Merge pull request #1668 from RustPython/coolreader18/exc-ser

Make PyBaseExceptionRef serializable and use it to improve WASM errors
2020-01-11 17:14:43 -06:00
parent bc0baa484a c5264c942d
commit bb456963e4
7 changed files with 189 additions and 104 deletions
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -30,6 +30,11 @@ dependencies = [
 "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]

+[[package]]
+name = "anyhow"
+version = "1.0.26"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "arr_macro"
 version = "0.1.2"
@@ -208,7 +213,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"

 [[package]]
 name = "bumpalo"
-version = "2.6.0"
+version = "3.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"

 [[package]]
@@ -259,12 +264,12 @@ name = "chrono"
 version = "0.4.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "js-sys 0.3.28 (registry+https://github.com/rust-lang/crates.io-index)",
+ "js-sys 0.3.35 (registry+https://github.com/rust-lang/crates.io-index)",
 "libc 0.2.66 (registry+https://github.com/rust-lang/crates.io-index)",
 "num-integer 0.1.41 (registry+https://github.com/rust-lang/crates.io-index)",
 "num-traits 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
 "time 0.1.42 (registry+https://github.com/rust-lang/crates.io-index)",
- "wasm-bindgen 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasm-bindgen 0.2.58 (registry+https://github.com/rust-lang/crates.io-index)",
 ]

 [[package]]
@@ -632,10 +637,10 @@ source = "registry+https://github.com/rust-lang/crates.io-index"

 [[package]]
 name = "js-sys"
-version = "0.3.28"
+version = "0.3.35"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "wasm-bindgen 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasm-bindgen 0.2.58 (registry+https://github.com/rust-lang/crates.io-index)",
 ]

 [[package]]
@@ -1394,7 +1399,7 @@ dependencies = [
 "unic-common 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "unicode-casing 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "unicode_names2 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "wasm-bindgen 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasm-bindgen 0.2.58 (registry+https://github.com/rust-lang/crates.io-index)",
 "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
 "wtf8 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -1405,15 +1410,15 @@ version = "0.1.0-pre-alpha.2"
 dependencies = [
 "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
 "futures 0.1.29 (registry+https://github.com/rust-lang/crates.io-index)",
- "js-sys 0.3.28 (registry+https://github.com/rust-lang/crates.io-index)",
+ "js-sys 0.3.35 (registry+https://github.com/rust-lang/crates.io-index)",
 "rustpython-compiler 0.1.1",
 "rustpython-parser 0.1.1",
 "rustpython-vm 0.1.1",
 "serde 1.0.101 (registry+https://github.com/rust-lang/crates.io-index)",
 "serde-wasm-bindgen 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
- "wasm-bindgen 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasm-bindgen 0.2.58 (registry+https://github.com/rust-lang/crates.io-index)",
 "wasm-bindgen-futures 0.3.27 (registry+https://github.com/rust-lang/crates.io-index)",
- "web-sys 0.3.28 (registry+https://github.com/rust-lang/crates.io-index)",
+ "web-sys 0.3.35 (registry+https://github.com/rust-lang/crates.io-index)",
 ]

 [[package]]
@@ -1464,9 +1469,9 @@ version = "0.1.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "fnv 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "js-sys 0.3.28 (registry+https://github.com/rust-lang/crates.io-index)",
+ "js-sys 0.3.35 (registry+https://github.com/rust-lang/crates.io-index)",
 "serde 1.0.101 (registry+https://github.com/rust-lang/crates.io-index)",
- "wasm-bindgen 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasm-bindgen 0.2.58 (registry+https://github.com/rust-lang/crates.io-index)",
 ]

 [[package]]
@@ -2046,25 +2051,25 @@ source = "registry+https://github.com/rust-lang/crates.io-index"

 [[package]]
 name = "wasm-bindgen"
-version = "0.2.51"
+version = "0.2.58"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
- "wasm-bindgen-macro 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasm-bindgen-macro 0.2.58 (registry+https://github.com/rust-lang/crates.io-index)",
 ]

 [[package]]
 name = "wasm-bindgen-backend"
-version = "0.2.51"
+version = "0.2.58"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "bumpalo 2.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bumpalo 3.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
 "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
 "proc-macro2 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
 "quote 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
 "syn 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
- "wasm-bindgen-shared 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasm-bindgen-shared 0.2.58 (registry+https://github.com/rust-lang/crates.io-index)",
 ]

