Since v0.23 release of Wasmtime, if we want to iterate a directory
Y then directory Y needed to have been granted `fd_readdir` right.
However, it is now also required for directory X to carry `fd_readdir`
right, and so on, up-chain all the way until we reach the preopen
(which possesses all rights by default).
This caused problems for us since our libstd implementation is more
fine-grained and allowed for parent dirs not to carry the right while
allow for iterating on its children. My proposal here is to always
grant `fd_readdir` right as part of
`std.fs.Dir.OpenDirOptions.access_sub_paths`. This seems to be the
approach taken by Rust also, plus we should be justified to take this
approach since WASI is experimental and snapshot1 will be discontinued
eventually and replaced with a new approach to access management
that will require a complete rewrite of our libstd anyhow.
Before this, if a compile error occurred, it would cause the previous
value for e.g. the function scope to not get reset. If the AstGen
process continued, it would result in a violation of the data
guarantees that it relies on.
This commit takes advantage of defer to ensure the previous value is
always reset, even in the case of an error.
Closes#8920
This allows us to differentiate between regular locals and variables that create multiple locals
on the stack such as optionals and structs.
Now `struct_a = struct_b;` works and only updates a reference, rather than update all local's values.
Also created more test cases to test against this.
- When returning within a block, we must use an explicit return opcode. For now always emit the opcode when calling return, rather than using implicit return statements.
- Also added a more comprehensive test case to test for enum values using conditions
When scanDecls happens, we create stub Decl objects that
have not been semantically analyzed. When they get referenced,
they get semantically analyzed.
Before this commit, when they got unreferenced, they were completely
deleted, including deleted from the containing Namespace.
However, if the update did not cause the containing Namespace to get
deleted, for example, if `std.builtin.ExportOptions` is no longer
referenced, but `std.builtin` is still referenced, and then `ExportOptions`
gets referenced again, the Namespace would be incorrectly missing the
Decl, so we get an incorrect "no such member" error.
The solution is to, when dealing with a no longer referenced Decl
objects during an update, clear them to the state they would be in
on a fresh scanDecl, rather than completely deleting them.
Conflicts:
* src/codegen/spirv.zig
* src/link/SpirV.zig
We're going to want to improve the stage2 test harness to print
the source file name when a compile error occurs otherwise std lib
contributors are going to see some confusing CI failures when they cause
stage2 AstGen compile errors.
In order for this test to pass, the host linking/start code needs to
support explicitly setting the stack size. Zig defaults to 16 MiB stack
size, which is enough to pass the test in Debug builds, however, most
operating systems do not honor the stack size we request for and give a
smaller amount.
Eventually the goal is to pass this test on all hosts.
* Advance line and PC prior to ending sequence in debug line program
for a fn_decl. This is equivalent to closing scope in the debugger
and without it, the debugger will not map source-to-address info
as a result will not print the source when breaking at a symbol.
* Fix debug aranges sentinels to be of the size as the actual tuple
descriptor (assuming segment selector to be ommitted). In summary,
the sentinels were 32bit 0s, whereas they ought to be 64bit 0s.
* Make naming of symbols in the binary more consistent by prefixing
each symbol name with an underscore '_'.
Conflicts:
* build.zig
* src/Compilation.zig
* src/codegen/spirv/spec.zig
* src/link/SpirV.zig
* test/stage2/darwin.zig
- this one might be problematic; start.zig looks for `main` in the
root source file, not `_main`. Not sure why there is an underscore
there in master branch.
As it stands, the backend is incomplete, and there is no active contributor,
making it dead weight.
However, anyone is free to resurrect this backend at any time.
Just like when new parse errors occur during an update, when new AstGen
errors occur during an update, we do not reveal compile errors for Decl
objects which are inside of a newly failed File. Once the File passes
AstGen successfully, it will be compared with the previously succeeded
ZIR and the saved Decl compile errors will be handled properly.
* Do not report export collision errors until the very end, because it
is possible, during an update, for a new export to be added before an
old one is semantically analyzed to be deleted. In such a case there
should be no compile error.
- Likewise we defer emitting exports until the end when we know for
sure what will happen.
