This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated. The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.
This is part of an effort to migrate from llvm::Optional to
std::optional:
https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
This is a follow-up to D134224. The original patch added new `ExcludedHeader` enumerator to `ModuleMap::ModuleHeaderRole` and started associating headers with the modules they were excluded from. This was necessary to consider their module maps as "affecting" in certain situations and in turn serialize them into the PCM.
The association of the header and module needs to be handled when deserializing the PCM as well, though. This patch fixes a potential assertion failure and a regression. This essentially reverts parts of feb54b6ded.
Reviewed By: Bigcheese
Differential Revision: https://reviews.llvm.org/D135381
Per the documentation, these restrictions were intended to apply to textual headers but previously this didn't work because we decided there was no requesting module when the `#include` was in a textual header.
A `-cc1` flag is provided to restore the old behavior for transitionary purposes.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D132779
When Clang encounters `@import M.Private` during implicit build, it precompiles module `M` and looks through its submodules. If the `Private` submodule is not found, Clang assumes `@import M_Private`. In the dependency scanner, we don't capture the dependency on `M`, since it's not imported. It's an affecting module, though: compilation of the import statement will fail when implicit modules are disabled and `M` is not precompiled and explicitly provided. This patch fixes that.
Depends on D132430.
Reviewed By: benlangmuir
Differential Revision: https://reviews.llvm.org/D132502
When compiling a module, its semantics and Clang's behavior are affected by other modules. These modules are typically the **imported** ones. However, during implicit build, some modules end up being compiled and read without being actually imported. This patch starts tracking such modules and serializing them into `.pcm` files. This enables the dependency scanner to construct explicit compilations that mimic implicit build.
Reviewed By: benlangmuir
Differential Revision: https://reviews.llvm.org/D132430
The commit of af2d11b1d5 missed a case where
the value of a suggested module needed to be reset to nullptr. Fixed thus
and added a testcase to cover the circumstance.
In the case of static compilation the file system is pretty much read-only
and taking a snapshot of it usually is sufficient. In the interactive C++
case the compilation is longer and people can create and include files, etc.
In that case we often do not want to open files or cache failures unless is
absolutely necessary.
This patch extends the original API call by forwarding some optional flags,
so we can continue use it in the previous way with no breakage.
Signed-off-by: Jun Zhang <jun@junz.org>
Differential Revision: https://reviews.llvm.org/D131241
The #warning directive is standard in C++2b and C2x,
this adjusts the pedantic and extensions warning accordingly.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D130415
Diagnostic for `-Wauto-import` shouldn't be a warning because it doesn't
represent a potential problem in code that should be fixed. And the
emitted fix-it is likely to trigger `-Watimport-in-framework-header`
which makes it challenging to have a warning-free codebase. But it is
still useful to see how include directives are translated into modular
imports and which module a header belongs to, that's why keep it as a remark.
Keep `-Wauto-import` for now to allow a gradual migration for codebases
using `-Wno-auto-import`, e.g., `-Weverything -Wno-auto-import`.
rdar://79594287
Differential Revision: https://reviews.llvm.org/D130138
This addresses [cpp.include]/7
(when encountering #include header-name)
If the header identified by the header-name denotes an importable header, it
is implementation-defined whether the #include preprocessing directive is
instead replaced by an import directive.
In this implementation, include translation is performed _only_ for headers
in the Global Module fragment, so:
```
module;
#include "will-be-translated.h" // IFF the header unit is available.
export module M;
#include "will-not-be-translated.h" // even if the header unit is available
```
The reasoning is that, in general, includes in the module purview would not
be validly translatable (they would have to immediately follow the module
decl and without any other intervening decls). Otherwise that would violate
the rules on contiguous import directives.
This would be quite complex to track in the preprocessor, and for relatively
little gain (the user can 'import "will-not-be-translated.h";' instead.)
TODO: This is one area where it becomes increasingly difficult to disambiguate
clang modules in C++ from C++ standard modules. That needs to be addressed in
both the driver and the FE.
Differential Revision: https://reviews.llvm.org/D128981
"Ascii" StringLiteral instances are actually narrow strings
that are UTF-8 encoded and do not have an encoding prefix.
(UTF8 StringLiteral are also UTF-8 encoded strings, but with
the u8 prefix.
To avoid possible confusion both with actuall ASCII strings,
and with future works extending the set of literal encodings
supported by clang, this rename StringLiteral::isAscii() to
isOrdinary(), matching C++ standard terminology.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D128762
This speeds up preprocessing, specifically for preprocessing the clang sources time is reduced by about -36%,
using measurements on M1Pro with a release+thinLTO build.
Differential Revision: https://reviews.llvm.org/D127379
The `EndLoc` parameter was always unset so no fixit was emitted. But it is also unnecessary for determining the range so we can remove it.