 [[package]]
@@ -2074,62 +2079,62 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
 "futures 0.1.29 (registry+https://github.com/rust-lang/crates.io-index)",
- "js-sys 0.3.28 (registry+https://github.com/rust-lang/crates.io-index)",
- "wasm-bindgen 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
- "web-sys 0.3.28 (registry+https://github.com/rust-lang/crates.io-index)",
+ "js-sys 0.3.35 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasm-bindgen 0.2.58 (registry+https://github.com/rust-lang/crates.io-index)",
+ "web-sys 0.3.35 (registry+https://github.com/rust-lang/crates.io-index)",
 ]

 [[package]]
 name = "wasm-bindgen-macro"
-version = "0.2.51"
+version = "0.2.58"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "quote 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "wasm-bindgen-macro-support 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasm-bindgen-macro-support 0.2.58 (registry+https://github.com/rust-lang/crates.io-index)",
 ]

 [[package]]
 name = "wasm-bindgen-macro-support"
-version = "0.2.51"
+version = "0.2.58"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "proc-macro2 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
 "quote 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
 "syn 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
- "wasm-bindgen-backend 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
- "wasm-bindgen-shared 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasm-bindgen-backend 0.2.58 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasm-bindgen-shared 0.2.58 (registry+https://github.com/rust-lang/crates.io-index)",
 ]

 [[package]]
 name = "wasm-bindgen-shared"
-version = "0.2.51"
+version = "0.2.58"
 source = "registry+https://github.com/rust-lang/crates.io-index"

 [[package]]
 name = "wasm-bindgen-webidl"
-version = "0.2.51"
+version = "0.2.58"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "failure 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "anyhow 1.0.26 (registry+https://github.com/rust-lang/crates.io-index)",
 "heck 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
 "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
 "proc-macro2 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
 "quote 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
 "syn 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
- "wasm-bindgen-backend 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasm-bindgen-backend 0.2.58 (registry+https://github.com/rust-lang/crates.io-index)",
 "weedle 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]

 [[package]]
 name = "web-sys"
-version = "0.3.28"
+version = "0.3.35"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "failure 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
- "js-sys 0.3.28 (registry+https://github.com/rust-lang/crates.io-index)",
+ "anyhow 1.0.26 (registry+https://github.com/rust-lang/crates.io-index)",
+ "js-sys 0.3.35 (registry+https://github.com/rust-lang/crates.io-index)",
 "sourcefile 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "wasm-bindgen 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
- "wasm-bindgen-webidl 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasm-bindgen 0.2.58 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasm-bindgen-webidl 0.2.58 (registry+https://github.com/rust-lang/crates.io-index)",
 ]

