DPI import: Allow system calls to call imports

bin/verilator

@@ -1148,6 +1148,14 @@ command line, or the link), you'd then:
     #include "Vour__Dpi.h"
     int add (int a, int b) { return a+b; }
 
+Verilator also extends the DPI format to allow using the same scheme to
+efficiently add system functions.  Simply use a dollar-sign prefixed system
+function name for the import, but note it must be escaped.
+
+   export "DPI-C" function integer \$myRand;
+
+   initial $display("myRand=%d", $myRand());
+
 =head1 CROSS COMPILATION
 
 Verilator supports cross-compiling Verilated code.  This is generally used

src/V3Ast.h

@@ -206,6 +206,8 @@ public:
     enum en {
 	BIT, BYTE, CHANDLE, INT, INTEGER, LOGIC, LONGINT,
 	REAL, REALTIME,	SHORTINT, SHORTREAL, TIME,
+	// Closer to a class type, but limited usage
+	STRING,
 	// Internal types
 	LOGIC_IMPLICIT
     };
@@ -214,6 +216,7 @@ public:
 	static const char* names[] = {
 	    "bit", "byte", "chandle", "int", "integer", "logic", "longint",
 	    "real", "realtime", "shortint", "shortreal", "time",
+	    "string",
 	    "LOGIC_IMPLICIT"
 	};
 	return names[m_e];
@@ -222,6 +225,7 @@ public:
 	static const char* names[] = {
 	    "unsigned char", "char", "void*", "int", "int", "svLogic", "long long",
 	    "double", "double", "short int", "float", "long long",
+	    "char*",
 	    ""
 	};
 	return names[m_e];
@@ -241,6 +245,7 @@ public:
 	case LONGINT:	return 64;
 	case SHORTINT:	return 16;
 	case TIME:	return 64;
+	case STRING:	return 64;  // Just the pointer, for today
 	default: return 0;
 	}
     }
@@ -251,7 +256,8 @@ public:
 	return m_e==INTEGER || m_e==LOGIC || m_e==LOGIC_IMPLICIT;
     }
     int isZeroInit() const { // Otherwise initializes to X
-	return m_e==BIT || m_e==BYTE || m_e==CHANDLE || m_e==INT || m_e==LONGINT || m_e==SHORTINT;
+	return (m_e==BIT || m_e==BYTE || m_e==CHANDLE || m_e==INT || m_e==LONGINT || m_e==SHORTINT
+		|| m_e==STRING);
     }
     int isSloppy() const { // Don't be as anal about width warnings
 	return !(m_e==LOGIC || m_e==BIT);
@@ -1250,7 +1256,6 @@ private:
     bool	m_dpiTask:1;	// DPI import task (vs. void function)
     bool	m_pure:1;	// DPI import pure
 public:
-    // Node that simply puts name into the output stream
     AstNodeFTask(FileLine* fileline, const string& name, AstNode* stmtsp)
 	: AstNode(fileline)
 	, m_name(name), m_taskPublic(false), m_didSigning(false)
@@ -1306,6 +1311,11 @@ public:
 	, m_taskp(NULL), m_packagep(NULL) {
 	setOp1p(namep);	addNOp2p(pinsp);
     }
+    AstNodeFTaskRef(FileLine* fl, const string& name, AstNode* pinsp)
+	:AstNode(fl)
+	, m_taskp(NULL), m_name(name), m_packagep(NULL) {
+	addNOp2p(pinsp);
+    }
     ASTNODE_BASE_FUNCS(NodeFTaskRef)
     virtual bool broken() const { return m_taskp && !m_taskp->brokeExists(); }
     virtual void cloneRelink() { if (m_taskp && m_taskp->clonep()) {

src/V3AstNodes.h

@@ -973,6 +973,8 @@ struct AstTaskRef : public AstNodeFTaskRef {
     // A reference to a task
     AstTaskRef(FileLine* fl, AstParseRef* namep, AstNode* pinsp)
 	:AstNodeFTaskRef(fl, namep, pinsp) {}
+    AstTaskRef(FileLine* fl, const string& name, AstNode* pinsp)
+	:AstNodeFTaskRef(fl, name, pinsp) {}
     ASTNODE_NODE_FUNCS(TaskRef, TASKREF)
 };
 
