Commit Graph

127 Commits

Author SHA1 Message Date
Alex Lorenz 389530524b [clang-scan-deps] do not skip empty #if/#elif in the minimizer to avoid missing `__has_include` dependencies
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
2019-12-02 18:47:22 -08:00
Alex Lorenz a13f0da1d0 [clang-scan-deps] Improve string/character literal skipping
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
2019-10-08 22:42:44 +00:00
Utkarsh Saxena edf5027689 [clang] Add test for FindNextToken in Lexer.
Reviewers: ilya-biryukov

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D68565

llvm-svn: 373910
2019-10-07 14:20:46 +00:00
Alex Lorenz 15d5f5dd35 [clang-scan-deps] Allow continuation line backslashes followed by whitespace
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
2019-09-26 19:28:51 +00:00
Alex Lorenz ccf8d5b829 Fix for stringized function-macro args continued across lines
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
2019-09-19 22:39:24 +00:00
Alex Lorenz ca6e60971e [clang-scan-deps] add skip excluded conditional preprocessor block preprocessing optimization
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
2019-09-11 20:40:31 +00:00
Alex Lorenz 0377ca641c Introduce a DirectoryEntryRef that stores both a reference and an
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
2019-08-31 01:26:04 +00:00
Jonas Devlieghere 2b3d49b610 [Clang] Migrate llvm::make_unique to std::make_unique
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
2019-08-14 23:04:18 +00:00
Michael J. Spencer 1861f4ea25 [clang-scan-deps] Add minimizer support for C++20 modules.
This only adds support to the minimizer, it doesn't actually capture the dependencies yet.

llvm-svn: 368381
2019-08-09 02:01:10 +00:00
Harlan Haskins 8d323d1506 [clang] Adopt new FileManager error-returning APIs
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
2019-08-01 21:31:56 +00:00
Reid Kleckner c0e275df3d Remove cache for macro arg stringization
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
2019-07-30 17:58:22 +00:00
Alex Lorenz 4cd905bdc1 [clang-scan-deps] Dependency directives source minimizer: handle #pragma once
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
2019-07-18 22:33:14 +00:00
Alex Lorenz 9a6c17b5b8 [clang-scan-deps] Dependency directives source minimizer:
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
2019-07-10 22:00:59 +00:00
Tom Stellard 2e97d2aa1b cmake: Add CLANG_LINK_CLANG_DYLIB option
Summary:
Setting CLANG_LINK_CLANG_DYLIB=ON causes clang tools to link against
libclang_shared.so instead of the individual component libraries.

Reviewers: mgorny, beanz, smeenai, phosek, sylvestre.ledru

Subscribers: arphaman, cfe-commits, llvm-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D63503

llvm-svn: 365092
2019-07-03 22:45:55 +00:00
Kadir Cetinkaya 1f6d9845d8 [clang][HeaderSearch] Shorten paths for includes in mainfile's directory
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
2019-07-03 07:47:19 +00:00
Erich Keane d65ef6735a Fix for r42230, MSVC test failure in DependencyDirectivesSourceMinimizerTest.cpp
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
2019-06-11 14:58:26 +00:00
Kadir Cetinkaya 51f85b40bc [clang][HeaderSearch] Consider all path separators equal
Reviewers: ilya-biryukov, sammccall

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D62965

llvm-svn: 362731
2019-06-06 18:49:16 +00:00
Alex Lorenz 6e2d36b60b Add clang source minimizer that reduces source to directives
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
2019-06-03 22:59:17 +00:00
Kadir Cetinkaya 936c67d3ef [clang][HeaderSuggestion] Handle the case of dotdot with an absolute path
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
2019-04-24 09:23:31 +00:00
Kadir Cetinkaya 40f8f7f95c [clang][HeaderSearch] Make sure there are no backslashes in suggestedPath
Reviewers: sammccall

Differential Revision: https://reviews.llvm.org/D60995

llvm-svn: 359075
2019-04-24 08:45:03 +00:00
Artem Dergachev 8c099ce72d Re-apply r357823 "[Lexer] NFC: Fix an off-by-one bug in getAsCharRange()."
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
2019-04-23 21:15:26 +00:00
Artem Dergachev 4a9007cde7 Revert "[Lexer] NFC: Fix an off-by-one bug in getAsCharRange()."
This reverts commit r357823.

Was breaking clang-tidy!

