Merge #1030

1030: feat(runtime-c-api) Ability to generate `ImportObject` for a specific WASI version r=Hywan a=Hywan ❗️⚠️ Contains #1028, must be merged before this one. This patch introduces 2 new functions: * `wasmer_wasi_generate_import_object_for_version` and * `wasmer_wasi_get_version`. It mimics the current API provided by `wasmer_wasi`, nothing fancy here. It's just a regular port to C/C++. Because `wasmer_wasi::get_wasi_version` returns an option, and in order to simplify the C/C++ API, `wasmer_wasi_get_version` can return `Version::Unknown` in case of an error. It's up to the user to check the version is valid (i.e. not unknown). To see only the changes provided by this PR (excluding #1028), check Hywan/wasmer@fix-wasi-get-version...feat-runtime-c-api-wasi-version. Co-authored-by: Ivan Enderlin <[email protected]>
wasmerio · Dec 6, 2019 · 59d2b8b · 59d2b8b
2 parents ee16823 + 45e4081
commit 59d2b8b
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -2,6 +2,7 @@
 
 ## **[Unreleased]**
 
+- [#1030](https://github.com/wasmerio/wasmer/pull/1030) Ability to generate `ImportObject` for a specific version WASI version with the C API.
 - [#1028](https://github.com/wasmerio/wasmer/pull/1028) Introduce strict/non-strict modes for `get_wasi_version`
 - [#1029](https://github.com/wasmerio/wasmer/pull/1029) Add the “floating” `WasiVersion::Latest` version.
 - [#1006](https://github.com/wasmerio/wasmer/pull/1006) Fix minor panic issue when `wasmer::compile_with` called with llvm backend

diff --git a/lib/runtime-c-api/README.md b/lib/runtime-c-api/README.md
@@ -112,7 +112,7 @@ rebuild in release mode for the tests to see the changes.
 The tests can be run via `cargo test`, such as:
 
 ```sh
-$ cargo test -- --nocapture
+$ cargo test --release -- --nocapture
 ```
 
 To run tests manually, enter the `lib/runtime-c-api/tests` directory

diff --git a/lib/runtime-c-api/src/import/mod.rs b/lib/runtime-c-api/src/import/mod.rs
@@ -8,7 +8,7 @@ use crate::{
     value::wasmer_value_tag,
     wasmer_byte_array, wasmer_result_t,
 };
-use libc::c_uint;
+use libc::{c_uchar, c_uint};
 use std::{convert::TryFrom, ffi::c_void, ptr, slice, sync::Arc};
 use wasmer_runtime::{Global, Memory, Module, Table};
 use wasmer_runtime_core::{

diff --git a/lib/runtime-c-api/src/import/wasi.rs b/lib/runtime-c-api/src/import/wasi.rs
@@ -1,6 +1,35 @@
 use super::*;
 use crate::get_slice_checked;
-use std::path::PathBuf;
+use std::{path::PathBuf, ptr, str};
+use wasmer_wasi as wasi;
+
+#[derive(Debug, PartialEq)]
+#[repr(u8)]
+pub enum Version {
+    /// Version cannot be detected or is unknown.
+    Unknown = 0,
+
+    /// Latest version. See `wasmer_wasi::WasiVersion::Latest` to
+    /// leran more.
+    Latest = 1,
+
+    /// `wasi_unstable`.
+    Snapshot0 = 2,
+
+    /// `wasi_snapshot_preview1`.
+    Snapshot1 = 3,
+}
+
+impl From<c_uchar> for Version {
+    fn from(value: c_uchar) -> Self {
+        match value {
+            1 => Self::Latest,
+            2 => Self::Snapshot0,
+            3 => Self::Snapshot1,
+            _ => Self::Unknown,
+        }
+    }
+}
 
