This updates the following set of console builtins in V8 to match the
Console Standard (https://console.spec.whatwg.org) with respect to
(potentially side effecting) type conversions:
- console.debug
- console.error
- console.info
- console.log
- console.trace
- console.warn
- console.group
- console.groupCollapsed
- console.assert
The V8 implementation only performs the type conversions and updates
the arguments in-place with the results from the %String% constructor,
%parseInt%, or %parseFloat% invocations. The actual formatting is
still left completely to the debugger front-end.
To give a concrete example, the following code
```js
const msgFmt = {
toString() { return 'Message %i' }
};
console.log('LOG: %s`, msgFmt, 42);
```
sends the following parameters to the debugger front-end
```js
["LOG: %s", "Message %i", 42]
```
and it's then the job of the front-end to perform the actual string
substitutions.
It's also worth calling out that the console builtins are only
concerned with %s, %f, %d, and %i formatting specifiers, since
these are the only ones that trigger type conversions, and %o, %O,
and %c can only be implemented in a meaningful way at a higher
level.
Fixed: chromium:1277944
Bug: chromium:1282076
Doc: https://bit.ly/v8-proper-console-type-conversions
Spec: https://console.spec.whatwg.org
Change-Id: I0996680811aa96236bd0d879e4a11101629ef1a7
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3352118
Reviewed-by: Kim-Anh Tran <kimanh@chromium.org>
Auto-Submit: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78432}
console.context(name:string) method returns console instance, this console instance fully implements console interface (including fact that any method can be called without console as receiver).
Protocol.Runtime.consoleAPICalled notification contains additional context:string field:
- "anonymous#unique-id" for any method call on unnamed console context,
- "name#unique-id" for any method call on named console context.
console.count and console.timeEnd have context as a scope.
console.clear clear all messages regardless on what context instance it was called.
console calls is ~10% slower with this CL since we need to store and then fetch console_context_id and console_context_name from function object.
We recently (in April) made console calls twice faster so 10% doesn't sound critical and existing of console.log call in hot code is problem by itself.
R=pfeldman@chromium.org
Bug: chromium:728767
Change-Id: I5fc73216fb8b28bfe1e8c2c1b393ebfbe43cd02e
Reviewed-on: https://chromium-review.googlesource.com/522128
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45864}
