Add foundational emscripten functions and types to C API

lib/runtime-c-api/Cargo.toml

@@ -32,13 +32,19 @@ path = "../wasi"
 version = "0.11.0"
 optional = true
 
+[dependencies.wasmer-emscripten]
+path = "../emscripten"
+version = "0.11.0"
+optional = true
+
 [features]
 default = ["cranelift-backend", "wasi"]
 debug = ["wasmer-runtime/debug"]
 cranelift-backend = ["wasmer-runtime/cranelift", "wasmer-runtime/default-backend-cranelift"]
 llvm-backend = ["wasmer-runtime/llvm", "wasmer-runtime/default-backend-llvm"]
 singlepass-backend = ["wasmer-runtime/singlepass", "wasmer-runtime/default-backend-singlepass"]
 wasi = ["wasmer-wasi"]
+emscripten = ["wasmer-emscripten"]
 
 [build-dependencies]
 cbindgen = "0.9"

lib/runtime-c-api/build.rs

@@ -12,7 +12,7 @@ fn main() {
     let mut out_wasmer_header_file = PathBuf::from(&out_dir);
     out_wasmer_header_file.push("wasmer");
 
-    const WASMER_PRE_HEADER: &str = r#"
+    let mut pre_header = r#"
 #if !defined(WASMER_H_MACROS)
 #define WASMER_H_MACROS
 
@@ -28,17 +28,27 @@ fn main() {
 #endif
 #endif
 
-#endif // WASMER_H_MACROS
-"#;
+"#
+    .to_string();
+
+    #[cfg(feature = "emscripten")]
+    {
+        pre_header += "#define WASMER_EMSCRIPTEN_ENABLED\n";
+    }
+
+    // close pre header
+    pre_header += "#endif // WASMER_H_MACROS\n";
+
     // Generate the C bindings in the `OUT_DIR`.
     out_wasmer_header_file.set_extension("h");
     Builder::new()
         .with_crate(crate_dir.clone())
         .with_language(Language::C)
         .with_include_guard("WASMER_H")
-        .with_header(WASMER_PRE_HEADER)
+        .with_header(&pre_header)
         .with_define("target_family", "windows", "_WIN32")
         .with_define("target_arch", "x86_64", "ARCH_X86_64")
+        .with_define("feature", "emscripten", "WASMER_EMSCRIPTEN_ENABLED")
         .generate()
         .expect("Unable to generate C bindings")
         .write_to_file(out_wasmer_header_file.as_path());
@@ -49,9 +59,10 @@ fn main() {
         .with_crate(crate_dir)
         .with_language(Language::Cxx)
         .with_include_guard("WASMER_H")
-        .with_header(WASMER_PRE_HEADER)
+        .with_header(&pre_header)
         .with_define("target_family", "windows", "_WIN32")
         .with_define("target_arch", "x86_64", "ARCH_X86_64")
+        .with_define("feature", "emscripten", "WASMER_EMSCRIPTEN_ENABLED")
         .generate()
         .expect("Unable to generate C++ bindings")
         .write_to_file(out_wasmer_header_file.as_path());

lib/runtime-c-api/src/import/emscripten.rs

@@ -0,0 +1,58 @@
+//! Functions and types for dealing with Emscripten imports
+
+use super::*;
+use crate::module::wasmer_module_t;
+use std::ptr;
+use wasmer_emscripten::EmscriptenGlobals;
+use wasmer_runtime::Module;
+
+/// Type used to construct an import_object_t with Emscripten imports.
+#[repr(C)]
+pub struct wasmer_emscripten_globals_t;
+
+/// Create a `wasmer_emscripten_globals_t` from a Wasm module.
+#[no_mangle]
+pub unsafe extern "C" fn wasmer_emscripten_get_emscripten_globals(
+    module: *const wasmer_module_t,
+) -> *mut wasmer_emscripten_globals_t {
+    if module.is_null() {
+        return ptr::null_mut();
+    }
+    let module = &*(module as *const Module);
+    match EmscriptenGlobals::new(module) {
+        Ok(globals) => Box::into_raw(Box::new(globals)) as *mut wasmer_emscripten_globals_t,
+        Err(msg) => {
+            update_last_error(CApiError { msg });
+            return ptr::null_mut();
+        }
+    }
+}
+
+/// Destroy `wasmer_emscrpten_globals_t` created by
+/// `wasmer_emscripten_get_emscripten_globals`.
+#[no_mangle]
+pub unsafe extern "C" fn wasmer_emscripten_destroy_emscripten_globals(
+    globals: *mut wasmer_emscripten_globals_t,
+) {
+    if globals.is_null() {
+        return;
+    }
+    let _ = Box::from_raw(globals);
+}
+
+/// Create a `wasmer_import_object_t` with Emscripten imports, use
+/// `wasmer_emscripten_get_emscripten_globals` to get a
+/// `wasmer_emscripten_globals_t` from a `wasmer_module_t`.
+#[no_mangle]
+pub unsafe extern "C" fn wasmer_emscripten_generate_import_object(
+    globals: *mut wasmer_emscripten_globals_t,
+) -> *mut wasmer_import_object_t {
+    if globals.is_null() {
+        return ptr::null_mut();
+    }
+    // TODO: figure out if we should be using UnsafeCell here or something
+    let g = &mut *(globals as *mut EmscriptenGlobals);
+    let import_object = Box::new(wasmer_emscripten::generate_emscripten_env(g));
+
+    Box::into_raw(import_object) as *mut wasmer_import_object_t
+}

lib/runtime-c-api/src/import/mod.rs

@@ -61,6 +61,12 @@ mod wasi;
 #[cfg(feature = "wasi")]
 pub use self::wasi::*;
 
