Commit Graph

698 Commits

Author SHA1 Message Date
Jan Svoboda 78668c822a [clang][modules][pch] Allow loading PCH with different modules cache path
It's useful to be able to load explicitly-built PCH files into an implicit build (e.g. during dependency scanning). That's currently impossible, since the explicitly-built PCH has an empty modules cache path, while the current compilation has (and needs to have) a valid path, triggering an error in the `PCHValidator`.

This patch adds a preprocessor option and command-line flag that can be used to omit this check.

Reviewed By: dexonsmith

Differential Revision: https://reviews.llvm.org/D103802
2021-06-14 11:04:56 +02:00
Michael Spencer d3676d4b66 [clang][modules] Build inferred modules
This patch enables explicitly building inferred modules.

Effectively a cherry-pick of https://github.com/apple/llvm-project/pull/699 authored by @Bigcheese with libclang and dependency scanner changes omitted.

Contains the following changes:

1. [Clang] Fix the header paths in clang::Module for inferred modules.
  * The UmbrellaAsWritten and NameAsWritten fields in clang::Module are a lie for framework modules. For those they actually are the path to the header or umbrella relative to the clang::Module::Directory.
  * The exception to this case is for inferred modules. Here it actually is the name as written, because we print out the module and read it back in when implicitly building modules. This causes a problem when explicitly building an inferred module, as we skip the printing out step.
  * In order to fix this issue this patch adds a new field for the path we want to use in getInputBufferForModule. It also makes NameAsWritten actually be the name written in the module map file (or that would be, in the case of an inferred module).

2. [Clang] Allow explicitly building an inferred module.
  * Building the actual module still fails, but make sure it fails for the right reason.

Split from D100934.

Reviewed By: dexonsmith

Differential Revision: https://reviews.llvm.org/D102491
2021-05-17 10:40:51 +02:00
Ben Barham 1206b95e07 [ASTReader] Only mark module out of date if not already compiled
If a module contains errors (ie. it was built with
-fallow-pcm-with-compiler-errors and had errors) and was from the module
cache, it is marked as out of date - see
a2c1054c30.

When a module is imported multiple times in the one compile, this caused
it to be recompiled each time - removing the existing buffer from the
module cache and replacing it. This results in various errors further
down the line.

Instead, only mark the module as out of date if it isn't already
finalized in the module cache.

Reviewed By: akyrtzi

Differential Revision: https://reviews.llvm.org/D100619
2021-04-16 17:57:03 -07:00
Richard Smith 4259301aaf Support #__private_macro and #__public_macro in local submodule
visibility mode.
2021-03-23 16:54:28 -07:00
Ben Barham a2c1054c30 [ASTReader] Always rebuild a cached module that has errors
A module in the cache with an error should just be a cache miss. If
allowing errors (with -fallow-pcm-with-compiler-errors), a rebuild is
needed so that the appropriate diagnostics are output and in case search
paths have changed. If not allowing errors, the module was built
*allowing* errors and thus should be rebuilt regardless.

Reviewed By: akyrtzi

Differential Revision: https://reviews.llvm.org/D95989
2021-02-03 22:06:46 -08:00
Arthur O'Dwyer e181a6aedd s/instantate/instantiate/ throughout. NFCI.
The static_assert in "libcxx/include/memory" was the main offender here,
but then I figured I might as well `git grep -i instantat` and fix all
the instances I found. One was in user-facing HTML documentation;
the rest were in comments or tests.
2020-12-01 22:13:40 -05:00
Andrew Gallagher c6c8d4a13e [modules] Fix crash in call to `FunctionDecl::setPure()`
In some cases, when deserializing a `CXXMethodDecl` of a `CXXSpecializationTemplateDecl`,
the call to `FunctionDecl::setPure()` happens before the `DefinitionData` member has been
populated (which appears to happen lower down in a `mergeRedeclarable` call), causing a
crash (https://reviews.llvm.org/P8228).

