Multi Entry Paths

Author: rolandpeelen

compiler/bsc/rescript_compiler_main.ml

@@ -293,6 +293,7 @@ let command_line_flags : (string * Bsc_args.spec * string) array =
       set Clflags.transparent_modules,
       "*internal*Do not record dependencies for module aliases" );
     ("-bs-gentype", set Clflags.bs_gentype, "*internal* Pass gentype command");
+    ("-bs-multi-entry", set Js_config.multi_entry, "*internal* Preserve lowercase file module names");
     (******************************************************************************)
     ( "-unboxed-types",
       set Clflags.unboxed_types,

compiler/common/js_config.ml

@@ -54,6 +54,7 @@ let jsx_module = ref React
 let jsx_preserve = ref false
 let js_stdout = ref true
 let all_module_aliases = ref false
+let multi_entry = ref false
 let no_stdlib = ref false
 let no_export = ref false
 let int_of_jsx_version = function

compiler/common/js_config.mli

@@ -88,6 +88,8 @@ val js_stdout : bool ref
 
 val all_module_aliases : bool ref
 
+val multi_entry : bool ref
+
 val no_stdlib : bool ref
 
 val no_export : bool ref

compiler/core/js_implementation.ml

@@ -20,7 +20,7 @@ let module_of_filename outputprefix =
       String.sub basename 0 pos
     with Not_found -> basename
   in
-  String.capitalize_ascii name
+  if !Js_config.multi_entry then name else String.capitalize_ascii name
 
 let fprintf = Format.fprintf
 
@@ -129,7 +129,11 @@ let after_parsing_impl ppf outputprefix (ast : Parsetree.structure) =
       output_value stdout ast);
     if !Js_config.syntax_only then Warnings.check_fatal ()
     else
-      let modulename = Ext_filename.module_name outputprefix in
+      let modulename =
+        Ext_filename.module_name
+          ~preserve_case:(!Js_config.multi_entry)
+          outputprefix
+      in
       Lam_compile_env.reset ();
       let env = Res_compmisc.initial_env ~modulename () in
       Env.set_unit_name modulename;
@@ -192,7 +196,9 @@ let implementation_map ppf sourcefile =
   seek_in ichan (Ext_digest.length + 1);
   let list_of_modules = Ext_io.rev_lines_of_chann ichan in
   close_in ichan;
-  let ns = Ext_filename.module_name sourcefile in
+  let ns =
+    Ext_filename.module_name ~preserve_case:(!Js_config.multi_entry) sourcefile
+  in
   let ml_ast =
     Ext_list.fold_left list_of_modules [] (fun acc line ->
         if Ext_string.is_empty line then acc

compiler/ext/ext_filename.ml

@@ -76,10 +76,11 @@ let new_extension name (ext : string) =
     we can not tell the difference between "x.cpp.ml" 
     and "x.ml"
 *)
-let module_name name =
+let module_name ?(preserve_case = false) name =
   let rec search_dot i name =
-    if i < 0 then Ext_string.capitalize_ascii name
-    else if String.unsafe_get name i = '.' then Ext_string.capitalize_sub name i
+    if i < 0 then if preserve_case then name else Ext_string.capitalize_ascii name
+    else if String.unsafe_get name i = '.' then
+      if preserve_case then String.sub name 0 i else Ext_string.capitalize_sub name i
     else search_dot (i - 1) name
   in
   let name = Filename.basename name in

compiler/ext/ext_filename.mli

@@ -43,7 +43,7 @@ val new_extension : string -> string -> string
 val chop_all_extensions_maybe : string -> string
 
 (* OCaml specific abstraction*)
-val module_name : string -> string
+val module_name : ?preserve_case:bool -> string -> string
 
 type module_info = {module_name: string; case: bool}
 

docs/docson/build-schema.json

@@ -364,6 +364,10 @@
       "$ref": "#/definitions/namespace-spec",
       "description": "can be true/false or a customized name"
     },
+    "multi-entry": {
+      "type": "boolean",
+      "description": "Default: false. When true, lowercase source files are compiled as private file-level modules without capitalizing their file module name. They cannot be referenced from ReScript code, are not exported through namespaces, and duplicate lowercase file stems are allowed across source folders. Pascal-case file modules keep the normal globally unique module behavior."
+    },
     "sources": {
       "$ref": "#/definitions/sources",
       "description": "Source code location"

rewatch/CompilerConfigurationSpec.md

@@ -7,6 +7,7 @@ This document contains a list of all config parameters with remarks, and whether
 | name                  | string                  |                                                             |     [x]      |
 | namespace             | boolean                 |                                                             |     [x]      |
 | namespace             | string                  |                                                             |     [x]      |
+| multi-entry           | boolean                 | Lowercase file modules stay private and duplicate lowercase file stems are allowed |     [x]      |
 | sources               | string                  |                                                             |     [x]      |
 | sources               | array of string         |                                                             |     [x]      |
 | sources               | Source                  |                                                             |     [x]      |

