From fdc3d5107aa100074645da72b8431042dbbe594d Mon Sep 17 00:00:00 2001
From: Ivan Enderlin <ivan.enderlin@hoa-project.net>
Date: Mon, 2 Dec 2019 15:58:23 +0100
Subject: [PATCH 01/15] doc(runtime-c-api) Suggest to test in release mode.

---
 lib/runtime-c-api/README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/runtime-c-api/README.md b/lib/runtime-c-api/README.md
index 06e545bf739..39e2c21a9fa 100644
--- 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

From ca4a1b41a66fbfbcd5466826a47a19e8aab74369 Mon Sep 17 00:00:00 2001
From: Ivan Enderlin <ivan.enderlin@hoa-project.net>
Date: Mon, 2 Dec 2019 15:59:20 +0100
Subject: [PATCH 02/15] feat(runtime-c-api) Ability to generate `ImportObject`
 for a specific WASI version.

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).
---
 lib/runtime-c-api/src/import/wasi.rs | 91 ++++++++++++++++++++++++----
 1 file changed, 79 insertions(+), 12 deletions(-)

diff --git a/lib/runtime-c-api/src/import/wasi.rs b/lib/runtime-c-api/src/import/wasi.rs
index 3df3c7f700b..ec362fdf2ec 100644
--- a/lib/runtime-c-api/src/import/wasi.rs
+++ b/lib/runtime-c-api/src/import/wasi.rs
@@ -1,6 +1,18 @@
 use super::*;
 use crate::get_slice_checked;
-use std::path::PathBuf;
+use std::{path::PathBuf, ptr, str};
+use wasmer_wasi as wasi;
+
+#[derive(Debug)]
+#[repr(u8)]
+pub enum Version {
+    /// Version cannot be detected or is unknown.
+    Unknown,
+    /// `wasi_unstable`.
+    Snapshot0,
+    /// `wasi_snapshot_preview1`.
+    Snapshot1,
+}
 
 /// 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 +26,9 @@ 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 +56,74 @@ 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::Snapshot1,
         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.
+///
+/// This function is similar to `wasmer_wasi_generate_import_object`
+/// except that the first argument describes the WASI version.
+#[no_mangle]
+pub unsafe extern "C" fn wasmer_wasi_generate_import_object_for_version(
+    version: Version,
+    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,
+        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) {
+        Some(version) => match version {
+            wasi::WasiVersion::Snapshot0 => Version::Snapshot0,
+            wasi::WasiVersion::Snapshot1 => Version::Snapshot1,
+        },
+        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 +138,14 @@ 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::Snapshot0 => wasi::WasiVersion::Snapshot0,
+        Version::Snapshot1 => wasi::WasiVersion::Snapshot1,
+        _ => panic!(format!("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 +162,7 @@ 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
 }

From e2c353b926ad4e46a8b3a10289188ca021501255 Mon Sep 17 00:00:00 2001
From: Ivan Enderlin <ivan.enderlin@hoa-project.net>
Date: Mon, 2 Dec 2019 16:05:01 +0100
Subject: [PATCH 03/15] chore(runtime-c-api) Update C/C++ headers.

---
 lib/runtime-c-api/wasmer.h  | 39 +++++++++++++++++++++++++++++++++++++
 lib/runtime-c-api/wasmer.hh | 28 ++++++++++++++++++++++++++
 2 files changed, 67 insertions(+)

diff --git a/lib/runtime-c-api/wasmer.h b/lib/runtime-c-api/wasmer.h
index 40a265cff3b..672a1704cd5 100644
--- a/lib/runtime-c-api/wasmer.h
+++ b/lib/runtime-c-api/wasmer.h
@@ -25,6 +25,22 @@
 #include <stdint.h>
 #include <stdlib.h>
 
