Refactor: Extract combine and extractLast from Expression AST node to semantic layer

compiler/src/dmd/clone.d

@@ -342,7 +342,7 @@ FuncDeclaration buildOpAssign(StructDeclaration sd, Scope* sc)
             e4 = new BlitExp(loc, new IdentifierExp(loc, Id.p), new VarExp(loc, swap));
         }
 
-        e = Expression.combine(e1, e2, e3, e4);
+        e = combine(e1, e2, e3, e4);
     }
     /* postblit was called when the value was passed to opAssign, we just need to blit the result */
     else if (sd.postblit)
@@ -367,7 +367,7 @@ FuncDeclaration buildOpAssign(StructDeclaration sd, Scope* sc)
             auto ec = new AssignExp(loc,
                 new DotVarExp(loc, new ThisExp(loc), v),
                 new DotVarExp(loc, new IdentifierExp(loc, Id.p), v));
-            e = Expression.combine(e, ec);
+            e = combine(e, ec);
         }
     }
     if (e)
@@ -991,7 +991,7 @@ void buildDtors(AggregateDeclaration ad, Scope* sc)
 
                 ex = new CallExp(loc, new IdentifierExp(loc, Id.__ArrayDtor), se);
             }
-            e = Expression.combine(ex, e); // combine in reverse order
+            e = combine(ex, e); // combine in reverse order
         }
 
         if (e || (stc & STC.disable))
@@ -1051,7 +1051,7 @@ void buildDtors(AggregateDeclaration ad, Scope* sc)
             ex = new DotVarExp(loc, ex, fd, false);
             CallExp ce = new CallExp(loc, ex);
             ce.directcall = true;
-            e = Expression.combine(e, ce);
+            e = combine(e, ce);
         }
         auto dd = new DtorDeclaration(declLoc, Loc.initial, stc, Id.__aggrDtor);
         dd.isGenerated = true;
@@ -1248,7 +1248,7 @@ FuncDeclaration buildInv(AggregateDeclaration ad, Scope* sc)
                     break;
                 }
             }
-            e = Expression.combine(e, new CallExp(Loc.initial, new VarExp(Loc.initial, inv, false)));
+            e = combine(e, new CallExp(Loc.initial, new VarExp(Loc.initial, inv, false)));
         }
         auto inv = new InvariantDeclaration(ad.loc, Loc.initial, stc | stcx,
                 Id.classInvariant, new ExpStatement(Loc.initial, e));
@@ -1501,7 +1501,7 @@ FuncDeclaration buildPostBlit(StructDeclaration sd, Scope* sc)
             Expression ex = new ThisExp(loc);
             ex = new DotVarExp(loc, ex, fd, false);
             ex = new CallExp(loc, ex);
-            e = Expression.combine(e, ex);
+            e = combine(e, ex);
         }
 
         checkShared();
@@ -1606,7 +1606,7 @@ private Statement generateCtorBody(StructDeclaration sd, bool move)
         auto ec = new AssignExp(loc,
             new DotVarExp(loc, new ThisExp(loc), v),
             rhs);
-        e = Expression.combine(e, ec);
+        e = combine(e, ec);
         //printf("e.toChars = %s\n", e.toChars());
     }
     Statement s1 = new ExpStatement(loc, e);

compiler/src/dmd/dcast.d

@@ -3181,7 +3181,7 @@ Expression castTo(Expression e, Scope* sc, Type t, Type att = null)
         }
 
         auto ini = t.defaultInitLiteral(e.loc);
-        return Expression.combine(e, ini);
+        return combine(e, ini);
     }
 
     switch (e.op)
@@ -4593,5 +4593,5 @@ IntRange getIntRange(Expression e)
  */
 Expression specialNoreturnCast(Expression toBeCasted, Type to)
 {
-    return Expression.combine(toBeCasted, to.defaultInitLiteral(toBeCasted.loc));
+    return combine(toBeCasted, to.defaultInitLiteral(toBeCasted.loc));
 }

compiler/src/dmd/dsymbolsem.d

@@ -2406,7 +2406,7 @@ private extern(C++) final class DsymbolSemanticVisitor : Visitor
 
                         iexps.remove(pos);
                         iexps.insert(pos, te.exps);
-                        (*iexps)[pos] = Expression.combine(te.e0, (*iexps)[pos]);
+                        (*iexps)[pos] = combine(te.e0, (*iexps)[pos]);
                         goto Lexpand1;
                     }
                     else if (isAliasThisTuple(e))
@@ -2488,7 +2488,7 @@ private extern(C++) final class DsymbolSemanticVisitor : Visitor
                     {
                         einit = (*te.exps)[i];
                         if (i == 0)
-                            einit = Expression.combine(te.e0, einit);
+                            einit = combine(te.e0, einit);
                     }
                     // Use the original initializer location, not the tuple element's location,
                     // so error messages point to the declaration site

compiler/src/dmd/expression.d

@@ -215,70 +215,6 @@ extern (C++) abstract class Expression : ASTNode
         return .toChars(this);
     }
 
-    /**********************************
-     * Combine e1 and e2 by CommaExp if both are not NULL.
-     */
-    extern (D) static Expression combine(Expression e1, Expression e2) @safe
-    {
-        if (e1)
-        {
-            if (e2)
-            {
-                e1 = new CommaExp(e1.loc, e1, e2);
-                e1.type = e2.type;
-            }
-        }
-        else
-            e1 = e2;
-        return e1;
-    }
-
-    extern (D) static Expression combine(Expression e1, Expression e2, Expression e3) @safe
-    {
-        return combine(combine(e1, e2), e3);
-    }
-
-    extern (D) static Expression combine(Expression e1, Expression e2, Expression e3, Expression e4) @safe
-    {
-        return combine(combine(e1, e2), combine(e3, e4));
-    }
-
-    /**********************************
-     * If 'e' is a tree of commas, returns the rightmost expression
-     * by stripping off it from the tree. The remained part of the tree
-     * is returned via e0.
-     * Otherwise 'e' is directly returned and e0 is set to NULL.
-     */
-    extern (D) static Expression extractLast(Expression e, out Expression e0) @trusted
-    {
-        if (e.op != EXP.comma)
-        {
-            return e;
-        }
-
-        CommaExp ce = cast(CommaExp)e;
-        if (ce.e2.op != EXP.comma)
-        {
-            e0 = ce.e1;
-            return ce.e2;
-        }
-        else
-        {
-            e0 = e;
-
-            Expression* pce = &ce.e2;
-            while ((cast(CommaExp)(*pce)).e2.op == EXP.comma)
-            {
-                pce = &(cast(CommaExp)(*pce)).e2;
-            }
-            assert((*pce).op == EXP.comma);
-            ce = cast(CommaExp)(*pce);
-            *pce = ce.e1;
-
-            return ce.e2;
-        }
-    }
-
     extern (D) static Expressions* arraySyntaxCopy(Expressions* exps)
     {
         Expressions* a = null;