From 116bc6dd76924d5769f88a7a9674caa872c1dbaf Mon Sep 17 00:00:00 2001
From: Smitty <me@smitop.com>
Date: Thu, 13 May 2021 10:20:51 -0400
Subject: [PATCH] Check for inline assembly in THIR unsafeck

---
 .../rustc_mir_build/src/check_unsafety.rs     |  4 +++-
 src/test/ui/unsafe/inline_asm.mir.stderr      | 20 +++++++++++++++++++
 src/test/ui/unsafe/inline_asm.rs              | 10 ++++++++++
 src/test/ui/unsafe/inline_asm.thir.stderr     | 20 +++++++++++++++++++
 4 files changed, 53 insertions(+), 1 deletion(-)
 create mode 100644 src/test/ui/unsafe/inline_asm.mir.stderr
 create mode 100644 src/test/ui/unsafe/inline_asm.rs
 create mode 100644 src/test/ui/unsafe/inline_asm.thir.stderr

diff --git a/compiler/rustc_mir_build/src/check_unsafety.rs b/compiler/rustc_mir_build/src/check_unsafety.rs
index 933362578f9..83288fa541e 100644
--- a/compiler/rustc_mir_build/src/check_unsafety.rs
+++ b/compiler/rustc_mir_build/src/check_unsafety.rs
@@ -153,6 +153,9 @@ impl<'thir, 'tcx> Visitor<'thir, 'tcx> for UnsafetyVisitor<'tcx> {
                     self.requires_unsafe(expr.span, CallToUnsafeFunction);
                 }
             }
+            ExprKind::InlineAsm { .. } | ExprKind::LlvmInlineAsm { .. } => {
+                self.requires_unsafe(expr.span, UseOfInlineAssembly);
+            }
             _ => {}
         }
 
@@ -194,7 +197,6 @@ impl BodyUnsafety {
 #[derive(Clone, Copy, PartialEq)]
 enum UnsafeOpKind {
     CallToUnsafeFunction,
-    #[allow(dead_code)] // FIXME
     UseOfInlineAssembly,
     #[allow(dead_code)] // FIXME
     InitializingTypeWith,
diff --git a/src/test/ui/unsafe/inline_asm.mir.stderr b/src/test/ui/unsafe/inline_asm.mir.stderr
new file mode 100644
index 00000000000..daacd234eb4
--- /dev/null
+++ b/src/test/ui/unsafe/inline_asm.mir.stderr
@@ -0,0 +1,20 @@
+error[E0133]: use of inline assembly is unsafe and requires unsafe function or block
+  --> $DIR/inline_asm.rs:8:5
+   |
+LL |     asm!("nop");
+   |     ^^^^^^^^^^^^ use of inline assembly
+   |
+   = note: inline assembly is entirely unchecked and can cause undefined behavior
+
+error[E0133]: use of inline assembly is unsafe and requires unsafe function or block
+  --> $DIR/inline_asm.rs:9:5
+   |
+LL |     llvm_asm!("nop");
+   |     ^^^^^^^^^^^^^^^^^ use of inline assembly
+   |
+   = note: inline assembly is entirely unchecked and can cause undefined behavior
+   = note: this error originates in the macro `llvm_asm` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0133`.
diff --git a/src/test/ui/unsafe/inline_asm.rs b/src/test/ui/unsafe/inline_asm.rs
new file mode 100644
index 00000000000..d002d0e701a
--- /dev/null
+++ b/src/test/ui/unsafe/inline_asm.rs
@@ -0,0 +1,10 @@
+// revisions: mir thir
+// [thir]compile-flags: -Z thir-unsafeck
+
+#![feature(llvm_asm)]
+#![feature(asm)]
+
+fn main() {
+    asm!("nop"); //~ ERROR use of inline assembly is unsafe and requires unsafe function or block
+    llvm_asm!("nop"); //~ ERROR use of inline assembly is unsafe and requires unsafe function or block
+}
diff --git a/src/test/ui/unsafe/inline_asm.thir.stderr b/src/test/ui/unsafe/inline_asm.thir.stderr
new file mode 100644
index 00000000000..daacd234eb4
--- /dev/null
+++ b/src/test/ui/unsafe/inline_asm.thir.stderr
@@ -0,0 +1,20 @@
+error[E0133]: use of inline assembly is unsafe and requires unsafe function or block
+  --> $DIR/inline_asm.rs:8:5
+   |
+LL |     asm!("nop");
+   |     ^^^^^^^^^^^^ use of inline assembly
+   |
+   = note: inline assembly is entirely unchecked and can cause undefined behavior
+
+error[E0133]: use of inline assembly is unsafe and requires unsafe function or block
+  --> $DIR/inline_asm.rs:9:5
+   |
+LL |     llvm_asm!("nop");
+   |     ^^^^^^^^^^^^^^^^^ use of inline assembly
+   |
+   = note: inline assembly is entirely unchecked and can cause undefined behavior
+   = note: this error originates in the macro `llvm_asm` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0133`.