1723 Commits

Author SHA1 Message Date
Michael Spencer
7847e44594
[clang][DependencyScanner] Remove unused -ivfsoverlay files (#73734)
`-ivfsoverlay` files are unused when building most modules. Enable
removing them by,
* adding a way to visit the filesystem tree with extensible RTTI to
  access each `RedirectingFileSystem`.
* Adding tracking to `RedirectingFileSystem` to record when it
  actually redirects a file access.
* Storing this information in each PCM.

Usage tracking is only enabled when iterating over the source manager
and affecting modulemaps. Here each path is stated to cause an access.
During scanning these stats all hit the cache.
2024-01-30 15:39:18 -08:00
Chuanqi Xu
a0b6747804 [C++20] [Modules] Don't perform ODR checks in GMF
Close https://github.com/llvm/llvm-project/issues/79240.

See the linked issue for details. Given the frequency of issue reporting
about false positive ODR checks (I received private issue reports too),
I'd like to backport this to 18.x too.
2024-01-29 11:44:59 +08:00
cor3ntin
ad1a65fcac
[Clang][C++26] Implement Pack Indexing (P2662R3). (#72644)
Implements https://isocpp.org/files/papers/P2662R3.pdf

The feature is exposed as an extension in older language modes.
Mangling is not yet supported and that is something we will have to do before release.
2024-01-27 10:23:38 +01:00
Chuanqi Xu
ba1e84fb8f [C++20] [Modules] Handle inconsistent deduced function return type from importing modules
Close https://github.com/llvm/llvm-project/issues/78830
Close https://github.com/llvm/llvm-project/issues/60085

The direct reason of the issues is that in a module unit, the return
type of a function is deduced to a concrete type (e.g., int) but in the
other module unit, the return type of the same function is not deduced
yet (e.g, auto). Then when we importing the 2 modules, the later
function is selected but the code generator doesn't know how to generate
the auto type. So here is the crash.

The tricky part here is that, when the ASTReader reads the second
unreduced function, it finds the reading function has the same signature
with the already read deduced one and they have the same ODRHash. So
that the ASTReader skips loading the function body of the unreduced
function then the code generator can't infer the undeduced type like it
usually can. Also this is generally fine for functions without deducing
type since it is sufficient to emit a function call without the function
body.

Also in fact, we've already handled the case that the functon has
deduced type and its deducing state is inconsist in different modules:
3ea92ea2f9/clang/lib/Serialization/ASTReader.cpp (L9531-L9544)
and
3ea92ea2f9/clang/lib/Serialization/ASTReaderDecl.cpp (L3643-L3647).

We've handled the case:
(1) If we read the undeduced functions first and read the deduced functions
later, the compiler will propagate the deduced type info for redecls in
the end of the reading.
(2) If we read the deduced functions first and read the undeduced
functions later, we will propagae the deduced type info when we **complete
the redecl chain**.

However, in the reporting issues, we're in the second case and
reproducer didn't trigger the action to complete the redecl chain. So
here is the crash.

Then it is obvious how should fix the problem. We should complete the
redecl chain for undeduced function types in the end of the reading for
the second case.
2024-01-23 16:19:51 +08:00
Andrey Ali Khan Bolshakov
5518a9d767
[c++20] P1907R1: Support for generalized non-type template arguments of scalar type. (#78041)
Previously committed as 9e08e51a20d0d2b1c5724bb17e969d036fced4cd, and
reverted because a dependency commit was reverted, then committed again
as 4b574008aef5a7235c1f894ab065fe300d26e786 and reverted again because
"dependency commit" 5a391d38ac6c561ba908334d427f26124ed9132e was
reverted. But it doesn't seem that 5a391d38ac6c was a real dependency
for this.

