[PATCH] D150843: [clang][Diagnostics] Refactor printableTextForNextCharacter

[Corentin Jabot via Phabricator via cfe-commits]

cor3ntin added a comment.

This generally looks good to me but i have a couple remarks



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Comment at: clang/lib/Frontend/TextDiagnostic.cpp:124-128
+  if (CharSize == 1 && llvm::isLegalUTF8Sequence(Begin, End) &&
+      llvm::sys::locale::isPrint(*Begin)) {
+    ++(*I);
+    return std::make_pair(SmallString<16>(Begin, End), true);
+  }
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this could be simplified : the common case for ascii could be just looking at `isPrint(*Begin);` (which implies  CharSize == 1 and  llvm::isLegalUTF8Sequence(Begin, End))
So you could do it before computing CharSize


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Comment at: clang/lib/Frontend/TextDiagnostic.cpp:132
+  // Convert it to UTF32 and check if it's printable.
+  if (llvm::isLegalUTF8Sequence(Begin, End)) {
+    llvm::UTF32 C;
----------------
I think we should check that `CharSize` is not greater than `Begin + SourceLine.size() - *i`  or something along those lines otherwise we may overflow SourceLine.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D150843/new/

https://reviews.llvm.org/D150843