Commit Graph

2963 Commits

Author SHA1 Message Date
Shilei Tian c4a90db720 [Clang][OpenMP] Add the codegen support for `atomic compare capture`
This patch adds the codegen support for `atomic compare capture` in clang.

Reviewed By: ABataev

Differential Revision: https://reviews.llvm.org/D120290
2022-06-02 21:38:21 -04:00
Aaron Ballman 69da3b6aea Revert "[OpenMP] atomic compare fail : Parser & AST support"
This reverts commit 232bf8189e.

It broke the sanitize buildbot: https://lab.llvm.org/buildbot/#/builders/5/builds/24074

It also reproduces on Windows debug builds as a crash.
2022-05-25 13:34:34 -04:00
Sunil Kuravinakop 232bf8189e [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

Differential Revision: https://reviews.llvm.org/D123235
2022-05-24 23:56:42 -05:00
Mike Rice 9ba937112f [OpenMP] Add parsing/sema support for omp_all_memory reserved locator
Adds support for the reserved locator 'omp_all_memory' for use
in depend clauses with 'out' or 'inout' dependence-types.

Differential Revision: https://reviews.llvm.org/D125828
2022-05-24 10:28:59 -07:00
Serge Pavlov 5537b22ccb Make CompoundStmtBitfields::NumStmts not a bit-field
Number of statements in CompoundStmt is kept in a bit-field of the common
part of Stmt. The field has 24 bits for the number. To allocate a new
bit field (as attempted in https://reviews.llvm.org/D123952), this
number must be reduced, maximal number of statements in a compound
statement becomes smaller. It can result in compilation errors of some
programs.

With this change the number of statements is kept in a field of type
'unsigned int' rather than in bit-field. To make room in CompoundStmtBitfields
LBraceLoc is moved to fields of CompoundStmt.

Differential Revision: https://reviews.llvm.org/D125635
2022-05-20 14:20:09 +07:00
Sam McCall 1dfd8e99f9 [Serialization] Delta encode locations in expansion sloc entries
This is a 1.9% reduction in PCH size in my measurements.

In abbreviated records, VBR6 seems to be slightl better than VBR8 for locations
that may be delta-encoded (i.e. not the first)

Differential Revision: https://reviews.llvm.org/D125952
2022-05-20 01:05:53 +02:00
Sam McCall 4df795bff7 [Serialization] Delta-encode consecutive SourceLocations in TypeLoc
Much of the size of PCH/PCM files comes from stored SourceLocations.
These are encoded using (almost) their raw value, VBR-encoded. Absolute
SourceLocations can be relatively large numbers, so this commonly takes
20-30 bits per location.

We can reduce this by exploiting redundancy: many "nearby" SourceLocations are
stored differing only slightly and can be delta-encoded.
Randam-access loading of AST nodes constrains how long these sequences
can be, but we can do it at least within a node that always gets
deserialized as an atomic unit.

TypeLoc is implemented in this patch as it's a relatively small change
that shows most of the API.
This saves ~3.5% of PCH size, I have local changes applying this technique
further that save another 3%, I think it's possible to get to 10% total.

Differential Revision: https://reviews.llvm.org/D125403
2022-05-19 09:40:44 +02:00
Richard Howell ee51e9795a [clang] serialize ORIGINAL_PCH_DIR relative to BaseDirectory
This diff changes the serialization of the `ORIGINAL_PCH_DIR`
entry in module files to be serialized relative to the module's
`BaseDirectory`. This will allow for the module to be relocatable
across machines.

The path is restored relative to the module's BaseDirectory on
deserialization.

Reviewed By: urnathan

Differential Revision: https://reviews.llvm.org/D124946
2022-05-12 07:31:19 -07:00
Richard Howell f11056943e [clang] serialize SUBMODULE_TOPHEADER relative to BaseDirectory
This diff changes the serialization of the `SUBMODULE_TOPHEADER`
entry in module files to be serialized relative to the module's
`BaseDirectory`. This matches the behavior of the
`SUBMODULE_HEADER` entry and will allow for the module to be
relocatable across machines.

