Make a significant change to invert the control flow handling
predefined macros. Previously, these were handled by the driver,
now they are handled by the preprocessor.
Some fallout of this:
1. Instead of preprocessing two buffers (the predefines, then the
main source file) we now start preprocessing the main source
file and inject the predefines as a "psuedo #include" from the
main source file.
2. #1 allows us to nuke the Lexer::IsMainFile flag and simplify
Preprocessor::isInPrimaryFile.
3. The driver doesn't have to know about standard #defines, the
preprocessor knows, which is nice for people wanting to define
their own drivers.
4. This allows us to put normal tokens in the predefine buffer,
for example a definition for __builtin_va_list that is
target-specific, and a typedef for id in objc.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@42818 91177308-0d34-0410-b5e6-96231b3b80d8
8 files changed