MIR validation: add comment explaining the limitations of CfgChecker

RalfJung · RalfJung · commit dcde4c51fa30 · 2025-02-06T10:06:07.000+01:00
diff --git a/compiler/rustc_mir_transform/src/validate.rs b/compiler/rustc_mir_transform/src/validate.rs
@@ -97,6 +97,11 @@ impl<'tcx> crate::MirPass<'tcx> for Validator {
     }
 }
 
+/// This checker covers basic properties of the control-flow graph, (dis)allowed statements and terminators.
+/// Everything checked here must be stable under substitution of generic parameters.
+///
+/// Everything that depends on types, or otherwise can be affected by generic paramters,
+/// muts be checked in `TypeChecker`.
 struct CfgChecker<'a, 'tcx> {
     when: &'a str,
     body: &'a Body<'tcx>,

Original file line number	Diff line number	Diff line change
`@@ -97,6 +97,11 @@ impl<'tcx> crate::MirPass<'tcx> for Validator {`
`97`	`97`	`}`
`98`	`98`	`}`
`99`	`99`
	`100`	`+/// This checker covers basic properties of the control-flow graph, (dis)allowed statements and terminators.`
	`101`	`+/// Everything checked here must be stable under substitution of generic parameters.`
	`102`	`+///`
	`103`	`+/// Everything that depends on types, or otherwise can be affected by generic paramters,`
	`104`	+/// muts be checked in `TypeChecker`.
`100`	`105`	`struct CfgChecker<'a, 'tcx> {`
`101`	`106`	`when: &'a str,`
`102`	`107`	`body: &'a Body<'tcx>,`