add __rvalue(expression) builtin

compiler/src/dmd/astbase.d

@@ -4548,6 +4548,7 @@ struct ASTBase
         EXP op;
         ubyte size;
         ubyte parens;
+        ubyte rvalue;              // consider this an rvalue, even if it is an lvalue
         Type type;
         Loc loc;
 

compiler/src/dmd/clone.d

@@ -1617,6 +1617,7 @@ private Statement generateCopyCtorBody(StructDeclaration sd)
  */
 bool needCopyCtor(StructDeclaration sd, out bool hasCpCtor)
 {
+    //printf("needCopyCtor() %s\n", sd.toChars());
     if (global.errors)
         return false;
 
@@ -1648,14 +1649,14 @@ bool needCopyCtor(StructDeclaration sd, out bool hasCpCtor)
             return 0;
         }
 
-        if (isRvalueConstructor(sd, ctorDecl))
+        if (ctorDecl.isMoveCtor)
             rvalueCtor = ctorDecl;
         return 0;
     });
 
     if (cpCtor)
     {
-        if (rvalueCtor)
+        if (0 && rvalueCtor)
         {
             .error(sd.loc, "`struct %s` may not define both a rvalue constructor and a copy constructor", sd.toChars());
             errorSupplemental(rvalueCtor.loc,"rvalue constructor defined here");

compiler/src/dmd/declaration.h

@@ -782,6 +782,7 @@ class CtorDeclaration final : public FuncDeclaration
 {
 public:
     d_bool isCpCtor;
+    d_bool isMoveCtor;
     CtorDeclaration *syntaxCopy(Dsymbol *) override;
     const char *kind() const override;
     const char *toChars() const override;

compiler/src/dmd/dscope.d

@@ -24,6 +24,7 @@ import dmd.dclass;
 import dmd.declaration;
 import dmd.dmodule;
 import dmd.doc;
+import dmd.dstruct;
 import dmd.dsymbol;
 import dmd.dsymbolsem;
 import dmd.dtemplate;
@@ -156,6 +157,7 @@ extern (C++) struct Scope
 
     AliasDeclaration aliasAsg; /// if set, then aliasAsg is being assigned a new value,
                                /// do not set wasRead for it
+    StructDeclaration argStruct;    /// elimiate recursion when looking for rvalue construction
 
     extern (D) __gshared Scope* freelist;
 

compiler/src/dmd/dsymbolsem.d

@@ -256,7 +256,7 @@ Return:
 */
 bool checkHasBothRvalueAndCpCtor(StructDeclaration sd, CtorDeclaration ctor, TemplateInstance ti)
 {
-    if (sd && sd.hasCopyCtor && isRvalueConstructor(sd, ctor))
+    if (sd && sd.hasCopyCtor && ctor.isMoveCtor)
     {
         .error(ctor.loc, "cannot define both an rvalue constructor and a copy constructor for `struct %s`", sd.toChars());
         .errorSupplemental(ti.loc, "Template instance `%s` creates an rvalue constructor for `struct %s`",
@@ -268,31 +268,6 @@ bool checkHasBothRvalueAndCpCtor(StructDeclaration sd, CtorDeclaration ctor, Tem
     return false;
 }
 
-/************************************************
- * Check if ctor is an rvalue constructor.
- * A constructor that receives a single parameter of the same type as
- * `Unqual!typeof(this)` is an rvalue constructor.
- * Params:
- *      sd = struct that ctor is a member of
- *      ctor = constructor to test
- * Returns:
- *      true if it is an rvalue constructor
- */
-bool isRvalueConstructor(StructDeclaration sd, CtorDeclaration ctor)
-{
-    auto tf = ctor.type.isTypeFunction();
-    const dim = tf.parameterList.length;
-    if (dim == 1 || (dim > 1 && tf.parameterList[1].defaultArg))
-    {
-        auto param = tf.parameterList[0];
-        if (!(param.storageClass & STC.ref_) && param.type.mutableOf().unSharedOf() == sd.type.mutableOf().unSharedOf())
-        {
-            return true;
-        }
-    }
-    return false;
-}
-
 /*************************************
  * Find the `alias this` symbol of e's type.
  * Params:
@@ -2484,10 +2459,13 @@ private extern(C++) final class DsymbolSemanticVisitor : Visitor
             {
                 //printf("tf: %s\n", tf.toChars());
                 auto param = tf.parameterList[0];
-                if (param.storageClass & STC.ref_ && param.type.mutableOf().unSharedOf() == sd.type.mutableOf().unSharedOf())
+                if (param.type.mutableOf().unSharedOf() == sd.type.mutableOf().unSharedOf())
                 {
                     //printf("copy constructor\n");
-                    ctd.isCpCtor = true;
+                    if (param.storageClass & STC.ref_)
+                        ctd.isCpCtor = true;            // copy constructor
+                    else
+                        ctd.isMoveCtor = true;          // move constructor
                 }
             }
         }

