Remove scratch buffer from ext_instantiate

frame/contracts/fixtures/caller_contract.wat

@@ -3,7 +3,7 @@
 	(import "env" "ext_scratch_read" (func $ext_scratch_read (param i32 i32 i32)))
 	(import "env" "ext_balance" (func $ext_balance (param i32 i32)))
 	(import "env" "ext_call" (func $ext_call (param i32 i32 i64 i32 i32 i32 i32 i32 i32) (result i32)))
-	(import "env" "ext_instantiate" (func $ext_instantiate (param i32 i32 i64 i32 i32 i32 i32) (result i32)))
+	(import "env" "ext_instantiate" (func $ext_instantiate (param i32 i32 i64 i32 i32 i32 i32 i32 i32 i32 i32) (result i32)))
 	(import "env" "ext_println" (func $ext_println (param i32 i32)))
 	(import "env" "memory" (memory 1 1))
 
@@ -69,6 +69,10 @@
 				(i32.const 8)	;; Length of the buffer with value to transfer.
 				(i32.const 9)	;; Pointer to input data buffer address
 				(i32.const 7)	;; Length of input data buffer
+				(i32.const 4294967295) ;; u32 max sentinel value: do not copy address
+				(i32.const 0) ;; Length is ignored in this case
+				(i32.const 4294967295) ;; u32 max sentinel value: do not copy output
+				(i32.const 0) ;; Length is ignored in this case
 			)
 		)
 
@@ -77,11 +81,6 @@
 			(i32.eq (get_local $exit_code) (i32.const 0x11))
 		)
 
-		;; Check that scratch buffer is empty since contract instantiation failed.
-		(call $assert
-			(i32.eq (call $ext_scratch_size) (i32.const 0))
-		)
-
 		;; Check that balance has not changed.
 		(call $assert
 			(i64.eq (get_local $balance) (call $current_balance (get_local $sp)))
@@ -97,6 +96,10 @@
 				(i32.const 8)	;; Length of the buffer with value to transfer.
 				(i32.const 8)	;; Pointer to input data buffer address
 				(i32.const 8)	;; Length of input data buffer
+				(i32.const 4294967295) ;; u32 max sentinel value: do not copy address
+				(i32.const 0) ;; Length is ignored in this case
+				(i32.const 4294967295) ;; u32 max sentinel value: do not copy output
+				(i32.const 0) ;; Length is ignored in this case
 			)
 		)
 
@@ -105,16 +108,17 @@
 			(i32.eq (get_local $exit_code) (i32.const 0x0100))
 		)
 
-		;; Check that scratch buffer is empty since contract instantiation failed.
-		(call $assert
-			(i32.eq (call $ext_scratch_size) (i32.const 0))
-		)
-
 		;; Check that balance has not changed.
 		(call $assert
 			(i64.eq (get_local $balance) (call $current_balance (get_local $sp)))
 		)
 
+		;; Length of the output buffer
+		(i32.store
+			(i32.sub (get_local $sp) (i32.const 4))
+			(i32.const 8)
+		)
+
 		;; Deploy the contract successfully.
 		(set_local $exit_code
 			(call $ext_instantiate
@@ -125,6 +129,11 @@
 				(i32.const 8)	;; Length of the buffer with value to transfer.
 				(i32.const 8)	;; Pointer to input data buffer address
 				(i32.const 8)	;; Length of input data buffer
+				(i32.const 16) ;; Pointer to the address output buffer
+				(i32.sub (get_local $sp) (i32.const 4)) ;; Pointer to the address buffer length
+				(i32.const 4294967295) ;; u32 max sentinel value: do not copy output
+				(i32.const 0) ;; Length is ignored in this case
+
 			)
 		)
 
@@ -133,16 +142,9 @@
 			(i32.eq (get_local $exit_code) (i32.const 0x00))
 		)
 