rewatch/src/build/clean.rs

@@ -250,7 +250,9 @@ pub fn cleanup_previous_build(
         .difference(&all_module_names)
         .flat_map(|module_name| {
             // if the module is a namespace, we need to mark the whole namespace as dirty when a module has been deleted
-            if let Some(namespace) = helpers::get_namespace_from_module_name(module_name) {
+            if !module_name.contains(':')
+                && let Some(namespace) = helpers::get_namespace_from_module_name(module_name)
+            {
                 return vec![namespace, module_name.to_string()];
             }
             vec![module_name.to_string()]

rewatch/src/build/compile.rs

@@ -523,10 +523,14 @@ pub fn compiler_args(
 ) -> Result<Vec<String>> {
     let bsc_flags = config::flatten_flags(&config.compiler_flags);
     let dependency_paths = get_dependency_paths(config, project_context, packages, is_type_dev);
-    let module_name = helpers::file_path_to_module_name(file_path, &config.get_namespace());
+    let multi_entry = config.is_multi_entry_enabled();
+    let module_name =
+        helpers::file_path_to_constructible_module_name(file_path, &config.get_namespace(), multi_entry);
 
     let namespace_args = match &config.get_namespace() {
-        packages::Namespace::NamespaceWithEntry { namespace: _, entry } if &module_name == entry => {
+        packages::Namespace::NamespaceWithEntry { namespace: _, entry }
+            if module_name.as_ref() == Some(entry) =>
+        {
             // if the module is the entry we just want to open the namespace
             vec![
                 "-open".to_string(),
@@ -567,12 +571,23 @@ pub fn compiler_args(
     };
 
     let package_name_arg = vec!["-bs-package-name".to_string(), config.name.to_owned()];
+    let multi_entry_arg = if multi_entry {
+        vec!["-bs-multi-entry".to_string()]
+    } else {
+        vec![]
+    };
 
     let implementation_args = if is_interface {
-        debug!("Compiling interface file: {}", &module_name);
+        debug!(
+            "Compiling interface file: {}",
+            module_name.as_deref().unwrap_or("<private file module>")
+        );
         vec![]
     } else {
-        debug!("Compiling file: {}", &module_name);
+        debug!(
+            "Compiling file: {}",
+            module_name.as_deref().unwrap_or("<private file module>")
+        );
         let specs = root_config.get_package_specs();
 
         specs
@@ -621,6 +636,7 @@ pub fn compiler_args(
         warning_args,
         gentype_arg,
         experimental_args,
+        multi_entry_arg,
         // vec!["-warn-error".to_string(), "A".to_string()],
         // ^^ this one fails for bisect-ppx
         // this is the default
@@ -751,6 +767,12 @@ fn compile_file(
     .map_err(|e| anyhow!(e))?;
     let basename =
         helpers::file_path_to_compiler_asset_basename(implementation_file_path, &package.namespace);
+    let is_constructible_module = helpers::file_path_to_constructible_module_name(
+        implementation_file_path,
+        &package.namespace,
+        package.config.is_multi_entry_enabled(),
+    )
+    .is_some();
     let has_interface = module.get_interface().is_some();
     let is_type_dev = module.is_type_dev;
     let to_mjs_args = compiler_args(
@@ -794,7 +816,7 @@ fn compile_file(
             let dir = Path::new(implementation_file_path).parent().unwrap();
 
             // perhaps we can do this copying somewhere else
-            if !is_interface {
+            if !is_interface && is_constructible_module {
                 let _ = std::fs::copy(
                     package
                         .get_build_path()
@@ -819,7 +841,7 @@ fn compile_file(
                         .join(format!("{basename}.cmt")),
                     ocaml_build_path_abs.join(format!("{basename}.cmt")),
                 );
-            } else {
+            } else if is_interface && is_constructible_module {
                 let _ = std::fs::copy(
                     package
                         .get_build_path()
@@ -847,13 +869,15 @@ fn compile_file(
                 )
                 .expect("copying source file failed");
 
-                let _ = std::fs::copy(
-                    Path::new(&package.path).join(path),
-                    package
-                        .get_ocaml_build_path()
-                        .join(std::path::Path::new(path).file_name().unwrap()),
-                )
-                .expect("copying source file failed");
+                if is_constructible_module {
+                    let _ = std::fs::copy(
+                        Path::new(&package.path).join(path),
+                        package
+                            .get_ocaml_build_path()
+                            .join(std::path::Path::new(path).file_name().unwrap()),
+                    )
+                    .expect("copying source file failed");
+                }
             }
             if let SourceType::SourceFile(SourceFile {
                 implementation: Implementation { path, .. },
@@ -869,13 +893,15 @@ fn compile_file(
                 )
                 .expect("copying source file failed");
 
-                let _ = std::fs::copy(
-                    Path::new(&package.path).join(path),
-                    package
-                        .get_ocaml_build_path()
-                        .join(std::path::Path::new(path).file_name().unwrap()),
-                )
-                .expect("copying source file failed");
+                if is_constructible_module {
+                    let _ = std::fs::copy(
+                        Path::new(&package.path).join(path),
+                        package
+                            .get_ocaml_build_path()
+                            .join(std::path::Path::new(path).file_name().unwrap()),
+                    )
+                    .expect("copying source file failed");
+                }
             }
 
             // copy js file