Sema: allow imaginary constants via GNU extension if UDL overloads not present.

C++14 added user-defined literal support for complex numbers so that you can
write something like "complex<double> val = 2i". However, there is an existing
GNU extension supporting this syntax and interpreting the result as a _Complex
type.

This changes parsing so that such literals are interpreted in terms of C++14's
operators if an overload is present but otherwise falls back to the original
GNU extension.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@303694 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 20 insertions, 25 deletions

diff --git a/lib/Lex/LiteralSupport.cpp b/lib/Lex/LiteralSupport.cpp
index fbfd3fe5cc..91993b1e41 100644
--- a/lib/Lex/LiteralSupport.cpp
+++ b/lib/Lex/LiteralSupport.cpp
@@ -652,9 +652,6 @@ NumericLiteralParser::NumericLiteralParser(StringRef TokSpelling,
           break;
         }
       }
-      // "i", "if", and "il" are user-defined suffixes in C++1y.
-      if (*s == 'i' && PP.getLangOpts().CPlusPlus14)
-        break;
       // fall through.
     case 'j':
     case 'J':
@@ -667,36 +664,34 @@ NumericLiteralParser::NumericLiteralParser(StringRef TokSpelling,
     break;
   }
 
-  if (s != ThisTokEnd) {
+  // "i", "if", and "il" are user-defined suffixes in C++1y.
+  if (s != ThisTokEnd || isImaginary) {
     // FIXME: Don't bother expanding UCNs if !tok.hasUCN().
     expandUCNs(UDSuffixBuf, StringRef(SuffixBegin, ThisTokEnd - SuffixBegin));
     if (isValidUDSuffix(PP.getLangOpts(), UDSuffixBuf)) {
-      // Any suffix pieces we might have parsed are actually part of the
-      // ud-suffix.
-      isLong = false;
-      isUnsigned = false;
-      isLongLong = false;
-      isFloat = false;
-      isHalf = false;
-      isImaginary = false;
-      MicrosoftInteger = 0;
+      if (!isImaginary) {
+        // Any suffix pieces we might have parsed are actually part of the
+        // ud-suffix.
+        isLong = false;
+        isUnsigned = false;
+        isLongLong = false;
+        isFloat = false;
+        isHalf = false;
+        isImaginary = false;
+        MicrosoftInteger = 0;
+      }
 
       saw_ud_suffix = true;
       return;
     }
 
-    // Report an error if there are any.
-    PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, SuffixBegin - ThisTokBegin),
-            diag::err_invalid_suffix_constant)
-      << StringRef(SuffixBegin, ThisTokEnd-SuffixBegin) << isFPConstant;
-    hadError = true;
-    return;
-  }
-
-  if (isImaginary) {
-    PP.Diag(PP.AdvanceToTokenCharacter(TokLoc,
-                                       ImaginarySuffixLoc - ThisTokBegin),
-            diag::ext_imaginary_constant);
+    if (s != ThisTokEnd) {
+      // Report an error if there are any.
+      PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, SuffixBegin - ThisTokBegin),
+              diag::err_invalid_suffix_constant)
+          << StringRef(SuffixBegin, ThisTokEnd - SuffixBegin) << isFPConstant;
+      hadError = true;
+    }
   }
 }