https://issues.dlang.org/show_bug.cgi?id=22591

          Issue ID: 22591
           Summary: importC: Debug information for C sources have
                    DW_AT_language set to D.
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: normal
          Priority: P1
         Component: dmd
          Assignee: nobody@puremagic.com
          Reporter: ibuclaw@gdcproject.org

Not a big issue, but C sources should have their language set to C so gdb knows better how to interpret the generated debug information.

--