Group common printing code during constant pretty printing

[rust.git] / src / librustc / ty / print / pretty.rs

diff --git a/src/librustc/ty/print/pretty.rs b/src/librustc/ty/print/pretty.rs
index 085a0edc9861dffc85219ec05c008684938f4866..6514017a3e74dddbcb12044eeb00437017502d60 100644 (file)
--- a/src/librustc/ty/print/pretty.rs
+++ b/src/librustc/ty/print/pretty.rs
@@ -1,11 +1,12 @@
 use crate::hir;
-use crate::hir::def::Namespace;
+use crate::hir::def::{Namespace, Def};
 use crate::hir::map::{DefPathData, DisambiguatedDefPathData};
 use crate::hir::def_id::{CrateNum, DefId, CRATE_DEF_INDEX, LOCAL_CRATE};
 use crate::middle::cstore::{ExternCrate, ExternCrateSource};
 use crate::middle::region;
 use crate::ty::{self, DefIdTree, ParamConst, Ty, TyCtxt, TypeFoldable};
 use crate::ty::subst::{Kind, Subst, UnpackedKind};
+use crate::ty::layout::Size;
 use crate::mir::interpret::{ConstValue, sign_extend, Scalar};
 use syntax::ast;
 use rustc_apfloat::ieee::{Double, Single};
@@ -1536,55 +1537,95 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         p!(print_def_path(self.def_id, self.substs));
     }
 