@@ -980,6 +982,8 @@ struct AstFuncRef : public AstNodeFTaskRef {
     // A reference to a function
     AstFuncRef(FileLine* fl, AstParseRef* namep, AstNode* pinsp)
 	:AstNodeFTaskRef(fl, namep, pinsp) {}
+    AstFuncRef(FileLine* fl, const string& name, AstNode* pinsp)
+	:AstNodeFTaskRef(fl, name, pinsp) {}
     ASTNODE_NODE_FUNCS(FuncRef, FUNCREF)
 };
 

src/V3Link.cpp

@@ -439,6 +439,14 @@ private:
 	}
 	nodep->iterateChildren(*this);
     }
+    virtual void visit(AstBasicDType* nodep, AstNUser*) {
+	if (m_idState==ID_RESOLVE && nodep->keyword()==AstBasicDTypeKwd::STRING) {
+	    if (!(m_ftaskp && m_ftaskp->dpiImport() && 0/*UNIMP*/)) {
+		nodep->v3error("Unsupported: SystemVerilog 'string' anywhere but DPI import __format");
+	    }
+	}
+	nodep->iterateChildren(*this);
+    }
 
     virtual void visit(AstCell* nodep, AstNUser*) {
 	// Cell: Resolve its filename.  If necessary, parse it.

src/V3ParseImp.h

@@ -128,8 +128,10 @@ public:
 	}
     }
     void reinsert(AstNode* nodep, V3SymTable* parentp=NULL) {
+	reinsert(nodep, parentp, nodep->name());
+    }
+    void reinsert(AstNode* nodep, V3SymTable* parentp, string name) {
 	if (!parentp) parentp = symCurrentp();
-	string name = nodep->name();
 	if (name == "") {  // New name with space in name so can't collide with users
 	    name = string(" anon") + nodep->type().ascii() + cvtToStr(++s_anonNum);
 	}

src/verilog.l

@@ -48,8 +48,8 @@ extern void yyerrorf(const char* format, ...);
 #define FL { yylval.fl = CRELINE(); }
 
 #define RETURN_BBOX_SYS_OR_MSG(msg,yytext) {	\
-	if (v3Global.opt.bboxSys()) return yD_aIGNORE; \
+	if (!v3Global.opt.bboxSys()) yyerrorf(msg,yytext); \
-	else yyerrorf(msg,yytext); }
+	return yaD_IGNORE; }
 
 void V3ParseImp::ppline (const char* textp) {
     // Handle `line directive
@@ -388,6 +388,7 @@ escid	\\[^ \t\f\r\n]+
   "pure"		{ FL; return yPURE; }
   "shortint"		{ FL; return ySHORTINT; }
   "static"		{ FL; return ySTATIC; }
+  "string"		{ FL; return ySTRING; }
   "timeprecision"	{ FL; return yTIMEPRECISION; }
   "timeunit"		{ FL; return yTIMEUNIT; }
   "typedef"		{ FL; return yTYPEDEF; }
@@ -443,7 +444,6 @@ escid	\\[^ \t\f\r\n]+
   "return"		{ yyerrorf("Unsupported: SystemVerilog 2005 reserved word not implemented: %s",yytext); }
   "shortreal"		{ yyerrorf("Unsupported: SystemVerilog 2005 reserved word not implemented: %s",yytext); }
   "solve"		{ yyerrorf("Unsupported: SystemVerilog 2005 reserved word not implemented: %s",yytext); }
-  "string"		{ yyerrorf("Unsupported: SystemVerilog 2005 reserved word not implemented: %s",yytext); }
   "struct"		{ yyerrorf("Unsupported: SystemVerilog 2005 reserved word not implemented: %s",yytext); }
   "super"		{ yyerrorf("Unsupported: SystemVerilog 2005 reserved word not implemented: %s",yytext); }
   "tagged"		{ yyerrorf("Unsupported: SystemVerilog 2005 reserved word not implemented: %s",yytext); }
@@ -473,7 +473,13 @@ escid	\\[^ \t\f\r\n]+
 
   /* Default PLI rule */
 <V95,V01,V05,S05,PSL>{
-  "$"[a-zA-Z_$][a-zA-Z0-9_$]*	{ FL; RETURN_BBOX_SYS_OR_MSG("Unsupported or unknown PLI call: %s",yytext); }
+  "$"[a-zA-Z_$][a-zA-Z0-9_$]*	{ string str (yytext,yyleng);
+				  yylval.strp = PARSEP->newString(AstNode::encodeName(str));
+				  // Lookup unencoded name including the $, to avoid hitting normal signals
+				  if (SYMP->symCurrentp()->findIdUpward(str)) {
+				      FL; return yaD_DPI;
+				  } else { FL; RETURN_BBOX_SYS_OR_MSG("Unsupported or unknown PLI call: %s",yytext); }
+				}
 }
 
