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2025-09-30fix compiler ftbfs from std.macho and std.dwarf changesmlugg
2025-09-21Elf2: create a new linker from scratchJacob Young
This iteration already has significantly better incremental support. Closes #24110
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
2025-08-15Dwarf: implement comptime-known extern valuesJacob Young
Closes #24259
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`
2025-08-11linker: delete plan9 supportAndrew Kelley
This experimental target was never fully completed. The operating system is not that interesting or popular anyway, and the maintainer is no longer around. Not worth the maintenance burden. This code can be resurrected later if it is worth it. In such case it will be subject to greater scrutiny.
2025-07-22aarch64: add new from scratch self-hosted backendJacob Young
2025-07-07MachO: revert unfinished changesAndrew Kelley
2025-07-07MachO: update to new std.io APIsAndrew 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
2025-06-19Target: 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.
2025-06-12codegen: make threadlocal logic consistentJacob Young
2025-06-12x86_64: remove linker references from codegenJacob Young
2025-06-12x86_64: remove air references from mirJacob Young
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.
2025-06-12link: 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.
2025-05-29Legalize: 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
2025-02-22zig build fmtAndrew Kelley
2025-02-22link.MachO: Add support for the -x flag (discard local symbols).Alex Rønne Petersen
This can also be extended to ELF later as it means roughly the same thing there. This addresses the main issue in #21721 but as I don't have a macOS machine to do further testing on, I can't confirm whether zig cc is able to pass the entire cgo test suite after this commit. It can, however, cross-compile a basic program that uses cgo to x86_64-macos-none which previously failed due to lack of -x support. Unlike previously, the resulting symbol table does not contain local symbols (such as C static functions). I believe this satisfies the related donor bounty: https://ziglang.org/news/second-donor-bounty
2025-01-15fix merge conflicts with updating line numbersAndrew 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
2025-01-15compiler: add type safety for export indicesAndrew Kelley
2025-01-15rework error handling in the backendsAndrew Kelley
2025-01-15macho linker conforms to explicit error sets, againAndrew 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.
2025-01-15wasm linker: aggressive DODificationAndrew Kelley
The goals of this branch are to: * compile faster when using the wasm linker and backend * enable saving compiler state by directly copying in-memory linker state to disk. * more efficient compiler memory utilization * introduce integer type safety to wasm linker code * generate better WebAssembly code * fully participate in incremental compilation * do as much work as possible outside of flush(), while continuing to do linker garbage collection. * avoid unnecessary heap allocations * avoid unnecessary indirect function calls In order to accomplish this goals, this removes the ZigObject abstraction, as well as Symbol and Atom. These abstractions resulted in overly generic code, doing unnecessary work, and needless complications that simply go away by creating a better in-memory data model and emitting more things lazily. For example, this makes wasm codegen emit MIR which is then lowered to wasm code during linking, with optimal function indexes etc, or relocations are emitted if outputting an object. Previously, this would always emit relocations, which are fully unnecessary when emitting an executable, and required all function calls to use the maximum size LEB encoding. This branch introduces the concept of the "prelink" phase which occurs after all object files have been parsed, but before any Zcu updates are sent to the linker. This allows the linker to fully parse all objects into a compact memory model, which is guaranteed to be complete when Zcu code is generated. This commit is not a complete implementation of all these goals; it is not even passing semantic analysis.
2025-01-05Dwarf: implement new incremental line number update APIJacob Young
2025-01-05link: new incremental line number update APImlugg
2024-12-24compiler: analyze type and value of global declaration separatelymlugg
This commit separates semantic analysis of the annotated type vs value of a global declaration, therefore allowing recursive and mutually recursive values to be declared. Every `Nav` which undergoes analysis now has *two* corresponding `AnalUnit`s: `.{ .nav_val = n }` and `.{ .nav_ty = n }`. The `nav_val` unit is responsible for *fully resolving* the `Nav`: determining its value, linksection, addrspace, etc. The `nav_ty` unit, on the other hand, resolves only the information necessary to construct a *pointer* to the `Nav`: its type, addrspace, etc. (It does also analyze its linksection, but that could be moved to `nav_val` I think; it doesn't make any difference). Analyzing a `nav_ty` for a declaration with no type annotation will just mark a dependency on the `nav_val`, analyze it, and finish. Conversely, analyzing a `nav_val` for a declaration *with* a type annotation will first mark a dependency on the `nav_ty` and analyze it, using this as the result type when evaluating the value body. The `nav_val` and `nav_ty` units always have references to one another: so, if a `Nav`'s type is referenced, its value implicitly is too, and vice versa. However, these dependencies are trivial, so, to save memory, are only known implicitly by logic in `resolveReferences`. In general, analyzing ZIR `decl_val` will only analyze `nav_ty` of the corresponding `Nav`. There are two exceptions to this. If the declaration is an `extern` declaration, then we immediately ensure the `Nav` value is resolved (which doesn't actually require any more analysis, since such a declaration has no value body anyway). Additionally, if the resolved type has type tag `.@"fn"`, we again immediately resolve the `Nav` value. The latter restriction is in place for two reasons: * Functions are special, in that their externs are allowed to trivially alias; i.e. with a declaration `extern fn foo(...)`, you can write `const bar = foo;`. This is not allowed for non-function externs, and it means that function types are the only place where it is possible for a declaration `Nav` to have a `.@"extern"` value without actually being declared `extern`. We need to identify this situation immediately so that the `decl_ref` can create a pointer to the *real* extern `Nav`, not this alias. * In certain situations, such as taking a pointer to a `Nav`, Sema needs to queue analysis of a runtime function if the value is a function. To do this, the function value needs to be known, so we need to resolve the value immediately upon `&foo` where `foo` is a function. This restriction is simple to codify into the eventual language specification, and doesn't limit the utility of this feature in practice. A consequence of this commit is that codegen and linking logic needs to be more careful when looking at `Nav`s. In general: * When `updateNav` or `updateFunc` is called, it is safe to assume that the `Nav` being updated (the owner `Nav` for `updateFunc`) is fully resolved. * Any `Nav` whose value is/will be an `@"extern"` or a function is fully resolved; see `Nav.getExtern` for a helper for a common case here. * Any other `Nav` may only have its type resolved. This didn't seem to be too tricky to satisfy in any of the existing codegen/linker backends. Resolves: #131
2024-12-20lldb: add pretty printer for intern pool indicesJacob Young
2024-10-20link: Use defaultFunctionAlignment() when function alignment is unspecified.Alex Rønne Petersen
max(user_align, minFunctionAlignment()) is only appropriate when the user has actually given an explicit, non-zero alignment value.