This commit incorporates 4b574008aef5a7235c1f894ab065fe300d26e786 and
18e093faf726d15f210ab4917142beec51848258 by Richard Smith (@zygoloid),
with some minor fixes, most notably:

- `UncommonValue` renamed to `StructuralValue`

- `VK_PRValue` instead of `VK_RValue` as default kind in lvalue and
member pointer handling branch in
`BuildExpressionFromNonTypeTemplateArgumentValue`;

- handling of `StructuralValue` in `IsTypeDeclaredInsideVisitor`;

- filling in `SugaredConverted` along with `CanonicalConverted`
parameter in `Sema::CheckTemplateArgument`;

- minor cleanup in
`TemplateInstantiator::transformNonTypeTemplateParmRef`;

- `TemplateArgument` constructors refactored;

- `ODRHash` calculation for `UncommonValue`;

- USR generation for `UncommonValue`;

- more correct MS compatibility mangling algorithm (tested on MSVC ver.
19.35; toolset ver. 143);

- IR emitting fixed on using a subobject as a template argument when the
corresponding template parameter is used in an lvalue context;

- `noundef` attribute and opaque pointers in `template-arguments` test;

- analysis for C++17 mode is turned off for templates in
`warn-bool-conversion` test; in C++17 and C++20 mode, array reference
used as a template argument of pointer type produces template argument
of UncommonValue type, and
`BuildExpressionFromNonTypeTemplateArgumentValue` makes
`OpaqueValueExpr` for it, and `DiagnoseAlwaysNonNullPointer` cannot see
through it; despite of "These cases should not warn" comment, I'm not
sure about correct behavior; I'd expect a suggestion to replace `if` by
`if constexpr`;

- `temp.arg.nontype/p1.cpp` and `dr18xx.cpp` tests fixed.
2024-01-21 21:28:57 +01:00
Chuanqi Xu
dc4e85bd79 [C++20] [Modules] Remove hardcoded path to imported module in BMIs
Close https://github.com/llvm/llvm-project/issues/62707

As we discussed before, we'll forbid the use of implicit generated path
for C++20 modules. And as I mentioned in
https://github.com/llvm/llvm-project/issues/62707, we've emitted a
warning for clang17 and we'll make it a hard error in clang18. And the
patch addresses the decision.
2024-01-12 13:47:59 +08:00
Fangrui Song
9950bb9944 [ASTReader] Fix readability-inconsistent-declaration-parameter-name. NFC 2023-12-15 17:11:21 -08:00
Jan Svoboda
cb92511c4d
[clang] NFC: Remove OptionalDirectoryEntryRefDegradesToDirectoryEntryPtr (#74900) 2023-12-08 18:22:53 -08:00
Jan Svoboda
0cb0a48cde
[clang] NFC: Remove OptionalFileEntryRefDegradesToFileEntryPtr (#74899) 2023-12-08 18:22:41 -08:00
Jan Svoboda
8615ead9a6
[clang] NFCI: Make ModuleFile::File non-optional (#74892)
AFAICT, `ModuleFile::File` can be `std::nullopt` only for PCM files
loaded from the standard input. This patch starts setting that variable
to `FileManager::getSTDIN()` in that case, which makes it possible to
remove the optionality, and also simplifies code that actually reads the
file.

This is part of an effort to get rid of
`Optional{File,Directory}EntryRefDegradesTo{File,Directory}EntryPtr`.
2023-12-08 15:43:00 -08:00
Corentin Jabot
19e2174d54 Revert "[Clang] Eagerly instantiate used constexpr function upon definition. (#73463)"
This reverts commit 030047c432cac133738be68fa0974f70e69dd58d.

Breaks Qt and is inconsistent with GCC.

See the following issue for details:

Fixes #74069
2023-12-02 13:35:27 +01:00
cor3ntin
030047c432
[Clang] Eagerly instantiate used constexpr function upon definition. (#73463)
Despite CWG2497 not being resolved, it is reasonable to expect the
following code to compile (and which is supported by other compilers)

```cpp
  template<typename T> constexpr T f();
  constexpr int g() { return f<int>(); } // #1
  template<typename T> constexpr T f() { return 123; }
  int k[g()];
  // #2
```

To that end, we eagerly instantiate all referenced specializations of
constexpr functions when they are defined.

