Auto merge of #76931 - oli-obk:const_prop_inline_lint_madness, r=wesl…

…eywiser

Properly handle lint spans after MIR inlining

The first commit shows what happens when we apply mir inlining and then cause lints on the inlined MIR.
The second commit fixes that.

r? `@wesleywiser`

compiler/rustc_errors/src/emitter.rs

@@ -299,7 +299,7 @@ pub trait Emitter {
 
                     // Skip past non-macro entries, just in case there
                     // are some which do actually involve macros.
-                    ExpnKind::Desugaring(..) | ExpnKind::AstPass(..) => None,
+                    ExpnKind::Inlined | ExpnKind::Desugaring(..) | ExpnKind::AstPass(..) => None,
 
                     ExpnKind::Macro(macro_kind, _) => Some(macro_kind),
                 }
@@ -359,7 +359,10 @@ pub trait Emitter {
                     continue;
                 }
 
-                if always_backtrace {
+                if matches!(trace.kind, ExpnKind::Inlined) {
+                    new_labels
+                        .push((trace.call_site, "in the inlined copy of this code".to_string()));
+                } else if always_backtrace {
                     new_labels.push((
                         trace.def_site,
                         format!(

compiler/rustc_middle/src/lint.rs

@@ -371,7 +371,9 @@ pub fn struct_lint_level<'s, 'd>(
 pub fn in_external_macro(sess: &Session, span: Span) -> bool {
     let expn_data = span.ctxt().outer_expn_data();
     match expn_data.kind {
-        ExpnKind::Root | ExpnKind::Desugaring(DesugaringKind::ForLoop(_)) => false,
+        ExpnKind::Inlined | ExpnKind::Root | ExpnKind::Desugaring(DesugaringKind::ForLoop(_)) => {
+            false
+        }
         ExpnKind::AstPass(_) | ExpnKind::Desugaring(_) => true, // well, it's "external"
         ExpnKind::Macro(MacroKind::Bang, _) => {
             // Dummy span for the `def_site` means it's an external macro.

compiler/rustc_mir/src/transform/inline.rs

@@ -8,6 +8,7 @@ use rustc_middle::mir::visit::*;
 use rustc_middle::mir::*;
 use rustc_middle::ty::subst::Subst;
 use rustc_middle::ty::{self, ConstKind, Instance, InstanceDef, ParamEnv, Ty, TyCtxt};
+use rustc_span::{hygiene::ExpnKind, ExpnData, Span};
 use rustc_target::spec::abi::Abi;
 
 use super::simplify::{remove_dead_blocks, CfgSimplifier};
@@ -471,6 +472,8 @@ impl Inliner<'tcx> {
                     cleanup_block: cleanup,
                     in_cleanup_block: false,
                     tcx: self.tcx,
+                    callsite_span: callsite.source_info.span,
+                    body_span: callee_body.span,
                 };
 
                 // Map all `Local`s, `SourceScope`s and `BasicBlock`s to new ones
@@ -682,6 +685,8 @@ struct Integrator<'a, 'tcx> {
     cleanup_block: Option<BasicBlock>,
     in_cleanup_block: bool,
     tcx: TyCtxt<'tcx>,
+    callsite_span: Span,
+    body_span: Span,
 }
 
 impl<'a, 'tcx> Integrator<'a, 'tcx> {
@@ -726,6 +731,14 @@ impl<'a, 'tcx> MutVisitor<'tcx> for Integrator<'a, 'tcx> {
         *scope = self.map_scope(*scope);
     }
 
+    fn visit_span(&mut self, span: &mut Span) {
+        // Make sure that all spans track the fact that they were inlined.
+        *span = self.callsite_span.fresh_expansion(ExpnData {
+            def_site: self.body_span,
+            ..ExpnData::default(ExpnKind::Inlined, *span, self.tcx.sess.edition(), None)
+        });
+    }
+
     fn visit_place(&mut self, place: &mut Place<'tcx>, context: PlaceContext, location: Location) {
         // If this is the `RETURN_PLACE`, we need to rebase any projections onto it.
         let dest_proj_len = self.destination.projection.len();

compiler/rustc_save_analysis/src/lib.rs

@@ -799,7 +799,9 @@ impl<'tcx> SaveContext<'tcx> {
 
             // These are not macros.
             // FIXME(eddyb) maybe there is a way to handle them usefully?
-            ExpnKind::Root | ExpnKind::AstPass(_) | ExpnKind::Desugaring(_) => return None,
+            ExpnKind::Inlined | ExpnKind::Root | ExpnKind::AstPass(_) | ExpnKind::Desugaring(_) => {
+                return None;
+            }
         };
 
