Support type(expression) operator, #1650.

Changes

@@ -11,19 +11,21 @@ The contributors that suggested a given feature are shown in []. Thanks!
 
 ***   Verilation speed improvements, #2133, #2138. [Geza Lore]
 
-***   Support libgoogle-perftools-dev's libtcmalloc if available. #2137. [Geza Lore]
+***   Support libgoogle-perftools-dev's libtcmalloc if available, #2137. [Geza Lore]
 
-***   Support $readmem/$writemem with assoc arrarys. Closes #2100. [agrobman]
+***   Support $readmem/$writemem with assoc arrarys, #2100. [agrobman]
 
-****  Support left justified $display. Closes #2101. [Pieter Kapsenberg]
+****  Support type(expression) operator, #1650.
+
+****  Support left justified $display, #2101. [Pieter Kapsenberg]
 
 ****  Add parameter values in XML. #2110. [Pieter Kapsenberg]
 
-****  Add loc column location in XML (replaces fl). #2122. [Pieter Kapsenberg]
+****  Add loc column location in XML (replaces fl), #2122. [Pieter Kapsenberg]
 
 ****  Add error on misused define. [Topa Tota]
 
-****  Add parameter to set maximum signal width. #2082. [Øyvind Harboe]
+****  Add parameter to set maximum signal width, #2082. [Øyvind Harboe]
 
 ****  Fix VPI scope naming for public modules. [Nandu Raj]
 

src/V3AstNodes.h

@@ -859,6 +859,11 @@ public:
         dtypeFrom(defp->dtypep());
         widthFromSub(subDTypep());
     }
+    class FlagTypeOfExpr {};  // type(expr) for parser only
+    AstRefDType(FileLine* fl, FlagTypeOfExpr, AstNode* typeofp)
+        : ASTGEN_SUPER(fl), m_refDTypep(NULL), m_packagep(NULL) {
+        setOp2p(typeofp);
+    }
     ASTNODE_NODE_FUNCS(RefDType)
     // METHODS
     virtual const char* broken() const { BROKEN_RTN(m_refDTypep && !m_refDTypep->brokeExists()); return NULL; }
@@ -901,6 +906,7 @@ public:
     virtual AstNodeDType* subDTypep() const { return m_refDTypep; }
     AstPackage* packagep() const { return m_packagep; }
     void packagep(AstPackage* nodep) { m_packagep = nodep; }
+    AstNode* typeofp() const { return op2p(); }
 };
 
 class AstStructDType : public AstNodeUOrStructDType {

src/V3LinkDot.cpp

@@ -2487,7 +2487,8 @@ private:
         } else {
             checkNoDot(nodep);
         }
-        if (!nodep->defp()) {
+        if (nodep->typeofp()) {  // Really is a typeof not a reference
+        } else if (!nodep->defp()) {
             VSymEnt* foundp;
             if (nodep->packagep()) {
                 foundp = m_statep->getNodeSym(nodep->packagep())->findIdFlat(nodep->name());

src/V3Width.cpp

@@ -1261,6 +1261,15 @@ private:
         }
         if (nodep->didWidthAndSet()) return;  // This node is a dtype & not both PRELIMed+FINALed
         nodep->doingWidth(true);
+        if (nodep->typeofp()) {  // type(typeofp_expression)
+            // Type comes from expression's type
+            userIterateAndNext(nodep->typeofp(), WidthVP(SELF, BOTH).p());
+            AstNode* typeofp = nodep->typeofp();
+            nodep->refDTypep(typeofp->dtypep());
+            VL_DO_DANGLING(typeofp->unlinkFrBack()->deleteTree(), typeofp);
+            // We had to use AstRefDType for this construct as pointers to this type
+            // in type table are still correct (which they wouldn't be if we replaced the node)
+        }
         userIterateChildren(nodep, NULL);
         if (nodep->subDTypep()) nodep->refDTypep(iterateEditDTypep(nodep, nodep->subDTypep()));
         // Effectively nodep->dtypeFrom(nodep->dtypeSkipRefp());
@@ -4175,7 +4184,7 @@ private:
     AstNode* spliceCvtD(AstNode* nodep) {
         // For integer used in REAL context, convert to real
         // We don't warn here, "2.0 * 2" is common and reasonable
-        if (nodep && !nodep->isDouble()) {
+        if (nodep && !nodep->dtypep()->skipRefp()->isDouble()) {
             UINFO(6,"   spliceCvtD: "<<nodep<<endl);
             AstNRelinker linker;
             nodep->unlinkFrBack(&linker);
@@ -4189,7 +4198,7 @@ private:
     AstNode* spliceCvtS(AstNode* nodep, bool warnOn) {
         // IEEE-2012 11.8.1: Signed: Type coercion creates signed
         // 11.8.2: Argument to convert is self-determined
-        if (nodep && nodep->isDouble()) {
+        if (nodep && nodep->dtypep()->skipRefp()->isDouble()) {
             UINFO(6,"   spliceCvtS: "<<nodep<<endl);
             AstNRelinker linker;
             nodep->unlinkFrBack(&linker);

src/verilog.y

@@ -1566,7 +1566,7 @@ data_typeNoRef<dtypep>:		// ==IEEE: data_type, excluding class_type etc referenc
 	//			// instead see data_typeVar
 	|	yVIRTUAL__INTERFACE yINTERFACE id/*interface*/	{ $$ = NULL; BBUNSUP($1, "Unsupported: virtual interface"); }
 	|	yVIRTUAL__anyID                id/*interface*/	{ $$ = NULL; BBUNSUP($1, "Unsupported: virtual data type"); }
-	//UNSUP	type_reference				{ UNSUP }
+	|	type_reference				{ $$ = $1; }
 	//			// IEEE: class_scope: see data_type above
 	//			// IEEE: class_type: see data_type above
 	//			// IEEE: ps_covergroup: see data_type above
@@ -1583,9 +1583,9 @@ var_data_type<dtypep>:		// ==IEEE: var_data_type
 	|	yVAR implicit_typeE			{ $$ = $2; }
 	;
 
-//UNSUP type_reference<dtypep>:  // ==IEEE: type_reference
+type_reference<dtypep>:  	// ==IEEE: type_reference
-//UNSUP		yTYPE '(' exprOrDataType ')'		{ UNSUP }
+		yTYPE '(' exprOrDataType ')'		{ $$ = new AstRefDType($1, AstRefDType::FlagTypeOfExpr(), $3); }
-//UNSUP	;
+	;
 
 struct_unionDecl<uorstructp>:	// IEEE: part of data_type
 	//			// packedSigningE is NOP for unpacked

test_regress/t/t_type.pl

@@ -0,0 +1,20 @@
+#!/usr/bin/perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2004 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+
+scenarios(simulator => 1);
+
+compile(
+    );
+
+execute(
+    check_finished => 1,
+    );
+
+ok(1);
+1;

test_regress/t/t_type.v

@@ -0,0 +1,21 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2020 by Wilson Snyder.
+
+module t(/*AUTOARG*/);
+
+   real x;
+   real y;
+   var type(x+y) z;
+
+   initial begin
+      x = 1.2;
+      y = 2.3;
+      z = x + y;
+      if (z != (1.2+2.3)) $stop;
+      $write("*-* All Finished *-*\n");
+      $finish;
+   end
+
+endmodule