[Bug c/80832] New: GCC_COLORS

[Retyopiy at mail dot ru]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80832

            Bug ID: 80832
           Summary: GCC_COLORS
           Product: gcc
           Version: 5.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: Retyopiy at mail dot ru
  Target Milestone: ---

GCC_COLORS can contain "locus=" to colorize path to file, ":", line number,
":", column number and ":", but expected separate values:
- "file=" to colorize path to file (without ":");
- "line=" to colorize line number (without ":");
- "column=" to colorize column number (without ":");
- "colon=" to colorize ":".

GCC_COLORS can contain "error=", "warning=" and "note=" to colorize strings
"error:". "warning:" and "note:", but expected colorize strings without ":" and
use "colon=" to colorize ":".

Documentation page, like

https://gcc.gnu.org/onlinedocs/gcc-5.4.0/gcc/Language-Independent-Options.html

contain text "SGR substring for caret line", but term "caret line" is not
described. What is "caret line"?

Summary:
- implement "file=", "line=", "column=", "colon=";
- describe term "caret line".