-		;; Check that scratch buffer contains the address of the new contract.
+		;; Check that address has the expected length
 		(call $assert
-			(i32.eq (call $ext_scratch_size) (i32.const 8))
-		)
-
-		;; Copy contract address from scratch buffer into this contract's memory.
-		(call $ext_scratch_read
-			(i32.const 16)		;; The pointer where to store the scratch buffer contents,
-			(i32.const 0)		;; Offset from the start of the scratch buffer.
-			(i32.const 8)		;; Count of bytes to copy.
+			(i32.eq (i32.load (i32.sub (get_local $sp) (i32.const 4))) (i32.const 8))
 		)
 
 		;; Check that balance has been deducted.

frame/contracts/fixtures/destroy_and_transfer.wat

@@ -4,7 +4,7 @@
 	(import "env" "ext_get_storage" (func $ext_get_storage (param i32 i32 i32) (result i32)))
 	(import "env" "ext_set_storage" (func $ext_set_storage (param i32 i32 i32)))
 	(import "env" "ext_call" (func $ext_call (param i32 i32 i64 i32 i32 i32 i32 i32 i32) (result i32)))
-	(import "env" "ext_instantiate" (func $ext_instantiate (param i32 i32 i64 i32 i32 i32 i32) (result i32)))
+	(import "env" "ext_instantiate" (func $ext_instantiate (param i32 i32 i64 i32 i32 i32 i32 i32 i32 i32 i32) (result i32)))
 	(import "env" "memory" (memory 1 1))
 
 	;; [0, 8) Endowment to send when creating contract.
@@ -57,23 +57,22 @@
 					(i32.const 8)	;; Length of the buffer with value to transfer.
 					(i32.const 0)	;; Pointer to input data buffer address
 					(i32.const 0)	;; Length of input data buffer
+					(i32.const 80)	;; Buffer where to store address of new contratc
+					(i32.const 88)	;; Pointer to the length of the buffer
+					(i32.const 4294967295) ;; u32 max sentinel value: do not copy output
+					(i32.const 0) ;; Length is ignored in this cas
 				)
 				(i32.const 0)
 			)
 		)
 
-		;; Read the address of the instantiated contract into memory.
+		;; Check that address has expected length
 		(call $assert
 			(i32.eq
-				(call $ext_scratch_size)
+				(i32.load (i32.const 88))
 				(i32.const 8)
 			)
 		)
-		(call $ext_scratch_read
-			(i32.const 80)		;; The pointer where to store the scratch buffer contents,
-			(i32.const 0)		;; Offset from the start of the scratch buffer.
-			(i32.const 8)		;; Count of bytes to copy.
-		)
 
 		;; Store the return address.
 		(call $ext_set_storage

frame/contracts/src/wasm/mod.rs

@@ -566,8 +566,8 @@ mod tests {
 	;;    value_len: u32,
 	;;    input_data_ptr: u32,
 	;;    input_data_len: u32,
-	;;    result_ptr: u32,
-	;;	  result_len_ptr: u32
+	;;    output_ptr: u32,
+	;;    output_len_ptr: u32
 	;;) -> u32
 	(import "env" "ext_call" (func $ext_call (param i32 i32 i64 i32 i32 i32 i32 i32 i32) (result i32)))
 	(import "env" "memory" (memory 1 1))
@@ -630,8 +630,13 @@ mod tests {
 	;;     value_len: u32,
 	;;     input_data_ptr: u32,
 	;;     input_data_len: u32,
+	;;     input_data_len: u32,
+	;;     address_ptr: u32,
+	;;     address_len_ptr: u32,
+	;;     output_ptr: u32,
+	;;     output_len_ptr: u32
 	;; ) -> u32
-	(import "env" "ext_instantiate" (func $ext_instantiate (param i32 i32 i64 i32 i32 i32 i32) (result i32)))
+	(import "env" "ext_instantiate" (func $ext_instantiate (param i32 i32 i64 i32 i32 i32 i32 i32 i32 i32 i32) (result i32)))
 	(import "env" "memory" (memory 1 1))
 	(func (export "call")
 		(drop
@@ -643,6 +648,10 @@ mod tests {
 				(i32.const 8)    ;; Length of the buffer with value to transfer
 				(i32.const 12)   ;; Pointer to input data buffer address
 				(i32.const 4)    ;; Length of input data buffer
+				(i32.const 4294967295) ;; u32 max value is the sentinel value: do not copy output
+				(i32.const 0) ;; Length is ignored in this case
+				(i32.const 4294967295) ;; u32 max value is the sentinel value: do not copy output
+				(i32.const 0) ;; Length is ignored in this case
 			)
 		)
 	)
@@ -677,7 +686,7 @@ mod tests {
 				code_hash: [0x11; 32].into(),
 				endowment: 3,
 				data: vec![1, 2, 3, 4],
-				gas_left: 9973500000,
+				gas_left: 9971500000,
 			}]
 		);
 	}
@@ -733,8 +742,8 @@ mod tests {
 	;;    value_len: u32,
 	;;    input_data_ptr: u32,
 	;;    input_data_len: u32,
-	;;    result_ptr: u32,
-	;;	  result_len_ptr: u32
+	;;    output_ptr: u32,
+	;;    output_len_ptr: u32
 	;;) -> u32
 	(import "env" "ext_call" (func $ext_call (param i32 i32 i64 i32 i32 i32 i32 i32 i32) (result i32)))
 	(import "env" "memory" (memory 1 1))

