auto merge of #8744 : jld/rust/discr64, r=nikomatsakis

This is in preparation for making discriminants not always be int (#1647), but it also makes compiles for a 64-bit target not behave differently — with respect to how many bits of discriminants are preserved — depending on the build host's word size, which is a nice property to have.

We may want to standardize how to abbreviate "discriminant" in a followup change.

Author: bors

src/librustc/metadata/decoder.rs

@@ -26,7 +26,7 @@ use middle::astencode::vtable_decoder_helpers;
 
 
 use std::hash::HashUtil;
-use std::uint;
+use std::u64;
 use std::io::WriterUtil;
 use std::io;
 use std::option;
@@ -207,9 +207,9 @@ fn each_reexport(d: ebml::Doc, f: &fn(ebml::Doc) -> bool) -> bool {
     reader::tagged_docs(d, tag_items_data_item_reexport, f)
 }
 
-fn variant_disr_val(d: ebml::Doc) -> Option<uint> {
+fn variant_disr_val(d: ebml::Doc) -> Option<ty::Disr> {
     do reader::maybe_get_doc(d, tag_disr_val).chain |val_doc| {
-        do reader::with_doc_data(val_doc) |data| { uint::parse_bytes(data, 10u) }
+        do reader::with_doc_data(val_doc) |data| { u64::parse_bytes(data, 10u) }
     }
 }
 

src/librustc/metadata/encoder.rs

@@ -292,7 +292,7 @@ fn encode_symbol(ecx: &EncodeContext,
 
 fn encode_disr_val(_: &EncodeContext,
                    ebml_w: &mut writer::Encoder,
-                   disr_val: uint) {
+                   disr_val: ty::Disr) {
     ebml_w.start_tag(tag_disr_val);
     let s = disr_val.to_str();
     ebml_w.writer.write(s.as_bytes());

src/librustc/middle/trans/_match.rs

@@ -245,7 +245,7 @@ pub enum VecLenOpt {
 // range)
 enum Opt {
     lit(Lit),
-    var(/* disr val */ uint, @adt::Repr),
+    var(ty::Disr, @adt::Repr),
     range(@ast::expr, @ast::expr),
     vec_len(/* length */ uint, VecLenOpt, /*range of matches*/(uint, uint))
 }
@@ -992,7 +992,7 @@ struct ExtractedBlock {
 
 fn extract_variant_args(bcx: @mut Block,
                             repr: &adt::Repr,
-                            disr_val: uint,
+                            disr_val: ty::Disr,
                             val: ValueRef)
     -> ExtractedBlock {
     let _icx = push_ctxt("match::extract_variant_args");

src/librustc/middle/trans/adt.rs

@@ -55,6 +55,7 @@ use middle::trans::common::*;
 use middle::trans::machine;
 use middle::trans::type_of;
 use middle::ty;
+use middle::ty::Disr;
 use syntax::ast;
 use util::ppaux::ty_to_str;
 
@@ -64,7 +65,7 @@ use middle::trans::type_::Type;
 /// Representations.
 pub enum Repr {
     /// C-like enums; basically an int.
-    CEnum(uint, uint), // discriminant range
+    CEnum(Disr, Disr), // discriminant range
     /**
      * Single-case variants, and structs/tuples/records.
      *
@@ -89,7 +90,7 @@ pub enum Repr {
      * is represented such that `None` is a null pointer and `Some` is the
      * identity function.
      */
-    NullablePointer{ nonnull: Struct, nndiscr: uint, ptrfield: uint,
+    NullablePointer{ nonnull: Struct, nndiscr: Disr, ptrfield: uint,
                      nullfields: ~[ty::t] }
 }
 