We maintain a map of (pattern, [instantiations]) independent of
`PendingInstantiations` to avoid having to iterate that list after each
function definition.

We should apply the same logic to constexpr variables, but I wanted to
keep the PR small.

Fixes #73232
2023-11-30 08:45:05 +01:00
Sunil Kuravinakop
d033f51a0a [OpenMP] atomic compare fail : Parser & AST support
Diff Revision: https://reviews.llvm.org/D123235
2023-11-26 13:34:34 -06:00
Krzysztof Parzyszek
ddfed815c9 Revert "[OpenMP] atomic compare fail : Parser & AST support"
This reverts commit edd675ac283909397880f85ba68d0d5f99dc1be2.

This breaks clang build where every component is a shared library.

The file clang/lib/Basic/OpenMPKinds.cpp, which is a part of
libclangBasic.so, uses `getOpenMPClauseName` which isn't:

/usr/bin/ld: CMakeFiles/obj.clangBasic.dir/OpenMPKinds.cpp.o: in functio
n `clang ::getOpenMPSimpleClauseTypeName(llvm::omp::Clause, unsigned int
)':
OpenMPKinds.cpp:(.text._ZN5clang29getOpenMPSimpleClauseTypeNameEN4llvm3o
mp6ClauseEj+0x9b): undefined reference to `llvm::omp::getOpenMPClauseNam
e(llvm::omp::Clause)'
2023-11-20 10:48:06 -06:00
Sunil Kuravinakop
edd675ac28 [OpenMP] atomic compare fail : Parser & AST support
Diff Revision: https://reviews.llvm.org/D123235
2023-11-20 03:05:31 -06:00
Erich Keane
ff219ea9ca
[OpenACC] Initial commits to support OpenACC (#70234)
Initial commits to support OpenACC.  This patchset:

adds a clang-command line argument '-fopenacc', and starts
 to define _OPENACC, albeit to '1' instead of the standardized
value (since we don't properly implement OpenACC yet).

The OpenACC spec defines `_OPENACC` to be equal to the latest standard
implemented. However, since we're not done implementing any standard,
we've defined this by default to be `1`. As it is useful to run our
compiler against existing OpenACC workloads, we're providing a
temporary override flag to change the `_OPENACC` value to be any
entirely digit value, permitting testing against any existing OpenACC
project.

Exactly like the OpenMP parser, the OpenACC pragma parser needs to
consume and reprocess the tokens. This patch sets up the infrastructure
to do so by refactoring the OpenMP version of this into a more general
version that works for OpenACC as well.

Additionally, this adds a few diagnostics and token kinds to get us
started.
2023-11-17 06:29:02 -08:00
Mitch Phillips
a141a9fa97 Revert "[OpenMP] atomic compare fail : Parser & AST support"
This reverts commit 086b65340cca2648a2a91a0a47d28c7d9bafd1e5.

Reason: Broke under -Werror. More details in
https://reviews.llvm.org/D123235
2023-11-08 11:20:17 +01:00
Sunil Kuravinakop
086b65340c [OpenMP] atomic compare fail : Parser & AST support
This is a support for " #pragma omp atomic compare fail ". It has Parser & AST support for now.

Reviewed By: tianshilei1992, ABataev

Differential Revision: https://reviews.llvm.org/D123235
2023-11-07 16:57:50 -06:00
Kazu Hirata
af447dde5e [Serialization] Use llvm::is_contained (NFC) 2023-10-20 23:45:20 -07:00
Jan Svoboda
1afb313b26
[clang][modules] Use file name as requested (#68957)
This prevents redefinition errors due to having multiple paths for the
same module map. (rdar://24116019)

Originally implemented and tested downstream by @bcardosolopes, I just
made use of `FileEntryRef::getNameAsRequested()`.
2023-10-20 09:23:19 -07:00
Kazu Hirata
02f67c097d Use llvm::endianness::{big,little,native} (NFC)
Note that llvm::support::endianness has been renamed to
llvm::endianness while becoming an enum class. This patch replaces
{big,little,native} with llvm::endianness::{big,little,native}.

