Controlled with a new flag '-direct-clang-cc1-module-build'
This will allow clients to formulate 'swift-frontend' invocations with fully-specified set of cc1 arguments (using '-Xcc -Xclang -Xcc <FLAG>') required for the PCM build, without having to go through the driver.
`e3c58386` introduced an ASAN error:
```
ERROR: AddressSanitizer: stack-use-after-scope on address ...
in swift::ClangImporter::Implementation::loadModuleClang ...
SUMMARY: AddressSanitizer: stack-use-after-scope ClangImporter.cpp:1903 in swift::ClangImporter::Implementation::loadModuleClang
```
rdar://99986478
C++ standard library module is called `std`. To make it more clear to a Swift developer that this module is a C++ stdlib, and not a Swift stdlib, let's rename it to `CxxStdlib`.
This is the first step in the module rename. We don't ban `std` in this patch to be able to build SwiftCompilerSources with hosttools until a new Swift compiler is shipped.
Basic should not be allowed to link Parse, yet it was doing so
to allow Version to provide a constructor that would conveniently
parse a StringRef. This entrypoint also emitted diagnostics, so it
pulled in libAST.
Sink the version parser entrypoint down into Parse where it belongs
and point all the clients to the right place.
Previously, when evaluating a `#if canImport(Module, _version: 42)` directive the compiler could diagnose and ignore the directive under the following conditions:
- The associated binary module is corrupt/bogus.
- The .tbd for an underlying Clang module is missing a current-version field.
This behavior is surprising when there is a valid `.swiftinterface` available and it only becomes apparent when building against an SDK with an old enough version of the module that the version in the `.swiftinterface` is too low, making this failure easy to miss. Some modules have different versioning systems for their Swift and Clang modules and it can also be intentional for a distributed binary `.swiftmodule` to contain bogus data (to force the compiler to recompile the `.swiftinterface`) so we need to handle both of these cases gracefully and predictably.
Now the compiler will enumerate all module loaders, ask each of them to attempt to parse the module version and then consistently use the parsed version from a single source. The `.swiftinterface` is preferred if present, then the binary module if present, and then finally the `.tbd`. The `.tbd` is still always used exclusively for the `_underlyingVersion` variant of `canImport()`.
Resolves rdar://88723492
Before this patch we tried to do lookup in the _ObjC module for the retain/release functions. Now we use the clang module that the reference type lives in.
The logic is here for this in the importer, which means the module interface tests make it appear that the behavior is correct, but lazy member lookup still finds the constructors, so this patch fixes that part.
This fixes an assertion that tripped when running `member-inline.swift` test with an unrelated patch:
```
type is not an l-value in LHS of assignment: Int32
...
3. While walking into body of setter for subscript(_:) (in module 'MemberInline')
```
Calling `NominalTypeDecl::lookupDirect` triggers deserialization of Swift extensions for the type. `ClangRecordMemberLookup` shouldn't assume it is allowed to deserialize Swift extensions for the given C++ type: there might be extensions which reference the module that is currently being imported, which causes circular request dependency errors.
This teaches ClangImporter to synthesize conformances of C++ iterator types to `UnsafeCxxInputIterator` protocol from the `Cxx` module.
We consider a C++ type to be an iterator if it defines a subtype (usually a typedef or a using decl) called `iterator_category` that inherits from `std::input_iterator_tag`.
rdar://96235368
This will fix modularization issues caused by the presence of Glibc and libstdc++ in a single context.
Some Glibc headers were getting hijacked by the libstdc++ module, and the decls in them were incorrectly determined to be a part of libstdc++. This caused compiler errors when trying to use those decls.
After this change, we will be able to reference Glibc headers directly from the module map, without using an additional header (`SwiftGlibc.h`).
This logic is going to be extended to inject the modulemap and the header of Glibc in addition to libstdc++. It doesn't depend on the rest of ClangImporter, so let's extract it to a separate file to make incremental builds and IDE features faster.
