rustc: Move eval_const_expr to its own mod

src/rustc/syntax/ast_util.rs

@@ -242,172 +242,6 @@ fn default_block(stmts1: [@stmt], expr1: option<@expr>, id1: node_id) ->
     {view_items: [], stmts: stmts1, expr: expr1, id: id1, rules: default_blk}
 }
 
-// FIXME this doesn't handle big integer/float literals correctly (nor does
-// the rest of our literal handling)
-enum const_val {
-    const_float(float),
-    const_int(i64),
-    const_uint(u64),
-    const_str(str),
-}
-
-// FIXME: issue #1417
-fn eval_const_expr(tcx: middle::ty::ctxt, e: @expr) -> const_val {
-    import middle::ty;
-    fn fromb(b: bool) -> const_val { const_int(b as i64) }
-    alt check e.node {
-      expr_unary(neg, inner) {
-        alt check eval_const_expr(tcx, inner) {
-          const_float(f) { const_float(-f) }
-          const_int(i) { const_int(-i) }
-          const_uint(i) { const_uint(-i) }
-        }
-      }
-      expr_unary(not, inner) {
-        alt check eval_const_expr(tcx, inner) {
-          const_int(i) { const_int(!i) }
-          const_uint(i) { const_uint(!i) }
-        }
-      }
-      expr_binary(op, a, b) {
-        alt check (eval_const_expr(tcx, a), eval_const_expr(tcx, b)) {
-          (const_float(a), const_float(b)) {
-            alt check op {
-              add { const_float(a + b) } subtract { const_float(a - b) }
-              mul { const_float(a * b) } div { const_float(a / b) }
-              rem { const_float(a % b) } eq { fromb(a == b) }
-              lt { fromb(a < b) } le { fromb(a <= b) } ne { fromb(a != b) }
-              ge { fromb(a >= b) } gt { fromb(a > b) }
-            }
-          }
-          (const_int(a), const_int(b)) {
-            alt check op {
-              add { const_int(a + b) } subtract { const_int(a - b) }
-              mul { const_int(a * b) } div { const_int(a / b) }
-              rem { const_int(a % b) } and | bitand { const_int(a & b) }
-              or | bitor { const_int(a | b) } bitxor { const_int(a ^ b) }
-              lsl { const_int(a << b) } lsr { const_int(a >> b) }
-              asr { const_int(a >>> b) }
-              eq { fromb(a == b) } lt { fromb(a < b) }
-              le { fromb(a <= b) } ne { fromb(a != b) }
-              ge { fromb(a >= b) } gt { fromb(a > b) }
-            }
-
-          }
-          (const_uint(a), const_uint(b)) {
-            alt check op {
-              add { const_uint(a + b) } subtract { const_uint(a - b) }
-              mul { const_uint(a * b) } div { const_uint(a / b) }
-              rem { const_uint(a % b) } and | bitand { const_uint(a & b) }
-              or | bitor { const_uint(a | b) } bitxor { const_uint(a ^ b) }
-              lsl { const_int((a << b) as i64) }
-              lsr { const_int((a >> b) as i64) }
-              asr { const_int((a >>> b) as i64) }
-              eq { fromb(a == b) } lt { fromb(a < b) }
-              le { fromb(a <= b) } ne { fromb(a != b) }
-              ge { fromb(a >= b) } gt { fromb(a > b) }
-            }
-          }
-        }
-      }
-      expr_cast(base, _) {
-        let ety = ty::expr_ty(tcx, e);
-        let base = eval_const_expr(tcx, base);
-        alt check ty::get(ety).struct {
-          ty::ty_float(_) {
-            alt check base {
-              const_uint(u) { const_float(u as f64) }
-              const_int(i) { const_float(i as f64) }
-              const_float(_) { base }
-            }
-          }
-          ty::ty_uint(_) {
-            alt check base {
-              const_uint(_) { base }
-              const_int(i) { const_uint(i as u64) }
-              const_float(f) { const_uint(f as u64) }
-            }
-          }
-          ty::ty_int(_) | ty::ty_bool {
-            alt check base {
-              const_uint(u) { const_int(u as i64) }
-              const_int(_) { base }
-              const_float(f) { const_int(f as i64) }
-            }
-          }
-        }
-      }
-      expr_lit(lit) { lit_to_const(lit) }
-    }
-}
-
-fn lit_to_const(lit: @lit) -> const_val {
-    alt lit.node {
-      lit_str(s) { const_str(s) }
-      lit_int(n, _) { const_int(n) }
-      lit_uint(n, _) { const_uint(n) }
-      lit_float(n, _) { const_float(option::get(float::from_str(n))) }
-      lit_nil { const_int(0i64) }
-      lit_bool(b) { const_int(b as i64) }
-    }
-}
-
-fn compare_const_vals(a: const_val, b: const_val) -> int {
-  alt (a, b) {
-    (const_int(a), const_int(b)) {
-        if a == b {
-            0
-        } else if a < b {
-            -1
-        } else {
-            1
-        }
-    }
-    (const_uint(a), const_uint(b)) {
-        if a == b {
-            0
-        } else if a < b {
-            -1
-        } else {
-            1
-        }
-    }
-    (const_float(a), const_float(b)) {
-        if a == b {
-            0
-        } else if a < b {
-            -1
-        } else {
-            1
-        }
-    }
-    (const_str(a), const_str(b)) {
-        if a == b {
-            0
-        } else if a < b {
-            -1
-        } else {
-            1
-        }
-    }
-    _ {
-        fail "compare_const_vals: ill-typed comparison";
-    }
-  }
-}
-
-fn compare_lit_exprs(tcx: middle::ty::ctxt, a: @expr, b: @expr) -> int {
-  compare_const_vals(eval_const_expr(tcx, a), eval_const_expr(tcx, b))
-}
-
-fn lit_expr_eq(tcx: middle::ty::ctxt, a: @expr, b: @expr) -> bool {
-    compare_lit_exprs(tcx, a, b) == 0
-}
-
-fn lit_eq(a: @lit, b: @lit) -> bool {
-    compare_const_vals(lit_to_const(a), lit_to_const(b)) == 0
-}
-
 fn ident_to_path(s: span, i: ident) -> @path {
     @respan(s, {global: false, idents: [i], types: []})
 }