This new file is supposed to encapsulate all of the logic around
reacting to variable changes, as opposed to the environment core.
This is to help break up the env.cpp monolith.
This switches env_var_t to be an immutable value type, and stores its
contents via a shared_ptr. This eliminates string copying when fetching
env_var_t values.
For some reason, we have two places where a variable can be read-only:
- By key in env.cpp:is_read_only(), which is checked via set*
- By flag on the actual env_var_t, which is checked e.g. in
parse_execution
The latter didn't happen for non-electric variables like hostname,
because they used the default constructor, because they were
constructed via operator[] (or some such C++-iness).
This caused for-loops to crash on an assert if they used a
non-electric read-only var like $hostname or $SHLVL.
Instead, we explicitly set the flag.
We might want to remove one of the two read-only checks, or something?
Fixes#5548.
This requires threading environment_t through many places, such as completions
and history. We introduce null_environment_t for when the environment isn't
important.
This switches quoted expansion like "$foo" to use foo's delimiter instead of
space. The delimiter is space for normal variables and colonf or path variables.
Expansions like "$PATH" will now expand using ':'.
This commit begins to bake in a notion of path-style variables.
Prior to this fix, fish would export arrays as ASCII record separator
delimited, except for a whitelist (PATH, CDPATH, MANPATH). This is
surprising and awkward for other programs to deal with, and there's no way
to get similar behavior for other variables like GOPATH or LD_LIBRARY_PATH.
This commit does the following:
1. Exports all arrays as colon delimited strings, instead of RS.
2. Introduces a notion of "path variable." A path variable will be
"colon-delimited" which means it gets colon-separated in quoted expansion,
and automatically splits on colons. In this commit we only do the exporting
part.
Colons are not escaped in exporting; this is deliberate to support uses
like
`set -x PYTHONPATH "/foo:/bar"`
which ought to work (and already do, we don't want to make a compat break
here).
This switches fish to a "virtual" PWD, where it no longer uses getcwd to
discover its PWD but instead synthesizes it based on normalizing cd against
the $PWD variable.
Both pwd and $PWD contain the virtual path. pwd is taught about -P to
return the physical path, and -L the logical path (which is the default).
Fixes#3350
The previous commit caused the tests to fail since env_remove() was
returning a blanket `!0` when a variable couldn't be unset because it
didn't exist in the first place. This caused the wrong message to be
emitted since the code clashed with a return code for `env_set()`.
Added `ENV_NOT_FOUND` to signify that the variable requested unset
didn't exist in the first place, but _not_ printing the error message
currently so as not to break existing behavior before checking if this
is something we want.
The newly added `:` command is implemented as a function (to avoid
increasing complexity by making it a builtin), but it is saved to a path
that does not match its filename (since its name is somewhat of a
special character that might cause problems during installation).
Directly probing the `colon` function for autoload causes `:` to be
correctly loaded, so doing just that after function paths are loaded
upon startup.
This is a hack since the CPP code shouldn't really be aware of
individual functions, perhaps there is a better way of doing this.
* Hoist `for` loop control var to enclosing scope
It should be possible to reference the last value assigned to a `for`
loop control var when the loop terminates. This makes it easier to detect
if we broke out of the loop among other things. This change makes fish
`for` loops behave like most other shells.
Fixes#1935
* Remove redundant line
This eliminates the "missing" notion of env_var_t. Instead
env_get returns a maybe_t<env_var_t>, which forces callers to
handle the possibility that the variable is missing.
This commit backs out certain optimizations around setting environment
variables, and replaces them with move semantics. env_set accepts a
list, by value, permitting callers to use std::move to transfer
ownership.
Make setting fish vars more efficient by avoiding creating a
wcstring_list_t for the case where we're setting one value. For the case
where we're passing a list of values swap it with the list in the var
rather than copying it. This makes the benchmark in #4200 approximately
6% faster.
Internally fish should store vars as a vector of elements. The current
flat string representation is a holdover from when the code was written
in C.
Fixes#4200
Make the `env_var_t::missing_var()` object a singleton rather than a
dynamically constructed object. This requires some discipline in its use
since C++ doesn't directly support immutable objects. But it is slightly
more efficient and helps identify code that incorrectly mutates `env_var_t`
objects that should not be modified.
It's bugged me forever that the scope is the second arg to `env_get()`
but not `env_set()`. And since I'll be introducing some helper functions
that wrap `env_set()` now is a good time to change the order of its
arguments.
My previous change to eliminate `class var_entry_t` caused me to notice
that `env_get()` turned a set but empty var into a missing var. Which
is wrong. Fixing that brought to light several other pieces of code that
were wrong as a consequence of the aforementioned bug.
Another step to fixing issue #4200.
This is the first step to implementing issue #4200 is to stop subclassing
env_var_t from wcstring. Not too surprisingly doing this identified
several places that were incorrectly treating env_var_t and wcstring as
interchangeable types. I'm not talking about those places that passed
an env_var_t instance to a function that takes a wcstring. I'm talking
about doing things like assigning the former to the latter type, relying
on the implicit conversion, and thus losing information.
We also rename `env_get_string()` to `env_get()` for symmetry with
`env_set()` and to make it clear the function does not return a string.
This is the first step in implementing a better abstraction for handling
fish script vars in the C++ code. It implements a new function (with two
signatures) to provide a standard method for construct the flag string
representation of a fish script array.
Partial fix for #4200
There should be just one place that calls `setupterm()`. While refactoring
the code I also decided to not make initializing the curses subsystem a
fatal error. We now try two fallback terminal names ("ansi" and "dumb")
and if those can't be used we still end up with a usable shell.
Fixes#3850
I recently upgraded the software on my macOS server and was dismayed to
see that cppcheck reported a huge number of format string errors due to
mismatches between the format string and its arguments from calls to
`assert()`. It turns out they are due to the macOS header using `%lu`
for the line number which is obviously wrong since it is using the C
preprocessor `__LINE__` symbol which evaluates to a signed int.
I also noticed that the macOS implementation writes to stdout, rather
than stderr. It also uses `printf()` which can be a problem on some
platforms if the stream is already in wide mode which is the normal case
for fish.
So implement our own `assert()` implementation. This also eliminates
double-negative warnings that we get from some of our calls to
`assert()` on some platforms by oclint.
Also reimplement the `DIE()` macro in terms of our internal
implementation.
Rewrite `assert(0 && msg)` statements to `DIE(msg)` for clarity and to
eliminate oclint warnings about constant expressions.
Fixes#3276, albeit not in the fashion I originally envisioned.
This puts a hard upper bound of 10 MiB on the amount of data that read
will consume. This is to avoid having the shell consume an unreasonable
amount of memory, possibly causing the system to enter a OOM condition,
if the user does something non-sensical.
Fixes#3712