The path is restored relative to the module's `BaseDirectory` on
deserialization.

Reviewed By: urnathan

Differential Revision: https://reviews.llvm.org/D124938
2022-05-12 07:29:37 -07:00
Richard Howell 646e502de0 [clang] add -fmodule-file-home-is-cwd
This diff adds a new frontend flag `-fmodule-file-home-is-cwd`.
The behavior of this flag is similar to
`-fmodule-map-file-home-is-cwd` but does not require the module
map files to be modified to have inputs relative to the cwd.
Instead the output modules will have their `BaseDirectory` set
to the cwd and will try and resolve paths relative to that.

The motiviation for this change is to support relocatable pcm
files that are built on different machines with different paths
without having to alter module map files, which is sometimes not
possible as they are provided by 3rd parties.

Reviewed By: urnathan

Differential Revision: https://reviews.llvm.org/D124874
2022-05-12 07:27:47 -07:00
Erich Keane 017abbb258 Revert ""Re-apply 4b6c2cd642 "Deferred Concept Instantiation Implementation"""""
This reverts commit a425cac31e.

There is another libc++ test, that this time causes us to hit an
assertion. Reverting, likely for a while this time.
2022-05-09 09:12:05 -07:00
Erich Keane a425cac31e "Re-apply 4b6c2cd642 "Deferred Concept Instantiation Implementation""""
This includes a fix for the libc++ issue I ran across with friend
declarations not properly being identified as overloads.

This reverts commit 45c07db31c.
2022-05-09 06:29:47 -07:00
Kugan Vivekanandarajah 2deebc0048 [RFC] Add and sort decl to maintain order instead of inserting in order
ASTWriter::associateDeclWithFile shows a lot in clangd perf profile due to O(n^2) behaviour in insertion of DeclIDs in SortedFileDeclIDs. Instead of doing that, this patch just appends it to the DeclIDs vector and sorts them at the end.

Reviewed By: akyrtzi

Differential Revision: https://reviews.llvm.org/D124840
2022-05-03 17:06:22 +01:00
Erich Keane 45c07db31c Revert "Re-apply 4b6c2cd642 "Deferred Concept Instantiation Implementation"""
This reverts commit a97899108e.

The patch caused some problems with the libc++ `__range_adaptor_closure`
that I haven't been able to figure out the cause of, so I am reverting
while I figure out whether this is a solvable problem/issue with the
  CFE, or libc++ depending on an older 'incorrect' behavior.
2022-05-02 11:12:14 -07:00
Erich Keane a97899108e Re-apply 4b6c2cd642 "Deferred Concept Instantiation Implementation""
This reverts commit 0c31da4838.

I've solved the issue with the PointerUnion by making the
`FunctionTemplateDecl` pointer be a NamedDecl, that could be a
`FunctionDecl` or `FunctionTemplateDecl` depending.  This is enforced
with an assert.
2022-05-02 07:49:26 -07:00
Erich Keane 0c31da4838 Revert "Deferred Concept Instantiation Implementation"
This reverts commit 4b6c2cd647.

The patch caused numerous ARM 32 bit build failures, since we added a
5th item to the PointerUnion, and went over the 2-bits available in the
32 bit pointers.
2022-05-02 06:25:38 -07:00
Erich Keane 4b6c2cd647 Deferred Concept Instantiation Implementation
As reported here: https://github.com/llvm/llvm-project/issues/44178

Concepts are not supposed to be instantiated until they are checked, so
this patch implements that and goes through significant amounts of work
to make sure we properly re-instantiate the concepts correctly.

Differential Revision: https://reviews.llvm.org/D119544
2022-05-02 05:49:15 -07:00
Volodymyr Sapsai d32c685e10 [modules] Merge equivalent extensions and diagnose ivar redeclarations for extensions loaded from different modules.
Emitting metadata for the same ivar multiple times can lead to
miscompilations. Objective-C runtime adds offsets to calculate ivar
position in memory and presence of duplicate offsets causes wrong final
position thus overwriting unrelated memory.