Differential Revision: https://reviews.llvm.org/D127251
This is a commit with the following changes:
* Remove `ExcludedPreprocessorDirectiveSkipMapping` and related functionality
Removes `ExcludedPreprocessorDirectiveSkipMapping`; its intended benefit for fast skipping of excluded directived blocks
will be superseded by a follow-up patch in the series that will use dependency scanning lexing for the same purpose.
* Refactor dependency scanning to produce pre-lexed preprocessor directive tokens, instead of minimized sources
Replaces the "source minimization" mechanism with a mechanism that produces lexed dependency directives tokens.
* Make the special lexing for dependency scanning a first-class feature of the `Preprocessor` and `Lexer`
This is bringing the following benefits:
* Full access to the preprocessor state during dependency scanning. E.g. a component can see what includes were taken and where they were located in the actual sources.
* Improved performance for dependency scanning. Measurements with a release+thin-LTO build shows ~ -11% reduction in wall time.
* Opportunity to use dependency scanning lexing to speed-up skipping of excluded conditional blocks during normal preprocessing (as follow-up, not part of this patch).
For normal preprocessing measurements show differences are below the noise level.
Since, after this change, we don't minimize sources and pass them in place of the real sources, `DependencyScanningFilesystem` is not technically necessary, but it has valuable performance benefits for caching file `stat`s along with the results of scanning the sources. So the setup of using the `DependencyScanningFilesystem` during a dependency scan remains.
Differential Revision: https://reviews.llvm.org/D125486
Differential Revision: https://reviews.llvm.org/D125487
Differential Revision: https://reviews.llvm.org/D125488
When a preprocessor directive is unknown outside of a skipped
conditional block, we give an error diagnostic because we don't know
how to proceed with preprocessing. But when the directive is in a
skipped conditional block, we would not diagnose it on the theory that
the directive may be known to an implementation other than Clang.
Now, for unknown directives inside a skipped conditional block, we
diagnose the unknown directive as a warning if it is sufficiently
similar to a directive specific to preprocessor conditional blocks. For
example, we'll warn about `#esle` and suggest `#else` but we won't warn
about `#progma` because it's not a directive specific to preprocessor
conditional blocks.
Fixes#51598
Differential Revision: https://reviews.llvm.org/D124726
This adds an extension warning when using the preprocessor conditionals
in a language mode they're not officially supported in, and an opt-in
warning for compatibility with previous standards.
Fixes#55306
Differential Revision: https://reviews.llvm.org/D125178
This adds the -Wgnu-line-marker diagnostic flag, grouped under -Wgnu,
to warn about use of the GNU linemarker preprocessor extension.
Fixes#55067
Differential Revision: https://reviews.llvm.org/D124534
> Includes regression test for problem noted by @hans.
> is reverts commit 973de71.
>
> Differential Revision: https://reviews.llvm.org/D106898
Feature implemented as-is is fairly expensive and hasn't been used by
libc++. A potential reimplementation is possible if libc++ become
interested in this feature again.
Differential Revision: https://reviews.llvm.org/D123885
This patch removes uses of the deprecated `DirectoryEntry::getName()` from the `ModuleMap::diagnoseHeaderInclusion()` function by using `{File,Directory}EntryRef` instead.
Reviewed By: bnbarham
Differential Revision: https://reviews.llvm.org/D123856
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
The `const DirectoryLookup *` out-parameter of `{HeaderSearch,Preprocessor}::LookupFile()` is assigned the most recently used search directory, which callers use to implement `#include_next`.
From the function signature it's not obvious the `const DirectoryLookup *` is being used as an iterator. This patch introduces `ConstSearchDirIterator` to make that affordance obvious. This would've prevented a bug that occurred after initially landing D116750.
Reviewed By: ahoppen
Differential Revision: https://reviews.llvm.org/D117566
This patch addresses a FIXME and de-duplicates some `#include_next` logic
Depends on D119714.
Reviewed By: ahoppen
Differential Revision: https://reviews.llvm.org/D119716
The purpose of the `FileNotFound` preprocessor callback was to add the ability to recover from failed header lookups. This was to support downstream project.
However, injecting additional search path while performing header search can invalidate currently used iterators/references to `DirectoryLookup` in `Preprocessor` and `HeaderSearch`.
The downstream project ended up maintaining a separate patch to further tweak the functionality. Since we don't have any upstream users nor open source downstream users, I'd like to remove this callback for good to prevent future misuse. I doubt there are any actual downstream users, since the functionality is definitely broken at the moment.
Reviewed By: ahoppen
Differential Revision: https://reviews.llvm.org/D119708
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
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
This patch replaces the exact include count of each file in `HeaderFileInfo` with a set of included files in `Preprocessor`.
The number of includes isn't a property of a header file but rather a preprocessor state. The exact number of includes is not used anywhere except statistic tracking.
Reviewed By: vsapsai
Differential Revision: https://reviews.llvm.org/D114095
The `{HeaderSearch,Preprocessor}::LookupFile()` functions take an out-parameter `const DirectoryLookup *&`. Most callers end up creating a `const DirectoryLookup *` variable that's otherwise unused.
