This PR unifies the terminology for:
* "context hash" - previously ambiguously referred to as "module hash"
or as overly specific "module context hash"
* "specific module cache path" - previously referred to as just "module
cache path" - hard to distinguish from the command-line-provided module
cache path without the context hash
NFCI
The `ModuleCache` class is currently reference-counted intrusively. As
explained in https://github.com/llvm/llvm-project/pull/139584, this is
problematic. This PR uses `std::shared_ptr` to reference-count
`ModuleCache` instead, which clarifies what happens to its lifetime when
constructing `CompilerInstance`, for example. This also makes the
reference in `ModuleManager` non-owning, simplifying the ownership
relationship further. The
`ASTUnit::transferASTDataFromCompilerInstance()` function now accounts
for that by taking care to keep it alive.
This relands #165277 by reverting #169397.
This also relands the corresponding Bazel port by reverting #169410.
The original revert was due to a report of a broken build, which was
later resolved by fully clearing the build directory.
This removes the dependency on clangDriver from clangFrontend and
flangFrontend.
This refactoring is part of a broader effort to support driver-managed
builds for compilations using C++ named modules and/or Clang modules.
It is required for linking the dependency scanning tooling against the
driver without introducing cyclic dependencies, which would otherwise
cause build failures when dynamic linking is enabled.
In particular, clangFrontend must no longer depend on clangDriver
for this to be possible.
This change was discussed in the following RFC:
https://discourse.llvm.org/t/rfc-new-clangoptions-library-remove-dependency-on-clangdriver-from-clangfrontend-and-flangfrontend/88773
d076608d58d1ec55016eb747a995511e3a3f72aa moved some deps around to avoid
cycles and left clang/Frontend/FrontendDiagnostic.h as a shim that
simply includes clang/Basic/DiagnosticFrontend.h. This PR inlines it so
that nothing in tree still includes clang/Frontend/FrontendDiagnostic.h.
Doing this will help prevent future layering issues. See #162865.
Frontend already depends on Basic, so no new deps need to be added
anywhere except for places that do strict dep checking.
This implements the parts of
https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3457.htm which were
adopted at the recent meeting in Brno.
Clang already implemented `__COUNTER__`, but needed some changes for
conformance. Specifically, we now diagnose when the macro is expanded
more than 2147483647 times. Additionally, we now give the expected
extension and pre-compat warnings for the feature.
To support testing the limits, this also adds a -cc1-only option,
`-finitial-counter-value=`, which lets you specify the initial value the
`__COUNTER__` macro should expand to.
This PR refactors `ASTUnit::LoadFromASTFile()` to be easier to follow.
Conceptually, it tries to read an AST file, adopt the serialized
options, and set up `Sema` and `ASTContext` to deserialize the AST file
contents on-demand.
The implementation of this used to be spread across an
`ASTReaderListener` and the function in question. Figuring out what
listener method gets called when and how it's supposed to interact with
the rest of the functionality was very unclear. The `FileManager`'s VFS
was being swapped-out during deserialization, the options were being
adopted by `Preprocessor` and others just-in-time to pass `ASTReader`'s
validation checks, and the target was being initialized somewhere in
between all of this. This lead to a very muddy semantics.
This PR splits `ASTUnit::LoadFromASTFile()` into three distinct steps:
1. Read out the options from the AST file.
2. Initialize objects from the VFS to the `ASTContext`.
3. Load the AST file and hook it up with the compiler objects.
This should be much easier to understand, and I've done my best to
clearly document the remaining gotchas.
(This was originally motivated by the desire to remove
`FileManager::setVirtualFileSystem()` and make it impossible to swap out
VFSs from underneath `FileManager` mid-compile.)
Since https://github.com/llvm/llvm-project/pull/158381 the
`CompilerInstance` is aware of the VFS and co-owns it. To reduce scope
of that PR, the VFS was being inherited from the `FileManager` during
`setFileManager()` if it wasn't configured before. However, the
implementation of that setter was buggy. This PR fixes the bug, and
moves us closer to the long-term goal of `CompilerInstance` requiring
the VFS to be configured explicitly and owned by the instance.
This PR makes the `VFS` parameter to `ASTUnit::LoadFromASTFile()`
required and explicit, rather than silently defaulting to the real file
system. This makes it easy to correctly propagate the fully-configured
VFS and load any input files like the rest of the compiler does.
