Call start/endBlock before/after `parseBlockInfoBlock` in order to not
use the current block context, which is wrong and leads to e.g. incorrect
abbrevlen being used.
This "get" is useless noise and was copied from FixedBufferWriter.
Since this API has not yet landed in a release, now is a good time
to make the breaking change to fix this.
The functions `Compilation.create` and `Compilation.update` previously
returned inferred error sets, which had built up a lot of crap over
time. This meant that certain error conditions -- particularly certain
filesystem errors -- were not being reported properly (at best the CLI
would just print the error name). This was also a problem in
sub-compilations, where at times only the error name -- which might just
be something like `LinkFailed` -- would be visible.
This commit makes the error handling here more disciplined by
introducing concrete error sets to these functions (and a few more as a
consequence). These error sets are small: errors in `update` are almost
all reported via compile errors, and errors in `create` are reported
through a new `Compilation.CreateDiagnostic` type, a tagged union of
possible error cases. This allows for better error reporting.
Sub-compilations also report errors more correctly in several cases,
leading to more informative errors in the case of compiler bugs.
Also fixes some race conditions in library building by replacing calls
to `setMiscFailure` with calls to `lockAndSetMiscFailure`. Compilation
of libraries such as libc happens on the thread pool, so the logic must
synchronize its access to shared `Compilation` state.
If both are used, 'else' handles named members and '_' handles
unnamed members. In this case the 'else' prong will be unrolled
to an explicit case containing all remaining named values.
Mainly affects ZIR representation of switch_block[_ref]
and special prong (detection) logic for switch.
Adds a new SpecialProng tag 'absorbing_under' that allows
specifying additional explicit tags in a '_' prong which
are respected when checking that every value is handled
during semantic analysis but are not transformed into AIR
and instead 'absorbed' by the '_' branch.
This commit replaces the "fuzzer" UI, previously accessed with the
`--fuzz` and `--port` flags, with a more interesting web UI which allows
more interactions with the Zig build system. Most notably, it allows
accessing the data emitted by a new "time report" system, which allows
users to see which parts of Zig programs take the longest to compile.
The option to expose the web UI is `--webui`. By default, it will listen
on `[::1]` on a random port, but any IPv6 or IPv4 address can be
specified with e.g. `--webui=[::1]:8000` or `--webui=127.0.0.1:8000`.
The options `--fuzz` and `--time-report` both imply `--webui` if not
given. Currently, `--webui` is incompatible with `--watch`; specifying
both will cause `zig build` to exit with a fatal error.
When the web UI is enabled, the build runner spawns the web server as
soon as the configure phase completes. The frontend code consists of one
HTML file, one JavaScript file, two CSS files, and a few Zig source
files which are built into a WASM blob on-demand -- this is all very
similar to the old fuzzer UI. Also inherited from the fuzzer UI is that
the build system communicates with web clients over a WebSocket
connection.
When the build finishes, if `--webui` was passed (i.e. if the web server
is running), the build runner does not terminate; it continues running
to serve web requests, allowing interactive control of the build system.
In the web interface is an overall "status" indicating whether a build
is currently running, and also a list of all steps in this build. There
are visual indicators (colors and spinners) for in-progress, succeeded,
and failed steps. There is a "Rebuild" button which will cause the build
system to reset the state of every step (note that this does not affect
caching) and evaluate the step graph again.
If `--time-report` is passed to `zig build`, a new section of the
interface becomes visible, which associates every build step with a
"time report". For most steps, this is just a simple "time taken" value.
However, for `Compile` steps, the compiler communicates with the build
system to provide it with much more interesting information: time taken
for various pipeline phases, with a per-declaration and per-file
breakdown, sorted by slowest declarations/files first. This feature is
still in its early stages: the data can be a little tricky to
understand, and there is no way to, for instance, sort by different
properties, or filter to certain files. However, it has already given us
some interesting statistics, and can be useful for spotting, for
instance, particularly complex and slow compile-time logic.
Additionally, if a compilation uses LLVM, its time report includes the
"LLVM pass timing" information, which was previously accessible with the
(now removed) `-ftime-report` compiler flag.
To make time reports more useful, ZIR and compilation caches are ignored
by the Zig compiler when they are enabled -- in other words, `Compile`
steps *always* run, even if their result should be cached. This means
that the flag can be used to analyze a project's compile time without
having to repeatedly clear cache directory, for instance. However, when
using `-fincremental`, updates other than the first will only show you
the statistics for what changed on that particular update. Notably, this
gives us a fairly nice way to see exactly which declarations were
re-analyzed by an incremental update.
If `--fuzz` is passed to `zig build`, another section of the web
interface becomes visible, this time exposing the fuzzer. This is quite
similar to the fuzzer UI this commit replaces, with only a few cosmetic
tweaks. The interface is closer than before to supporting multiple fuzz
steps at a time (in line with the overall strategy for this build UI,
the goal will be for all of the fuzz steps to be accessible in the same
interface), but still doesn't actually support it. The fuzzer UI looks
quite different under the hood: as a result, various bugs are fixed,
although other bugs remain. For instance, viewing the source code of any
file other than the root of the main module is completely broken (as on
master) due to some bogus file-to-module assignment logic in the fuzzer
UI.
Implementation notes:
* The `lib/build-web/` directory holds the client side of the web UI.
* The general server logic is in `std.Build.WebServer`.
* Fuzzing-specific logic is in `std.Build.Fuzz`.
* `std.Build.abi` is the new home of `std.Build.Fuzz.abi`, since it now
relates to the build system web UI in general.
* The build runner now has an **actual** general-purpose allocator,
because thanks to `--watch` and `--webui`, the process can be
arbitrarily long-lived. The gpa is `std.heap.DebugAllocator`, but the
arena remains backed by `std.heap.page_allocator` for efficiency. I
fixed several crashes caused by conflation of `gpa` and `arena` in the
build runner and `std.Build`, but there may still be some I have
missed.
* The I/O logic in `std.Build.WebServer` is pretty gnarly; there are a
*lot* of threads involved. I anticipate this situation improving
significantly once the `std.Io` interface (with concurrency support)
is introduced.
Basically everything that has a direct replacement or no uses left.
Notable omissions:
- std.ArrayHashMap: Too much fallout, needs a separate cleanup.
- std.debug.runtime_safety: Too much fallout.
- std.heap.GeneralPurposeAllocator: Lots of references to it remain, not
a simple find and replace as "debug allocator" is not equivalent to
"general purpose allocator".
- std.io.Reader: Is being reworked at the moment.
- std.unicode.utf8Decode(): No replacement, needs a new API first.
- Manifest backwards compat options: Removal would break test data used
by TestFetchBuilder.
- panic handler needs to be a namespace: Many tests still rely on it
being a function, needs a separate cleanup.
Alignment and fill options only apply to numbers.
Rework the implementation to mainly branch on the format string rather
than the type information. This is more straightforward to maintain and
more straightforward for comptime evaluation.
Enums support being printed as decimal, hexadecimal, octal, and binary.
`formatInteger` is another possible format method that is
unconditionally called when the value type is struct and one of the
integer-printing format specifiers are used.
