2 files changed, 20 insertions, 0 deletions
diff --git a/clang/lib/Analysis/PrintfFormatString.cpp b/clang/lib/Analysis/PrintfFormatString.cpp
index d99de2215dc..82ab14dbed6 100644
--- a/clang/lib/Analysis/PrintfFormatString.cpp
+++ b/clang/lib/Analysis/PrintfFormatString.cpp
@@ -590,6 +590,24 @@ bool PrintfSpecifier::hasValidLeftJustified() const {
   }
 }
 
+bool PrintfSpecifier::hasValidThousandsGroupingPrefix() const {
+  if (!HasThousandsGrouping)
+    return true;
+  
+  switch (CS.getKind()) {
+    case ConversionSpecifier::dArg:
+    case ConversionSpecifier::iArg:
+    case ConversionSpecifier::uArg:
+    case ConversionSpecifier::fArg:
+    case ConversionSpecifier::FArg:
+    case ConversionSpecifier::gArg:
+    case ConversionSpecifier::GArg:
+      return true;
+    default:
+      return false;
+  }
+}
+
 bool PrintfSpecifier::hasValidPrecision() const {
   if (Precision.getHowSpecified() == OptionalAmount::NotSpecified)
     return true;
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index 75b30fcb769..0ca1ce52ab1 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -1491,6 +1491,8 @@ CheckPrintfHandler::HandlePrintfSpecifier(const analyze_printf::PrintfSpecifier
   }
 
   // Check each flag does not conflict with any other component.
+  if (!FS.hasValidThousandsGroupingPrefix())
+    HandleFlag(FS, FS.hasThousandsGrouping(), startSpecifier, specifierLen);
   if (!FS.hasValidLeadingZeros())
     HandleFlag(FS, FS.hasLeadingZeros(), startSpecifier, specifierLen);
   if (!FS.hasValidPlusPrefix())