Merge pull request #50 from multiversx/fix-capi-safe-unwind

safe c-api unwind wrapper

Cargo.toml

@@ -2,6 +2,7 @@
 resolver = "2"
 
 members = [
+    "meta",
     "c-api",
     "vm-executor",
     "vm-executor-wasmer",

c-api/Cargo.toml

@@ -8,6 +8,7 @@ publish = false
 crate-type = ["cdylib"]
 
 [dependencies]
+meta = { path = "../meta" }
 multiversx-chain-vm-executor = { path = "../vm-executor" }
 multiversx-chain-vm-executor-wasmer = { path = "../vm-executor-wasmer" }
 

c-api/src/basic_types.rs

@@ -13,6 +13,7 @@ pub enum vm_exec_result_t {
     VM_EXEC_ERROR = 2,
 }
 
+#[allow(non_camel_case_types)]
 #[repr(C)]
 pub struct vm_exec_byte_array {
     pub bytes: *const u8,
@@ -74,6 +75,7 @@ pub(crate) unsafe fn string_copy(
     s.len() as c_int + 1
 }
 
+#[allow(non_camel_case_types)]
 #[repr(C)]
 pub struct vm_exec_byte_array_list {
     pub arrays: *const vm_exec_byte_array,

c-api/src/capi_breakpoints.rs

@@ -1,3 +1,4 @@
+use meta::capi_safe_unwind;
 use multiversx_chain_vm_executor::Instance;
 
 use crate::capi_instance::{vm_exec_instance_t, CapiInstance};
@@ -15,6 +16,7 @@ use crate::vm_exec_result_t;
 /// C API function, works with raw object pointers.
 #[allow(clippy::cast_ptr_alignment)]
 #[no_mangle]
+#[capi_safe_unwind(vm_exec_result_t::VM_EXEC_ERROR)]
 pub unsafe extern "C" fn vm_exec_instance_set_breakpoint_value(
     instance_ptr: *const vm_exec_instance_t,
     value: u64,
@@ -37,6 +39,7 @@ pub unsafe extern "C" fn vm_exec_instance_set_breakpoint_value(
 /// C API function, works with raw object pointers.
 #[allow(clippy::cast_ptr_alignment)]
 #[no_mangle]
+#[capi_safe_unwind(0)]
 pub unsafe extern "C" fn vm_exec_instance_get_breakpoint_value(
     instance_ptr: *const vm_exec_instance_t,
 ) -> u64 {

c-api/src/capi_executor.rs

@@ -5,9 +5,11 @@ use crate::{
     service_singleton::with_service, vm_exec_result_t,
 };
 use libc::c_void;
+use meta::capi_safe_unwind;
 use multiversx_chain_vm_executor::Executor;
 use multiversx_chain_vm_executor_wasmer::force_sighandler_reinstall;
 
+#[allow(non_camel_case_types)]
 #[repr(C)]
 pub struct vm_exec_executor_t;
 
@@ -22,6 +24,7 @@ pub struct CapiExecutor {
 /// C API function, works with raw object pointers.
 #[allow(clippy::cast_ptr_alignment)]
 #[no_mangle]
+#[capi_safe_unwind(vm_exec_result_t::VM_EXEC_ERROR)]
 pub unsafe extern "C" fn vm_exec_new_executor(
     executor: *mut *mut vm_exec_executor_t,
     vm_hook_pointers_ptr_ptr: *mut *mut vm_exec_vm_hook_c_func_pointers,
@@ -74,19 +77,27 @@ pub unsafe extern "C" fn vm_force_sighandler_reinstall() {
 /// C API function, works with raw object pointers.
 #[allow(clippy::cast_ptr_alignment)]
 #[no_mangle]
+#[capi_safe_unwind(vm_exec_result_t::VM_EXEC_ERROR)]
 pub unsafe extern "C" fn vm_exec_executor_set_vm_hooks_ptr(
     executor_ptr: *mut vm_exec_executor_t,
     vm_hooks_ptr: *mut c_void,
 ) -> vm_exec_result_t {
-    let capi_executor = cast_input_ptr!(executor_ptr, CapiExecutor, "executor ptr is null");
+    let result = std::panic::catch_unwind(|| {
+        let capi_executor = cast_input_ptr!(executor_ptr, CapiExecutor, "executor ptr is null");
 
