Index: clang/lib/Format/Format.cpp
===================================================================
--- clang/lib/Format/Format.cpp
+++ clang/lib/Format/Format.cpp
@@ -2032,6 +2032,10 @@
     };
 
     for (auto Line : AnnotatedLines) {
+      if (Line->First && (Line->First->TokenText.startswith("#") ||
+                          Line->First->TokenText == "__pragma" ||
+                          Line->First->TokenText == "_Pragma"))
+        continue;
       for (const FormatToken *FormatTok = Line->First; FormatTok;
            FormatTok = FormatTok->Next) {
         if ((FormatTok->Previous && FormatTok->Previous->is(tok::at) &&
Index: clang/unittests/Format/FormatTest.cpp
===================================================================
--- clang/unittests/Format/FormatTest.cpp
+++ clang/unittests/Format/FormatTest.cpp
@@ -16713,6 +16713,15 @@
       guessLanguage("foo.h", "int(^foo[(kNumEntries + 10)])(char, float);"));
 }
 
+TEST_F(FormatTest, GuessLanguageWithPragmas) {
+  EXPECT_EQ(FormatStyle::LK_Cpp,
+            guessLanguage("foo.h", "__pragma(warning(disable:))"));
+  EXPECT_EQ(FormatStyle::LK_Cpp,
+            guessLanguage("foo.h", "#pragma(warning(disable:))"));
+  EXPECT_EQ(FormatStyle::LK_Cpp,
+            guessLanguage("foo.h", "_Pragma(warning(disable:))"));
+}
+
 TEST_F(FormatTest, FormatsInlineAsmSymbolicNames) {
   // ASM symbolic names are identifiers that must be surrounded by [] without
   // space in between: