This test started failing on Windows after b45888e9 due to path separators not matching up.

Since D106876, PCM files don't report module maps as input files unless they contributed to the compilation.

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

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

Depends on D120463.

Reviewed By: dexonsmith

Differential Revision: https://reviews.llvm.org/D120464

This patch simplifies a test that checks only used module map files are reported as input files in PCM files.

Instead of using opaque `diff`, this patch uses `clang -module-file-info` and `FileCheck` to verify this.

Reviewed By: dexonsmith

Differential Revision: https://reviews.llvm.org/D120463

Implementation partitions bring two extra cases where we have
visibility of module-private data.

1) When we import a module implementation partition.
2) When a partition implementation imports the primary module intertace.

We maintain a record of direct imports into the current module since
partition decls from direct imports (but not trasitive ones) are visible.

The rules on decl-reachability are much more relaxed (with the standard
giving permission for an implementation to load dependent modules and for
the decls there to be reachable, but not visible).

Differential Revision: https://reviews.llvm.org/D118599

We cannot export partition implementation CMIs, but we can export the content
of partition interface CMIs.

Differential Revision: https://reviews.llvm.org/D118588

Partition implementations are special, they generate a CMI, but it
does not have an 'export' line, and we cannot export anything from the
it [that is it can only make decls available to other members of the
owning module, not to importers of that].

Add initial testcases for partition handling, derived from the examples in
Section 10 of the C++20 standard, which identifies what should be accepted
and/or rejected.

Differential Revision: https://reviews.llvm.org/D118587

This patch adds -Wno-strict-prototypes to all of the test cases that
use functions without prototypes, but not as the primary concern of the
test. e.g., attributes testing whether they can/cannot be applied to a
function without a prototype, etc.

This is done in preparation for enabling -Wstrict-prototypes by
default.

This implements the parsing and recognition of module partition CMIs
and removes the FIXMEs in the parser.

Module partitions are recognised in the base computation of visibility,
however additional amendments to visibility follow in subsequent patches.

Differential Revision: https://reviews.llvm.org/D118586

This patch enables inferring framework modules in explicit builds in all contexts. Until now, inferring framework modules only worked with `-fimplicit-module-maps` due to this block of code:

```
// HeaderSearch::loadFrameworkModule
  case LMM_InvalidModuleMap:
    // Try to infer a module map from the framework directory.
    if (HSOpts->ImplicitModuleMaps)
      ModMap.inferFrameworkModule(Dir, IsSystem, /*Parent=*/nullptr);
    break;
```

Reviewed By: Bigcheese

Differential Revision: https://reviews.llvm.org/D113880

This switches the testcase committed for initial C++20 modules import tracking to
use split-file rather than preprocessor directives.

Differential Revision: https://reviews.llvm.org/D120352

It is useful to be able to visualise the C++20 modules content of a PCM file
both for inspection and for testing.  In particular, when adding more module
types to support C++20 Partitions and Header Units, we would like to be able
to confirm that the output PCM has the intended structure.

The existing scheme for dumping data is restricted to the content of the AST
file control block, which does not include structural data beyond imports.

The change here makes use of the AST unit that is set up by BeginSourceFile
to query for the information on the primary and sub-modules.  We can then
inspect each of these in turn, accounting for Global, Private, Imported and
Exported modules/fragments and then showing the sub-stucture of the main
module(s).

The disadvantage of this mechanism is that it has no easy method to control
the granularity of the output.  Perhaps more detailed inspection would be
better handled by a stand-alone module inspection tool.

Differential Revision: https://reviews.llvm.org/D119823

In C++20 modules imports must be together and at the start of the module.
Rather than growing more ad-hoc flags to test state, this keeps track of the
phase of of a valid module TU (first decl, global module frag, module,
private module frag).  If the phasing is broken (with some diagnostic) the
pattern does not conform to a valid C++20 module, and we set the state
accordingly.

We can thus issue diagnostics when imports appear in the wrong places and
decouple the C++20 modules state from other module variants (modules-ts and
clang modules).  Additionally, we attempt to diagnose wrong imports before
trying to find the module where possible (the latter will generally emit an
unhelpful diagnostic about the module not being available).

Although this generally simplifies the handling of C++20 module import
diagnostics, the motivation was that, in particular, it allows detecting
invalid imports like:

import module A;

int some_decl();

import module B;

where being in a module purview is insufficient to identify them.

Differential Revision: https://reviews.llvm.org/D118893

This reverts commit 8a3f9a58.

need to investigate build failures that do not show on CI or local
testing.

In C++20 modules imports must be together and at the start of the module.
Rather than growing more ad-hoc flags to test state, this keeps track of the
phase of of a valid module TU (first decl, global module frag, module,
private module frag).  If the phasing is broken (with some diagnostic) the
pattern does not conform to a valid C++20 module, and we set the state
accordingly.

We can thus issue diagnostics when imports appear in the wrong places and
decouple the C++20 modules state from other module variants (modules-ts and
clang modules).  Additionally, we attempt to diagnose wrong imports before
trying to find the module where possible (the latter will generally emit an
unhelpful diagnostic about the module not being available).

Although this generally simplifies the handling of C++20 module import
diagnostics, the motivation was that, in particular, it allows detecting
invalid imports like:

import module A;

int some_decl();

import module B;

where being in a module purview is insufficient to identify them.

Differential Revision: https://reviews.llvm.org/D118893

An impilt used of C++ module without prebuild path may cause crash.