-    let result = capi_executor.content.set_vm_hooks_ptr(vm_hooks_ptr);
-    match result {
-        Ok(()) => vm_exec_result_t::VM_EXEC_OK,
-        Err(message) => {
-            with_service(|service| service.update_last_error_str(message.to_string()));
-            vm_exec_result_t::VM_EXEC_ERROR
+        let result = capi_executor.content.set_vm_hooks_ptr(vm_hooks_ptr);
+        match result {
+            Ok(()) => vm_exec_result_t::VM_EXEC_OK,
+            Err(message) => {
+                with_service(|service| service.update_last_error_str(message.to_string()));
+                vm_exec_result_t::VM_EXEC_ERROR
+            }
         }
+    });
+
+    match result {
+        Ok(result) => result,
+        Err(_) => vm_exec_result_t::VM_EXEC_ERROR,
     }
 }
 

c-api/src/capi_instance.rs

@@ -5,6 +5,7 @@ use crate::{
     service_singleton::with_service,
     string_copy, vm_exec_result_t,
 };
+use meta::capi_safe_unwind;
 use libc::{c_char, c_int};
 use multiversx_chain_vm_executor::{CompilationOptions, Instance};
 use std::{ffi::CStr, slice};
@@ -14,9 +15,11 @@ use std::{ffi::CStr, slice};
 /// A `wasmer_runtime::Instance` represents a WebAssembly instance. It
 /// is generally generated by the `wasmer_instantiate()` function, or by
 /// the `wasmer_module_instantiate()` function for the most common paths.
+#[allow(non_camel_case_types)]
 #[repr(C)]
 pub struct vm_exec_instance_t;
 
+#[allow(non_camel_case_types)]
 #[repr(C)]
 pub struct vm_exec_compilation_options_t;
 
@@ -33,6 +36,7 @@ pub struct CapiInstance {
 /// C API function, works with raw object pointers.
 #[allow(clippy::cast_ptr_alignment)]
 #[no_mangle]
+#[capi_safe_unwind(vm_exec_result_t::VM_EXEC_ERROR)]
 pub unsafe extern "C" fn vm_exec_new_instance(
     executor_ptr: *mut vm_exec_executor_t,
     instance_ptr_ptr: *mut *mut vm_exec_instance_t,
@@ -86,6 +90,7 @@ pub unsafe extern "C" fn vm_exec_new_instance(
 /// C API function, works with raw object pointers.
 #[allow(clippy::cast_ptr_alignment)]
 #[no_mangle]
+#[capi_safe_unwind(vm_exec_result_t::VM_EXEC_ERROR)]
 pub unsafe extern "C" fn vm_exec_instance_call(
     instance_ptr: *mut vm_exec_instance_t,
     func_name_ptr: *const c_char,
@@ -119,6 +124,7 @@ pub unsafe extern "C" fn vm_exec_instance_call(
 /// C API function, works with raw object pointers.
 #[allow(clippy::cast_ptr_alignment)]
 #[no_mangle]
+#[capi_safe_unwind(vm_exec_result_t::VM_EXEC_ERROR)]
 pub unsafe extern "C" fn vm_check_signatures(
     instance_ptr: *mut vm_exec_instance_t,
 ) -> vm_exec_result_t {
@@ -142,6 +148,7 @@ pub unsafe extern "C" fn vm_check_signatures(
 /// C API function, works with raw object pointers.
 #[allow(clippy::cast_ptr_alignment)]
 #[no_mangle]
+#[capi_safe_unwind(-1)]
 pub unsafe extern "C" fn vm_exec_instance_has_function(
     instance_ptr: *mut vm_exec_instance_t,
     func_name_ptr: *const c_char,
@@ -163,6 +170,7 @@ pub unsafe extern "C" fn vm_exec_instance_has_function(
 /// C API function, works with raw object pointers.
 #[allow(clippy::cast_ptr_alignment)]
 #[no_mangle]
+#[capi_safe_unwind(0)]
 pub unsafe extern "C" fn vm_exported_function_names_length(
     instance_ptr: *mut vm_exec_instance_t,
 ) -> c_int {
@@ -190,6 +198,7 @@ pub unsafe extern "C" fn vm_exported_function_names_length(
 /// C API function, works with raw object pointers.
 #[allow(clippy::cast_ptr_alignment)]
 #[no_mangle]
+#[capi_safe_unwind(0)]
 pub unsafe extern "C" fn vm_exported_function_names(
     instance_ptr: *mut vm_exec_instance_t,
     dest_buffer: *mut c_char,
@@ -228,6 +237,7 @@ pub unsafe extern "C" fn vm_exec_instance_destroy(instance_ptr: *mut vm_exec_ins
 /// C API function, works with raw object pointers.
 #[allow(clippy::cast_ptr_alignment)]
 #[no_mangle]
+#[capi_safe_unwind(vm_exec_result_t::VM_EXEC_ERROR)]
 pub unsafe extern "C" fn vm_exec_instance_reset(
     instance_ptr: *mut vm_exec_instance_t,
 ) -> vm_exec_result_t {

