-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
Both Clang and GCC support using multiple threads for preforming link
time optimizaions, and they can now be configured using the
`-Db_lto_threads` option.
Fixes#7820
This commit performs some cleanup for the msvc and clang-cl arguments.
* "Disable Debug" (`/Od`) is no longer manually specified for optimization levels {`0`,`g`} (it is already the default for MSVC).
* "Run Time Checking" (`/RTC1`) removed from `debug` buildtype by default
* Clang-CL `debug` buildtype arguments now match MSVC arguments
* There is now no difference between `buildtype` flags and `debug` + `optimization` flags
Compiler tests, such as checking for atomics support, could fail
when compiling to WebAssembly multithreaded targets because the
compiler tests got compiled to 'output.wasm'.
Using the '.wasm' suffix in recent versions of emscripten engages
STANDALONE_WASM mode, which disables features that require a JS
runtime like shared memory.
This created false negatives on support of those features when
building a library to be linked into an executable that is not
in STANDALONE_WASM mode.
Changing these to 'output.o' will continue to produce WebAssembly
object files, but they will no longer be configured for standalone
runtime mode.
The /ZI flag adds in "Edit and Continue" debug information, which will
cause massive slowdown. It is not a flag that we should be adding by
default to debug builds.
/Zi will still be added.