Fix inout task arguments

git-svn-id: file://localhost/svn/verilator/trunk/verilator@795 77ca24e4-aefa-0310-84f0-b9a241c72d87

Changes

@@ -5,6 +5,8 @@ indicates the contributor was also the author of the fix; Thanks!
 
 * Verilator 3.61*
 
+***  Support simple inout task ports.  [Eugene Weber]
+
 ***  Allow overriding Perl, Flex and Bison versions.  [by Robert Farrell]
 
 **** Default make no longer makes the docs; if you edit the documentation

src/V3AstNodes.cpp

@@ -85,7 +85,7 @@ int AstVar::widthTotalBytes() const {
 }
 
 string AstVar::verilogKwd() const {
-    if (isTristate()) {
+    if (isInout()) {
 	return "inout";
     } else if (isInput()) {
 	return "input";
@@ -93,6 +93,8 @@ string AstVar::verilogKwd() const {
 	return "output";
     } else if (isInteger()) {
 	return "integer";
+    } else if (isTristate()) {
+	return "tri";
     } else if (varType()==AstVarType::WIRE) {
 	return "wire";
     } else {
@@ -325,9 +327,12 @@ void AstVarRef::dump(ostream& str) {
 void AstVar::dump(ostream& str) {
     this->AstNode::dump(str);
     if (isSc()) str<<" [SC]";
-    if (isInput()) str<<" [I]";
+    if (isPrimaryIO()) str<<(isInout()?" [PIO]":(isInput()?" [PI]":" [PO]"));
-    if (isPrimaryIO()) str<<(isInput()?" [PI]":" [PO]");
+    else {
-    if (isOutput()) str<<" [O]";
+	if (isInout()) str<<" [IO]";
+	else if (isInput()) str<<" [I]";
+	else if (isOutput()) str<<" [O]";
+    }
     if (isUsedClock()) str<<" [C]";
     if (isSigPublic()) str<<" [P]";
     if (attrClockEn()) str<<" [aCLKEN]";

src/V3AstNodes.h

@@ -314,10 +314,13 @@ public:
     void 	name(const string& name) 	{ m_name = name; }
     bool	isInput() const { return m_input; }
     bool	isOutput() const { return m_output; }
-    bool	isTristate() const  { return (m_tristate); }
+    bool	isInOnly() const { return m_input && !m_output; }
+    bool	isOutOnly() const { return m_output && !m_input; }
+    bool	isInout() const { return m_input && m_output; }
+    bool	isTristate() const  { return m_tristate; }
     bool	isPrimaryIO() const { return m_primaryIO; }
     bool	isPrimaryIn() const { return isPrimaryIO() && isInput(); }
-    bool	isIO() const  { return (m_input||m_output||m_tristate); }
+    bool	isIO() const  { return (m_input||m_output); }
     bool	isSignal() const  { return (varType()==AstVarType::WIRE || varType()==AstVarType::IMPLICIT
 					    || varType()==AstVarType::REG || varType()==AstVarType::INTEGER); }
     bool	isTemp() const { return (varType()==AstVarType::BLOCKTEMP || varType()==AstVarType::MODULETEMP

src/V3EmitC.cpp

@@ -702,7 +702,7 @@ void EmitCStmts::emitVarDecl(AstVar* nodep, const string& prefixIfImp) {
 	    if (nodep->attrScClocked() && nodep->isInput()) {
 		puts("sc_in_clk\t");
 	    } else {
-		if (nodep->isTristate()) puts("sc_inout<");
+		if (nodep->isInout()) puts("sc_inout<");
 		else if (nodep->isInput()) puts("sc_in<");
 		else if (nodep->isOutput()) puts("sc_out<");
 		else nodep->v3fatalSrc("Unknown type");
@@ -714,7 +714,7 @@ void EmitCStmts::emitVarDecl(AstVar* nodep, const string& prefixIfImp) {
 	    puts(";\n");
 	} else { // C++ signals
 	    ofp()->putAlign(nodep->isStatic(), nodep->widthAlignBytes());
-	    if (nodep->isTristate()) puts("VL_INOUT");
+	    if (nodep->isInout()) puts("VL_INOUT");
 	    else if (nodep->isInput()) puts("VL_IN");
 	    else if (nodep->isOutput()) puts("VL_OUT");
 	    else nodep->v3fatalSrc("Unknown type");