This diff fixes this by deferring the `FunctionDecl::setPure()` till after the `DefinitionData` has
been filled in.

Reviewed By: lxfind

Differential Revision: https://reviews.llvm.org/D86853
2020-11-18 11:55:29 -08:00
Ben Barham 5834996fef [Frontend] Add flag to allow PCM generation despite compiler errors
As with precompiled headers, it's useful for indexers to be able to
continue through compiler errors in dependent modules.

Resolves rdar://69816264

Reviewed By: akyrtzi

Differential Revision: https://reviews.llvm.org/D91580
2020-11-17 17:27:50 -08:00
Alexandre Rames 58c586e701 Allow searching for prebuilt implicit modules.
This reverts commit c67656b994, and addresses the
build issue.
2020-11-10 10:14:13 -08:00
Stella Stamenova c67656b994 Revert "Allow searching for prebuilt implicit modules."
This reverts commit 71e108cd86.

This change caused a build failure on Windows:
http://lab.llvm.org:8011/#/builders/83/builds/570
2020-11-05 17:16:14 -08:00
Alexandre Rames 71e108cd86 Allow searching for prebuilt implicit modules.
The behavior is controlled by the `-fprebuilt-implicit-modules` option, and
allows searching for implicit modules in the prebuilt module cache paths.

The current command-line options for prebuilt modules do not allow to easily
maintain and use multiple versions of modules. Both the producer and users of
prebuilt modules are required to know the relationships between compilation
options and module file paths. Using a particular version of a prebuilt module
requires passing a particular option on the command line (e.g.
`-fmodule-file=[<name>=]<file>` or `-fprebuilt-module-path=<directory>`).

However the compiler already knows how to distinguish and automatically locate
implicit modules. Hence this proposal to introduce the
`-fprebuilt-implicit-modules` option. When set, it enables searching for
implicit modules in the prebuilt module paths (specified via
`-fprebuilt-module-path`). To not modify existing behavior, this search takes
place after the standard search for prebuilt modules. If not

Here is a workflow illustrating how both the producer and consumer of prebuilt
modules would need to know what versions of prebuilt modules are available and
where they are located.

  clang -cc1 -x c modulemap -fmodules -emit-module -fmodule-name=foo -fmodules-cache-path=prebuilt_modules_v1 <config 1 options>
  clang -cc1 -x c modulemap -fmodules -emit-module -fmodule-name=foo -fmodules-cache-path=prebuilt_modules_v2 <config 2 options>
  clang -cc1 -x c modulemap -fmodules -emit-module -fmodule-name=foo -fmodules-cache-path=prebuilt_modules_v3 <config 3 options>

  clang -cc1 -x c use.c -fmodules fmodule-map-file=modulemap -fprebuilt-module-path=prebuilt_modules_v1 <config 1 options>
  clang -cc1 -x c use.c -fmodules fmodule-map-file=modulemap <non-prebuilt config options>

With prebuilt implicit modules, the producer can generate prebuilt modules as
usual, all in the same output directory. The same mechanisms as for implicit
modules take care of incorporating hashes in the path to distinguish between
module versions.

Note that we do not specify the output module filename, so `-o` implicit modules are generated in the cache path `prebuilt_modules`.

  clang -cc1 -x c modulemap -fmodules -emit-module -fmodule-name=foo -fmodules-cache-path=prebuilt_modules <config 1 options>
  clang -cc1 -x c modulemap -fmodules -emit-module -fmodule-name=foo -fmodules-cache-path=prebuilt_modules <config 2 options>
  clang -cc1 -x c modulemap -fmodules -emit-module -fmodule-name=foo -fmodules-cache-path=prebuilt_modules <config 3 options>

The user can now simply enable prebuilt implicit modules and point to the
prebuilt modules cache. No need to "parse" command-line options to decide
what prebuilt modules (paths) to use.

  clang -cc1 -x c use.c -fmodules fmodule-map-file=modulemap -fprebuilt-module-path=prebuilt_modules -fprebuilt-implicit-modules <config 1 options>
  clang -cc1 -x c use.c -fmodules fmodule-map-file=modulemap -fprebuilt-module-path=prebuilt_modules -fprebuilt-implicit-modules <non-prebuilt config options>

This is for example particularly useful in a use-case where compilation is
expensive, and the configurations expected to be used are predictable, but not
controlled by the producer of prebuilt modules. Modules for the set of
predictable configurations can be prebuilt, and using them does not require
"parsing" the configuration (command-line options).