2024-10-11link: consolidate diagnosticsAndrew Kelley
By organizing linker diagnostics into this struct, it becomes possible to share more code between linker backends, and more importantly it becomes possible to pass only the Diag struct to some functions, rather than passing the entire linker state object in. This makes data dependencies more obvious, making it easier to rearrange code and to multithread. Also fix MachO code abusing an atomic variable. Not only was it using the wrong atomic operation, it is unnecessary additional state since the state is already being protected by a mutex.
2024-10-10link: fix false positive crtbegin/crtend detectionAndrew Kelley
Embrace the Path abstraction, doing more operations based on directory handles rather than absolute file paths. Most of the diff noise here comes from this one. Fix sorting of crtbegin/crtend atoms. Previously it would look at all path components for those strings. Make the C runtime path detection partially a pure function, and move some logic to glibc.zig where it belongs.
2024-09-12Replace deprecated default initializations with decl literalsLinus Groh
2024-09-10codegen: implement output to the `.debug_info` sectionJacob Young
2024-08-28std: update `std.builtin.Type` fields to follow naming conventionsmlugg
The compiler actually doesn't need any functional changes for this: Sema does reification based on the tag indices of `std.builtin.Type` already! So, no zig1.wasm update is necessary. This change is necessary to disallow name clashes between fields and decls on a type, which is a prerequisite of #9938.
2024-08-25fix up merge conflicts with masterDavid Rubin
2024-08-25remove `mod` aliases for ZcusDavid Rubin
2024-08-25comp: rename `module` to `zcu`David Rubin
2024-08-25sema: rework type resolution to use Zcu when possibleDavid Rubin
2024-08-20Dwarf: fix issues with inline call sitesJacob Young
2024-08-17macho: update codegen and linker to distributed jump table approachJakub Konka
2024-08-16Dwarf: rework self-hosted debug info from scratchJacob Young
This is in preparation for incremental and actually being able to debug executables built by the x86_64 backend.
2024-08-11compiler: split Decl into Nav and Caumlugg
The type `Zcu.Decl` in the compiler is problematic: over time it has gained many responsibilities. Every source declaration, container type, generic instantiation, and `@extern` has a `Decl`. The functions of these `Decl`s are in some cases entirely disjoint. After careful analysis, I determined that the two main responsibilities of `Decl` are as follows: * A `Decl` acts as the "subject" of semantic analysis at comptime. A single unit of analysis is either a runtime function body, or a `Decl`. It registers incremental dependencies, tracks analysis errors, etc. * A `Decl` acts as a "global variable": a pointer to it is consistent, and it may be lowered to a specific symbol by the codegen backend. This commit eliminates `Decl` and introduces new types to model these responsibilities: `Cau` (Comptime Analysis Unit) and `Nav` (Named Addressable Value). Every source declaration, and every container type requiring resolution (so *not* including `opaque`), has a `Cau`. For a source declaration, this `Cau` performs the resolution of its value. (When #131 is implemented, it is unsolved whether type and value resolution will share a `Cau` or have two distinct `Cau`s.) For a type, this `Cau` is the context in which type resolution occurs. Every non-`comptime` source declaration, every generic instantiation, and every distinct `extern` has a `Nav`. These are sent to codegen/link: the backends by definition do not care about `Cau`s. This commit has some minor technically-breaking changes surrounding `usingnamespace`. I don't think they'll impact anyone, since the changes are fixes around semantics which were previously inconsistent (the behavior changed depending on hashmap iteration order!). Aside from that, this changeset has no significant user-facing changes. Instead, it is an internal refactor which makes it easier to correctly model the responsibilities of different objects, particularly regarding incremental compilation. The performance impact should be negligible, but I will take measurements before merging this work into `master`. Co-authored-by: Jacob Young <jacobly0@users.noreply.github.com> Co-authored-by: Jakub Konka <kubkon@jakubkonka.com>
2024-08-10MachO/ZigObject: handle ref to an extern in getDeclVAddrJakub Konka