* Sema: Fix not adding a Decl dependency on imported files.
* Sema: Properly add Decl dependencies for all identifier and namespace
lookups.
* After semantic analysis for a Decl, if it is still marked as
`in_progress`, change it to `dependency_failure` because if the Decl
itself failed, it would have already been changed during the call to
add the compile error.
* Remove the ability for GenZir parent Scope to be null. Now there is a
Top Scope at the top.
* Introduce Scope.Namespace to contain a table of decl names in order
to emit a compile error for name conflicts.
* Fix use of invalid memory when reporting compile errors by
duplicating decl names into a temporary heap allocated buffer.
* Fix memory leak in while and for loops, not cleaning up their
labeled_breaks and store_to_block_ptr_list arrays.
* Fix stage2 test cases because now the source location of redundant
comptime keyword compile errors is improved.
* Implement compile error for local variable shadowing declaration.
Conflicts:
* lib/std/os/linux.zig
* lib/std/os/windows/bits.zig
* src/Module.zig
* src/Sema.zig
* test/stage2/test.zig
Mainly I wanted Jakub's new macOS code for respecting stack size, since
we now depend on it for debug builds able to pass one of the test cases
for recursive comptime function calls with `@setEvalBranchQuota`.
The conflicts were all trivial.
* Compilation: iteration over the deletion_set only tries to delete the
first one, relying on Decl destroy to remove itself from the deletion
set.
* link: `freeDecl` now has to handle the possibility of freeing a Decl
that was never called with `allocateDeclIndexes`.
* `deleteDecl` recursively iterates over a Decl's Namespace sub-Decl
objects and calls `deleteDecl` on them.
- Prevents Decl objects from being destroyed when they are still in
`deletion_set`.
* Sema: fix cleanup of anonymous Decl objects when an error occurs
during semantic analysis.
* tests: update test cases for fully qualified names
Decl objects need to know whether they are the owner of the Type/Value
associated with them, in order to decide whether to destroy the
associated Namespace, Fn, or Var when cleaning up.
* Sema: implement global variables
- Improved global constants to stop needlessly creating a Var
structure; they can just store the value directly.
- This required making memory management a bit more sophisticated to
detect when a Decl owns the Namespace associated with it, for the
purposes of deinitialization.
* Decl.name and Namespace decl table keys no longer directly
reference ZIR; instead they have heap-duped names, so that deleted
decls, which no longer have any ZIR to reference for their names, can
be removed from the parent Namespace table.
- In the future I would like to explore going a different direction
with this, where the strings would still point to the ZIR however
they would be removed from their owner Namespace objects during the
update detection. The design principle here is that the existence
of incremental compilation as a feature should not incur any cost
for the use case when it is not used. In this example Decl names
could simply point to ZIR string table memory, and it is only
because of incremental compilation that we duplicate their names.
* AstGen: implement threadlocal variables
* CLI: call cleanExit after building a compilation so that in release
modes we don't bother freeing memory or closing file descriptors,
allowing the OS to do it more efficiently.
* Avoid calling `freeDecl` in the linker for unreferenced Decl objects.
* Fix CBE test case expecting the compile error to point to the wrong
column.
This was also an experiment to see if it were easier to implement a new
feature when using the instruction encoder.
Verdict: It's not that much easier, but I think it's certainly much more
readable, because the description of the Instruction annotates what each
field means. Right now, precise knowledge of x86_64 instructions is
still required because things like when to set the 64-bit flag, how to
read x86_64 instruction references, etc. are still not automatically
done for you.
In the future, this interface might make it sligtly easier to write an
assembler for x86_64, by abstracting the bit-fiddling aspects of
instruction encoding.
From my very cursory reading, it seems that the register manager doesn't
distinguish between registers that are physically the same but have
different sizes.
In that case, this means that during codegen, we can't rely on
`reg.size()` when determining the width of the operations we have to
perform. Instead, we must use some form of `ty.abiSize(self.target.*)`
to determine the size of the type we're operating with. If this size is
64 bits, then we should enable 64-bit operation.
This fixed a bug in the codegen for spilling instructions, which was
overwriting the previous stack entry with zeroes. See the modified test
case in this commit.
