aboutsummaryrefslogtreecommitdiff
path: root/src/link/Coff.zig
AgeCommit message (Collapse)Author
2025-10-30Merge pull request #25558 from jacobly0/elfv2-load-objJacob Young
Elf2: start implementing input object loading
2025-10-30std.debug.lockStderrWriter: also return ttyconfMatthew Lugg
`std.Io.tty.Config.detect` may be an expensive check (e.g. involving syscalls), and doing it every time we need to print isn't really necessary; under normal usage, we can compute the value once and cache it for the whole program's execution. Since anyone outputting to stderr may reasonably want this information (in fact they are very likely to), it makes sense to cache it and return it from `lockStderrWriter`. Call sites who do not need it will experience no significant overhead, and can just ignore the TTY config with a `const w, _` destructure.
2025-10-29Elf2: start implementing input object loadingJacob Young
2025-10-29coff linker: don't check the timeAndrew Kelley
compiler toolchains have no business knowing what time it is
2025-10-10Coff: implement threadlocal variablesJacob Young
2025-10-06Elf2: implement virtual allocationJacob Young
This allows segments to be moved around in the output file without needing to reapply relocations until virtual address space is exhaused.
2025-10-02Coff: deleteJacob Young
2025-10-02Coff2: create a new linker from scratchJacob Young
2025-09-21Elf2: create a new linker from scratchJacob Young
This iteration already has significantly better incremental support. Closes #24110
2025-09-08fix linker code writing undefined memory to the output fileAndrew Kelley
missing `extern` on a struct. but also all these instances that call pwriteAll with a `@ptrCast` are endianness bugs. this should be changed to use File.Writer and call writeSliceEndian instead. this commit fixes one immediate problem but does not fix everything.
2025-08-31std.fmt: delete deprecated APIsAndrew Kelley
std.fmt.Formatter -> std.fmt.Alt std.fmt.format -> std.Io.Writer.print
2025-08-29std.Io: delete GenericReaderAndrew Kelley
and delete deprecated alias std.io
2025-08-28more updates to not use GenericWriterAndrew Kelley
2025-08-12Sema: Improve comptime arithmetic undef handlingJustus Klausecker
This commit expands on the foundations laid by https://github.com/ziglang/zig/pull/23177 and moves even more `Sema`-only functionality from `Value` to `Sema.arith`. Specifically all shift and bitwise operations, `@truncate`, `@bitReverse` and `@byteSwap` have been moved and adapted to the new rules around `undefined`. Especially the comptime shift operations have been basically rewritten, fixing many open issues in the process. New rules applied to operators: * `<<`, `@shlExact`, `@shlWithOverflow`, `>>`, `@shrExact`: compile error if any operand is undef * `<<|`, `~`, `^`, `@truncate`, `@bitReverse`, `@byteSwap`: return undef if any operand is undef * `&`, `|`: Return undef if both operands are undef, turn undef into actual `0xAA` bytes otherwise Additionally this commit canonicalizes the representation of aggregates with all-undefined members in the `InternPool` by disallowing them and enforcing the usage of a single typed `undef` value instead. This reduces the amount of edge cases and fixes a bunch of bugs related to partially undefined vecs. List of operations directly affected by this patch: * `<<`, `<<|`, `@shlExact`, `@shlWithOverflow` * `>>`, `@shrExact` * `&`, `|`, `~`, `^` and their atomic rmw + reduce pendants * `@truncate`, `@bitReverse`, `@byteSwap`
2025-08-11std.ArrayList: make unmanaged the defaultAndrew Kelley
2025-07-22aarch64: add new from scratch self-hosted backendJacob Young
2025-07-07compiler: update a bunch of format stringsAndrew Kelley
2025-07-07compiler: fix a bunch of format stringsAndrew Kelley
2025-07-07compiler: fix a bunch of format stringsAndrew Kelley
2025-07-07compiler: update all instances of std.fmt.FormatterAndrew Kelley
2025-07-07std.fmt: breaking API changesAndrew Kelley
