Header name contains a character with undefined behavior

Reports an #include or #import whose header name contains an apostrophe, a backslash, a double quote, // or an embedded /*. A single / used as a directory separator is not reported.

Inside a header name these characters have undefined behavior; the standard leaves each toolchain free to interpret them as it likes. A backslash is the usual offender, carried over from a Windows path, and toolchains disagree on whether it separates directories or starts an escape sequence, so the same source resolves to a different file - or to no file - on a different compiler. // and /* additionally risk being read as the start of a comment.

The following code illustrates the pattern detected by this rule:

Write the header name with forward slashes and no quoting characters, for example #import <XYCore/XYSession.h>. Rename any header whose file name itself contains one of these characters.

This detector does not need any configuration.