 [[package]]
@@ -2186,6 +2191,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum adler32 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "5d2e7343e7fc9de883d1b0341e0b13970f764c14101234857d2ddafa1cb1cac2"
 "checksum aho-corasick 0.7.6 (registry+https://github.com/rust-lang/crates.io-index)" = "58fb5e95d83b38284460a5fda7d6470aa0b8844d283a0b614b8535e880800d2d"
 "checksum ansi_term 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ee49baf6cb617b853aa8d93bf420db2383fab46d314482ca2803b40d5fde979b"
+"checksum anyhow 1.0.26 (registry+https://github.com/rust-lang/crates.io-index)" = "7825f6833612eb2414095684fcf6c635becf3ce97fe48cf6421321e93bfbd53c"
 "checksum arr_macro 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "d262b83f2f573121554ad6e764cd444303df85d86e5fcebc81903ddcf8dd3a97"
 "checksum arr_macro_impl 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "8decbe97ffec939e44228d91e5d0829ceb1616c6ed0984c09df164b1e7ebaafc"
 "checksum arrayref 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)" = "0d382e583f07208808f6b1249e60848879ba3543f57c32277bf52d69c2f0f0ee"
@@ -2208,7 +2214,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum block-padding 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "6d4dc3af3ee2e12f3e5d224e5e1e3d73668abbeb69e566d361f7d5563a4fdf09"
 "checksum bstr 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)" = "8d6c2c5b58ab920a4f5aeaaca34b4488074e8cc7596af94e6f8c6ff247c60245"
 "checksum build_const 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "39092a32794787acd8525ee150305ff051b0aa6cc2abaf193924f5ab05425f39"
-"checksum bumpalo 2.6.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ad807f2fc2bf185eeb98ff3a901bd46dc5ad58163d0fa4577ba0d25674d71708"
+"checksum bumpalo 3.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "5fb8038c1ddc0a5f73787b130f4cc75151e96ed33e417fde765eb5a81e3532f4"
 "checksum byte-tools 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "e3b5ca7a04898ad4bcd41c90c5285445ff5b791899bb1b0abdd2a2aa791211d7"
 "checksum byteorder 0.5.3 (registry+https://github.com/rust-lang/crates.io-index)" = "0fc10e8cc6b2580fda3f36eb6dc5316657f812a3df879a44a66fc9f0fdbc4855"
 "checksum byteorder 1.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "a7c3dd8985a7111efc5c80b44e23ecdd8c007de8ade3b96595387e812b957cf5"
@@ -2261,7 +2267,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum is-macro 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)" = "5f9a8b41b34ff4371fb34c500c9d5a5b39548f51efbc278c4a53195e73961cea"
 "checksum itertools 0.8.2 (registry+https://github.com/rust-lang/crates.io-index)" = "f56a2d0bc861f9165be4eb3442afd3c236d8a98afd426f65d92324ae1091a484"
 "checksum itoa 0.4.4 (registry+https://github.com/rust-lang/crates.io-index)" = "501266b7edd0174f8530248f87f99c88fbe60ca4ef3dd486835b8d8d53136f7f"
-"checksum js-sys 0.3.28 (registry+https://github.com/rust-lang/crates.io-index)" = "2cc9a97d7cec30128fd8b28a7c1f9df1c001ceb9b441e2b755e24130a6b43c79"
+"checksum js-sys 0.3.35 (registry+https://github.com/rust-lang/crates.io-index)" = "7889c7c36282151f6bf465be4700359318aef36baa951462382eae49e9577cf9"
 "checksum keccak 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "67c21572b4949434e4fc1e1978b99c5f77064153c59d998bf13ecd96fb5ecba7"
 "checksum lalrpop 0.17.2 (registry+https://github.com/rust-lang/crates.io-index)" = "64dc3698e75d452867d9bd86f4a723f452ce9d01fe1d55990b79f0c790aa67db"
 "checksum lalrpop-util 0.17.2 (registry+https://github.com/rust-lang/crates.io-index)" = "c277d18683b36349ab5cd030158b54856fca6bb2d5dc5263b06288f486958b7c"
@@ -2410,14 +2416,14 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum version_check 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "914b1a6776c4c929a602fafd8bc742e06365d4bcbe48c30f9cca5824f70dc9dd"
 "checksum void 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6a02e4885ed3bc0f2de90ea6dd45ebcbb66dacffe03547fadbb0eeae2770887d"
 "checksum wasi 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "b89c3ce4ce14bdc6fb6beaf9ec7928ca331de5df7e5ea278375642a2f478570d"
-"checksum wasm-bindgen 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)" = "cd34c5ba0d228317ce388e87724633c57edca3e7531feb4e25e35aaa07a656af"
-"checksum wasm-bindgen-backend 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)" = "927196b315c23eed2748442ba675a4c54a1a079d90d9bdc5ad16ce31cf90b15b"
+"checksum wasm-bindgen 0.2.58 (registry+https://github.com/rust-lang/crates.io-index)" = "5205e9afdf42282b192e2310a5b463a6d1c1d774e30dc3c791ac37ab42d2616c"
+"checksum wasm-bindgen-backend 0.2.58 (registry+https://github.com/rust-lang/crates.io-index)" = "11cdb95816290b525b32587d76419facd99662a07e59d3cdb560488a819d9a45"
 "checksum wasm-bindgen-futures 0.3.27 (registry+https://github.com/rust-lang/crates.io-index)" = "83420b37346c311b9ed822af41ec2e82839bfe99867ec6c54e2da43b7538771c"
-"checksum wasm-bindgen-macro 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)" = "92c2442bf04d89792816650820c3fb407af8da987a9f10028d5317f5b04c2b4a"
-"checksum wasm-bindgen-macro-support 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)" = "9c075d27b7991c68ca0f77fe628c3513e64f8c477d422b859e03f28751b46fc5"
-"checksum wasm-bindgen-shared 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)" = "83d61fe986a7af038dd8b5ec660e5849cbd9f38e7492b9404cc48b2b4df731d1"
-"checksum wasm-bindgen-webidl 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)" = "9b979afb0535fe4749906a674082db1211de8aef466331d43232f63accb7c07c"
-"checksum web-sys 0.3.28 (registry+https://github.com/rust-lang/crates.io-index)" = "c84440699cd02ca23bed6f045ffb1497bc18a3c2628bd13e2093186faaaacf6b"
+"checksum wasm-bindgen-macro 0.2.58 (registry+https://github.com/rust-lang/crates.io-index)" = "574094772ce6921576fb6f2e3f7497b8a76273b6db092be18fc48a082de09dc3"
+"checksum wasm-bindgen-macro-support 0.2.58 (registry+https://github.com/rust-lang/crates.io-index)" = "e85031354f25eaebe78bb7db1c3d86140312a911a106b2e29f9cc440ce3e7668"
+"checksum wasm-bindgen-shared 0.2.58 (registry+https://github.com/rust-lang/crates.io-index)" = "f5e7e61fc929f4c0dddb748b102ebf9f632e2b8d739f2016542b4de2965a9601"
+"checksum wasm-bindgen-webidl 0.2.58 (registry+https://github.com/rust-lang/crates.io-index)" = "ef012a0d93fc0432df126a8eaf547b2dce25a8ce9212e1d3cbeef5c11157975d"
+"checksum web-sys 0.3.35 (registry+https://github.com/rust-lang/crates.io-index)" = "aaf97caf6aa8c2b1dac90faf0db529d9d63c93846cca4911856f78a83cebf53b"
 "checksum weedle 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)" = "3bb43f70885151e629e2a19ce9e50bd730fd436cfd4b666894c9ce4de9141164"
 "checksum winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)" = "8093091eeb260906a183e6ae1abdba2ef5ef2257a21801128899c3fc699229c6"
 "checksum winapi-i686-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
--- a/vm/src/exceptions.rs
+++ b/vm/src/exceptions.rs
@@ -4,12 +4,13 @@ use crate::obj::objstr::{PyString, PyStringRef};
 use crate::obj::objtraceback::PyTracebackRef;
 use crate::obj::objtuple::{PyTuple, PyTupleRef};
 use crate::obj::objtype::{self, PyClass, PyClassRef};
+use crate::py_serde;
 use crate::pyobject::{
    PyClassImpl, PyContext, PyIterable, PyObjectRef, PyRef, PyResult, PyValue, TryFromObject,
    TypeProtocol,
 };
 use crate::types::create_type;
-use crate::vm::VirtualMachine;
+use crate::VirtualMachine;
 use itertools::Itertools;
 use std::cell::{Cell, RefCell};
 use std::fmt;
@@ -245,10 +246,8 @@ pub fn write_exception_inner<W: Write>(
 ) -> io::Result<()> {
    if let Some(tb) = exc.traceback.borrow().clone() {
        writeln!(output, "Traceback (most recent call last):")?;
-        let mut tb = Some(&tb);
-        while let Some(traceback) = tb {
-            write_traceback_entry(output, traceback)?;
-            tb = traceback.next.as_ref();
+        for tb in tb.iter() {
+            write_traceback_entry(output, &tb)?;
        }
    }

