Merge #1761

1761: feat(c-api) Implement the `traps` argument of `wasm_instance_new` r=Hywan a=Hywan # Description When running `Instance::new`, it can error with an `InstantiationError`. There is 2 scenarii: 1. Either it's a `InstantiationError::Link`. In this case, the `wasm_instance_new` function must return `NULL` and register the error in the Wasmer error registry. 2. Either it's a `InstantiationError::Start`. In this case, the `wasm_instance_new` function must return `NULL` and the error must be converted into a `wasm_trap_t`, which is stored in the `wasm_trap_t**` array. This array is initialized by `wasm_instance_new` itself. # Review - [x] Add a short description of the the change to the CHANGELOG.md file Fixes #1744. Co-authored-by: Ivan Enderlin <[email protected]>
wasmerio · Oct 30, 2020 · 2d59b27 · 2d59b27
2 parents ff3a6c8 + bdb0dc7
commit 2d59b27
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Showing 3 changed files with 28 additions and 11 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -8,8 +8,10 @@
 ## **[Unreleased]**
 
 - [#1710](https://github.com/wasmerio/wasmer/pull/1710) Memory for function call trampolines is now owned by the Artifact.
+
 ### Added
 
+- [#1761](https://github.com/wasmerio/wasmer/pull/1761) Implement the `wasm_trap_t**` argument of `wasm_instance_new` in the Wasm C API.
 - [#1687](https://github.com/wasmerio/wasmer/pull/1687) Add basic table example; fix ownership of local memory and local table metadata in the VM.
 - [#1751](https://github.com/wasmerio/wasmer/pull/1751) Implement `wasm_trap_t` inside a function declared with `wasm_func_new_with_env` in the Wasm C API.
 - [#1741](https://github.com/wasmerio/wasmer/pull/1741) Implement `wasm_memory_type` in the Wasm C API.

diff --git a/lib/c-api/src/wasm_c_api/instance.rs b/lib/c-api/src/wasm_c_api/instance.rs
@@ -5,7 +5,7 @@ use super::trap::wasm_trap_t;
 use crate::ordered_resolver::OrderedResolver;
 use std::mem;
 use std::sync::Arc;
-use wasmer::{Extern, Instance};
+use wasmer::{Extern, Instance, InstantiationError};
 
 #[allow(non_camel_case_types)]
 pub struct wasm_instance_t {
@@ -17,8 +17,7 @@ pub unsafe extern "C" fn wasm_instance_new(
     _store: &wasm_store_t,
     module: &wasm_module_t,
     imports: &wasm_extern_vec_t,
-    // own
-    _traps: *mut *mut wasm_trap_t,
+    traps: *mut *mut wasm_trap_t,
 ) -> Option<Box<wasm_instance_t>> {
     let wasm_module = &module.inner;
     let module_imports = wasm_module.imports();
@@ -32,7 +31,23 @@ pub unsafe extern "C" fn wasm_instance_new(
         .cloned()
         .collect();
 
-    let instance = Arc::new(c_try!(Instance::new(wasm_module, &resolver)));
+    let instance = match Instance::new(wasm_module, &resolver) {
+        Ok(instance) => Arc::new(instance),
+
+        Err(InstantiationError::Link(link_error)) => {
+            crate::error::update_last_error(link_error);
+
+            return None;
+        }
+
+        Err(InstantiationError::Start(runtime_error)) => {
+            let trap: Box<wasm_trap_t> = Box::new(runtime_error.into());
+            *traps = Box::into_raw(trap);
+
+            return None;
+        }
+    };
+
     Some(Box::new(wasm_instance_t { inner: instance }))
 }
 

diff --git a/lib/c-api/tests/wasm_c_api/CMakeLists.txt b/lib/c-api/tests/wasm_c_api/CMakeLists.txt
@@ -11,7 +11,7 @@ add_executable(wasm-c-api-hello wasm-c-api/example/hello.c)
 #add_executable(wasm-c-api-multi wasm-c-api/example/multi.c)
 add_executable(wasm-c-api-reflect wasm-c-api/example/reflect.c)
 add_executable(wasm-c-api-serialize wasm-c-api/example/serialize.c)
-#add_executable(wasm-c-api-start wasm-c-api/example/start.c)
+add_executable(wasm-c-api-start wasm-c-api/example/start.c)
 #add_executable(wasm-c-api-table wasm-c-api/example/table.c)
 #add_executable(wasm-c-api-threads wasm-c-api/example/threads.c)
 add_executable(wasm-c-api-trap wasm-c-api/example/trap.c)
@@ -106,12 +106,12 @@ add_test(NAME wasm-c-api-serialize
          WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/wasm-c-api/example/
 )
 
-#target_link_libraries(wasm-c-api-start general ${WASMER_LIB})
-#target_compile_options(wasm-c-api-start PRIVATE ${COMPILER_OPTIONS})
-#add_test(NAME wasm-c-api-start
-#         COMMAND wasm-c-api-start
-#         WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/wasm-c-api/example/
-#)
+target_link_libraries(wasm-c-api-start general ${WASMER_LIB})
+target_compile_options(wasm-c-api-start PRIVATE ${COMPILER_OPTIONS})
+add_test(NAME wasm-c-api-start
+         COMMAND wasm-c-api-start
+         WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/wasm-c-api/example/
+)
 
 #target_link_libraries(wasm-c-api-table general ${WASMER_LIB})
 #target_compile_options(wasm-c-api-table PRIVATE ${COMPILER_OPTIONS})