feat!: Rework preopened directories (grain-lang#1656)

* feat!: Rework preopened directories

* Update stdlib/sys/file.gr

Co-authored-by: Blaine Bublitz <blaine.bublitz@gmail.com>

* remove failure case

* Add `@since` to open

---------

Co-authored-by: Blaine Bublitz <blaine.bublitz@gmail.com>

cli/bin/grain.js

@@ -119,6 +119,7 @@ class GrainCommand extends commander.Command {
       num
     );
     cmd.forwardOption("--import-memory", "import the memory from `env.memory`");
+    cmd.option("--dir <dir...>", "directory to preopen");
     cmd.forwardOption(
       "--compilation-mode <mode>",
       "compilation mode (advanced use only)"

cli/bin/run.js

@@ -6,10 +6,19 @@ module.exports = async function run(filename, options) {
   let basePath = path.dirname(filename);
   let includeDirs = [basePath, ...options.includeDirs, options.stdlib];
   let locator = runner.defaultFileLocator(includeDirs);
+
+  let preopens = {};
+  options.dir?.forEach((preopen) => {
+    let [guestDir, hostDir = guestDir] = preopen.split("=");
+    preopens[guestDir] = hostDir;
+  });
+
   let GrainRunner = runner.buildGrainRunner(locator, {
     initialMemoryPages: options.initialMemoryPages,
     maximumMemoryPages: options.maximumMemoryPages,
+    preopenDirs: preopens,
   });
+
   if (options.printOutput) {
     let result = await GrainRunner.runFileUnboxed(filename);
     await GrainRunner.ensureStringModule();

compiler/test/TestFramework.re

@@ -23,6 +23,7 @@ let () =
 
 let test_dir = Fp.At.(Filepath.get_cwd() / "test");
 let test_libs_dir = Fp.At.(test_dir / "test-libs");
+let test_data_dir = Fp.At.(test_dir / "test-data");
 let test_input_dir = Fp.At.(test_dir / "input");
 let test_output_dir = Fp.At.(test_dir / "output");
 let test_stdlib_dir = Fp.At.(test_dir / "stdlib");

compiler/test/runner.re

@@ -166,11 +166,18 @@ let run = (~num_pages=?, file) => {
 
   let stdlib = Option.get(Grain_utils.Config.stdlib_dir^);
 
+  let preopen =
+    Printf.sprintf(
+      "--dir=%s=%s",
+      "/test/test-data",
+      Filepath.to_string(test_data_dir),
+    );
+
   let cmd =
     Array.concat([
       [|"grain", "run"|],
       mem_flags,
-      [|"-S", stdlib, "-I", Filepath.to_string(test_libs_dir)|],
+      [|"-S", stdlib, "-I", Filepath.to_string(test_libs_dir), preopen|],
       [|file|],
     ]);
 

compiler/test/stdlib/sys.file.test.gr

@@ -6,10 +6,44 @@ include "result"
 
 // fdRead
 let foo = Result.unwrap(
-  Fs.pathOpen(
-    Fs.pwdfd,
-    [Fs.SymlinkFollow],
-    "test/test-data/foo.txt",
+  Fs.open("test/test-data/foo.txt", [Fs.Create], [Fs.FdRead], [Fs.FdRead], [])
+)
+
+let (buf, nread) = Result.unwrap(Fs.fdRead(foo, 40))
+
+Fs.fdClose(foo)
+
+assert buf == Bytes.fromString("foo, bar, & baz")
+assert nread == 15
+
+// Check absolute path
+let foo = Result.unwrap(
+  Fs.open("/test/test-data/foo.txt", [Fs.Create], [Fs.FdRead], [Fs.FdRead], [])
+)
+
+let (buf, nread) = Result.unwrap(Fs.fdRead(foo, 40))
+
+Fs.fdClose(foo)
+
+assert buf == Bytes.fromString("foo, bar, & baz")
+assert nread == 15
+
+// Check relative to current directory
+let foo = Result.unwrap(
+  Fs.open("./test/test-data/foo.txt", [Fs.Create], [Fs.FdRead], [Fs.FdRead], [])
+)
+
+let (buf, nread) = Result.unwrap(Fs.fdRead(foo, 40))
+
+Fs.fdClose(foo)
+
+assert buf == Bytes.fromString("foo, bar, & baz")
+assert nread == 15
+
+// Check path resolution
+let foo = Result.unwrap(
+  Fs.open(
+    "/test/test-data/../test-data/foo.txt",
     [Fs.Create],
     [Fs.FdRead],
     [Fs.FdRead],
@@ -26,9 +60,7 @@ assert nread == 15
 