src/V3Inst.cpp

@@ -79,7 +79,7 @@ private:
 	//	      or  ASSIGNW(expr,VARXREF(p))    (if sub's output)
 	UINFO(4,"   PIN  "<<nodep<<endl);
 	if (debug()>=9) nodep->dumpTree(cout,"  Pin_oldb: ");
-	if (nodep->modVarp()->isOutput() && nodep->exprp()->castConst())
+	if (nodep->modVarp()->isOutOnly() && nodep->exprp()->castConst())
 	    nodep->v3error("Output pin is assigned to a constant, electrical short");
 	// Use userp on the PIN to indicate we created an assign for this pin
 	if (!nodep->user()) {
@@ -90,7 +90,9 @@ private:
 	    AstNode*  exprp  = nodep->exprp()->cloneTree(false);
 	    if (nodep->width() != nodep->modVarp()->width())
 		nodep->v3fatalSrc("Width mismatch, should have been handled in pinReconnectSimple\n");
-	    if (nodep->modVarp()->isOutput()) {
+	    if (nodep->modVarp()->isInout()) {
+		nodep->v3fatalSrc("Unsupported: Verilator is a 2-state simulator");
+	    } else if (nodep->modVarp()->isOutput()) {
 		AstNode* rhsp = new AstVarXRef (exprp->fileline(), nodep->modVarp(), m_cellp->name(), false);
 		rhsp->widthSignedFrom(nodep);
 		AstAssignW* assp = new AstAssignW (exprp->fileline(), exprp, rhsp);
@@ -236,12 +238,14 @@ void V3Inst::pinReconnectSimple(AstPin* pinp, AstCell* cellp, AstModule* modp) {
     } else {
 	// Make a new temp wire
 	//if (1||debug()>=9) { pinp->dumpTree(cout,"in_pin:"); }
-	AstAssignW* assignp;
+	AstAssignW* assignp = NULL;
 	AstNode* pinexprp = pinp->exprp()->unlinkFrBack();
 	string newvarname = "__Vcellinp__"+cellp->name()+"__"+pinp->name();
 	AstVar* newvarp = new AstVar (pinVarp->fileline(), AstVarType::MODULETEMP, newvarname, pinVarp);
 	modp->addStmtp(newvarp);
-	if (pinVarp->isOutput()) {
+	if (pinVarp->isInout()) {
+	    pinVarp->v3fatalSrc("Unsupported: Inout connections to pins must be direct one-to-one connection (without any expression)");
+	} else if (pinVarp->isOutput()) {
 	    // See also V3Inst
 	    AstNode* rhsp = new AstVarRef(pinp->fileline(), newvarp, false);
 	    if (pinp->width() > rhsp->width()) {
@@ -265,7 +269,7 @@ void V3Inst::pinReconnectSimple(AstPin* pinp, AstCell* cellp, AstModule* modp) {
 	    pinp->exprp(new AstVarRef (pinexprp->fileline(), newvarp, false));
 	}
 	pinp->widthSignedFrom(pinp->exprp());
-	modp->addStmtp(assignp);
+	if (assignp) modp->addStmtp(assignp);
 	//if (1||debug()) { pinp->dumpTree(cout,"  out:"); }
 	//if (1||debug()) { assignp->dumpTree(cout," aout:"); }
     }

src/V3LinkLevel.cpp

@@ -140,7 +140,7 @@ void V3LinkLevel::wrapTop(AstNetlist* netlistp) {
 		AstVar* varp = oldvarp->cloneTree(false)->castVar();
 		newmodp->addStmtp(varp);
 		varp->sigPublic(true);	// User needs to be able to get to it...
-		if (oldvarp->isInput() || oldvarp->isOutput()) {
+		if (oldvarp->isIO()) {
 		    oldvarp->primaryIO(true);
 		    varp->primaryIO(true);
 		}

src/V3LinkResolve.cpp

@@ -111,7 +111,7 @@ private:
 	// VarRef: Resolve its reference
 	if (nodep->varp()) {
 	    nodep->varp()->usedParam(true);
-	    if (nodep->lvalue() && nodep->varp()->isInput()) {
+	    if (nodep->lvalue() && nodep->varp()->isInOnly()) {
 		nodep->v3error("Assigning to input variable: "<<nodep->prettyName());
 	    }
 	}

src/V3Task.cpp

@@ -227,8 +227,14 @@ private:
 		    nextpinp = pinp->nextp();
 		    pinp->unlinkFrBack();   // Relinked to assignment below
 		    //
-		    if (portp->isTristate()) {
+		    if (portp->isInout()) {
-			refp->v3error("Unsupported: Inouts in functions/tasks");
+			if (AstVarRef* varrefp = pinp->castVarRef()) {
+			    // Connect to this exact variable
+			    AstVarScope* localVscp = varrefp->varScopep(); if (!localVscp) varrefp->v3fatalSrc("Null var scope");
+			    portp->user2p(localVscp);
+			} else {
+			    pinp->v3error("Unsupported: Function/task input argument is not simple variable");
+			}
 		    }
 		    else if (portp->isOutput() && outvscp) {
 			refp->v3error("Outputs not allowed in function declarations");

test_regress/t/t_func.v

@@ -1,4 +1,4 @@
-// $Id:$
+// $Id$
 // DESCRIPTION: Verilator: Verilog Test module
 //
 // This file ONLY is placed into the Public Domain, for any use,
@@ -22,6 +22,12 @@ module t;
       if (global != 32'h17) $stop;
       nop(32'h11);
 
+      global = 32'h00000001;
+      flipbit(global,5'd8);
+      flipbit(global,5'd16);
+      flipbit(global,5'd24);
+      if (global !== 32'h01010101) $stop;
+
       $write("*-* All Finished *-*\n");
       $finish;
    end
@@ -70,4 +76,10 @@ module t;
       end
    endtask
 
+   task flipbit;
+      inout [31:0] vector;
+      input [4:0] bitnum;
+      vector[bitnum] = vector[bitnum] ^ 1'b1;
+   endtask
+
 endmodule