added adapter to AnyWriter and GenericWriter to help bridge the gap between old and new API make std.testing.expectFmt work at compile-time std.fmt no longer has a dependency on std.unicode. Formatted printing was never properly unicode-aware. Now it no longer pretends to be. Breakage/deprecations: * std.fs.File.reader -> std.fs.File.deprecatedReader * std.fs.File.writer -> std.fs.File.deprecatedWriter * std.io.GenericReader -> std.io.Reader * std.io.GenericWriter -> std.io.Writer * std.io.AnyReader -> std.io.Reader * std.io.AnyWriter -> std.io.Writer * std.fmt.format -> std.fmt.deprecatedFormat * std.fmt.fmtSliceEscapeLower -> std.ascii.hexEscape * std.fmt.fmtSliceEscapeUpper -> std.ascii.hexEscape * std.fmt.fmtSliceHexLower -> {x} * std.fmt.fmtSliceHexUpper -> {X} * std.fmt.fmtIntSizeDec -> {B} * std.fmt.fmtIntSizeBin -> {Bi} * std.fmt.fmtDuration -> {D} * std.fmt.fmtDurationSigned -> {D} * {} -> {f} when there is a format method * format method signature - anytype -> *std.io.Writer - inferred error set -> error{WriteFailed} - options -> (deleted) * std.fmt.Formatted - now takes context type explicitly - no fmt string
2025-06-19x86_64: increase passing test coverage on windowsJacob Young
Now that codegen has no references to linker state this is much easier. Closes #24153
2025-06-19coff: add hack to build a compiler-rt dynamic libraryJacob Young
This is not meant to be a long-term solution, but it's the easiest thing to get working quickly at the moment. The main intention of this hack is to allow more tests to be enabled. By the time the coff linker is far enough along to be enabled by default, this will no longer be required.
2025-06-19Target: pass and use locals by pointer instead of by valueJacob Young
This struct is larger than 256 bytes and code that copies it consistently shows up in profiles of the compiler.
2025-06-12x86_64: implement coff relocationsJacob Young
2025-06-12x86_64: remove air references from mirJacob Young
2025-06-12compiler: rework emit paths and cache modesmlugg
Previously, various doc comments heavily disagreed with the implementation on both what lives where on the filesystem at what time, and how that was represented in code. Notably, the combination of emit paths outside the cache and `disable_lld_caching` created a kind of ad-hoc "cache disable" mechanism -- which didn't actually *work* very well, 'most everything still ended up in this cache. There was also a long-standing issue where building using the LLVM backend would put a random object file in your cwd. This commit reworks how emit paths are specified in `Compilation.CreateOptions`, how they are represented internally, and how the cache usage is specified. There are now 3 options for `Compilation.CacheMode`: * `.none`: do not use the cache. The paths we have to emit to are relative to the compiler cwd (they're either user-specified, or defaults inferred from the root name). If we create any temporary files (e.g. the ZCU object when using the LLVM backend) they are emitted to a directory in `local_cache/tmp/`, which is deleted once the update finishes. * `.whole`: cache the compilation based on all inputs, including file contents. All emit paths are computed by the compiler (and will be stored as relative to the local cache directory); it is a CLI error to specify an explicit emit path. Artifacts (including temporary files) are written to a directory under `local_cache/tmp/`, which is later renamed to an appropriate `local_cache/o/`. The caller (who is using `--listen`; e.g. the build system) learns the name of this directory, and can get the artifacts from it. * `.incremental`: similar to `.whole`, but Zig source file contents, and anything else which incremental compilation can handle changes for, is not included in the cache manifest. We don't need to do the dance where the output directory is initially in `tmp/`, because our digest is computed entirely from CLI inputs. To be clear, the difference between `CacheMode.whole` and `CacheMode.incremental` is unchanged. `CacheMode.none` is new (previously it was sort of poorly imitated with `CacheMode.whole`). The defined behavior for temporary/intermediate files is new. `.none` is used for direct CLI invocations like `zig build-exe foo.zig`. The other cache modes are reserved for `--listen`, and the cache mode in use is currently just based on the presence of the `-fincremental` flag. There are two cases in which `CacheMode.whole` is used despite there being no `--listen` flag: `zig test` and `zig run`. Unless an explicit `-femit-bin=xxx` argument is passed on the CLI, these subcommands will use `CacheMode.whole`, so that they can put the output somewhere without polluting the cwd (plus, caching is potentially more useful for direct usage of these subcommands). Users of `--listen` (such as the build system) can now use `std.zig.EmitArtifact.cacheName` to find out what an output will be named. This avoids having to synchronize logic between the compiler and all users of `--listen`.
