[Driver] Don't add -dwarf-column-info when using -gcodeview on non-msvc targets

[mstorsjo]

Summary

-dwarf-column-info is omitted if -gcodeview is specified for msvc targets at the moment, but since -gcodeview is an option that can be specified for any target, there's little reason to restrict this handling to msvc targets.

This allows getting proper codeview debug info by passing -gcodeview for e.g. MinGW targets as well.

[smeenai]

Makes sense to me. You may wanna wait for @zturner, but I can't really imagine any benefit to restricting this to MSVC.

lib/Driver/ToolChains/Clang.cpp

   Args.ClaimAllArgs(options::OPT_g_flags_Group);
 
   // Column info is included by default for everything except SCE and CodeView.
   // Clang doesn't track end columns, just starting columns, which, in theory,
   // is fine for CodeView (and PDB).  In practice, however, the Microsoft
   // debuggers don't handle missing end columns well, so it's better not to
   // include any column info.
   if (Args.hasFlag(options::OPT_gcolumn_info, options::OPT_gno_column_info,
-                   /*Default=*/!(IsWindowsMSVC && EmitCodeView) &&
+                   /*Default=*/!EmitCodeView &&
                        DebuggerTuning != llvm::DebuggerKind::SCE))
     CmdArgs.push_back("-dwarf-column-info");
 
   // FIXME: Move backend command line options to the module.
   // If -gline-tables-only is the last option it wins.
   if (DebugInfoKind != codegenoptions::DebugLineTablesOnly &&
       Args.hasArg(options::OPT_gmodules)) {
     DebugInfoKind = codegenoptions::LimitedDebugInfo;

test/Driver/codeview-column-info.c

 // Check that -dwarf-column-info does not get added to the cc1 line:
 // 1) When -gcodeview is present via the clang or clang++ driver
 // 2) When /Z7 is present via the cl driver.
 
 // RUN: %clang -### --target=x86_64-windows-msvc -c -g -gcodeview %s 2> %t1
 // RUN: FileCheck < %t1 %s
 // RUN: %clangxx -### --target=x86_64-windows-msvc -c -g -gcodeview %s 2> %t2
 // RUN: FileCheck < %t2 %s
+// RUN: %clangxx -### --target=x86_64-windows-gnu -c -g -gcodeview %s 2> %t2
+// RUN: FileCheck < %t2 %s
 // RUN: %clang_cl -### --target=x86_64-windows-msvc /c /Z7 -- %s 2> %t2
 // RUN: FileCheck < %t2 %s
 
 // CHECK: "-cc1"
 // CHECK-NOT: "-dwarf-column-info"