 /// Opens a directory that's visible to the WASI module as `alias` but
 /// is backed by the host file at `host_file_path`
@@ -14,9 +43,9 @@ pub struct wasmer_wasi_map_dir_entry_t {
 
 impl wasmer_wasi_map_dir_entry_t {
     /// Converts the data into owned, Rust types
-    pub unsafe fn as_tuple(&self) -> Result<(String, PathBuf), std::str::Utf8Error> {
+    pub unsafe fn as_tuple(&self) -> Result<(String, PathBuf), str::Utf8Error> {
         let alias = self.alias.as_str()?.to_owned();
-        let host_path = std::path::PathBuf::from(self.host_file_path.as_str()?);
+        let host_path = PathBuf::from(self.host_file_path.as_str()?);
 
         Ok((alias, host_path))
     }
@@ -44,21 +73,77 @@ pub unsafe extern "C" fn wasmer_wasi_generate_import_object(
     let mapped_dir_list = get_slice_checked(mapped_dirs, mapped_dirs_len as usize);
 
     wasmer_wasi_generate_import_object_inner(
+        Version::Latest,
         arg_list,
         env_list,
         preopened_file_list,
         mapped_dir_list,
     )
-    .unwrap_or(std::ptr::null_mut())
+    .unwrap_or(ptr::null_mut())
+}
+
+/// Creates a WASI import object for a specific version.
+///
+/// This function is similar to `wasmer_wasi_generate_import_object`
+/// except that the first argument describes the WASI version.
+///
+/// The version is expected to be of kind `Version`.
+#[no_mangle]
+pub unsafe extern "C" fn wasmer_wasi_generate_import_object_for_version(
+    version: c_uchar,
+    args: *const wasmer_byte_array,
+    args_len: c_uint,
+    envs: *const wasmer_byte_array,
+    envs_len: c_uint,
+    preopened_files: *const wasmer_byte_array,
+    preopened_files_len: c_uint,
+    mapped_dirs: *const wasmer_wasi_map_dir_entry_t,
+    mapped_dirs_len: c_uint,
+) -> *mut wasmer_import_object_t {
+    let arg_list = get_slice_checked(args, args_len as usize);
+    let env_list = get_slice_checked(envs, envs_len as usize);
+    let preopened_file_list = get_slice_checked(preopened_files, preopened_files_len as usize);
+    let mapped_dir_list = get_slice_checked(mapped_dirs, mapped_dirs_len as usize);
+
+    wasmer_wasi_generate_import_object_inner(
+        version.into(),
+        arg_list,
+        env_list,
+        preopened_file_list,
+        mapped_dir_list,
+    )
+    .unwrap_or(ptr::null_mut())
+}
+
+/// Find the version of WASI used by the module.
+///
+/// In case of error, the returned version is `Version::Unknown`.
+#[no_mangle]
+pub unsafe extern "C" fn wasmer_wasi_get_version(module: *const wasmer_module_t) -> Version {
+    if module.is_null() {
+        return Version::Unknown;
+    }
+
+    let module = &*(module as *const Module);
+
+    match wasi::get_wasi_version(module, false) {
+        Some(version) => match version {
+            wasi::WasiVersion::Snapshot0 => Version::Snapshot0,
+            wasi::WasiVersion::Snapshot1 => Version::Snapshot1,
+            wasi::WasiVersion::Latest => Version::Latest,
+        },
+        None => Version::Unknown,
+    }
 }
 
 /// Inner function that wraps error handling
 fn wasmer_wasi_generate_import_object_inner(
+    version: Version,
     arg_list: &[wasmer_byte_array],
     env_list: &[wasmer_byte_array],
     preopened_file_list: &[wasmer_byte_array],
     mapped_dir_list: &[wasmer_wasi_map_dir_entry_t],
-) -> Result<*mut wasmer_import_object_t, std::str::Utf8Error> {
+) -> Result<*mut wasmer_import_object_t, str::Utf8Error> {
     let arg_vec = arg_list.iter().map(|arg| unsafe { arg.as_vec() }).collect();
     let env_vec = env_list
         .iter()
@@ -73,7 +158,15 @@ fn wasmer_wasi_generate_import_object_inner(
         .map(|entry| unsafe { entry.as_tuple() })
         .collect::<Result<Vec<_>, _>>()?;
 
