From bdf426afe757ed2160c9d8ead9081a07751b9efb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Esteban=20K=C3=BCber?= <esteban@kuber.com.ar>
Date: Sun, 9 Aug 2020 15:12:59 -0700
Subject: [PATCH] Do not ICE when lowering invalid extern fn with bodies
Fix #75283.
---
src/librustc_ast_lowering/lib.rs | 4 +++-
src/test/ui/issues/issue-75283.rs | 6 ++++++
src/test/ui/issues/issue-75283.stderr | 18 ++++++++++++++++++
3 files changed, 27 insertions(+), 1 deletion(-)
create mode 100644 src/test/ui/issues/issue-75283.rs
create mode 100644 src/test/ui/issues/issue-75283.stderr
diff --git a/src/librustc_ast_lowering/lib.rs b/src/librustc_ast_lowering/lib.rs
index 9df7ad2a9acf4..f2a59cccf9d8c 100644
--- a/src/librustc_ast_lowering/lib.rs
+++ b/src/librustc_ast_lowering/lib.rs
@@ -574,7 +574,9 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
.resolver
.trait_map()
.iter()
- .map(|(&k, v)| (self.node_id_to_hir_id[k].unwrap(), v.clone()))
+ .filter_map(|(&k, v)| {
+ self.node_id_to_hir_id.get(k).and_then(|id| id.as_ref()).map(|id| (*id, v.clone()))
+ })
.collect();
let mut def_id_to_hir_id = IndexVec::default();
diff --git a/src/test/ui/issues/issue-75283.rs b/src/test/ui/issues/issue-75283.rs
new file mode 100644
index 0000000000000..d556132e47ffd
--- /dev/null
+++ b/src/test/ui/issues/issue-75283.rs
@@ -0,0 +1,6 @@
+extern "C" {
+ fn lol() { //~ ERROR incorrect function inside `extern` block
+ println!("");
+ }
+}
+fn main() {}
diff --git a/src/test/ui/issues/issue-75283.stderr b/src/test/ui/issues/issue-75283.stderr
new file mode 100644
index 0000000000000..da3800affc05a
--- /dev/null
+++ b/src/test/ui/issues/issue-75283.stderr
@@ -0,0 +1,18 @@
+error: incorrect function inside `extern` block
+ --> $DIR/issue-75283.rs:2:8
+ |
+LL | extern "C" {
+ | ---------- `extern` blocks define existing foreign functions and functions inside of them cannot have a body
+LL | fn lol() {
+ | ________^^^___-
+ | | |
+ | | cannot have a body
+LL | | println!("");
+LL | | }
+ | |_____- help: remove the invalid body: `;`
+ |
+ = help: you might have meant to write a function accessible through FFI, which can be done by writing `extern fn` outside of the `extern` block
+ = note: for more information, visit https://doc.rust-lang.org/std/keyword.extern.html
+
+error: aborting due to previous error
+