Use larger span for adjustment THIR expressions

compiler/rustc_mir_build/src/thir/cx/expr.rs

@@ -39,10 +39,17 @@ impl<'tcx> Cx<'tcx> {
 
         let mut expr = self.make_mirror_unadjusted(hir_expr);
 
+        let adjustment_span = match self.adjustment_span {
+            Some((hir_id, span)) if hir_id == hir_expr.hir_id => Some(span),
+            _ => None,
+        };
+
         // Now apply adjustments, if any.
         for adjustment in self.typeck_results.expr_adjustments(hir_expr) {
             debug!("make_mirror: expr={:?} applying adjustment={:?}", expr, adjustment);
-            expr = self.apply_adjustment(hir_expr, expr, adjustment);
+            let span = expr.span;
+            expr =
+                self.apply_adjustment(hir_expr, expr, adjustment, adjustment_span.unwrap_or(span));
         }
 
         // Next, wrap this up in the expr's scope.
@@ -82,8 +89,9 @@ impl<'tcx> Cx<'tcx> {
         hir_expr: &'tcx hir::Expr<'tcx>,
         mut expr: Expr<'tcx>,
         adjustment: &Adjustment<'tcx>,
+        mut span: Span,
     ) -> Expr<'tcx> {
-        let Expr { temp_lifetime, mut span, .. } = expr;
+        let Expr { temp_lifetime, .. } = expr;
 
         // Adjust the span from the block, to the last expression of the
         // block. This is a better span when returning a mutable reference
@@ -150,14 +158,21 @@ impl<'tcx> Cx<'tcx> {
 
     fn make_mirror_unadjusted(&mut self, expr: &'tcx hir::Expr<'tcx>) -> Expr<'tcx> {
         let expr_ty = self.typeck_results().expr_ty(expr);
+        let expr_span = expr.span;
         let temp_lifetime = self.region_scope_tree.temporary_scope(expr.hir_id.local_id);
 
         let kind = match expr.kind {
             // Here comes the interesting stuff:
             hir::ExprKind::MethodCall(_, method_span, ref args, fn_span) => {
                 // Rewrite a.b(c) into UFCS form like Trait::b(a, c)
                 let expr = self.method_callee(expr, method_span, None);
+                // When we apply adjustments to the receiver, use the span of
+                // the overall method call for better diagnostics. args[0]
+                // is guaranteed to exist, since a method call always has a receiver.
+                let old_adjustment_span = self.adjustment_span.replace((args[0].hir_id, expr_span));
+                tracing::info!("Using method span: {:?}", expr.span);
                 let args = self.mirror_exprs(args);
+                self.adjustment_span = old_adjustment_span;
                 ExprKind::Call {
                     ty: expr.ty,
                     fun: self.thir.exprs.push(expr),

compiler/rustc_mir_build/src/thir/cx/mod.rs

@@ -9,6 +9,7 @@ use rustc_ast as ast;
 use rustc_data_structures::steal::Steal;
 use rustc_hir as hir;
 use rustc_hir::def_id::{DefId, LocalDefId};
+use rustc_hir::HirId;
 use rustc_hir::Node;
 use rustc_middle::middle::region;
 use rustc_middle::mir::interpret::{LitToConstError, LitToConstInput};
@@ -46,6 +47,14 @@ struct Cx<'tcx> {
     crate region_scope_tree: &'tcx region::ScopeTree,
     crate typeck_results: &'tcx ty::TypeckResults<'tcx>,
 
+    /// When applying adjustments to the expression
+    /// with the given `HirId`, use the given `Span`,
+    /// instead of the usual span. This is used to
+    /// assign the span of an overall method call
+    /// (e.g. `my_val.foo()`) to the adjustment expressions
+    /// for the receiver.
+    adjustment_span: Option<(HirId, Span)>,
+
     /// The `DefId` of the owner of this body.
     body_owner: DefId,
 }
@@ -60,6 +69,7 @@ impl<'tcx> Cx<'tcx> {
             region_scope_tree: tcx.region_scope_tree(def.did),
             typeck_results,
             body_owner: def.did.to_def_id(),
+            adjustment_span: None,
         }
     }
 

src/test/mir-opt/const_promotion_extern_static.BAR-promoted[0].SimplifyCfg-elaborate-drops.after.mir

