inline: Drop debuginfos if drop var debuginfos

dianqk · dianqk · commit 15c968ac3980 · 2025-06-20T15:16:23.000+08:00
diff --git a/compiler/rustc_middle/src/mir/mod.rs b/compiler/rustc_middle/src/mir/mod.rs
@@ -1430,6 +1430,13 @@ impl<'tcx> BasicBlockData<'tcx> {
     pub fn strip_nops(&mut self) {
         self.retain_statements(|stmt| !matches!(stmt.kind, StatementKind::Nop))
     }
+
+    pub fn drop_debuginfo(&mut self) {
+        self.after_last_stmt_debuginfos = Vec::new();
+        for stmt in self.statements.iter_mut() {
+            stmt.debuginfos = Vec::new();
+        }
+    }
 }
 
 ///////////////////////////////////////////////////////////////////////////
diff --git a/compiler/rustc_mir_transform/src/inline.rs b/compiler/rustc_mir_transform/src/inline.rs
@@ -992,6 +992,10 @@ fn inline_call<'tcx, I: Inliner<'tcx>>(
         // people working on rust can build with or without debuginfo while
         // still getting consistent results from the mir-opt tests.
         caller_body.var_debug_info.append(&mut callee_body.var_debug_info);
+    } else {
+        for bb in callee_body.basic_blocks_mut() {
+            bb.drop_debuginfo();
+        }
     }
     caller_body.basic_blocks_mut().append(callee_body.basic_blocks_mut());
 
diff --git a/tests/mir-opt/inline/inline_shims.drop.Inline.panic-abort.diff b/tests/mir-opt/inline/inline_shims.drop.Inline.panic-abort.diff
@@ -65,8 +65,6 @@
 +         StorageLive(_12);
 +         StorageLive(_8);
 +         StorageLive(_9);
-+         // DBG: AssignRef(_11, ((*_6).0: alloc::raw_vec::RawVec<A>))
-+         // DBG: AssignRef(_12, (((*_6).0: alloc::raw_vec::RawVec<A>).0: alloc::raw_vec::RawVecInner))
 +         StorageLive(_13);
 +         _13 = copy (((((*_6).0: alloc::raw_vec::RawVec<A>).0: alloc::raw_vec::RawVecInner).0: std::ptr::Unique<u8>).0: std::ptr::NonNull<u8>);
 +         _9 = copy _13 as *mut A (Transmute);
diff --git a/tests/mir-opt/inline_coroutine_body.run2-{closure#0}.Inline.panic-abort.diff b/tests/mir-opt/inline_coroutine_body.run2-{closure#0}.Inline.panic-abort.diff
@@ -233,10 +233,7 @@
 +         StorageLive(_50);
 +         StorageLive(_42);
 +         StorageLive(_43);
-+         // DBG: AssignRef(_46, _19)
-+         // DBG: AssignRef(_47, (_19.0: &mut std::future::Ready<()>))
 +         _45 = copy (_19.0: &mut std::future::Ready<()>);
-+         // DBG: AssignRef(_44, ((*_45).0: std::option::Option<()>))
 +         StorageLive(_48);
 +         _48 = Option::<()>::None;
 +         _43 = copy ((*_45).0: std::option::Option<()>);
diff --git a/tests/mir-opt/inline_coroutine_body.run2-{closure#0}.Inline.panic-unwind.diff b/tests/mir-opt/inline_coroutine_body.run2-{closure#0}.Inline.panic-unwind.diff
@@ -250,10 +250,7 @@
 +         StorageLive(_52);
 +         StorageLive(_44);
 +         StorageLive(_45);
-+         // DBG: AssignRef(_48, _19)
-+         // DBG: AssignRef(_49, (_19.0: &mut std::future::Ready<()>))
 +         _47 = copy (_19.0: &mut std::future::Ready<()>);
-+         // DBG: AssignRef(_46, ((*_47).0: std::option::Option<()>))
 +         StorageLive(_50);
 +         _50 = Option::<()>::None;
 +         _45 = copy ((*_47).0: std::option::Option<()>);
diff --git a/tests/mir-opt/issues/issue_59352.num_to_digit.PreCodegen.after.32bit.panic-abort.mir b/tests/mir-opt/issues/issue_59352.num_to_digit.PreCodegen.after.32bit.panic-abort.mir
@@ -6,7 +6,6 @@ fn num_to_digit(_1: char) -> u32 {
     let mut _4: std::option::Option<u32>;
     scope 1 (inlined char::methods::<impl char>::is_digit) {
         let _2: std::option::Option<u32>;
-        let mut _7: &std::option::Option<u32>;
         scope 2 (inlined Option::<u32>::is_some) {
             let mut _3: isize;
         }
@@ -19,17 +18,14 @@ fn num_to_digit(_1: char) -> u32 {
     }
 
     bb0: {
-        StorageLive(_7);
         StorageLive(_2);
         _2 = char::methods::<impl char>::to_digit(copy _1, const 8_u32) -> [return: bb1, unwind unreachable];
     }
 