   /************************************************************************/

src/verilog.y

@@ -132,7 +132,9 @@ public:
     }
     string   deQuote(FileLine* fileline, string text);
     void checkDpiVer(FileLine* fileline, const string& str) {
-	if (str != "DPI-C") { fileline->v3error("Unsupported DPI type '"<<str<<"': Use 'DPI-C'"); }
+	if (str != "DPI-C" && !v3Global.opt.bboxSys()) {
+	    fileline->v3error("Unsupported DPI type '"<<str<<"': Use 'DPI-C'");
+	}
     }
 };
 
@@ -203,6 +205,9 @@ class AstSenTree;
 %token<strp>		yaSCCTOR	"`systemc_implementation BLOCK"
 %token<strp>		yaSCDTOR	"`systemc_imp_header BLOCK"
 
+%token<strp>		yaD_IGNORE	"${ignored-bbox-sys}"
+%token<strp>		yaD_DPI		"${dpi-sys}"
+
 // <fl> is the fileline, abbreviated to shorten "$<fl>1" references
 %token<fl>		'!'
 %token<fl>		'#'
@@ -318,6 +323,7 @@ class AstSenTree;
 %token<fl>		ySPECIFY	"specify"
 %token<fl>		ySPECPARAM	"specparam"
 %token<fl>		ySTATIC		"static"
+%token<fl>		ySTRING		"string"
 %token<fl>		ySUPPLY0	"supply0"
 %token<fl>		ySUPPLY1	"supply1"
 %token<fl>		yTABLE		"table"
@@ -375,7 +381,6 @@ class AstSenTree;
 %token<fl>		yD_VALUEPLUSARGS "$value$plusargs"
 %token<fl>		yD_WARNING	"$warning"
 %token<fl>		yD_WRITE	"$write"
-%token<fl>		yD_aIGNORE	"${ignored-bbox-sys}"
 
 %token<fl>		yPSL		"psl"
 %token<fl>		yPSL_ASSERT	"PSL assert"
@@ -1053,7 +1058,7 @@ data_typeNoRef<dtypep>:		// ==IEEE: data_type, excluding class_type etc referenc
 	//UNSUP	yUNION taggedE packedSigningE '{' struct_union_memberList '}' packed_dimensionListE
 	//UNSUP		{ UNSUP }
 	//UNSUP	enumDecl				{ UNSUP }
-	//UNSUP	ySTRING					{ UNSUP }
+	|	ySTRING					{ $$ = new AstBasicDType($1,AstBasicDTypeKwd::STRING); }
 	|	yCHANDLE				{ $$ = new AstBasicDType($1,AstBasicDTypeKwd::CHANDLE); }
 	//UNSUP	yEVENT					{ UNSUP }
 	//UNSUP	yVIRTUAL__INTERFACE yINTERFACE id/*interface*/	{ UNSUP }
@@ -1922,8 +1927,11 @@ function_subroutine_callNoMethod<nodep>:	// IEEE: function_subroutine_call (as f
 
 system_t_call<nodep>:		// IEEE: system_tf_call (as task)
 	//
-		yD_aIGNORE  '(' ')'			{ $$ = NULL; }
+		yaD_IGNORE  '(' ')'			{ $$ = NULL; }
-	|	yD_aIGNORE  '(' exprList ')'		{ $$ = NULL; }
+	|	yaD_IGNORE  '(' exprList ')'		{ $$ = NULL; }
+	//
+	|	yaD_DPI '(' ')'				{ $$ = new AstTaskRef($2,*$1,NULL); }
+	|	yaD_DPI '(' exprList ')'		{ $$ = new AstTaskRef($2,*$1,$3); }
 	//
 	|	yD_C '(' cStrList ')'			{ $$ = (v3Global.opt.ignc() ? NULL : new AstUCStmt($1,$3)); }
 	|	yD_FCLOSE '(' idClassSel ')'		{ $$ = new AstFClose($1, $3); }
@@ -1962,8 +1970,11 @@ system_t_call<nodep>:		// IEEE: system_tf_call (as task)
 	;
 