@@ -660,3 +659,71 @@ pub fn init(ctx: &PyContext) {
        "reason" => ctx.new_property(make_arg_getter(3)),
    });
 }
+
+pub struct SerializeException<'s> {
+    vm: &'s VirtualMachine,
+    exc: &'s PyBaseExceptionRef,
+}
+
+impl<'s> SerializeException<'s> {
+    pub fn new(vm: &'s VirtualMachine, exc: &'s PyBaseExceptionRef) -> Self {
+        SerializeException { vm, exc }
+    }
+}
+
+impl serde::Serialize for SerializeException<'_> {
+    fn serialize<S: serde::Serializer>(&self, s: S) -> Result<S::Ok, S::Error> {
+        use serde::ser::*;
+
+        let mut struc = s.serialize_struct("PyBaseException", 7)?;
+        struc.serialize_field("exc_type", &self.exc.class().name)?;
+        let tbs = {
+            struct Tracebacks(PyTracebackRef);
+            impl serde::Serialize for Tracebacks {
+                fn serialize<S: serde::Serializer>(&self, s: S) -> Result<S::Ok, S::Error> {
+                    let mut s = s.serialize_seq(None)?;
+                    for tb in self.0.iter() {
+                        s.serialize_element(&*tb)?;
+                    }
+                    s.end()
+                }
+            }
+            self.exc.traceback().map(Tracebacks)
+        };
+        struc.serialize_field("traceback", &tbs)?;
+        struc.serialize_field(
+            "cause",
+            &self.exc.cause().as_ref().map(|e| Self::new(self.vm, e)),
+        )?;
+        struc.serialize_field(
+            "context",
+            &self.exc.context().as_ref().map(|e| Self::new(self.vm, e)),
+        )?;
+        struc.serialize_field("suppress_context", &self.exc.suppress_context.get())?;
+
+        let args = {
+            struct Args<'vm>(&'vm VirtualMachine, PyTupleRef);
+            impl serde::Serialize for Args<'_> {
+                fn serialize<S: serde::Serializer>(&self, s: S) -> Result<S::Ok, S::Error> {
+                    s.collect_seq(
+                        self.1
+                            .as_slice()
+                            .iter()
+                            .map(|arg| py_serde::PyObjectSerializer::new(self.0, arg)),
+                    )
+                }
+            }
+            Args(self.vm, self.exc.args())
+        };
+        struc.serialize_field("args", &args)?;
+
+        let rendered = {
+            let mut rendered = Vec::<u8>::new();
+            write_exception(&mut rendered, self.vm, &self.exc).map_err(S::Error::custom)?;
+            String::from_utf8(rendered).map_err(S::Error::custom)?
+        };
+        struc.serialize_field("rendered", &rendered)?;
+
+        struc.end()
+    }
+}
--- a/vm/src/obj/objtraceback.rs
+++ b/vm/src/obj/objtraceback.rs
@@ -52,6 +52,24 @@ impl PyTraceback {
    }
 }