This patch completes the migration to llvm::endianness and
llvm::endianness::{big,little,native}.  I'll post a separate patch to
remove the migration helpers in llvm/Support/Endian.h:

  using endianness = llvm::endianness;
  constexpr llvm::endianness big = llvm::endianness::big;
  constexpr llvm::endianness little = llvm::endianness::little;
  constexpr llvm::endianness native = llvm::endianness::native;
2023-10-13 23:16:25 -07:00
Krystian Stasiowski
3a3b84b180
[clang] remove ClassScopeFunctionSpecializationDecl (#66636)
This removes the `ClassScopeFunctionSpecializationDecl` `Decl` node, and
instead uses `DependentFunctionTemplateSpecializationInfo` to handle
such declarations. `DependentFunctionTemplateSpecializationInfo` is also
changed to store a `const ASTTemplateArgumentListInfo*` to be more in
line with `FunctionTemplateSpecializationInfo`.

This also changes `FunctionDecl::isFunctionTemplateSpecialization` to
return `true` for dependent specializations, and
`FunctionDecl::getTemplateSpecializationKind`/`FunctionDecl::getTemplateSpecializationKindForInstantiation`
to return `TSK_ExplicitSpecialization` for non-friend dependent
specializations (the same behavior as dependent class scope
`ClassTemplateSepcializationDecl` & `VarTemplateSepcializationDecl`).
2023-10-07 10:55:31 +04:00
Jan Svoboda
28e8ade041 [clang] Fix build after 537344fc
This fixes the following build failure on lldb-x86_64-debian:

/llvm-project/clang/lib/Serialization/ASTReader.cpp:1453:12: error: call to deleted constructor of 'llvm::Error'
    return Err;
           ^~~
/llvm-project/llvm/include/llvm/Support/Error.h:189:3: note: 'Error' has been explicitly marked deleted here
  Error(const Error &Other) = delete;
  ^
/llvm-project/llvm/include/llvm/Support/Error.h:496:18: note: passing argument to parameter 'Err' here
  Expected(Error Err)
                 ^
2023-10-06 15:08:06 -07:00
Jan Svoboda
537344fc50
[clang][modules] Move SLocEntry search into ASTReader (#66966)
In `SourceManager::getFileID()`, Clang performs binary search over its
buffer of `SLocEntries`. For modules, this binary search fully
deserializes the entire `SLocEntry` block for each visited entry. For
some entries, that includes decompressing the associated buffer (e.g.
the predefines buffer, macro expansion buffers, contents of volatile
files), which shows up in profiles of the dependency scanner.

This patch moves the binary search over loaded entries into `ASTReader`,
which can perform cheaper partial deserialization during the binary
search, reducing the wall time of dependency scans by ~3%. This also
reduces the number of retired instructions by ~1.4% on regular
(implicit) modules compilation.

Note that this patch drops the optimizations based on the last lookup ID
(pruning the search space and performing linear search before resorting
to the full binary search). Instead, it reduces the search space by
asking `ASTReader::GlobalSLocOffsetMap` for the containing `ModuleFile`
and only does binary search over entries of single module file.
2023-10-06 14:52:19 -07:00
Jan Svoboda
0dfb5dadc6
[clang][modules] Remove preloaded SLocEntries from PCM files (#66962)
This commit removes the list of SLocEntry offsets to preload eagerly
from PCM files. Commit introducing this functionality (258ae54a) doesn't
clarify why this would be more performant than the lazy approach used
regularly.

