[Bug preprocessor/55115] [4.9/5/6 Regression] missing headers as fatal breaks cproto logic

[Robert.Gomes at igt dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55115

--- Comment #18 from RGomes <Robert.Gomes at igt dot com> ---
The cproto design and usage is not broken. Everyone here agrees that a missing
include during "compilation" rightfully should generate an error. It is the
"preprocessor behavior only" where we are asking for tolerance for a missing
include. Why? Because a .h file that contains only function prototypes is being
generated ahead of the compilation (cproto is doing this step, using the gcc
preprocessor) - then later, that generated .h file "will" be present during
compilation. This is just one use case - there are others - so the request
being made is only for the preprocessor eliminating this error - not
compilation. (Followup to my earlier post - my present workaround was
reluctantly installing 2 gcc compilers: a 4.4 compatible one invoked for
prototyping only, and the latest gcc for compilation).