2025-06-12compiler: get most backends compiling againmlugg
As of this commit, every backend other than self-hosted Wasm and self-hosted SPIR-V compiles and (at least somewhat) functions again. Those two backends are currently disabled with panics. Note that `Zcu.Feature.separate_thread` is *not* enabled for the fixed backends. Avoiding linker references from codegen is a non-trivial task, and can be done after this branch.
2025-06-12compiler: rework backend pipeline to separate codegen and linkmlugg
The idea here is that instead of the linker calling into codegen, instead codegen should run before we touch the linker, and after MIR is produced, it is sent to the linker. Aside from simplifying the call graph (by preventing N linkers from each calling into M codegen backends!), this has the huge benefit that it is possible to parallellize codegen separately from linking. The threading model can look like this: * 1 semantic analysis thread, which generates AIR * N codegen threads, which process AIR into MIR * 1 linker thread, which emits MIR to the binary The codegen threads are also responsible for `Air.Legalize` and `Air.Liveness`; it's more efficient to do this work here instead of blocking the main thread for this trivially parallel task. I have repurposed the `Zcu.Feature.separate_thread` backend feature to indicate support for this 1:N:1 threading pattern. This commit makes the C backend support this feature, since it was relatively easy to divorce from `link.C`: it just required eliminating some shared buffers. Other backends don't currently support this feature. In fact, they don't even compile -- the next few commits will fix them back up.
2025-06-12link: divorce LLD from the self-hosted linkersmlugg
Similar to the previous commit, this commit untangles LLD integration from the self-hosted linkers. Despite the big network of functions which were involved, it turns out what was going on here is quite simple. The LLD linking logic is actually very self-contained; it requires a few flags from the `link.File.OpenOptions`, but that's really about it. We don't need any of the mutable state on `Elf`/`Coff`/`Wasm`, for instance. There was some legacy code trying to handle support for using self-hosted codegen with LLD, but that's not a supported use case, so I've just stripped it out. For now, I've just pasted the logic for linking the 3 targets we currently support using LLD for into this new linker implementation, `link.Lld`; however, it's almost certainly possible to combine some of the logic and simplify this file a bit. But to be honest, it's not actually that bad right now. This commit ends up eliminating the distinction between `flush` and `flushZcu` (formerly `flushModule`) in linkers, where the latter previously meant something along the lines of "flush, but if you're going to be linking with LLD, just flush the ZCU object file, don't actually link"?. The distinction here doesn't seem like it was properly defined, and most linkers seem to treat them as essentially identical anyway. Regardless, all calls to `flushZcu` are gone now, so it's deleted -- one `flush` to rule them all! The end result of this commit and the preceding one is that LLVM and LLD fit into the pipeline much more sanely: * If we're using LLVM for the ZCU, that state is on `zcu.llvm_object` * If we're using LLD to link, then the `link.File` is a `link.Lld` * Calls to "ZCU link functions" (e.g. `updateNav`) lower to calls to the LLVM object if it's available, or otherwise to the `link.File` if it's available (neither is available under `-fno-emit-bin`) * After everything is done, linking is finalized by calling `flush` on the `link.File`; for `link.Lld` this invokes LLD, for other linkers it flushes self-hosted linker state There's one messy thing remaining, and that's how self-hosted function codegen in a ZCU works; right now, we process AIR with a call sequence something like this: * `link.doTask` * `Zcu.PerThread.linkerUpdateFunc` * `link.File.updateFunc` * `link.Elf.updateFunc` * `link.Elf.ZigObject.updateFunc` * `codegen.generateFunction` * `arch.x86_64.CodeGen.generate` So, we start in the linker, take a scenic detour through `Zcu`, go back to the linker, into its implementation, and then... right back out, into code which is generic over the linker implementation, and then dispatch on the *backend* instead! Of course, within `arch.x86_64.CodeGen`, there are some more places which switch on the `link` implementation being used. This is all pretty silly... so it shall be my next target.
