Translation implementation (Using the GNU Compiler Collection (GCC))

4.1 Translation

How a diagnostic is identified (C90 3.7, C99 and C11 3.10, C90, C99 and C11 5.1.1.3).

Diagnostics consist of all the output sent to stderr by GCC.

Whether each nonempty sequence of white-space characters other than new-line is retained or replaced by one space character in translation phase 3 (C90, C99 and C11 5.1.1.2).
See Implementation-defined behavior in The C Preprocessor.