@@ -140,7 +141,7 @@ fn represent_type_uncached(cx: &mut CrateContext, t: ty::t) -> Repr {
             return Univariant(mk_struct(cx, ftys, packed), dtor)
         }
         ty::ty_enum(def_id, ref substs) => {
-            struct Case { discr: uint, tys: ~[ty::t] };
+            struct Case { discr: Disr, tys: ~[ty::t] };
             impl Case {
                 fn is_zerolen(&self, cx: &mut CrateContext) -> bool {
                     mk_struct(cx, self.tys, false).size == 0
@@ -177,7 +178,7 @@ fn represent_type_uncached(cx: &mut CrateContext, t: ty::t) -> Repr {
             // Since there's at least one
             // non-empty body, explicit discriminants should have
             // been rejected by a checker before this point.
-            if !cases.iter().enumerate().all(|(i,c)| c.discr == i) {
+            if !cases.iter().enumerate().all(|(i,c)| c.discr == (i as Disr)) {
                 cx.sess.bug(fmt!("non-C-like enum %s with specified \
                                   discriminants",
                                  ty::item_path_str(cx.tcx, def_id)))
@@ -305,16 +306,16 @@ pub fn trans_get_discr(bcx: @mut Block, r: &Repr, scrutinee: ValueRef)
     -> ValueRef {
     match *r {
         CEnum(min, max) => load_discr(bcx, scrutinee, min, max),
-        Univariant(*) => C_uint(bcx.ccx(), 0),
-        General(ref cases) => load_discr(bcx, scrutinee, 0, cases.len() - 1),
+        Univariant(*) => C_disr(bcx.ccx(), 0),
+        General(ref cases) => load_discr(bcx, scrutinee, 0, (cases.len() - 1) as Disr),
         NullablePointer{ nonnull: ref nonnull, nndiscr, ptrfield, _ } => {
             ZExt(bcx, nullable_bitdiscr(bcx, nonnull, nndiscr, ptrfield, scrutinee),
                  Type::enum_discrim(bcx.ccx()))
         }
     }
 }
 
-fn nullable_bitdiscr(bcx: @mut Block, nonnull: &Struct, nndiscr: uint, ptrfield: uint,
+fn nullable_bitdiscr(bcx: @mut Block, nonnull: &Struct, nndiscr: Disr, ptrfield: uint,
                      scrutinee: ValueRef) -> ValueRef {
     let cmp = if nndiscr == 0 { IntEQ } else { IntNE };
     let llptr = Load(bcx, GEPi(bcx, scrutinee, [0, ptrfield]));
@@ -323,7 +324,7 @@ fn nullable_bitdiscr(bcx: @mut Block, nonnull: &Struct, nndiscr: uint, ptrfield:
 }
 
 /// Helper for cases where the discriminant is simply loaded.
-fn load_discr(bcx: @mut Block, scrutinee: ValueRef, min: uint, max: uint)
+fn load_discr(bcx: @mut Block, scrutinee: ValueRef, min: Disr, max: Disr)
     -> ValueRef {
     let ptr = GEPi(bcx, scrutinee, [0, 0]);
     if max + 1 == min {
@@ -347,16 +348,16 @@ fn load_discr(bcx: @mut Block, scrutinee: ValueRef, min: uint, max: uint)
  *
  * This should ideally be less tightly tied to `_match`.
  */
-pub fn trans_case(bcx: @mut Block, r: &Repr, discr: uint) -> _match::opt_result {
+pub fn trans_case(bcx: @mut Block, r: &Repr, discr: Disr) -> _match::opt_result {
     match *r {
         CEnum(*) => {
-            _match::single_result(rslt(bcx, C_uint(bcx.ccx(), discr)))
+            _match::single_result(rslt(bcx, C_disr(bcx.ccx(), discr)))
         }
         Univariant(*) => {
             bcx.ccx().sess.bug("no cases for univariants or structs")
         }
         General(*) => {
-            _match::single_result(rslt(bcx, C_uint(bcx.ccx(), discr)))
+            _match::single_result(rslt(bcx, C_disr(bcx.ccx(), discr)))
         }
         NullablePointer{ _ } => {
             assert!(discr == 0 || discr == 1);
@@ -370,11 +371,11 @@ pub fn trans_case(bcx: @mut Block, r: &Repr, discr: uint) -> _match::opt_result
  * representation.  The fields, if any, should then be initialized via
  * `trans_field_ptr`.
  */
-pub fn trans_start_init(bcx: @mut Block, r: &Repr, val: ValueRef, discr: uint) {
+pub fn trans_start_init(bcx: @mut Block, r: &Repr, val: ValueRef, discr: Disr) {
     match *r {
         CEnum(min, max) => {
             assert!(min <= discr && discr <= max);
-            Store(bcx, C_uint(bcx.ccx(), discr), GEPi(bcx, val, [0, 0]))
+            Store(bcx, C_disr(bcx.ccx(), discr), GEPi(bcx, val, [0, 0]))
         }
         Univariant(ref st, true) => {
             assert_eq!(discr, 0);
@@ -385,7 +386,7 @@ pub fn trans_start_init(bcx: @mut Block, r: &Repr, val: ValueRef, discr: uint) {
             assert_eq!(discr, 0);
         }
         General(*) => {
-            Store(bcx, C_uint(bcx.ccx(), discr), GEPi(bcx, val, [0, 0]))
+            Store(bcx, C_disr(bcx.ccx(), discr), GEPi(bcx, val, [0, 0]))
         }
         NullablePointer{ nonnull: ref nonnull, nndiscr, ptrfield, _ } => {
             if discr != nndiscr {
@@ -401,7 +402,7 @@ pub fn trans_start_init(bcx: @mut Block, r: &Repr, val: ValueRef, discr: uint) {
  * The number of fields in a given case; for use when obtaining this
  * information from the type or definition is less convenient.
  */
-pub fn num_args(r: &Repr, discr: uint) -> uint {
+pub fn num_args(r: &Repr, discr: Disr) -> uint {
     match *r {
         CEnum(*) => 0,
         Univariant(ref st, dtor) => {
@@ -416,7 +417,7 @@ pub fn num_args(r: &Repr, discr: uint) -> uint {
 }
 