Such a situation is impossible with modules disabled as clang diagnoses
ivar redeclarations during sema checks after parsing
(`Sema::ActOnFields`). Fix the case with modules enabled by checking
during deserialization if ivar is already declared. We also support
a use case where the same category ends up in multiple modules. We
don't want to treat this case as ivar redeclaration and instead merge
corresponding ivars.

rdar://83468070

Differential Revision: https://reviews.llvm.org/D121177
2022-04-27 15:52:59 -07:00
Jun Zhang 218dcdad8a
[Clang] Use std::move in GlobalModuleIndex::readIndex. NFC
BitstreamCursors are heavy-weight objects that should not be passed by value.

Differential Revision: https://reviews.llvm.org/D123436
2022-04-26 16:45:01 +08:00
Sam McCall 6035649d4c [Serialization] Remove dead TYPE_FUNCTION_PROTO abbreviation. NFC
It was added in 01b2cb47 but never used.
2022-04-25 21:16:54 +02:00
Sam McCall 0cd5cd19af [Serialization] write expr dependence bits as a single integer
When exprs are written unabbreviated:
  - these were encoded as 5 x vbr6 = 30 bits
  - now they fit exactly into a one-chunk vbr = 6 bits

clangd --check=clangd/AST.cpp reports ~1% reduction in PCH size
(42826720->42474460)

Differential Revision: https://reviews.llvm.org/D124250
2022-04-25 12:09:40 +02:00
Sam McCall e80ee1829c Reland [Frontend] avoid copy of PCH data when PrecompiledPreamble stores it in memory
This reverts commit eadf352707.

The reland fixes a couple of places in clang that were unneccesarily
requesting a null-terminated buffer of the PCH, and hitting assertions.
2022-04-21 21:15:39 +02:00
Richard Smith 63814be4fa [modules] Merge variable template specializations. 2022-04-19 14:48:42 -07:00
Shilei Tian e8760b51ee [Clang][OpenMP] Use bitfields for flags in `OMPAtomicDirective`
As suggested in D120290.

Reviewed By: ABataev

Differential Revision: https://reviews.llvm.org/D123862
2022-04-15 21:34:28 -04:00
Jan Svoboda d79ad2f1db [clang][lex] NFCI: Use FileEntryRef in PPCallbacks::InclusionDirective()
This patch changes type of the `File` parameter in `PPCallbacks::InclusionDirective()` from `const FileEntry *` to `Optional<FileEntryRef>`.

With the API change in place, this patch then removes some uses of the deprecated `FileEntry::getName()` (e.g. in `DependencyGraph.cpp` and `ModuleDependencyCollector.cpp`).

Reviewed By: dexonsmith, bnbarham

Differential Revision: https://reviews.llvm.org/D123574
2022-04-14 10:46:12 +02:00
Jennifer Yu 187ccc66fa [clang][OpenMP5.1] Initial parsing/sema for has_device_addr
Added basic parsing/sema/ support for the 'has_device_addr' clause.

Differential Revision: https://reviews.llvm.org/D123402
2022-04-08 21:19:38 -07:00
Argyrios Kyrtzidis 330268ba34 [Support/Hash functions] Change the `final()` and `result()` of the hashing functions to return an array of bytes
Returning `std::array<uint8_t, N>` is better ergonomics for the hashing functions usage, instead of a `StringRef`:

* When returning `StringRef`, client code is "jumping through hoops" to do string manipulations instead of dealing with fixed array of bytes directly, which is more natural
* Returning `std::array<uint8_t, N>` avoids the need for the hasher classes to keep a field just for the purpose of wrapping it and returning it as a `StringRef`

As part of this patch also:

* Introduce `TruncatedBLAKE3` which is useful for using BLAKE3 as the hasher type for `HashBuilder` with non-default hash sizes.
* Make `MD5Result` inherit from `std::array<uint8_t, 16>` which improves & simplifies its API.