+enum Version {
+  /**
+   * Version cannot be detected or is unknown.
+   */
+  Unknown,
+  /**
+   * `wasi_unstable`.
+   */
+  Snapshot0,
+  /**
+   * `wasi_snapshot_preview1`.
+   */
+  Snapshot1,
+};
+typedef uint8_t Version;
+
 /**
  * List of export/import kinds.
  */
@@ -890,4 +906,27 @@ 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.
+ *
+ * This function is similar to `wasmer_wasi_generate_import_object`
+ * except that the first argument describes the WASI version.
+ */
+wasmer_import_object_t *wasmer_wasi_generate_import_object_for_version(Version 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 */
diff --git a/lib/runtime-c-api/wasmer.hh b/lib/runtime-c-api/wasmer.hh
index b437edd4be0..d293c817ebc 100644
--- a/lib/runtime-c-api/wasmer.hh
+++ b/lib/runtime-c-api/wasmer.hh
@@ -25,6 +25,15 @@
 #include <cstdlib>
 #include <new>
 
+enum class Version : uint8_t {
+  /// Version cannot be detected or is unknown.
+  Unknown,
+  /// `wasi_unstable`.
+  Snapshot0,
+  /// `wasi_snapshot_preview1`.
+  Snapshot1,
+};
+
 /// List of export/import kinds.
 enum class wasmer_import_export_kind : uint32_t {
   WASM_FUNCTION = 0,
@@ -702,6 +711,25 @@ 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.
+///
+/// This function is similar to `wasmer_wasi_generate_import_object`
+/// except that the first argument describes the WASI version.
+wasmer_import_object_t *wasmer_wasi_generate_import_object_for_version(Version 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);
+
 } // extern "C"
 
 #endif // WASMER_H

From 7fb934f5d09452935d4e9628a5b634e8ad6f03c5 Mon Sep 17 00:00:00 2001
From: Ivan Enderlin <ivan.enderlin@hoa-project.net>
Date: Mon, 2 Dec 2019 16:05:34 +0100
Subject: [PATCH 04/15] chore(runtime-c-api) Fix CS in `CMakeLists.txt`.

---
 lib/runtime-c-api/tests/CMakeLists.txt | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/runtime-c-api/tests/CMakeLists.txt b/lib/runtime-c-api/tests/CMakeLists.txt
index e4a573e6386..20f7dea13bd 100644
--- 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)

From 0391ade76f0d1a7abd8099279154ecc256a320a1 Mon Sep 17 00:00:00 2001
From: Ivan Enderlin <ivan.enderlin@hoa-project.net>
Date: Mon, 2 Dec 2019 16:07:20 +0100
Subject: [PATCH 05/15] chore(git) Ignore the object file `test-import-object`.

---
 lib/runtime-c-api/tests/.gitignore | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/lib/runtime-c-api/tests/.gitignore b/lib/runtime-c-api/tests/.gitignore
index b64fa610c7e..cbc7f3b1fcf 100644
--- 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
\ No newline at end of file

From 912713f88fc51122627a65f05cfbdb0566f9e218 Mon Sep 17 00:00:00 2001
From: Ivan Enderlin <ivan.enderlin@hoa-project.net>
Date: Mon, 2 Dec 2019 16:09:14 +0100
Subject: [PATCH 06/15] test(runtime-c-api) Test the new WASI version API.

This patch updates `test-wasi-import-object` to test the new
`wasmer_wasi_get_version` &
`wasmer_wasi_generate_import_object_for_version` functions, and the
new `Version` type.
---
 .../tests/test-wasi-import-object.c           | 44 ++++++++++++-------
 1 file changed, 27 insertions(+), 17 deletions(-)

diff --git a/lib/runtime-c-api/tests/test-wasi-import-object.c b/lib/runtime-c-api/tests/test-wasi-import-object.c
index bd1478dc137..da94849963e 100644
--- 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();

From b9851f26d45de4a0e9fd9c8af43716257c76a9f5 Mon Sep 17 00:00:00 2001
From: Ivan Enderlin <ivan.enderlin@hoa-project.net>
Date: Mon, 2 Dec 2019 16:19:19 +0100
Subject: [PATCH 07/15] doc(changelog) Add #1030.