 // fdWrite
 let foo = Result.unwrap(
-  Fs.pathOpen(
-    Fs.pwdfd,
-    [Fs.SymlinkFollow],
+  Fs.open(
     "test/test-data/bar.txt",
     [Fs.Create, Fs.Truncate],
     [Fs.FdRead, Fs.FdWrite, Fs.FdSeek, Fs.FdSetSize],

js-runner/src/core/grain-module.js

@@ -1,43 +1,5 @@
-import { WASI } from "@wasmer/wasi/lib/index.cjs";
-import { WasmFs } from "@wasmer/wasmfs";
 import wasmmap from "wasm-sourcemap";
 
-let bindings;
-
-if (__RUNNER_BROWSER) {
-  const wasmFs = new WasmFs();
-  const decoder = new TextDecoder("utf-8");
-  // Monkeypatching the writeSync for stdout/stderr printing
-  const originalWriteSync = wasmFs.fs.writeSync;
-  wasmFs.fs.writeSync = (fd, buf, offset, length, position) => {
-    if (fd === 1) {
-      console.log(decoder.decode(buf));
-      return;
-    }
-    if (fd === 2) {
-      console.error(decoder.decode(buf));
-      return;
-    }
-
-    originalWriteSync(fd, buf, offset, length, position);
-  };
-  bindings = {
-    ...wasiBindings.default,
-    fs: wasmFs.fs,
-  };
-} else {
-  bindings = wasiBindings.default;
-}
-
-export const wasi = new WASI({
-  args: __RUNNER_BROWSER ? [] : process.argv,
-  env: __RUNNER_BROWSER ? {} : process.env,
-  bindings,
-  preopens: {
-    "/sandbox": __RUNNER_BROWSER ? "" : process.cwd(),
-  },
-});
-
 export class GrainModule {
   constructor(wasmModule, name) {
     this.wasmModule = wasmModule;
@@ -124,11 +86,11 @@ export class GrainModule {
     return this.requiredExport("_gtype_metadata")();
   }
 
-  start() {
+  start(wasi) {
     wasi.start(this.instantiated);
   }
 
-  runUnboxed() {
+  runUnboxed(wasi) {
     // Only the tests currently rely on this.
     wasi.setMemory(this.requiredExport("memory"));
     return this.requiredExport("_gmain")();

js-runner/src/core/runner.js

@@ -1,6 +1,35 @@
-import { wasi, readFile, readURL, readBuffer } from "./grain-module";
+import { WASI } from "@wasmer/wasi/lib/index.cjs";
+import { WasmFs } from "@wasmer/wasmfs";
+import { readFile, readURL, readBuffer } from "./grain-module";
 import { GRAIN_STRING_HEAP_TAG, GRAIN_GENERIC_HEAP_TAG_TYPE } from "./tags";
 
+let bindings;
+
+if (__RUNNER_BROWSER) {
+  const wasmFs = new WasmFs();
+  const decoder = new TextDecoder("utf-8");
+  // Monkeypatching the writeSync for stdout/stderr printing
+  const originalWriteSync = wasmFs.fs.writeSync;
+  wasmFs.fs.writeSync = (fd, buf, offset, length, position) => {
+    if (fd === 1) {
+      console.log(decoder.decode(buf));
+      return;
+    }
+    if (fd === 2) {
+      console.error(decoder.decode(buf));
+      return;
+    }
+
+    originalWriteSync(fd, buf, offset, length, position);
+  };
+  bindings = {
+    ...wasiBindings.default,
+    fs: wasmFs.fs,
+  };
+} else {
+  bindings = wasiBindings.default;
+}
+
 const MALLOC_MODULE = "GRAIN$MODULE$runtime/gc";
 const STRING_MODULE = "GRAIN$MODULE$runtime/string";
 
