The minimizer strips out single-line comments (introduced by `//`). This sequence of characters can also appear in `#include` or `#import` directives where they play the role of path separators. We already avoid stripping this character sequence for `#include` but not for `#import` (which has the same semantics). This patch makes it so `#import <A//A.h>` is not affected by minimization. Previously, we would incorrectly reduce it into `#import <A`.
Reviewed By: arphaman
Differential Revision: https://reviews.llvm.org/D119226
The minimizer tries to squash multi-line macro definitions into single line. For that to work, contents of each line need to be separated by a space. Since we always strip leading whitespace on lines of a macro definition, the code currently tries to preserve exactly one space that appeared before the backslash.
This means the following code:
```
#define FOO(BAR) \
#BAR \
baz
```
gets minimized into:
```
#define FOO(BAR) #BAR baz
```
However, if there are no spaces before the backslash on line 2:
```
#define FOO(BAR) \
#BAR\
baz
```
no space can be preserved, leading to (most likely) malformed macro definition:
```
#define FOO(BAR) #BARbaz
```
This patch makes sure we always put exactly one space at the end of line ending with a backslash.
Reviewed By: arphaman
Differential Revision: https://reviews.llvm.org/D119231
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
Previously, the Framework name was only set if the file
came from a header mapped framework; now we'll always
set the framework name if the file is in a framework.
Differential Revision: https://reviews.llvm.org/D117830
Normally there are heruistics in lexer to treat `//*` specially in
language modes that don't have line comments (to emit `/`). Unfortunately this
only applied to the first occurence of a line comment inside the file, as the
subsequent line comments were treated as if language had support for them.
This unfortunately only holds in normal lexing mode, as in raw mode all
occurences of line comments received this treatment, which created discrepancies
when comparing expanded and spelled tokens.
The proper fix would be to just make sure we treat all the line comments with a
subsequent `*` the same way, but it would imply breaking some code that's
accepted by clang today. So instead we introduce the same bug into raw lexing
mode.
Fixes https://github.com/clangd/clangd/issues/1003.
Differential Revision: https://reviews.llvm.org/D118471
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
In D116750, the `clangFrontend` library was added as a dependency of `LexTests` in order to make `clang::ApplyHeaderSearchOptions()` available. This increased the number of TUs the test depends on.
This patch moves the function into `clangLex` and removes dependency of `LexTests` on `clangFrontend`.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D117024
The elements of `SearchPath::SearchDirs` are being referenced to by their indices. This proved to be error-prone: `HeaderSearch::SearchDirToHSEntry` was accidentally not being updated in `HeaderSearch::AddSearchPath()`. This patch fixes that by referencing `SearchPath::SearchDirs` elements by their address instead, which is stable thanks to the bump-ptr-allocation strategy.
Reviewed By: ahoppen
Differential Revision: https://reviews.llvm.org/D116750
Clang will now search through the framework includes to identify
the framework include path to a file, and then suggest a framework
style include spelling for the file.
Differential Revision: https://reviews.llvm.org/D115183
The #pragma directives push_macro/pop_macro and include_alias may influence the #include / import directives encountered by dependency scanning tools like clang-scan-deps.
This patch ensures that those directives are not removed during source code minimization.
Differential Revision: https://reviews.llvm.org/D112088
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
When building frameworks, headermaps responsible for mapping angle-included headers to their source file location are passed via
`-I` and not `-index-header-map`. Also, `-index-header-map` is only used for indexing purposes and not during most builds.
This patch holds on to the framework's name in HeaderFileInfo as this is retrieveable for cases outside of IndexHeaderMaps and
still represents the framework that is being built.
resolves: rdar://84046893
Reviewed By: jansvoboda11
Differential Revision: https://reviews.llvm.org/D111468
When the end loc of the specified range is a split token, `makeFileCharRange`
does not process it correctly. This patch adds proper support for split tokens.
Differential Revision: https://reviews.llvm.org/D105365
Original commit message:
[clang-repl] Implement partial translation units and error recovery.
https://reviews.llvm.org/D96033 contained a discussion regarding efficient
modeling of error recovery. @rjmccall has outlined the key ideas:
Conceptually, we can split the translation unit into a sequence of partial
translation units (PTUs). Every declaration will be associated with a unique PTU
that owns it.
The first key insight here is that the owning PTU isn't always the "active"
(most recent) PTU, and it isn't always the PTU that the declaration
"comes from". A new declaration (that isn't a redeclaration or specialization of
anything) does belong to the active PTU. A template specialization, however,
belongs to the most recent PTU of all the declarations in its signature - mostly
that means that it can be pulled into a more recent PTU by its template
arguments.
The second key insight is that processing a PTU might extend an earlier PTU.