Differential Revision: https://reviews.llvm.org/D59977

llvm-svn: 357827
2019-04-05 22:11:28 +00:00
Artem Dergachev 1dfd74ac4a [Lexer] NFC: Fix an off-by-one bug in getAsCharRange().
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
2019-04-05 21:48:52 +00:00
Duncan P. N. Exon Smith 8bef5cd49a Modules: Rename MemoryBufferCache to InMemoryModuleCache
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
2019-03-09 17:33:56 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Reid Kleckner 35c537490f Fix -Wsign-compare in new tests
llvm-svn: 351478
2019-01-17 20:52:46 +00:00
Aaron Ballman 65e96bdaca Revert r351209 (which was a revert of r350891) with a fix.
The test case had a parse error that was causing the condition string to be misreported. We now have better fallback code for error cases.

llvm-svn: 351470
2019-01-17 20:21:34 +00:00
Benjamin Kramer d4d77343e5 Revert "Correct the source range returned from preprocessor callbacks."
This reverts commit r350891. Also add a test case that would return an
empty string with r350891.

llvm-svn: 351209
2019-01-15 17:20:05 +00:00
Bjorn Pettersson 03c9f684d8 Silence -Wsign-compare in unittests
llvm-svn: 350933
2019-01-11 16:53:45 +00:00
Aaron Ballman 70bdcdf55d Correct the source range returned from preprocessor callbacks.
This adjusts the source range passed in to the preprocessor callbacks to only include the condition range itself, rather than all of the conditionally skipped tokens.

llvm-svn: 350891
2019-01-10 21:22:13 +00:00
Jonas Devlieghere fc51490baf Lift VFS from clang to llvm (NFC)
This patch moves the virtual file system form clang to llvm so it can be
used by more projects.

Concretely the patch:
 - Moves VirtualFileSystem.{h|cpp} from clang/Basic to llvm/Support.
 - Moves the corresponding unit test from clang to llvm.
 - Moves the vfs namespace from clang::vfs to llvm::vfs.
 - Formats the lines affected by this change, mostly this is the result of
   the added llvm namespace.

RFC on the mailing list:
http://lists.llvm.org/pipermail/llvm-dev/2018-October/126657.html

Differential revision: https://reviews.llvm.org/D52783

llvm-svn: 344140
2018-10-10 13:27:25 +00:00
Julie Hockett 96fbe58b0f Reland '[clang] Adding CharacteristicKind to PPCallbacks::InclusionDirective'
This commit relands r331904.

Adding a SrcMgr::CharacteristicKind parameter to the InclusionDirective
in PPCallbacks, and updating calls to that function. This will be useful
in https://reviews.llvm.org/D43778 to determine which includes are
system
headers.

Differential Revision: https://reviews.llvm.org/D46614

llvm-svn: 332021
2018-05-10 19:05:36 +00:00
Julie Hockett b524d5e553 Revert "[clang] Adding CharacteristicKind to PPCallbacks::InclusionDirective"
This reverts commit r331904 because of a memory leak.

llvm-svn: 331932
2018-05-09 22:25:47 +00:00
Julie Hockett 36d94ab8f0 [clang] Adding CharacteristicKind to PPCallbacks::InclusionDirective
Adding a SrcMgr::CharacteristicKind parameter to the InclusionDirective
in PPCallbacks, and updating calls to that function. This will be useful
in https://reviews.llvm.org/D43778 to determine which includes are system
headers.

Differential Revision: https://reviews.llvm.org/D46614

llvm-svn: 331904
2018-05-09 18:27:33 +00:00
Richard Smith b5f8171a1b PR37189 Fix incorrect end source location and spelling for a split '>>' token.
When a '>>' token is split into two '>' tokens (in C++11 onwards), or (as an
extension) when we do the same for other tokens starting with a '>', we can't
just use a location pointing to the first '>' as the location of the split
token, because that would result in our miscomputing the length and spelling
for the token. As a consequence, for example, a refactoring replacing 'A<X>'
with something else would sometimes replace one character too many, and
similarly diagnostics highlighting a template-id source range would highlight
one character too many.

Fix this by creating an expansion range covering the first character of the
'>>' token, whose spelling is '>'. For this to work, we generalize the
expansion range of a macro FileID to be either a token range (the common case)
or a character range (used in this new case).

llvm-svn: 331155
2018-04-30 05:25:48 +00:00
Eric Liu dffb1a806c [Lexer] Support adding working directory to relative search dir for #include shortening in HeaderSearch.
Reviewers: bkramer

Subscribers: mgorny, hintonda, cfe-commits

Differential Revision: https://reviews.llvm.org/D42577

llvm-svn: 323647
2018-01-29 13:21:23 +00:00
Volodymyr Sapsai abb8dfc114 [Lex] Avoid out-of-bounds dereference in LexAngledStringLiteral.
Fix makes the loop in LexAngledStringLiteral more like the loops in
LexStringLiteral, LexCharConstant. When we skip a character after
backslash, we need to check if we reached the end of the file instead of
reading the next character unconditionally.

