Disable old trans access via -Z orbit, #[rustc_no_mir] or --disable-orbit.

Author: eddyb

configure

@@ -733,8 +733,6 @@ if [ -n "$CFG_ENABLE_DEBUG_ASSERTIONS" ]; then putvar CFG_ENABLE_DEBUG_ASSERTION
 if [ -n "$CFG_ENABLE_DEBUGINFO" ]; then putvar CFG_ENABLE_DEBUGINFO; fi
 if [ -n "$CFG_ENABLE_DEBUG_JEMALLOC" ]; then putvar CFG_ENABLE_DEBUG_JEMALLOC; fi
 
-if [ -n "$CFG_DISABLE_ORBIT" ]; then putvar CFG_DISABLE_ORBIT; fi
-
 step_msg "looking for build programs"
 
 probe_need CFG_CURL curl

mk/main.mk

@@ -162,12 +162,6 @@ ifdef CFG_ENABLE_DEBUGINFO
   CFG_RUSTC_FLAGS += -g
 endif
 
-ifdef CFG_DISABLE_ORBIT
-  $(info cfg: HOLD HOLD HOLD (CFG_DISABLE_ORBIT))
-  RUSTFLAGS_STAGE1 += -Z orbit=off
-  RUSTFLAGS_STAGE2 += -Z orbit=off
-endif
-
 ifdef SAVE_TEMPS
   CFG_RUSTC_FLAGS += -C save-temps
 endif

src/librustc/session/config.rs

@@ -605,8 +605,6 @@ macro_rules! options {
         pub const parse_bool: Option<&'static str> = None;
         pub const parse_opt_bool: Option<&'static str> =
             Some("one of: `y`, `yes`, `on`, `n`, `no`, or `off`");
-        pub const parse_all_bool: Option<&'static str> =
-            Some("one of: `y`, `yes`, `on`, `n`, `no`, or `off`");
         pub const parse_string: Option<&'static str> = Some("a string");
         pub const parse_opt_string: Option<&'static str> = Some("a string");
         pub const parse_list: Option<&'static str> = Some("a space-separated list of strings");
@@ -656,25 +654,6 @@ macro_rules! options {
             }
         }
 
-        fn parse_all_bool(slot: &mut bool, v: Option<&str>) -> bool {
-            match v {
-                Some(s) => {
-                    match s {
-                        "n" | "no" | "off" => {
-                            *slot = false;
-                        }
-                        "y" | "yes" | "on" => {
-                            *slot = true;
-                        }
-                        _ => { return false; }
-                    }
-
-                    true
-                },
-                None => { *slot = true; true }
-            }
-        }
-
         fn parse_opt_string(slot: &mut Option<String>, v: Option<&str>) -> bool {
             match v {
                 Some(s) => { *slot = Some(s.to_string()); true },
@@ -930,8 +909,6 @@ options! {DebuggingOptions, DebuggingSetter, basic_debugging_options,
           "dump MIR state at various points in translation"),
     dump_mir_dir: Option<String> = (None, parse_opt_string, [UNTRACKED],
           "the directory the MIR is dumped into"),
-    orbit: bool = (true, parse_all_bool, [UNTRACKED],
-          "get MIR where it belongs - everywhere; most importantly, in orbit"),
 }
 
 pub fn default_lib_output() -> CrateType {
@@ -1324,15 +1301,7 @@ pub fn build_session_options_and_crate_config(matches: &getopts::Matches)
         })
     });
 
-    let mut debugging_opts = build_debugging_options(matches, error_format);
-
-    // Incremental compilation only works reliably when translation is done via
-    // MIR, so let's enable -Z orbit if necessary (see #34973).
-    if debugging_opts.incremental.is_some() && !debugging_opts.orbit {
-        early_warn(error_format, "Automatically enabling `-Z orbit` because \
-                                  `-Z incremental` was specified");
-        debugging_opts.orbit = true;
-    }
+    let debugging_opts = build_debugging_options(matches, error_format);
 
     let mir_opt_level = debugging_opts.mir_opt_level.unwrap_or(1);
 
@@ -2424,8 +2393,6 @@ mod tests {
         assert_eq!(reference.dep_tracking_hash(), opts.dep_tracking_hash());
         opts.debugging_opts.dump_mir_dir = Some(String::from("abc"));
         assert_eq!(reference.dep_tracking_hash(), opts.dep_tracking_hash());
-        opts.debugging_opts.orbit = false;
-        assert_eq!(reference.dep_tracking_hash(), opts.dep_tracking_hash());
 
         // Make sure changing a [TRACKED] option changes the hash
         opts = reference.clone();

src/librustc_trans/base.rs

@@ -1424,26 +1424,17 @@ impl<'blk, 'tcx> FunctionContext<'blk, 'tcx> {
             false
         };
 
