Syntax and validation for struct.new_desc

document/core/syntax/instructions.rst

@@ -265,6 +265,8 @@ while the latter performs a downcast and :ref:`traps <trap>` if the operand's ty
 
 .. _syntax-struct.new:
 .. _syntax-struct.new_default:
+.. _syntax-struct.new_desc:
+.. _syntax-struct.new_default_desc:
 .. _syntax-struct.get:
 .. _syntax-struct.get_s:
 .. _syntax-struct.get_u:
@@ -301,7 +303,8 @@ Instructions in this group are concerned with creating and accessing :ref:`refer
 
 $${syntax: {instr/struct instr/array instr/i31 instr/extern}}
 
-The instructions ${:STRUCT.NEW} and ${:STRUCT.NEW_DEFAULT} allocate a new :ref:`structure <syntax-structtype>`, initializing them either with operands or with default values.
+The instructions ${:STRUCT.NEW}, ${:STRUCT.NEW_DEFAULT} allocate a new :ref:`structure <syntax-structtype>`, initializing them either with operands or with default values.
+The instructions ${:STRUCT.NEW_DESC} and ${:STRUCT.NEW_DEFAULT_DESC} do the same, but additionally take the :ref:`descriptor <syntax-desctype>` operand necessary to allocate types with descriptors.
 The remaining instructions on structs access individual fields,
 allowing for different sign extension modes in the case of :ref:`packed <syntax-packtype>` storage types.
 

document/core/util/macros.def

@@ -342,8 +342,10 @@
 .. |rolldt| mathdef:: \xref{valid/conventions}{aux-roll-deftype}{\F{roll}}
 .. |unrolldt| mathdef:: \xref{valid/conventions}{aux-unroll-deftype}{\F{unroll}}
 .. |expanddt| mathdef:: \xref{valid/conventions}{aux-expand-deftype}{\F{expand}}
+.. |expanddttodesctype| mathdef:: \xref{valid/conventions}{aux-expand-deftype-to-desctype}{\F{expand}}
 .. |approxexpanddt| mathdef:: \mathrel{\xref{valid/conventions}{aux-expand-deftype}{\approx}}
 .. |approxexpandyy| mathdef:: \mathrel{\xref{valid/conventions}{aux-expand-typeuse}{\approx}}
+.. |approxexpanddttodesctype| mathdef:: \mathrel{\xref{valid/conventions}{aux-expand-deftype-to-desctype}{\approx}}
 .. |unrollht| mathdef:: \xref{appendix/properties}{aux-unroll-heaptype}{\F{unroll}}
 
 .. |unpack| mathdef:: \xref{syntax/types}{aux-unpack}{\F{unpack}}
@@ -551,6 +553,8 @@
 
 .. |STRUCTNEW| mathdef:: \xref{syntax/instructions}{syntax-instr-struct}{\K{struct{.}new}}
 .. |STRUCTNEWDEFAULT| mathdef:: \xref{syntax/instructions}{syntax-instr-struct}{\K{struct{.}new\_default}}
+.. |STRUCTNEWDESC| mathdef:: \xref{syntax/instructions}{syntax-instr-struct}{\K{struct{.}new\_desc}}
+.. |STRUCTNEWDEFAULTDESC| mathdef:: \xref{syntax/instructions}{syntax-instr-struct}{\K{struct{.}new\_default\_desc}}
 .. |STRUCTGET| mathdef:: \xref{syntax/instructions}{syntax-instr-struct}{\K{struct{.}get}}
 .. |STRUCTGETS| mathdef:: \xref{syntax/instructions}{syntax-instr-struct}{\K{struct{.}get\_s}}
 .. |STRUCTGETU| mathdef:: \xref{syntax/instructions}{syntax-instr-struct}{\K{struct{.}get\_u}}

document/core/valid/conventions.rst

@@ -138,6 +138,7 @@ Conventions
 .. _aux-roll-deftype:
 .. _aux-unroll-deftype:
 .. _aux-expand-deftype:
+.. _aux-expand-deftype-to-desctype:
 .. _aux-expand-typeuse:
 
 Rolling and Unrolling
@@ -169,6 +170,10 @@ $${rule: Expand {Expand_use/*}}
 $${relation-ignore: Expand Expand_use}
 $${definition-ignore: expanddt}
 
+We use the same notation to denote the expansion of a :ref:`defined type <syntax-deftype>` or :ref:`type use <syntax-typeuse>` to a :ref:`desctype <syntax-desctype>` as well.
+
+$${rule: ExpandDesc}
+
 
 .. index:: ! instruction type, value type, result type, instruction, local, local index
    pair: abstract syntax; instruction type

document/core/valid/instructions.rst

@@ -854,6 +854,26 @@ $${rule-prose: Instr_ok/struct.new_default}
 $${rule: Instr_ok/struct.new_default}
 
 
+.. _valid-struct.new_desc:
+
+:math:`\STRUCTNEWDESC~x`
+........................
+
+$${rule-prose: Instr_ok/struct.new_desc}
+
+$${rule: Instr_ok/struct.new_desc}
+
+
+.. _valid-struct.new_default_desc:
+
+:math:`\STRUCTNEWDEFAULTDESC~x`
+...............................
+
+$${rule-prose: Instr_ok/struct.new_default_desc}
+
+$${rule: Instr_ok/struct.new_default_desc}
+
+
 .. _valid-struct.get:
 .. _valid-struct.get_u:
 .. _valid-struct.get_s:
@@ -1421,6 +1441,7 @@ $${rule:
   {Instr_const/const Instr_const/vconst Instr_const/binop}
   {Instr_const/ref.null Instr_const/ref.i31 Instr_const/ref.func}
   {Instr_const/struct.new Instr_const/struct.new_default}
+  {Instr_const/struct.new_desc Instr_const/struct.new_default_desc}
   {Instr_const/array.new Instr_const/array.new_default Instr_const/array.new_fixed}
   {Instr_const/any.convert_extern Instr_const/extern.convert_any}
   {Instr_const/global.get}