c-api/src/capi_instance_cache.rs

@@ -1,5 +1,6 @@
 use std::slice;
 
+use meta::capi_safe_unwind;
 use multiversx_chain_vm_executor::CompilationOptions;
 
 use crate::{
@@ -16,6 +17,7 @@ use crate::{
 /// C API function, works with raw object pointers.
 #[allow(clippy::cast_ptr_alignment)]
 #[no_mangle]
+#[capi_safe_unwind(vm_exec_result_t::VM_EXEC_ERROR)]
 pub unsafe extern "C" fn vm_exec_instance_cache(
     instance_ptr: *const vm_exec_instance_t,
     cache_bytes_ptr: *mut *const u8,
@@ -47,6 +49,7 @@ pub unsafe extern "C" fn vm_exec_instance_cache(
 /// C API function, works with raw object pointers.
 #[allow(clippy::cast_ptr_alignment, unused_variables)]
 #[no_mangle]
+#[capi_safe_unwind(vm_exec_result_t::VM_EXEC_ERROR)]
 pub unsafe extern "C" fn vm_exec_instance_from_cache(
     executor_ptr: *mut vm_exec_executor_t,
     instance_ptr_ptr: *mut *mut vm_exec_instance_t,

c-api/src/capi_logger.rs

@@ -1,9 +1,11 @@
+use meta::capi_safe_unwind;
 use multiversx_chain_vm_executor_wasmer::{set_log_level, u64_to_log_level};
 
 use crate::{basic_types::vm_exec_result_t, service_singleton::with_service};
 
 /// Sets the log level.
 #[no_mangle]
+#[capi_safe_unwind(vm_exec_result_t::VM_EXEC_ERROR)]
 pub extern "C" fn vm_exec_set_log_level(value: u64) -> vm_exec_result_t {
     let result = u64_to_log_level(value);
 

c-api/src/capi_memory.rs

@@ -1,5 +1,7 @@
 //! Instantiate a module, call functions, and read exports.
 
+use meta::capi_safe_unwind;
+
 use crate::{
     capi_instance::{vm_exec_instance_t, CapiInstance},
     service_singleton::with_service,
@@ -16,6 +18,7 @@ use std::ptr;
 /// C API function, works with raw object pointers.
 #[allow(clippy::cast_ptr_alignment)]
 #[no_mangle]
+#[capi_safe_unwind(0)]
 pub unsafe extern "C" fn vm_exec_instance_memory_data_length(
     instance_ptr: *mut vm_exec_instance_t,
 ) -> u64 {
@@ -43,6 +46,7 @@ pub unsafe extern "C" fn vm_exec_instance_memory_data_length(
 /// C API function, works with raw object pointers.
 #[allow(clippy::cast_ptr_alignment)]
 #[no_mangle]
+#[capi_safe_unwind(ptr::null_mut())]
 pub unsafe extern "C" fn vm_exec_instance_memory_data(
     instance_ptr: *mut vm_exec_instance_t,
 ) -> *mut u8 {
@@ -74,6 +78,7 @@ pub unsafe extern "C" fn vm_exec_instance_memory_data(
 /// C API function, works with raw object pointers.
 #[allow(clippy::cast_ptr_alignment)]
 #[no_mangle]
+#[capi_safe_unwind(vm_exec_result_t::VM_EXEC_ERROR)]
 pub unsafe extern "C" fn vm_exec_instance_memory_grow(
     instance_ptr: *mut vm_exec_instance_t,
     by_num_pages: u32,

