Add a new expression node, CXXOperatorCallExpr, which expresses a

function call created in response to the use of operator syntax that
resolves to an overloaded operator in C++, e.g., "str1 +
str2" that resolves to std::operator+(str1, str2)". We now build a
CXXOperatorCallExpr in C++ when we pick an overloaded operator. (But
only for binary operators, where we actually implement overloading)

I decided *not* to refactor the current CallExpr to make it abstract
(with FunctionCallExpr and CXXOperatorCallExpr as derived
classes). Doing so would allow us to make CXXOperatorCallExpr a little
bit smaller, at the cost of making the argument and callee accessors
virtual. We won't know if this is going to be a win until we can parse
lots of C++ code to determine how much memory we'll save by making
this change vs. the performance penalty due to the extra virtual
calls.

llvm-svn: 59306

1 files changed, 12 insertions, 1 deletions

diff --git a/clang/lib/Basic/IdentifierTable.cpp b/clang/lib/Basic/IdentifierTable.cpp
index b8684753b2c..4d737c50bc0 100644
--- a/clang/lib/Basic/IdentifierTable.cpp
+++ b/clang/lib/Basic/IdentifierTable.cpp
@@ -189,11 +189,22 @@ void IdentifierTable::AddKeywords(const LangOptions &LangOpts) {
 #include "clang/Basic/TokenKinds.def"
 }
 
+/// addOperatorPrefix - Add the prefix "operator" (possible with a
+/// space after it) to the given operator symbol, and return the
+/// result.
+static std::string addOperatorPrefix(const char* Symbol) {
+  std::string result = "operator";
+  if (Symbol[0] >= 'a' && Symbol[0] <= 'z')
+    result += ' ';
+  result += Symbol;
+  return result;
+}
+
 /// AddOverloadedOperators - Register the name of all C++ overloadable
 /// operators ("operator+", "operator[]", etc.)
 void IdentifierTable::AddOverloadedOperators() {
 #define OVERLOADED_OPERATOR(Name,Spelling,Token, Unary, Binary, MemberOnly) \
-  OverloadedOperators[OO_##Name] = &get(Spelling);                      \
+  OverloadedOperators[OO_##Name] = &get(addOperatorPrefix(Spelling));   \
   OverloadedOperators[OO_##Name]->setOverloadedOperatorID(OO_##Name);
 #include "clang/Basic/OperatorKinds.def"
 }