From c983efe895c6ef3aee0e7f6fe035ea14073c5924 Mon Sep 17 00:00:00 2001
From: Wei Tang <accounts@that.world>
Date: Sat, 21 Apr 2018 17:41:09 +0800
Subject: [PATCH] Return error in case eth_call returns VM errors (#8448)

* Add VMError generator

* Return executed exceptions in eth_call
---
 rpc/src/v1/helpers/errors.rs | 16 ++++++++++++++++
 rpc/src/v1/impls/eth.rs      |  8 +++++++-
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/rpc/src/v1/helpers/errors.rs b/rpc/src/v1/helpers/errors.rs
index 4e5fa2fb7..acff79664 100644
--- a/rpc/src/v1/helpers/errors.rs
+++ b/rpc/src/v1/helpers/errors.rs
@@ -24,6 +24,7 @@ use jsonrpc_core::{futures, Error, ErrorCode, Value};
 use rlp::DecoderError;
 use transaction::Error as TransactionError;
 use ethcore_private_tx::Error as PrivateTransactionError;
+use vm::Error as VMError;
 
 mod codes {
 	// NOTE [ToDr] Codes from [-32099, -32000]
@@ -375,6 +376,21 @@ pub fn call(error: CallError) -> Error {
 	}
 }
 
+pub fn vm(error: &VMError, output: &[u8]) -> Error {
+	use rustc_hex::ToHex;
+
+	let data = match error {
+		&VMError::Reverted => format!("{} 0x{}", VMError::Reverted, output.to_hex()),
+		error => format!("{}", error),
+	};
+
+	Error {
+		code: ErrorCode::ServerError(codes::EXECUTION_ERROR),
+		message: "VM execution error.".into(),
+		data: Some(Value::String(data)),
+	}
+}
+
 pub fn unknown_block() -> Error {
 	Error {
 		code: ErrorCode::InvalidParams,
diff --git a/rpc/src/v1/impls/eth.rs b/rpc/src/v1/impls/eth.rs
index c894f16df..a7ff4916d 100644
--- a/rpc/src/v1/impls/eth.rs
+++ b/rpc/src/v1/impls/eth.rs
@@ -859,8 +859,14 @@ impl<C, SN: ?Sized, S: ?Sized, M, EM, T: StateInfo + 'static> Eth for EthClient<
 		let result = self.client.call(&signed, Default::default(), &mut state, &header);
 
 		Box::new(future::done(result
-			.map(|b| b.output.into())
 			.map_err(errors::call)
+			.and_then(|executed| {
+				match executed.exception {
+					Some(ref exception) => Err(errors::vm(exception, &executed.output)),
+					None => Ok(executed)
+				}
+			})
+			.map(|b| b.output.into())
 		))
 	}