@@ -1,7 +1,7 @@
 // MIR for `BAR::promoted[0]` after SimplifyCfg-elaborate-drops
 
 promoted[0] in BAR: &[&i32; 1] = {
-    let mut _0: &[&i32; 1];              // return place in scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:35
+    let mut _0: &[&i32; 1];              // return place in scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:44
     let mut _1: [&i32; 1];               // in scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:35
     let mut _2: &i32;                    // in scope 0 at $DIR/const-promotion-extern-static.rs:9:32: 9:34
     let mut _3: &i32;                    // in scope 0 at $DIR/const-promotion-extern-static.rs:9:33: 9:34
@@ -16,8 +16,8 @@ promoted[0] in BAR: &[&i32; 1] = {
                                          // + literal: Const { ty: &i32, val: Value(Scalar(alloc1)) }
         _2 = &(*_3);                     // scope 0 at $DIR/const-promotion-extern-static.rs:9:32: 9:34
         _1 = [move _2];                  // scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:35
-        _0 = &_1;                        // scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:35
-        return;                          // scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:35
+        _0 = &_1;                        // scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:44
+        return;                          // scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:44
     }
 }
 

src/test/mir-opt/const_promotion_extern_static.BAR.PromoteTemps.diff

@@ -3,21 +3,21 @@
 
   static mut BAR: *const &i32 = {
       let mut _0: *const &i32;             // return place in scope 0 at $DIR/const-promotion-extern-static.rs:9:17: 9:28
-      let mut _1: &[&i32];                 // in scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:35
-      let mut _2: &[&i32; 1];              // in scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:35
+      let mut _1: &[&i32];                 // in scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:44
+      let mut _2: &[&i32; 1];              // in scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:44
       let _3: [&i32; 1];                   // in scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:35
       let mut _4: &i32;                    // in scope 0 at $DIR/const-promotion-extern-static.rs:9:32: 9:34
       let _5: &i32;                        // in scope 0 at $DIR/const-promotion-extern-static.rs:9:33: 9:34
-+     let mut _6: &[&i32; 1];              // in scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:35
++     let mut _6: &[&i32; 1];              // in scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:44
 
       bb0: {
-          StorageLive(_1);                 // scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:35
-          StorageLive(_2);                 // scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:35
+          StorageLive(_1);                 // scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:44
+          StorageLive(_2);                 // scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:44
 -         StorageLive(_3);                 // scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:35
 -         StorageLive(_4);                 // scope 0 at $DIR/const-promotion-extern-static.rs:9:32: 9:34
 -         StorageLive(_5);                 // scope 0 at $DIR/const-promotion-extern-static.rs:9:33: 9:34
 -         _5 = const {alloc1: &i32};       // scope 0 at $DIR/const-promotion-extern-static.rs:9:33: 9:34
-+         _6 = const BAR::promoted[0];     // scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:35
++         _6 = const BAR::promoted[0];     // scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:44
                                            // ty::Const
 -                                          // + ty: &i32
 -                                          // + val: Value(Scalar(alloc1))
@@ -28,11 +28,11 @@
 -                                          // + literal: Const { ty: &i32, val: Value(Scalar(alloc1)) }
 -         _4 = &(*_5);                     // scope 0 at $DIR/const-promotion-extern-static.rs:9:32: 9:34
 -         _3 = [move _4];                  // scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:35
--         _2 = &_3;                        // scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:35
-+                                          // + span: $DIR/const-promotion-extern-static.rs:9:31: 9:35
+-         _2 = &_3;                        // scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:44
++                                          // + span: $DIR/const-promotion-extern-static.rs:9:31: 9:44
 +                                          // + literal: Const { ty: &[&i32; 1], val: Unevaluated(Unevaluated { def: WithOptConstParam { did: DefId(0:6 ~ const_promotion_extern_static[55e6]::BAR), const_param_did: None }, substs_: Some([]), promoted: Some(promoted[0]) }) }
-+         _2 = &(*_6);                     // scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:35
-          _1 = move _2 as &[&i32] (Pointer(Unsize)); // scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:35
++         _2 = &(*_6);                     // scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:44
+          _1 = move _2 as &[&i32] (Pointer(Unsize)); // scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:44
 -         StorageDead(_4);                 // scope 0 at $DIR/const-promotion-extern-static.rs:9:34: 9:35
           StorageDead(_2);                 // scope 0 at $DIR/const-promotion-extern-static.rs:9:34: 9:35
           _0 = core::slice::<impl [&i32]>::as_ptr(move _1) -> [return: bb1, unwind: bb2]; // scope 0 at $DIR/const-promotion-extern-static.rs:9:31: 9:44

src/test/mir-opt/const_promotion_extern_static.FOO-promoted[0].SimplifyCfg-elaborate-drops.after.mir

