Re: No RSP_FILE if generating in a path that contains "@"
Some attempts, trying to decipher the Ninja generator code.
I believe the core problem is in IsIdentChar() that do not recognize '@' (as well as =,% and others?). The Ninja generator then uses EncodeIdent() to encode the filenames like
$identNN. This would be OK if not the command line length calculation calculated the length of without expansion, which happens to be below 8192 bytes on Windows(CMD limitation). The problem is therefore not related to ARMCC (other compilers worked, the command line were longer than 8192 still).
A response file should be used if the command is considered longer than the limit but operates on arguments after encoding (need to get the expanded size).