[PING] [PATCH] get source line for diagnostic from preprocessed file / PR preprocessor/79106

["Bader, Lucas" <lucas.bader@sap.com>]

Happy New Year and a ping for https://gcc.gnu.org/ml/gcc-patches/2019-12/msg01113.html 

-----Original Message-----
From: Bader, Lucas 
Sent: Montag, 16. Dezember 2019 12:19
To: gcc-patches@gcc.gnu.org
Subject: [PATCH] get source line for diagnostic from preprocessed file / PR preprocessor/79106

Hello,

within a compile cluster, only the preprocessed output of GCC is transferred to remote nodes for compilation. 
When GCC produces advanced diagnostics (with -fdiagnostics-show-caret), e.g. prints out the affected source
line and fixit hints, it attempts to read the source file again, even when compiling a preprocessed file (-fpreprocessed). 
This leads to wrong diagnostics when building with a compile cluster, or, more generally, when changing or deleting the original source file.

This patch attempts to alter the behavior by implementing a location_get_source_line_preprocessed 
function that can be used in diagnostic-show-locus.c in case a preprocessed file is compiled.
There was some previous discussion on this behavior on PR preprocessor/79106.

This is my first patch to GCC, so in case something is wrong with the format, please let me know.

Best regards
Lucas