Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Add suggested format for wasm frames in Error.stack #814

Closed
wants to merge 3 commits into from
Closed

Add suggested format for wasm frames in Error.stack #814

Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
19b8573
Add Error.stack SHOULD clause
Oct 3, 2016
85ea06d
Mention Names section for function names
Oct 4, 2016
de99b42
Change offset to best-effort
Oct 4, 2016
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
18 changes: 18 additions & 0 deletions JS.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -29,6 +29,24 @@ Because JavaScript exceptions can be handled, and JavaScript can continue to
call WebAssembly exports after a trap has been handled, traps do not, in
general, prevent future execution.

Even though the `stack` property of JS `Error` objects is not specified by
ES-262, implementations *should* include WebAssembly stack frames in
the generated callstacks. [User-defined sections](BinaryEncoding.md#high-level-structure)
may arbitrarily affect the displayed stack frames. However, by default, when
no relevant sections are present:
* The line number reported for a WebAssembly frame *should* be a best-effort
reconstruction of the offset of the frame's current trapping/calling
instruction within the module's originally-compiled binary.
* The column number reported for WebAssembly frames, if not omitted entirely,
*should* be 1.
* When a [Name section](BinaryEncoding.md#name-section) is present, the names
given to functions *should* be used in the callstack. Otherwise, for the `i`th
function in a module's [Code section](BinaryEncoding.md#code-section),
the name should be generated from the template string literal
`wasm-function[${i}]`.
* The filename *should* be that of the JS caller of the originating `Module`
constructor call.
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Not the .wasm file if there was one?

Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

The only JS APIs we have atm take an ArrayBuffer of bytes so I think this is the best we can do. With ES6 module integration, we could have the same URLs as JS <script>s. With Streams integration, if you WebAssembly.compile(stream), maybe we could use the URL that was fetched to produce stream.

Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Hmm, right.


## The `WebAssembly` object

The `WebAssembly` object is the initial value of the `WebAssembly` property of
Expand Down