Instead of only parsing a primary expression, we should also allow
member expressions, call expressions, and tagged template literals (and
optional chains, which we don't have yet).
In the spec, all of this is covered by `LeftHandSideExpression`
(https://tc39.es/ecma262/#prod-LeftHandSideExpression).
This requires variables that should be exported to the script host
or to other scripts to be declared as var (such as in test-common.js),
since lexically-scoped variables won't be visible.
The parser doesn't always track lexical scopes correctly, so let's not
rely on that for direct argument loading.
This reverts the LoadArguments bytecode instruction as well. We can
bring these things back when the parser can reliably tell us that
a given Identifier is indeed a function argument.
To better follow the spec, we need to distinguish between the current
execution context's lexical environment and variable environment.
This patch moves us to having two record pointers, although both of
them point at the same environment records for now.
This patch makes the following name changes:
- ScopeObject => EnvironmentRecord
- LexicalEnvironment => DeclarativeEnvironmentRecord
- WithScope => ObjectEnvironmentRecord
From the specification:
It is a Syntax Error if StringValue of IdentifierName is the same
String value as the StringValue of any ReservedWord except for yield
or await.
It is a Syntax Error if this phrase is contained in strict mode code
and the StringValue of IdentifierName is: "implements", "interface",
"let", "package", "private", "protected", "public", "static", or
"yield".
This commit implements parsing for `yield *expr`, and the multiple
ways something can or can't be parsed like that.
Also makes yield-from a TODO in the bytecode generator.
Behold, the glory of javascript syntax:
```js
// 'yield' = expression in generators.
function* foo() {
yield
*bar; // <- Syntax error here, expression can't start with *
}
// 'yield' = identifier anywhere else.
function foo() {
yield
*bar; // Perfectly fine, this is just `yield * bar`
}
```
This patch adds an "argument index" field to Identifier AST nodes.
If the Identifier refers to a function parameter in the currently
open function scope, we stash the index of the parameter here.
This will allow us to implement much faster direct access to function
argument variables.
The property name in an object literal can either be a literal or a
computed name, in which case any AssignmentExpression can be used, we
now only parse AssignmentExpression instead of the previous incorrect
behaviour which allowed any Expression (Specifically, comma
expressions).
The addition of an is_generator parameter broke this, as is_strict was
being passed in, causing an assertion.
This is being addressed by changing it to an enum in #7981, but in the
meantime let's just fix these two cases.
Checking for this (and get()'ing it) is always invalid, so let's just
disallow it.
This also finds two bugs where the code is checking for types that can
never actually be in the variant (which was actually a refactor
artifact).
This patch changes the validation of RegExp flags (checking for
invalid and duplicate values) from a SyntaxError at runtime to a
SyntaxError at parse time - it's not something that's supposed to be
catchable.
As a nice side effect, this simplifies the RegExpObject constructor a
bit, as it can no longer throw an exception and doesn't have to validate
the flags itself.