 /// Access a field, at a point when the value's case is known.
-pub fn trans_field_ptr(bcx: @mut Block, r: &Repr, val: ValueRef, discr: uint,
+pub fn trans_field_ptr(bcx: @mut Block, r: &Repr, val: ValueRef, discr: Disr,
                        ix: uint) -> ValueRef {
     // Note: if this ever needs to generate conditionals (e.g., if we
     // decide to do some kind of cdr-coding-like non-unique repr
@@ -494,13 +495,13 @@ pub fn trans_drop_flag_ptr(bcx: @mut Block, r: &Repr, val: ValueRef) -> ValueRef
  * this could be changed in the future to avoid allocating unnecessary
  * space after values of shorter-than-maximum cases.
  */
-pub fn trans_const(ccx: &mut CrateContext, r: &Repr, discr: uint,
+pub fn trans_const(ccx: &mut CrateContext, r: &Repr, discr: Disr,
                    vals: &[ValueRef]) -> ValueRef {
     match *r {
         CEnum(min, max) => {
             assert_eq!(vals.len(), 0);
             assert!(min <= discr && discr <= max);
-            C_uint(ccx, discr)
+            C_disr(ccx, discr)
         }
         Univariant(ref st, _dro) => {
             assert_eq!(discr, 0);
@@ -509,7 +510,7 @@ pub fn trans_const(ccx: &mut CrateContext, r: &Repr, discr: uint,
         General(ref cases) => {
             let case = &cases[discr];
             let max_sz = cases.iter().map(|x| x.size).max().unwrap();
-            let discr_ty = C_uint(ccx, discr);
+            let discr_ty = C_disr(ccx, discr);
             let contents = build_const_struct(ccx, case,
                                               ~[discr_ty] + vals);
             C_struct(contents + &[padding(max_sz - case.size)])
@@ -581,15 +582,15 @@ fn roundup(x: u64, a: u64) -> u64 { ((x + (a - 1)) / a) * a }
 
