Implement delegate_call (#80)

crates/runtime-api/src/calling_convention.rs

@@ -106,3 +106,30 @@ pub fn call(context: &Context) -> StructType {
         true,
     )
 }
+
+/// Returns a packed struct argument type for the `delegate_call` API.
+pub fn delegate_call(context: &Context) -> StructType {
+    context.struct_type(
+        &[
+            // flags: u32,
+            context.i32_type().as_basic_type_enum(),
+            // address_ptr:
+            context.ptr_type(Default::default()).as_basic_type_enum(),
+            // ref_time_limit: u64,
+            context.i64_type().as_basic_type_enum(),
+            // proof_size_limit: u64,
+            context.i64_type().as_basic_type_enum(),
+            // deposit_ptr: u32,
+            context.ptr_type(Default::default()).as_basic_type_enum(),
+            // input_data_ptr: u32,
+            context.ptr_type(Default::default()).as_basic_type_enum(),
+            // input_data_len: u32,
+            context.i32_type().as_basic_type_enum(),
+            // output_ptr: u32,
+            context.ptr_type(Default::default()).as_basic_type_enum(),
+            // output_len_ptr: u32,
+            context.ptr_type(Default::default()).as_basic_type_enum(),
+        ],
+        true,
+    )
+}

crates/runtime-api/src/polkavm_imports.c

@@ -76,6 +76,8 @@ POLKAVM_IMPORT(void, block_number, uint32_t)
 
 POLKAVM_IMPORT(uint32_t, call, uint32_t)
 
+POLKAVM_IMPORT(uint32_t, delegate_call, uint32_t)
+
 POLKAVM_IMPORT(void, caller, uint32_t)
 
 POLKAVM_IMPORT(void, chain_id, uint32_t)

crates/runtime-api/src/polkavm_imports.rs

@@ -26,6 +26,8 @@ pub static BLOCK_NUMBER: &str = "block_number";
 
 pub static CALL: &str = "call";
 
+pub static DELEGATE_CALL: &str = "delegate_call";
+
 pub static CALLER: &str = "caller";
 
 pub static CHAIN_ID: &str = "chain_id";
@@ -64,7 +66,7 @@ pub static VALUE_TRANSFERRED: &str = "value_transferred";
 
 /// All imported runtime API symbols.
 /// Useful for configuring common attributes and linkage.
-pub static IMPORTS: [&str; 26] = [
+pub static IMPORTS: [&str; 27] = [
     SBRK,
     MEMORY_SIZE,
     ADDRESS,
@@ -73,6 +75,7 @@ pub static IMPORTS: [&str; 26] = [
     BLOCK_HASH,
     BLOCK_NUMBER,
     CALL,
+    DELEGATE_CALL,
     CALLER,
     CHAIN_ID,
     CODE_SIZE,