This PR is a part of the effort to make the VFS used in the compiler
more explicit and consistent.
Instead of creating the VFS deep within the compiler (in
`CompilerInstance::createFileManager()`), clients are now required to
explicitly call `CompilerInstance::createVirtualFileSystem()` and
provide the base VFS from the outside.
This PR also helps in breaking up the dependency cycle where creating a
properly configured `DiagnosticsEngine` requires a properly configured
VFS, but creating properly configuring a VFS requires the
`DiagnosticsEngine`.
Both `CompilerInstance::create{FileManager,Diagnostics}()` now just use
the VFS already in `CompilerInstance` instead of taking one as a
parameter, making the VFS consistent across the instance sub-object.
This reintroduces `Type.h`, having earlier been renamed to `TypeBase.h`,
as a redirection to `TypeBase.h`, and redirects most users to include
the former instead.
This is a preparatory patch for being able to provide inline definitions
for `Type` methods which would otherwise cause a circular dependency
with `Decl{,CXX}.h`.
Doing these operations into their own NFC patch helps the git rename
detection logic work, preserving the history.
This patch makes clang just a little slower to build (~0.17%), just
because it makes more code indirectly include `DeclCXX.h`.
This is a preparatory patch, to be able to provide inline definitions
for `Type` functions which depend on `Decl{,CXX}.h`. As the latter also
depends on `Type.h`, this would not be possible without some
reorganizing.
Splitting this rename into its own patch allows git to track this as a
rename, and preserve all git history, and not force any code
reformatting.
A later NFC patch will reintroduce `Type.h` as redirection to
`TypeBase.h`, rewriting most places back to directly including `Type.h`
instead of `TypeBase.h`, leaving only a handful of places where this is
necessary.
Then yet a later patch will exploit this by making more stuff inline.
This is a major change on how we represent nested name qualifications in
the AST.
* The nested name specifier itself and how it's stored is changed. The
prefixes for types are handled within the type hierarchy, which makes
canonicalization for them super cheap, no memory allocation required.
Also translating a type into nested name specifier form becomes a no-op.
An identifier is stored as a DependentNameType. The nested name
specifier gains a lightweight handle class, to be used instead of
passing around pointers, which is similar to what is implemented for
TemplateName. There is still one free bit available, and this handle can
be used within a PointerUnion and PointerIntPair, which should keep
bit-packing aficionados happy.
* The ElaboratedType node is removed, all type nodes in which it could
previously apply to can now store the elaborated keyword and name
qualifier, tail allocating when present.
* TagTypes can now point to the exact declaration found when producing
these, as opposed to the previous situation of there only existing one
TagType per entity. This increases the amount of type sugar retained,
and can have several applications, for example in tracking module
ownership, and other tools which care about source file origins, such as
IWYU. These TagTypes are lazily allocated, in order to limit the
increase in AST size.
This patch offers a great performance benefit.
It greatly improves compilation time for
[stdexec](https://github.com/NVIDIA/stdexec). For one datapoint, for
`test_on2.cpp` in that project, which is the slowest compiling test,
this patch improves `-c` compilation time by about 7.2%, with the
`-fsyntax-only` improvement being at ~12%.
This has great results on compile-time-tracker as well:
This patch also further enables other optimziations in the future, and
will reduce the performance impact of template specialization resugaring
when that lands.
It has some other miscelaneous drive-by fixes.
About the review: Yes the patch is huge, sorry about that. Part of the
reason is that I started by the nested name specifier part, before the
ElaboratedType part, but that had a huge performance downside, as
ElaboratedType is a big performance hog. I didn't have the steam to go
back and change the patch after the fact.
There is also a lot of internal API changes, and it made sense to remove
ElaboratedType in one go, versus removing it from one type at a time, as
that would present much more churn to the users. Also, the nested name
specifier having a different API avoids missing changes related to how
prefixes work now, which could make existing code compile but not work.
How to review: The important changes are all in
`clang/include/clang/AST` and `clang/lib/AST`, with also important
changes in `clang/lib/Sema/TreeTransform.h`.
The rest and bulk of the changes are mostly consequences of the changes
in API.
PS: TagType::getDecl is renamed to `getOriginalDecl` in this patch, just
for easier to rebasing. I plan to rename it back after this lands.
