The stack overflow tests are too slow without this.
This is because the tests are essentially quadratic: with 500 jobs, and
each job attempts to reap all jobs.
As the user is typing an argument, fish continually checks if the input is
the prefix of a valid file path. If yes, the input is underlined.
The same prefix-logic is used for all tokens on the command line, even for
"finished" tokens. This means we highlight any token that happens to be
a prefix of a valid file path. We actually want this to only apply to the
token that the user is currently typing.
Let's use the prefix-logic only for tokens adjacent to the cursor. This should
better match user expectations (and reduce IO traffic). I don't think this is
the perfect criteria but I don't know how else we can determine if a token is
"unfinished".
It seems to have originally been thought that the only possible way a stack
overflow could happen is via function calls, but there are other possibilities.
Issue #9302 reports how `eval` can be abused to recursively execute a string
substitution ad infinitum, triggering a stack overflow in fish.
This patch extends the stack overflow check to also check the current
`eval_level` against a new constant `FISH_MAX_EVAL_DEPTH`, currently set to a
conservative but hopefully still fair limit of 500. For future reference, with
the default stack size for the main/foreground thread of 8 MiB, we actually have
room for a stack depth around 2800, but that's only with extremely minimal state
stored in each stack frame.
I'm not entirely sure why we don't check `eval_depth` regardless of block type;
it can't be for performance reasons since it's just a simple integer comparison
- and a ridiculously easily one for the branch predictor handle, at that - but
maybe it's to try and support non-recursive nested execution blocks of greater
than `FISH_MAX_STACK_DEPTH`? But even without recursion, the stack can still
overflow so may be we should just bump the limit up some (to 500 like the new
`FISH_MAX_EVAL_DEPTH`?) and check it all the time?
Closes#9302.
This reverts commit 3d8f98c395.
In addition to the issues mentioned on the GitHub page for this commit,
it also broke the CentOS 7 build.
Note one can locally test the CentOS 7 build via:
./docker/docker_run_tests.sh ./docker/centos7.Dockerfile
Be more careful with sign extension issues stemming from the differences in how
an untyped literal is promoted to an integer vs how a typed (and signed) `char`
is promoted to an integer.
Also convert some `const[expr] static xxx` to `const[expr] xxx` where it makes
sense to let the compiler deduce on its own whether or not to allocate storage
for a constant variable rather than imposing our view that it should have STATIC
storage set aside for it.
A few call sites were not making use of the `XXX_LEN` definitions and were
calling `strlen(XXX)` - these have been updated to use `const_strlen(XXX)`
instead.
I'm not sure if any toolchains will have raise any issues with these changes...
CI will tell!
Previously, the search text is used to find out which part of the
updated command line should be highlighted during a history search. This
approach will cause the incorrect part to be highlighted when the line
contains multiple instances of the search text.
To address this, we have to find out exactly where to highlight, i.e.
the offset of the current token in the command line (0 if not a token
search) plus the offset of the search text in the match.
Seems like size_t is unnecessarily large as well, as elsewhere
in the code we are clamping down to uint32_t / source_offset_t.
This makes tok_t more like 16 bytes. More cleanup seems desirable,
this is not very well hamrnoized across our code base.
Currently, if a "return" is given outside of a function, we'd just
throw an error.
That always struck me as a bit weird, given that scripts can also
return a value.
So simply let "return" outside also exit the script, kinda like "exit"
does.
However, unlike "exit" it doesn't quit an interactive shell - it seems
weird to have "return" do that as well. It sets $status, so it can be
used to quickly set that, in case you want to test something.
This adds the ability to limit how many expansions are produced. For
example if $big contains 10 items, and is Cartesian-expanded as
$big$big$big$big... 10 times, we would naviely get 10^10 = 10 billion
results, which fish can't actually handle. Implement this in
completion_receiver_t, which now can return false to indicate an overflow.
The initial expansion limit 'k_default_expansion_limit' is set as 512k
items. There's no way for users to change this at present.
This is the first commit of a series intended to replace the existing
"parse tree" machinery. It adds a new abstract syntax tree and uses a more
normal recursive descent parser.
Initially there are no users of the new ast. The following commits will
replace parse_tree -> ast for all usages.
In particular, this allows `true && time true`, or `true; and time true`,
and both `time not true` as well as `not time true` (like bash).
time is valid only as job _prefix_, so `true | time true` could call
`/bin/time` (same in bash)
See discussion in #6442
Since #6287, bare variable assignments do not parse, which broke
the "Unsupported use of '='" error message.
This commit catches parse errors that occur on bare variable assignments.
When a statement node fails to parse, then we check if there is at least one
prefixing variable assignment. If so, we emit the old error message.
See also #6347
This adds initial support for statements with prefixed variable assignments.
Statments like this are supported:
a=1 b=$a echo $b # outputs 1
Just like in other shells, the left-hand side of each assignment must
be a valid variable identifier (no quoting/escaping). Array indexing
(PATH[1]=/bin ls $PATH) is *not* yet supported, but can be added fairly
easily.
The right hand side may be any valid string token, like a command
substitution, or a brace expansion.
Since `a=* foo` is equivalent to `begin set -lx a *; foo; end`,
the assignment, like `set`, uses nullglob behavior, e.g. below command
can safely be used to check if a directory is empty.
x=/nothing/{,.}* test (count $x) -eq 0
Generic file completion is done after the equal sign, so for example
pressing tab after something like `HOME=/` completes files in the
root directory
Subcommand completion works, so something like
`GIT_DIR=repo.git and command git ` correctly calls git completions
(but the git completion does not use the variable as of now).
The variable assignment is highlighted like an argument.
Closes#6048
We used to have a global notion of "is the shell interactive" but soon we
will want to have multiple independent execution threads, only some of
which may be interactive. Start tracking this data per-parser.
I did not realize builtins could safely call into the parser and inject
jobs during execution. This is much cleaner than hacking around the
required shape of a plain_statement.
While `eval` is still a function, this paves the way for changing that
in the future, and lets the proc/exec functions detect when an eval is
used to allow/disallow certain behaviors and optimizations.
Rather than having tokenizer_error as pointers to objects, switch it back
to just an error code value. This makes reasoning about it easier since
it's immutable values instead of mutable objects, and it avoids allocation
during startup.
This promotes "and" and "or" from a type of statement to "job
decorators," as a possible prefix on a job. The point is to rationalize
how they interact with && and ||.
In the new world 'and' and 'or' apply to a entire job conjunction, i.e.
they have "lower precedence." Example:
if [ $age -ge 0 ] && [ $age -le 18 ]
or [ $age -ge 75 ] && [ $age -le 100 ]
echo "Child or senior"
end