-        let check_attrs = |attrs: &[ast::Attribute]| {
-            let default_to_mir = ccx.sess().opts.debugging_opts.orbit;
-            let invert = if default_to_mir { "rustc_no_mir" } else { "rustc_mir" };
-            (default_to_mir ^ attrs.iter().any(|item| item.check_name(invert)),
-             attrs.iter().any(|item| item.check_name("no_debug")))
-        };
-
-        let (use_mir, no_debug) = if let Some(id) = local_id {
-            check_attrs(ccx.tcx().map.attrs(id))
+        let no_debug = if let Some(id) = local_id {
+            ccx.tcx().map.attrs(id)
+               .iter().any(|item| item.check_name("no_debug"))
         } else if let Some(def_id) = def_id {
-            check_attrs(&ccx.sess().cstore.item_attrs(def_id))
+            ccx.sess().cstore.item_attrs(def_id)
+               .iter().any(|item| item.check_name("no_debug"))
         } else {
-            check_attrs(&[])
+            false
         };
 
-        let mir = if use_mir {
-            def_id.and_then(|id| ccx.get_mir(id))
-        } else {
-            None
-        };
+        let mir = def_id.and_then(|id| ccx.get_mir(id));
 
         let debug_context = if let (false, Some(definition)) = (no_debug, definition) {
             let (instance, sig, abi, _) = definition;
@@ -1846,6 +1837,8 @@ pub fn trans_closure<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
 
     if fcx.mir.is_some() {
         return mir::trans_mir(&fcx);
+    } else {
+        span_bug!(body.span, "attempted translation of `{}` w/o MIR", instance);
     }
 
     debuginfo::fill_scope_map_for_function(&fcx, decl, body, inlined_id);

src/librustc_trans/closure.rs

@@ -181,16 +181,6 @@ fn get_or_create_closure_declaration<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
     llfn
 }
 
-fn translating_closure_body_via_mir_will_fail(ccx: &CrateContext,
-                                              closure_def_id: DefId)
-                                              -> bool {
-    let default_to_mir = ccx.sess().opts.debugging_opts.orbit;
-    let invert = if default_to_mir { "rustc_no_mir" } else { "rustc_mir" };
-    let use_mir = default_to_mir ^ ccx.tcx().has_attr(closure_def_id, invert);
-
-    !use_mir
-}
-
 pub fn trans_closure_body_via_mir<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
                                             closure_def_id: DefId,
                                             closure_substs: ty::ClosureSubsts<'tcx>) {
@@ -362,15 +352,6 @@ pub fn trans_closure_method<'a, 'tcx>(ccx: &'a CrateContext<'a, 'tcx>,
                                closure_def_id,
                                substs);
         } else {
-            // If the closure is defined in an upstream crate, we can only
-            // translate it if MIR-trans is active.
-
-            if translating_closure_body_via_mir_will_fail(ccx, closure_def_id) {
-                ccx.sess().fatal("You have run into a known limitation of the \
-                                  MingW toolchain. Either compile with -Zorbit or \
-                                  with -Ccodegen-units=1 to work around it.");
-            }
-
             trans_closure_body_via_mir(ccx, closure_def_id, substs);
         }
     }

src/librustc_trans/consts.rs

@@ -1150,12 +1150,7 @@ pub fn trans_static(ccx: &CrateContext,
         let def_id = ccx.tcx().map.local_def_id(id);
         let datum = get_static(ccx, def_id);
 
-        let check_attrs = |attrs: &[ast::Attribute]| {
-            let default_to_mir = ccx.sess().opts.debugging_opts.orbit;
-            let invert = if default_to_mir { "rustc_no_mir" } else { "rustc_mir" };
-            default_to_mir ^ attrs.iter().any(|item| item.check_name(invert))
-        };
-        let use_mir = check_attrs(ccx.tcx().map.attrs(id));
+        let use_mir = true;
 
         let v = if use_mir {
             ::mir::trans_static_initializer(ccx, def_id)

src/librustc_trans/mir/mod.rs

@@ -145,7 +145,7 @@ impl<'tcx> LocalRef<'tcx> {
 ///////////////////////////////////////////////////////////////////////////
 
 pub fn trans_mir<'blk, 'tcx: 'blk>(fcx: &'blk FunctionContext<'blk, 'tcx>) {
-    let bcx = fcx.init(false, None).build();
+    let bcx = fcx.init(true, None).build();
     let mir = bcx.mir();
 
