[PATCH] D33424: Lexer: allow imaginary constants in GNU mode (only).

[Richard Smith via Phabricator via cfe-commits]

rsmith accepted this revision.
rsmith added a comment.
This revision is now accepted and ready to land.

I like it, and it seems like it would nicely generalize if there are more cases that we find need this treatment.



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Comment at: clang/lib/Lex/LiteralSupport.cpp:676-682
-      isLong = false;
-      isUnsigned = false;
-      isLongLong = false;
-      isFloat = false;
-      isHalf = false;
-      isImaginary = false;
-      MicrosoftInteger = 0;
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We should still do this if `s != ThisTokEnd`, rather than relying on `isValidUDSuffix` to also validate that we have a valid built-in suffix. (Eg, if C++20 adds an "in" suffix for "inches", this patch would treat "1.0in" as a valid `_Complex double` literal if no `operator""in` is found, because we don't validate that all the suffix characters are used on the fallback path.)


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Comment at: clang/lib/Lex/LiteralSupport.cpp:684
+    }
     return;
   }
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Redundant return. Remove? :)


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Comment at: clang/lib/Sema/SemaExpr.cpp:3355
+                                  /*DiagnoseMissing*/ !Literal.isImaginary)) {
+    case LOLR_Error: {
+      // Lookup failure for imaginary constants isn't fatal, there's still the
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I'd feel a bit more comfortable with a different return value for "lookup failed but we've not issued an error", to make it more obvious that we never return `ExprError()` here without issuing a diagnostic.


https://reviews.llvm.org/D33424