Introduces std.zig.ErrorBundle which is a trivially serializeable set
of compilation errors. This is in the standard library so that both
the compiler and the build runner can use it. The idea is they will
use it to communicate compilation errors over a binary protocol.
The binary encoding of ErrorBundle is a bit problematic - I got a little
too aggressive with compaction. I need to change it in a follow-up
commit to use some indirection in the error message list, otherwise
iteration is too unergonomic. In fact it's so problematic right now that
the logic getAllErrorsAlloc() actually fails to produce a viable
ErrorBundle because it puts SourceLocation data in between the root
level ErrorMessage data.
This commit has a simplification - redundant logic for rendering AST
errors to stderr has been removed in favor of moving the logic for
lowering AST errors into AstGen. So even if we get parse errors, the
errors will get lowered into ZIR before being reported. I believe this
will be useful when working on --autofix. Either way, some redundant
brittle logic was happily deleted.
In Compilation, updateSubCompilation() is improved to properly perform
error reporting when a sub-compilation object fails. It no longer dumps
directly to stderr; instead it populates an ErrorBundle object, which
gets added to the parent one during getAllErrorsAlloc().
In package fetching code, instead of dumping directly to stderr, it now
populates an ErrorBundle object, and gets properly reported at the CLI
layer of abstraction.
- improve fn prototypes of process_vm_writev
- make the memory writable in the ELF file
- force the linker to always append the function
- write updates with process_vm_writev
Previously, if you had a pointer to multiple array elements and tried to
write to it at comptime, it was incorrectly treated as a pointer to one
specific array value, leading to an assertion down the line. If we try
to mutate a value at an elem_ptr larger than the element type, we need
to perform a modification to multiple array elements.
This solution isn't ideal, since it will result in storePtrVal
serializing the whole array, modifying the relevant parts, and storing
it back. Ideally, it would only take the required elements. However,
this change would have been more complex, and this is a fairly rare
operation (nobody ever ran into the bug before after all), so it doesn't
matter all that much.
* There was an edge case where the arena could be destroyed twice on
error: once from the arena itself and once from the decl destruction.
* The type of the created decl was incorrect (it should have been the
pointer child type), but it's not required anyway, so it's now just
initialized to anyopaque (which more accurately reflects what's
actually at that memory, since e.g. [*]T may correspond to nothing).
* A runtime bitcast of the pointer was performed, meaning @extern didn't
work at comptime. This is unnecessary: the decl_ref can just be
initialized with the correct pointer type.
