test: Visit debuginfos when needed

Author: dianqk

compiler/rustc_middle/src/mir/visit.rs

@@ -68,6 +68,8 @@ use crate::ty::CanonicalUserTypeAnnotation;
 macro_rules! make_mir_visitor {
     ($visitor_trait_name:ident, $($mutability:ident)?) => {
         pub trait $visitor_trait_name<'tcx> {
+            const VISIT_DEBUG_INFO: bool = false;
+
             // Override these, and call `self.super_xxx` to revert back to the
             // default behavior.
 
@@ -100,7 +102,9 @@ macro_rules! make_mir_visitor {
                 stmt_debuginfo: & $($mutability)? [StmtDebugInfo<'tcx>],
                 location: Location
             ) {
-                self.super_statement_debuginfos(stmt_debuginfo, location);
+                if Self::VISIT_DEBUG_INFO {
+                    self.super_statement_debuginfos(stmt_debuginfo, location);
+                }
             }
 
             fn visit_statement_debuginfo(

compiler/rustc_mir_dataflow/src/debuginfo.rs

@@ -12,6 +12,8 @@ pub fn debuginfo_locals(body: &Body<'_>) -> DenseBitSet<Local> {
 struct DebuginfoLocals(DenseBitSet<Local>);
 
 impl Visitor<'_> for DebuginfoLocals {
+    const VISIT_DEBUG_INFO: bool = true;
+
     fn visit_local(&mut self, local: Local, place_context: PlaceContext, _: Location) {
         if place_context == PlaceContext::NonUse(NonUseContext::VarDebugInfo) {
             self.0.insert(local);

compiler/rustc_mir_transform/src/copy_prop.rs

@@ -104,6 +104,8 @@ struct Replacer<'a, 'tcx> {
 }
 
 impl<'tcx> MutVisitor<'tcx> for Replacer<'_, 'tcx> {
+    const VISIT_DEBUG_INFO: bool = true;
+
     fn tcx(&self) -> TyCtxt<'tcx> {
         self.tcx
     }

compiler/rustc_mir_transform/src/dest_prop.rs

@@ -292,6 +292,7 @@ struct Merger<'tcx> {
 }
 
 impl<'tcx> MutVisitor<'tcx> for Merger<'tcx> {
+    const VISIT_DEBUG_INFO: bool = true;
     fn tcx(&self) -> TyCtxt<'tcx> {
         self.tcx
     }

compiler/rustc_mir_transform/src/gvn.rs

@@ -1749,6 +1749,8 @@ impl<'tcx> VnState<'_, 'tcx> {
 }
 
 impl<'tcx> MutVisitor<'tcx> for VnState<'_, 'tcx> {
+    const VISIT_DEBUG_INFO: bool = true;
+
     fn tcx(&self) -> TyCtxt<'tcx> {
         self.tcx
     }

compiler/rustc_mir_transform/src/inline.rs

@@ -1230,6 +1230,8 @@ impl Integrator<'_, '_> {
 }
 
 impl<'tcx> MutVisitor<'tcx> for Integrator<'_, 'tcx> {
+    const VISIT_DEBUG_INFO: bool = true;
+
     fn tcx(&self) -> TyCtxt<'tcx> {
         self.tcx
     }

compiler/rustc_mir_transform/src/prettify.rs

@@ -148,6 +148,8 @@ struct LocalUpdater<'tcx> {
 }
 
 impl<'tcx> MutVisitor<'tcx> for LocalUpdater<'tcx> {
+    const VISIT_DEBUG_INFO: bool = true;
+
     fn tcx(&self) -> TyCtxt<'tcx> {
         self.tcx
     }

compiler/rustc_mir_transform/src/ref_prop.rs

@@ -284,6 +284,8 @@ fn compute_replacement<'tcx>(
     where
         F: FnMut(Place<'tcx>, Location) -> bool,
     {
+        const VISIT_DEBUG_INFO: bool = true;
+
         fn visit_place(&mut self, place: &Place<'tcx>, ctxt: PlaceContext, loc: Location) {
             if matches!(ctxt, PlaceContext::NonUse(_)) {
                 // There is no need to check liveness for non-uses.
@@ -354,6 +356,8 @@ struct Replacer<'tcx> {
 }
 
 impl<'tcx> MutVisitor<'tcx> for Replacer<'tcx> {
+    const VISIT_DEBUG_INFO: bool = true;
+
     fn tcx(&self) -> TyCtxt<'tcx> {
         self.tcx
     }

compiler/rustc_mir_transform/src/simplify.rs

@@ -669,6 +669,8 @@ struct LocalUpdater<'tcx> {
 }
 
 impl<'tcx> MutVisitor<'tcx> for LocalUpdater<'tcx> {
+    const VISIT_DEBUG_INFO: bool = true;
+
     fn tcx(&self) -> TyCtxt<'tcx> {
         self.tcx
     }
@@ -709,6 +711,8 @@ impl UsedInStmtLocals {
 }
 
 impl<'tcx> Visitor<'tcx> for UsedInStmtLocals {
+    const VISIT_DEBUG_INFO: bool = true;
+
     fn visit_local(&mut self, local: Local, context: PlaceContext, _: Location) {
         if matches!(context, PlaceContext::NonUse(_)) {
             return;

compiler/rustc_mir_transform/src/validate.rs

@@ -280,6 +280,7 @@ impl<'a, 'tcx> CfgChecker<'a, 'tcx> {
 }
 
 impl<'a, 'tcx> Visitor<'tcx> for CfgChecker<'a, 'tcx> {
+    const VISIT_DEBUG_INFO: bool = true;
     fn visit_local(&mut self, local: Local, _context: PlaceContext, location: Location) {
         if self.body.local_decls.get(local).is_none() {
             self.fail(
@@ -627,6 +628,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
 }
 
 impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
+    const VISIT_DEBUG_INFO: bool = true;
     fn visit_operand(&mut self, operand: &Operand<'tcx>, location: Location) {
         // This check is somewhat expensive, so only run it when -Zvalidate-mir is passed.
         if self.tcx.sess.opts.unstable_opts.validate_mir