2025-06-12compiler: slightly untangle LLVM from the linkersmlugg
The main goal of this commit is to make it easier to decouple codegen from the linkers by being able to do LLVM codegen without going through the `link.File`; however, this ended up being a nice refactor anyway. Previously, every linker stored an optional `llvm.Object`, which was populated when using LLVM for the ZCU *and* linking an output binary; and `Zcu` also stored an optional `llvm.Object`, which was used only when we needed LLVM for the ZCU (e.g. for `-femit-llvm-bc`) but were not emitting a binary. This situation was incredibly silly. It meant there were N+1 places the LLVM object might be instead of just 1, and it meant that every linker had to start a bunch of methods by checking for an LLVM object, and just dispatching to the corresponding method on *it* instead if it was not `null`. Instead, we now always store the LLVM object on the `Zcu` -- which makes sense, because it corresponds to the object emitted by, well, the Zig Compilation Unit! The linkers now mostly don't make reference to LLVM. `Compilation` makes sure to emit the LLVM object if necessary before calling `flush`, so it is ready for the linker. Also, all of the `link.File` methods which act on the ZCU -- like `updateNav` -- now check for the LLVM object in `link.zig` instead of in every single individual linker implementation. Notably, the change to LLVM emit improves this rather ludicrous call chain in the `-fllvm -flld` case: * Compilation.flush * link.File.flush * link.Elf.flush * link.Elf.linkWithLLD * link.Elf.flushModule * link.emitLlvmObject * Compilation.emitLlvmObject * llvm.Object.emit Replacing it with this one: * Compilation.flush * llvm.Object.emit ...although we do currently still end up in `link.Elf.linkWithLLD` to do the actual linking. The logic for invoking LLD should probably also be unified at least somewhat; I haven't done that in this commit.
2025-06-04compiler: Don't link ucrtbased.dll when targeting *-windows-msvc in Debug mode.Alex Rønne Petersen
Linking it by default means that we produce binaries that, effectively, only run on systems which have the Windows SDK installed because ucrtbased.dll is not redistributable, and the Windows SDK is what actually installs ucrtbased.dll into %SYSTEM32%. The resulting binaries also can't run under Wine because Wine does not provide ucrtbased.dll. It is also inconsistent with our behavior for *-windows-gnu where we always link ucrtbase.dll. See #23983, #24019, and #24053 for more details. So just use ucrtbase.dll regardless of mode. With this change, we can also drop the implicit definition of the _DEBUG macro in zig cc, which has in some cases been problematic for users. Users who want to opt into the old behavior can do so, both for *-windows-msvc and *-windows-gnu, by explicitly passing -lucrtbased and -D_DEBUG. We might consider adding a more ergonomic flag like -fdebug-crt to the zig build-* family of commands in the future. Closes #24052.
2025-05-29Legalize: introduce a new pass before livenessJacob Young
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.