@@ -1,7 +1,7 @@
 // MIR for `FOO::promoted[0]` after SimplifyCfg-elaborate-drops
 
 promoted[0] in FOO: &[&i32; 1] = {
-    let mut _0: &[&i32; 1];              // return place in scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:46
+    let mut _0: &[&i32; 1];              // return place in scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:55
     let mut _1: [&i32; 1];               // in scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:46
     let mut _2: &i32;                    // in scope 0 at $DIR/const-promotion-extern-static.rs:13:32: 13:45
     let mut _3: *const i32;              // in scope 0 at $DIR/const-promotion-extern-static.rs:13:42: 13:43
@@ -16,8 +16,8 @@ promoted[0] in FOO: &[&i32; 1] = {
                                          // + literal: Const { ty: *const i32, val: Value(Scalar(alloc3)) }
         _2 = &(*_3);                     // scope 0 at $DIR/const-promotion-extern-static.rs:13:41: 13:43
         _1 = [move _2];                  // scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:46
-        _0 = &_1;                        // scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:46
-        return;                          // scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:46
+        _0 = &_1;                        // scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:55
+        return;                          // scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:55
     }
 }
 

src/test/mir-opt/const_promotion_extern_static.FOO.PromoteTemps.diff

@@ -3,23 +3,23 @@
 
   static mut FOO: *const &i32 = {
       let mut _0: *const &i32;             // return place in scope 0 at $DIR/const-promotion-extern-static.rs:13:17: 13:28
-      let mut _1: &[&i32];                 // in scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:46
-      let mut _2: &[&i32; 1];              // in scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:46
+      let mut _1: &[&i32];                 // in scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:55
+      let mut _2: &[&i32; 1];              // in scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:55
       let _3: [&i32; 1];                   // in scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:46
       let mut _4: &i32;                    // in scope 0 at $DIR/const-promotion-extern-static.rs:13:32: 13:45
       let _5: *const i32;                  // in scope 0 at $DIR/const-promotion-extern-static.rs:13:42: 13:43
-+     let mut _6: &[&i32; 1];              // in scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:46
++     let mut _6: &[&i32; 1];              // in scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:55
       scope 1 {
       }
 
       bb0: {
-          StorageLive(_1);                 // scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:46
-          StorageLive(_2);                 // scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:46
+          StorageLive(_1);                 // scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:55
+          StorageLive(_2);                 // scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:55
 -         StorageLive(_3);                 // scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:46
 -         StorageLive(_4);                 // scope 0 at $DIR/const-promotion-extern-static.rs:13:32: 13:45
 -         StorageLive(_5);                 // scope 1 at $DIR/const-promotion-extern-static.rs:13:42: 13:43
 -         _5 = const {alloc3: *const i32}; // scope 1 at $DIR/const-promotion-extern-static.rs:13:42: 13:43
-+         _6 = const FOO::promoted[0];     // scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:46
++         _6 = const FOO::promoted[0];     // scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:55
                                            // ty::Const
 -                                          // + ty: *const i32
 -                                          // + val: Value(Scalar(alloc3))
@@ -30,11 +30,11 @@
 -                                          // + literal: Const { ty: *const i32, val: Value(Scalar(alloc3)) }
 -         _4 = &(*_5);                     // scope 1 at $DIR/const-promotion-extern-static.rs:13:41: 13:43
 -         _3 = [move _4];                  // scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:46
--         _2 = &_3;                        // scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:46
-+                                          // + span: $DIR/const-promotion-extern-static.rs:13:31: 13:46
+-         _2 = &_3;                        // scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:55
++                                          // + span: $DIR/const-promotion-extern-static.rs:13:31: 13:55
 +                                          // + literal: Const { ty: &[&i32; 1], val: Unevaluated(Unevaluated { def: WithOptConstParam { did: DefId(0:7 ~ const_promotion_extern_static[55e6]::FOO), const_param_did: None }, substs_: Some([]), promoted: Some(promoted[0]) }) }
-+         _2 = &(*_6);                     // scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:46
-          _1 = move _2 as &[&i32] (Pointer(Unsize)); // scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:46
++         _2 = &(*_6);                     // scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:55
+          _1 = move _2 as &[&i32] (Pointer(Unsize)); // scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:55
 -         StorageDead(_4);                 // scope 0 at $DIR/const-promotion-extern-static.rs:13:45: 13:46
           StorageDead(_2);                 // scope 0 at $DIR/const-promotion-extern-static.rs:13:45: 13:46
           _0 = core::slice::<impl [&i32]>::as_ptr(move _1) -> [return: bb1, unwind: bb2]; // scope 0 at $DIR/const-promotion-extern-static.rs:13:31: 13:55