 system_f_call<nodep>:		// IEEE: system_tf_call (as func)
-		yD_aIGNORE '(' ')'			{ $$ = new AstConst($1,V3Number($1,"'b0")); } // Unsized 0
+		yaD_IGNORE '(' ')'			{ $$ = new AstConst($2,V3Number($2,"'b0")); } // Unsized 0
-	|	yD_aIGNORE '(' exprList ')'		{ $$ = new AstConst($1,V3Number($1,"'b0")); } // Unsized 0
+	|	yaD_IGNORE '(' exprList ')'		{ $$ = new AstConst($2,V3Number($2,"'b0")); } // Unsized 0
+	//
+	|	yaD_DPI '(' ')'				{ $$ = new AstFuncRef($2,*$1,NULL); }
+	|	yaD_DPI '(' exprList ')'		{ $$ = new AstFuncRef($2,*$1,$3); }
 	//
 	|	yD_BITS '(' expr ')'			{ $$ = new AstAttrOf($1,AstAttrType::BITS,$3); }
 	|	yD_C '(' cStrList ')'			{ $$ = (v3Global.opt.ignc() ? NULL : new AstUCFunc($1,$3)); }
@@ -2154,10 +2165,14 @@ parenE:
 dpi_import_export<nodep>:	// ==IEEE: dpi_import_export
 		yIMPORT yaSTRING dpi_tf_import_propertyE dpi_importLabelE function_prototype ';'
 			{ $$ = $5; if (*$4!="") $5->cname(*$4); $5->dpiContext($3==iprop_CONTEXT); $5->pure($3==iprop_PURE);
-			  $5->dpiImport(true); GRAMMARP->checkDpiVer($1,*$2); v3Global.dpi(true); }
+			  $5->dpiImport(true); GRAMMARP->checkDpiVer($1,*$2); v3Global.dpi(true);
+			  if ($$->prettyName()[0]=='$') SYMP->reinsert($$,NULL,$$->prettyName());  // For $SysTF overriding
+			  SYMP->reinsert($$); }
 	|	yIMPORT yaSTRING dpi_tf_import_propertyE dpi_importLabelE task_prototype ';'
 			{ $$ = $5; if (*$4!="") $5->cname(*$4); $5->dpiContext($3==iprop_CONTEXT); $5->pure($3==iprop_PURE);
-			  $5->dpiImport(true); $5->dpiTask(true); GRAMMARP->checkDpiVer($1,*$2); v3Global.dpi(true); }
+			  $5->dpiImport(true); $5->dpiTask(true); GRAMMARP->checkDpiVer($1,*$2); v3Global.dpi(true);
+			  if ($$->prettyName()[0]=='$') SYMP->reinsert($$,NULL,$$->prettyName());  // For $SysTF overriding
+			  SYMP->reinsert($$); }
 	|	yEXPORT yaSTRING dpi_importLabelE yFUNCTION idAny ';'	{ $$ = new AstDpiExport($1,*$5,*$3);
 			  GRAMMARP->checkDpiVer($1,*$2); v3Global.dpi(true); }
 	|	yEXPORT yaSTRING dpi_importLabelE yTASK     idAny ';'	{ $$ = new AstDpiExport($1,*$5,*$3);

test_regress/t/t_dpi_sys.pl

@@ -0,0 +1,19 @@
+#!/usr/bin/perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2003 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.
+
+compile (
+    	 v_flags2 => ["t/t_dpi_sys_c.cpp"],
+	 );
+
+execute (
+	 check_finished=>1,
+     );
+
+ok(1);
+1;

test_regress/t/t_dpi_sys.v

@@ -0,0 +1,27 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// Copyright 2009 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.
+
+module t ();
+
+   import "DPI-C" dpii_sys_task = function void \$dpii_sys (integer i);
+   import "DPI-C" dpii_sys_func = function int \$dpii_func (integer i);
+
+`ifndef verilator
+   `error "Only Verilator supports PLI-ish DPI calls."
+`endif
+
+   initial begin
+      $dpii_sys(1);
+      if ($dpii_func(2) != 3) $stop;
+      $dpii_sys(10);
+      if ($dpii_func(2) != 12) $stop;
+
+      $write("*-* All Finished *-*\n");
+      $finish;
+   end
+
+endmodule

test_regress/t/t_dpi_sys_c.cpp

@@ -0,0 +1,49 @@
+// -*- C++ -*-
+//*************************************************************************
+//
+// Copyright 2009-2009 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.
+//
+// Verilator is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+//*************************************************************************
+
+#include <stdio.h>
+#include <svdpi.h>
+
+//======================================================================
+
+#if defined(VERILATOR)
+# include "Vt_dpi_sys__Dpi.h"
+#elif defined(VCS)
+# include "../vc_hdrs.h"
+#elif defined(CADENCE)
+# define NEED_EXTERNS
+#else
+# error "Unknown simulator for DPI test"
+#endif
+
+#ifdef NEED_EXTERNS
+extern "C" {
+
+    extern void dpii_sys_task (int i);
+    extern int dpii_sys_func (int i);
+
+}
+#endif
+
+//======================================================================
+
+static int hidden = 0;
+
+void dpii_sys_task(int i) {
+    hidden = i;
+}
+int dpii_sys_func(int i) {
+    return i + hidden;
+}