[PATCH] D20959: [clang-format] make header guard identification stricter (with Lexer).

[Eric Liu via cfe-commits]

ioeric added inline comments.

================
Comment at: lib/Format/Format.cpp:1500
@@ +1499,3 @@
+  // Get the first token.
+  Lex.LexFromRawLexer(Tok);
+  skipComments(Lex, Tok);
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djasper wrote:
> Can this go wrong? Maybe in an empty file?
Added a test case for empty file.

If the code is empty, Tok will be `tok::eof`, which would leave `MinInsertionOffset` as `Code.size()`. 

But the program does fail when we insert at the end of code that does not end with '\n'. We always +1 when we calculate the offset for each line (in the for-loop on Lines); however, the last line does not necessarily end with '\n', which makes offset exceed code size. I will fix this in a follow-up patch.



http://reviews.llvm.org/D20959