Support for-loop increments with commas.

Changes

@@ -5,12 +5,14 @@ The contributors that suggested a given feature are shown in []. Thanks!
 
 * Verilator 4.037 devel
 
-*** Support VPI access to parameters and localparam. [Ludwig Rogiers]
+***   Support VPI access to parameters and localparam. [Ludwig Rogiers]
 
 ****  Add new UNSUPPORTED error code to replace most previous Unsupported: messages.
 
 ****  With --bbox-unsup continue parsing on many (not all) UVM constructs.
 
+****  Support for-loop increments with commas.
+
 ****  Fix to flush FST trace on termination due to $stop or assertion failure.
 
 ****  Fix part select error when multipling by power-of-two (#2413). [Conor McCullough]

src/V3LinkDot.cpp

@@ -2027,6 +2027,12 @@ private:
         // Generally resolved during Primay, but might be at param time under AstUnlinkedRef
         UASSERT_OBJ(m_statep->forPrimary() || m_statep->forPrearray(), nodep,
                     "ParseRefs should no longer exist");
+        if (nodep->name() == "this") {
+            nodep->v3warn(E_UNSUPPORTED, "Unsupported: this");
+        }
+        else if (nodep->name() == "super") {
+            nodep->v3warn(E_UNSUPPORTED, "Unsupported: super");
+        }
         DotStates lastStates = m_ds;
         bool start = (m_ds.m_dotPos == DP_NONE);  // Save, as m_dotp will be changed
         if (start) {

src/V3Unroll.cpp

@@ -113,7 +113,7 @@ private:
         // Assignment of next value check
         AstAssign* incAssp = VN_CAST(incp, Assign);
         if (!incAssp) return cantUnroll(nodep, "no increment assignment");
-        UASSERT_OBJ(!incAssp->nextp(), nodep, "increment shouldn't be a list");
+        if (incAssp->nextp()) return cantUnroll(nodep, "multiple increments");
 
         m_forVarp = VN_CAST(initAssp->lhsp(), VarRef)->varp();
         m_forVscp = VN_CAST(initAssp->lhsp(), VarRef)->varScopep();

src/verilog.y

@@ -3376,7 +3376,7 @@ for_stepE<nodep>:		// IEEE: for_step + empty
 
 for_step<nodep>:		// IEEE: for_step
 		for_step_assignment			{ $$ = $1; }
-	|	for_step ',' for_step_assignment	{ $$ = $1; BBUNSUP($2, "Unsupported: for loop step after the first comma"); }
+	|	for_step ',' for_step_assignment	{ $$ = AstNode::addNextNull($1, $3); }
 	;
 
 for_step_assignment<nodep>:  // ==IEEE: for_step_assignment

test_regress/t/t_for_comma_bad.out

@@ -1,18 +1,3 @@
-%Error-UNSUPPORTED: t/t_for_comma_bad.v:14:21: Unsupported: for loop step after the first comma
-   14 |       for (; ; a=a+1, b=b+1) ;
-      |                     ^
-%Error-UNSUPPORTED: t/t_for_comma_bad.v:17:24: Unsupported: for loop step after the first comma
-   17 |       for (; a<1; a=a+1, b=b+1) ;
-      |                        ^
-%Error-UNSUPPORTED: t/t_for_comma_bad.v:20:27: Unsupported: for loop step after the first comma
-   20 |       for (a=0; a<1; a=a+1, b=b+1) ;
-      |                           ^
-%Error-UNSUPPORTED: t/t_for_comma_bad.v:23:35: Unsupported: for loop step after the first comma
-   23 |       for (integer a=0; a<1; a=a+1, b=b+1) ;
-      |                                   ^
-%Error-UNSUPPORTED: t/t_for_comma_bad.v:26:39: Unsupported: for loop step after the first comma
-   26 |       for (var integer a=0; a<1; a=a+1, b=b+1) ;
-      |                                       ^
 %Error-UNSUPPORTED: t/t_for_comma_bad.v:27:23: Unsupported: for loop initialization after the first comma
    27 |       for (integer a=0, integer b=0; a<1; ) ;
       |                       ^
@@ -22,7 +7,4 @@
 %Error-UNSUPPORTED: t/t_for_comma_bad.v:29:23: Unsupported: for loop initialization after the first comma
    29 |       for (integer a=0, integer b=0; a<1; a=a+1, b=b+1) ;
       |                       ^
-%Error-UNSUPPORTED: t/t_for_comma_bad.v:29:48: Unsupported: for loop step after the first comma
-   29 |       for (integer a=0, integer b=0; a<1; a=a+1, b=b+1) ;
-      |                                                ^
 %Error: Exiting due to

test_regress/t/t_for_loop.v

@@ -101,6 +101,13 @@ module t (/*AUTOARG*/
 	 if (i != 20) $stop;
 	 for (i=30; i<10; i++) ;
 	 if (i != 30) $stop;
+	 // Comma
+	 loops = 0;
+	 for (i=0; i<20; ++i, ++loops);
+	 if (loops !== 20) $stop;
+	 loops = 0;
+	 for (i=0; i<20; ++loops, ++i);
+	 if (loops !== 20) $stop;
 	 //
 	 $write("*-* All Finished *-*\n");
 	 $finish;