Remove the no_sanitize attribute in favor of sanitize

This removes the #[no_sanitize] attribute, which was behind an unstable
feature named no_sanitize. Instead, we introduce the sanitize attribute
which is more powerful and allows to be extended in the future (instead
of just focusing on turning sanitizers off).

This also makes sanitize(kernel_address = ..) attribute work with
-Zsanitize=address

To do it the same as how clang disables address sanitizer, we now
disable ASAN on sanitize(kernel_address = "off") and KASAN on
sanitize(address = "off").

The same was added to clang in https://reviews.llvm.org/D44981.

3 files changed, 74 insertions, 30 deletions

diff --git a/src/doc/rustc-dev-guide/src/sanitizers.md b/src/doc/rustc-dev-guide/src/sanitizers.md
index 29d9056c15d..34c78d4d952 100644
--- a/src/doc/rustc-dev-guide/src/sanitizers.md
+++ b/src/doc/rustc-dev-guide/src/sanitizers.md
@@ -45,7 +45,7 @@ implementation:
    [marked][sanitizer-attribute] with appropriate LLVM attribute:
    `SanitizeAddress`, `SanitizeHWAddress`, `SanitizeMemory`, or
    `SanitizeThread`. By default all functions are instrumented, but this
-   behaviour can be changed with `#[no_sanitize(...)]`.
+   behaviour can be changed with `#[sanitize(xyz = "on|off")]`.
 
 *  The decision whether to perform instrumentation or not is possible only at a
    function granularity. In the cases were those decision differ between
diff --git a/src/doc/unstable-book/src/language-features/no-sanitize.md b/src/doc/unstable-book/src/language-features/no-sanitize.md
deleted file mode 100644
index 28c683934d4..00000000000
--- a/src/doc/unstable-book/src/language-features/no-sanitize.md
+++ /dev/null
@@ -1,29 +0,0 @@
-# `no_sanitize`
-
-The tracking issue for this feature is: [#39699]
-
-[#39699]: https://github.com/rust-lang/rust/issues/39699
-
-------------------------
-
-The `no_sanitize` attribute can be used to selectively disable sanitizer
-instrumentation in an annotated function. This might be useful to: avoid
-instrumentation overhead in a performance critical function, or avoid
-instrumenting code that contains constructs unsupported by given sanitizer.
-
-The precise effect of this annotation depends on particular sanitizer in use.
-For example, with `no_sanitize(thread)`, the thread sanitizer will no longer
-instrument non-atomic store / load operations, but it will instrument atomic
-operations to avoid reporting false positives and provide meaning full stack
-traces.
-
-## Examples
-
-``` rust
-#![feature(no_sanitize)]
-
-#[no_sanitize(address)]
-fn foo() {
-  // ...
-}
-```
diff --git a/src/doc/unstable-book/src/language-features/sanitize.md b/src/doc/unstable-book/src/language-features/sanitize.md
new file mode 100644
index 00000000000..fcd099cb36e
--- /dev/null
+++ b/src/doc/unstable-book/src/language-features/sanitize.md
@@ -0,0 +1,73 @@
+# `sanitize`
+
+The tracking issue for this feature is: [#39699]
+
+[#39699]: https://github.com/rust-lang/rust/issues/39699
+
+------------------------
+
+The `sanitize` attribute can be used to selectively disable or enable sanitizer
+instrumentation in an annotated function. This might be useful to: avoid
+instrumentation overhead in a performance critical function, or avoid
+instrumenting code that contains constructs unsupported by given sanitizer.
+
+The precise effect of this annotation depends on particular sanitizer in use.
+For example, with `sanitize(thread = "off")`, the thread sanitizer will no
+longer instrument non-atomic store / load operations, but it will instrument
+atomic operations to avoid reporting false positives and provide meaning full
+stack traces.
+
+This attribute was previously named `no_sanitize`.
+
+## Examples
+
+``` rust
+#![feature(sanitize)]
+
+#[sanitize(address = "off")]
+fn foo() {
+  // ...
+}
+```
+
+It is also possible to disable sanitizers for entire modules and enable them
+for single items or functions.
+
+```rust
+#![feature(sanitize)]
+
+#[sanitize(address = "off")]
+mod foo {
+  fn unsanitized() {
+    // ...
+  }
+
+  #[sanitize(address = "on")]
+  fn sanitized() {
+    // ...
+  }
+}
+```
+
+It's also applicable to impl blocks.
+
+```rust
+#![feature(sanitize)]
+
+trait MyTrait {
+  fn foo(&self);
+  fn bar(&self);
+}
+
+#[sanitize(address = "off")]
+impl MyTrait for () {
+  fn foo(&self) {
+    // ...
+  }
+
+  #[sanitize(address = "on")]
+  fn bar(&self) {
+    // ...
+  }
+}
+```