#3159 warning: missing terminating ' character from preprocessor

[Philipp Klaus Krause]

E.g. for the following code

int i = 1'000;

We get a "warning: missing terminating ' character" from the preprocessor. Apparently this always happens when the number of ' in a line is odd. Apparently the preprocessor lexer in libcpp/lex.c tries to lex part of the number as a character literal.

The fix would probably be to implement handling of digit separators in preprocessor number lexing. I don't know if that is worth it, though. Maybe we instead want to go for a new preprocessor (e.g. one derived from current GCC or LLVM) that already supports digit separators (and other newer C features).

[Philipp Klaus Krause]

The preprocessor in GCC 12.1 has support for digit separators, so by rebasing our fork on that one, this issues can be fixed.

[Felix]

The preprocessor has been updated to cpp from gcc 12.1.0. [r13690], fixing this issue as suggested.