For the supported COFF machine types of X64 (x86_64), I386 (x86), ARMNT (thumb), and ARM64 (aarch64), this new Zig implementation results in byte-for-byte identical .lib files when compared to the previous LLVM-backed implementation.
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.
LLVM recently introduced new Triple::ArchType members in 19.1.3 which broke our
static assertions in zig_llvm.cpp. When implementing a fix for that, I realized
that we don't even need a lot of the stuff we have in zig_llvm.(cpp,h) anymore.
This commit trims the interface down considerably.
Passing it by value means that bringup on new architectures is harder for no
real benefit. Passing it by pointer allows to get the compiler running without
needing to figure out the C calling convention details first. This manifested in
practice on LoongArch, for example.
matching the default of clang's behavior. I originally put them in
registerOptimizerEarlyEPCallback because I thought clang was doing that,
but I see now it is behind the flag `--sanitizer-early-opt-ep` which is
disabled by default.
The `TargetOptions` default constructor initializes all `bool`s to
`false`, yet clang defaults to setting this option to `true`. Since
recent glibc versions on linux do not appear to support this being set
to `false`, just changing the default for now unless a use case for
making it configurable is found.
Exposes sanitizer coverage flags to the target machine emit function.
Makes it easier to change sancov options without rebuilding the C++
files.
This also enables PCTable = true for sancov which is needed by AFL, and
adds the corresponding Clang flag.
* Add the `-ffuzz` and `-fno-fuzz` CLI arguments.
* Detect fuzz testing flags from zig cc.
* Set the correct clang flags when fuzz testing is requested. It can be
combined with TSAN and UBSAN.
* Compilation: build fuzzer library when needed which is currently an
empty zig file.
* Add optforfuzzing to every function in the llvm backend for modules
that have requested fuzzing.
* In ZigLLVMTargetMachineEmitToFile, add the optimization passes for
sanitizer coverage.
* std.mem.eql uses a naive implementation optimized for fuzzing when
builtin.fuzz is true.
Tracked by #20702
New OSs:
* XROS
* Serenity
* Vulkan
Removed OSs:
* Ananas
* CloudABI
* Minix
* Contiki
New CPUs:
* spirv
The removed stuff is removed from LLVM but not Zig.
The signature is `getOrCreateSubrange(int64_t Lo, int64_t Count)`, so this updates the bindings to match.
This fixes a crash in `lowerDebugTypeImpl` when analyzing slices that have a length of 2^32 or
larger (up to `2^64 >> 3`, which still crashes, because above that the array size in bits overflows u64).
This commit enables producing 64-bit DWARF format for Zig executables
that are produced through the LLVM backend. This is achieved by exposing
both command-line flags and CompileStep flags. The production of the
64-bit format only affects binaries that use the DWARF format and it is
disabled on MacOS due to it being problematic. This commit, despite
generating the interface for the Zig user to be able to tell the compile
which format is wanted, is just implemented for the LLVM backend, so
clang and the self-hosted backends will need this to be implemented in a
future commit.
This is an effort to work around #7962, since the emission of the 64-bit
format automatically produces 64-bit relocations. Further investigation
will be needed to make DWARF 32-bit format to emit bigger relocations
when needed and not make the linker angry.
This commit changes the way Zig is intended to deal with variable
declaration for exotic targets. Where previously the idea was to
enfore local/global variables to be placed into their respective
address spaces, depending on the target, this is now fixed to the
generic address space.
To facilitate this for targets where local variables _must_ be
generated into a specific address space (ex. amdgcn where locals
must be generated into the private address space), the variable
allocations (alloca) are generated into the right address space
and then addrspace-casted back to the generic address space. While this
could be less efficient in theory, LLVM will hopefull deal with figuring
out the actual correct address space for a pointer for us. HIP seems to
do the same thing in this regard.
Global variables are handled in a similar way.
As part of the Opaque Pointers upgrade documentation, LLVM says that the
function LLVMGetGEPSourceElementType() can be used to obtain element
type information in lieu of LLVMGetElementType(), however, this function
actually returns the struct type, not the field type. The GEP
instruction does store the information we need, however, this is not
exposed in the C API. It seems like they accidentally exposed the wrong
field, because one would never need the struct type since one must
already pass it directly to the GEP instruction, so one will always have
it handy, whereas one will usually not have the field type handy.
