[cfe-dev] Allow implicit copy constructor between address spaces in C++

[Adam Strzelecki]

Unfortunately it doesn’t work for me. Clang throws an assertion about what I should do, while I am trying do exactly opposite  :>

clang-3.5: /home/ono/Projects/llvm/tools/clang/lib/AST/ExprClassification.cpp:619: clang::Expr::Classification::ModifiableType IsModifiable(clang::ASTContext&, const clang::Expr*, clang::Expr::Classification::Kinds, clang::SourceLocation&): Assertion `(E->getObjectKind() == OK_ObjCProperty || !Ctx.getLangOpts().CPlusPlus) && "C++ struct assignment should be resolved by the " "copy assignment operator."' failed.

Code I am testing on:

typedef struct Point { float x, y; } Point;
float test(int i, //
           __attribute__((address_space(1))) const Point *in,
           __attribute__((address_space(1))) Point *out) {
  Point r;
  __builtin_assign(r, in[i]);
  out[i] = r;
  return r.x * r.y;
}

Change proposed by Alp:

--- a/include/clang/Basic/Builtins.def
+++ b/include/clang/Basic/Builtins.def
@@ -1204,6 +1204,7 @@ BUILTIN(__builtin_smulll_overflow, "bSLLiCSLLiCSLLi*", "n")
 
 // Clang builtins (not available in GCC).
 BUILTIN(__builtin_addressof, "v*v&", "nct")
+BUILTIN(__builtin_assign, "v.", "t")
 
 #undef BUILTIN
 #undef LIBBUILTIN
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -296,6 +296,12 @@ Sema::CheckBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
     if (SemaBuiltinAddressof(*this, TheCall))
       return ExprError();
     break;
+  case Builtin::BI__builtin_assign:
+    if (checkArgCount(*this, TheCall, 2))
+      return true;
+    return CreateBuiltinBinOp(TheCall->getLocStart(), BO_Assign,
+                              TheCall->getArg(0), TheCall->getArg(1));
+    break;
   }