This commit introduces a new flag to generate a new Zig project using
`zig init` without comments for users who are already familiar with the
Zig build system.
Additionally, the generated files are now different. Previously we would
generate a set of files that defined a static library and an executable,
which real-life experience has shown to cause confusion to newcomers.
The new template generates one Zig module and one executable both in
order to accommodate the two most common use cases, but also to suggest
that a library could use a CLI tool (e.g. a parser library could use a
CLI tool that provides syntax checking) and vice-versa a CLI tool might
want to expose its core functionality as a Zig module.
All references to C interoperability are removed from the template under
the assumption that if you're tall enough to do C interop, you're also
tall enough to find your way around the build system. Experienced users
will still be able to use the current template and adapt it with minimal
changes in order to perform more advanced operations. As an example, one
only needs to change `b.addExecutable` to `b.addLibrary` to switch from
generating an executable to a dynamic (or static) library.
For instance, the file 'cases/compile_errors/undeclared_identifier.zig'
now corresponds to test name 'compile_errors.undeclared_identifier'.
This is useful because you can now filter based on the case dirname
using `-Dtest-filter`.
`castTruncatedData` was a poorly worded error (all shrinking casts
"truncate bits", it's just that we assume those bits to be zext/sext of
the other bits!), and `negativeToUnsigned` was a pointless distinction
which forced the compiler to emit worse code (since two separate safety
checks were required for casting e.g. 'i32' to 'u16') and wasn't even
implemented correctly. This commit combines those safety panics into one
function, `integerOutOfBounds`. The name maybe isn't perfect, but that's
not hugely important; what matters is the new default message, which is
clearer than the old ones: "integer does not fit in destination type".
Runtime `@shuffle` has two cases which backends generally want to handle
differently for efficiency:
* One runtime vector operand; some result elements may be comptime-known
* Two runtime vector operands; some result elements may be undefined
The latter case happens if both vectors given to `@shuffle` are
runtime-known and they are both used (i.e. the mask refers to them).
Otherwise, if the result is not entirely comptime-known, we are in the
former case. `Sema` now diffentiates these two cases in the AIR so that
backends can easily handle them however they want to. Note that this
*doesn't* really involve Sema doing any more work than it would
otherwise need to, so there's not really a negative here!
Most existing backends have their lowerings for `@shuffle` migrated in
this commit. The LLVM backend uses new lowerings suggested by Jacob as
ones which it will handle effectively. The x86_64 backend has not yet
been migrated; for now there's a panic in there. Jacob will implement
that before this is merged anywhere.
This adds 4 `Legalize.Feature`s:
* `expand_intcast_safe`
* `expand_add_safe`
* `expand_sub_safe`
* `expand_mul_safe`
These do pretty much what they say on the tin. This logic was previously
in Sema, used when `Zcu.Feature.safety_checked_instructions` was not
supported by the backend. That `Zcu.Feature` has been removed in favour
of this legalization.
We don't seem to be getting non-deterministic hangs since 4f3b59f, and e28b402
cut the run times significantly on top of that. Runs now seem to take around 1-2
hours, so the default timeout should be plenty.
This defines a WinMain() function that can be potentially problematic when it
isn't wanted. If we add back support for this library in the future, it should
be built separately from mingw32.lib and on demand.
Each target can opt into different sets of legalize features.
By performing these transformations before liveness, instructions
that become unreferenced will have up-to-date liveness information.
This is equivalent to `array_elem_val`, and doing that conversion in
Sema (seems reasonable since it's just a simple branch) is much easier
for the self-hosted x86_64 backend then actually handling this case.
Because we don't pass -fqemu and -fwasmtime on aarch64-linux, we're just
spending a bunch of time compiling all these module tests only to not even run
them. x86_64-linux already covers both compiling and running them.
Pointers to thread-local variables do not have their addresses known
until runtime, so it is nonsensical for them to be comptime-known. There
was logic in the compiler which was essentially attempting to treat them
as not being comptime-known despite the pointer being an interned value.
This was a bit of a mess, the check was frequent enough to actually show
up in compiler profiles, and it was very awkward for backends to deal
with, because they had to grapple with the fact that a "constant" they
were lowering might actually require runtime operations.
So, instead, do not consider these pointers to be comptime-known in
*any* way. Never intern such a pointer; instead, when the address of a
threadlocal is taken, emit an AIR instruction which computes the pointer
at runtime. This avoids lots of special handling for TLVs across
basically all codegen backends; of all somewhat-functional backends, the
only one which wasn't improved by this change was the LLVM backend,
because LLVM pretends this complexity around threadlocals doesn't exist.
This change simplifies Sema and codegen, avoids a potential source of
bugs, and potentially improves Sema performance very slightly by
avoiding a non-trivial check on a hot path.