---
 CHANGELOG.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 266dd165d34..b339615c989 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,8 @@
 
 - [#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.
+- [#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) Fix `get_wasi_version` when a module has multiple import namespaces.
 - [#1006](https://github.com/wasmerio/wasmer/pull/1006) Fix minor panic issue when `wasmer::compile_with` called with llvm backend
 - [#1009](https://github.com/wasmerio/wasmer/pull/1009) Enable LLVM verifier for all tests, add new llvm-backend-tests crate.
 - [#1022](https://github.com/wasmerio/wasmer/pull/1022) Add caching support for Singlepass backend.

From 4fe8286b8197ebc4174553343aebae1930241157 Mon Sep 17 00:00:00 2001
From: Ivan Enderlin <ivan.enderlin@hoa-project.net>
Date: Wed, 4 Dec 2019 14:33:10 +0100
Subject: [PATCH 08/15] feat(runtime-c-api) Avoid undefined behavior with
 user-given version.
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

When the version has type `Version`, we expect the user to give a
valid `Version` variant. Since the `Version` is basically a `uint8_t`,
the user is able to pass everything she wants, which can create an
undefined behavior on the Rust side.

To avoid such situation, the version has now type `c_uchar` (`unsigned
char` or `uint8_t` on C side —on most platforms). Then the `From`
trait is implemented on `Version`. In case the value is unbound,
`Version::Unknown` is returned.
---
 lib/runtime-c-api/src/import/mod.rs  |  2 +-
 lib/runtime-c-api/src/import/wasi.rs | 14 ++++++++++++--
 lib/runtime-c-api/wasmer.h           |  2 +-
 lib/runtime-c-api/wasmer.hh          |  2 +-
 4 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/lib/runtime-c-api/src/import/mod.rs b/lib/runtime-c-api/src/import/mod.rs
index 5b44eb2b557..2bca1e3902c 100644
--- 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
index ec362fdf2ec..2f105b1a1d3 100644
--- a/lib/runtime-c-api/src/import/wasi.rs
+++ b/lib/runtime-c-api/src/import/wasi.rs
@@ -14,6 +14,16 @@ pub enum Version {
     Snapshot1,
 }
 
+impl From<c_uchar> for Version {
+    fn from(value: c_uchar) -> Self {
+        match value {
+            0 => Self::Snapshot0,
+            1 => 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`
 #[repr(C)]
@@ -71,7 +81,7 @@ pub unsafe extern "C" fn wasmer_wasi_generate_import_object(
 /// except that the first argument describes the WASI version.
 #[no_mangle]
 pub unsafe extern "C" fn wasmer_wasi_generate_import_object_for_version(
-    version: Version,
+    version: c_uchar,
     args: *const wasmer_byte_array,
     args_len: c_uint,
     envs: *const wasmer_byte_array,
@@ -87,7 +97,7 @@ pub unsafe extern "C" fn wasmer_wasi_generate_import_object_for_version(
     let mapped_dir_list = get_slice_checked(mapped_dirs, mapped_dirs_len as usize);
 
     wasmer_wasi_generate_import_object_inner(
-        version,
+        version.into(),
         arg_list,
         env_list,
         preopened_file_list,
diff --git a/lib/runtime-c-api/wasmer.h b/lib/runtime-c-api/wasmer.h
index 672a1704cd5..09d716e8ab5 100644
--- a/lib/runtime-c-api/wasmer.h
+++ b/lib/runtime-c-api/wasmer.h
@@ -912,7 +912,7 @@ wasmer_import_object_t *wasmer_wasi_generate_import_object(const wasmer_byte_arr
  * This function is similar to `wasmer_wasi_generate_import_object`
  * except that the first argument describes the WASI version.
  */
-wasmer_import_object_t *wasmer_wasi_generate_import_object_for_version(Version 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,
diff --git a/lib/runtime-c-api/wasmer.hh b/lib/runtime-c-api/wasmer.hh
index d293c817ebc..aac8daec312 100644
--- a/lib/runtime-c-api/wasmer.hh
+++ b/lib/runtime-c-api/wasmer.hh
@@ -715,7 +715,7 @@ wasmer_import_object_t *wasmer_wasi_generate_import_object(const wasmer_byte_arr
 ///
 /// This function is similar to `wasmer_wasi_generate_import_object`
 /// except that the first argument describes the WASI version.
-wasmer_import_object_t *wasmer_wasi_generate_import_object_for_version(Version 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,