+impl PyTracebackRef {
+    pub fn iter<'a>(&'a self) -> impl Iterator<Item = PyTracebackRef> + 'a {
+        std::iter::successors(Some(self.clone()), |tb| tb.next.clone())
+    }
+}
+
 pub fn init(context: &PyContext) {
    PyTraceback::extend_class(context, &context.types.traceback_type);
 }
+
+impl serde::Serialize for PyTraceback {
+    fn serialize<S: serde::Serializer>(&self, s: S) -> Result<S::Ok, S::Error> {
+        use serde::ser::SerializeStruct;
+
+        let mut struc = s.serialize_struct("PyTraceback", 3)?;
+        struc.serialize_field("name", &self.frame.code.obj_name)?;
+        struc.serialize_field("lineno", &self.lineno)?;
+        struc.serialize_field("filename", &self.frame.code.source_path)?;
+        struc.end()
+    }
+}
--- a/wasm/demo/src/style.css
+++ b/wasm/demo/src/style.css
@@ -24,6 +24,7 @@ textarea {
    color: tomato;
    margin-top: 10px;
    font-family: monospace;
+    white-space: pre;
 }

 #code-wrapper {
--- a/wasm/lib/src/convert.rs
+++ b/wasm/lib/src/convert.rs
@@ -5,41 +5,38 @@ use wasm_bindgen::{closure::Closure, prelude::*, JsCast};
 use rustpython_vm::exceptions::PyBaseExceptionRef;
 use rustpython_vm::function::PyFuncArgs;
 use rustpython_vm::obj::{objbytes, objtype};
-use rustpython_vm::py_serde;
 use rustpython_vm::pyobject::{ItemProtocol, PyObjectRef, PyResult, PyValue};
 use rustpython_vm::VirtualMachine;
+use rustpython_vm::{exceptions, py_serde};

 use crate::browser_module;
 use crate::vm_class::{stored_vm_from_wasm, WASMVirtualMachine};