+#[cfg(feature = "emscripten")]
+mod emscripten;
+
+#[cfg(feature = "emscripten")]
+pub use self::emscripten::*;
+
 /// Gets an entry from an ImportObject at the name and namespace.
 /// Stores `name`, `namespace`, and `import_export_value` in `import`.
 /// Thus these must remain valid for the lifetime of `import`.
@@ -437,6 +443,9 @@ pub unsafe extern "C" fn wasmer_import_descriptors(
     module: *const wasmer_module_t,
     import_descriptors: *mut *mut wasmer_import_descriptors_t,
 ) {
+    if module.is_null() {
+        return;
+    }
     let module = &*(module as *const Module);
     let total_imports = module.info().imported_functions.len()
         + module.info().imported_tables.len()

lib/runtime-c-api/wasmer.h

@@ -74,6 +74,19 @@ typedef struct {
 
 } wasmer_module_t;
 
+#if defined(WASMER_EMSCRIPTEN_ENABLED)
+/**
+ * Type used to construct an import_object_t with Emscripten imports.
+ */
+typedef struct {
+
+} wasmer_emscripten_globals_t;
+#endif
+
+typedef struct {
+
+} wasmer_import_object_t;
+
 /**
  * Opaque pointer to `NamedExportDescriptor`.
  */
@@ -153,10 +166,6 @@ typedef struct {
 
 typedef struct {
 
-} wasmer_import_object_t;
-
-typedef struct {
-
 } wasmer_table_t;
 
 /**
@@ -247,6 +256,30 @@ wasmer_result_t wasmer_compile(wasmer_module_t **module,
                                uint8_t *wasm_bytes,
                                uint32_t wasm_bytes_len);
 
+#if defined(WASMER_EMSCRIPTEN_ENABLED)
+/**
+ * Destroy `wasmer_emscrpten_globals_t` created by
+ * `wasmer_emscripten_get_emscripten_globals`.
+ */
+void wasmer_emscripten_destroy_emscripten_globals(wasmer_emscripten_globals_t *globals);
+#endif
+
+#if defined(WASMER_EMSCRIPTEN_ENABLED)
+/**
+ * Create a `wasmer_import_object_t` with Emscripten imports, use
+ * `wasmer_emscripten_get_emscripten_globals` to get a
+ * `wasmer_emscripten_globals_t` from a `wasmer_module_t`.
+ */
+wasmer_import_object_t *wasmer_emscripten_generate_import_object(wasmer_emscripten_globals_t *globals);
+#endif
+
+#if defined(WASMER_EMSCRIPTEN_ENABLED)
+/**
+ * Create a `wasmer_emscripten_globals_t` from a Wasm module.
+ */
+wasmer_emscripten_globals_t *wasmer_emscripten_get_emscripten_globals(const wasmer_module_t *module);
+#endif
+
 /**
  * Gets export descriptor kind
  */

lib/runtime-c-api/wasmer.hh

@@ -61,6 +61,17 @@ struct wasmer_module_t {
 
 };
 
+#if defined(WASMER_EMSCRIPTEN_ENABLED)
+/// Type used to construct an import_object_t with Emscripten imports.
+struct wasmer_emscripten_globals_t {
+
+};
+#endif
+
+struct wasmer_import_object_t {
+
+};
+
 /// Opaque pointer to `NamedExportDescriptor`.
 struct wasmer_export_descriptor_t {
 
@@ -128,10 +139,6 @@ struct wasmer_import_func_t {
 
 };
 
-struct wasmer_import_object_t {
-
-};
-
 struct wasmer_table_t {
 
 };
@@ -216,6 +223,24 @@ wasmer_result_t wasmer_compile(wasmer_module_t **module,
                                uint8_t *wasm_bytes,
                                uint32_t wasm_bytes_len);
 
+#if defined(WASMER_EMSCRIPTEN_ENABLED)
+/// Destroy `wasmer_emscrpten_globals_t` created by
+/// `wasmer_emscripten_get_emscripten_globals`.
+void wasmer_emscripten_destroy_emscripten_globals(wasmer_emscripten_globals_t *globals);
+#endif
+
+#if defined(WASMER_EMSCRIPTEN_ENABLED)
+/// Create a `wasmer_import_object_t` with Emscripten imports, use
+/// `wasmer_emscripten_get_emscripten_globals` to get a
+/// `wasmer_emscripten_globals_t` from a `wasmer_module_t`.
+wasmer_import_object_t *wasmer_emscripten_generate_import_object(wasmer_emscripten_globals_t *globals);
+#endif
+
+#if defined(WASMER_EMSCRIPTEN_ENABLED)
+/// Create a `wasmer_emscripten_globals_t` from a Wasm module.
+wasmer_emscripten_globals_t *wasmer_emscripten_get_emscripten_globals(const wasmer_module_t *module);
+#endif
+
 /// Gets export descriptor kind
 wasmer_import_export_kind wasmer_export_descriptor_kind(wasmer_export_descriptor_t *export_);