handle cfg bootstrap on compiler and compiler tools

Signed-off-by: onur-ozkan <work@onurozkan.dev>

Author: onur-ozkan

compiler/rustc_lint/src/lib.rs

@@ -21,6 +21,7 @@
 
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(extract_if))]
 #![cfg_attr(doc, recursion_limit = "256")] // FIXME(nnethercote): will be removed by #124141
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]

compiler/rustc_metadata/src/lib.rs

@@ -1,5 +1,6 @@
 // tidy-alphabetical-start
 #![allow(internal_features)]
+#![cfg_attr(bootstrap, feature(extract_if))]
 #![cfg_attr(doc, recursion_limit = "256")] // FIXME(nnethercote): will be removed by #124141
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]

compiler/rustc_middle/src/lib.rs

@@ -29,6 +29,7 @@
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::potential_query_instability)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![cfg_attr(bootstrap, feature(extract_if))]
 #![cfg_attr(doc, recursion_limit = "256")] // FIXME(nnethercote): will be removed by #124141
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]

compiler/rustc_resolve/src/lib.rs

@@ -11,6 +11,7 @@
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::potential_query_instability)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![cfg_attr(bootstrap, feature(extract_if))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(assert_matches)]

compiler/rustc_serialize/src/lib.rs

@@ -3,6 +3,7 @@
 // tidy-alphabetical-start
 #![allow(internal_features)]
 #![allow(rustc::internal)]
+#![cfg_attr(bootstrap, feature(ptr_sub_ptr))]
 #![cfg_attr(test, feature(test))]
 #![doc(
     html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/",

compiler/rustc_serialize/src/opaque.rs

@@ -280,13 +280,27 @@ impl<'a> MemDecoder<'a> {
     #[inline]
     pub fn len(&self) -> usize {
         // SAFETY: This recovers the length of the original slice, only using members we never modify.
-        unsafe { self.end.offset_from_unsigned(self.start) }
+        #[cfg(bootstrap)]
+        unsafe {
+            return self.end.sub_ptr(self.start);
+        }
+        #[cfg(not(bootstrap))]
+        unsafe {
+            self.end.offset_from_unsigned(self.start)
+        }
     }
 
     #[inline]
     pub fn remaining(&self) -> usize {
         // SAFETY: This type guarantees current <= end.
-        unsafe { self.end.offset_from_unsigned(self.current) }
+        #[cfg(bootstrap)]
+        unsafe {
+            return self.end.sub_ptr(self.current);
+        }
+        #[cfg(not(bootstrap))]
+        unsafe {
+            self.end.offset_from_unsigned(self.current)
+        }
     }
 
     #[cold]
@@ -400,7 +414,14 @@ impl<'a> Decoder for MemDecoder<'a> {
     #[inline]
     fn position(&self) -> usize {
         // SAFETY: This type guarantees start <= current
-        unsafe { self.current.offset_from_unsigned(self.start) }
+        #[cfg(bootstrap)]
+        unsafe {
+            return self.current.sub_ptr(self.start);
+        }
+        #[cfg(not(bootstrap))]
+        unsafe {
+            self.current.offset_from_unsigned(self.start)
+        }
     }
 }
 

compiler/rustc_trait_selection/src/lib.rs

@@ -14,6 +14,7 @@
 #![allow(internal_features)]
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![cfg_attr(bootstrap, feature(extract_if))]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(assert_matches)]

src/librustdoc/lib.rs

@@ -22,6 +22,7 @@
 #![allow(clippy::collapsible_if, clippy::collapsible_else_if)]
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
+#![cfg_attr(bootstrap, feature(os_str_display))]
 
 extern crate thin_vec;
 

src/tools/miri/src/lib.rs

@@ -1,3 +1,5 @@
+#![cfg_attr(bootstrap, feature(extract_if))]
+#![cfg_attr(bootstrap, feature(unsigned_is_multiple_of))]
 #![feature(rustc_private)]
 #![feature(cfg_match)]
 #![feature(cell_update)]