diff options
Diffstat (limited to 'compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs')
-rw-r--r-- | compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs | 48 |
1 files changed, 26 insertions, 22 deletions
diff --git a/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs b/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs index d6dd0f017..b58685e89 100644 --- a/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs +++ b/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs @@ -19,21 +19,18 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> { /// Converts an evaluated constant to a pattern (if possible). /// This means aggregate values (like structs and enums) are converted /// to a pattern that matches the value (as if you'd compared via structural equality). - #[instrument(level = "debug", skip(self))] + #[instrument(level = "debug", skip(self), ret)] pub(super) fn const_to_pat( &self, cv: mir::ConstantKind<'tcx>, id: hir::HirId, span: Span, mir_structural_match_violation: bool, - ) -> Pat<'tcx> { - let pat = self.tcx.infer_ctxt().enter(|infcx| { + ) -> Box<Pat<'tcx>> { + self.tcx.infer_ctxt().enter(|infcx| { let mut convert = ConstToPat::new(self, id, span, infcx); convert.to_pat(cv, mir_structural_match_violation) - }); - - debug!(?pat); - pat + }) } } @@ -159,7 +156,7 @@ impl<'a, 'tcx> ConstToPat<'a, 'tcx> { &mut self, cv: mir::ConstantKind<'tcx>, mir_structural_match_violation: bool, - ) -> Pat<'tcx> { + ) -> Box<Pat<'tcx>> { trace!(self.treat_byte_string_as_slice); // This method is just a wrapper handling a validity check; the heavy lifting is // performed by the recursive `recur` method, which is not meant to be @@ -168,7 +165,14 @@ impl<'a, 'tcx> ConstToPat<'a, 'tcx> { // once indirect_structural_match is a full fledged error, this // level of indirection can be eliminated - let inlined_const_as_pat = self.recur(cv, mir_structural_match_violation).unwrap(); + let inlined_const_as_pat = + self.recur(cv, mir_structural_match_violation).unwrap_or_else(|_| { + Box::new(Pat { + span: self.span, + ty: cv.ty(), + kind: PatKind::Constant { value: cv }, + }) + }); if self.include_lint_checks && !self.saw_const_match_error.get() { // If we were able to successfully convert the const to some pat, @@ -269,7 +273,7 @@ impl<'a, 'tcx> ConstToPat<'a, 'tcx> { &self, cv: mir::ConstantKind<'tcx>, mir_structural_match_violation: bool, - ) -> Result<Pat<'tcx>, FallbackToConstRef> { + ) -> Result<Box<Pat<'tcx>>, FallbackToConstRef> { let id = self.id; let span = self.span; let tcx = self.tcx(); @@ -396,7 +400,7 @@ impl<'a, 'tcx> ConstToPat<'a, 'tcx> { .map(|val| self.recur(*val, false)) .collect::<Result<_, _>>()?, slice: None, - suffix: Vec::new(), + suffix: Box::new([]), }, ty::Ref(_, pointee_ty, ..) => match *pointee_ty.kind() { // These are not allowed and will error elsewhere anyway. @@ -423,8 +427,8 @@ impl<'a, 'tcx> ConstToPat<'a, 'tcx> { let old = self.behind_reference.replace(true); let array = tcx.deref_mir_constant(self.param_env.and(cv)); let val = PatKind::Deref { - subpattern: Pat { - kind: Box::new(PatKind::Array { + subpattern: Box::new(Pat { + kind: PatKind::Array { prefix: tcx .destructure_mir_constant(param_env, array) .fields @@ -432,11 +436,11 @@ impl<'a, 'tcx> ConstToPat<'a, 'tcx> { .map(|val| self.recur(*val, false)) .collect::<Result<_, _>>()?, slice: None, - suffix: vec![], - }), + suffix: Box::new([]), + }, span, ty: *pointee_ty, - }, + }), }; self.behind_reference.set(old); val @@ -449,8 +453,8 @@ impl<'a, 'tcx> ConstToPat<'a, 'tcx> { let old = self.behind_reference.replace(true); let array = tcx.deref_mir_constant(self.param_env.and(cv)); let val = PatKind::Deref { - subpattern: Pat { - kind: Box::new(PatKind::Slice { + subpattern: Box::new(Pat { + kind: PatKind::Slice { prefix: tcx .destructure_mir_constant(param_env, array) .fields @@ -458,11 +462,11 @@ impl<'a, 'tcx> ConstToPat<'a, 'tcx> { .map(|val| self.recur(*val, false)) .collect::<Result<_, _>>()?, slice: None, - suffix: vec![], - }), + suffix: Box::new([]), + }, span, ty: tcx.mk_slice(elem_ty), - }, + }), }; self.behind_reference.set(old); val @@ -596,6 +600,6 @@ impl<'a, 'tcx> ConstToPat<'a, 'tcx> { ); } - Ok(Pat { span, ty: cv.ty(), kind: Box::new(kind) }) + Ok(Box::new(Pat { span, ty: cv.ty(), kind })) } } |