2 files changed, 8 insertions, 2 deletions
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 8817469cbb..375c75c47e 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -222,6 +222,10 @@ static void DiagnosticOptsToArgs(const DiagnosticOptions &Opts,
     Res.push_back("-verify");
   if (Opts.ShowOptionNames)
     Res.push_back("-fdiagnostics-show-option");
+  if (Opts.TabStop != 8) {
+    Res.push_back("-ftabstop");
+    Res.push_back(llvm::utostr(Opts.TabStop));
+  }
   if (Opts.MessageLength) {
     Res.push_back("-fmessage-length");
     Res.push_back(llvm::utostr(Opts.MessageLength));
@@ -804,6 +808,7 @@ static void ParseDiagnosticArgs(DiagnosticOptions &Opts, ArgList &Args,
   Opts.ShowOptionNames = Args.hasArg(OPT_fdiagnostics_show_option);
   Opts.ShowSourceRanges = Args.hasArg(OPT_fdiagnostics_print_source_range_info);
   Opts.VerifyDiagnostics = Args.hasArg(OPT_verify);
+  Opts.TabStop = getLastArgIntValue(Args, OPT_ftabstop, 8, Diags);
   Opts.MessageLength = getLastArgIntValue(Args, OPT_fmessage_length, 0, Diags);
   Opts.DumpBuildInformation = getLastArgValue(Args, OPT_dump_build_information);
   Opts.Warnings = getAllArgValues(Args, OPT_W);
diff --git a/lib/Frontend/TextDiagnosticPrinter.cpp b/lib/Frontend/TextDiagnosticPrinter.cpp
index 61f8a70fff..c27d112c03 100644
--- a/lib/Frontend/TextDiagnosticPrinter.cpp
+++ b/lib/Frontend/TextDiagnosticPrinter.cpp
@@ -378,9 +378,10 @@ void TextDiagnosticPrinter::EmitCaretDiagnostic(SourceLocation Loc,
     // Replace this tab with at least one space.
     SourceLine[i] = ' ';
 
+    unsigned TabStop = DiagOpts->TabStop > 0 ? DiagOpts->TabStop : 8;
     // Compute the number of spaces we need to insert.
-    unsigned NumSpaces = ((i+8)&~7) - (i+1);
-    assert(NumSpaces < 8 && "Invalid computation of space amt");
+    unsigned NumSpaces = ((i+TabStop)/TabStop * TabStop) - (i+1);
+    assert(NumSpaces < TabStop && "Invalid computation of space amt");
 
     // Insert spaces into the SourceLine.
     SourceLine.insert(i+1, NumSpaces, ' ');