More use cases

[mathstuf]

Some other use cases to add to this repository that I've mentioned elsewhere (Slack or Reddit):

• generated sources
• code that can confuse naïve scanners:

const char* foo = "
#include <vector>
import M;
";

• module names expanded from macros (import and export)
• module names expanded from macros on the command line (import and export)
• overlapping file basenames (foo.mpp and foo.cpp)

[RedBeard0531]

I think to be conforming, that example would need to use a `R"(raw string)" since it spans multiple lines. I'd also make it use names that don't exist so it can't accidentally work.

Also missing is a test of importing a module from inside a non-translated #included header.

[RedBeard0531]

Should have a test with attributes like import foo [[ns::a]] [[ns::b]];. Could be really evil and do import foo [[ns::evil("]]")]]; to break regexes that try to match attributes like import\s+((\w+)(\s*\.\s*\w+)*) *(\[\[[^\]]*\]\] *)*; .

[RedBeard0531]

#define NO_SUCH_MODULE <some_header.h>
import NO_SUCH_MODULE;

Should be handled as a header unit import of <some_header.h> rather than importing a module named NO_SUCH_MODULE.

[mathstuf]

We also have the line continuation splits after @boris-kolpackov's paper. A few existing examples may now be ill-formed after that as well.