Selectively disable sanitizer instrumentation

Add `no_sanitize` attribute that allows to opt out from sanitizer
instrumentation in an annotated function.

src/test/codegen/sanitizer-no-sanitize-inlining.rs

@@ -0,0 +1,32 @@
+// Verifies that no_sanitize attribute prevents inlining when
+// given sanitizer is enabled, but has no effect on inlining otherwise.
+//
+// needs-sanitizer-support
+// only-x86_64
+//
+// revisions: ASAN LSAN
+//
+//[ASAN] compile-flags: -Zsanitizer=address -C opt-level=3 -Z mir-opt-level=3
+//[LSAN] compile-flags: -Zsanitizer=leak    -C opt-level=3 -Z mir-opt-level=3
+
+#![crate_type="lib"]
+#![feature(no_sanitize)]
+
+// ASAN-LABEL: define void @test
+// ASAN:         tail call fastcc void @random_inline
+// ASAN:       }
+//
+// LSAN-LABEL: define void @test
+// LSAN-NO:      call
+// LSAN:       }
+#[no_mangle]
+pub fn test(n: &mut u32) {
+    random_inline(n);
+}
+
+#[no_sanitize(address)]
+#[inline]
+#[no_mangle]
+pub fn random_inline(n: &mut u32) {
+    *n = 42;
+}

src/test/codegen/sanitizer-no-sanitize.rs

@@ -0,0 +1,29 @@
+// Verifies that no_sanitze attribute can be used to
+// selectively disable sanitizer instrumentation.
+//
+// needs-sanitizer-support
+// compile-flags: -Zsanitizer=address
+
+#![crate_type="lib"]
+#![feature(no_sanitize)]
+
+// CHECK-LABEL: ; sanitizer_no_sanitize::unsanitized
+// CHECK-NEXT:  ; Function Attrs:
+// CHECK-NOT:   sanitize_address
+// CHECK:       start:
+// CHECK-NOT:   call void @__asan_report_load
+// CHECK:       }
+#[no_sanitize(address)]
+pub fn unsanitized(b: &mut u8) -> u8 {
+    *b
+}
+
+// CHECK-LABEL: ; sanitizer_no_sanitize::sanitized
+// CHECK-NEXT:  ; Function Attrs:
+// CHECK:       sanitize_address
+// CHECK:       start:
+// CHECK:       call void @__asan_report_load
+// CHECK:       }
+pub fn sanitized(b: &mut u8) -> u8 {
+    *b
+}

src/test/ui/feature-gates/feature-gate-no_sanitize.rs

@@ -0,0 +1,4 @@
+#[no_sanitize(address)]
+//~^ the `#[no_sanitize]` attribute is an experimental feature
+fn main() {
+}

src/test/ui/feature-gates/feature-gate-no_sanitize.stderr

@@ -0,0 +1,12 @@
+error[E0658]: the `#[no_sanitize]` attribute is an experimental feature
+  --> $DIR/feature-gate-no_sanitize.rs:1:1
+   |
+LL | #[no_sanitize(address)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/39699
+   = help: add `#![feature(no_sanitize)]` to the crate attributes to enable
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0658`.

src/test/ui/invalid/invalid-no-sanitize.rs

@@ -0,0 +1,5 @@
+#![feature(no_sanitize)]
+
+#[no_sanitize(brontosaurus)] //~ ERROR invalid argument
+fn main() {
+}

src/test/ui/invalid/invalid-no-sanitize.stderr

@@ -0,0 +1,10 @@
+error: invalid argument for `no_sanitize`
+  --> $DIR/invalid-no-sanitize.rs:3:15
+   |
+LL | #[no_sanitize(brontosaurus)]
+   |               ^^^^^^^^^^^^
+   |
+   = note: expected one of: `address`, `memory` or `thread`
+
+error: aborting due to previous error
+

src/test/ui/sanitize-inline-always.rs

@@ -0,0 +1,15 @@
+// check-pass
+
+#![feature(no_sanitize)]
+
+#[inline(always)]
+//~^ NOTE inlining requested here
+#[no_sanitize(address)]
+//~^ WARN will have no effect after inlining
+//~| NOTE on by default
+fn x() {
+}
+
+fn main() {
+    x()
+}

src/test/ui/sanitize-inline-always.stderr

@@ -0,0 +1,13 @@
+warning: `no_sanitize` will have no effect after inlining
+  --> $DIR/sanitize-inline-always.rs:7:1
+   |
+LL | #[no_sanitize(address)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: `#[warn(inline_no_sanitize)]` on by default
+note: inlining requested here
+  --> $DIR/sanitize-inline-always.rs:5:1
+   |
+LL | #[inline(always)]
+   | ^^^^^^^^^^^^^^^^^
+