fix fieldtype vararg and union handling (JuliaLang#27059)

jrevels · web-flow · commit 1d53232f7de0 · 2018-05-11T16:37:37.000-04:00
* fix fieldtype vararg and union handling

* add tests
diff --git a/base/compiler/tfuncs.jl b/base/compiler/tfuncs.jl
@@ -620,8 +620,8 @@ function fieldtype_tfunc(@nospecialize(s0), @nospecialize(name))
     if s0 === Any || s0 === Type || DataType &#8849; s0 || UnionAll &#8849; s0
         return Type
     end
-    # fieldtype only accepts DataType and UnionAll, errors on `Module`
-    if isa(s0,Const) && (!(isa(s0.val,DataType) || isa(s0.val,UnionAll)) || s0.val === Module)
+    # fieldtype only accepts Types, errors on `Module`
+    if isa(s0, Const) && (!(isa(s0.val, DataType) || isa(s0.val, UnionAll) || isa(s0.val, Union)) || s0.val === Module)
         return Bottom
     end
     if s0 == Type{Module} || s0 == Type{Union{}} || isa(s0, Conditional)
@@ -631,12 +631,12 @@ function fieldtype_tfunc(@nospecialize(s0), @nospecialize(name))
     s = instanceof_tfunc(s0)[1]
     u = unwrap_unionall(s)
 
-    if isa(u,Union)
-        return tmerge(rewrap(fieldtype_tfunc(u.a, name),s),
-                      rewrap(fieldtype_tfunc(u.b, name),s))
+    if isa(u, Union)
+        return tmerge(rewrap(fieldtype_tfunc(u.a, name), s),
+                      rewrap(fieldtype_tfunc(u.b, name), s))
     end
 
-    if !isa(u,DataType) || u.abstract
+    if !isa(u, DataType) || u.abstract
         return Type
     end
     if u.name === _NAMEDTUPLE_NAME && !isconcretetype(u)
@@ -656,7 +656,7 @@ function fieldtype_tfunc(@nospecialize(s0), @nospecialize(name))
     end
 
     fld = name.val
-    if isa(fld,Symbol)
+    if isa(fld, Symbol)
         fld = fieldindex(u, fld, false)
     end
     if !isa(fld, Int)
@@ -672,7 +672,7 @@ function fieldtype_tfunc(@nospecialize(s0), @nospecialize(name))
     end
 
     exact = (isa(s0, Const) || isType(s0)) && !has_free_typevars(s)
-    ft = rewrap_unionall(ft,s)
+    ft = rewrap_unionall(ft, s)
     if exact
         return Const(ft)
     end
diff --git a/src/builtins.c b/src/builtins.c
@@ -791,9 +791,19 @@ static jl_value_t *get_fieldtype(jl_value_t *t, jl_value_t *f)
         JL_GC_POP();
         return u;
     }
+    if (jl_is_uniontype(t)) {
+        jl_value_t **u;
+        jl_value_t *r;
+        JL_GC_PUSHARGS(u, 2);
+        u[0] = get_fieldtype(((jl_uniontype_t*)t)->a, f);
+        u[1] = get_fieldtype(((jl_uniontype_t*)t)->b, f);
+        r = jl_type_union(u, 2);
+        JL_GC_POP();
+        return r;
+    }
+    if (!jl_is_datatype(t))
+        jl_type_error("fieldtype", (jl_value_t*)jl_datatype_type, t);
     jl_datatype_t *st = (jl_datatype_t*)t;
-    if (!jl_is_datatype(st))
-        jl_type_error("fieldtype", (jl_value_t*)jl_datatype_type, (jl_value_t*)st);
     int field_index;
     if (jl_is_long(f)) {
         field_index = jl_unbox_long(f) - 1;
diff --git a/src/codegen.cpp b/src/codegen.cpp
@@ -2809,8 +2809,7 @@ static bool emit_builtin_call(jl_codectx_t &ctx, jl_cgval_t *ret, jl_value_t *f,
         const jl_cgval_t &typ = argv[1];
         const jl_cgval_t &fld = argv[2];
         if ((jl_is_type_type(typ.typ) && jl_is_concrete_type(jl_tparam0(typ.typ))) ||
-                (typ.constant && jl_is_datatype(typ.constant)) ||
-                typ.typ == (jl_value_t*)jl_datatype_type) {
+                (typ.constant && jl_is_concrete_type(typ.constant))) {
             if (fld.typ == (jl_value_t*)jl_long_type) {
                 assert(typ.isboxed);
                 Value *tyv = boxed(ctx, typ);
diff --git a/test/compiler/compiler.jl b/test/compiler/compiler.jl
@@ -1562,3 +1562,13 @@ for stmt in typed_code
 end
 
 @test found_well_typed_getfield_call
+
+# 27059 fix fieldtype vararg and union handling
+
+f27059(::Type{T}) where T = i -> fieldtype(T, i)
+T27059 = Tuple{Float64,Vararg{Float32}}
+@test f27059(T27059)(2) === fieldtype(T27059, 2) === Float32
+@test f27059(Union{T27059,Tuple{Vararg{Symbol}}})(2) === Union{Float32,Symbol}
+@test fieldtype(Union{Tuple{Int,Symbol},Tuple{Float64,String}}, 1) === Union{Int,Float64}
+@test fieldtype(Union{Tuple{Int,Symbol},Tuple{Float64,String}}, 2) === Union{Symbol,String}
+@test fieldtype(Union{Tuple{T,Symbol},Tuple{S,String}} where {T<:Number,S<:T}, 1) === Union{S,T} where {T<:Number,S<:T}
