If the LTO threads == 0 clang will default to the same argument we
manually pass, which meant we dropped support for admittedly ancient
versions of clang that didn't yet add that option.
Drop the extraneous argument, and add a specific error condition when
too old versions of clang are detected.
Fixes#9569
-Oz is the appropriate flag to use when you want to produce the smallest
possible binary, and is one would expect when setting optimization to s
or using the minsize build type.
* compilers: improve docstring to `get_compiler_check_args()`
There was an incomplete list, which wasn't useful as it now takes an
enum anyway. Also add a new entry to the list of reasons to use this
function.
* clang: Add -Werror=implicit-function-declarations to check_args
Unlike GCC, clang warns but doesn't error when an implicit function
declaration happens. This means in checks like
`compiler.has_header_symbol('string.h', 'strlcat')` (on Linux, at least)
that GCC will fail, as there is no such function; clang will emit a
warning, but since it exists with a 0 status Meson interprets that as
success. To fix this, add `-Werror=implicit-function-declarations` to
clang's check arguments.
There seems to be something specific about functions that _may_ exist in
a header on a given system, as `cc.has_header_symbol('string.h',
'foobar')` will return false with clang, but `strlcat` will return true,
even though it's not defined. It is however, defined in some OSes, like
Solaris and the BSDs.
Fixes#9140
We have a lot of these. Some of them are harmless, if unidiomatic, such
as `if (condition)`, others are potentially dangerous `assert(...)`, as
`assert(condtion)` works as expected, but `assert(condition, message)`
will result in an assertion that never triggers, as what you're actually
asserting is `bool(tuple[2])`, which will always be true.
When mutable items are stored in an lru cache, changing the returned
items changes the cached items as well. Therefore we want to ensure that
we're not mutating them. Using the ImmutableListProtocol allows mypy to
find mutations and reject them. This doesn't solve the problem of
mutable values inside the values, so you could have to do things like:
```python
ImmutableListProtocol[ImmutableListProtocol[str]]
```
or equally hacky. It can also be used for input types and acts a bit
like C's const:
```python
def foo(arg: ImmutableListProtocol[str]) -> T.List[str]:
arg[1] = 'foo' # works while running, but mypy errors
```
* Allow address sanitizer for Visual Studio 2019 version 16.9
Address Sanitizer was first supported with the current syntax in Visual
Studio 16.9.0 (cl version 19.28.29910).
* VS: Convert /fsanitize=address to project file setting
This gets rid of compile warnings, and simplifies the code.
Note that `work_dir` in sanity_check_impl was incorrect,
it was used both to prepend to file names and as cwd=work_dir
argument to Popen. This is fixed here.
Closes gh-7344
Dependencies is already a large and complicated package without adding
programs to the list. This also allows us to untangle a bit of spaghetti
that we have.
All changes were created by running
"pyupgrade --py3-only --keep-percent-format"
and committing the results. I have not touched string formatting for
now.
- use set literals
- simplify .format() parameter naming
- remove __future__
- remove default "r" mode for open()
- use OSError rather than compatibility aliases
- remove stray parentheses in function(generator) scopes
Clang has a hand `-Wunused-command-line-argument` switch, which when
turned to an error, gets very grump about `-flto-jobs=0` being set in
the compiler arguments (although `-flto=` belongs there). We'll refactor
a bit to put that only in the link arguments.
GCC doesn't have this probably because, a) it doesn't have an equivalent
warning, and b) it uses `-flto=<$numthreads.
Fixes: #8347