Fixes#136624
Fixes https://github.com/llvm/llvm-project/issues/43179
Fixes https://github.com/llvm/llvm-project/issues/68670
Fixes https://github.com/llvm/llvm-project/issues/92757
This commit handles the following types:
- clang::ExternalASTSource
- clang::TargetInfo
- clang::ASTContext
- clang::SourceManager
- clang::FileManager
Part of cleanup #151026
Handles clang::DiagnosticsEngine and clang::DiagnosticIDs.
For DiagnosticIDs, this mostly migrates from `new DiagnosticIDs` to
convenience method `DiagnosticIDs::create()`.
Part of cleanup https://github.com/llvm/llvm-project/issues/151026
This switches to `makeIntrusiveRefCnt<FileSystem>` where creating a new
object, and to passing/returning by `IntrusiveRefCntPtr<FileSystem>`
instead of `FileSystem*` or `FileSystem&`, when dealing with existing
objects.
Part of cleanup #151026.
Some `LangOptions` duplicate their `CodeGenOptions` counterparts. My
understanding is that this was done solely because some infrastructure
(like preprocessor initialization, serialization, module compatibility
checks, etc.) were only possible/convenient for `LangOptions`. This PR
implements the missing support for `CodeGenOptions`, which makes it
possible to remove some duplicate `LangOptions` fields and simplify the
logic. Motivated by https://github.com/llvm/llvm-project/pull/146342.
This patch fixes an issue where Microsoft-specific layout attributes,
such as __declspec(empty_bases), were ignored during CUDA/HIP device
compilation on a Windows host. This caused a critical memory layout
mismatch between host and device objects, breaking libraries that rely
on these attributes for ABI compatibility.
The fix introduces a centralized hasMicrosoftRecordLayout() check within
the TargetInfo class. This check is aware of the auxiliary (host) target
and is set during TargetInfo::adjust if the host uses a Microsoft ABI.
The empty_bases, layout_version, and msvc::no_unique_address attributes
now use this centralized flag, ensuring device code respects them and
maintains layout consistency with the host.
Fixes: https://github.com/llvm/llvm-project/issues/146047
These are identified by misc-include-cleaner. I've filtered out those
that break builds. Also, I'm staying away from llvm-config.h,
config.h, and Compiler.h, which likely cause platform- or
compiler-specific build failures.
This reverts commit e2a885537f11f8d9ced1c80c2c90069ab5adeb1d. Build failures were fixed right away and reverting the original commit without the fixes breaks the build again.
The `DiagnosticOptions` class is currently intrusively
reference-counted, which makes reasoning about its lifetime very
difficult in some cases. For example, `CompilerInvocation` owns the
`DiagnosticOptions` instance (wrapped in `llvm::IntrusiveRefCntPtr`) and
only exposes an accessor returning `DiagnosticOptions &`. One would
think this gives `CompilerInvocation` exclusive ownership of the object,
but that's not the case:
```c++
void shareOwnership(CompilerInvocation &CI) {
llvm::IntrusiveRefCntPtr<DiagnosticOptions> CoOwner = &CI.getDiagnosticOptions();
// ...
}
```
This is a perfectly valid pattern that is being actually used in the
codebase.
I would like to ensure the ownership of `DiagnosticOptions` by
`CompilerInvocation` is guaranteed to be exclusive. This can be
leveraged for a copy-on-write optimization later on. This PR changes
usages of `DiagnosticOptions` across `clang`, `clang-tools-extra` and
`lldb` to not be intrusively reference-counted.
This reverts commit 7a242387c950c7060143da6da0e6fb91f36bb458. Even after 175f8a44, the Modules/fmodules-validate-once-per-build-session.c test is not fixed on the clang-armv8-quick build bot. (Failure occurs on line 114.)
This reverts commit 18b885f66babff3a10451bc811ffc077d61ed8ee, effectively reapplying #139987. This commit fixes unit tests (for example ASTUnitTest.SaveLoadPreservesLangOptionsInPrintingPolicy) where the `ASTUnit::ModCache` pointer dereferenced within `ASTUnit::serialize()` was null. This commit makes sure each factory function does initialize `ASTUnit::ModCache`.
Timestamps are an implementation detail of the cross-process module
cache implementation. This PR hides it from the `ModuleCache` API, which
simplifies the in-process implementation.