 /// Get the discriminant of a constant value.  (Not currently used.)
 pub fn const_get_discrim(ccx: &mut CrateContext, r: &Repr, val: ValueRef)
-    -> uint {
+    -> Disr {
     match *r {
-        CEnum(*) => const_to_uint(val) as uint,
+        CEnum(*) => const_to_uint(val) as Disr,
         Univariant(*) => 0,
-        General(*) => const_to_uint(const_get_elt(ccx, val, [0])) as uint,
+        General(*) => const_to_uint(const_get_elt(ccx, val, [0])) as Disr,
         NullablePointer{ nndiscr, ptrfield, _ } => {
             if is_null(const_struct_field(ccx, val, ptrfield)) {
                 /* subtraction as uint is ok because nndiscr is either 0 or 1 */
-                (1 - nndiscr) as uint
+                (1 - nndiscr) as Disr
             } else {
                 nndiscr
             }
@@ -605,7 +606,7 @@ pub fn const_get_discrim(ccx: &mut CrateContext, r: &Repr, val: ValueRef)
  * raw LLVM-level structs and arrays.)
  */
 pub fn const_get_field(ccx: &mut CrateContext, r: &Repr, val: ValueRef,
-                       _discr: uint, ix: uint) -> ValueRef {
+                       _discr: Disr, ix: uint) -> ValueRef {
     match *r {
         CEnum(*) => ccx.sess.bug("element access in C-like enum const"),
         Univariant(*) => const_struct_field(ccx, val, ix),
@@ -644,3 +645,7 @@ pub fn is_newtypeish(r: &Repr) -> bool {
         _ => false
     }
 }
+
+fn C_disr(cx: &CrateContext, i: Disr) -> ValueRef {
+    return C_integral(cx.int_type, i, false);
+}

src/librustc/middle/trans/base.rs

@@ -2014,7 +2014,7 @@ pub fn trans_enum_variant(ccx: @mut CrateContext,
                           _enum_id: ast::NodeId,
                           variant: &ast::variant,
                           args: &[ast::variant_arg],
-                          disr: uint,
+                          disr: ty::Disr,
                           param_substs: Option<@param_substs>,
                           llfndecl: ValueRef) {
     let _icx = push_ctxt("trans_enum_variant");
@@ -2063,7 +2063,7 @@ pub fn trans_enum_variant_or_tuple_like_struct<A:IdAndTy>(
     ccx: @mut CrateContext,
     ctor_id: ast::NodeId,
     args: &[A],
-    disr: uint,
+    disr: ty::Disr,
     param_substs: Option<@param_substs>,
     llfndecl: ValueRef)
 {

src/librustc/middle/trans/consts.rs

@@ -453,7 +453,7 @@ fn const_expr_unadjusted(cx: @mut CrateContext, e: &ast::expr) -> ValueRef {
               (expr::cast_enum, expr::cast_float)  => {
                 let repr = adt::represent_type(cx, basety);
                 let discr = adt::const_get_discrim(cx, repr, v);
-                let iv = C_uint(cx, discr);
+                let iv = C_integral(cx.int_type, discr, false);
                 let ety_cast = expr::cast_type_kind(ety);
                 match ety_cast {
                     expr::cast_integral => {

src/librustc/middle/trans/expr.rs

@@ -1118,7 +1118,7 @@ pub fn trans_local_var(bcx: @mut Block, def: ast::def) -> Datum {
 pub fn with_field_tys<R>(tcx: ty::ctxt,
                          ty: ty::t,
                          node_id_opt: Option<ast::NodeId>,
-                         op: &fn(uint, (&[ty::field])) -> R) -> R {
+                         op: &fn(ty::Disr, (&[ty::field])) -> R) -> R {
     match ty::get(ty).sty {
         ty::ty_struct(did, ref substs) => {
             op(0, struct_fields(tcx, did, substs))
@@ -1235,7 +1235,7 @@ struct StructBaseInfo {
  * - `optbase` contains information on the base struct (if any) from
  * which remaining fields are copied; see comments on `StructBaseInfo`.
  */
-fn trans_adt(bcx: @mut Block, repr: &adt::Repr, discr: uint,
+fn trans_adt(bcx: @mut Block, repr: &adt::Repr, discr: ty::Disr,
              fields: &[(uint, @ast::expr)],
              optbase: Option<StructBaseInfo>,
              dest: Dest) -> @mut Block {

src/librustc/middle/trans/reflect.rs

@@ -317,7 +317,7 @@ impl Reflector {
                 for (i, v) in variants.iter().enumerate() {
                     let name = ccx.sess.str_of(v.name);
                     let variant_args = ~[this.c_uint(i),
-                                         this.c_uint(v.disr_val),
+                                         C_integral(self.bcx.ccx().int_type, v.disr_val, false),
                                          this.c_uint(v.args.len()),
                                          this.c_slice(name)];
                     do this.bracketed("enum_variant", variant_args) |this| {

src/librustc/middle/ty.rs

@@ -48,7 +48,9 @@ use syntax::abi::AbiSet;
 use syntax;
 use extra::enum_set::{EnumSet, CLike};
 