Reviewed By: Bigcheese

Differential Revision: https://reviews.llvm.org/D68997
2020-11-05 13:10:53 -08:00
Bill Wendling 34ca5b3392 Remove stale assert.
This is triggered during serialization. The test is for modules, but
will occur for any serialization effort using asm goto.

Reviewed By: nickdesaulniers, jyknight

Differential Revision: https://reviews.llvm.org/D88195
2020-09-24 13:59:42 -07:00
Raphael Isemann 105151ca56 Reland "Correctly emit dwoIDs after ASTFileSignature refactoring (D81347)"
The orignal patch with the missing 'REQUIRES: asserts' as there is a debug-only
flag used in the test.

Original summary:

D81347 changes the ASTFileSignature to be an array of 20 uint8_t instead of 5
uint32_t. However, it didn't update the code in ObjectFilePCHContainerOperations
that creates the dwoID in the module from the ASTFileSignature
(`Buffer->Signature` being the array subclass that is now `std::array<uint8_t,
20>` instead of `std::array<uint32_t, 5>`).

```
  uint64_t Signature = [..] (uint64_t)Buffer->Signature[1] << 32 | Buffer->Signature[0]
```

This code works with the old ASTFileSignature (where two uint32_t are enough to
fill the uint64_t), but after the patch this only took two bytes from the
ASTFileSignature and only partly filled the Signature uint64_t.

This caused that the dwoID in the module ref and the dwoID in the actual module
no longer match (which in turns causes that LLDB keeps warning about the dwoID's
not matching when debugging -gmodules-compiled binaries).

This patch just unifies the logic for turning the ASTFileSignature into an
uint64_t which makes the dwoID match again (and should prevent issues like that
in the future).

Reviewed By: aprantl, dang

Differential Revision: https://reviews.llvm.org/D84013
2020-08-24 14:52:53 +02:00
Raphael Isemann 2b3074c0d1 Revert "Reland "Correctly emit dwoIDs after ASTFileSignature refactoring (D81347)""
This reverts commit ada2e8ea67. Still breaking
on Fuchsia (and also Fedora) with exit code 1, so back to investigating.
2020-08-24 12:54:25 +02:00
Raphael Isemann ada2e8ea67 Reland "Correctly emit dwoIDs after ASTFileSignature refactoring (D81347)"
This relands D84013 but with a test that relies on less shell features to
hopefully make the test pass on Fuchsia (where the test from the previous patch
version strangely failed with a plain "Exit code 1").

Original summary:

D81347 changes the ASTFileSignature to be an array of 20 uint8_t instead of 5 uint32_t.
However, it didn't update the code in ObjectFilePCHContainerOperations that creates
the dwoID in the module from the ASTFileSignature (`Buffer->Signature` being the
array subclass that is now `std::array<uint8_t, 20>` instead of `std::array<uint32_t, 5>`).

```
  uint64_t Signature = [..] (uint64_t)Buffer->Signature[1] << 32 | Buffer->Signature[0]
```

This code works with the old ASTFileSignature  (where two uint32_t are enough to
fill the uint64_t), but after the patch this only took two bytes from the ASTFileSignature
and only partly filled the Signature uint64_t.

This caused that the dwoID in the module ref and the dwoID in the actual module no
longer match (which in turns causes that LLDB keeps warning about the dwoID's not
matching when debugging -gmodules-compiled binaries).

