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[spec] Remove obsolete notes and fix inaccurate side conditions #1311

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Merged
rossberg merged 3 commits into from
Apr 21, 2021
Merged

[spec] Remove obsolete notes and fix inaccurate side conditions #1311

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19e2a47
Remove obsolete notes
rossberg Apr 12, 2021
e12f981
Fix empty typeuses
rossberg Apr 12, 2021
1e28ee1
Adapt note
rossberg Apr 12, 2021
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6 changes: 0 additions & 6 deletions document/core/binary/instructions.rst
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Original file line number Diff line number Diff line change
Expand Up @@ -71,9 +71,6 @@ Control Instructions
Unlike any :ref:`other occurrence <binary-typeidx>`, the :ref:`type index <syntax-typeidx>` in a :ref:`block type <syntax-blocktype>` is encoded as a positive :ref:`signed integer <syntax-sint>`, so that its |SignedLEB128| bit pattern cannot collide with the encoding of :ref:`value types <binary-valtype>` or the special code :math:`\hex{40}`, which correspond to the LEB128 encoding of negative integers.
To avoid any loss in the range of allowed indices, it is treated as a 33 bit signed integer.

In future versions of WebAssembly, the zero byte occurring in the encoding
of the |CALLINDIRECT| instruction may be used to index additional tables.


.. index:: reference instruction
pair: binary format; instruction
Expand All @@ -95,9 +92,6 @@ Reference Instructions
\hex{D2}~~x{:}\Bfuncidx &\Rightarrow& \REFFUNC~x \\
\end{array}

.. note::
These opcode assignments are preliminary.


.. index:: parametric instruction, value type, polymorphism
pair: binary format; instruction
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8 changes: 4 additions & 4 deletions document/core/text/instructions.rst
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Expand Up @@ -71,7 +71,7 @@ However, the special case of a type use that is syntactically empty or consists
&
\begin{array}[t]{@{}lcll@{}}
(t{:}\Tresult)^? &\Rightarrow& t^? \\
x,I'{:}\Ttypeuse_I &\Rightarrow& x & (\iff I' = \{\}) \\
x,I'{:}\Ttypeuse_I &\Rightarrow& x & (\iff I' = \{\ILOCALS~(\epsilon)^\ast\}) \\
\end{array} \\
\production{block instruction} & \Tblockinstr_I &::=&
\text{block}~~I'{:}\Tlabel_I~~\X{bt}{:}\Tblocktype~~(\X{in}{:}\Tinstr_{I'})^\ast~~\text{end}~~\Tid^?
Expand All @@ -87,7 +87,7 @@ However, the special case of a type use that is syntactically empty or consists
\end{array}

.. note::
The side condition stating that the :ref:`identifier context <text-context>` :math:`I'` must be empty in the rule for |Ttypeuse| block types enforces that no identifier can be bound in any |Tparam| declaration for a block type.
The side condition stating that the :ref:`identifier context <text-context>` :math:`I'` must only contain unnamed entries in the rule for |Ttypeuse| block types enforces that no identifier can be bound in any |Tparam| declaration for a block type.


.. _text-nop:
Expand All @@ -113,11 +113,11 @@ All other control instruction are represented verbatim.
\text{return} &\Rightarrow& \RETURN \\ &&|&
\text{call}~~x{:}\Tfuncidx_I &\Rightarrow& \CALL~x \\ &&|&
\text{call\_indirect}~~x{:}\Ttableidx~~y,I'{:}\Ttypeuse_I &\Rightarrow& \CALLINDIRECT~x~y
& (\iff I' = \{\}) \\
& (\iff I' = \{\ILOCALS~(\epsilon)^\ast\}) \\
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@SpecLad SpecLad Apr 12, 2021

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I think the corresponding note should also be updated, because this is not an empty context.

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@rossberg rossberg Apr 12, 2021

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Good point, done.

\end{array}

.. note::
The side condition stating that the :ref:`identifier context <text-context>` :math:`I'` must be empty in the rule for |CALLINDIRECT| enforces that no identifier can be bound in any |Tparam| declaration appearing in the type annotation.
The side condition stating that the :ref:`identifier context <text-context>` :math:`I'` must only contain unnamed entries in the rule for |CALLINDIRECT| enforces that no identifier can be bound in any |Tparam| declaration appearing in the type annotation.


Abbreviations
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