[Bug preprocessor/55115] [>=4.5.0 regression] missing headers as fatal breaks cproto logic

[pierre.poissinger at gmail dot com]

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

--- Comment #11 from Pierre Poissinger <pierre.poissinger at gmail dot com> 2012-10-31 22:46:07 UTC ---
Created attachment 28588
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=28588
Don't treat missing headers as fatal error if only preproc

Following patch allows preproc only (-E) to not treat missing headers as a
fatal error - a non-fatal error will be raised, as pre-4.5, for that specific
case.

In addition:
* Updated 2 cpp testcases (include2.c/include2a.c) to use "compile" instead of
preproc, so 'terminated' test can be checked
* Added a new cpp testcase (include2b.c) to check preproc will return 'missing
header' error, but does not stop preproc

Notes:
- Patch is done on gcc-4_7-branch
- Did not spot any difference with check-gcc before/after patch [expect
additional testcase]
- Seems to fix my cproto issues