Previously we were simply ignoring the empty entry in '{,x}', making it
resolve to a list with a single element '(x)', this commit makes that
work as expected and resolve to '("" x)'.
When parse_expression looks at '$((', there are two ways it can end up
in parse_expression again, three consumed characters later. All these
ways fail, so what happened was that the parser tried all possible
combinations, hence taking potentially an exponential amount of time.
1. parse_evaluate swallows the '$(', a new invocation of
parse_expression swallows the other '(', and through
parse_list_expression we're at another parse_expression.
2. parse_evaluate swallows the '$(', but returns a SyntaxError.
parse_expression used to not recognize the error, and treated it as a
regular AST node, calling into read_concat, then a new invocation of
parse_expression swallows the other '(', and through
parse_list_expression we're at another parse_expression.
Fixes#10561.
Found by OSS Fuzz, long-standing issue
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=28113
Our existing implementation did not check the element type of the other
pointer in the constructors and move assignment operators. This meant
that some operations that would require explicit casting on raw pointers
were done implicitly, such as:
- downcasting a base class to a derived class (e.g. `Kernel::Inode` =>
`Kernel::ProcFSDirectoryInode` in Kernel/ProcFS.cpp),
- casting to an unrelated type (e.g. `Promise<bool>` => `Promise<Empty>`
in LibIMAP/Client.cpp)
This, of course, allows gross violations of the type system, and makes
the need to type-check less obvious before downcasting. Luckily, while
adding the `static_ptr_cast`s, only two truly incorrect usages were
found; in the other instances, our casts just needed to be made
explicit.
This is primarily to be able to remove the GenericLexer include out of
Format.h as well. A subsequent commit will add AK::Result to
GenericLexer, which will cause naming conflicts with other structures
named Result. This can be avoided (for now) by preventing nearly every
file in the system from implicitly including GenericLexer.
Other changes in this commit are to add the GenericLexer include to
files where it is missing.
Heredocs have a different parse end condition than double-quoted
strings. parse_doublequoted_string_inner would assume that a string
would always end in a double quote, so let's generalize it to
parse_string_inner and have it take a StringEndCondition enum which
specifies how the string terminates.
We had two functions for doing mostly the same thing. Combine both
of them into String::find() and use that everywhere.
Also add some tests to cover basic behavior.
Otherwise we would end up trying to parse the same heredoc entry, if it
contained a sequence terminated by a newline.
e.g. `<<-x\n$({` would attempt to read a heredoc entry after `x`, and
then after `{` while inside the first heredoc entry.
To make this work, we can simply empty the instance vector and keep the
state on the stack.
Issue found through oss-fuzz:
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=33852
Closes#4283.
Heredocs are implemented in a way that makes them feel more like a
string (and not a weird redirection, a la bash).
There are two tunables, whether the string is dedented (`<<-` vs `<<~`)
and whether it allows interpolation (quoted key vs not).
To the familiar people, this is how Ruby handles them, and I feel is the
most elegant heredoc syntax.
Unlike the oddjob that is bash, heredocs are treated exactly as normal
strings, and can be used _anywhere_ where a string can be used.
They are *required* to appear in the same order as used after a newline
is seen when parsing the sequence that the heredoc is used in.
For instance:
```sh
echo <<-doc1 <<-doc2 | blah blah
contents for doc1
doc1
contents for doc2
doc2
```
The typical nice errors are also implemented :^)
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
Now a variable may have an optional slice (only _one_ slice), which can
also use negative indices to index from the end.
This works on both lists and strings.
The contents of the slice have the same semantics as brace expansions.
For example:
```sh
$ x=(1 2 3 4 5 6)
$ echo $x[1..3] # select indices 1, 2, 3
2 3 4
$ echo $x[3,4,1,0] # select indices 3, 4, 1, 0 (in that order)
4 5 2 1
$ x="Well Hello Friends!"
$ echo $x[5..9]
Hello
```
This commit adds a few basic variable substitution operations:
- length
Find the length of a string or a list
- length_across
Find the lengths of things inside a list
- remove_{suffix,prefix}
Remove a suffix or a prefix from all the passed values
- regex_replace
Replace all matches of a given regex with a given template
- split
Split the given string with the given delimiter (or to its
code points if the delimiter is empty)
- concat_lists
concatenates any given lists into one
Closes#4316 (the ancient version of this same feature)
This is basically just for consistency, it's quite strange to see
multiple AK container types next to each other, some with and some
without the namespace prefix - we're 'using AK::Foo;' a lot and should
leverage that. :^)
(...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.