This patch just unifies the logic for turning the ASTFileSignature into an uint64_t which
makes the dwoID match again (and should prevent issues like that in the future).

Reviewed By: aprantl, dang

Differential Revision: https://reviews.llvm.org/D84013
2020-08-24 11:51:32 +02:00
Vaibhav Garg aca191cce1 Re-land 7a527f1777 with fixes.
The original commit was reverted in 58c305f466
due to broken bots. This commit corrects the triple and command line paths.
2020-08-21 14:40:09 -04:00
Aaron Ballman 58c305f466 Revert "Teach AttachPreviousImpl to inherit MSInheritanceAttr attribute"
This reverts commit 7a527f1777.

It caused some buildbot failures:
http://lab.llvm.org:8011/builders/clang-ppc64le-linux-multistage/builds/13600
http://lab.llvm.org:8011/builders/clang-cmake-armv7-quick/builds/20294
2020-08-21 12:42:10 -04:00
Vaibhav Garg 7a527f1777 Teach AttachPreviousImpl to inherit MSInheritanceAttr attribute
This commit teaches ASTDeclReader::attachPreviousDecl to successfully merge
two Decl's when one contains an inheritable attribute like the
MSInheritanceAttr. Usually, attributes that are needed to be present along the
redeclaration chain are attached during ASTReading from
ASTDeclReader::attachPreviousDecl, but no such thing is done for inheritable
attributes. Currently, only the logic for merging MSInheritanceAttr is
provided.
2020-08-21 12:04:43 -04:00
Raphael Isemann c1dd5df425 Revert "Correctly emit dwoIDs after ASTFileSignature refactoring (D81347)"
This reverts commit a4c3ed42ba.

The test is curiously failing with a plain exit code 1 on Fuchsia.
2020-08-21 16:08:37 +02:00
Raphael Isemann a4c3ed42ba Correctly emit dwoIDs after ASTFileSignature refactoring (D81347)
D81347 changes the ASTFileSignature to be an array of 20 uint8_t instead of 5
uint32_t. However, it didn't update the code in ObjectFilePCHContainerOperations
that creates the dwoID in the module from the ASTFileSignature
(`Buffer->Signature` being the array subclass that is now `std::array<uint8_t,
20>` instead of `std::array<uint32_t, 5>`).

```
  uint64_t Signature = [..] (uint64_t)Buffer->Signature[1] << 32 | Buffer->Signature[0]
```

This code works with the old ASTFileSignature (where two uint32_t are enough to
fill the uint64_t), but after the patch this only took two bytes from the
ASTFileSignature and only partly filled the Signature uint64_t.

This caused that the dwoID in the module ref and the dwoID in the actual module
no longer match (which in turns causes that LLDB keeps warning about the dwoID's
not matching when debugging -gmodules-compiled binaries).

This patch just unifies the logic for turning the ASTFileSignature into an
uint64_t which makes the dwoID match again (and should prevent issues like that
in the future).

Reviewed By: aprantl, dang

Differential Revision: https://reviews.llvm.org/D84013
2020-08-21 15:05:02 +02:00
Volodymyr Sapsai 7ac737e56b [HeaderSearch] Fix processing #import-ed headers multiple times with modules enabled.
HeaderSearch was marking requested HeaderFileInfo as Resolved only based on
the presence of ExternalSource. As the result, using any module was enough
to set ExternalSource and headers unknown to this module would have
HeaderFileInfo with empty fields, including `isImport = 0`, `NumIncludes = 0`.
Such HeaderFileInfo was preserved without changes regardless of how the
header was used in other modules and caused incorrect result in
`HeaderSearch::ShouldEnterIncludeFile`.