frame/contracts/src/wasm/runtime.rs

@@ -526,8 +526,8 @@ define_env!(Env, <E: Ext>,
 		value_len: u32,
 		input_data_ptr: u32,
 		input_data_len: u32,
-		result_ptr: u32,
-		result_len_ptr: u32
+		output_ptr: u32,
+		output_len_ptr: u32
 	) -> u32 => {
 		let callee: <<E as Ext>::T as frame_system::Trait>::AccountId =
 			read_sandbox_memory_as(ctx, callee_ptr, callee_len)?;
@@ -558,7 +558,7 @@ define_env!(Env, <E: Ext>,
 
 		match call_outcome {
 			Ok(output) => {
-				write_sandbox_output(ctx, result_ptr, result_len_ptr, &output.data)?;
+				write_sandbox_output(ctx, output_ptr, output_len_ptr, &output.data)?;
 				Ok(output.status.into())
 			},
 			Err(_) => {
@@ -610,16 +610,16 @@ define_env!(Env, <E: Ext>,
 		value_ptr: u32,
 		value_len: u32,
 		input_data_ptr: u32,
-		input_data_len: u32
+		input_data_len: u32,
+		address_ptr: u32,
+		address_len_ptr: u32,
+		output_ptr: u32,
+		output_len_ptr: u32
 	) -> u32 => {
 		let code_hash: CodeHash<<E as Ext>::T> =
 			read_sandbox_memory_as(ctx, code_hash_ptr, code_hash_len)?;
-		let value: BalanceOf<<E as Ext>::T> =
-			read_sandbox_memory_as(ctx, value_ptr, value_len)?;
-
-		// Read input data into the scratch buffer, then take ownership of it.
-		read_sandbox_memory_into_scratch(ctx, input_data_ptr, input_data_len)?;
-		let input_data = mem::replace(&mut ctx.scratch_buf, Vec::new());
+		let value: BalanceOf<<E as Ext>::T> = read_sandbox_memory_as(ctx, value_ptr, value_len)?;
+		let input_data = read_sandbox_memory(ctx, input_data_ptr, input_data_len)?;
 
 		let nested_gas_limit = if gas == 0 {
 			ctx.gas_meter.gas_left()
@@ -644,18 +644,13 @@ define_env!(Env, <E: Ext>,
 		});
 		match instantiate_outcome {
 			Ok((address, output)) => {
-				let is_success = output.is_success();
-				ctx.scratch_buf = output.data;
-				ctx.scratch_buf.clear();
-				if is_success {
-					// Write the address to the scratch buffer.
-					address.encode_to(&mut ctx.scratch_buf);
+				if output.is_success() {
+					write_sandbox_output(ctx, address_ptr, address_len_ptr, &address.encode())?;
+					write_sandbox_output(ctx, output_ptr, output_len_ptr, &output.data)?;
 				}
 				Ok(output.status.into())
 			},
-			Err(buffer) => {
-				ctx.scratch_buf = buffer;
-				ctx.scratch_buf.clear();
+			Err(_) => {
 				Ok(TRAP_RETURN_CODE)
 			},
 		}