Commit graph

7 commits

Author SHA1 Message Date
Andreas Kling
0255c8d976 Only apply auto-naming of function expressions based on syntax
The auto naming of function expressions is a purely syntactic
decision, so shouldn't be decided based on the dynamic type of
an assignment. This moves the decision making into the parser.

One icky hack is that we add a field to FunctionExpression to
indicate whether we can autoname. The real solution is to actually
generate a CompoundExpression node so that the parser can make
the correct decision, however this would have a potentially
significant run time cost.

This does not correct the behaviour for class expressions.

Patch from Anonymous.
2021-03-22 12:44:07 +01:00
Andreas Kling
c8382c32e9 LibJS: Split Value::Type::Number into Int32 and Double
We now store 32-bit integers as 32-bit integers directly which avoids
having to convert them from doubles when they're only used as 32-bit
integers anyway. :^)

This patch feels a bit incomplete and there's a lot of opportunities
to take advantage of this information. We'll have to find and exploit
them eventually.
2021-03-21 21:39:39 +01:00
Linus Groh
47645fc976 LibJS: Ensure SequenceExpression has two or more expressions
Just a sanity check, as we should be able to make this assumption
elsewhere - this way we can catch silly mistakes early.
2021-03-16 22:12:56 +01:00
Linus Groh
c499239137 LibJS: Implement non-value-producing statements properly
For various statements the spec states:

    Return NormalCompletion(empty).

In those cases we have been returning undefined so far, which is
incorrect.

In other cases it states:

    Return Completion(UpdateEmpty(stmtCompletion, undefined)).

Which essentially means a statement is evaluated and its completion
value returned if non-empty, and undefined otherwise.

While not actually noticeable in normal scripts as the VM's "last value"
can't be accessed from JS code directly (with the exception of eval(),
see below), it provided an inconsistent experience in the REPL:

    > if (true) 42;
    42
    > if (true) { 42; }
    undefined

This also fixes the case where eval() would return undefined if the last
executed statement is not a value-producing one:

    eval("1;;;;;")
    eval("1;{}")
    eval("1;var a;")

As a consequence of the changes outlined above, these now all correctly
return 1.

See https://tc39.es/ecma262/#sec-block-runtime-semantics-evaluation,
"NOTE 2".

Fixes #3609.
2021-03-16 10:08:07 +01:00
Andreas Kling
5d180d1f99 Everywhere: Rename ASSERT => VERIFY
(...and ASSERT_NOT_REACHED => VERIFY_NOT_REACHED)

Since all of these checks are done in release builds as well,
let's rename them to VERIFY to prevent confusion, as everyone is
used to assertions being compiled out in release.

We can introduce a new ASSERT macro that is specifically for debug
checks, but I'm doing this wholesale conversion first since we've
accumulated thousands of these already, and it's not immediately
obvious which ones are suitable for ASSERT.
2021-02-23 20:56:54 +01:00
Andreas Kling
4da913bfab LibJS: Replace ASTNode::class_name() with RTTI
This is only used for debugging anyway, so performance doesn't matter
too much.
2021-01-17 14:36:53 +01:00
Andreas Kling
13d7c09125 Libraries: Move to Userland/Libraries/ 2021-01-12 12:17:46 +01:00
Renamed from Libraries/LibJS/AST.h (Browse further)