2025-05-18compiler: refactor `Zcu.File` and path representationmlugg
This commit makes some big changes to how we track state for Zig source files. In particular, it changes: * How `File` tracks its path on-disk * How AstGen discovers files * How file-level errors are tracked * How `builtin.zig` files and modules are created The original motivation here was to address incremental compilation bugs with the handling of files, such as #22696. To fix this, a few changes are necessary. Just like declarations may become unreferenced on an incremental update, meaning we suppress analysis errors associated with them, it is also possible for all imports of a file to be removed on an incremental update, in which case file-level errors for that file should be suppressed. As such, after AstGen, the compiler must traverse files (starting from analysis roots) and discover the set of "live files" for this update. Additionally, the compiler's previous handling of retryable file errors was not very good; the source location the error was reported as was based only on the first discovered import of that file. This source location also disappeared on future incremental updates. So, as a part of the file traversal above, we also need to figure out the source locations of imports which errors should be reported against. Another observation I made is that the "file exists in multiple modules" error was not implemented in a particularly good way (I get to say that because I wrote it!). It was subject to races, where the order in which different imports of a file were discovered affects both how errors are printed, and which module the file is arbitrarily assigned, with the latter in turn affecting which other files are considered for import. The thing I realised here is that while the AstGen worker pool is running, we cannot know for sure which module(s) a file is in; we could always discover an import later which changes the answer. So, here's how the AstGen workers have changed. We initially ensure that `zcu.import_table` contains the root files for all modules in this Zcu, even if we don't know any imports for them yet. Then, the AstGen workers do not need to be aware of modules. Instead, they simply ignore module imports, and only spin off more workers when they see a by-path import. During AstGen, we can't use module-root-relative paths, since we don't know which modules files are in; but we don't want to unnecessarily use absolute files either, because those are non-portable and can make `error.NameTooLong` more likely. As such, I have introduced a new abstraction, `Compilation.Path`. This type is a way of representing a filesystem path which has a *canonical form*. The path is represented relative to one of a few special directories: the lib directory, the global cache directory, or the local cache directory. As a fallback, we use absolute (or cwd-relative on WASI) paths. This is kind of similar to `std.Build.Cache.Path` with a pre-defined list of possible `std.Build.Cache.Directory`, but has stricter canonicalization rules based on path resolution to make sure deduplicating files works properly. A `Compilation.Path` can be trivially converted to a `std.Build.Cache.Path` from a `Compilation`, but is smaller, has a canonical form, and has a digest which will be consistent across different compiler processes with the same lib and cache directories (important when we serialize incremental compilation state in the future). `Zcu.File` and `Zcu.EmbedFile` both contain a `Compilation.Path`, which is used to access the file on-disk; module-relative sub paths are used quite rarely (`EmbedFile` doesn't even have one now for simplicity). After the AstGen workers all complete, we know that any file which might be imported is definitely in `import_table` and up-to-date. So, we perform a single-threaded graph traversal; similar to what `resolveReferences` plays for `AnalUnit`s, but for files instead. We figure out which files are alive, and which module each file is in. If a file turns out to be in multiple modules, we set a field on `Zcu` to indicate this error. If a file is in a different module to a prior update, we set a flag instructing `updateZirRefs` to invalidate all dependencies on the file. This traversal also discovers "import errors"; these are errors associated with a specific `@import`. With Zig's current design, there is only one possible error here: "import outside of module root". This must be identified during this traversal instead of during AstGen, because it depends on which module the file is in. I tried also representing "module not found" errors in this same way, but it turns out to be much more useful to report those in Sema, because of use cases like optional dependencies where a module import is behind a comptime-known build option. For simplicity, `failed_files` now just maps to `?[]u8`, since the source location is always the whole file. In fact, this allows removing `LazySrcLoc.Offset.entire_file` completely, slightly simplifying some error reporting logic. File-level errors are now directly built in the `std.zig.ErrorBundle.Wip`. If the payload is not `null`, it is the message for a retryable error (i.e. an error loading the source file), and will be reported with a "file imported here" note pointing to the import site discovered during the single-threaded file traversal. The last piece of fallout here is how `Builtin` works. Rather than constructing "builtin" modules when creating `Package.Module`s, they are now constructed on-the-fly by `Zcu`. The map `Zcu.builtin_modules` maps from digests to `*Package.Module`s. These digests are abstract hashes of the `Builtin` value; i.e. all of the options which are placed into "builtin.zig". During the file traversal, we populate `builtin_modules` as needed, so that when we see this imports in Sema, we just grab the relevant entry from this map. This eliminates a bunch of awkward state tracking during construction of the module graph. It's also now clearer exactly what options the builtin module has, since previously it inherited some options arbitrarily from the first-created module with that "builtin" module! The user-visible effects of this commit are: * retryable file errors are now consistently reported against the whole file, with a note pointing to a live import of that file * some theoretical bugs where imports are wrongly considered distinct (when the import path moves out of the cwd and then back in) are fixed * some consistency issues with how file-level errors are reported are fixed; these errors will now always be printed in the same order regardless of how the AstGen pass assigns file indices * incremental updates do not print retryable file errors differently between updates or depending on file structure/contents * incremental updates support files changing modules * incremental updates support files becoming unreferenced Resolves: #22696
2025-04-13link: Improve handling of --build-id when using LLD.Alex Rønne Petersen
2025-04-11Introduce libzigc for libc function implementations in Zig.Alex Rønne Petersen
This lays the groundwork for #2879. This library will be built and linked when a static libc is going to be linked into the compilation. Currently, that means musl, wasi-libc, and MinGW-w64. As a demonstration, this commit removes the musl C code for a few string functions and implements them in libzigc. This means that those libzigc functions are now load-bearing for musl and wasi-libc. Note that if a function has an implementation in compiler-rt already, libzigc should not implement it. Instead, as we recently did for memcpy/memmove, we should delete the libc copy and rely on the compiler-rt implementation. I repurposed the existing "universal libc" code to do this. That code hadn't seen development beyond basic string functions in years, and was only usable-ish on freestanding. I think that if we want to seriously pursue the idea of Zig providing a freestanding libc, we should do so only after defining clear goals (and non-goals) for it. See also #22240 for a similar case.