Currently, the only SLocEntry the reader is supposed to preload is the
predefines buffer, but in my experience, it's not actually referenced in
most modules, so the time spent deserializing its SLocEntry is wasted.
This is especially noticeable in the dependency scanner, where this
change brings 4.56% speedup on my benchmark.
2023-10-06 12:50:16 -07:00
Shilei Tian
d6254e1b2e Introduce the initial support for OpenMP kernel language (#66844)
This patch starts the support for OpenMP kernel language, basically to write
OpenMP target region in SIMT style, similar to kernel languages such as CUDA.
What included in this first patch is the `ompx_bare` clause for `target teams`
directive. When `ompx_bare` exists, globalization is disabled such that local
variables will not be globalized. The runtime init/deinit function calls will
not be emitted. That being said, almost all OpenMP executable directives are
not supported in the region, such as parallel, task. This patch doesn't include
the Sema checks for that, so the use of them is UB. Simple directives, such as
atomic, can be used. We provide a set of APIs (for C, they are prefix with
`ompx_`; for C++, they are in `ompx` namespace) to get thread id, block id, etc.
Please refer to
https://tianshilei.me/wp-content/uploads/llvm-hpc-2023.pdf for more details.
2023-10-05 17:38:06 -04:00
Giulio Eulisse
4ae5157080
Introduce paged vector (#66430)
The goal of the class is to be an (almost) drop in replacement for
SmallVector and std::vector when those are presized and filled later, as
it happens in SourceManager and ASTReader.

By doing so, sparsely accessed PagedVector can profit from reduced 
memory footprint.
2023-09-30 08:26:19 +03:00
JP Lehr
1bff5f6d0b Revert "[OpenMP] Introduce the initial support for OpenMP kernel language (#66844)"
This reverts commit e997dca3333823ffe2ea3aea288299f551532dcd.
2023-09-29 15:35:10 -05:00
Shilei Tian
e997dca333
[OpenMP] Introduce the initial support for OpenMP kernel language (#66844)
This patch starts the support for OpenMP kernel language, basically to
write
OpenMP target region in SIMT style, similar to kernel languages such as
CUDA.
What included in this first patch is the `ompx_bare` clause for `target
teams`
directive. When `ompx_bare` exists, globalization is disabled such that
local
variables will not be globalized. The runtime init/deinit function calls
will
not be emitted. That being said, almost all OpenMP executable directives
are
not supported in the region, such as parallel, task. This patch doesn't
include
the Sema checks for that, so the use of them is UB. Simple directives,
such as
atomic, can be used. We provide a set of APIs (for C, they are prefix
with
`ompx_`; for C++, they are in `ompx` namespace) to get thread id, block
id, etc.
For more details, you can refer to
https://tianshilei.me/wp-content/uploads/llvm-hpc-2023.pdf.
2023-09-29 13:11:09 -04:00
Jan Svoboda
b0abc9dd44 [clang] NFCI: Use FileEntryRef in ASTReader::GetHeaderFileInfo()
This is the `ASTReader` counterpart to PR #67383.
2023-09-29 09:07:13 -07:00
Chuanqi Xu
7e8a0e4bdc [NFC] [C++20] [Modules] Rename NamedModuleHasInit to NamedModuleHasInit
Address comments in
https://github.com/llvm/llvm-project/pull/67638/files#r1340342453 to
rename the field variable.
2023-09-29 21:49:10 +08:00
Jan Svoboda
de85739ded [clang] NFCI: Use FileEntryRef in additional module maps 2023-09-28 14:49:45 -07:00
Chuanqi Xu
989173c09c
[C++20] [Modules] Don't generate call to an imported module that dont init anything (#67638)
Close https://github.com/llvm/llvm-project/issues/56794

And see https://github.com/llvm/llvm-project/issues/67582 for a detailed
backgrond for the issue.

As required by the Itanium ABI, the module units have to generate the
initialization function. However, the importers are allowed to elide the
call to the initialization function if they are sure the initialization
function doesn't do anything.

This patch implemented this semantics.
2023-09-28 23:29:24 +08:00
Chuanqi Xu
45c160510f [C++20] [Modules] [Serialization] Check input file contents with option ForceCheckCXX20ModulesInputFiles enabled
With overriden input files, e,g,. the compiler get the file from an
in-memroy buffer, the compiler can't get correct modified time information
to indicate whehter the input files are changed or not. Then, the
semantics of ForceCheckCXX20ModulesInputFiles are broken.

