Merge #1728

1728: Fix bugs in object file engine r=syrusakbary a=MarkMcCaskey

Still fixing some bugs, work in progress

# Review

- [ ] Add a short description of the the change to the CHANGELOG.md file


Co-authored-by: Mark McCaskey <mark@wasmer.io>
Co-authored-by: Syrus <me@syrusakbary.com>

lib/c-api/build.rs

@@ -382,7 +382,6 @@ fn exclude_items_from_wasm_c_api(builder: Builder) -> Builder {
         .exclude_item("wasi_version_t")
         .exclude_item("wasm_config_set_compiler")
         .exclude_item("wasm_config_set_engine")
-        .exclude_item("wasm_instance_get_vmctx_ptr")
         .exclude_item("wasm_module_name")
         .exclude_item("wasm_module_set_name")
         .exclude_item("wasmer_compiler_t")

lib/c-api/src/wasm_c_api/wasmer.rs

@@ -1,17 +1,10 @@
 //! Wasmer-specific extensions to the Wasm C API.
 
-use super::instance::wasm_instance_t;
 use super::module::wasm_module_t;
 use super::types::wasm_name_t;
-use std::ffi::c_void;
 use std::str;
 use std::sync::Arc;
 
-#[no_mangle]
-pub unsafe extern "C" fn wasm_instance_get_vmctx_ptr(instance: &wasm_instance_t) -> *mut c_void {
-    instance.inner.vmctx_ptr() as _
-}
-
 #[no_mangle]
 pub unsafe extern "C" fn wasm_module_name(module: &wasm_module_t, out: &mut wasm_name_t) {
     let name = match module.inner.name() {

lib/c-api/wasmer_wasm.h

@@ -162,8 +162,6 @@ void wasm_config_set_compiler(wasm_config_t *config, wasmer_compiler_t compiler)
 
 void wasm_config_set_engine(wasm_config_t *config, wasmer_engine_t engine);
 
-void *wasm_instance_get_vmctx_ptr(const wasm_instance_t *instance);
-
 void wasm_module_name(const wasm_module_t *module, wasm_name_t *out);
 
 bool wasm_module_set_name(wasm_module_t *module, const wasm_name_t *name);

lib/cli/src/commands/wasmer_create_exe_main.c

@@ -9,6 +9,8 @@ extern "C" {
 #include <stdio.h>
 #include <stdlib.h>
 
+#define own
+
 // TODO: make this define templated so that the Rust code can toggle it on/off
 #define WASI
 
@@ -158,11 +160,21 @@ int main(int argc, char* argv[]) {
   wasi_env_set_instance(wasi_env, instance);
   #endif
 
-  void* vmctx = wasm_instance_get_vmctx_ptr(instance);
-  wasm_val_t* inout[2] = { NULL, NULL };
-
-  // We're able to call our compiled function directly through a trampoline.
-  wasmer_trampoline_function_call__1(vmctx, wasmer_function__1, &inout);
+  #ifdef WASI
+  own wasm_func_t* start_function = wasi_get_start_function(instance);
+  if (!start_function) {
+    fprintf(stderr, "`_start` function not found\n");
+    print_wasmer_error();
+    return -1;
+  }
+  own wasm_trap_t* trap = wasm_func_call(start_function, NULL, NULL);
+  if (trap) {
+    fprintf(stderr, "Trap is not NULL: TODO:\n");
+    return -1;
+  }
+  #endif
+
+  // TODO: handle non-WASI start (maybe with invoke?)
 
   wasm_instance_delete(instance);
   wasm_module_delete(module);

lib/engine-object-file/README.md

@@ -36,6 +36,8 @@ extern "C" {
 #include <stdio.h>
 #include <stdlib.h>
 
+#define own
+
 #ifdef __cplusplus
 }
 #endif
@@ -100,13 +102,19 @@ int main() {
         wasi_env_set_instance(wasi_env, instance);
 
         // WASI is now set up.
-
-        void* vmctx = wasm_instance_get_vmctx_ptr(instance);
-        wasm_val_t* inout[2] = { NULL, NULL };
+        own wasm_func_t* start_function = wasi_get_start_function(instance);
+        if (!start_function) {
+                fprintf(stderr, "`_start` function not found\n");
+                print_wasmer_error();
+                return -1;
+        }
 
         fflush(stdout);
-        // We're able to call our compiled function directly through a trampoline.
-        wasmer_trampoline_function_call__1(vmctx, wasmer_function__1, &inout);
+        own wasm_trap_t* trap = wasm_func_call(start_function, NULL, NULL);
+        if (trap) {
+                fprintf(stderr, "Trap is not NULL: TODO:\n");
+                return -1;
+        }
 
         wasm_instance_delete(instance);
         wasm_module_delete(module);

lib/vm/src/libcalls.rs

@@ -464,6 +464,11 @@ impl LibCall {
             Self::FloorF64 => "wasmer_f64_floor",
             Self::NearestF32 => "wasmer_f32_nearest",
             Self::NearestF64 => "wasmer_f64_nearest",
+            // We have to do this because macOS requires a leading `_` and it's not
+            // a normal function, it's a static variable, so we have to do it manually.
+            #[cfg(target_os = "macos")]
+            Self::Probestack => "_wasmer_probestack",
+            #[cfg(not(target_os = "macos"))]
             Self::Probestack => "wasmer_probestack",
             Self::RaiseTrap => "wasmer_raise_trap",
             Self::TruncF32 => "wasmer_f32_trunc",

tests/integration/cli/tests/object_file_engine_test_c_source.c

@@ -9,6 +9,8 @@ extern "C" {
 #include <stdio.h>
 #include <stdlib.h>
 
+#define own
+
 #ifdef __cplusplus
 }
 #endif
@@ -73,13 +75,19 @@ int main() {
         wasi_env_set_instance(wasi_env, instance);
 
         // WASI is now set up.
-
-        void* vmctx = wasm_instance_get_vmctx_ptr(instance);
-        wasm_val_t* inout[2] = { NULL, NULL };
+        own wasm_func_t* start_function = wasi_get_start_function(instance);
+        if (!start_function) {
+                fprintf(stderr, "`_start` function not found\n");
+                print_wasmer_error();
+                return -1;
+        }
 
         fflush(stdout);
-        // We're able to call our compiled function directly through a trampoline.
-        wasmer_trampoline_function_call__1(vmctx, wasmer_function__1, &inout);
+        own wasm_trap_t* trap = wasm_func_call(start_function, NULL, NULL);
+        if (trap) {
+                fprintf(stderr, "Trap is not NULL: TODO:\n");
+                return -1;
+        }
 
         wasm_instance_delete(instance);
         wasm_module_delete(module);