Rolling back the later PTU shouldn't throw that extension away. For example, if
the second PTU defines a template, and the third PTU requires that template to
be instantiated at float, that template specialization is still part of the
second PTU. Similarly, if the fifth PTU uses an inline function belonging to the
fourth, that definition still belongs to the fourth. When we go to emit code in
a new PTU, we map each declaration we have to emit back to its owning PTU and
emit it in a new module for just the extensions to that PTU. We keep track of
all the modules we've emitted for a PTU so that we can unload them all if we
decide to roll it back.
Most declarations/definitions will only refer to entities from the same or
earlier PTUs. However, it is possible (primarily by defining a
previously-declared entity, but also through templates or ADL) for an entity
that belongs to one PTU to refer to something from a later PTU. We will have to
keep track of this and prevent unwinding to later PTU when we recognize it.
Fortunately, this should be very rare; and crucially, we don't have to do the
bookkeeping for this if we've only got one PTU, e.g. in normal compilation.
Otherwise, PTUs after the first just need to record enough metadata to be able
to revert any changes they've made to declarations belonging to earlier PTUs,
e.g. to redeclaration chains or template specialization lists.
It should even eventually be possible for PTUs to provide their own slab
allocators which can be thrown away as part of rolling back the PTU. We can
maintain a notion of the active allocator and allocate things like Stmt/Expr
nodes in it, temporarily changing it to the appropriate PTU whenever we go to do
something like instantiate a function template. More care will be required when
allocating declarations and types, though.
We would want the PTU to be efficiently recoverable from a Decl; I'm not sure
how best to do that. An easy option that would cover most declarations would be
to make multiple TranslationUnitDecls and parent the declarations appropriately,
but I don't think that's good enough for things like member function templates,
since an instantiation of that would still be parented by its original class.
Maybe we can work this into the DC chain somehow, like how lexical DCs are.
We add a different kind of translation unit `TU_Incremental` which is a
complete translation unit that we might nonetheless incrementally extend later.
Because it is complete (and we might want to generate code for it), we do
perform template instantiation, but because it might be extended later, we don't
warn if it declares or uses undefined internal-linkage symbols.
This patch teaches clang-repl how to recover from errors by disconnecting the
most recent PTU and update the primary PTU lookup tables. For instance:
```./clang-repl
clang-repl> int i = 12; error;
In file included from <<< inputs >>>:1:
input_line_0:1:13: error: C++ requires a type specifier for all declarations
int i = 12; error;
^
error: Parsing failed.
clang-repl> int i = 13; extern "C" int printf(const char*,...);
clang-repl> auto r1 = printf("i=%d\n", i);
i=13
clang-repl> quit
```
Differential revision: https://reviews.llvm.org/D104918
This reverts commit 6775fc6ffa.
It also reverts "[lldb] Fix compilation by adjusting to the new ASTContext signature."
This reverts commit 03a3f86071.
We see some failures on the lldb infrastructure, these changes might play a role
in it. Let's revert it now and see if the bots will become green.
Ref: https://reviews.llvm.org/D104918
https://reviews.llvm.org/D96033 contained a discussion regarding efficient
modeling of error recovery. @rjmccall has outlined the key ideas:
Conceptually, we can split the translation unit into a sequence of partial
translation units (PTUs). Every declaration will be associated with a unique PTU
that owns it.
The first key insight here is that the owning PTU isn't always the "active"
(most recent) PTU, and it isn't always the PTU that the declaration
"comes from". A new declaration (that isn't a redeclaration or specialization of
anything) does belong to the active PTU. A template specialization, however,
belongs to the most recent PTU of all the declarations in its signature - mostly
that means that it can be pulled into a more recent PTU by its template
arguments.
The second key insight is that processing a PTU might extend an earlier PTU.
Rolling back the later PTU shouldn't throw that extension away. For example, if
the second PTU defines a template, and the third PTU requires that template to
be instantiated at float, that template specialization is still part of the
second PTU. Similarly, if the fifth PTU uses an inline function belonging to the
fourth, that definition still belongs to the fourth. When we go to emit code in
a new PTU, we map each declaration we have to emit back to its owning PTU and
emit it in a new module for just the extensions to that PTU. We keep track of
all the modules we've emitted for a PTU so that we can unload them all if we
decide to roll it back.
Most declarations/definitions will only refer to entities from the same or
earlier PTUs. However, it is possible (primarily by defining a
previously-declared entity, but also through templates or ADL) for an entity
that belongs to one PTU to refer to something from a later PTU. We will have to
keep track of this and prevent unwinding to later PTU when we recognize it.
Fortunately, this should be very rare; and crucially, we don't have to do the
bookkeeping for this if we've only got one PTU, e.g. in normal compilation.
