Added some information about 'j' and 'p' types and function signatures #22562
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sbc100
reviewed
Sep 11, 2024
| character within a signature string represents a type. The first character | ||
| represents the return type of a function, and remaining characters are for | ||
| parameter types. | ||
| When using ``addFunction`` on the LLVM Wasm backend, you need to provide |
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Can you remove on the LLVM Wasm backend here? there is no other backend anymore.
Instead how about When using ``addFunction`` with a JavaScript function, you need to...
| For example, if you add a function that takes an integer and does not return | ||
| anything, the signature is ``'vi'``. | ||
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| ``'j'`` must be used with the ``__i53abi`` decorator. It simplifies passing 64-bit numbers in JavaScript libraries. It cannot be used with ``addFunction``. Here is an example of a library function that sets the size of a file using a 64-bit value and returns |
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When j is used there are several ways in which the parameter value will be passed to JavaScript. By default the value will either be passed as a single bigint or a pair of JavaScript numbers (double) depending on whether the WASM_BIGINT settings is enabled. In addition, if you only require 53bits of precision you can add the __i53abi decorator, which will ignore the upper bits of the i64 and the value will be recieved as a single JavaScript number (double).
sbc100
approved these changes
Sep 11, 2024
| @@ -622,7 +622,7 @@ See `test_add_function in test/test_core.py`_ for an example. | |||
| You should build with ``-sALLOW_TABLE_GROWTH`` to allow new functions to be | |||
| added to the table. Otherwise by default the table has a fixed size. | |||
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| When using ``addFunction`` on the LLVM Wasm backend, you need to provide | |||
| When using ``addFunction`` with JavaScript function, you need to provide | |||
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with a JavaScript function?
| @@ -647,8 +647,7 @@ parameter types. | |||
| For example, if you add a function that takes an integer and does not return | |||
| anything, the signature is ``'vi'``. | |||
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| ``'j'`` must be used with the ``__i53abi`` decorator. It simplifies passing 64-bit numbers in JavaScript libraries. It cannot be used with ``addFunction``. Here is an example of a library function that sets the size of a file using a 64-bit value and returns | |||
| an integer error code: | |||
| When ``'j'`` is used there are several ways in which the parameter value will be passed to JavaScript. By default the value will either be passed as a single BigInt or a pair of JavaScript numbers (double) depending on whether the ``WASM_BIGINT`` settings is enabled. In addition, if you only require 53 bits of precision you can add the ``__i53abi`` decorator, which will ignore the upper bits and the value will be received as a single JavaScript number (double). It cannot be used with ``addFunction``. Here is an example of a library function that sets the size of a file using a 64-bit value passed as a 53 bit (double) and returns an integer error code: | |||
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Can you format this paragraph with line breaks at 80 columns?
sbc100
approved these changes
Sep 12, 2024
| @@ -647,7 +647,15 @@ parameter types. | |||
| For example, if you add a function that takes an integer and does not return | |||
| anything, the signature is ``'vi'``. | |||
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| When ``'j'`` is used there are several ways in which the parameter value will be passed to JavaScript. By default the value will either be passed as a single BigInt or a pair of JavaScript numbers (double) depending on whether the ``WASM_BIGINT`` settings is enabled. In addition, if you only require 53 bits of precision you can add the ``__i53abi`` decorator, which will ignore the upper bits and the value will be received as a single JavaScript number (double). It cannot be used with ``addFunction``. Here is an example of a library function that sets the size of a file using a 64-bit value passed as a 53 bit (double) and returns an integer error code: | |||
| When ``'j'`` is used there are several ways in which the parameter value will | |||
| be passed to JavaScript. By default the value will either be passed as a | |||
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Can you add a comma after "By default"
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This information needs to be reviewed by someone with deeper knowledge about function signatures, __i53abi, and WASM_BIGINT.