         let callee_span = self.span_from_span(callee.def_site);

compiler/rustc_span/src/hygiene.rs

@@ -766,6 +766,8 @@ pub enum ExpnKind {
     AstPass(AstPass),
     /// Desugaring done by the compiler during HIR lowering.
     Desugaring(DesugaringKind),
+    /// MIR inlining
+    Inlined,
 }
 
 impl ExpnKind {
@@ -779,6 +781,7 @@ impl ExpnKind {
             },
             ExpnKind::AstPass(kind) => kind.descr().to_string(),
             ExpnKind::Desugaring(kind) => format!("desugaring of {}", kind.descr()),
+            ExpnKind::Inlined => "inlined source".to_string(),
         }
     }
 }

src/test/mir-opt/dest-prop/cycle.main.DestinationPropagation.diff

@@ -19,7 +19,7 @@
 -                 debug z => _3;           // in scope 3 at $DIR/cycle.rs:11:9: 11:10
 +                 debug z => _4;           // in scope 3 at $DIR/cycle.rs:11:9: 11:10
                   scope 4 (inlined std::mem::drop::<i32>) { // at $DIR/cycle.rs:14:5: 14:12
-                      debug _x => _6;      // in scope 4 at $SRC_DIR/core/src/mem/mod.rs:LL:COL
+                      debug _x => _6;      // in scope 4 at $DIR/cycle.rs:14:5: 14:12
                   }
               }
           }
@@ -56,7 +56,7 @@
           StorageLive(_6);                 // scope 3 at $DIR/cycle.rs:14:10: 14:11
 -         _6 = _1;                         // scope 3 at $DIR/cycle.rs:14:10: 14:11
 +         _6 = _4;                         // scope 3 at $DIR/cycle.rs:14:10: 14:11
-          _5 = const ();                   // scope 4 at $SRC_DIR/core/src/mem/mod.rs:LL:COL
+          _5 = const ();                   // scope 4 at $DIR/cycle.rs:14:5: 14:12
           StorageDead(_6);                 // scope 3 at $DIR/cycle.rs:14:11: 14:12
           StorageDead(_5);                 // scope 3 at $DIR/cycle.rs:14:12: 14:13
           _0 = const ();                   // scope 0 at $DIR/cycle.rs:8:11: 15:2

src/test/mir-opt/dest-prop/union.main.DestinationPropagation.diff

@@ -12,7 +12,7 @@
           scope 2 {
           }
           scope 3 (inlined std::mem::drop::<u32>) { // at $DIR/union.rs:15:5: 15:27
-              debug _x => _4;              // in scope 3 at $SRC_DIR/core/src/mem/mod.rs:LL:COL
+              debug _x => _4;              // in scope 3 at $DIR/union.rs:15:5: 15:27
           }
       }
 
@@ -31,7 +31,7 @@
           StorageLive(_3);                 // scope 1 at $DIR/union.rs:15:5: 15:27
           StorageLive(_4);                 // scope 1 at $DIR/union.rs:15:10: 15:26
           _4 = (_1.0: u32);                // scope 2 at $DIR/union.rs:15:19: 15:24
-          _3 = const ();                   // scope 3 at $SRC_DIR/core/src/mem/mod.rs:LL:COL
+          _3 = const ();                   // scope 3 at $DIR/union.rs:15:5: 15:27
           StorageDead(_4);                 // scope 1 at $DIR/union.rs:15:26: 15:27
           StorageDead(_3);                 // scope 1 at $DIR/union.rs:15:27: 15:28
           _0 = const ();                   // scope 0 at $DIR/union.rs:8:11: 16:2

src/test/mir-opt/generator_drop_cleanup.main-{closure#0}.generator_drop.0.mir

@@ -27,8 +27,8 @@ fn main::{closure#0}(_1: *mut [generator@$DIR/generator-drop-cleanup.rs:10:15: 1
         debug _s => (((*_1) as variant#3).0: std::string::String); // in scope 1 at $DIR/generator-drop-cleanup.rs:11:13: 11:15
     }
     scope 2 (inlined String::new) {      // at $DIR/generator-drop-cleanup.rs:11:18: 11:31
-        let mut _6: std::vec::Vec<u8>;   // in scope 2 at $SRC_DIR/alloc/src/string.rs:LL:COL
-        scope 3 (inlined Vec::<u8>::new) { // at $SRC_DIR/alloc/src/string.rs:LL:COL
+        let mut _6: std::vec::Vec<u8>;   // in scope 2 at $DIR/generator-drop-cleanup.rs:11:18: 11:31
+        scope 3 (inlined Vec::<u8>::new) { // at $DIR/generator-drop-cleanup.rs:11:18: 11:31
         }
     }
 

