diff options
Diffstat (limited to 'compiler/rustc_mir_build/src/thir/pattern/mod.rs')
| -rw-r--r-- | compiler/rustc_mir_build/src/thir/pattern/mod.rs | 99 |
1 files changed, 69 insertions, 30 deletions
diff --git a/compiler/rustc_mir_build/src/thir/pattern/mod.rs b/compiler/rustc_mir_build/src/thir/pattern/mod.rs index 48a231a6c..3a6ef87c9 100644 --- a/compiler/rustc_mir_build/src/thir/pattern/mod.rs +++ b/compiler/rustc_mir_build/src/thir/pattern/mod.rs @@ -2,14 +2,16 @@ mod check_match; mod const_to_pat; -mod deconstruct_pat; +pub(crate) mod deconstruct_pat; mod usefulness; pub(crate) use self::check_match::check_match; +pub(crate) use self::usefulness::MatchCheckCtxt; +use crate::errors::*; use crate::thir::util::UserAnnotatedTyHelpers; -use rustc_errors::struct_span_err; +use rustc_errors::error_code; use rustc_hir as hir; use rustc_hir::def::{CtorOf, DefKind, Res}; use rustc_hir::pat_util::EnumerateAndAdjustIterator; @@ -127,10 +129,20 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> { hi: mir::ConstantKind<'tcx>, end: RangeEnd, span: Span, + lo_expr: Option<&hir::Expr<'tcx>>, + hi_expr: Option<&hir::Expr<'tcx>>, ) -> PatKind<'tcx> { assert_eq!(lo.ty(), ty); assert_eq!(hi.ty(), ty); let cmp = compare_const_vals(self.tcx, lo, hi, self.param_env); + let max = || { + self.tcx + .layout_of(self.param_env.with_reveal_all_normalized(self.tcx).and(ty)) + .ok() + .unwrap() + .size + .unsigned_int_max() + }; match (end, cmp) { // `x..y` where `x < y`. // Non-empty because the range includes at least `x`. @@ -139,13 +151,27 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> { } // `x..y` where `x >= y`. The range is empty => error. (RangeEnd::Excluded, _) => { - struct_span_err!( - self.tcx.sess, - span, - E0579, - "lower range bound must be less than upper" - ) - .emit(); + let mut lower_overflow = false; + let mut higher_overflow = false; + if let Some(hir::Expr { kind: hir::ExprKind::Lit(lit), .. }) = lo_expr + && let rustc_ast::ast::LitKind::Int(val, _) = lit.node + { + if lo.eval_bits(self.tcx, self.param_env, ty) != val { + lower_overflow = true; + self.tcx.sess.emit_err(LiteralOutOfRange { span: lit.span, ty, max: max() }); + } + } + if let Some(hir::Expr { kind: hir::ExprKind::Lit(lit), .. }) = hi_expr + && let rustc_ast::ast::LitKind::Int(val, _) = lit.node + { + if hi.eval_bits(self.tcx, self.param_env, ty) != val { + higher_overflow = true; + self.tcx.sess.emit_err(LiteralOutOfRange { span: lit.span, ty, max: max() }); + } + } + if !lower_overflow && !higher_overflow { + self.tcx.sess.emit_err(LowerRangeBoundMustBeLessThanUpper { span }); + } PatKind::Wild } // `x..=y` where `x == y`. @@ -156,23 +182,34 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> { } // `x..=y` where `x > y` hence the range is empty => error. (RangeEnd::Included, _) => { - let mut err = struct_span_err!( - self.tcx.sess, - span, - E0030, - "lower range bound must be less than or equal to upper" - ); - err.span_label(span, "lower bound larger than upper bound"); - if self.tcx.sess.teach(&err.get_code().unwrap()) { - err.note( - "When matching against a range, the compiler \ - verifies that the range is non-empty. Range \ - patterns include both end-points, so this is \ - equivalent to requiring the start of the range \ - to be less than or equal to the end of the range.", - ); + let mut lower_overflow = false; + let mut higher_overflow = false; + if let Some(hir::Expr { kind: hir::ExprKind::Lit(lit), .. }) = lo_expr + && let rustc_ast::ast::LitKind::Int(val, _) = lit.node + { + if lo.eval_bits(self.tcx, self.param_env, ty) != val { + lower_overflow = true; + self.tcx.sess.emit_err(LiteralOutOfRange { span: lit.span, ty, max: max() }); + } + } + if let Some(hir::Expr { kind: hir::ExprKind::Lit(lit), .. }) = hi_expr + && let rustc_ast::ast::LitKind::Int(val, _) = lit.node + { + if hi.eval_bits(self.tcx, self.param_env, ty) != val { + higher_overflow = true; + self.tcx.sess.emit_err(LiteralOutOfRange { span: lit.span, ty, max: max() }); + } + } + if !lower_overflow && !higher_overflow { + self.tcx.sess.emit_err(LowerRangeBoundMustBeLessThanOrEqualToUpper { + span, + teach: if self.tcx.sess.teach(&error_code!(E0030)) { + Some(()) + } else { + None + }, + }); } - err.emit(); PatKind::Wild } } @@ -218,7 +255,9 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> { let (lp, hp) = (lo.as_ref().map(|(x, _)| x), hi.as_ref().map(|(x, _)| x)); let mut kind = match self.normalize_range_pattern_ends(ty, lp, hp) { - Some((lc, hc)) => self.lower_pattern_range(ty, lc, hc, end, lo_span), + Some((lc, hc)) => { + self.lower_pattern_range(ty, lc, hc, end, lo_span, lo_expr, hi_expr) + } None => { let msg = &format!( "found bad range pattern `{:?}` outside of error recovery", @@ -501,7 +540,7 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> { } Err(_) => { - self.tcx.sess.span_err(span, "could not evaluate constant pattern"); + self.tcx.sess.emit_err(CouldNotEvalConstPattern { span }); return pat_from_kind(PatKind::Wild); } }; @@ -548,11 +587,11 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> { Err(ErrorHandled::TooGeneric) => { // While `Reported | Linted` cases will have diagnostics emitted already // it is not true for TooGeneric case, so we need to give user more information. - self.tcx.sess.span_err(span, "constant pattern depends on a generic parameter"); + self.tcx.sess.emit_err(ConstPatternDependsOnGenericParameter { span }); pat_from_kind(PatKind::Wild) } Err(_) => { - self.tcx.sess.span_err(span, "could not evaluate constant pattern"); + self.tcx.sess.emit_err(CouldNotEvalConstPattern { span }); pat_from_kind(PatKind::Wild) } } @@ -584,7 +623,7 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> { mir::ConstantKind::Val(_, _) => self.const_to_pat(value, id, span, false).kind, mir::ConstantKind::Unevaluated(..) => { // If we land here it means the const can't be evaluated because it's `TooGeneric`. - self.tcx.sess.span_err(span, "constant pattern depends on a generic parameter"); + self.tcx.sess.emit_err(ConstPatternDependsOnGenericParameter { span }); return PatKind::Wild; } } |