In this patch, if both ForceCheckCXX20ModulesInputFiles and
ValidateASTInputFilesContent and enabled, the compiler will still check the
hash value of the contents even if their modification time is the same.
2023-09-14 11:27:50 +08:00
Jan Svoboda
f94695b6eb [clang] NFCI: Use FileEntryRef in FileManager::getBufferForFile() 2023-09-13 15:02:20 -07:00
Jan Svoboda
45bf8e432b [clang] NFCI: Use FileEntryRef in ASTReader 2023-09-10 09:36:47 -07:00
Jan Svoboda
37b08892fc [clang] NFCI: Use FileEntryRef in ModuleMap 2023-09-09 09:12:35 -07:00
Chuanqi Xu
96122b5b71 [C++20] [Modules] Introduce ForceCheckCXX20ModulesInputFiles options for
C++20 modules

Previously, we banned the check for input files from C++20 modules since
we thought the BMI from C++20 modules should be a standalone artifact.

However, during the recent experiment with clangd for modules, I find
it is necessary to tell whether or not a BMI is out-of-date by checking the
input files especially for language servers.

So this patch brings a header search option
ForceCheckCXX20ModulesInputFiles to allow the tools (concretly, clangd)
to check the input files from BMI.
2023-09-08 16:53:12 +08:00
Chuanqi Xu
869111ccf2 [NFC] [C++20] [Modules] Refactor the warning to '-fmodule-file=<BMIPath>' for C++20 modules
Previous implementation of the warning to use `-fmodule-file=<BMIPath>`
for C++20 Modules is not straightforward and it is problematic in case
we read the BMIPath by writing tools based clang components. This patch
refactors it with a simple and direct style.
2023-09-07 17:13:16 +08:00
Chuanqi Xu
f0cd9b2b8a [NFC] [Serialization] Remove unused output parameter 'Imported' in ReadAST 2023-09-07 16:12:53 +08:00
Jens Massberg
c2bf9baf59 Add a concept AST node.
This patch adds a concept AST node (`ConceptLoc`) and uses it at the corresponding places.

There are three objects that might have constraints via concepts:
`TypeConstraint`,  `ConceptSpecializationExpr` and `AutoTypeLoc`.
The first two inherit from `ConceptReference` while the latter has
the information about a possible constraint directly stored in `AutoTypeLocInfo`. It would be nice if the concept information would be stored the same way in all three cases.

Moreover the current structure makes it difficult to deal with these concepts. For example in Clangd accessing the locations of constraints of a `AutoTypeLoc` can only be done with quite ugly hacks.

So we think that it makes sense to create a new AST node for such concepts.

In details we propose the following:
- Rename `ConceptReference` to `ConceptLoc` (or something else what is approriate)
and make it the new AST node.
- `TypeConstraint` and `ConceptSpecializationExpr` do not longer inherit from `ConceptReference` but store a pointer to a `ConceptLoc`.
- `AutoTypeLoc` stores a pointer to `ConceptLoc` instead of storing the concept info in `AutoTypeLocInfo`.

This patch implements a first version of this idea which compiles and where the existing tests pass.
To make this patch as small as possible we keep the existing member functions to access concept data. Later these can be replaced by directly calling the corresponding functions of the `ConceptLoc`s.

Differential Revision: https://reviews.llvm.org/D155858
2023-08-31 10:22:21 +02:00
Jan Svoboda
b9b81e37fe [clang][modules] NFC: Use local instead of ModuleFile member 2023-08-28 09:54:39 -07:00
Jan Svoboda
6fb08d8f55 Reland "[clang][modules] Move UNHASHED_CONTROL_BLOCK up in the AST file"
This reverts commit b6ba804f7775f89f230ee1e62526a2f8225c7966, effectively relanding commit 7d1565727dad3acb54fe76a908630843835d7bc8.