     bb1: {
-        // DBG: AssignRef(_7, _2)
         StorageLive(_3);
         _3 = discriminant(_2);
         StorageDead(_2);
-        StorageDead(_7);
         switchInt(move _3) -> [1: bb2, otherwise: bb7];
     }
 
diff --git a/tests/mir-opt/issues/issue_59352.num_to_digit.PreCodegen.after.32bit.panic-unwind.mir b/tests/mir-opt/issues/issue_59352.num_to_digit.PreCodegen.after.32bit.panic-unwind.mir
@@ -6,7 +6,6 @@ fn num_to_digit(_1: char) -> u32 {
     let mut _4: std::option::Option<u32>;
     scope 1 (inlined char::methods::<impl char>::is_digit) {
         let _2: std::option::Option<u32>;
-        let mut _7: &std::option::Option<u32>;
         scope 2 (inlined Option::<u32>::is_some) {
             let mut _3: isize;
         }
@@ -19,17 +18,14 @@ fn num_to_digit(_1: char) -> u32 {
     }
 
     bb0: {
-        StorageLive(_7);
         StorageLive(_2);
         _2 = char::methods::<impl char>::to_digit(copy _1, const 8_u32) -> [return: bb1, unwind continue];
     }
 
     bb1: {
-        // DBG: AssignRef(_7, _2)
         StorageLive(_3);
         _3 = discriminant(_2);
         StorageDead(_2);
-        StorageDead(_7);
         switchInt(move _3) -> [1: bb2, otherwise: bb7];
     }
 
diff --git a/tests/mir-opt/issues/issue_59352.num_to_digit.PreCodegen.after.64bit.panic-abort.mir b/tests/mir-opt/issues/issue_59352.num_to_digit.PreCodegen.after.64bit.panic-abort.mir
@@ -6,7 +6,6 @@ fn num_to_digit(_1: char) -> u32 {
     let mut _4: std::option::Option<u32>;
     scope 1 (inlined char::methods::<impl char>::is_digit) {
         let _2: std::option::Option<u32>;
-        let mut _7: &std::option::Option<u32>;
         scope 2 (inlined Option::<u32>::is_some) {
             let mut _3: isize;
         }
@@ -19,17 +18,14 @@ fn num_to_digit(_1: char) -> u32 {
     }
 
     bb0: {
-        StorageLive(_7);
         StorageLive(_2);
         _2 = char::methods::<impl char>::to_digit(copy _1, const 8_u32) -> [return: bb1, unwind unreachable];
     }
 
     bb1: {
-        // DBG: AssignRef(_7, _2)
         StorageLive(_3);
         _3 = discriminant(_2);
         StorageDead(_2);
-        StorageDead(_7);
         switchInt(move _3) -> [1: bb2, otherwise: bb7];
     }
 
diff --git a/tests/mir-opt/issues/issue_59352.num_to_digit.PreCodegen.after.64bit.panic-unwind.mir b/tests/mir-opt/issues/issue_59352.num_to_digit.PreCodegen.after.64bit.panic-unwind.mir
@@ -6,7 +6,6 @@ fn num_to_digit(_1: char) -> u32 {
     let mut _4: std::option::Option<u32>;
     scope 1 (inlined char::methods::<impl char>::is_digit) {
         let _2: std::option::Option<u32>;
-        let mut _7: &std::option::Option<u32>;
         scope 2 (inlined Option::<u32>::is_some) {
             let mut _3: isize;
         }
@@ -19,17 +18,14 @@ fn num_to_digit(_1: char) -> u32 {
     }
 
     bb0: {
-        StorageLive(_7);
         StorageLive(_2);
         _2 = char::methods::<impl char>::to_digit(copy _1, const 8_u32) -> [return: bb1, unwind continue];
     }
 
     bb1: {
-        // DBG: AssignRef(_7, _2)
         StorageLive(_3);
         _3 = discriminant(_2);
         StorageDead(_2);
-        StorageDead(_7);
         switchInt(move _3) -> [1: bb2, otherwise: bb7];
     }
 
diff --git a/tests/mir-opt/pre-codegen/checked_ops.step_forward.PreCodegen.after.panic-abort.mir b/tests/mir-opt/pre-codegen/checked_ops.step_forward.PreCodegen.after.panic-abort.mir
@@ -6,8 +6,6 @@ fn step_forward(_1: u16, _2: usize) -> u16 {
     let mut _0: u16;
     scope 1 (inlined <u16 as Step>::forward) {
         let mut _8: u16;
-        let mut _9: &std::option::Option<u16>;
-        let _10: std::option::Option<u16>;
         scope 2 {
         }
         scope 3 (inlined <u16 as Step>::forward_checked) {
@@ -34,8 +32,6 @@ fn step_forward(_1: u16, _2: usize) -> u16 {
     }
 
     bb0: {
-        StorageLive(_9);
-        StorageLive(_10);
         StorageLive(_4);
         StorageLive(_3);
         _3 = Gt(copy _2, const 65535_usize);
@@ -55,7 +51,6 @@ fn step_forward(_1: u16, _2: usize) -> u16 {
     bb2: {
         StorageDead(_5);
         StorageDead(_6);
-        // DBG: AssignRef(_9, _10)
         goto -> bb7;
     }
 