This PR makes it so that `CompilerInvocation` needs to be provided to
`CompilerInstance` on construction. There are a couple of benefits in my
view:
* Making it impossible to mis-use some `CompilerInstance` APIs. For
example there are cases, where `createDiagnostics()` was called before
`setInvocation()`, causing the `DiagnosticEngine` to use the
default-constructed `DiagnosticOptions` instead of the intended ones.
* This shrinks `CompilerInstance`'s state space.
* This makes it possible to access **the** invocation in
`CompilerInstance`'s constructor (to be used in a follow-up).
This PR hides the reference-counted pointer that holds `TargetOptions`
from the public API of `CompilerInvocation`. This gives
`CompilerInvocation` an exclusive control over the lifetime of this
member, which will eventually be leveraged to implement a copy-on-write
behavior.
There are two clients that currently share ownership of that pointer:
* `TargetInfo` - This was refactored to hold a non-owning reference to
`TargetOptions`. The options object is typically owned by the
`CompilerInvocation` or by the new `CompilerInstance::AuxTargetOpts` for
the auxiliary target. This needed a bit of care in `ASTUnit::Parse()` to
keep the `CompilerInvocation` alive.
* `clangd::PreambleData` - This was refactored to exclusively own the
`TargetOptions` that get moved out of the `CompilerInvocation`.
This makes it so that `CompilerInvocation` can be the only entity that
manages ownership of `HeaderSearchOptions`, making it possible to
implement copy-on-write semantics.
This PR adds new `ModuleCache` interface to Clang's implicitly-built
modules machinery. The main motivation for this change is to create a
second implementation that uses a more efficient kind of
`llvm::AdvisoryLock` during dependency scanning.
In addition to the lock abstraction, the `ModuleCache` interface also
manages the existing `InMemoryModuleCache` instance. I found that
compared to keeping these separate/independent, the code is a bit
simpler now, since these are two tightly coupled concepts. I can
envision a more efficient implementation of the `InMemoryModuleCache`
for the single-process case too, which will be much easier to implement
with the current setup.
This is not intended to be a functional change.
This implements
https://discourse.llvm.org/t/rfc-add-support-for-controlling-diagnostics-severities-at-file-level-granularity-through-command-line/81292.
Users now can suppress warnings for certain headers by providing a
mapping with globs, a sample file looks like:
```
[unused]
src:*
src:*clang/*=emit
```
This will suppress warnings from `-Wunused` group in all files that
aren't under `clang/` directory. This mapping file can be passed to
clang via `--warning-suppression-mappings=foo.txt`.
At a high level, mapping file is stored in DiagnosticOptions and then
processed with rest of the warning flags when creating a
DiagnosticsEngine. This is a functor that uses SpecialCaseLists
underneath to match against globs coming from the mappings file.
This implies processing warning options now performs IO, relevant
interfaces are updated to take in a VFS, falling back to RealFileSystem
when one is not available.
This PR builds on top of
https://github.com/llvm/llvm-project/pull/115235 and makes it possible
to call `ASTWriter::WriteAST()` with `Preprocessor` only instead of full
`Sema` object. So far, there are no clients that leverage the new
capability - that will come in a follow-up commit.
Some `FileManager` APIs still return `{File,Directory}Entry` instead of
the preferred `{File,Directory}EntryRef`. These are documented to be
deprecated, but don't have the attribute that warns on their usage. This
PR marks them as such with `LLVM_DEPRECATED()` and replaces their usage
with the recommended counterparts. NFCI.
Without this patch, several callers of LoadFromASTFile construct an
instance of std::string to be passed as FileName, only to be converted
back to StringRef when LoadFromASTFile calls ReadAST.
This patch changes the type of FileName to StringRef and updates the
callers.
Claiming a mismatch is always in a precompiled header is wrong and
misleading as a mismatch can happen in any provided AST file. Emitting a
path for a file with a problem allows to disambiguate between multiple
input files.
Use generic term "AST file" because we don't always know a kind of the
provided file (for example, see `ASTReader::readASTFileControlBlock`).
rdar://65005546
Now we can create a LocalDeclID directly with an integer without
verifying. It may be hard to refactor if we want to change the way we
serialize DeclIDs (See https://github.com/llvm/llvm-project/pull/95897).
Also it is hard for us to debug if someday someone construct a
LocalDeclID with an incorrect value.
So in this patch, I tried to unify the way we can construct a
LocalDeclID in ASTReader, where we will construct the LocalDeclID from
the serialized data. Also, now we can verify the constructed LocalDeclID
sooner in the new interface.