Fix by marking HeaderFileInfo as Resolved only if ExternalSource knows
about this header.

rdar://problem/62126911

Reviewed By: bruno

Differential Revision: https://reviews.llvm.org/D80263
2020-08-20 17:41:28 -07:00
Luboš Luňák 31b05692cd make -fmodules-codegen and -fmodules-debuginfo work also with PCHs
Allow to build PCH's (with -building-pch-with-obj and the extra .o file)
with -fmodules-codegen -fmodules-debuginfo to allow emitting shared code
into the extra .o file, similarly to how it works with modules. A bit of
a misnomer, but the underlying functionality is the same. This saves up
to 20% of build time here. The patch is fairly simple, it basically just
duplicates -fmodules checks to also alternatively check
-building-pch-with-obj.

This already got committed as cbc9d22e49,
but then got reverted in 7ea9a6e022
because of PR44953, as discussed in D74846. This is a corrected version
which does not include two places for the PCH case that aren't included
in the modules -fmodules-codegen path either.

Differential Revision: https://reviews.llvm.org/D69778
2020-07-09 15:22:26 +02:00
Richard Smith c32d261e27 Don't diagnose a redeclaration of a deduction guide if the prior
declaration is not visible.

In passing, add a test for a similar case of conflicting redeclarations
of internal-linkage structured bindings. (This case already works).
2020-06-12 10:29:01 -07:00
Daniel Grumberg bb8c7e756c Add AST_SIGNATURE record to unhashed control block of PCM files
Summary:
This record is constructed by hashing the bytes of the AST block in a similiar
fashion to the SIGNATURE record. This new signature only means anything if the
AST block is fully relocatable, i.e. it does not embed absolute offsets within
the PCM file. This change ensure this does not happen by replacing these offsets
with offsets relative to the nearest relevant subblock of the AST block.

Reviewers: Bigcheese, dexonsmith

Subscribers: dexonsmith, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D80383
2020-06-11 14:09:07 +01:00
Martin Boehme 8d74de9de6 [clang] Always allow including builtin headers in [no_undeclared_headers] modules.
Previously, this would fail if the builtin headers had been "claimed" by
a different module that wraps these builtin headers. libc++ does this,
for example.

This change adds a test demonstrating this situation; the test fails
without the fix.
2020-06-04 08:33:39 +02:00
Reid Kleckner bd6942eb21 Re-land "[MS] Fix assert handling enum forward decls in hasVisibleDefinition"
This reverts commit 9b2ab41037 and
reinstates e62dc1f625 with changes.

This fix is speculative, since I don't have access to a crashing test
case for the old code, and fixing the crash bug on Windows when C++20 is
enabled seems more important than running it down.
2020-04-23 16:22:01 -07:00
Rumeet Dhindsa 9b2ab41037 Revert "[MS] Fix assert handling enum forward decls in hasVisibleDefinition"
This reverts commit e62dc1f625.

Reverting as per discussion with the patch author.
This patch causes module import error, but there was no intended
behavior change for code that does not use Microsoft extensions.
2020-04-20 10:40:27 -07:00
Richard Smith 6bc7502385 When making modules transitively visible, don't take into account
whether they have missing header files.

Whether a module's headers happen to be present on the local file system
should make no difference to whether we make its contents visible when
importing another module that re-exports it. If we have an up-to-date
AST file that we can load, that's all that matters.

This fixes the ability to header syntax checking for modular headers in
C++20 mode (or in prior modes where -fmodules-local-submodule-visibility
is enabled but -fmodules is not).
2020-04-17 22:49:58 -07:00
Reid Kleckner e62dc1f625 [MS] Fix assert handling enum forward decls in hasVisibleDefinition
An enum may be considered to be a complete type if it was forward
declared. It may be declared with a fixed underlying type, or, in MSVC
compatiblity mode, with no type at all.

Previously, the code was written with special handling for fixed enums.
I generalized the code to check if the underlying integer type is known,
which should be the case when targetting the MSVC C++ ABI.

Fixes PR45409
2020-04-03 16:46:07 -07:00
Rumeet Dhindsa 57a2eaf3c1 Revert "[modules] Do not cache invalid state for modules that we attempted to load."
As per comment on https://reviews.llvm.org/D72860, it is suggested to
revert this change in the meantime, since it has introduced regression.