Otherwise, PTUs after the first just need to record enough metadata to be able
to revert any changes they've made to declarations belonging to earlier PTUs,
e.g. to redeclaration chains or template specialization lists.
It should even eventually be possible for PTUs to provide their own slab
allocators which can be thrown away as part of rolling back the PTU. We can
maintain a notion of the active allocator and allocate things like Stmt/Expr
nodes in it, temporarily changing it to the appropriate PTU whenever we go to do
something like instantiate a function template. More care will be required when
allocating declarations and types, though.
We would want the PTU to be efficiently recoverable from a Decl; I'm not sure
how best to do that. An easy option that would cover most declarations would be
to make multiple TranslationUnitDecls and parent the declarations appropriately,
but I don't think that's good enough for things like member function templates,
since an instantiation of that would still be parented by its original class.
Maybe we can work this into the DC chain somehow, like how lexical DCs are.
We add a different kind of translation unit `TU_Incremental` which is a
complete translation unit that we might nonetheless incrementally extend later.
Because it is complete (and we might want to generate code for it), we do
perform template instantiation, but because it might be extended later, we don't
warn if it declares or uses undefined internal-linkage symbols.
This patch teaches clang-repl how to recover from errors by disconnecting the
most recent PTU and update the primary PTU lookup tables. For instance:
```./clang-repl
clang-repl> int i = 12; error;
In file included from <<< inputs >>>:1:
input_line_0:1:13: error: C++ requires a type specifier for all declarations
int i = 12; error;
^
error: Parsing failed.
clang-repl> int i = 13; extern "C" int printf(const char*,...);
clang-repl> auto r1 = printf("i=%d\n", i);
i=13
clang-repl> quit
```
Differential revision: https://reviews.llvm.org/D104918
Allow a preprocessor observer to be notified of mark pragmas. Although
this does not impact code generation in any way, it is useful for other
clients, such as clangd, to be able to identify any marked regions.
Reviewed By: dgoldman
Differential Revision: https://reviews.llvm.org/D105368
Summary:
suggestPathToFileForDiagnostics is actively used in clangd for converting
an absolute path to a header file to a header name as it should be spelled
in the sources. Current approach converts absolute path to relative path.
This diff implements missing logic that makes a reverse lookup from the
relative path to the key in the header map that should be used in the sources.
Prerequisite diff: https://reviews.llvm.org/D103229
Test Plan: check-clang
Reviewers: dexonsmith, bruno, rsmith
Subscribers: cfe-commits
Tasks:
Tags: #clang
Differential Revision: https://reviews.llvm.org/D103142
WG14 adopted N2645 and WG21 EWG has accepted P2334 in principle (still
subject to full EWG vote + CWG review + plenary vote), which add
support for #elifdef as shorthand for #elif defined and #elifndef as
shorthand for #elif !defined. This patch adds support for the new
preprocessor directives.
Summary:
Macro argument expansion logic relies on skipping file IDs that created
as a result of an include. Unfortunately it fails to do that for
predefined buffer since it doesn't have a valid insertion location.
As a result of that any file ID created for an include inside the
predefined buffers breaks the traversal logic in
SourceManager::computeMacroArgsCache.
To fix this issue we first record number of created FIDs for predefined
buffer, and then skip them explicitly in source manager.
Another solution would be to just give predefined buffers a valid source
location, but it is unclear where that should be..
Reviewers: sammccall
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D78649
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.
This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.
This doesn't actually modify StringRef yet, I'll do that in a follow-up.
This patch makes the minimizer more conservative to avoid missing dependency files that are brought in by __has_include
PP expressions that occur in a condition of an #if/#elif that was previously skipped. The __has_include PP expressions
can be used in an #if/#elif either directly, or through macro expansion, so we can't detect them at the time of minimization.
Differential Revision: https://reviews.llvm.org/D70936
The existing string/character literal skipping code in the
dependency directives source minimizer has two issues:
- It doesn't stop the scanning when a newline is reached before the terminating character,
unlike the lexer which considers the token to be done (even if it's invalid) at the end of the line.
- It doesn't support whitespace between '\' and the newline when looking if the '\' is used as a line continuation character.
This commit fixes both issues.
Differential Revision: https://reviews.llvm.org/D68436
llvm-svn: 374127
in the dependency source minimizer
Clang allows continuations that have whitespace between the backslash and the newline.
This patch ensures that the dependency source minimizer can handle the whitespace between
the backslash and the newline when looking for a line continuation.
Differential Revision: https://reviews.llvm.org/D68052
llvm-svn: 373007
In case of certain #define'd macros, there's a space just before line continuation
that the minimized-source lexer was missing to include, resulting in invalid stringize.