+#[wasm_bindgen(inline_js = r"
+export class PyError extends Error {
+    constructor(info) {
+        const msg = info.args[0];
+        if (typeof msg === 'string') super(msg);
+        else super();
+        this.info = info;
+    }
+    get name() { return this.info.exc_type; }
+    get traceback() { return this.info.traceback; }
+    toString() { return this.info.rendered; }
+}
+")]
+extern "C" {
+    pub type PyError;
+    #[wasm_bindgen(constructor)]
+    fn new(info: JsValue) -> PyError;
+}
+
 pub fn py_err_to_js_err(vm: &VirtualMachine, py_err: &PyBaseExceptionRef) -> JsValue {
-    macro_rules! map_exceptions {
-        ($py_exc:ident, $msg:expr, { $($py_exc_ty:expr => $js_err_new:expr),*$(,)? }) => {
-            $(if objtype::isinstance($py_exc, $py_exc_ty) {
-                JsValue::from($js_err_new($msg))
-            } else)* {
-                JsValue::from(js_sys::Error::new($msg))
-            }
-        };
+    let res = serde_wasm_bindgen::to_value(&exceptions::SerializeException::new(vm, py_err));
+    match res {
+        Ok(err_info) => PyError::new(err_info).into(),
+        Err(e) => e.into(),
    }
-    let msg = match vm.to_str(py_err.as_object()) {
-        Ok(msg) => msg,
-        Err(_) => return js_sys::Error::new("error getting error").into(),
-    };
-    let js_err = map_exceptions!(py_err, msg.as_str(), {
-        // TypeError is sort of a catch-all for "this value isn't what I thought it was like"
-        &vm.ctx.exceptions.type_error => js_sys::TypeError::new,
-        &vm.ctx.exceptions.value_error => js_sys::TypeError::new,
-        &vm.ctx.exceptions.index_error => js_sys::TypeError::new,
-        &vm.ctx.exceptions.key_error => js_sys::TypeError::new,
-        &vm.ctx.exceptions.attribute_error => js_sys::TypeError::new,
-        &vm.ctx.exceptions.name_error => js_sys::ReferenceError::new,
-        &vm.ctx.exceptions.syntax_error => js_sys::SyntaxError::new,
-    });
-    if let Some(tb) = py_err.traceback() {
-        let _ = Reflect::set(&js_err, &"row".into(), &(tb.lineno as u32).into());
-    }
-    js_err
 }

 pub fn js_py_typeerror(vm: &VirtualMachine, js_err: JsValue) -> PyBaseExceptionRef {
--- a/wasm/lib/src/lib.rs
+++ b/wasm/lib/src/lib.rs
@@ -18,6 +18,7 @@ use rustpython_compiler::compile::Mode;
 use std::panic;
 use wasm_bindgen::prelude::*;

+pub use crate::convert::PyError;
 pub use crate::vm_class::*;

 const PY_EVAL_VM_ID: &str = "__py_eval_vm";
@@ -45,10 +46,6 @@ pub fn setup_console_error() {
    std::panic::set_hook(Box::new(panic_hook));
 }

-// Hack to comment out wasm-bindgen's generated typescript definitons
-#[wasm_bindgen(typescript_custom_section)]
-const TS_CMT_START: &'static str = "/*";
-
 fn run_py(source: &str, options: Option<Object>, mode: Mode) -> Result<JsValue, JsValue> {
    let vm = VMStore::init(PY_EVAL_VM_ID.into(), Some(true));
    let options = options.unwrap_or_else(Object::new);
@@ -68,9 +65,9 @@ fn run_py(source: &str, options: Option<Object>, mode: Mode) -> Result<JsValue,
    if let Some(js_vars) = js_vars {
        vm.add_to_scope("js_vars".into(), js_vars.into())?;
    }
-    vm.run(source, mode)
+    vm.run(source, mode, None)
 }
-#[wasm_bindgen(js_name = pyEval)]
+
 /// Evaluate Python code
 ///
 /// ```js
@@ -87,12 +84,11 @@ fn run_py(source: &str, options: Option<Object>, mode: Mode) -> Result<JsValue,
 /// -   `stdout?`: `"console" | ((out: string) => void) | null`: A function to replace the
 ///     native print native print function, and it will be `console.log` when giving
 ///     `undefined` or "console", and it will be a dumb function when giving null.
-
+#[wasm_bindgen(js_name = pyEval)]
 pub fn eval_py(source: &str, options: Option<Object>) -> Result<JsValue, JsValue> {
    run_py(source, options, Mode::Eval)
 }

