Support pattern assignments with data type labels, bug618.

Changes

@@ -5,9 +5,7 @@ indicates the contributor was also the author of the fix; Thanks!
 
 * Verilator 3.846-devel
 
-****  Support pattern assignments to const variables, bug616. [Ed Lander]
-
-****  Support pattern assignments in function calls, bug617. [Ed Lander]
+****  Support pattern assignment features, bug616, bug617, bug618. [Ed Lander]
 
 ****  Fix DETECTARRAY on packed structures, bug610. [Jeremy Bennett]
 

src/V3AstNodes.h

@@ -3999,7 +3999,7 @@ struct AstPattern : public AstNodeMath {
     // Parents: AstNodeAssign, AstPattern, ...
     // Children: expression, AstPattern, AstPatReplicate
     AstPattern(FileLine* fl, AstNode* itemsp) : AstNodeMath(fl) {
-	addNOp1p(itemsp);
+	addNOp2p(itemsp);
     }
     ASTNODE_NODE_FUNCS(Pattern, PATTERN)
     virtual string emitVerilog() { V3ERROR_NA; return ""; }  // Implemented specially
@@ -4008,7 +4008,11 @@ struct AstPattern : public AstNodeMath {
     virtual string emitSimpleOperator() { V3ERROR_NA; return "";}
     virtual bool cleanOut() {V3ERROR_NA; return "";}
     virtual int instrCount()	const { return widthInstrs(); }
-    AstNode* itemsp() const { return op1p(); } // op1 = AstPatReplicate, AstPatMember, etc
+    AstNodeDType* getChildDTypep() const { return childDTypep(); }
+    AstNodeDType* childDTypep() const { return op1p()->castNodeDType(); } // op1 = Type assigning to
+    void childDTypep(AstNodeDType* nodep) { setOp1p(nodep); }
+    AstNodeDType* subDTypep() const { return dtypep() ? dtypep() : childDTypep(); }
+    AstNode* itemsp() const { return op2p(); } // op2 = AstPatReplicate, AstPatMember, etc
 };
 struct AstPatMember : public AstNodeMath {
     // Verilog '{a} or '{a{b}}

src/V3ParseImp.h

@@ -77,6 +77,7 @@ struct V3ParseBisonYYSType {
 	AstPackageRef*	packagerefp;
 	AstParseRef*	parserefp;
 	AstPatMember*	patmemberp;
+	AstPattern*	patternp;
 	AstPin*		pinp;
 	AstRange*	rangep;
 	AstSenTree*	sentreep;

src/V3Width.cpp

@@ -1130,7 +1130,11 @@ private:
     virtual void visit(AstPattern* nodep, AstNUser* vup) {
 	if (nodep->didWidthAndSet()) return;
 	UINFO(9,"PATTERN "<<nodep<<endl);
-	AstNodeDType* vdtypep = vup->c()->dtypep();
+	if (nodep->childDTypep()) nodep->dtypep(moveChildDTypeEdit(nodep));  // data_type '{ pattern }
+	if (!nodep->dtypep() && vup->c()->dtypep()) {  // Get it from parent assignment/pin/etc
+	    nodep->dtypep(vup->c()->dtypep());
+	}
+	AstNodeDType* vdtypep = nodep->dtypep();
 	if (!vdtypep) nodep->v3error("Unsupported/Illegal: Assignment pattern member not underneath a supported construct: "<<nodep->backp()->prettyTypeName());
 	{
 	    vdtypep = vdtypep->skipRefp();

src/verilog.y

@@ -2313,7 +2313,7 @@ patternKey<nodep>:		// IEEE: merge structure_pattern_key, array_pattern_key, ass
 	|	yaID__ETC				{ $$ = new AstText($<fl>1,*$1); }
 	;
 
-assignment_pattern<nodep>:	// ==IEEE: assignment_pattern
+assignment_pattern<patternp>:	// ==IEEE: assignment_pattern
 	// This doesn't match the text of the spec.  I think a : is missing, or example code needed
 	// yP_TICKBRA constExpr exprList '}'	{ $$="'{"+$2+" "+$3"}"; }
 	//			// "'{ const_expression }" is same as patternList with one entry
@@ -2875,7 +2875,7 @@ exprOkLvalue<nodep>:		// expression that's also OK to use as a variable_lvalue
 	//			// IEEE: [ assignment_pattern_expression_type ] == [ ps_type_id /ps_paremeter_id/data_type]
 	//			// We allow more here than the spec requires
 	//UNSUP	~l~exprScope assignment_pattern		{ UNSUP }
-	//UNSUP	data_type assignment_pattern		{ UNSUP }
+	|	data_type assignment_pattern		{ $$ = $2; $2->childDTypep($1); }
 	|	assignment_pattern			{ $$ = $1; }
 	//
 	//UNSUP	streaming_concatenation			{ UNSUP }

test_regress/t/t_struct_init.v

@@ -41,6 +41,9 @@ module t;
 
    const b4_t b4_const_a = '{1'b1, 1'b0, 1'b0, 1'b1};
 
+   // Cast to a pattern - note bits are tagged out of order
+   const b4_t b4_const_b = b4_t'{ b1 : 1'b0, b0 : 1'b1, b3 : 1'b1, b2 : 1'b0 };
+
    wire b4_t b4_wire;
    assign b4_wire = '{1'b1, 1'b0, 1'b1, 1'b0};
 
@@ -100,6 +103,7 @@ module t;
       end
 
       if (b4_const_a != 4'b1001) $stop;
+      if (b4_const_b != 4'b1001) $stop;
       if (b4_wire != 4'b1010) $stop;
       if (pat(4'b1100, 4'b1100)) $stop;
       if (pat('{1'b1, 1'b0, 1'b1, 1'b1}, 4'b1011)) $stop;