From 0c5021484f680db913689bf6a720040fe319c32f Mon Sep 17 00:00:00 2001
From: Ivan Enderlin <ivan.enderlin@hoa-project.net>
Date: Wed, 4 Dec 2019 14:37:13 +0100
Subject: [PATCH 09/15] fix(runtime-c-api) Use `get_wasi_version` in non-strict
 mode.

---
 lib/runtime-c-api/src/import/wasi.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/runtime-c-api/src/import/wasi.rs b/lib/runtime-c-api/src/import/wasi.rs
index 2f105b1a1d3..9b63a96a1f6 100644
--- a/lib/runtime-c-api/src/import/wasi.rs
+++ b/lib/runtime-c-api/src/import/wasi.rs
@@ -117,7 +117,7 @@ pub unsafe extern "C" fn wasmer_wasi_get_version(module: *const wasmer_module_t)
 
     let module = &*(module as *const Module);
 
-    match wasi::get_wasi_version(module) {
+    match wasi::get_wasi_version(module, false) {
         Some(version) => match version {
             wasi::WasiVersion::Snapshot0 => Version::Snapshot0,
             wasi::WasiVersion::Snapshot1 => Version::Snapshot1,

From 90f3c894c110cbe27c69494ac8c64347ae19fa14 Mon Sep 17 00:00:00 2001
From: Ivan Enderlin <ivan.enderlin@hoa-project.net>
Date: Wed, 4 Dec 2019 14:38:54 +0100
Subject: [PATCH 10/15] doc(runtime-c-api) Improve documentation of
 `wasmer_wasi_generate_import_object_for_version`.

---
 lib/runtime-c-api/src/import/wasi.rs | 4 +++-
 lib/runtime-c-api/wasmer.h           | 4 +++-
 lib/runtime-c-api/wasmer.hh          | 4 +++-
 3 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/lib/runtime-c-api/src/import/wasi.rs b/lib/runtime-c-api/src/import/wasi.rs
index 9b63a96a1f6..46caab24880 100644
--- a/lib/runtime-c-api/src/import/wasi.rs
+++ b/lib/runtime-c-api/src/import/wasi.rs
@@ -75,10 +75,12 @@ pub unsafe extern "C" fn wasmer_wasi_generate_import_object(
     .unwrap_or(ptr::null_mut())
 }
 
-/// Creates a WASI import object.
+/// 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,
diff --git a/lib/runtime-c-api/wasmer.h b/lib/runtime-c-api/wasmer.h
index 09d716e8ab5..282a6ee05d4 100644
--- a/lib/runtime-c-api/wasmer.h
+++ b/lib/runtime-c-api/wasmer.h
@@ -907,10 +907,12 @@ wasmer_import_object_t *wasmer_wasi_generate_import_object(const wasmer_byte_arr
                                                            unsigned int mapped_dirs_len);
 
 /**
- * Creates a WASI import object.
+ * 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,
diff --git a/lib/runtime-c-api/wasmer.hh b/lib/runtime-c-api/wasmer.hh
index aac8daec312..a78780118d0 100644
--- a/lib/runtime-c-api/wasmer.hh
+++ b/lib/runtime-c-api/wasmer.hh
@@ -711,10 +711,12 @@ 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.
+/// 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,

From 345511a4f9800e63611ec8ffbac3fa08c73884b2 Mon Sep 17 00:00:00 2001
From: Ivan Enderlin <ivan.enderlin@hoa-project.net>
Date: Wed, 4 Dec 2019 14:48:12 +0100
Subject: [PATCH 11/15] fix(runtime-c-api) Fix `From<c_uchar> for Version`.