Differential Revision: https://reviews.llvm.org/D123100
2022-04-05 21:38:06 -07:00
Volodymyr Sapsai 29444f0444 [modules] Merge ObjC interface ivars with anonymous types.
Without the fix ivars with anonymous types can trigger errors like

> error: 'TestClass::structIvar' from module 'Target' is not present in definition of 'TestClass' provided earlier
> [...]
> note: declaration of 'structIvar' does not match

It happens because types of ivars from different modules are considered
to be different. And it is caused by not merging anonymous `TagDecl`
from different modules.

To fix that I've changed `serialization::needsAnonymousDeclarationNumber`
to handle anonymous `TagDecl` inside `ObjCInterfaceDecl`. But that's not
sufficient as C code inside `ObjCInterfaceDecl` doesn't use interface
decl as a decl context but switches to its parent (TranslationUnit in
most cases).  I'm changing that to make `ObjCContainerDecl` the lexical
decl context but keeping the semantic decl context intact.

Test "check-dup-decls-inside-objc.m" doesn't reflect a change in
functionality but captures the existing behavior to prevent regressions.

rdar://85563013

Differential Revision: https://reviews.llvm.org/D118525
2022-04-04 18:48:30 -07:00
Chuanqi Xu 3cec39b91c [C++20] [Modules] Don't generate strong function of a partition in importing modules
This solves the multiple defintiion issue
https://github.com/llvm/llvm-project/issues/54269.

I think the cause of the bug might be an oversight. We just forget to
edit this when implementing partitions. And it should be a good fix.

Reviewed By: iains

Differential Revision: https://reviews.llvm.org/D121271
2022-04-01 14:36:04 +08:00
David Goldman d9739f29cd Serialize PragmaAssumeNonNullLoc to support preambles
Previously, if a `#pragma clang assume_nonnull begin` was at the
end of a premable with a `#pragma clang assume_nonnull end` at the
end of the main file, clang would diagnose an unterminated begin in
the preamble and an unbalanced end in the main file.

With this change, those errors no longer occur and the case above is
now properly handled. I've added a corresponding test to clangd,
which makes use of preambles, in order to verify this works as
expected.

Differential Revision: https://reviews.llvm.org/D122179
2022-03-31 11:08:01 -04:00
James Y Knight d614874900 [Clang] Implement __builtin_source_location.
This builtin returns the address of a global instance of the
`std::source_location::__impl` type, which must be defined (with an
appropriate shape) before calling the builtin.

It will be used to implement std::source_location in libc++ in a
future change. The builtin is compatible with GCC's implementation,
and libstdc++'s usage. An intentional divergence is that GCC declares
the builtin's return type to be `const void*` (for
ease-of-implementation reasons), while Clang uses the actual type,
`const std::source_location::__impl*`.

In order to support this new functionality, I've also added a new
'UnnamedGlobalConstantDecl'. This artificial Decl is modeled after
MSGuidDecl, and is used to represent a generic concept of an lvalue
constant with global scope, deduplicated by its value. It's possible
that MSGuidDecl itself, or some of the other similar sorts of things
in Clang might be able to be refactored onto this more-generic
concept, but there's enough special-case weirdness in MSGuidDecl that
I gave up attempting to share code there, at least for now.

Finally, for compatibility with libstdc++'s <source_location> header,
I've added a second exception to the "cannot cast from void* to T* in
constant evaluation" rule. This seems a bit distasteful, but feels
like the best available option.

Reviewers: aaron.ballman, erichkeane

Differential Revision: https://reviews.llvm.org/D120159
2022-03-28 18:29:02 -04:00
Iain Sandoe f8846229c4 [C++20][Modules][HU 3/5] Emit module macros for header units.
For header units we build the top level module directly from the header
that it represents and macros defined in this TU need to be emitted (when
such a definition is live at the end of the TU).

