feat(compiler): Enable single-file compilation

cli/bin/grain.js

@@ -188,6 +188,10 @@ program
   .command("compile <file>")
   .description("compile a grain program into wasm")
   .forwardOption("-o <filename>", "output filename")
+  .forwardOption(
+    "--single-file",
+    "compile a single file without compiling dependencies"
+  )
   .forwardOption(
     "--use-start-section",
     "replaces the _start export with a start section during linking"

compiler/grainc/grainc.re

@@ -1,4 +1,5 @@
 open Grain;
+open Grain_typed;
 open Compile;
 open Printf;
 open Lexing;
@@ -26,24 +27,8 @@ let () =
     }
   );
 
-let compile_file = (name, outfile_arg) => {
-  if (!Printexc.backtrace_status() && Grain_utils.Config.verbose^) {
-    Printexc.record_backtrace(true);
-  };
-  try({
-    let outfile =
-      Option.value(
-        ~default=Compile.default_wasm_filename(name),
-        outfile_arg,
-      );
-    let hook =
-      if (Grain_utils.Config.statically_link^) {
-        Compile.stop_after_assembled;
-      } else {
-        Compile.stop_after_object_emitted;
-      };
-    ignore(Compile.compile_file(~is_root_file=true, ~hook, ~outfile, name));
-  }) {
+let error_wrapped = f =>
+  try(f()) {
   | exn =>
     let bt =
       if (Printexc.backtrace_status()) {
@@ -63,6 +48,59 @@ let compile_file = (name, outfile_arg) => {
     );
     exit(2);
   };
+
+let compile_file = (~outfile=?, filename) => {
+  let outfile =
+    Option.value(
+      ~default=Compile.default_object_filename(filename),
+      outfile,
+    );
+  ignore(Compile.compile_file(~outfile, filename));
+};
+let compile_file = (~outfile=?, filename) =>
+  error_wrapped(() => compile_file(~outfile?, filename));
+
+let grainc = (single_file_mode, name, outfile) => {
+  Grain_utils.Config.set_root_config();
+
+  if (!Printexc.backtrace_status() && Grain_utils.Config.verbose^) {
+    Printexc.record_backtrace(true);
+  };
+
+  if (single_file_mode) {
+    compile_file(~outfile?, name);
+  } else {
+    switch (Grain_utils.Config.wasi_polyfill^) {
+    | Some(name) =>
+      Grain_utils.Config.preserve_config(() => {
+        Grain_utils.Config.compilation_mode := Grain_utils.Config.Runtime;
+        Module_resolution.load_dependency_graph(name);
+        let to_compile = Module_resolution.get_out_of_date_dependencies();
+        List.iter(compile_file, to_compile);
+        compile_file(name);
+      })
+    | None => ()
+    };
+
+    Module_resolution.load_dependency_graph(name);
+    let to_compile = Module_resolution.get_out_of_date_dependencies();
+    List.iter(compile_file, to_compile);
+    compile_file(name);
+
+    if (Grain_utils.Config.statically_link^) {
+      let main_object =
+        Option.value(
+          ~default=Compile.default_object_filename(name),
+          outfile,
+        );
+      let outfile =
+        Option.value(~default=Compile.default_wasm_filename(name), outfile);
+      let dependencies = Module_resolution.get_dependencies();
+
+      Link.link(~main_object, ~outfile, dependencies);
+    };
+  };
+
   `Ok();
 };
 
@@ -107,6 +145,11 @@ let output_filename = {
   );
 };
 
+let single_file_mode = {
+  let doc = sprintf("Compile a single file without compiling dependencies");
+  Arg.(value & vflag(false, [(true, info(["single-file"], ~doc))]));
+};
+
 let cmd = {
   let doc = sprintf("Compile Grain programs");
   let version =
@@ -118,7 +161,8 @@ let cmd = {
     Cmd.info(Sys.argv[0], ~version, ~doc),
     Term.(
       ret(
-        Grain_utils.Config.with_cli_options(compile_file)
+        Grain_utils.Config.with_cli_options(grainc)
+        $ single_file_mode
         $ input_filename
         $ output_filename,
       )

compiler/graindoc/docblock.re

@@ -330,7 +330,7 @@ let get_comments_from_loc = (loc: Grain_parsing.Location.t) => {
   | Some(comments) => comments
   | None =>
     let comments =
-      switch (compile_file(~is_root_file=true, ~hook=stop_after_parse, file)) {
+      switch (compile_file(~hook=stop_after_parse, file)) {
       | exception exn => []
       | {cstate_desc: Parsed(parsed_program)} => parsed_program.comments
       | _ => failwith("Invalid compilation state")

compiler/graindoc/graindoc.re

@@ -47,14 +47,26 @@ type params = {
   current_version: option(string),
 };
 
-let compile_typed = (input: Fp.t(Fp.absolute)) => {
-  switch (
-    Compile.compile_file(
-      ~is_root_file=true,
-      ~hook=stop_after_typed,
-      Filepath.to_string(input),
-    )
-  ) {
+let compile_typed = file => {
+  Module_resolution.load_dependency_graph(file);
+  let to_compile = Module_resolution.get_out_of_date_dependencies();
+  List.iter(
+    file =>
+      ignore(
+        compile_file(
+          ~hook=stop_after_object_emitted,
+          ~outfile=Compile.default_wasm_filename(file),
+          file,
+        ),
+      ),
+    to_compile,
+  );
+  compile_file(~hook=stop_after_typed, file);
+};
+
+let compile = (input: Fp.t(Fp.absolute)) => {
+  reset_compiler_state();
+  switch (compile_typed(Filepath.to_string(input))) {
   | exception exn =>
     let bt =
       if (Printexc.backtrace_status()) {
@@ -180,9 +192,11 @@ let enumerate_runs = opts =>
   };
 
 let graindoc = (opts, runs) => {
+  Config.set_root_config();
+
   List.iter(
     ({input_path, output_path}) => {
-      let program = compile_typed(input_path);
+      let program = compile(input_path);
       try(
         generate_docs(
           ~current_version=opts.current_version,

compiler/src/codegen/linkedtree.re

@@ -29,9 +29,7 @@ let max_stack_size = (s1, s2) => {
 
 let wasi_module = "wasi_snapshot_preview1";
 
-let link = main_mashtree => {
-  let main_module = Module_resolution.current_filename^();
-
+let link = (~main_object, dependencies) => {
   let new_base_dir = Filepath.String.dirname;
 
   let resolve = (~base_dir=?, mod_name) =>
@@ -43,7 +41,6 @@ let link = main_mashtree => {
       Config.wasi_polyfill_path(),
     );
 
-  let dependencies = Module_resolution.get_dependencies();
   let dependencies =
     switch (wasi_polyfill) {
     | Some(polyfill) => [polyfill, ...dependencies]
@@ -199,7 +196,8 @@ let link = main_mashtree => {
       dependencies,
     );
 
-  let main_program = process_mashtree(~main=true, main_module, main_mashtree);
+  let main_mashtree = Emitmod.load_object(main_object);
+  let main_program = process_mashtree(~main=true, main_object, main_mashtree);
   let programs = List.rev([main_program, ...programs]);
   let num_function_table_elements = num_function_table_elements^;
   let signature = main_mashtree.signature;