0 matches to `Unknown`, 1 matches to `Snapshot0` and 2 matches to
`Snapshot1`.
---
 lib/runtime-c-api/src/import/wasi.rs | 24 ++++++++++++++++++------
 lib/runtime-c-api/wasmer.h           |  6 +++---
 lib/runtime-c-api/wasmer.hh          |  6 +++---
 3 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/lib/runtime-c-api/src/import/wasi.rs b/lib/runtime-c-api/src/import/wasi.rs
index 46caab24880..2766cb83cba 100644
--- a/lib/runtime-c-api/src/import/wasi.rs
+++ b/lib/runtime-c-api/src/import/wasi.rs
@@ -3,22 +3,22 @@ use crate::get_slice_checked;
 use std::{path::PathBuf, ptr, str};
 use wasmer_wasi as wasi;
 
-#[derive(Debug)]
+#[derive(Debug, PartialEq)]
 #[repr(u8)]
 pub enum Version {
     /// Version cannot be detected or is unknown.
-    Unknown,
+    Unknown = 0,
     /// `wasi_unstable`.
-    Snapshot0,
+    Snapshot0 = 1,
     /// `wasi_snapshot_preview1`.
-    Snapshot1,
+    Snapshot1 = 2,
 }
 
 impl From<c_uchar> for Version {
     fn from(value: c_uchar) -> Self {
         match value {
-            0 => Self::Snapshot0,
-            1 => Self::Snapshot1,
+            1 => Self::Snapshot0,
+            2 => Self::Snapshot1,
             _ => Self::Unknown,
         }
     }
@@ -178,3 +178,15 @@ pub unsafe extern "C" fn wasmer_wasi_generate_default_import_object() -> *mut wa
 
     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::Snapshot0, 1.into());
+        assert_eq!(Version::Snapshot1, 2.into());
+    }
+}
diff --git a/lib/runtime-c-api/wasmer.h b/lib/runtime-c-api/wasmer.h
index 282a6ee05d4..1440b16dcd9 100644
--- a/lib/runtime-c-api/wasmer.h
+++ b/lib/runtime-c-api/wasmer.h
@@ -29,15 +29,15 @@ enum Version {
   /**
    * Version cannot be detected or is unknown.
    */
-  Unknown,
+  Unknown = 0,
   /**
    * `wasi_unstable`.
    */
-  Snapshot0,
+  Snapshot0 = 1,
   /**
    * `wasi_snapshot_preview1`.
    */
-  Snapshot1,
+  Snapshot1 = 2,
 };
 typedef uint8_t Version;
 
diff --git a/lib/runtime-c-api/wasmer.hh b/lib/runtime-c-api/wasmer.hh
index a78780118d0..5366ee88d41 100644
--- a/lib/runtime-c-api/wasmer.hh
+++ b/lib/runtime-c-api/wasmer.hh
@@ -27,11 +27,11 @@
 
 enum class Version : uint8_t {
   /// Version cannot be detected or is unknown.
-  Unknown,
+  Unknown = 0,
   /// `wasi_unstable`.
-  Snapshot0,
+  Snapshot0 = 1,
   /// `wasi_snapshot_preview1`.
-  Snapshot1,
+  Snapshot1 = 2,
 };
 
 /// List of export/import kinds.

From 4fc6adf9c28bd387fe7f394a0cae3b1d0d303106 Mon Sep 17 00:00:00 2001
From: Ivan Enderlin <ivan.enderlin@hoa-project.net>
Date: Wed, 4 Dec 2019 14:51:29 +0100
Subject: [PATCH 12/15] chore(runtime-c-api) Remove a useless `format!`.