Differential Revision: https://reviews.llvm.org/D121097
2022-03-26 16:30:40 +00:00
Corentin Jabot 3784e8ccfb [Clang] Fix Unevaluated Lambdas
Unlike other types, when lambdas are instanciated,
they are recreated from scratch.
When an unevaluated lambdas appear in the type of a function,
parameter it is instanciated in the wrong declaration context,
as parameters are transformed before the function.

To support lambda in function parameters, we try to
compute whether they are dependant without looking at the
declaration context.

This is a short term stopgap solution to avoid clang
iceing. A better fix might be to inject some kind of
transparent declaration with correctly computed dependency
for function parameters, variable templates, etc.

Fixes https://github.com/llvm/llvm-project/issues/50376
Fixes https://github.com/llvm/llvm-project/issues/51414
Fixes https://github.com/llvm/llvm-project/issues/51416
Fixes https://github.com/llvm/llvm-project/issues/51641
Fixes https://github.com/llvm/llvm-project/issues/54296

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D121532
2022-03-25 19:16:45 +01:00
Hubert Tong ce21c926f8 [Clang] Work with multiple pragmas weak before definition
Update `WeakUndeclaredIdentifiers` to hold a collection of weak
aliases per identifier instead of only one.

This also allows the "used" state to be removed from `WeakInfo`
because it is really only there as an alternative to removing
processed map entries, and we can represent that using an empty set
now. The serialization code is updated for the removal of the field.
Additionally, a PCH test is added for the new functionality.

The records are grouped by the "target" identifier, which was already
being used as a key for lookup purposes. We also store only one record
per alias name; combined, this means that diagnostics are grouped by
the "target" and limited to one per alias (which should be acceptable).

Fixes PR28611.
Fixes llvm/llvm-project#28985.

Reviewed By: aaron.ballman, cebowleratibm

Differential Revision: https://reviews.llvm.org/D121927

Co-authored-by: Rachel Craik <rcraik@ca.ibm.com>
Co-authored-by: Jamie Schmeiser <schmeise@ca.ibm.com>
2022-03-24 20:17:49 -04:00
Mike Rice f82ec5532b [OpenMP] Initial parsing/sema for the 'omp target parallel loop' construct
Adds basic parsing/sema/serialization support for the
 #pragma omp target parallel loop directive.

Differential Revision: https://reviews.llvm.org/D122359
2022-03-24 09:19:00 -07:00
Mike Rice 2cedaee6f7 [OpenMP] Initial parsing/sema for the 'omp parallel loop' construct
Adds basic parsing/sema/serialization support for the
  #pragma omp parallel loop directive.

 Differential Revision: https://reviews.llvm.org/D122247
2022-03-22 13:55:47 -07:00
Mike Rice 6bd8dc91b8 [OpenMP] Initial parsing/sema for the 'omp target teams loop' construct
Adds basic parsing/sema/serialization support for the
 #pragma omp target teams loop directive.

Differential Revision: https://reviews.llvm.org/D122028
2022-03-18 13:48:32 -07:00
Benjamin Kramer 5d2ce7663b Use llvm::append_range instead of push_back loops where applicable. NFCI. 2022-03-18 01:25:34 +01:00
Mike Rice 79f661edc1 [OpenMP] Initial parsing/sema for the 'omp teams loop' construct
Adds basic parsing/sema/serialization support for the #pragma omp teams loop
directive.

Differential Revision: https://reviews.llvm.org/D121713
2022-03-16 14:39:18 -07:00
Yonghong Song 3251ba2d0f [Attr] Fix a btf_type_tag AST generation
Current ASTContext.getAttributedType() takes attribute kind,
ModifiedType and EquivType as the hash to decide whether an AST node
has been generated or note. But this is not enough for btf_type_tag
as the attribute might have the same ModifiedType and EquivType, but
still have different string associated with attribute.