src/test/mir-opt/inline/inline_any_operand.bar.Inline.after.mir

@@ -9,10 +9,10 @@ fn bar() -> bool {
     scope 1 {
         debug f => _1;                   // in scope 1 at $DIR/inline-any-operand.rs:11:9: 11:10
         scope 2 (inlined foo) {          // at $DIR/inline-any-operand.rs:12:5: 12:13
-            debug x => _3;               // in scope 2 at $DIR/inline-any-operand.rs:16:8: 16:9
-            debug y => _4;               // in scope 2 at $DIR/inline-any-operand.rs:16:16: 16:17
-            let mut _5: i32;             // in scope 2 at $DIR/inline-any-operand.rs:17:5: 17:6
-            let mut _6: i32;             // in scope 2 at $DIR/inline-any-operand.rs:17:10: 17:11
+            debug x => _3;               // in scope 2 at $DIR/inline-any-operand.rs:12:5: 12:13
+            debug y => _4;               // in scope 2 at $DIR/inline-any-operand.rs:12:5: 12:13
+            let mut _5: i32;             // in scope 2 at $DIR/inline-any-operand.rs:12:5: 12:13
+            let mut _6: i32;             // in scope 2 at $DIR/inline-any-operand.rs:12:5: 12:13
         }
     }
 
@@ -28,13 +28,13 @@ fn bar() -> bool {
         _3 = const 1_i32;                // scope 1 at $DIR/inline-any-operand.rs:12:5: 12:13
         StorageLive(_4);                 // scope 1 at $DIR/inline-any-operand.rs:12:5: 12:13
         _4 = const -1_i32;               // scope 1 at $DIR/inline-any-operand.rs:12:5: 12:13
-        StorageLive(_5);                 // scope 2 at $DIR/inline-any-operand.rs:17:5: 17:6
-        _5 = _3;                         // scope 2 at $DIR/inline-any-operand.rs:17:5: 17:6
-        StorageLive(_6);                 // scope 2 at $DIR/inline-any-operand.rs:17:10: 17:11
-        _6 = _4;                         // scope 2 at $DIR/inline-any-operand.rs:17:10: 17:11
-        _0 = Eq(move _5, move _6);       // scope 2 at $DIR/inline-any-operand.rs:17:5: 17:11
-        StorageDead(_6);                 // scope 2 at $DIR/inline-any-operand.rs:17:10: 17:11
-        StorageDead(_5);                 // scope 2 at $DIR/inline-any-operand.rs:17:10: 17:11
+        StorageLive(_5);                 // scope 2 at $DIR/inline-any-operand.rs:12:5: 12:13
+        _5 = _3;                         // scope 2 at $DIR/inline-any-operand.rs:12:5: 12:13
+        StorageLive(_6);                 // scope 2 at $DIR/inline-any-operand.rs:12:5: 12:13
+        _6 = _4;                         // scope 2 at $DIR/inline-any-operand.rs:12:5: 12:13
+        _0 = Eq(move _5, move _6);       // scope 2 at $DIR/inline-any-operand.rs:12:5: 12:13
+        StorageDead(_6);                 // scope 2 at $DIR/inline-any-operand.rs:12:5: 12:13
+        StorageDead(_5);                 // scope 2 at $DIR/inline-any-operand.rs:12:5: 12:13
         StorageDead(_4);                 // scope 1 at $DIR/inline-any-operand.rs:12:5: 12:13
         StorageDead(_3);                 // scope 1 at $DIR/inline-any-operand.rs:12:5: 12:13
         StorageDead(_2);                 // scope 1 at $DIR/inline-any-operand.rs:12:12: 12:13

src/test/mir-opt/inline/inline_closure.foo.Inline.after.mir

@@ -14,8 +14,8 @@ fn foo(_1: T, _2: i32) -> i32 {
     scope 1 {
         debug x => _3;                   // in scope 1 at $DIR/inline-closure.rs:11:9: 11:10
         scope 2 (inlined foo::<T>::{closure#0}) { // at $DIR/inline-closure.rs:12:5: 12:12
-            debug _t => _8;              // in scope 2 at $DIR/inline-closure.rs:11:14: 11:16
-            debug _q => _9;              // in scope 2 at $DIR/inline-closure.rs:11:18: 11:20
+            debug _t => _8;              // in scope 2 at $DIR/inline-closure.rs:12:5: 12:12
+            debug _q => _9;              // in scope 2 at $DIR/inline-closure.rs:12:5: 12:12
         }
     }
 