---
 lib/runtime-c-api/src/import/wasi.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/runtime-c-api/src/import/wasi.rs b/lib/runtime-c-api/src/import/wasi.rs
index 2766cb83cba..6d7e6a52352 100644
--- a/lib/runtime-c-api/src/import/wasi.rs
+++ b/lib/runtime-c-api/src/import/wasi.rs
@@ -153,7 +153,7 @@ fn wasmer_wasi_generate_import_object_inner(
     let version = match version {
         Version::Snapshot0 => wasi::WasiVersion::Snapshot0,
         Version::Snapshot1 => wasi::WasiVersion::Snapshot1,
-        _ => panic!(format!("Version {:?} is invalid.", version)),
+        _ => panic!("Version {:?} is invalid.", version),
     };
 
     let import_object = Box::new(wasi::generate_import_object_for_version(

From f0f0657264bfce83d7ffc17ab7884a3ba1c511aa Mon Sep 17 00:00:00 2001
From: Ivan Enderlin <ivan.enderlin@hoa-project.net>
Date: Wed, 4 Dec 2019 14:52:58 +0100
Subject: [PATCH 13/15] doc(changelog) Resolve merge issues.

---
 CHANGELOG.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index b339615c989..fc2ad7754ea 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,7 +5,7 @@
 - [#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.
 - [#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) Fix `get_wasi_version` when a module has multiple import namespaces.
+- [#1028](https://github.com/wasmerio/wasmer/pull/1028) Introduce strict/non-strict modes for `get_wasi_version`
 - [#1006](https://github.com/wasmerio/wasmer/pull/1006) Fix minor panic issue when `wasmer::compile_with` called with llvm backend
 - [#1009](https://github.com/wasmerio/wasmer/pull/1009) Enable LLVM verifier for all tests, add new llvm-backend-tests crate.
 - [#1022](https://github.com/wasmerio/wasmer/pull/1022) Add caching support for Singlepass backend.

From 4ef799f23d6f86e2533cd254374cb39320faddeb Mon Sep 17 00:00:00 2001
From: Ivan Enderlin <ivan.enderlin@hoa-project.net>
Date: Wed, 4 Dec 2019 15:34:56 +0100
Subject: [PATCH 14/15] feat(runtime-c-api) Support `WasiVersion::Latest`.

---
 CHANGELOG.md                         |  2 +-
 lib/runtime-c-api/src/import/wasi.rs | 24 +++++++++++++++++-------
 lib/runtime-c-api/wasmer.h           |  9 +++++++--
 lib/runtime-c-api/wasmer.hh          |  7 +++++--
 4 files changed, 30 insertions(+), 12 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index fc2ad7754ea..495361d2876 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,9 +2,9 @@
 
 ## **[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.
-- [#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`
 - [#1006](https://github.com/wasmerio/wasmer/pull/1006) Fix minor panic issue when `wasmer::compile_with` called with llvm backend
 - [#1009](https://github.com/wasmerio/wasmer/pull/1009) Enable LLVM verifier for all tests, add new llvm-backend-tests crate.
diff --git a/lib/runtime-c-api/src/import/wasi.rs b/lib/runtime-c-api/src/import/wasi.rs
index 6d7e6a52352..0ff833a61f5 100644
--- a/lib/runtime-c-api/src/import/wasi.rs
+++ b/lib/runtime-c-api/src/import/wasi.rs
@@ -8,17 +8,24 @@ use wasmer_wasi as wasi;
 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 = 1,
+    Snapshot0 = 2,
+
     /// `wasi_snapshot_preview1`.
-    Snapshot1 = 2,
+    Snapshot1 = 3,
 }
 