Patch by: kousikk (Kousik Kumar)
Differential Revision: https://reviews.llvm.org/D67635
llvm-svn: 372360
This commit adds an optimization to clang-scan-deps and clang's preprocessor that skips excluded preprocessor
blocks by bumping the lexer pointer, and not lexing the tokens until reaching appropriate #else/#endif directive.
The skip positions and lexer offsets are computed when the file is minimized, directly from the minimized tokens.
On an 18-core iMacPro with macOS Catalina Beta I got 10-15% speed-up from this optimization when running clang-scan-deps on
the compilation database for a recent LLVM and Clang (3511 files).
Differential Revision: https://reviews.llvm.org/D67127
llvm-svn: 371656
accessed name to the directory entry
This commit introduces a parallel API that returns a DirectoryEntryRef
to the FileManager, similar to the parallel FileEntryRef API. All
uses will have to be update in follow-up patches. The immediate use of the new API in this
patch fixes the issue where a file manager was reused in clang-scan-deps,
but reported an different file path whenever a framework lookup was done through a symlink.
Differential Revision: https://reviews.llvm.org/D67026
llvm-svn: 370562
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.
Differential revision: https://reviews.llvm.org/D66259
llvm-svn: 368942
Update the callers of FileManager::getFile and FileManager::getDirectory to handle the new llvm::ErrorOr-returning methods.
Signed-off-by: Harlan Haskins <harlan@apple.com>
llvm-svn: 367616
Summary:
The cache recorded the wrong expansion location for all but the first
stringization. It seems uncommon to stringize the same macro argument
multiple times, so this cache doesn't seem that important.
Fixes PR39942
Reviewers: vsk, rsmith
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D65428
llvm-svn: 367337
We should re-emit `#pragma once` to ensure the preprocessor will
still honor it when running on minimized sources.
Differential Revision: https://reviews.llvm.org/D64945
llvm-svn: 366509
single quotes are not digit separators after a valid character literal prefix
The single quote character can act as a c++ digit separator.
However, the minimizer shouldn't treat it as such when it's actually following
a valid character literal prefix, like L, U, u, or u8.
Differential Revision: https://reviews.llvm.org/D64525
llvm-svn: 365700
Summary:
Currently HeaderSearch only looks at SearchDir's passed into it, but in
addition to those paths headers can be relative to including file's directory.
This patch makes sure that is taken into account.
Reviewers: gribozavr
Subscribers: jkorous, arphaman, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D63295
llvm-svn: 365005
r362459 introduced DependencyDirectivesSourceMinimizerTest.cpp, which
hits an MSVC bug:
developercommunity.visualstudio.com/content/problem/67300/stringifying-raw-string-literal.html
This only happens when the parameter to a macro is stringified in the
macro. This patch removes the string from the assert so that the
warning no longer happens.
llvm-svn: 363074
that might affect the dependency list for a compilation
This commit introduces a dependency directives source minimizer to clang
that minimizes header and source files to the minimum necessary preprocessor
directives for evaluating includes. It reduces the source down to #define, #include,
The source minimizer works by lexing the input with a custom fast lexer that recognizes
the preprocessor directives it cares about, and emitting those directives in the minimized source.
It ignores source code, comments, and normalizes whitespace. It gives up and fails if seems
any directives that it doesn't recognize as valid (e.g. #define 0).
In addition to the source minimizer this patch adds a
-print-dependency-directives-minimized-source CC1 option that allows you to invoke the minimizer
from clang directly.
Differential Revision: https://reviews.llvm.org/D55463
llvm-svn: 362459
Summary:
Include insertion in clangd was inserting absolute paths when the
include directory was an absolute path with a double dot. This patch makes sure
double dots are handled both with absolute and relative paths.
Reviewers: sammccall
Subscribers: ilya-biryukov, ioeric, jkorous, arphaman, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D60873
llvm-svn: 359078
It now comes with a follow-up fix for the clients of this API
in clangd and clang-tidy.
Differential Revision: https://reviews.llvm.org/D59977
llvm-svn: 359035
As the unit test demonstrates, subtracting 1 from the offset was unnecessary.
The only user of this function was the plist file emitter (in Static Analyzer
and ARCMigrator). It means that a lot of Static Analyzer's plist arrows
are in fact off by one character. The patch carefully preserves this
completely incorrect behavior and causes no functional change,
i.e. no plist format breakage.
Differential Revision: https://reviews.llvm.org/D59977
llvm-svn: 357823
Change MemoryBufferCache to InMemoryModuleCache, moving it from Basic to
Serialization. Another patch will start using it to manage module build
more explicitly, but this is split out because it's mostly mechanical.
Because of the move to Serialization we can no longer abuse the
Preprocessor to forward it to the ASTReader. Besides the rename and
file move, that means Preprocessor::Preprocessor has one fewer parameter
and ASTReader::ASTReader has one more.
llvm-svn: 355777
Jan Svoboda