src/test/mir-opt/deduplicate_blocks.is_line_doc_comment_2.DeduplicateBlocks.diff

@@ -5,7 +5,7 @@
       debug s => _1;                       // in scope 0 at $DIR/deduplicate_blocks.rs:2:36: 2:37
       let mut _0: bool;                    // return place in scope 0 at $DIR/deduplicate_blocks.rs:2:48: 2:52
       let mut _2: &[u8];                   // in scope 0 at $DIR/deduplicate_blocks.rs:3:11: 3:23
-      let mut _3: &str;                    // in scope 0 at $DIR/deduplicate_blocks.rs:3:11: 3:12
+      let mut _3: &str;                    // in scope 0 at $DIR/deduplicate_blocks.rs:3:11: 3:23
       let mut _4: usize;                   // in scope 0 at $DIR/deduplicate_blocks.rs:5:9: 5:31
       let mut _5: bool;                    // in scope 0 at $DIR/deduplicate_blocks.rs:5:9: 5:31
       let mut _6: usize;                   // in scope 0 at $DIR/deduplicate_blocks.rs:4:9: 4:37
@@ -19,8 +19,8 @@
 
       bb0: {
           StorageLive(_2);                 // scope 0 at $DIR/deduplicate_blocks.rs:3:11: 3:23
-          StorageLive(_3);                 // scope 0 at $DIR/deduplicate_blocks.rs:3:11: 3:12
-          _3 = _1;                         // scope 0 at $DIR/deduplicate_blocks.rs:3:11: 3:12
+          StorageLive(_3);                 // scope 0 at $DIR/deduplicate_blocks.rs:3:11: 3:23
+          _3 = _1;                         // scope 0 at $DIR/deduplicate_blocks.rs:3:11: 3:23
           StorageLive(_8);                 // scope 2 at $DIR/deduplicate_blocks.rs:3:11: 3:23
           _8 = _3;                         // scope 2 at $DIR/deduplicate_blocks.rs:3:11: 3:23
 -         _2 = transmute::<&str, &[u8]>(move _8) -> bb14; // scope 2 at $DIR/deduplicate_blocks.rs:3:11: 3:23

src/test/mir-opt/funky_arms.float_to_exponential_common.ConstProp.diff

@@ -7,9 +7,9 @@
       debug upper => _3;                   // in scope 0 at $DIR/funky_arms.rs:11:69: 11:74
       let mut _0: std::result::Result<(), std::fmt::Error>; // return place in scope 0 at $DIR/funky_arms.rs:11:85: 11:91
       let _4: bool;                        // in scope 0 at $DIR/funky_arms.rs:15:9: 15:19
-      let mut _5: &std::fmt::Formatter;    // in scope 0 at $DIR/funky_arms.rs:15:22: 15:25
+      let mut _5: &std::fmt::Formatter;    // in scope 0 at $DIR/funky_arms.rs:15:22: 15:37
       let mut _7: std::option::Option<usize>; // in scope 0 at $DIR/funky_arms.rs:24:30: 24:45
-      let mut _8: &std::fmt::Formatter;    // in scope 0 at $DIR/funky_arms.rs:24:30: 24:33
+      let mut _8: &std::fmt::Formatter;    // in scope 0 at $DIR/funky_arms.rs:24:30: 24:45
       let mut _9: isize;                   // in scope 0 at $DIR/funky_arms.rs:24:12: 24:27
       let mut _11: &mut std::fmt::Formatter; // in scope 0 at $DIR/funky_arms.rs:26:43: 26:46
       let mut _12: &T;                     // in scope 0 at $DIR/funky_arms.rs:26:48: 26:51
@@ -36,8 +36,8 @@
 
       bb0: {
           StorageLive(_4);                 // scope 0 at $DIR/funky_arms.rs:15:9: 15:19
-          StorageLive(_5);                 // scope 0 at $DIR/funky_arms.rs:15:22: 15:25
-          _5 = &(*_1);                     // scope 0 at $DIR/funky_arms.rs:15:22: 15:25
+          StorageLive(_5);                 // scope 0 at $DIR/funky_arms.rs:15:22: 15:37
+          _5 = &(*_1);                     // scope 0 at $DIR/funky_arms.rs:15:22: 15:37
           _4 = Formatter::sign_plus(move _5) -> bb1; // scope 0 at $DIR/funky_arms.rs:15:22: 15:37
                                            // mir::Constant
                                            // + span: $DIR/funky_arms.rs:15:26: 15:35
@@ -62,8 +62,8 @@
 
       bb4: {
           StorageLive(_7);                 // scope 2 at $DIR/funky_arms.rs:24:30: 24:45
-          StorageLive(_8);                 // scope 2 at $DIR/funky_arms.rs:24:30: 24:33
-          _8 = &(*_1);                     // scope 2 at $DIR/funky_arms.rs:24:30: 24:33
+          StorageLive(_8);                 // scope 2 at $DIR/funky_arms.rs:24:30: 24:45
+          _8 = &(*_1);                     // scope 2 at $DIR/funky_arms.rs:24:30: 24:45
           _7 = Formatter::precision(move _8) -> bb5; // scope 2 at $DIR/funky_arms.rs:24:30: 24:45
                                            // mir::Constant
                                            // + span: $DIR/funky_arms.rs:24:34: 24:43