2025-03-27std.meta.FieldType -> @FieldTypeАндрей Краевский
2025-03-23codegen: fix packed byte-aligned relocationsJacob Young
Closes #23131
2025-03-18mingw: Rename mingw32.lib to libmingw32.lib.Alex Rønne Petersen
LLD expects the library file name (minus extension) to be exactly libmingw32. By calling it mingw32 previously, we prevented it from being detected as being in LLD's list of libraries that are excluded from the MinGW-specific auto-export mechanism. https://github.com/llvm/llvm-project/blob/b9d27ac252265839354fffeacaa8f39377ed7424/lld/COFF/MinGW.cpp#L30-L56 As a result, a DLL built for *-windows-gnu with Zig would export a bunch of internal MinGW symbols. This sometimes worked out fine, but it could break at link or run time when linking an EXE with a DLL, where both are targeting *-windows-gnu and thus linking separate copies of mingw32.lib. In #23204, this manifested as the linker getting confused about _gnu_exception_handler() because it was incorrectly exported by the DLL while also being defined in the mingw32.lib that was being linked into the EXE. Closes #23204.
2025-02-25move libubsan to `lib/` and integrate it into `-fubsan-rt`David Rubin
2025-02-22zig build fmtAndrew Kelley
2025-02-17std.Target: Remove functions that just wrap component functions.Alex Rønne Petersen
Functions like isMinGW() and isGnuLibC() have a good reason to exist: They look at multiple components of the target. But functions like isWasm(), isDarwin(), isGnu(), etc only exist to save 4-8 characters. I don't think this is a good enough reason to keep them, especially given that: * It's not immediately obvious to a reader whether target.isDarwin() means the same thing as target.os.tag.isDarwin() precisely because isMinGW() and similar functions *do* look at multiple components. * It's not clear where we would draw the line. The logical conclusion before this commit would be to also wrap Arch.isX86(), Os.Tag.isSolarish(), Abi.isOpenHarmony(), etc... this obviously quickly gets out of hand. * It's nice to just have a single correct way of doing something.
2025-02-10std.ArrayList: popOrNull() -> pop() [v2] (#22720)Meghan Denny
2025-02-07std.ArrayHashMap: popOrNul() -> pop()Meghan Denny
2025-01-25link: Set machine and float ABI when invoking ld.lld and lld-link.Alex Rønne Petersen
If this isn't done, LTO can completely miscompile the input bitcode modules for certain targets where we need to explicitly set these ABIs (because LLVM's defaults are bad).
2025-01-15fix compilation when enabling llvmAndrew Kelley
2025-01-15switch to ArrayListUnmanaged for machine codeAndrew Kelley
2025-01-15rewrite wasm/Emit.zigAndrew Kelley
mainly, rework how relocations works. This is the point at which symbol indexes are known - not before. And don't emit unnecessary relocations! They're only needed when emitting an object file. Changes wasm linker to keep MIR around long-lived so that fixups can be reapplied after linker garbage collection. use labeled switch while we're at it
2025-01-15rework error handling in the backendsAndrew Kelley
2025-01-15macho linker: conform to explicit error setsAndrew Kelley
Makes linker functions have small error sets, required to report diagnostics properly rather than having a massive error set that has a lot of codes. Other linker implementations are not ported yet. Also the branch is not passing semantic analysis yet.