Make ASTContext explicitly keep track of the declaration for the C
FILE type, rather than using name lookup to find FILE within the
translation unit. Within precompiled headers, FILE is treated as yet
another "special type" (like __builtin_va_list).
This change should provide a performance improvement (not verified),
since the lookup into the translation unit declaration
forces the (otherwise unneeded) construction of a large hash table.
More importantly, with precompiled headers, the construction
of that table requires deserializing most of the top-level
declarations from the precompiled header, which are then unused.
Fixes PR 4509.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@74911 91177308-0d34-0410-b5e6-96231b3b80d8
7 files changed