This reverts commit 83f4c3af02.
2020-03-10 10:59:26 -07:00
Volodymyr Sapsai 4069dd1412 [modules] Allow frameworks to have only a private module without a public one.
Support only preferred spelling 'Modules/module.private.modulemap' and
not the deprecated 'module_private.map'.

rdar://problem/57715533

Reviewed By: bruno

Differential Revision: https://reviews.llvm.org/D75311
2020-02-28 15:40:24 -08:00
Hans Wennborg 7ea9a6e022 Revert "make -fmodules-codegen and -fmodules-debuginfo work also with PCHs"
This caused PR44953. See also the discussion on D74846.

This reverts commit cbc9d22e49.
2020-02-27 14:33:43 +01:00
John McCall 77b2ffc498 Fix a reentrance bug with deserializing ObjC type parameters.
This is a longstanding bug that seems to have been hidden by
a combination of (1) the normal flow being to deserialize the
interface before deserializing its parameter and (2) a precise
ordering of work that was apparently recently disturbed,
perhaps by my abstract-serialization work or Bruno's ObjC
module merging work.

Fixes rdar://59153545.
2020-02-12 18:44:19 -05:00
Volodymyr Sapsai 83f4c3af02 [modules] Do not cache invalid state for modules that we attempted to load.
Partially reverts 0a2be46cfd as it turned
out to cause redundant module rebuilds in multi-process incremental builds.
When a module was getting out of date, all compilation processes started at the
same time were marking it as `ToBuild`. So each process was building the same
module instead of checking if it was built by someone else and using that
result. In addition to the work duplication, contention on the same .pcm file
wasn't making builds faster.

Note that for a single-process build this change would cause redundant module
reads and validations. But reading a module is faster than building it and
multi-process builds are more common than single-process. So I'm willing to
make such a trade-off.

rdar://problem/54395127

Reviewed By: dexonsmith

Differential Revision: https://reviews.llvm.org/D72860
2020-01-16 17:12:41 -08:00
Luboš Luňák cbc9d22e49 make -fmodules-codegen and -fmodules-debuginfo work also with PCHs
Allow to build PCH's (with -building-pch-with-obj and the extra .o file)
with -fmodules-codegen -fmodules-debuginfo to allow emitting shared code
into the extra .o file, similarly to how it works with modules. A bit of
a misnomer, but the underlying functionality is the same. This saves up
to 20% of build time here.

Differential Revision: https://reviews.llvm.org/D69778
2020-01-15 00:01:08 +01:00
Luboš Luňák b5b2cf7af4 fix recent -fmodules-codegen fix test 2020-01-14 23:51:07 +01:00
Tyker 9ec6d71211 [clang][modules] Add support for merging lifetime-extended temporaries
Summary: Add support for merging lifetime-extended temporaries

Reviewers: rsmith

Reviewed By: rsmith

Subscribers: xbolva00, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D70190
2019-12-02 19:55:13 +01:00
Tyker ae5484540f Revert "[clang][modules] Add support for merging lifetime-extended temporaries"
This reverts commit a3cbe1a202.
2019-12-01 22:38:31 +01:00
Tyker a3cbe1a202 [clang][modules] Add support for merging lifetime-extended temporaries
Summary: Add support for merging lifetime-extended temporaries

Reviewers: rsmith

Reviewed By: rsmith

Subscribers: xbolva00, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D70190
2019-12-01 21:28:48 +01:00
Tyker 486d1a5358 Revert "[clang][modules] Add support for merging lifetime-extended temporaries"
This reverts commit 85c7438477.
2019-12-01 11:58:14 +01:00
Tyker 85c7438477 [clang][modules] Add support for merging lifetime-extended temporaries
Summary: Add support for merging lifetime-extended temporaries