@@ -34,7 +34,7 @@ fn foo(_1: T, _2: i32) -> i32 {
         _8 = move (_5.0: i32);           // scope 1 at $DIR/inline-closure.rs:12:5: 12:12
         StorageLive(_9);                 // scope 1 at $DIR/inline-closure.rs:12:5: 12:12
         _9 = move (_5.1: i32);           // scope 1 at $DIR/inline-closure.rs:12:5: 12:12
-        _0 = _8;                         // scope 2 at $DIR/inline-closure.rs:11:22: 11:24
+        _0 = _8;                         // scope 2 at $DIR/inline-closure.rs:12:5: 12:12
         StorageDead(_9);                 // scope 1 at $DIR/inline-closure.rs:12:5: 12:12
         StorageDead(_8);                 // scope 1 at $DIR/inline-closure.rs:12:5: 12:12
         StorageDead(_7);                 // scope 1 at $DIR/inline-closure.rs:12:11: 12:12

src/test/mir-opt/inline/inline_closure_borrows_arg.foo.Inline.after.mir

@@ -14,11 +14,11 @@ fn foo(_1: T, _2: &i32) -> i32 {
     scope 1 {
         debug x => _3;                   // in scope 1 at $DIR/inline-closure-borrows-arg.rs:12:9: 12:10
         scope 2 (inlined foo::<T>::{closure#0}) { // at $DIR/inline-closure-borrows-arg.rs:16:5: 16:12
-            debug r => _8;               // in scope 2 at $DIR/inline-closure-borrows-arg.rs:12:14: 12:15
-            debug _s => _9;              // in scope 2 at $DIR/inline-closure-borrows-arg.rs:12:23: 12:25
-            let _10: &i32;               // in scope 2 at $DIR/inline-closure-borrows-arg.rs:13:13: 13:21
+            debug r => _8;               // in scope 2 at $DIR/inline-closure-borrows-arg.rs:16:5: 16:12
+            debug _s => _9;              // in scope 2 at $DIR/inline-closure-borrows-arg.rs:16:5: 16:12
+            let _10: &i32;               // in scope 2 at $DIR/inline-closure-borrows-arg.rs:16:5: 16:12
             scope 3 {
-                debug variable => _10;   // in scope 3 at $DIR/inline-closure-borrows-arg.rs:13:13: 13:21
+                debug variable => _10;   // in scope 3 at $DIR/inline-closure-borrows-arg.rs:16:5: 16:12
             }
         }
     }
@@ -38,10 +38,10 @@ fn foo(_1: T, _2: &i32) -> i32 {
         _8 = move (_5.0: &i32);          // scope 1 at $DIR/inline-closure-borrows-arg.rs:16:5: 16:12
         StorageLive(_9);                 // scope 1 at $DIR/inline-closure-borrows-arg.rs:16:5: 16:12
         _9 = move (_5.1: &i32);          // scope 1 at $DIR/inline-closure-borrows-arg.rs:16:5: 16:12
-        StorageLive(_10);                // scope 2 at $DIR/inline-closure-borrows-arg.rs:13:13: 13:21
-        _10 = _8;                        // scope 2 at $DIR/inline-closure-borrows-arg.rs:13:24: 13:27
-        _0 = (*_8);                      // scope 3 at $DIR/inline-closure-borrows-arg.rs:14:9: 14:18
-        StorageDead(_10);                // scope 2 at $DIR/inline-closure-borrows-arg.rs:15:5: 15:6
+        StorageLive(_10);                // scope 2 at $DIR/inline-closure-borrows-arg.rs:16:5: 16:12
+        _10 = _8;                        // scope 2 at $DIR/inline-closure-borrows-arg.rs:16:5: 16:12
+        _0 = (*_8);                      // scope 3 at $DIR/inline-closure-borrows-arg.rs:16:5: 16:12
+        StorageDead(_10);                // scope 2 at $DIR/inline-closure-borrows-arg.rs:16:5: 16:12
         StorageDead(_9);                 // scope 1 at $DIR/inline-closure-borrows-arg.rs:16:5: 16:12
         StorageDead(_8);                 // scope 1 at $DIR/inline-closure-borrows-arg.rs:16:5: 16:12
         StorageDead(_7);                 // scope 1 at $DIR/inline-closure-borrows-arg.rs:16:11: 16:12