-    let import_object = Box::new(wasmer_wasi::generate_import_object(
+    let version = match version {
+        Version::Latest => wasi::WasiVersion::Latest,
+        Version::Snapshot0 => wasi::WasiVersion::Snapshot0,
+        Version::Snapshot1 => wasi::WasiVersion::Snapshot1,
+        _ => panic!("Version {:?} is invalid.", version),
+    };
+
+    let import_object = Box::new(wasi::generate_import_object_for_version(
+        version,
         arg_vec,
         env_vec,
         po_file_vec,
@@ -90,12 +183,20 @@ fn wasmer_wasi_generate_import_object_inner(
 #[no_mangle]
 pub unsafe extern "C" fn wasmer_wasi_generate_default_import_object() -> *mut wasmer_import_object_t
 {
-    let import_object = Box::new(wasmer_wasi::generate_import_object(
-        vec![],
-        vec![],
-        vec![],
-        vec![],
-    ));
+    let import_object = Box::new(wasi::generate_import_object(vec![], vec![], vec![], vec![]));
 
     Box::into_raw(import_object) as *mut wasmer_import_object_t
 }
+
+#[cfg(test)]
+mod tests {
+    use super::Version;
+
+    #[test]
+    fn test_versions_from_uint() {
+        assert_eq!(Version::Unknown, 0.into());
+        assert_eq!(Version::Latest, 1.into());
+        assert_eq!(Version::Snapshot0, 2.into());
+        assert_eq!(Version::Snapshot1, 3.into());
+    }
+}
diff --git a/lib/runtime-c-api/tests/.gitignore b/lib/runtime-c-api/tests/.gitignore
@@ -10,20 +10,20 @@ compile_commands.json
 CTestTestfile.cmake
 _deps
 rust-build
+test-context
 test-exported-memory
 test-exports
 test-globals
 test-import-function
+test-import-object
 test-imports
 test-instantiate
 test-memory
 test-module
 test-module-exports
+test-module-import-instantiate
 test-module-imports
 test-module-serialize
 test-tables
 test-validate
-test-context
-test-module-import-instantiate
-test-wasi-import-object
-
+test-wasi-import-object
diff --git a/lib/runtime-c-api/tests/CMakeLists.txt b/lib/runtime-c-api/tests/CMakeLists.txt
@@ -19,12 +19,12 @@ add_executable(test-context test-context.c)
 add_executable(test-module-import-instantiate test-module-import-instantiate.c)
 
 if (DEFINED WASI_TESTS)
-   add_executable(test-wasi-import-object test-wasi-import-object.c)
+    add_executable(test-wasi-import-object test-wasi-import-object.c)
 endif()
 
 find_library(
-        WASMER_LIB NAMES libwasmer_runtime_c_api.dylib libwasmer_runtime_c_api.so wasmer_runtime_c_api.dll
-        PATHS ${CMAKE_SOURCE_DIR}/../../../target/release/
+    WASMER_LIB NAMES libwasmer_runtime_c_api.dylib libwasmer_runtime_c_api.so wasmer_runtime_c_api.dll
+    PATHS ${CMAKE_SOURCE_DIR}/../../../target/release/
 )
 
 if(NOT WASMER_LIB)

diff --git a/lib/runtime-c-api/tests/test-wasi-import-object.c b/lib/runtime-c-api/tests/test-wasi-import-object.c
@@ -28,9 +28,9 @@ void print_wasmer_error()
 
 // helper function to print byte array to stdout
 void print_byte_array(wasmer_byte_array *arr) {
-        for (int i = 0; i < arr->bytes_len; ++i) {
-                putchar(arr->bytes[i]);
-        }
+    for (int i = 0; i < arr->bytes_len; ++i) {
+        putchar(arr->bytes[i]);
+    }
 }
 
 int main()
@@ -164,20 +164,7 @@ int main()
     };
     int mapped_dir_len = sizeof(mapped_dirs) / sizeof(mapped_dirs[0]);
 