Discovered by OSS-Fuzz:
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=3832

rdar://problem/35572754

Reviewers: arphaman, kcc, rsmith, dexonsmith

Reviewed By: rsmith, dexonsmith

Subscribers: cfe-commits, rsmith, dexonsmith

Differential Revision: https://reviews.llvm.org/D41423

llvm-svn: 322390
2018-01-12 18:54:35 +00:00
Volodymyr Sapsai cbafa59527 [Lex] Inline a variable in test in preparation for more similar tests. NFC.
llvm-svn: 322240
2018-01-10 23:37:29 +00:00
Taewook Oh cebac48bf7 Stringizing raw string literals containing newline
Summary: This patch implements 4.3 of http://open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4220.pdf. If a raw string contains a newline character, replace each newline character with the \n escape code. Without this patch, included test case (macro_raw_string.cpp) results compilation failure.

Reviewers: rsmith, doug.gregor, jkorous-apple

Reviewed By: jkorous-apple

Subscribers: jkorous-apple, vsapsai, cfe-commits

Differential Revision: https://reviews.llvm.org/D39279

llvm-svn: 319904
2017-12-06 17:00:53 +00:00
Shoaib Meenai d806af3499 [CMake] Use PRIVATE in target_link_libraries for executables
We currently use target_link_libraries without an explicit scope
specifier (INTERFACE, PRIVATE or PUBLIC) when linking executables.
Dependencies added in this way apply to both the target and its
dependencies, i.e. they become part of the executable's link interface
and are transitive.

Transitive dependencies generally don't make sense for executables,
since you wouldn't normally be linking against an executable. This also
causes issues for generating install export files when using
LLVM_DISTRIBUTION_COMPONENTS. For example, clang has a lot of LLVM
library dependencies, which are currently added as interface
dependencies. If clang is in the distribution components but the LLVM
libraries it depends on aren't (which is a perfectly legitimate use case
if the LLVM libraries are being built static and there are therefore no
run-time dependencies on them), CMake will complain about the LLVM
libraries not being in export set when attempting to generate the
install export file for clang. This is reasonable behavior on CMake's
part, and the right thing is for LLVM's build system to explicitly use
PRIVATE dependencies for executables.

Unfortunately, CMake doesn't allow you to mix and match the keyword and
non-keyword target_link_libraries signatures for a single target; i.e.,
if a single call to target_link_libraries for a particular target uses
one of the INTERFACE, PRIVATE, or PUBLIC keywords, all other calls must
also be updated to use those keywords. This means we must do this change
in a single shot. I also fully expect to have missed some instances; I
tested by enabling all the projects in the monorepo (except dragonegg),
and configuring both with and without shared libraries, on both Darwin
and Linux, but I'm planning to rely on the buildbots for other
configurations (since it should be pretty easy to fix those).

Even after this change, we still have a lot of target_link_libraries
calls that don't specify a scope keyword, mostly for shared libraries.
I'm thinking about addressing those in a follow-up, but that's a
separate change IMO.

Differential Revision: https://reviews.llvm.org/D40823

llvm-svn: 319840
2017-12-05 21:49:56 +00:00
Alex Lorenz d5bf436d3a [Lex] Avoid out-of-bounds dereference in SkipLineComment
Credit to OSS-Fuzz for discovery:
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=3145

rdar://34526482

llvm-svn: 315785
2017-10-14 01:18:30 +00:00
Alexander Kornienko cf007a7614 [Lexer] Finding beginning of token with escaped new line
Summary:
Lexer::GetBeginningOfToken produced invalid location when
backtracking across escaped new lines.

This fixes PR26228

Reviewers: akyrtzi, alexfh, rsmith, doug.gregor

Reviewed By: alexfh

Subscribers: alexfh, cfe-commits

Patch by Paweł Żukowski!

Differential Revision: https://reviews.llvm.org/D30748

llvm-svn: 310576
2017-08-10 10:06:16 +00:00
Faisal Vali ac506d7494 [NFC] Refactor the Preprocessor function that handles Macro definitions and rename Arguments to Parameters in Macro Definitions.
- Extracted the reading of the tokens out into a separate function.
  - Replace 'Argument' with 'Parameter' when referring to the identifiers of the macro definition (as opposed to the supplied arguments - MacroArgs - during the macro invocation).

This is in preparation for submitting patches for review to implement __VA_OPT__ which will otherwise just keep lengthening the HandleDefineDirective function and making it less comprehensible.

I will also directly update some extra clang tooling that is broken by the change from Argument to Parameter.

Hopefully the bots will stay appeased.

