Fix DPI import false BLKSEQ warnings.

Changes

@@ -15,6 +15,8 @@ indicates the contributor was also the author of the fix; Thanks!
 
 **** Fix DPI import output of 64 bits, bug398. [Mike Denio]
 
+**** Fix DPI import false BLKSEQ warnings.  [Alex Solomatnikov]
+
 **** Fix MSVC compile warning with trunc/round, bug394. [Amir Gonnen]
 
 **** Fix autoconf and Makefile warnings, bug396.  [Ruben Diez]

src/V3Task.cpp

@@ -408,6 +408,7 @@ private:
 		    AstAssign* assp = new AstAssign (pinp->fileline(),
 						     pinp,
 						     new AstVarRef(outvscp->fileline(), outvscp, false));
+		    assp->fileline()->modifyWarnOff(V3ErrorCode::BLKSEQ, true);  // Ok if in <= block
 		    // Put assignment BEHIND of all other statements
 		    beginp->addNext(assp);
 		}
@@ -418,6 +419,7 @@ private:
 		    AstAssign* assp = new AstAssign (pinp->fileline(),
 						     new AstVarRef(inVscp->fileline(), inVscp, true),
 						     pinp);
+		    assp->fileline()->modifyWarnOff(V3ErrorCode::BLKSEQ, true);  // Ok if in <= block
 		    // Put assignment in FRONT of all other statements
 		    if (AstNode* afterp = beginp->nextp()) {
 			afterp->unlinkFrBackWithNext();
@@ -507,6 +509,7 @@ private:
 		    AstAssign* assp = new AstAssign (pinp->fileline(),
 						     pinp,
 						     new AstVarRef(outvscp->fileline(), outvscp, false));
+		    assp->fileline()->modifyWarnOff(V3ErrorCode::BLKSEQ, true);  // Ok if in <= block
 		    // Put assignment BEHIND of all other statements
 		    beginp->addNext(assp);
 		}

test_regress/t/t_dpi_import.v

@@ -15,7 +15,11 @@
  `define NO_SHORTREAL
 `endif
 
-module t ();
+module t (/*AUTOARG*/
+   // Inputs
+   clk
+   );
+   input clk;
 
    // Allowed import return types:
    //         void, byte, shortint, int, longint, real, shortreal, chandle, and string
@@ -194,4 +198,10 @@ module t ();
       $finish;
    end
 
+   always @ (posedge clk) begin
+      i_b <= ~i_b;
+      // This once mis-threw a BLKSEQ warning
+      dpii_v_bit (i_b,o_b); if (o_b !== ~i_b) $stop;
+   end
+
 endmodule