For example, for a data structure like below,
  struct map_value {
        int __attribute__((btf_type_tag("tag1"))) __attribute__((btf_type_tag("tag3"))) *a;
        int __attribute__((btf_type_tag("tag2"))) __attribute__((btf_type_tag("tag4"))) *b;
  };
The current ASTContext.getAttributedType() will produce
an AST similar to below:
  struct map_value {
        int __attribute__((btf_type_tag("tag1"))) __attribute__((btf_type_tag("tag3"))) *a;
        int __attribute__((btf_type_tag("tag1"))) __attribute__((btf_type_tag("tag3"))) *b;
  };
and this is incorrect.

It is very difficult to use the current AttributedType as it is hard to
get the tag information. To fix the problem, this patch introduced
BTFTagAttributedType which is similar to AttributedType
in many ways but with an additional BTFTypeTagAttr. The tag itself can
be retrieved with BTFTypeTagAttr.
With the new BTFTagAttributed type, the debuginfo code can be greatly
simplified compared to previous TypeLoc based approach.

Differential Revision: https://reviews.llvm.org/D120296
2022-03-16 08:46:52 -07:00
Fangrui Song 407c721ceb [Support] Change zlib::compress to return void
With a sufficiently large output buffer, the only failure is Z_MEM_ERROR.
Check it and call the noreturn report_bad_alloc_error if applicable.
resize_for_overwrite may call report_bad_alloc_error as well.

Now that there is no other error type, we can replace the return type with void
and simplify call sites.

Reviewed By: ikudrin

Differential Revision: https://reviews.llvm.org/D121512
2022-03-14 11:38:04 -07:00
Jan Svoboda b45888e959 [clang][modules] Report module maps affecting `no_undeclared_includes` modules
Since D106876, PCM files don't report module maps as input files unless they contributed to the compilation.

Reporting only module maps of (transitively) imported modules is not enough, though. For modules marked with `[no_undeclared_includes]`, other module maps affect the compilation by introducing anti-dependencies.

This patch makes sure such module maps are being reported as input files.

Depends on D120463.

Reviewed By: dexonsmith

Differential Revision: https://reviews.llvm.org/D120464
2022-03-07 10:47:46 +01:00
Adam Czachorowski 8f4ea36bfe [clang] Improve laziness of resolving module map headers.
clang has support for lazy headers in module maps - if size and/or
modtime and provided in the cppmap file, headers are only resolved when
an include directive for a file with that size/modtime is encoutered.

Before this change, the lazy resolution was all-or-nothing per module.
That means as soon as even one file in that module potentially matched
an include, all lazy files in that module were resolved. With this
change, only files with matching size/modtime will be resolved.

The goal is to avoid unnecessary stat() calls on non-included files,
which is especially valuable on networked file systems, with higher
latency.

Differential Revision: https://reviews.llvm.org/D120569
2022-03-01 15:56:23 +01:00
Iain Sandoe c9cc8035eb [C++20][Modules][2/8] Add enumerations for partition modules and stream them.
This is an initial enabling patch for module partition support.
We add enumerations for partition interfaces/implementations.

This means that the module kind enumeration now occupies three
bits, so the AST streamer is adjusted for this.  Adding one bit there
seems preferable to trying to overload the meanings of existing
kinds (and we will also want to add a C++20 header unit case later).

Differential Revision: https://reviews.llvm.org/D114714
2022-02-22 10:08:15 +00:00
Kadir Cetinkaya 977b1f574f
[clang][ASTReader] Fix memory leak while reading FriendTemplateDecls
Allocate on ASTContext, rather than just on heap, so that template
parameter lists are freed up.

Differential Revision: https://reviews.llvm.org/D120081
2022-02-18 12:16:38 +01:00
Volodymyr Sapsai fa4a0f1d31 [modules] Add a flag for TagDecl if it was a definition demoted to a declaration.
For redeclaration chains we maintain an invariant of having only a
single definition in the chain. In a single translation unit we make
sure not to create duplicates. But modules are separate translation
units and they can contain definitions for the same symbol
independently. When we load such modules together, we need to demote
duplicate definitions to keep the AST invariants.