compiler/src/dmd/e2ir.d

@@ -5532,6 +5532,8 @@ elem *callfunc(const ref Loc loc,
                     v = ve.var.isVarDeclaration();
                 bool copy = !(v && (v.isArgDtorVar || v.storage_class & STC.rvalue)); // copy unless the destructor is going to be run on it
                                                     // then assume the frontend took care of the copying and pass it by ref
+                if (arg.rvalue)                     // marked with __rvalue
+                    copy = false;
 
                 elems[i] = addressElem(ea, arg.type, copy);
                 continue;

compiler/src/dmd/expression.d

@@ -297,6 +297,7 @@ extern (C++) abstract class Expression : ASTNode
     Loc loc;        // file location
     const EXP op;   // to minimize use of dynamic_cast
     bool parens;    // if this is a parenthesized expression
+    bool rvalue;    // true if this is considered to be an rvalue, even if it is an lvalue
 
     extern (D) this(const ref Loc loc, EXP op) scope @safe
     {
@@ -1307,7 +1308,7 @@ extern (C++) class IdentifierExp : Expression
 
     override final bool isLvalue()
     {
-        return true;
+        return !this.rvalue;
     }
 
     override void accept(Visitor v)
@@ -1351,7 +1352,7 @@ extern (C++) final class DsymbolExp : Expression
 
     override bool isLvalue()
     {
-        return true;
+        return !rvalue;
     }
 
     override void accept(Visitor v)
@@ -1397,7 +1398,7 @@ extern (C++) class ThisExp : Expression
     override final bool isLvalue()
     {
         // Class `this` should be an rvalue; struct `this` should be an lvalue.
-        return type.toBasetype().ty != Tclass;
+        return !rvalue && type.toBasetype().ty != Tclass;
     }
 
     override void accept(Visitor v)
@@ -1782,7 +1783,7 @@ extern (C++) final class StringExp : Expression
         /* string literal is rvalue in default, but
          * conversion to reference of static array is only allowed.
          */
-        return (type && type.toBasetype().ty == Tsarray);
+        return !rvalue && (type && type.toBasetype().ty == Tsarray);
     }
 
     /********************************
@@ -2719,7 +2720,7 @@ extern (C++) final class VarExp : SymbolExp
 
     override bool isLvalue()
     {
-        if (var.storage_class & (STC.lazy_ | STC.rvalue | STC.manifest))
+        if (rvalue || var.storage_class & (STC.lazy_ | STC.rvalue | STC.manifest))
             return false;
         return true;
     }
@@ -3098,7 +3099,7 @@ extern (C++) class BinAssignExp : BinExp
 
     override final bool isLvalue()
     {
-        return true;
+        return !rvalue;
     }
 
     override void accept(Visitor v)
@@ -3303,6 +3304,8 @@ extern (C++) final class DotVarExp : UnaExp
 
     override bool isLvalue()
     {
+        if (rvalue)
+            return false;
         if (e1.op != EXP.structLiteral)
             return true;
         auto vd = var.isVarDeclaration();
@@ -3530,6 +3533,8 @@ extern (C++) final class CallExp : UnaExp
 
     override bool isLvalue()
     {
+        if (rvalue)
+            return false;
         Type tb = e1.type.toBasetype();
         if (tb.ty == Tdelegate || tb.ty == Tpointer)
             tb = tb.nextOf();
@@ -3648,7 +3653,7 @@ extern (C++) final class PtrExp : UnaExp
 
     override bool isLvalue()
     {
-        return true;
+        return !rvalue;
     }
 
     override void accept(Visitor v)
@@ -3777,7 +3782,7 @@ extern (C++) final class CastExp : UnaExp
     override bool isLvalue()
     {
         //printf("e1.type = %s, to.type = %s\n", e1.type.toChars(), to.toChars());
-        if (!e1.isLvalue())
+        if (rvalue || !e1.isLvalue())
             return false;
         return (to.ty == Tsarray && (e1.type.ty == Tvector || e1.type.ty == Tsarray)) ||
             e1.type.mutableOf.unSharedOf().equals(to.mutableOf().unSharedOf());
@@ -3834,7 +3839,7 @@ extern (C++) final class VectorArrayExp : UnaExp
 
     override bool isLvalue()
     {
-        return e1.isLvalue();
+        return !rvalue && e1.isLvalue();
     }
 
     override void accept(Visitor v)
@@ -3891,7 +3896,7 @@ extern (C++) final class SliceExp : UnaExp
         /* slice expression is rvalue in default, but
          * conversion to reference of static array is only allowed.
          */
-        return (type && type.toBasetype().ty == Tsarray);
+        return !rvalue && (type && type.toBasetype().ty == Tsarray);
     }
 
     override Optional!bool toBool()
@@ -3956,6 +3961,8 @@ extern (C++) final class ArrayExp : UnaExp
 
     override bool isLvalue()
     {
+        if (rvalue)
+            return false;
         if (type && type.toBasetype().ty == Tvoid)
             return false;
         return true;
@@ -4005,7 +4012,7 @@ extern (C++) final class CommaExp : BinExp
 