Reviewers: rsmith

Reviewed By: rsmith

Subscribers: xbolva00, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D70190
2019-11-30 23:09:11 +01:00
Tyker 3f4b70c79e Revert "[clang][modules] Add support for merging lifetime-extended temporaries"
This reverts commit 3c7f6b4396.
2019-11-30 17:52:26 +01:00
Tyker 3c7f6b4396 [clang][modules] Add support for merging lifetime-extended temporaries
Summary: Add support for merging lifetime-extended temporaries

Reviewers: rsmith

Reviewed By: rsmith

Subscribers: xbolva00, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D70190
2019-11-30 16:42:33 +01:00
Bruno Cardoso Lopes 3466cebe94 Add a test to cover structural match for recursive data types
This didn't use to work prior to r370639, now that this is supported
add a testcase to prevent regressions.

rdar://problem/53602368
2019-11-14 18:32:27 -08:00
Bruno Cardoso Lopes 919fc50034 [Modules][Objective-C] Use complete decl from module when diagnosing missing import
Summary:
Otherwise the definition (first found) for ObjCInterfaceDecl's might
precede the module one, which will eventually lead to crash, since
diagnoseMissingImport needs one coming from a module.

This behavior changed after Richard's r342018, which started to look
into the definition of ObjCInterfaceDecls.

rdar://problem/49237144

Reviewers: rsmith, arphaman

Subscribers: jkorous, dexonsmith, ributzka, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D66982

llvm-svn: 372039
2019-09-16 22:00:29 +00:00
Volodymyr Sapsai f91b6f8159 [Modules] Fix rebuilding an updated module for each of its consumers.
Marking a module for a rebuild when its signature differs from the
expected one causes redundant module rebuilds for incremental builds.
When a module is updated, its signature changes. But its consumers still
have the old signature and loading them will result in signature
mismatches. It will correctly cause the rebuilds for the consumers but
we don't need to rebuild the common module for each of them as it is
already up to date.

In practice this bug causes longer build times. We are doing more work
than required and only a single process can build a module, so parallel
builds degrade to a single-process mode where extra processes are just
waiting on a file lock.

Fix by not marking a module dependency for a rebuild on signature
mismatch. We'll check if it is up to date when we load it.

rdar://problem/50212358

Reviewers: dexonsmith, bruno, rsmith

Reviewed By: dexonsmith, bruno

Subscribers: jkorous, ributzka, cfe-commits, aprantl

Differential Revision: https://reviews.llvm.org/D66907

llvm-svn: 370274
2019-08-28 23:31:32 +00:00
David Blaikie aa3bf6ce72 Modules: Search for a visible definition of the decl context when computing visibility of a default template parameter
The code is/was already correct for the case where a parameter is a
parameter of its enclosing lexical DeclContext (functions and classes).
But for other templates (alias and variable templates) they don't create
their own scope to be members of - in those cases, they parameter should
be considered visible if any definition of the lexical decl context is
visible.

[this should cleanup the failure on the libstdc++ modules buildbot]
[this doesn't actually fix the variable template case for a
secondary/compounding reason (its lexical decl context is incorrectly
considered to be the translation unit)]

Test covers all 4 kinds of templates with default args, including a
regression test for the still broken variable template case.

Reviewers: rsmith

Differential Revision: https://reviews.llvm.org/D60892

llvm-svn: 358795
2019-04-19 23:02:30 +00:00
Duncan P. N. Exon Smith 0a2be46cfd Modules: Invalidate out-of-date PCMs as they're discovered
Leverage the InMemoryModuleCache to invalidate a module the first time
it fails to import (and to lock a module as soon as it's built or
imported successfully).  For implicit module builds, this optimizes
importing deep graphs where the leaf module is out-of-date; see example
near the end of the commit message.

Previously the cache finalized ("locked in") all modules imported so far
when starting a new module build.  This was sufficient to prevent
loading two versions of the same module, but was somewhat arbitrary and
hard to reason about.

Now the cache explicitly tracks module state, where each module must be
one of:

- Unknown: module not in the cache (yet).
- Tentative: module in the cache, but not yet fully imported.
- ToBuild: module found on disk could not be imported; need to build.
- Final: module in the cache has been successfully built or imported.

