[c++2a] P0515R3: lexer support for new <=> token.

llvm-svn: 319509

2 files changed, 24 insertions, 0 deletions

diff --git a/clang/lib/Lex/Lexer.cpp b/clang/lib/Lex/Lexer.cpp
index 67dcff6b715..b06971968fc 100644
--- a/clang/lib/Lex/Lexer.cpp
+++ b/clang/lib/Lex/Lexer.cpp
@@ -3522,6 +3522,24 @@ LexNextToken:
         Kind = tok::lessless;
       }
     } else if (Char == '=') {
+      char After = getCharAndSize(CurPtr+SizeTmp, SizeTmp2);
+      if (After == '>') {
+        if (getLangOpts().CPlusPlus2a) {
+          if (!isLexingRawMode())
+            Diag(BufferPtr, diag::warn_cxx17_compat_spaceship);
+          CurPtr = ConsumeChar(ConsumeChar(CurPtr, SizeTmp, Result),
+                               SizeTmp2, Result);
+          Kind = tok::spaceship;
+          break;
+        }
+        // Suggest adding a space between the '<=' and the '>' to avoid a
+        // change in semantics if this turns up in C++ <=17 mode.
+        if (getLangOpts().CPlusPlus && !isLexingRawMode()) {
+          Diag(BufferPtr, diag::warn_cxx2a_compat_spaceship)
+            << FixItHint::CreateInsertion(
+                   getSourceLocation(CurPtr + SizeTmp, SizeTmp2), " ");
+        }
+      }
       CurPtr = ConsumeChar(CurPtr, SizeTmp, Result);
       Kind = tok::lessequal;
     } else if (LangOpts.Digraphs && Char == ':') {     // '<:' -> '['
diff --git a/clang/lib/Lex/TokenConcatenation.cpp b/clang/lib/Lex/TokenConcatenation.cpp
index d1facd9c687..c1ee28dcc18 100644
--- a/clang/lib/Lex/TokenConcatenation.cpp
+++ b/clang/lib/Lex/TokenConcatenation.cpp
@@ -103,6 +103,10 @@ TokenConcatenation::TokenConcatenation(Preprocessor &pp) : PP(pp) {
   if (PP.getLangOpts().CPlusPlus1z)
     TokenInfo[tok::utf8_char_constant] |= aci_custom;
 
+  // These tokens have custom code in C++2a mode.
+  if (PP.getLangOpts().CPlusPlus2a)
+    TokenInfo[tok::lessequal ] |= aci_custom_firstchar;
+
   // These tokens change behavior if followed by an '='.
   TokenInfo[tok::amp         ] |= aci_avoid_equal;           // &=
   TokenInfo[tok::plus        ] |= aci_avoid_equal;           // +=
@@ -283,5 +287,7 @@ bool TokenConcatenation::AvoidConcat(const Token &PrevPrevTok,
     return FirstChar == '#' || FirstChar == '@' || FirstChar == '%';
   case tok::arrow:           // ->*
     return PP.getLangOpts().CPlusPlus && FirstChar == '*';
+  case tok::lessequal:       // <=> (C++2a)
+    return PP.getLangOpts().CPlusPlus2a && FirstChar == '>';
   }
 }