-pub static INITIAL_DISCRIMINANT_VALUE: uint = 0;
+pub type Disr = u64;
+
+pub static INITIAL_DISCRIMINANT_VALUE: Disr = 0;
 
 // Data types
 
@@ -3803,7 +3805,7 @@ pub struct VariantInfo {
     ctor_ty: t,
     name: ast::ident,
     id: ast::def_id,
-    disr_val: uint,
+    disr_val: Disr,
     vis: visibility
 }
 
@@ -3814,7 +3816,7 @@ impl VariantInfo {
     /// Does not do any caching of the value in the type context.
     pub fn from_ast_variant(cx: ctxt,
                             ast_variant: &ast::variant,
-                            discriminant: uint) -> VariantInfo {
+                            discriminant: Disr) -> VariantInfo {
 
         let ctor_ty = node_id_to_type(cx, ast_variant.node.id);
 
@@ -4008,7 +4010,7 @@ pub fn enum_variants(cx: ctxt, id: ast::def_id) -> @~[@VariantInfo] {
                     node: ast::item_enum(ref enum_definition, _),
                     _
                 }, _) => {
-            let mut last_discriminant: Option<uint> = None;
+            let mut last_discriminant: Option<Disr> = None;
             @enum_definition.variants.iter().map(|variant| {
 
                 let mut discriminant = match last_discriminant {
@@ -4018,8 +4020,8 @@ pub fn enum_variants(cx: ctxt, id: ast::def_id) -> @~[@VariantInfo] {
 
                 match variant.node.disr_expr {
                     Some(e) => match const_eval::eval_const_expr_partial(&cx, e) {
-                        Ok(const_eval::const_int(val)) => discriminant = val as uint,
-                        Ok(const_eval::const_uint(val)) => discriminant = val as uint,
+                        Ok(const_eval::const_int(val)) => discriminant = val as Disr,
+                        Ok(const_eval::const_uint(val)) => discriminant = val as Disr,
                         Ok(_) => {
                             cx.sess.span_err(e.span, "expected signed integer constant");
                         }

src/librustc/middle/typeck/check/mod.rs

@@ -83,7 +83,7 @@ use middle::pat_util;
 use middle::lint::unreachable_code;
 use middle::ty::{FnSig, VariantInfo};
 use middle::ty::{ty_param_bounds_and_ty, ty_param_substs_and_ty};
-use middle::ty::{substs, param_ty, ExprTyProvider};
+use middle::ty::{substs, param_ty, Disr, ExprTyProvider};
 use middle::ty;
 use middle::typeck::astconv::AstConv;
 use middle::typeck::astconv::{ast_region_to_region, ast_ty_to_ty};
@@ -3000,8 +3000,8 @@ pub fn check_enum_variants(ccx: @mut CrateCtxt,
 
         let rty = ty::node_id_to_type(ccx.tcx, id);
         let mut variants: ~[@ty::VariantInfo] = ~[];
-        let mut disr_vals: ~[uint] = ~[];
-        let mut prev_disr_val: Option<uint> = None;
+        let mut disr_vals: ~[ty::Disr] = ~[];
+        let mut prev_disr_val: Option<ty::Disr> = None;
 
         for v in vs.iter() {
 
@@ -3024,8 +3024,8 @@ pub fn check_enum_variants(ccx: @mut CrateCtxt,
                     // handle, so we may still get an internal compiler error
 
                     match const_eval::eval_const_expr_partial(&ccx.tcx, e) {
-                        Ok(const_eval::const_int(val)) => current_disr_val = val as uint,
-                        Ok(const_eval::const_uint(val)) => current_disr_val = val as uint,
+                        Ok(const_eval::const_int(val)) => current_disr_val = val as Disr,
+                        Ok(const_eval::const_uint(val)) => current_disr_val = val as Disr,
                         Ok(_) => {
                             ccx.tcx.sess.span_err(e.span, "expected signed integer constant");
                         }