Thanks!

llvm-svn: 308190
2017-07-17 17:18:43 +00:00
Faisal Vali 0e54e5679e Revert changes from my previous refactoring - will need to fix dependencies in clang's extra tooling (such as clang-tidy etc.).
Sorry about that.

llvm-svn: 308158
2017-07-17 02:03:21 +00:00
Faisal Vali 11746b05e5 [NFC] Refactor the Preprocessor function that handles Macro definitions and rename Arguments to Parameters in Macro Definitions.
- Extracted the reading of the tokens out into a separate function.
  - Replace 'Argument' with 'Parameter' when referring to the identifiers of the macro definition (as opposed to the supplied arguments - MacroArgs - during the macro invocation).

This is in preparation for submitting patches for review to implement __VA_OPT__ which will otherwise just keep lengthening the HandleDefineDirective function and making it less comprehensible.


Thanks!

llvm-svn: 308157
2017-07-17 01:27:53 +00:00
Erich Keane cb7af85b90 LexerTest memory leak fix-
A new LexerTest unittest introduced a memory leak.  This patch
uses a unique_ptr with a custom deleter to ensure it is properly
deleted.

llvm-svn: 305491
2017-06-15 18:34:47 +00:00
Erich Keane dfa02b5491 Fix LexerTest signed/unsigned comparison.
Werror was catching a signed/unsigned compare in 
an assert, correct the signed 'expected' value to be
unsigned.

llvm-svn: 305435
2017-06-15 00:28:13 +00:00
Erich Keane 8691d6e678 [Preprocessor]Correct Macro-Arg allocation of StringifiedArguments,
correct getNumArguments

StringifiedArguments is allocated (resized) based on the size the 
getNumArguments function. However, this function ACTUALLY currently 
returns the amount of total UnexpArgTokens which is minimum the same as 
the new implementation of getNumMacroArguments, since empty/omitted arguments 
result in 1 UnexpArgToken, and included ones at minimum include 2 
(1 for the arg itself, 1 for eof).

This patch renames the otherwise unused getNumArguments to be more clear 
that it is the number of arguments that the Macro expects, and thus the maximum 
number that can be stringified. This patch also replaces the explicit memset 
(which results in value instantiation of the new tokens, PLUS clearing the 
memory) with brace initialization.

Differential Revision: https://reviews.llvm.org/D32046

llvm-svn: 305425
2017-06-14 23:09:01 +00:00
Richard Smith 5d2ed48987 Add #pragma clang module build/endbuild pragmas for performing a module build
as part of a compilation.

This is intended for two purposes:

1) Writing self-contained test cases for modules: we can now write a single
source file test that builds some number of module files on the side and
imports them.

2) Debugging / test case reduction. A single-source testcase is much more
amenable to reduction, compared to a VFS tarball or .pcm files.

llvm-svn: 305101
2017-06-09 19:22:32 +00:00
Duncan P. N. Exon Smith 030d7d6daa Reapply "Modules: Cache PCMs in memory and avoid a use-after-free"
This reverts commit r298185, effectively reapplying r298165, after fixing the
new unit tests (PR32338).  The memory buffer generator doesn't null-terminate
the MemoryBuffer it creates; this version of the commit informs getMemBuffer
about that to avoid the assert.

Original commit message follows:

----

Clang's internal build system for implicit modules uses lock files to
ensure that after a process writes a PCM it will read the same one back
in (without contention from other -cc1 commands).  Since PCMs are read
from disk repeatedly while invalidating, building, and importing, the
lock is not released quickly.  Furthermore, the LockFileManager is not
robust in every environment.  Other -cc1 commands can stall until
timeout (after about eight minutes).

This commit changes the lock file from being necessary for correctness
to a (possibly dubious) performance hack.  The remaining benefit is to
reduce duplicate work in competing -cc1 commands which depend on the
same module.  Follow-up commits will change the internal build system to
continue after a timeout, and reduce the timeout.  Perhaps we should
reconsider blocking at all.

This also fixes a use-after-free, when one part of a compilation
validates a PCM and starts using it, and another tries to swap out the
PCM for something new.

The PCMCache is a new type called MemoryBufferCache, which saves memory
buffers based on their filename.  Its ownership is shared by the
CompilerInstance and ModuleManager.

- The ModuleManager stores PCMs there that it loads from disk, never
touching the disk if the cache is hot.

- When modules fail to validate, they're removed from the cache.

- When a CompilerInstance is spawned to build a new module, each
already-loaded PCM is assumed to be valid, and is frozen to avoid
the use-after-free.

- Any newly-built module is written directly to the cache to avoid the
round-trip to the filesystem, making lock files unnecessary for
correctness.

Original patch by Manman Ren; most testcases by Adrian Prantl!

llvm-svn: 298278
2017-03-20 17:58:26 +00:00