-#[wasm_bindgen(js_name = pyExec)]
 /// Evaluate Python code
 ///
 /// ```js
@@ -102,11 +98,11 @@ pub fn eval_py(source: &str, options: Option<Object>) -> Result<JsValue, JsValue
 /// `code`: `string`: The Python code to run in exec mode
 ///
 /// `options`: The options are the same as eval mode
-pub fn exec_py(source: &str, options: Option<Object>) {
-    let _ = run_py(source, options, Mode::Exec);
+#[wasm_bindgen(js_name = pyExec)]
+pub fn exec_py(source: &str, options: Option<Object>) -> Result<(), JsValue> {
+    run_py(source, options, Mode::Exec).map(drop)
 }

-#[wasm_bindgen(js_name = pyExecSingle)]
 /// Evaluate Python code
 ///
 /// ```js
@@ -116,17 +112,7 @@ pub fn exec_py(source: &str, options: Option<Object>) {
 /// `code`: `string`: The Python code to run in exec single mode
 ///
 /// `options`: The options are the same as eval mode
+#[wasm_bindgen(js_name = pyExecSingle)]
 pub fn exec_single_py(source: &str, options: Option<Object>) -> Result<JsValue, JsValue> {
    run_py(source, options, Mode::Single)
 }
-
-#[wasm_bindgen(typescript_custom_section)]
-const TYPESCRIPT_DEFS: &'static str = r#"
-*/
-export interface PyEvalOptions {
-    stdout: (out: string) => void;
-    vars: { [key: string]: any };
-}
-
-export function pyEval(code: string, options?: PyEvalOptions): any;
-"#;
--- a/wasm/lib/src/vm_class.rs
+++ b/wasm/lib/src/vm_class.rs
@@ -278,13 +278,19 @@ impl WASMVirtualMachine {
        })?
    }

-    pub(crate) fn run(&self, source: &str, mode: compile::Mode) -> Result<JsValue, JsValue> {
+    pub(crate) fn run(
+        &self,
+        source: &str,
+        mode: compile::Mode,
+        source_path: Option<String>,
+    ) -> Result<JsValue, JsValue> {
        self.assert_valid()?;
        self.with_unchecked(
            |StoredVirtualMachine {
                 ref vm, ref scope, ..
             }| {
-                let code = vm.compile(source, mode, "<wasm>".to_string());
+                let source_path = source_path.unwrap_or_else(|| "<wasm>".to_string());
+                let code = vm.compile(source, mode, source_path);
                let code = code.map_err(|err| {
                    let js_err = SyntaxError::new(&format!("Error parsing Python code: {}", err));
                    let _ =
@@ -302,16 +308,20 @@ impl WASMVirtualMachine {
        )
    }

-    pub fn exec(&self, source: &str) -> Result<JsValue, JsValue> {
-        self.run(source, compile::Mode::Exec)
+    pub fn exec(&self, source: &str, source_path: Option<String>) -> Result<JsValue, JsValue> {
+        self.run(source, compile::Mode::Exec, source_path)
    }

-    pub fn eval(&self, source: &str) -> Result<JsValue, JsValue> {
-        self.run(source, compile::Mode::Eval)
+    pub fn eval(&self, source: &str, source_path: Option<String>) -> Result<JsValue, JsValue> {
+        self.run(source, compile::Mode::Eval, source_path)
    }

    #[wasm_bindgen(js_name = execSingle)]
-    pub fn exec_single(&self, source: &str) -> Result<JsValue, JsValue> {
-        self.run(source, compile::Mode::Single)
+    pub fn exec_single(
+        &self,
+        source: &str,
+        source_path: Option<String>,
+    ) -> Result<JsValue, JsValue> {
+        self.run(source, compile::Mode::Single, source_path)
    }
 }