move rt to separate file and make loader understand it

src/index.ts

@@ -13,7 +13,6 @@ import { GlobalContext, parseArgs } from "./context";
 import { loadCrate } from "./loader";
 
 const INPUT = `
-extern mod a;
 type A = { a: Int };
 
 function main() = (

src/loader.ts

@@ -13,9 +13,22 @@ export function loadModuleFile(
   moduleName: string,
   span: Span
 ): LoadedFile {
+  let searchDir: string;
+  if (relativeTo.endsWith(".mod.nil")) {
+    // x/uwu.mod.nil searches in x/
+    searchDir = path.dirname(relativeTo);
+  } else if (relativeTo.endsWith(".nil")) {
+    throw new CompilerError(
+      `.nil files cannot have submodules. use .mod.nil in a subdirectory`,
+      span
+    );
+  } else {
+    searchDir = relativeTo;
+  }
+
   const options = [
-    path.join(relativeTo, `${moduleName}.nil`),
-    path.join(relativeTo, moduleName, `${moduleName}.mod.nil`),
+    path.join(searchDir, `${moduleName}.nil`),
+    path.join(searchDir, moduleName, `${moduleName}.mod.nil`),
   ];
 
   let content: string | undefined = undefined;
@@ -45,15 +58,17 @@ export const loadCrate: CrateLoader = (
   // We really, really want a good algorithm for finding crates.
   // But right now we just look for files in the CWD.
 
-  const existing = gcx.finalizedCrates.find((crate) => crate.packageName === name);
+  const existing = gcx.finalizedCrates.find(
+    (crate) => crate.packageName === name
+  );
   if (existing) {
     return existing;
   }
 
-  const file = loadModuleFile(".", name, span);
-
   return withErrorPrinter(
     (): DepCrate => {
+      const file = loadModuleFile(".", name, span);
+
       const crateId = gcx.crateId.next();
 
       const tokens = tokenize(file);

src/parser.ts

@@ -33,7 +33,14 @@ import {
   StructLiteralField,
 } from "./ast";
 import { CompilerError, LoadedFile, Span } from "./error";
-import { BaseToken, Token, TokenIdent, TokenLitString } from "./lexer";
+import {
+  BaseToken,
+  Token,
+  TokenIdent,
+  TokenLitString,
+  tokenize,
+} from "./lexer";
+import { loadModuleFile } from "./loader";
 import { ComplexMap, ComplexSet, Ids } from "./utils";
 
 export type ParseState = { tokens: Token[]; file: LoadedFile };
@@ -46,6 +53,16 @@ export function parse(
   t: State,
   crateId: number
 ): Crate<Built> {
+  const [, items] = parseItems(t);
+
+  const ast: Crate<Built> = buildCrate(packageName, items, crateId, t.file);
+
+  validateAst(ast);
+
+  return ast;
+}
+
+function parseItems(t: State): [State, Item<Parsed>[]] {
   const items: Item<Parsed>[] = [];
 
   while (t.tokens.length > 0) {
@@ -54,11 +71,7 @@ export function parse(
     items.push(item);
   }
 
-  const ast: Crate<Built> = buildCrate(packageName, items, crateId, t.file);
-
-  validateAst(ast);
-
-  return ast;
+  return [t, items];
 }
 
 function parseItem(t: State): [State, Item<Parsed>] {
@@ -165,10 +178,11 @@ function parseItem(t: State): [State, Item<Parsed>] {
     let name;
     [t, name] = expectNext<TokenIdent>(t, "identifier");
 
-    [t] = expectNext(t, "(");
-
-    const contents: Item<Parsed>[] = [];
+    let contents: Item<Parsed>[] = [];
 
+    let popen = undefined;
+    [t, popen] = eat(t, "(");
+    if (popen) {
       while (peekKind(t) !== ")") {
         let item;
         [t, item] = parseItem(t);
@@ -177,6 +191,19 @@ function parseItem(t: State): [State, Item<Parsed>] {
       }
 