-    ty::Const<'tcx> {
-        match (self.val, &self.ty.sty) {
-            | (ConstValue::Unevaluated(..), _)
-            | (ConstValue::Infer(..), _)
-            => p!(write("_: "), print(self.ty)),
-            (ConstValue::Param(ParamConst { name, .. }), _) => p!(write("{}", name)),
-            (ConstValue::Scalar(Scalar::Bits { bits: 0, .. }), ty::Bool) => p!(write("false")),
-            (ConstValue::Scalar(Scalar::Bits { bits: 1, .. }), ty::Bool) => p!(write("true")),
-            (ConstValue::Scalar(Scalar::Bits { bits, .. }), ty::Float(ast::FloatTy::F32)) =>
-                p!(write(
-                    "{}f32",
-                    Single::from_bits(bits)
-                )),
-            (ConstValue::Scalar(Scalar::Bits { bits, .. }), ty::Float(ast::FloatTy::F64)) =>
-                p!(write(
-                    "{}f64",
-                    Double::from_bits(bits)
-                )),
-            (ConstValue::Scalar(Scalar::Bits { bits, ..}), ty::Uint(ui)) =>
-                p!(write("{}{}", bits, ui)),
-            (ConstValue::Scalar(Scalar::Bits { bits, ..}), ty::Int(i)) => {
-                let ty = cx.tcx().lift_to_global(&self.ty).unwrap();
-                let size = cx.tcx().layout_of(ty::ParamEnv::empty().and(ty))
-                    .unwrap()
-                    .size;
-                p!(write("{}{}", sign_extend(bits, size) as i128, i))
-            },
-            (ConstValue::Scalar(Scalar::Bits { bits, ..}), ty::Char)
-                => p!(write("{}", ::std::char::from_u32(bits as u32).unwrap())),
-            (_, ty::FnDef(did, _)) => p!(write("{}", cx.tcx().def_path_str(*did))),
-            (
-                ConstValue::Slice(place, len),
-                ty::Ref(_, &ty::TyS { sty: ty::Str, .. }, _),
-            ) => {
-                let s = match (place, len) {
-                    (_, 0) => "",
-                    (Scalar::Ptr(ptr), len) => {
-                        let alloc = cx.tcx().alloc_map.lock().unwrap_memory(ptr.alloc_id);
-                        assert_eq!(len as usize as u64, len);
-                        let slice =
-                            &alloc.bytes[(ptr.offset.bytes() as usize)..][..(len as usize)];
-                        ::std::str::from_utf8(slice).expect("non utf8 str from miri")
-                    },
-                    _ => bug!("invalid slice: {:#?}", self),
-                };
-                p!(write("{:?}", s))
-            },
-            _ => p!(write("{:?} : ", self.val), print(self.ty)),
+    &'tcx ty::Const<'tcx> {
+        let u8 = cx.tcx().types.u8;
+        if let ty::FnDef(did, _) = self.ty.sty {
+            p!(write("{}", cx.tcx().def_path_str(did)));
+            return Ok(cx);
+        }
+        if let ConstValue::Unevaluated(did, substs) = self.val {
+            match cx.tcx().describe_def(did) {
+                | Some(Def::Static(_, _))
+                | Some(Def::Const(_, false))
+                | Some(Def::AssociatedConst(_)) => p!(write("{}", cx.tcx().def_path_str(did))),
+                _ => p!(write("_")),
+            }
+            return Ok(cx);
+        }
+        if let ConstValue::Infer(..) = self.val {
+            p!(write("_: "), print(self.ty));
+            return Ok(cx);
+        }
+        if let ConstValue::Param(ParamConst { name, .. }) = self.val {
+            p!(write("{}", name));
+            return Ok(cx);
+        }
+        if let ConstValue::Scalar(Scalar::Bits { bits, .. }) = self.val {
+            match self.ty.sty {
+                ty::Bool => {
+                    p!(write("{}", if bits == 0 { "false" } else { "true" }));
+                    return Ok(cx);
+                },
+                ty::Float(ast::FloatTy::F32) => {
+                    p!(write("{}f32", Single::from_bits(bits)));
+                    return Ok(cx);
+                },
+                ty::Float(ast::FloatTy::F64) => {
+                    p!(write("{}f64", Double::from_bits(bits)));
+                    return Ok(cx);
+                },
+                ty::Uint(ui) => {
+                    p!(write("{}{}", bits, ui));
+                    return Ok(cx);
+                },
+                ty::Int(i) =>{
+                    let ty = cx.tcx().lift_to_global(&self.ty).unwrap();
+                    let size = cx.tcx().layout_of(ty::ParamEnv::empty().and(ty))
+                        .unwrap()
+                        .size;
+                    p!(write("{}{}", sign_extend(bits, size) as i128, i));
+                    return Ok(cx);
+                },
+                ty::Char => {
+                    p!(write("{:?}", ::std::char::from_u32(bits as u32).unwrap()));
+                    return Ok(cx);
+                }
+                _ => {},
+            }
+        }
+        if let ty::Ref(_, ref_ty, _) = self.ty.sty {
+            let byte_str = match (self.val, &ref_ty.sty) {
+                (ConstValue::Scalar(Scalar::Ptr(ptr)), ty::Array(t, n)) if *t == u8 => {
+                    let n = n.unwrap_usize(cx.tcx());
+                    Some(cx.tcx()
+                        .alloc_map.lock()
+                        .unwrap_memory(ptr.alloc_id)
+                        .get_bytes(&cx.tcx(), ptr, Size::from_bytes(n)).unwrap())
+                },
+                (ConstValue::Slice { data, start, end }, ty::Slice(t)) if *t == u8 => {
+                    Some(&data.bytes[start..end])
+                },
+                (ConstValue::Slice { data, start, end }, ty::Str) => {
+                    let slice = &data.bytes[start..end];
+                    let s = ::std::str::from_utf8(slice)
+                        .expect("non utf8 str from miri");
+                    p!(write("{:?}", s));
+                    return Ok(cx);
+                },
+                _ => None,
+            };
+            if let Some(byte_str) = byte_str {
+                p!(write("b\""));
+                for &c in byte_str {
+                    for e in std::ascii::escape_default(c) {
+                        p!(write("{}", e as char));
+                    }
+                }
+                p!(write("\""));
+                return Ok(cx);
+            }
         }
+        p!(write("{:?} : ", self.val), print(self.ty));
     }
 
     ty::ParamTy {