     // Analyze the temps to determine which must be lvalues

src/libsyntax/feature_gate.rs

@@ -517,11 +517,6 @@ pub const KNOWN_ATTRIBUTES: &'static [(&'static str, AttributeType, AttributeGat
                                       is just used for rustc unit tests \
                                       and will never be stable",
                                      cfg_fn!(rustc_attrs))),
-    ("rustc_no_mir", Whitelisted, Gated("rustc_attrs",
-                                        "the `#[rustc_no_mir]` attribute \
-                                         is just used to make tests pass \
-                                         and will never be stable",
-                                        cfg_fn!(rustc_attrs))),
     ("rustc_inherit_overflow_checks", Whitelisted, Gated("rustc_attrs",
                                                          "the `#[rustc_inherit_overflow_checks]` \
                                                           attribute is just used to control \

src/test/codegen/adjustments.rs

@@ -11,7 +11,6 @@
 // compile-flags: -C no-prepopulate-passes
 
 #![crate_type = "lib"]
-#![feature(rustc_attrs)]
 
 // Hack to get the correct size for the length part in slices
 // CHECK: @helper([[USIZE:i[0-9]+]])
@@ -21,13 +20,12 @@ fn helper(_: usize) {
 
 // CHECK-LABEL: @no_op_slice_adjustment
 #[no_mangle]
-#[rustc_no_mir] // FIXME #27840 MIR has different codegen.
 pub fn no_op_slice_adjustment(x: &[u8]) -> &[u8] {
     // We used to generate an extra alloca and memcpy for the block's trailing expression value, so
     // check that we copy directly to the return value slot
-// CHECK: [[SRC:%[0-9]+]] = bitcast { i8*, [[USIZE]] }* %x to
-// CHECK: [[DST:%[0-9]+]] = bitcast { i8*, [[USIZE]] }* %sret_slot to i8*
-// CHECK: call void @llvm.memcpy.{{.*}}(i8* [[DST]], i8* [[SRC]],
+// CHECK: %2 = insertvalue { i8*, [[USIZE]] } undef, i8* %0, 0
+// CHECK: %3 = insertvalue { i8*, [[USIZE]] } %2, [[USIZE]] %1, 1
+// CHECK: ret { i8*, [[USIZE]] } %3
     { x }
 }
 

src/test/codegen/coercions.rs

@@ -11,22 +11,19 @@
 // compile-flags: -C no-prepopulate-passes
 
 #![crate_type = "lib"]
-#![feature(rustc_attrs)]
 
 static X: i32 = 5;
 
 // CHECK-LABEL: @raw_ptr_to_raw_ptr_noop
 // CHECK-NOT: alloca
 #[no_mangle]
-#[rustc_no_mir] // FIXME #27840 MIR has different codegen.
 pub fn raw_ptr_to_raw_ptr_noop() -> *const i32{
     &X as *const i32
 }
 
 // CHECK-LABEL: @reference_to_raw_ptr_noop
 // CHECK-NOT: alloca
 #[no_mangle]
-#[rustc_no_mir] // FIXME #27840 MIR has different codegen.
 pub fn reference_to_raw_ptr_noop() -> *const i32 {
     &X
 }

src/test/codegen/consts.rs

@@ -11,7 +11,6 @@
 // compile-flags: -C no-prepopulate-passes
 
 #![crate_type = "lib"]
-#![feature(rustc_attrs)]
 
 // Below, these constants are defined as enum variants that by itself would
 // have a lower alignment than the enum type. Ensure that we mark them
@@ -20,11 +19,12 @@
 // CHECK: @STATIC = {{.*}}, align 4
 
 // This checks the constants from inline_enum_const
-// CHECK: @const{{[0-9]+}} = {{.*}}, align 2
+// CHECK: @ref{{[0-9]+}} = {{.*}}, align 2
 
 // This checks the constants from {low,high}_align_const, they share the same
 // constant, but the alignment differs, so the higher one should be used
-// CHECK: @const{{[0-9]+}} = {{.*}}, align 4
+// CHECK: [[LOW_HIGH:@ref[0-9]+]] = {{.*}}, align 4
+// CHECK: [[LOW_HIGH_REF:@const[0-9]+]] = {{.*}} [[LOW_HIGH]]
 
 #[derive(Copy, Clone)]
 
@@ -40,32 +40,28 @@ pub static STATIC: E<i16, i32> = E::A(0);
 
 // CHECK-LABEL: @static_enum_const
 #[no_mangle]
-#[rustc_no_mir] // FIXME #27840 MIR has different codegen.
 pub fn static_enum_const() -> E<i16, i32> {
    STATIC
 }
 
 // CHECK-LABEL: @inline_enum_const
 #[no_mangle]
-#[rustc_no_mir] // FIXME #27840 MIR has different codegen.
 pub fn inline_enum_const() -> E<i8, i16> {
-    E::A(0)
+    *&E::A(0)
 }
 