       [t] = expectNext(t, ")");
+    } else {
+      if (name.span.file.path === undefined) {
+        throw new CompilerError(
+          `no known source file for statement, cannot load file relative to it`,
+          name.span
+        );
+      }
+      const file = loadModuleFile(name.span.file.path, name.ident, name.span);
+
+      const tokens = tokenize(file);
+      [, contents] = parseItems({ file, tokens });
+    }
+
     [t] = expectNext(t, ";");
 
     const node: ModItem<Parsed> = {

std/rt.nil

@@ -0,0 +1,38 @@
+// Start the heap at 1024. In practice this could probably be as low as we want.
+// TODO: The compiler should set this global to whatever it has calculated the heap
+// start to be. But well, 1024 ought to be enough for now. lol.
+global HEAD_PTR: I32 = 1024_I32;
+
+// Every struct has a header of an I32 as a refcount.
+
+// Allocate a new item. We do not deallocate anything yet.
+// lol.
+function allocateItem(objSize: I32, align: I32): I32 = (
+    if align < 4_I32 then std.abort("invalid alignment");
+
+    // Include the refcount header.
+    let actualSize = 4_I32 + objSize;
+
+    // Let's see whether we can fit the refcount into the align bits.
+    // I happen to know that everything will always be at least 4 bytes aligned.
+    let alignedPtr = std.alignUp(HEAD_PTR, align);
+    let actualObjPtr = if (alignedPtr - HEAD_PTR) > align then (
+        alignedPtr - 4_I32
+    ) else (
+        // Take up the next spot.
+        alignedPtr + align - 4_I32
+    );
+
+    let newHeadPtr = actualObjPtr + actualSize;
+
+    if newHeadPtr > __memory_size() then (
+        // 16 pages, very arbitrary.
+        let result = __memory_grow(16_I32);
+        // If allocation failed we get -1. We don't have negative numbers yet, lol.
+        if result > 4294967295_I32 then (
+            std.abort("failed to grow memory");
+        );
+    );
+
+    actualObjPtr
+);

std/std.mod.nil

@@ -1,3 +1,5 @@
+mod rt;
+
 function printlnI32(x: I32) = (
     printI32(x);
     print("\n");
@@ -65,48 +67,6 @@ function println(s: String) = (
   print("\n");
 );
 
-mod rt (
-    // Start the heap at 1024. In practice this could probably be as low as we want.
-    global BASE_PTR: I32 = 1024_I32;
-    global HEAD_PTR: I32 = 1024_I32;
-
-    /*
-    Every struct has a header of an I32 as a refcount.
-    */
-
-    // Allocate a new item. We do not deallocate anything yet.
-    // lol.
-    function allocateItem(objSize: I32, align: I32): I32 = (
-        if align < 4_I32 then std.abort("invalid alignment");
-
-        // Include the refcount header.
-        let actualSize = 4_I32 + objSize;
-
-        // Let's see whether we can fit the refcount into the align bits.
-        // I happen to know that everything will always be at least 4 bytes aligned.
-        let alignedPtr = std.alignUp(HEAD_PTR, align);
-        let actualObjPtr = if (alignedPtr - HEAD_PTR) > align then (
-            alignedPtr - 4_I32
-        ) else (
-            // Take up the next spot.
-            alignedPtr + align - 4_I32
-        );
-
-        let newHeadPtr = actualObjPtr + actualSize;
-
-        if newHeadPtr > __memory_size() then (
-            // 16 pages, very arbitrary.
-            let result = __memory_grow(16_I32);
-            // If allocation failed we get -1. We don't have negative numbers yet, lol.
-            if result > 4294967295_I32 then (
-                std.abort("failed to grow memory");
-            );
-        );
-
-        actualObjPtr
-    );
-);
-
 function alignUp(x: I32, align: I32): I32 = (x + (align - 1_I32)) & !(align - 1_I32);
 
 function i32ToInt(x: I32): Int = __i32_extend_to_i64_u(x);