c-api/src/capi_metering.rs

@@ -2,6 +2,7 @@ use crate::capi_executor::{vm_exec_executor_t, CapiExecutor};
 use crate::capi_instance::{vm_exec_instance_t, CapiInstance};
 use crate::service_singleton::with_service;
 use crate::vm_exec_result_t;
+use meta::capi_safe_unwind;
 use multiversx_chain_vm_executor::OpcodeCost;
 
 #[allow(non_camel_case_types)]
@@ -19,6 +20,7 @@ pub struct vm_exec_opcode_cost_t;
 /// C API function, works with raw object pointers.
 #[allow(clippy::cast_ptr_alignment)]
 #[no_mangle]
+#[capi_safe_unwind(vm_exec_result_t::VM_EXEC_ERROR)]
 pub unsafe extern "C" fn vm_exec_set_opcode_costs(
     executor_ptr: *mut vm_exec_executor_t,
     opcode_cost_ptr: *const vm_exec_opcode_cost_t,
@@ -47,6 +49,7 @@ pub unsafe extern "C" fn vm_exec_set_opcode_costs(
 /// C API function, works with raw object pointers.
 #[allow(clippy::cast_ptr_alignment)]
 #[no_mangle]
+#[capi_safe_unwind(vm_exec_result_t::VM_EXEC_ERROR)]
 pub unsafe extern "C" fn vm_exec_instance_set_points_limit(
     instance_ptr: *const vm_exec_instance_t,
     limit: u64,
@@ -73,6 +76,7 @@ pub unsafe extern "C" fn vm_exec_instance_set_points_limit(
 /// C API function, works with raw object pointers.
 #[allow(clippy::cast_ptr_alignment)]
 #[no_mangle]
+#[capi_safe_unwind(vm_exec_result_t::VM_EXEC_ERROR)]
 pub unsafe extern "C" fn vm_exec_instance_set_points_used(
     instance_ptr: *const vm_exec_instance_t,
     points: u64,
@@ -95,6 +99,7 @@ pub unsafe extern "C" fn vm_exec_instance_set_points_used(
 /// C API function, works with raw object pointers.
 #[allow(clippy::cast_ptr_alignment)]
 #[no_mangle]
+#[capi_safe_unwind(0)]
 pub unsafe extern "C" fn vm_exec_instance_get_points_used(
     instance_ptr: *const vm_exec_instance_t,
 ) -> u64 {

c-api/src/macros.rs

@@ -46,4 +46,4 @@ macro_rules! cast_input_const_ptr {
             vm_exec_result_t::VM_EXEC_ERROR
         )
     };
-}
+}

meta/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "meta"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+proc-macro = true
+
+[dependencies]
+syn = "2.0.77"
+quote = "1.0.9"

meta/src/lib.rs

@@ -0,0 +1,24 @@
+use proc_macro::TokenStream;
+use quote::quote;
+
+#[proc_macro_attribute]
+pub fn capi_safe_unwind(attr: TokenStream, item: TokenStream) -> TokenStream {
+    let func = syn::parse_macro_input!(item as syn::ItemFn);
+    let fail_return = syn::parse_macro_input!(attr as syn::Expr);
+
+    let signature = &func.sig;
+    let body = &func.block;
+    let attributes = &func.attrs;
+    let vis = &func.vis;
+
+    quote! {
+        #(#attributes)*
+        #vis #signature {
+            let result = std::panic::catch_unwind(|| #body);
+            match result {
+                Ok(result) => result,
+                Err(_) => #fail_return,
+            }
+        }
+    }.into()
+}