Fix the indentation of the first line of preprocessor output

The -E output from clang did not produce the correct indentation on the first line.
This is because MoveToLine returned false, and when this happens,
the regular process for producing initial indentation is skipped.

Thanks to Eli for suggesting a way to simplify this to a one-line change.

llvm-svn: 173657

clang/lib/Frontend/PrintPreprocessedOutput.cpp

@@ -139,11 +139,15 @@ public:
                                 diag::Mapping Map, StringRef Str);
 
   bool HandleFirstTokOnLine(Token &Tok);
+
+  /// Move to the line of the provided source location. This will
+  /// return true if the output stream required adjustment or if
+  /// the requested location is on the first line.
   bool MoveToLine(SourceLocation Loc) {
     PresumedLoc PLoc = SM.getPresumedLoc(Loc);
     if (PLoc.isInvalid())
       return false;
-    return MoveToLine(PLoc.getLine());
+    return MoveToLine(PLoc.getLine()) || (PLoc.getLine() == 1);
   }
   bool MoveToLine(unsigned LineNo);
 

clang/test/Preprocessor/first-line-indent.c

@@ -0,0 +1,7 @@
+       foo
+// RUN: %clang_cc1 -E %s | FileCheck -strict-whitespace %s
+       bar
+
+// CHECK: {{^       }}foo
+// CHECK: {{^       }}bar
+