The original commit incorrectly called `ASTWriter::writeUnhashedControlBlock()` before `ASTWriter::collectNonAffectingInputFiles()`, causing SourceLocations/FileIDs in the pragma diagnostic mappings block to be invalid. This is now tested by `clang/test/Modules/diag-mappings-affecting.c`.
2023-08-28 09:54:39 -07:00
Jan Svoboda
d4a9121534 Reland "[clang][modules] Use relative offsets for input files"
This reverts commit 870f1583eed0f22ddfb1a1979a90198c3dc09927, effectively relanding commit b9d78bdc730b2fcfe029a7579c24020536c3fa25.
2023-08-28 09:54:39 -07:00
Jan Svoboda
870f1583ee Revert "[clang][modules] Use relative offsets for input files"
This reverts commit b9d78bdc730b2fcfe029a7579c24020536c3fa25. After this change, all libc++ `clang_modules_include.gen.py` tests started failing on Linux builders: https://luci-milo.appspot.com/ui/p/fuchsia/builders/toolchain.ci/clang-linux-arm64/b8771862804321535569/test-results
2023-08-24 14:43:23 -07:00
Jan Svoboda
b6ba804f77 Revert "[clang][modules] Move UNHASHED_CONTROL_BLOCK up in the AST file"
This reverts commit 7d1565727dad3acb54fe76a908630843835d7bc8.
2023-08-24 14:43:23 -07:00
Jan Svoboda
7d1565727d [clang][modules] Move UNHASHED_CONTROL_BLOCK up in the AST file
When loading (transitively) imported AST file, `ModuleManager::addModule()` first checks it has the expected signature via `readASTFileSignature()`. The signature is part of `UNHASHED_CONTROL_BLOCK`, which is placed at the end of the AST file. This means that just to verify signature of an AST file, we need to skip over all top-level blocks, paging in the whole AST file from disk. This is pretty slow.

This patch moves `UNHASHED_CONTROL_BLOCK` to the start of the AST file, so that it can be read more efficiently. To achieve this, we use dummy signature when first emitting the unhashed control block, and then backpatch the real signature at the end of the serialization process.

This speeds up dependency scanning by over 9% and significantly reduces run-to-run variability of my benchmarks.

Depends on D158572.

Reviewed By: benlangmuir

Differential Revision: https://reviews.llvm.org/D158573
2023-08-24 09:16:04 -07:00
Jan Svoboda
b9d78bdc73 [clang][modules] Use relative offsets for input files
This patch replaces absolute offsets into the input files block with offsets relative to the block start. This makes the whole section "relocatable". I confirmed all other uses of `GetCurrentBitNo()` are turned into relative offsets before being serialized into the AST file.

Reviewed By: benlangmuir

Differential Revision: https://reviews.llvm.org/D158572
2023-08-24 09:16:04 -07:00
Jan Svoboda
6a11557832 [clang][modules] Avoid storing command-line macro definitions into implicitly built PCM files
With implicit modules, it's impossible to load a PCM file that was built using different command-line macro definitions. This is guaranteed by the fact that they contribute to the context hash. This means that we don't need to store those macros into PCM files for validation purposes. This patch avoids serializing them in those circumstances, since there's no other use for command-line macro definitions (besides "-module-file-info").

For a typical Apple project, this speeds up the dependency scan by 5.6% and shrinks the cache with scanning PCMs by 26%.

Reviewed By: benlangmuir

Differential Revision: https://reviews.llvm.org/D158136
2023-08-17 11:11:29 -07:00
Ben Langmuir
dc5cbba319 [clang][modules] Add -Wsystem-headers-in-module=
Add a way to enable -Wsystem-headers only for a specific module. This is
useful for validating a module that would otherwise not see system
header diagnostics without being flooded by diagnostics for unrelated
headers/modules. It's relatively common for a module to be marked
[system] but still wish to validate itself explicitly.

rdar://113401565

Differential Revision: https://reviews.llvm.org/D156948
2023-08-09 10:40:53 -07:00