@@ -66,13 +61,11 @@ fn step_forward(_1: u16, _2: usize) -> u16 {
     bb4: {
         StorageDead(_5);
         StorageDead(_6);
-        // DBG: AssignRef(_9, _10)
         goto -> bb6;
     }
 
     bb5: {
         StorageDead(_3);
-        // DBG: AssignRef(_9, _10)
         goto -> bb6;
     }
 
@@ -86,8 +79,6 @@ fn step_forward(_1: u16, _2: usize) -> u16 {
         _0 = Add(copy _1, copy _8);
         StorageDead(_8);
         StorageDead(_4);
-        StorageDead(_10);
-        StorageDead(_9);
         return;
     }
 }
diff --git a/tests/mir-opt/pre-codegen/checked_ops.step_forward.PreCodegen.after.panic-unwind.mir b/tests/mir-opt/pre-codegen/checked_ops.step_forward.PreCodegen.after.panic-unwind.mir
@@ -6,8 +6,6 @@ fn step_forward(_1: u16, _2: usize) -> u16 {
     let mut _0: u16;
     scope 1 (inlined <u16 as Step>::forward) {
         let mut _8: u16;
-        let mut _9: &std::option::Option<u16>;
-        let _10: std::option::Option<u16>;
         scope 2 {
         }
         scope 3 (inlined <u16 as Step>::forward_checked) {
@@ -34,8 +32,6 @@ fn step_forward(_1: u16, _2: usize) -> u16 {
     }
 
     bb0: {
-        StorageLive(_9);
-        StorageLive(_10);
         StorageLive(_4);
         StorageLive(_3);
         _3 = Gt(copy _2, const 65535_usize);
@@ -55,7 +51,6 @@ fn step_forward(_1: u16, _2: usize) -> u16 {
     bb2: {
         StorageDead(_5);
         StorageDead(_6);
-        // DBG: AssignRef(_9, _10)
         goto -> bb7;
     }
 
@@ -66,13 +61,11 @@ fn step_forward(_1: u16, _2: usize) -> u16 {
     bb4: {
         StorageDead(_5);
         StorageDead(_6);
-        // DBG: AssignRef(_9, _10)
         goto -> bb6;
     }
 
     bb5: {
         StorageDead(_3);
-        // DBG: AssignRef(_9, _10)
         goto -> bb6;
     }
 
@@ -86,8 +79,6 @@ fn step_forward(_1: u16, _2: usize) -> u16 {
         _0 = Add(copy _1, copy _8);
         StorageDead(_8);
         StorageDead(_4);
-        StorageDead(_10);
-        StorageDead(_9);
         return;
     }
 }

Original file line number	Diff line number	Diff line change
`@@ -1430,6 +1430,13 @@ impl<'tcx> BasicBlockData<'tcx> {`
`1430`	`1430`	`pub fn strip_nops(&mut self) {`
`1431`	`1431`	`self.retain_statements(\|stmt\| !matches!(stmt.kind, StatementKind::Nop))`
`1432`	`1432`	`}`
	`1433`	`+`
	`1434`	`+ pub fn drop_debuginfo(&mut self) {`
	`1435`	`+ self.after_last_stmt_debuginfos = Vec::new();`
	`1436`	`+ for stmt in self.statements.iter_mut() {`
	`1437`	`+ stmt.debuginfos = Vec::new();`
	`1438`	`+ }`
	`1439`	`+ }`
`1433`	`1440`	`}`
`1434`	`1441`
`1435`	`1442`	`///////////////////////////////////////////////////////////////////////////`
Original file line number	Diff line number	Diff line change
`@@ -6,7 +6,6 @@ fn num_to_digit(_1: char) -> u32 {`
`6`	`6`	`let mut _4: std::option::Option<u32>;`
`7`	`7`	`scope 1 (inlined char::methods::<impl char>::is_digit) {`
`8`	`8`	`let _2: std::option::Option<u32>;`
`9`		`- let mut _7: &std::option::Option<u32>;`
`10`	`9`	`scope 2 (inlined Option::<u32>::is_some) {`
`11`	`10`	`let mut _3: isize;`
`12`	`11`	`}`
`@@ -19,17 +18,14 @@ fn num_to_digit(_1: char) -> u32 {`
`19`	`18`	`}`
`20`	`19`
`21`	`20`	`bb0: {`
`22`		`- StorageLive(_7);`
`23`	`21`	`StorageLive(_2);`
`24`	`22`	`_2 = char::methods::<impl char>::to_digit(copy _1, const 8_u32) -> [return: bb1, unwind unreachable];`
`25`	`23`	`}`
`26`	`24`
`27`	`25`	`bb1: {`
`28`		`- // DBG: AssignRef(_7, _2)`
`29`	`26`	`StorageLive(_3);`
`30`	`27`	`_3 = discriminant(_2);`
`31`	`28`	`StorageDead(_2);`
`32`		`- StorageDead(_7);`
`33`	`29`	`switchInt(move _3) -> [1: bb2, otherwise: bb7];`
`34`	`30`	`}`
`35`	`31`