This patch changes type of the `File` parameter in `PPCallbacks::InclusionDirective()` from `const FileEntry *` to `Optional<FileEntryRef>`.
With the API change in place, this patch then removes some uses of the deprecated `FileEntry::getName()` (e.g. in `DependencyGraph.cpp` and `ModuleDependencyCollector.cpp`).
Reviewed By: dexonsmith, bnbarham
Differential Revision: https://reviews.llvm.org/D123574
enum FileChangeReason has four possible type EnterFile, ExitFile,
SystemHeaderPragma and RenameFile,
It should pop the back element of Files only if FileChangeReason is ExitFile.
Looks for duplicate includes and removes them.
Every time an include directive is processed, check a vector of filenames
to see if the included file has already been included. If so, it issues
a warning and a replacement to remove the entire line containing the
duplicated include directive.
When a macro is defined or undefined, the vector of filenames is cleared.
This enables including the same file multiple times, but getting
different expansions based on the set of active macros at the time of
inclusion. For example:
#undef NDEBUG
#include "assertion.h"
// ...code with assertions enabled
#define NDEBUG
#include "assertion.h"
// ...code with assertions disabled
Since macros are redefined between the inclusion of assertion.h,
they are not flagged as redundant.
Differential Revision: https://reviews.llvm.org/D7982
Kazu Hirata