In Linux when interacting with the virtual file system when writing
in invalid value to a file the OS will return errno 22 (INVAL).
Instead of triggering an unreachable, this change now returns a
newly introduced error.InvalidArgument.
In Linux when writing to various files in the virtual file system,
for example /sys/fs/cgroup, if you write an invalid value to a file
you'll get errno 16.
This change allows for these specific cases to be caught instead of
being lumped together in UnexpectedError.
Tested by: created a "hello world" C file and compiled with:
zig cc -v main.c -Wl,--sort-section=name -o main
... and verified the `--sort-section=name` is passed to ld.lld.
Refs https://github.com/zigchroot/zig-chroot/issues/1
This implements the `__wasm_call_ctors` symbol. This symbol is
automatically referenced by libc to initialize its constructors.
We first retrieve all constructors from each object file, and then
create a function body that calls each constructor based on its
priority. Constructors are not allowed to have any parameters, but are
allowed to have a return type. When a return type does exist, we simply
drop its value from the stack after calling the constructor to ensure
we pass the stack validator.
Using zig cc with CMake on Windows was failing during compiler
detection. -nostdinc was causing the crt not to be linked, and Coff/lld.zig
assumed that wWinMainCRTStartup would be present in this case.
-nostdlib did not prevent the default behaviour of linking libc++ when
zig c++ was used. This caused libc++ to be built when CMake ran
ABI detection using zig c++, which fails as libcxxabi cannot compile
under MSVC.
- Change the behaviour of COFF -nostdinc to set /entry to the function that the
default CRT method for the specified subsystem would have called.
- Fix -ENTRY being passed twice if it was specified explicitly and -nostdlib was present.
- Add support for /pdb, /version, /implib, and /subsystem as linker args (passed by CMake)
- Remove -Ddisable-zstd, no longer needed
- Add -Ddisable-libcpp for use when bootstrapping on msvc
- add support for passing through .def files to the linker,
required for building libLTO.dll in LLVM
- fixup libcpp linking conditionals
- add option to skip linking zstd for use in bootstrapping (when
building against an LLVM with LLVM_ENABLE_ZSTD=OFF)
In #1622, when targeting WebAsembly, the --allow-undefined flag
became unconditionally added to the linker.
This is not always desirable.
First, this is error prone. Code with references to unkown symbols
will link just fine, but then fail at run-time.
This behavior is inconsistent with all other targets.
For freestanding wasm applications, and applications that only use
WASI, undefined references are better reported at compile-time.
This behavior is also inconsistent with clang itself. Autoconf and
cmake scripts checking for function presence think that all tested
functions exist, but then resulting application cannot run.
For example, this is one of the reasons compilation of Ruby 3.2.0
to WASI fails with zig cc, while it works out of the box with clang.
But all applications checking for symbol existence before compilation
are affected.
This reverts the behavior to the one Zig had before #1622, and
introduces an `import_symbols` flag to ignore undefined symbols,
assuming that the webassembly runtime will define them.
Considering all possible features are known by the linker during
compile-time, we can create arrays on the stack instead of
dynamically allocating hash maps. We use a simple bitset to determine
whether a feature is enabled or not, and from which object file
it originates. This allows us to make feature validation slightly
faster and use less runtime memory.
In the future this could be enhanced further by having a single
array instead with a more sophisticated bitset.
This makes it easier to understand how control flow should happen in
various cases; already just by doing this it is revealed that
UndefinedSymbol and UndefinedSymbolReference should be merged, and that
MissingMainEntrypoint should be removed in favor of the ErrorFlags
mechanism thath we already have for missing the main entrypoint.
The main motivation for this change, however, is preventing a compile
error when there is conditional compilation inside linker
implementations, causing the flush() error set to depend on compilation
options. With this change, the error set is fixed, and, notably, the
`-Donly-c` flag no longer has compilation errors due to this error set.
This option can be used to produce a C backend build of the self-hosted
compiler, which only has the C backend enabled. Once the C backend is
capable of self-hosting, this will be a way for us to replace our stage1
codebase with a C backend build of self-hosted, which we can then use
for bootstrapping. See #5246 for more details.
Using this option right now results in a crash because the C backend is
not yet passing all the behavior tests.
Windows gives AccessDenied if you delete a directory which contains open
file handles. This could be triggered when using CacheMode.whole when
cross compiling macho test binaries.