This patch changes the out-parameter from reference to a pointer, making it possible to simply pass `nullptr` to the function without the ceremony.
Reviewed By: ahoppen
Differential Revision: https://reviews.llvm.org/D117312
This patch refactors the code that checks whether a file has just been included for the first time.
The `HeaderSearch::FirstTimeLexingFile` function is removed and the information is threaded to the original call site from `HeaderSearch::ShouldEnterIncludeFile`. This will make it possible to avoid tracking the number of includes in a follow up patch.
Depends on D114092.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D114093
Some time back I extended GCC's '# NNN' line marker semantics.
Specifically popping to a blank filename will restore the filename to
that of the popped-to include. Restore to line 5 of including file
(escaped BOL #'s to avoid git eliding them):
\# 5 "" 2
Added documentation for this line control extension.
This was useful in developing modules tests, but turned out to also be
useful with machine-generated source code. Specifically, a generated
include file that itself includes fragments from elsewhere. The
ability to pop to the generated include file -- with its full path
prefix -- is useful for diagnostic & debug purposes. For instance
something like:
// Machine generated -- DO NOT EDIT
Type Var = {
\# 7 "encoded.dsl" 1 // push to snippet-container
{snippet, of, code}
\# 6 " 2 // Restore to machined-generated source
,
};
// user-code
...
\#include "dsl.h"
...
That pop to "" will restore the filename to '..includepath../dsl.h',
which is better than restoring to plain "dsl.h".
Differential Revision: https://reviews.llvm.org/D113425
Use the new sys::path::is_style_posix() and is_style_windows() in a few
places that need to detect the system's native path style.
In llvm/lib/Support/Path.cpp, this patch removes most uses of the
private `real_style()`, where is_style_posix() and is_style_windows()
are just a little tidier.
Elsewhere, this removes `_WIN32` macro checks. Added a FIXME to a
FileManagerTest that seemed fishy, but maintained the existing
behaviour.
Differential Revision: https://reviews.llvm.org/D112289
This patch propagates the import `SourceLocation` into `HeaderSearch::lookupModule`. This enables remarks on search path usage (implemented in D102923) to point to the source code that initiated header search.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D111557
Also do not warn on `#define _foo` or `#undef _foo`.
Only global scope names starting with _[a-z] are reserved, not the use
of such an identifier in any other context.
This patch adds a new preprocessor extension ``#pragma clang final``
which enables warning on undefinition and re-definition of macros.
The intent of this warning is to extend beyond ``-Wmacro-redefined`` to
warn against any and all alterations to macros that are marked `final`.
This warning is part of the ``-Wpedantic-macros`` diagnostics group.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D108567
This patch adds `#pragma clang deprecated` to enable deprecation of
preprocessor macros.
The macro must be defined before `#pragma clang deprecated`. When
deprecating a macro a custom message may be optionally provided.
Warnings are emitted at the use site of a deprecated macro, and can be
controlled via the `-Wdeprecated` warning group.
This patch takes some rough inspiration and a few lines of code from
https://reviews.llvm.org/D67935.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D106732
> `#pragma clang include_instead(<header>)` is a pragma that can be used
> by system headers (and only system headers) to indicate to a tool that
> the file containing said pragma is an implementation-detail header and
> should not be directly included by user code.
>
> The library alternative is very messy code that can be seen in the first
> diff of D106124, and we'd rather avoid that with something more
> universal.
>
> This patch takes the first step by warning a user when they include a
> detail header in their code, and suggests alternative headers that the
> user should include instead. Future work will involve adding a fixit to
> automate the process, as well as cleaning up modules diagnostics to not
> suggest said detail headers. Other tools, such as clangd can also take
> advantage of this pragma to add the correct user headers.
>
> Differential Revision: https://reviews.llvm.org/D106394
This caused compiler crashes in Chromium builds involving PCH and an include
directive with macro expansion, when Token::getLiteralData() returned null. See
the code review for details.
This reverts commit e8a64e5491.
`#pragma clang include_instead(<header>)` is a pragma that can be used
by system headers (and only system headers) to indicate to a tool that
the file containing said pragma is an implementation-detail header and
should not be directly included by user code.
The library alternative is very messy code that can be seen in the first
diff of D106124, and we'd rather avoid that with something more
universal.
This patch takes the first step by warning a user when they include a
detail header in their code, and suggests alternative headers that the
user should include instead. Future work will involve adding a fixit to
automate the process, as well as cleaning up modules diagnostics to not
suggest said detail headers. Other tools, such as clangd can also take
advantage of this pragma to add the correct user headers.
Differential Revision: https://reviews.llvm.org/D106394
C++23 will make these conversions ambiguous - so fix them to make the
codebase forward-compatible with C++23 (& a follow-up change I've made
will make this ambiguous/invalid even in <C++23 so we don't regress
this & it generally improves the code anyway)
Kazu Hirata