@@ -24,6 +53,12 @@ export class GrainRunner {
       element: "anyfunc",
       initial: 1024,
     });
+    this.wasi = new WASI({
+      args: __RUNNER_BROWSER ? [] : process.argv,
+      env: __RUNNER_BROWSER ? {} : process.env,
+      bindings,
+      preopens: opts.preopenDirs,
+    });
   }
 
   get memoryManager() {
@@ -52,7 +87,7 @@ export class GrainRunner {
       throw new Error(`Failed to ensure string module.`);
     }
     await this.load(STRING_MODULE, located);
-    located.start();
+    located.start(this.wasi);
   }
 
   grainValueToString(v) {
@@ -117,7 +152,7 @@ export class GrainRunner {
           continue;
         }
         if (imp.module.startsWith("wasi_")) {
-          Object.assign(this.imports, wasi.getImports(mod.wasmModule));
+          Object.assign(this.imports, this.wasi.getImports(mod.wasmModule));
           continue;
         }
         // Should return an instance of GrainModule
@@ -135,7 +170,7 @@ export class GrainRunner {
           located.loadTypeMetadata();
         }
         if (located.isStartable) {
-          located.start();
+          located.start(this.wasi);
         }
         this.ptrZero = this.ptr;
         this.imports[imp.module] = located.exports;
@@ -166,12 +201,12 @@ export class GrainRunner {
 
   async runFileUnboxed(path) {
     let module = await this.loadFile(path);
-    return module.runUnboxed();
+    return module.runUnboxed(this.wasi);
   }
 
   async runFile(path) {
     let module = await this.loadFile(path);
-    return module.start();
+    return module.start(this.wasi);
   }
 
   async loadURL(url) {
@@ -181,12 +216,12 @@ export class GrainRunner {
 
   async runURL(path) {
     let module = await this.loadURL(path);
-    return module.start();
+    return module.start(this.wasi);
   }
 
   async runURLUnboxed(path) {
     let module = await this.loadURL(path);
-    return module.runUnboxed();
+    return module.runUnboxed(this.wasi);
   }
 
   async loadBuffer(buffer) {
@@ -196,11 +231,11 @@ export class GrainRunner {
 
   async runBuffer(buffer) {
     let module = await this.loadBuffer(buffer);
-    return module.start();
+    return module.start(this.wasi);
   }
 
   async runBufferUnboxed(buffer) {
     let module = await this.loadBuffer(buffer);
-    return module.runUnboxed();
+    return module.runUnboxed(this.wasi);
   }
 }

stdlib/runtime/wasi.gr

@@ -65,6 +65,15 @@ provide foreign wasm fd_pread: (
   WasmI64,
   WasmI32,
 ) -> WasmI32 from "wasi_snapshot_preview1"
+provide foreign wasm fd_prestat_get: (
+  WasmI32,
+  WasmI32,
+) -> WasmI32 from "wasi_snapshot_preview1"
+provide foreign wasm fd_prestat_dir_name: (
+  WasmI32,
+  WasmI32,
+  WasmI32,
+) -> WasmI32 from "wasi_snapshot_preview1"
 /**
  * Invokes the `fd_write` system call.
  *

stdlib/runtime/wasi.md

@@ -80,6 +80,18 @@ fd_read : (WasmI32, WasmI32, WasmI32, WasmI32) -> WasmI32
 fd_pread : (WasmI32, WasmI32, WasmI32, WasmI64, WasmI32) -> WasmI32
 ```
 
+### Wasi.**fd_prestat_get**
+
+```grain
+fd_prestat_get : (WasmI32, WasmI32) -> WasmI32
+```
+
+### Wasi.**fd_prestat_dir_name**
+
+```grain
+fd_prestat_dir_name : (WasmI32, WasmI32, WasmI32) -> WasmI32
+```
+
 ### Wasi.**fd_write**
 
 ```grain