Some AST clients are interested in distinguishing
declaration-that-was-demoted-from-definition and
declaration-that-was-never-a-definition. For that purpose introducing
`IsThisDeclarationADemotedDefinition`. No functional change intended.

rdar://84677782

Differential Revision: https://reviews.llvm.org/D118855
2022-02-14 16:04:40 -08:00
Alex Lorenz 00cd6c0420 [Preprocessor] Reduce the memory overhead of `#define` directives (Recommit)
Recently we observed high memory pressure caused by clang during some parallel builds.
We discovered that we have several projects that have a large number of #define directives
in their TUs (on the order of millions), which caused huge memory consumption in clang due
to a lot of allocations for MacroInfo. We would like to reduce the memory overhead of
clang for a single #define to reduce the memory overhead for these files, to allow us to
reduce the memory pressure on the system during highly parallel builds. This change achieves
that by removing the SmallVector in MacroInfo and instead storing the tokens in an array
allocated using the bump pointer allocator, after all tokens are lexed.

The added unit test with 1000000 #define directives illustrates the problem. Prior to this
change, on arm64 macOS, clang's PP bump pointer allocator allocated 272007616 bytes, and
used roughly 272 bytes per #define. After this change, clang's PP bump pointer allocator
allocates 120002016 bytes, and uses only roughly 120 bytes per #define.

For an example test file that we have internally with 7.8 million #define directives, this
change produces the following improvement on arm64 macOS: Persistent allocation footprint for
this test case file as it's being compiled to LLVM IR went down 22% from 5.28 GB to 4.07 GB
and the total allocations went down 14% from 8.26 GB to 7.05 GB. Furthermore, this change
reduced the total number of allocations made by the system for this clang invocation from
1454853 to 133663, an order of magnitude improvement.

The recommit fixes the LLDB build failure.

Differential Revision: https://reviews.llvm.org/D117348
2022-02-14 09:27:44 -08:00
Alex Lorenz 3f05192c4c Revert "[Preprocessor] Reduce the memory overhead of `#define` directives"
This reverts commit 0d9b91524e.

This change broke LLDB's build. I will need to recommit after fixing LLDB.
2022-02-11 15:53:16 -08:00
Alex Lorenz 0d9b91524e [Preprocessor] Reduce the memory overhead of `#define` directives
Recently we observed high memory pressure caused by clang during some parallel builds.
We discovered that we have several projects that have a large number of #define directives
in their TUs (on the order of millions), which caused huge memory consumption in clang due
to a lot of allocations for MacroInfo. We would like to reduce the memory overhead of
clang for a single #define to reduce the memory overhead for these files, to allow us to
reduce the memory pressure on the system during highly parallel builds. This change achieves
that by removing the SmallVector in MacroInfo and instead storing the tokens in an array
allocated using the bump pointer allocator, after all tokens are lexed.

The added unit test with 1000000 #define directives illustrates the problem. Prior to this
change, on arm64 macOS, clang's PP bump pointer allocator allocated 272007616 bytes, and
used roughly 272 bytes per #define. After this change, clang's PP bump pointer allocator
allocates 120002016 bytes, and uses only roughly 120 bytes per #define.

For an example test file that we have internally with 7.8 million #define directives, this
change produces the following improvement on arm64 macOS: Persistent allocation footprint for
this test case file as it's being compiled to LLVM IR went down 22% from 5.28 GB to 4.07 GB
and the total allocations went down 14% from 8.26 GB to 7.05 GB. Furthermore, this change
reduced the total number of allocations made by the system for this clang invocation from
1454853 to 133663, an order of magnitude improvement.

Differential Revision: https://reviews.llvm.org/D117348
2022-02-11 15:01:10 -08:00
Chuanqi Xu 8c930cef0e [NFC] [Modules] Refactor ODR checking for default template argument in
ASTReader

This is a cleanup to reduce the lines of code to handle default template
argument in ASTReader.

Reviewed By: urnathan

Differential Revision: https://reviews.llvm.org/D118437
2022-02-10 10:10:10 +08:00