Extended Description

If you write a C file "foo.c" that says:
asm(".include "test-asm.s"");

And have an asm file named "/whatever/test-asm.s".

And if you run:
clang -I /whatever -c foo.c

Then, what should happen:
a) With integrated assembler, the search paths should be used by the integrated assembler to find the file.

b) Without an integrated assembler, the -I path arguments should be passed to the /usr/bin/as program, so it can handle the .include with the right paths. (note: gcc does indeed do this)

What happens now:

It fails to find the test-asm.s file, because search paths aren't passed into either assembler. It can the file (and does include it properly, even!), if the path is specified as relative to your current working directory.

Of course, writing C code like this is INCREDIBLY EVIL and nobody should ever do it. So I'm not planning to fix this. But, having discovered it, I thought I'd at least record a bug.

(Of course if you use this feature, -M can't work, because that stops after preprocessing, and this .include is not processed in the preprocessor. -MD could be made to work, IF you're using the integrated assembler, but that might be a bit of a confusing distinction?)