src/test/mir-opt/inline/inline_closure_captures.foo.Inline.after.mir

@@ -14,10 +14,10 @@ fn foo(_1: T, _2: i32) -> (i32, T) {
     scope 1 {
         debug x => _3;                   // in scope 1 at $DIR/inline-closure-captures.rs:11:9: 11:10
         scope 2 (inlined foo::<T>::{closure#0}) { // at $DIR/inline-closure-captures.rs:12:5: 12:9
-            debug _q => _9;              // in scope 2 at $DIR/inline-closure-captures.rs:11:14: 11:16
-            debug q => (*((*_6).0: &i32)); // in scope 2 at $DIR/inline-closure-captures.rs:10:23: 10:24
-            debug t => (*((*_6).1: &T)); // in scope 2 at $DIR/inline-closure-captures.rs:10:17: 10:18
-            let mut _10: T;              // in scope 2 at $DIR/inline-closure-captures.rs:11:22: 11:23
+            debug _q => _9;              // in scope 2 at $DIR/inline-closure-captures.rs:12:5: 12:9
+            debug q => (*((*_6).0: &i32)); // in scope 2 at $DIR/inline-closure-captures.rs:12:5: 12:9
+            debug t => (*((*_6).1: &T)); // in scope 2 at $DIR/inline-closure-captures.rs:12:5: 12:9
+            let mut _10: T;              // in scope 2 at $DIR/inline-closure-captures.rs:12:5: 12:9
         }
     }
 
@@ -39,11 +39,11 @@ fn foo(_1: T, _2: i32) -> (i32, T) {
         (_7.0: i32) = move _8;           // scope 1 at $DIR/inline-closure-captures.rs:12:5: 12:9
         StorageLive(_9);                 // scope 1 at $DIR/inline-closure-captures.rs:12:5: 12:9
         _9 = move (_7.0: i32);           // scope 1 at $DIR/inline-closure-captures.rs:12:5: 12:9
-        (_0.0: i32) = (*((*_6).0: &i32)); // scope 2 at $DIR/inline-closure-captures.rs:11:19: 11:20
-        StorageLive(_10);                // scope 2 at $DIR/inline-closure-captures.rs:11:22: 11:23
-        _10 = (*((*_6).1: &T));          // scope 2 at $DIR/inline-closure-captures.rs:11:22: 11:23
-        (_0.1: T) = move _10;            // scope 2 at $DIR/inline-closure-captures.rs:11:18: 11:24
-        StorageDead(_10);                // scope 2 at $DIR/inline-closure-captures.rs:11:23: 11:24
+        (_0.0: i32) = (*((*_6).0: &i32)); // scope 2 at $DIR/inline-closure-captures.rs:12:5: 12:9
+        StorageLive(_10);                // scope 2 at $DIR/inline-closure-captures.rs:12:5: 12:9
+        _10 = (*((*_6).1: &T));          // scope 2 at $DIR/inline-closure-captures.rs:12:5: 12:9
+        (_0.1: T) = move _10;            // scope 2 at $DIR/inline-closure-captures.rs:12:5: 12:9
+        StorageDead(_10);                // scope 2 at $DIR/inline-closure-captures.rs:12:5: 12:9
         StorageDead(_9);                 // scope 1 at $DIR/inline-closure-captures.rs:12:5: 12:9
         StorageDead(_8);                 // scope 1 at $DIR/inline-closure-captures.rs:12:8: 12:9
         StorageDead(_7);                 // scope 1 at $DIR/inline-closure-captures.rs:12:8: 12:9

src/test/mir-opt/inline/inline_compatibility.inlined_no_sanitize.Inline.diff

@@ -16,7 +16,7 @@
 -     }
 - 
 -     bb1: {
-+         _1 = const ();                   // scope 1 at $DIR/inline-compatibility.rs:39:29: 39:31
++         _1 = const ();                   // scope 1 at $DIR/inline-compatibility.rs:25:5: 25:18
           StorageDead(_1);                 // scope 0 at $DIR/inline-compatibility.rs:25:18: 25:19
           _0 = const ();                   // scope 0 at $DIR/inline-compatibility.rs:24:37: 26:2
           return;                          // scope 0 at $DIR/inline-compatibility.rs:26:2: 26:2

src/test/mir-opt/inline/inline_compatibility.inlined_target_feature.Inline.diff

@@ -16,7 +16,7 @@
 -     }
 - 
 -     bb1: {
-+         _1 = const ();                   // scope 1 at $DIR/inline-compatibility.rs:35:32: 35:34
++         _1 = const ();                   // scope 1 at $DIR/inline-compatibility.rs:14:5: 14:21
           StorageDead(_1);                 // scope 0 at $DIR/inline-compatibility.rs:14:21: 14:22
           _0 = const ();                   // scope 0 at $DIR/inline-compatibility.rs:13:40: 15:2
           return;                          // scope 0 at $DIR/inline-compatibility.rs:15:2: 15:2