* Fix two issues with the SwiftGlibc module map.
The issues are:
- Today, some submodules in `SwiftGlibc` fail to provide definitions that
they should contain. As a consequence, Swift fails to import some code
that compiles correctly with standalone Clang. As just one example,
including `signal.h` should make the type `pid_t` available, but it
currently does not.
- `SwiftGlibc` is not compatible with the libc++ module map. Trying to
include libc++ headers in a C++ module imported into Swift results in an
error message about cyclic dependencies.
This change fixes both of these issues by making it so that `SwiftGlibc`
no actually longer defines a module map for the glibc headers but merely makes
all of the symbols from those headers available in a module that can be
imported into Swift. C / Objective-C / C++ code, on the other hand, will now
include the glibc headers texually.
For more context on the two issues and this fix, see this forum
discussion:
https://forums.swift.org/t/problems-with-swiftglibc-and-proposed-fix/37594
This change only modifies `glibc.modulemap.gyb` for the time being but
leaves `bionic.modulemap.gyb` and `libc-openbsd.modulemap.gyb` unchanged. The
intent is to fix these in the same way, but it will be easier to do this
in separate PRs that can be tested individually.
Co-authored-by: zoecarver <z.zoelec2@gmail.com>
Co-authored-by: Marcel Hlopko <hlopko@google.com>
Clang types need special treatment because multiple Clang modules can contain the same type declarations from a textually included header, but not all of these modules may be visible.
This fixes
https://bugs.swift.org/browse/SR-13032
The newly added test breaks without this fix.
Some of the patterns in the new test header are special-cased by
ClangImporter (for example, the names of typedefs become names of
imported structs).
Nested structs have been historically imported in Swift according to C
rules, that is, structs lexically declared nested in other structs are
imported into the global namespace anyway. For the same reason, C
structs have been mangled in Swift names as if they are declared in the
global namespace. These rules are problematic when importing C++, see
https://bugs.swift.org/browse/SR-12803.
