print builtin

compiler/lowerer.ts

@@ -134,7 +134,28 @@ export class Lowerer {
         for (const { ident } of stmt.kind.params) {
             this.locals.allocSym(ident);
         }
-        this.lowerExpr(stmt.kind.body);
+        if (stmt.kind.anno?.ident === "builtin") {
+            const anno = stmt.kind.anno.values[0];
+            if (!anno) {
+                throw new Error("builtin annotation without ident");
+            }
+            if (anno.kind.type !== "ident") {
+                throw new Error("builtin annotation without ident");
+            }
+            const value = anno.kind.value;
+            switch (value) {
+                case "print": {
+                    this.program.add(Ops.LoadLocal, 0);
+                    this.program.add(Ops.Builtin, Builtins.Print);
+                    break;
+                }
+                default: {
+                    throw new Error("unrecognized builtin");
+                }
+            }
+        } else {
+            this.lowerExpr(stmt.kind.body);
+        }
         this.locals = outerLocals;
 
         const localAmount = fnRoot.stackReserved() -

examples/annos.slg

@@ -3,5 +3,5 @@ fn print(msg: string) #[builtin(print)] {
 }
 
 fn main() {
-    print("hello world!");
+    print("hello world!\n");
 }

runtime/arch.hpp

@@ -43,6 +43,7 @@ enum class Builtin : uint32_t {
     StringEqual = 0x11,
     ArraySet = 0x20,
     StructSet = 0x30,
+    Print = 0x40,
 };
 
 }

runtime/vm.cpp

@@ -68,8 +68,8 @@ void VM::run_n_instructions(size_t amount)
 
 void VM::run_instruction()
 {
-    std::cout << std::format("    {:>4}: {:<12}{}\n", this->pc,
-        maybe_op_to_string(this->program[this->pc]), stack_repr_string(8));
+    // std::cout << std::format("    {:>4}: {:<12}{}\n", this->pc,
+    //     maybe_op_to_string(this->program[this->pc]), stack_repr_string(8));
     auto op = eat_op();
     switch (op) {
         case Op::Nop:
@@ -339,5 +339,11 @@ void VM::run_builtin(Builtin builtin_id)
             std::exit(1);
             break;
         }
+        case Builtin::Print: {
+            assert_stack_has(1);
+            auto message = stack_pop().as_string().value;
+            std::cout << message;
+            break;
+        }
     }
 }