     override bool isLvalue()
     {
-        return e2.isLvalue();
+        return !rvalue && e2.isLvalue();
     }
 
     override Optional!bool toBool()
@@ -4080,7 +4087,7 @@ extern (C++) final class DelegatePtrExp : UnaExp
 
     override bool isLvalue()
     {
-        return e1.isLvalue();
+        return !rvalue && e1.isLvalue();
     }
 
     override void accept(Visitor v)
@@ -4103,7 +4110,7 @@ extern (C++) final class DelegateFuncptrExp : UnaExp
 
     override bool isLvalue()
     {
-        return e1.isLvalue();
+        return !rvalue && e1.isLvalue();
     }
 
     override void accept(Visitor v)
@@ -4143,6 +4150,8 @@ extern (C++) final class IndexExp : BinExp
 
     override bool isLvalue()
     {
+        if (rvalue)
+            return false;
         auto t1b = e1.type.toBasetype();
         if (t1b.isTypeAArray() || t1b.isTypeSArray() ||
             (e1.isIndexExp() && t1b != t1b.isTypeDArray()))
@@ -4251,7 +4260,7 @@ extern (C++) class AssignExp : BinExp
         {
             return false;
         }
-        return true;
+        return !rvalue;
     }
 
     override void accept(Visitor v)
@@ -4982,7 +4991,7 @@ extern (C++) final class CondExp : BinExp
 
     override bool isLvalue()
     {
-        return e1.isLvalue() && e2.isLvalue();
+        return !rvalue && e1.isLvalue() && e2.isLvalue();
     }
 
     override void accept(Visitor v)

compiler/src/dmd/expression.h

@@ -78,6 +78,7 @@ class Expression : public ASTNode
     Loc loc;                    // file location
     EXP op;                     // to minimize use of dynamic_cast
     d_bool parens;              // if this is a parenthesized expression
+    d_bool rvalue;              // consider this an rvalue, even if it is an lvalue
 
     size_t size() const;
     static void _init();

compiler/src/dmd/expressionsem.d

@@ -846,6 +846,7 @@ extern (D) Expression doCopyOrMove(Scope *sc, Expression e, Type t = null)
  */
 private Expression callCpCtor(Scope* sc, Expression e, Type destinationType)
 {
+    //printf("callCpCtor(e: %s et: %s destinationType: %s\n", toChars(e), toChars(e.type), toChars(destinationType));
     auto ts = e.type.baseElemOf().isTypeStruct();
 
     if (!ts)
@@ -860,6 +861,13 @@ private Expression callCpCtor(Scope* sc, Expression e, Type destinationType)
      * This is not the most efficient, ideally tmp would be constructed
      * directly onto the stack.
      */
+static if (0) printf("copyToTemp\n");
+{
+    import core.stdc.stdlib;
+    __gshared int x;
+    if (++x == 3)
+        exit(1);
+}
     auto tmp = copyToTemp(STC.rvalue, "__copytmp", e);
     if (sd.hasCopyCtor && destinationType)
     {
@@ -2952,7 +2960,7 @@ private bool functionParameters(const ref Loc loc, Scope* sc,
     Type* prettype, Expression* peprefix)
 {
     Expressions* arguments = argumentList.arguments;
-    //printf("functionParameters() %s\n", fd ? fd.toChars() : "");
+    //printf("functionParameters() fd: %s tf: %s\n", fd ? fd.ident.toChars() : "", toChars(tf));
     assert(arguments);
     assert(fd || tf.next);
     const size_t nparams = tf.parameterList.length;
@@ -3892,6 +3900,8 @@ private extern (C++) final class ExpressionSemanticVisitor : Visitor
             return;
         }
 
+        scope (success) result.rvalue = exp.rvalue;
+
         Dsymbol scopesym;
         Dsymbol s = sc.search(exp.loc, exp.ident, scopesym);
         if (s)
@@ -6725,7 +6735,7 @@ private extern (C++) final class ExpressionSemanticVisitor : Visitor
                     errorSupplemental(exp.loc, "%s", failMessage);
             }
 
-            if (tf.callMatch(null, exp.argumentList, 0, &errorHelper, sc) == MATCH.nomatch)
+            if (callMatch(exp.f, tf, null, exp.argumentList, 0, &errorHelper, sc) == MATCH.nomatch)
                 return setError();
 
             // Purity and safety check should run after testing arguments matching
@@ -6808,7 +6818,7 @@ private extern (C++) final class ExpressionSemanticVisitor : Visitor
                     exp.f = null;
                 }
 
-                if (tf.callMatch(null, exp.argumentList, 0, &errorHelper2, sc) == MATCH.nomatch)
+                if (callMatch(exp.f, tf, null, exp.argumentList, 0, &errorHelper2, sc) == MATCH.nomatch)
                     exp.f = null;
             }
             if (!exp.f || exp.f.errors)