[Bug preprocessor/60723] Line directives with incorrect system header flag

[sje at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60723

Steve Ellcey <sje at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |sje at gcc dot gnu.org

--- Comment #29 from Steve Ellcey <sje at gcc dot gnu.org> ---
I posted this question on gcc@gcc.gnu.org and got not response so I thought I
would ask here on the bug report.

I am trying to understand the status of this bug and the patch
that fixes it.  It looks like a patch was submitted and checked
in for 5.0 to fix the problem reported and I see the new 
behavior caused by the patch in GCC 5.X compilers.  This behavior
caused a number of issues with configures and scripts that examined
preprocessed output as is mentioned in this bug report.
There was a later bug, 64864, complaining about the behavior and
that was closed as invalid.

But when I look at GCC 6.X or ToT (7.X) compilers I do not see the same
behavior as 5.X.  Was this patch reverted or was a new patch submitted
that undid some of this patches behavior?  I couldn't find any revert or
new patch to replace the original one so I am not sure when or why
the code changed back after the 5.X releases.

Here is a test case that I am preprocessing with g++ -E:

#include <stdbool.h>
class foo {
        void operator= ( bool bit);
        operator bool() const;
};

GCC 5.4 breaks up the operator delcarations with line markers and GCC 6.2
does not.