specification/wasm-latest/1.2-syntax.types.spectec

@@ -474,7 +474,7 @@ def $rollrt(typeidx, rectype) : rectype  hint(show $roll_(%, %))   hint(macro "r
 def $unrollrt(rectype) : rectype         hint(show $unroll(%))     hint(macro "unrollrt")
 def $rolldt(typeidx, rectype) : deftype* hint(show $roll_(%)*#((%))) hint(macro "rolldt")
 def $unrolldt(deftype) : subtype         hint(show $unroll(%))     hint(macro "unrolldt")
-def $expanddt_to_desctype(deftype) : desctype  hint(show $expand_desc(%))
+def $expanddt_to_desctype(deftype) : desctype  hint(show $expand_desc(%))  hint(macro "expanddttodesctype")
 def $expanddt(deftype) : comptype        hint(show $expand(%))     hint(macro "expanddt")
 
 def $rollrt(x, rectype) = REC ($subst_subtype(subtype, ((_IDX $(x + i)))^(i<n), (REC i)^(i<n)))^n

specification/wasm-latest/1.3-syntax.instructions.spectec

@@ -322,6 +322,8 @@ syntax instr/i31 hint(desc "scalar reference instruction") = ...
 syntax instr/struct hint(desc "structure reference instruction") = ...
   | STRUCT.NEW typeidx
   | STRUCT.NEW_DEFAULT typeidx
+  | STRUCT.NEW_DESC typeidx
+  | STRUCT.NEW_DEFAULT_DESC typeidx
   | STRUCT.GET sx? typeidx u32      hint(show STRUCT.GET#_#% % %)
   | STRUCT.SET typeidx u32
   | ...

specification/wasm-latest/2.1-validation.types.spectec

@@ -77,6 +77,11 @@ rule Expand: deftype ~~ comptype   -- if $expanddt(deftype) = comptype
 rule Expand_use/deftype: deftype ~~_C comptype       -- Expand: deftype ~~ comptype
 rule Expand_use/typeidx: _IDX typeidx ~~_C comptype  -- Expand: C.TYPES[typeidx] ~~ comptype
 
+relation ExpandDesc: deftype ~~ desctype hint(macro "%expanddt_to_desctype") hint(tabular)
+  hint(prose "The :ref:`expansion <aux-expand-deftype-to-desctype>` of %1 is %2") ;; TODO(3, ?): avoid hardcoding reST
+
+rule ExpandDesc: deftype ~~ desctype  -- if $expanddt_to_desctype(deftype) = desctype
+
 
 ;; Type definitions
 

specification/wasm-latest/2.3-validation.instructions.spectec

@@ -251,11 +251,20 @@ rule Instr_ok/i31.get:
 
 rule Instr_ok/struct.new:
   C |- STRUCT.NEW x : $unpack(zt)* -> (REF (_IDX x))
-  -- Expand: C.TYPES[x] ~~ STRUCT (mut? zt)*
+  -- ExpandDesc: C.TYPES[x] ~~ describestype? eps STRUCT (mut? zt)*
 
 rule Instr_ok/struct.new_default:
   C |- STRUCT.NEW_DEFAULT x : eps -> (REF (_IDX x))
-  -- Expand: C.TYPES[x] ~~ STRUCT (mut? zt)*
+  -- ExpandDesc: C.TYPES[x] ~~ describestype? eps STRUCT (mut? zt)*
+  -- (Defaultable: |- $unpack(zt) DEFAULTABLE)*
+
+rule Instr_ok/struct.new_desc:
+  C |- STRUCT.NEW_DESC x : $unpack(zt)* (REF NULL (EXACT (_IDX y))) -> (REF (EXACT (_IDX x)))
+  -- ExpandDesc: C.TYPES[x] ~~ describestype? (DESCRIPTOR (_IDX y)) (STRUCT (mut? zt)*)
+
+rule Instr_ok/struct.new_default_desc:
+  C |- STRUCT.NEW_DEFAULT_DESC x : (REF NULL (EXACT (_IDX y))) -> (REF (EXACT (_IDX x)))
+  -- ExpandDesc: C.TYPES[x] ~~ describestype? (DESCRIPTOR (_IDX y)) (STRUCT (mut? zt)*)
   -- (Defaultable: |- $unpack(zt) DEFAULTABLE)*
 
 def $is_packtype(storagetype) : bool             hint(show %1 = $unpack(%1)) hint(prose "%1 is a packed type")
@@ -673,6 +682,12 @@ rule Instr_const/struct.new:
 rule Instr_const/struct.new_default:
   C |- (STRUCT.NEW_DEFAULT x) CONST
 
+rule Instr_const/struct.new_desc:
+  C |- (STRUCT.NEW_DESC x) CONST
+
+rule Instr_const/struct.new_default_desc:
+  C |- (STRUCT.NEW_DEFAULT_DESC x) CONST
+
 rule Instr_const/array.new:
   C |- (ARRAY.NEW x) CONST
 

spectec/src/backend-prose/gen.ml

@@ -32,7 +32,7 @@ let flatten_rec def =
 
 let is_validation_helper_relation def =
   match def.it with
-  | Ast.RelD (id, _, _, _) -> id.it = "Expand" || id.it = "Expand_use"
+  | Ast.RelD (id, _, _, _) -> id.it = "Expand" || id.it = "Expand_use" || id.it = "ExpandDesc"
   | _ -> false
 (* NOTE: Assume validation relation is `|-` *)
 let is_validation_relation def =