Preventing repeated failed imports avoids variation in builds based on
shifting filesystem state.  Now it's guaranteed that a module is loaded
from disk exactly once.  It now seems safe to remove
FileManager::invalidateCache, but I'm leaving that for a later commit.

The new, precise logic uncovered a pre-existing problem in the cache:
the map key is the module filename, and different contexts use different
filenames for the same PCM file.  (In particular, the test
Modules/relative-import-path.c does not build without this commit.
r223577 started using a relative path to describe a module's base
directory when importing it within another module.  As a result, the
module cache sees an absolute path when (a) building the module or
importing it at the top-level, and a relative path when (b) importing
the module underneath another one.)

The "obvious" fix is to resolve paths using FileManager::getVirtualFile
and change the map key for the cache to a FileEntry, but some contexts
(particularly related to ASTUnit) have a shorter lifetime for their
FileManager than the InMemoryModuleCache.  This is worth pursuing
further in a later commit; perhaps by tying together the FileManager and
InMemoryModuleCache lifetime, or moving the in-memory PCM storage into a
VFS layer.

For now, use the PCM's base directory as-written for constructing the
filename to check the ModuleCache.

Example
=======

To understand the build optimization, first consider the build of a
module graph TU -> A -> B -> C -> D with an empty cache:

    TU builds A'
       A' builds B'
          B' builds C'
             C' builds D'
                imports D'
          B' imports C'
             imports D'
       A' imports B'
          imports C'
          imports D'
    TU imports A'
       imports B'
       imports C'
       imports D'

If we build TU again, where A, B, C, and D are in the cache and D is
out-of-date, we would previously get this build:

    TU imports A
       imports B
       imports C
       imports D (out-of-date)
    TU builds A'
       A' imports B
          imports C
          imports D (out-of-date)
          builds B'
          B' imports C
             imports D (out-of-date)
             builds C'
             C' imports D (out-of-date)
                builds D'
                imports D'
          B' imports C'
             imports D'
       A' imports B'
          imports C'
          imports D'
     TU imports A'
        imports B'
        imports C'
        imports D'

After this commit, we'll immediateley invalidate A, B, C, and D when we
first observe that D is out-of-date, giving this build:

    TU imports A
       imports B
       imports C
       imports D (out-of-date)
    TU builds A' // The same graph as an empty cache.
       A' builds B'
          B' builds C'
             C' builds D'
                imports D'
          B' imports C'
             imports D'
       A' imports B'
          imports C'
          imports D'
    TU imports A'
       imports B'
       imports C'
       imports D'

The new build matches what we'd naively expect, pretty closely matching
the original build with the empty cache.

rdar://problem/48545366

llvm-svn: 355778
2019-03-09 17:44:01 +00:00
Duncan P. N. Exon Smith 9dda8f540c Modules: Add -Rmodule-import
Add a remark for importing modules.  Depending on whether this is a
direct import (into the TU being built by this compiler instance) or
transitive import (into an already-imported module), the diagnostic has
two forms:

    importing module 'Foo' from 'path/to/Foo.pcm'
    importing module 'Foo' into 'Bar' from 'path/to/Foo.pcm'

Also drop a redundant FileCheck invocation in Rmodule-build.m that was
using -Reverything, since the notes from -Rmodule-import were confusing
it.

https://reviews.llvm.org/D58891

llvm-svn: 355477
2019-03-06 02:50:46 +00:00
Alex Lorenz 7d76ef9b3d [HeaderSearch] loadSubdirectoryModuleMaps should respect -working-directory
Include search paths can be relative paths. The loadSubdirectoryModuleMaps function
should account for that and respect the -working-directory parameter given to Clang.

rdar://46045849

Differential Revision: https://reviews.llvm.org/D54503 

llvm-svn: 346822
2018-11-14 01:08:03 +00:00