 impl From<c_uchar> for Version {
     fn from(value: c_uchar) -> Self {
         match value {
-            1 => Self::Snapshot0,
-            2 => Self::Snapshot1,
+            1 => Self::Latest,
+            2 => Self::Snapshot0,
+            3 => Self::Snapshot1,
             _ => Self::Unknown,
         }
     }
@@ -66,7 +73,7 @@ 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::Snapshot1,
+        Version::Latest,
         arg_list,
         env_list,
         preopened_file_list,
@@ -123,6 +130,7 @@ pub unsafe extern "C" fn wasmer_wasi_get_version(module: *const wasmer_module_t)
         Some(version) => match version {
             wasi::WasiVersion::Snapshot0 => Version::Snapshot0,
             wasi::WasiVersion::Snapshot1 => Version::Snapshot1,
+            wasi::WasiVersion::Latest => Version::Latest,
         },
         None => Version::Unknown,
     }
@@ -151,6 +159,7 @@ fn wasmer_wasi_generate_import_object_inner(
         .collect::<Result<Vec<_>, _>>()?;
 
     let version = match version {
+        Version::Latest => wasi::WasiVersion::Latest,
         Version::Snapshot0 => wasi::WasiVersion::Snapshot0,
         Version::Snapshot1 => wasi::WasiVersion::Snapshot1,
         _ => panic!("Version {:?} is invalid.", version),
@@ -186,7 +195,8 @@ mod tests {
     #[test]
     fn test_versions_from_uint() {
         assert_eq!(Version::Unknown, 0.into());
-        assert_eq!(Version::Snapshot0, 1.into());
-        assert_eq!(Version::Snapshot1, 2.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/wasmer.h b/lib/runtime-c-api/wasmer.h
index 1440b16dcd9..de921e3b04d 100644
--- a/lib/runtime-c-api/wasmer.h
+++ b/lib/runtime-c-api/wasmer.h
@@ -30,14 +30,19 @@ 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 = 1,
+  Snapshot0 = 2,
   /**
    * `wasi_snapshot_preview1`.
    */
-  Snapshot1 = 2,
+  Snapshot1 = 3,
 };
 typedef uint8_t Version;
 
diff --git a/lib/runtime-c-api/wasmer.hh b/lib/runtime-c-api/wasmer.hh
index 5366ee88d41..09b58f86100 100644
--- a/lib/runtime-c-api/wasmer.hh
+++ b/lib/runtime-c-api/wasmer.hh
@@ -28,10 +28,13 @@
 enum class Version : uint8_t {
   /// Version cannot be detected or is unknown.
   Unknown = 0,
+  /// Latest version. See `wasmer_wasi::WasiVersion::Latest` to
+  /// leran more.
+  Latest = 1,
   /// `wasi_unstable`.
-  Snapshot0 = 1,
+  Snapshot0 = 2,
   /// `wasi_snapshot_preview1`.
-  Snapshot1 = 2,
+  Snapshot1 = 3,
 };
 
 /// List of export/import kinds.

From 45e4081e4b71573d453614b20ecda1b200d82306 Mon Sep 17 00:00:00 2001
From: Ivan Enderlin <ivan.enderlin@hoa-project.net>
Date: Fri, 6 Dec 2019 15:02:48 +0100
Subject: [PATCH 15/15] doc(changelog) Remove a duplication.

---
 CHANGELOG.md | 1 -
 1 file changed, 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 495361d2876..60ff42f8b9b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,7 +5,6 @@
 - [#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.
-- [#1028](https://github.com/wasmerio/wasmer/pull/1028) Introduce strict/non-strict modes for `get_wasi_version`
 - [#1006](https://github.com/wasmerio/wasmer/pull/1006) Fix minor panic issue when `wasmer::compile_with` called with llvm backend
 - [#1009](https://github.com/wasmerio/wasmer/pull/1009) Enable LLVM verifier for all tests, add new llvm-backend-tests crate.
 - [#1022](https://github.com/wasmerio/wasmer/pull/1022) Add caching support for Singlepass backend.