From cf20ecae9f9572d598c3655f1c5dae35a9f4c548 Mon Sep 17 00:00:00 2001
From: Aleksey Kladov <aleksey.kladov@gmail.com>
Date: Wed, 9 Jan 2019 22:51:05 +0300
Subject: [PATCH] unwind on cancel

---
 Cargo.lock              |  8 +++-----
 Cargo.toml              |  1 +
 crates/ra_db/src/lib.rs | 22 ++++++++++++++++------
 3 files changed, 20 insertions(+), 11 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index b3172dc2837..d2d37f0c7a6 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -661,7 +661,7 @@ dependencies = [
  "ra_syntax 0.1.0",
  "relative-path 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-hash 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "salsa 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "salsa 0.9.1",
  "test_utils 0.1.0",
 ]
 
@@ -680,7 +680,7 @@ dependencies = [
  "ra_syntax 0.1.0",
  "relative-path 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-hash 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "salsa 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "salsa 0.9.1",
  "test_utils 0.1.0",
 ]
 
@@ -700,7 +700,7 @@ dependencies = [
  "rayon 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "relative-path 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-hash 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "salsa 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "salsa 0.9.1",
  "test_utils 0.1.0",
  "unicase 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -1030,7 +1030,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
 name = "salsa"
 version = "0.9.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "derive-new 0.5.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "indexmap 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1587,7 +1586,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum rusty-fork 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "9591f190d2852720b679c21f66ad929f9f1d7bb09d1193c26167586029d8489c"
 "checksum ryu 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)" = "eb9e9b8cde282a9fe6a42dd4681319bfb63f121b8a8ee9439c6f4107e58a46f7"
 "checksum safemem 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "8dca453248a96cb0749e36ccdfe2b0b4e54a61bfef89fb97ec621eb8e0a93dd9"
-"checksum salsa 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)" = "442ef4acdb48c0e24ddaf4f3b62555af2d1da7047f2f26acd54ae73010aa0c02"
 "checksum same-file 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "8f20c4be53a8a1ff4c1f1b2bd14570d2f634628709752f0702ecdd2b3f9a5267"
 "checksum scopeguard 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "94258f53601af11e6a49f722422f6e3425c52b06245a5cf9bc09908b174f5e27"
 "checksum semver 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "1d7eb9ef2c18661902cc47e535f9bc51b78acd254da71d375c2f6720d9a40403"
diff --git a/Cargo.toml b/Cargo.toml
index 1cf83dfa896..57896078e3a 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -7,3 +7,4 @@ debug = true
 
 [patch.'crates-io']
 cargo_metadata = { git = "https://github.com/oli-obk/cargo_metadata.git", rev="f73e27b24e" }
+salsa = { path = "/home/matklad/projects/salsa" }
diff --git a/crates/ra_db/src/lib.rs b/crates/ra_db/src/lib.rs
index fb8ea249654..abe6430fb04 100644
--- a/crates/ra_db/src/lib.rs
+++ b/crates/ra_db/src/lib.rs
@@ -5,6 +5,8 @@ mod input;
 mod loc2id;
 pub mod mock;
 
+use std::panic;
+
 use ra_syntax::{TextUnit, TextRange, SourceFile, TreePtr};
 
 pub use crate::{
@@ -18,13 +20,21 @@ pub use crate::{
     loc2id::LocationIntener,
 };
 
-pub trait BaseDatabase: salsa::Database {
+pub trait BaseDatabase: salsa::Database + panic::RefUnwindSafe {
     fn check_canceled(&self) -> Cancelable<()> {
-        if self.salsa_runtime().is_current_revision_canceled() {
-            Err(Canceled::new())
-        } else {
-            Ok(())
-        }
+        self.salsa_runtime()
+            .unwind_if_current_revision_is_canceled();
+        Ok(())
+    }
+
+    fn catch_canceled<F: FnOnce(&Self) -> T + panic::UnwindSafe, T>(
+        &self,
+        f: F,
+    ) -> Result<T, Canceled> {
+        panic::catch_unwind(|| f(self)).map_err(|err| match err.downcast::<salsa::Canceled>() {
+            Ok(_) => Canceled::new(),
+            Err(payload) => panic::resume_unwind(payload),
+        })
     }
 }