayType(NubPrimitiveType.U8);
             }
 
+            if (name.Value == "cstring")
+            {
+                return new NubCStringType();
+            }
+
             if (NubPrimitiveType.TryParse(name.Value, out var primitiveTypeKind))
             {
                 return new NubPrimitiveType(primitiveTypeKind.Value);

src/Syntax/Typing/NubType.cs

@@ -48,6 +48,24 @@ public abstract class NubType
     public abstract override string ToString();
 }
 
+public class NubCStringType : NubType
+{
+    public override bool Equals(object? obj)
+    {
+        return obj is NubCStringType other;
+    }
+
+    public override int GetHashCode()
+    {
+        return "cstring".GetHashCode();
+    }
+
+    public override string ToString()
+    {
+        return "cstring";
+    }
+}
+
 public class NubFuncType(NubType returnType, List<NubType> parameters) : NubType
 {
     public NubType ReturnType { get; } = returnType;
@@ -163,7 +181,7 @@ public class NubAnyType : NubType
 
     public override int GetHashCode()
     {
-        return GetType().GetHashCode();
+        return "any".GetHashCode();
     }
 }
 

src/Syntax/Typing/TypeChecker.cs

@@ -422,12 +422,6 @@ public static class TypeChecker
         var exprType = CheckExpression(addressOf.Expression);
         if (exprType == null) return null;
 
-        if (addressOf.Expression is not (IdentifierNode or MemberAccessNode))
-        {
-            ReportError($"Cannot take the address of {exprType}", addressOf.Expression);
-            return null;
-        }
-
         return new NubPointerType(exprType);
     }
 
@@ -569,13 +563,18 @@ public static class TypeChecker
 
         switch (expressionType)
         {
-            case NubArrayType:
+            case NubArrayType arrayType:
             {
                 if (memberAccess.Member == "count")
                 {
                     return NubPrimitiveType.I64;
                 }
 
+                if (arrayType.ElementType is NubPrimitiveType { Kind: PrimitiveTypeKind.U8 } && memberAccess.Member == "cstring")
+                {
+                    return new NubCStringType();
+                }
+
                 break;
             }
             case NubStructType structType:

tools/syntax-highlighting/syntaxes/nub.tmLanguage.json

@@ -79,7 +79,7 @@
         },
         {
           "name": "storage.type.primitive.nub",
-          "match": "\\b(i8|i16|i32|i64|u8|u16|u32|u64|f32|f64|bool|string|void|any)\\b"
+          "match": "\\b(i8|i16|i32|i64|u8|u16|u32|u64|f32|f64|bool|string|cstring|void|any)\\b"
         },
         {
           "name": "storage.type.array.nub",