Peek one token from an input stream

Determine if we have read everthing on the directive's line.

Skip to the end of the line (useful for recovering from errors in a directive)

UniformOrBuffer - 0: none; 1: uniform; 2: buffer

Peek the type of the next token, including macro expansion.

Find the currently-defined macro of the given name, or return NULL

Parse a body consisting of declarations

Get the location of the current (raw) token

in-place reversion, works only for ascii string

Destroy a macro

Create an input stream to represent a pre-tokenized input file. TODO(tfoley): pre-tokenizing files isn't going to work in the long run.

Determine whether the current preprocessor state means we should be skipping tokens.

Read one token with macro-expansion enabled. Note that because triggering macro expansion may involve changing the input-stream state, this operation