 // CHECK-LABEL: @low_align_const
 #[no_mangle]
-#[rustc_no_mir] // FIXME #27840 MIR has different codegen.
 pub fn low_align_const() -> E<i16, [i16; 3]> {
 // Check that low_align_const and high_align_const use the same constant
-// CHECK: call void @llvm.memcpy.{{.*}}(i8* %{{[0-9]+}}, i8* {{.*}} [[LOW_HIGH:@const[0-9]+]]
-    E::A(0)
+// CHECK: load {{.*}} bitcast ({ i16, i16, [4 x i8] }** [[LOW_HIGH_REF]]
+    *&E::A(0)
 }
 
 // CHECK-LABEL: @high_align_const
 #[no_mangle]
-#[rustc_no_mir] // FIXME #27840 MIR has different codegen.
 pub fn high_align_const() -> E<i16, i32> {
 // Check that low_align_const and high_align_const use the same constant
-// CHECK: call void @llvm.memcpy.{{.*}}(i8* %{{[0-9]}}, i8* {{.*}} [[LOW_HIGH]]
-    E::A(0)
+// CHECK: load {{.*}} bitcast ({ i16, i16, [4 x i8] }** [[LOW_HIGH_REF]]
+    *&E::A(0)
 }

src/test/codegen/drop.rs

@@ -11,7 +11,6 @@
 // compile-flags: -C no-prepopulate-passes
 
 #![crate_type = "lib"]
-#![feature(rustc_attrs)]
 
 struct SomeUniqueName;
 
@@ -25,19 +24,20 @@ pub fn possibly_unwinding() {
 
 // CHECK-LABEL: @droppy
 #[no_mangle]
-#[rustc_no_mir] // FIXME #27840 MIR has different codegen.
 pub fn droppy() {
 // Check that there are exactly 6 drop calls. The cleanups for the unwinding should be reused, so
 // that's one new drop call per call to possibly_unwinding(), and finally 3 drop calls for the
 // regular function exit. We used to have problems with quadratic growths of drop calls in such
 // functions.
-// CHECK: call{{.*}}drop{{.*}}SomeUniqueName
-// CHECK: call{{.*}}drop{{.*}}SomeUniqueName
-// CHECK: call{{.*}}drop{{.*}}SomeUniqueName
+// CHECK-NOT: invoke{{.*}}drop{{.*}}SomeUniqueName
 // CHECK: call{{.*}}drop{{.*}}SomeUniqueName
 // CHECK: call{{.*}}drop{{.*}}SomeUniqueName
 // CHECK: call{{.*}}drop{{.*}}SomeUniqueName
 // CHECK-NOT: call{{.*}}drop{{.*}}SomeUniqueName
+// CHECK: invoke{{.*}}drop{{.*}}SomeUniqueName
+// CHECK: invoke{{.*}}drop{{.*}}SomeUniqueName
+// CHECK: invoke{{.*}}drop{{.*}}SomeUniqueName
+// CHECK-NOT: {{(call|invoke).*}}drop{{.*}}SomeUniqueName
 // The next line checks for the } that ends the function definition
 // CHECK-LABEL: {{^[}]}}
     let _s = SomeUniqueName;

src/test/codegen/loads.rs

@@ -11,7 +11,6 @@
 // compile-flags: -C no-prepopulate-passes
 
 #![crate_type = "lib"]
-#![feature(rustc_attrs)]
 
 pub struct Bytes {
   a: u8,
@@ -22,15 +21,14 @@ pub struct Bytes {
 
 // CHECK-LABEL: @borrow
 #[no_mangle]
-#[rustc_no_mir] // FIXME #27840 MIR has different codegen.
 pub fn borrow(x: &i32) -> &i32 {
 // CHECK: load {{(i32\*, )?}}i32** %x{{.*}}, !nonnull
+    &x; // keep variable in an alloca
     x
 }
 
 // CHECK-LABEL: @_box
 #[no_mangle]
-#[rustc_no_mir] // FIXME #27840 MIR has different codegen.
 pub fn _box(x: Box<i32>) -> i32 {
 // CHECK: load {{(i32\*, )?}}i32** %x{{.*}}, !nonnull
     *x

src/test/codegen/mir_zst_stores.rs

@@ -10,7 +10,6 @@
 
 // compile-flags: -C no-prepopulate-passes
 
-#![feature(rustc_attrs)]
 #![crate_type = "lib"]
 use std::marker::PhantomData;
 
@@ -19,7 +18,6 @@ struct Zst { phantom: PhantomData<Zst> }
 
 // CHECK-LABEL: @mir
 #[no_mangle]
-#[rustc_mir]
 fn mir(){
     // CHECK-NOT: getelementptr
     // CHECK-NOT: store{{.*}}undef