-    // Create the WASI import object
-    wasmer_import_object_t *import_object =
-            wasmer_wasi_generate_import_object(args, wasi_argc,
-                                               envs, wasi_env_len,
-                                               NULL, 0,
-                                               mapped_dirs, mapped_dir_len);
-
-    // Create our imports
-    wasmer_import_t imports[] = {func_import, global_import, memory_import, table_import};
-    int imports_len = sizeof(imports) / sizeof(imports[0]);
-    // Add our imports to the import object
-    wasmer_import_object_extend(import_object, imports, imports_len);
-
-    // Read the wasm file bytes
+    // Read the Wasm file bytes.
     FILE *file = fopen("assets/extended_wasi.wasm", "r");
     assert(file);
     fseek(file, 0, SEEK_END);
@@ -191,16 +178,39 @@ int main()
     // Compile the WebAssembly module
     wasmer_result_t compile_result = wasmer_compile(&module, bytes, len);
     printf("Compile result:  %d\n", compile_result);
+
     if (compile_result != WASMER_OK)
     {
         print_wasmer_error();
     }
+
     assert(compile_result == WASMER_OK);
 
+    // Detect the WASI version if any. This step is not mandatory, we
+    // use it to test the WASI version API.
+    Version wasi_version = wasmer_wasi_get_version(module);
+
+    printf("WASI version:    %d\n", wasi_version);
+
+    // Create the WASI import object
+    wasmer_import_object_t *import_object =
+        wasmer_wasi_generate_import_object_for_version(wasi_version,
+                                                       args, wasi_argc,
+                                                       envs, wasi_env_len,
+                                                       NULL, 0,
+                                                       mapped_dirs, mapped_dir_len);
+
+    // Create our imports
+    wasmer_import_t imports[] = {func_import, global_import, memory_import, table_import};
+    int imports_len = sizeof(imports) / sizeof(imports[0]);
+    // Add our imports to the import object
+    wasmer_import_object_extend(import_object, imports, imports_len);
+
     // Instantiatoe the module with our import_object
     wasmer_instance_t *instance = NULL;
     wasmer_result_t instantiate_result = wasmer_module_import_instantiate(&instance, module, import_object);
     printf("Instantiate result:  %d\n", instantiate_result);
+
     if (instantiate_result != WASMER_OK)
     {
         print_wasmer_error();

diff --git a/lib/runtime-c-api/wasmer.h b/lib/runtime-c-api/wasmer.h
@@ -25,6 +25,27 @@
 #include <stdint.h>
 #include <stdlib.h>
 
+enum Version {
+  /**
+   * Version cannot be detected or is unknown.
+   */
+  Unknown = 0,
+  /**
+   * Latest version. See `wasmer_wasi::WasiVersion::Latest` to
+   * leran more.
+   */
+  Latest = 1,
+  /**
+   * `wasi_unstable`.
+   */
+  Snapshot0 = 2,
+  /**
+   * `wasi_snapshot_preview1`.
+   */
+  Snapshot1 = 3,
+};
+typedef uint8_t Version;
+
 /**
  * List of export/import kinds.
  */
@@ -890,4 +911,29 @@ wasmer_import_object_t *wasmer_wasi_generate_import_object(const wasmer_byte_arr
                                                            const wasmer_wasi_map_dir_entry_t *mapped_dirs,
                                                            unsigned int mapped_dirs_len);
 
+/**
+ * Creates a WASI import object for a specific version.
+ *
+ * This function is similar to `wasmer_wasi_generate_import_object`
+ * except that the first argument describes the WASI version.
+ *
+ * The version is expected to be of kind `Version`.
+ */
+wasmer_import_object_t *wasmer_wasi_generate_import_object_for_version(unsigned char version,
+                                                                       const wasmer_byte_array *args,
+                                                                       unsigned int args_len,
+                                                                       const wasmer_byte_array *envs,
+                                                                       unsigned int envs_len,
+                                                                       const wasmer_byte_array *preopened_files,
+                                                                       unsigned int preopened_files_len,
+                                                                       const wasmer_wasi_map_dir_entry_t *mapped_dirs,
+                                                                       unsigned int mapped_dirs_len);
+
+/**
+ * Find the version of WASI used by the module.
+ *
+ * In case of error, the returned version is `Version::Unknown`.
+ */
+Version wasmer_wasi_get_version(const wasmer_module_t *module);
+
 #endif /* WASMER_H */