For example:

```
// ./dir1/C.cppm
export module C;
// ./dir2/B.cppm
export module B;
import C;
// ./A.cpp
import B;
import C;
```

When we compile A.cpp without the prebuild path of C.pcm, the compiler
will crash.

```
clang++ -std=c++20 --precompile -c ./dir1/C.cppm -o ./dir1/C.pcm
clang++ -std=c++20 --precompile -fprebuilt-module-path=./dir2  -c
./dir2/B.cppm -o ./dir2/B.pcm
clang++ -std=c++20 -fprebuilt-module-path=./dir2 A.cpp

```

The prebuilt path of module C is cached when import module B, and in the
function HeaderSearch::getCachedModuleFileName, the compiler try to get
the filename by modulemap without check if modulemap exists, and there
is no modulemap in C++ module.

Reviewed By: ChuanqiXu

Differential review: https://reviews.llvm.org/D119426

A significant number of our tests in C accidentally use functions
without prototypes. This patch converts the function signatures to have
a prototype for the situations where the test is not specific to K&R C
declarations. e.g.,

  void func();

becomes

  void func(void);

This is the seventh batch of tests being updated (there are a
significant number of other tests left to be updated).

The test case otherwise fails an assertion in Diagnostic::getArgKind().

Differential Revision: https://reviews.llvm.org/D116595

This patch emits an error on AIX and z/OS because XCOFF and GOFF does not currently implement builtin function `CFStringMakeConstantString`. Tests that use this builtin were also disabled.

Reviewed By: SeanP

Differential Revision: https://reviews.llvm.org/D117315

Turning on `enable_noundef_analysis` flag allows better codegen by removing freeze instructions.
I modified clang by renaming `enable_noundef_analysis` flag to `disable-noundef-analysis` and turning it off by default.

Test updates are made as a separate patch: D108453

Reviewed By: eugenis

Differential Revision: https://reviews.llvm.org/D105169

This patch fixes a crash due to following simple program:
> export struct Unit {
>    bool operator<(const Unit&);
> };

It would crash since the compiler would set the module ownership for
Unit. And the declaration with a module ownership is assumed to own a
module. But here isn't one. So here is the crash.

This patch fixes this by exiting early if it finds the export decl is
already invalid.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D117093

As suggested in:
https://reviews.llvm.org/D114895#3177794
X will be converted to i by SelectionDAGISEL anyways.

Reviewed By: void, jyknight

Differential Revision: https://reviews.llvm.org/D115311

The compiler would crash if we lookup for name in transparent decl
context. See the tests attached for example.

I think this should make sense since the member declared in transparent
DeclContext are semantically defined in the enclosing (non-transparent)
DeclContext, this is the definition for transparent DeclContext.

Reviewed By: erichkeane

Differential Revision: https://reviews.llvm.org/D116792

Because of commit: https://reviews.llvm.org/D104291 the -gmodules .pcm
files do not have the same DW_AT_language dialect as the .o file. This
was a simple matter of passing the DebugStrictDwarf flag to the
PCHContainerGenerator object's CodeGenOpts from the CompilerInstance
passed in to it.

Before this change if you ran dwarfdump on the gmodule cache folder
you would get DW_AT_language (DW_LANG_C_plus_plus) even when using
-std=c++14 with clang

Patch by Shubham Rastogi!

Differential Revision: https://reviews.llvm.org/D116790

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

In C++20 Modules, imported module which doesn't get exported wouldn't be
recorded. This patch would record such modules to avoid possible
incorrect visibility problems.

Reviewed By: urnathan

Differential Revision: https://reviews.llvm.org/D116098

This reverts commit 368318bc.

The title is not right. It should be a patch about modules instead of
coroutines.

In C++20 Modules, imported module which doesn't get exported wouldn't be
recorded. This patch would record such modules to avoid possible
incorrect visibility problems.

Reviewed By: urnathan

Differential Revision: https://reviews.llvm.org/D116098

This commit adds two test about template class instantiation in
transitively imported module. They are used as pre-commit tests for
successive patches.

Differential Revision: https://reviews.llvm.org/D116097

Revert "[NFC] [C++20] [Modules] Add tests for template instantiation in transitively imported module"

This reverts commit 4f103e95.

The tests couldn't pass under windows.

This commit adds two test about template class instantiation in
transitively imported module. They are used as pre-commit tests for
successive patches.

Implement `getUnresolvedUsingType()` and don't create a new
`UnresolvedUsingType` when there is already canonical declaration.

This solved an incorrect ODR detection in modules for uresolved using
type.

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D115792

The compiler would judge two concepts is same by their addresses.
However, when we use modules, the addresses wouldn't be the same all the
time since one is parsed in their TU and another is imported in another
TU.
This patch fixes this by using isSameEntity to judge the two concepts.

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D114769

Part of work to use more inclusive terms in clang/llvm.

Problem:
PCM file includes references to all module maps used in compilation which created PCM. This problem leads to PCM-rebuilds in distributed compilations as some module maps could be missing in isolated compilation. (For example in our distributed build system we create a temp folder for every compilation with only modules and headers that are needed for that particular command).

Solution:
Add only affecting module map files to a PCM-file.

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D106876

Reviewed By: jsji

Differential Revision: https://reviews.llvm.org/D113654

Merge definition visibility the same way we do for other decls. Without
the fix the added test emits `-Wobjc-method-access` as it cannot find a
visible protocol. Make this warning `-Werror` so the test would fail
when protocol visibility regresses.

rdar://83600696

Differential Revision: https://reviews.llvm.org/D111860

Revert "[Clang/Test]: Rename enable_noundef_analysis to disable-noundef-analysis and turn it off by default"

This reverts commit aacfbb95.

Revert "Fix lit test failures in CodeGenCoroutines"

This reverts commit 63fff0f5.