Parse for declarations, implement for_step statements.

for-statement declarations still generate a "sorry" message, but
the for_step statements work in general now.

Statement.cc

@@ -276,9 +276,8 @@ PForever::~PForever()
 }
 
 PForStatement::PForStatement(PExpr*n1, PExpr*e1, PExpr*cond,
-			     PExpr*n2, PExpr*e2, Statement*st)
+			     Statement*step, Statement*st)
-: name1_(n1), expr1_(e1), cond_(cond), name2_(n2), expr2_(e2),
+: name1_(n1), expr1_(e1), cond_(cond), step_(step), statement_(st)
-  statement_(st)
 {
 }
 

Statement.h

@@ -403,7 +403,7 @@ class PForStatement  : public Statement {
 
     public:
       PForStatement(PExpr*n1, PExpr*e1, PExpr*cond,
-		    PExpr*n2, PExpr*e2, Statement*st);
+		    Statement*step, Statement*body);
       ~PForStatement();
 
       virtual NetProc* elaborate(Design*des, NetScope*scope) const;
@@ -417,8 +417,7 @@ class PForStatement  : public Statement {
 
       PExpr*cond_;
 
-      PExpr* name2_;
+      Statement*step_;
-      PExpr* expr2_;
 
       Statement*statement_;
 };

elaborate.cc

@@ -3780,8 +3780,6 @@ NetProc* PForStatement::elaborate(Design*des, NetScope*scope) const
 
       const PEIdent*id1 = dynamic_cast<const PEIdent*>(name1_);
       assert(id1);
-      const PEIdent*id2 = dynamic_cast<const PEIdent*>(name2_);
-      assert(id2);
 
       NetBlock*top = new NetBlock(NetBlock::SEQU, 0);
       top->set_line(*this);
@@ -3826,32 +3824,15 @@ NetProc* PForStatement::elaborate(Design*des, NetScope*scope) const
 	    body->append(tmp);
 
 
-	/* Elaborate the increment assignment statement at the end of
+	/* Now elaborate the for_step statement. I really should do
-	   the for loop. This is also a very specific assignment
+	   some error checking here to make sure the step statement
-	   statement. Put this into the "body" block. */
+	   really does step the variable. */
-      sig = des->find_signal(scope, id2->path());
-      if (sig == 0) {
-	    cerr << get_fileline() << ": error: Unable to find variable "
-		 << id2->path() << " in for-loop increment expression." << endl;
-	    des->errors += 1;
-	    return body;
-      }
-
-      assert(sig);
-      lv = new NetAssign_(sig);
-
-	/* Make the r-value of the increment assignment, and size it
-	   properly. Then use it to build the assignment statement. */
-      etmp = elaborate_rval_expr(des, scope, lv->expr_type(), lv->lwidth(),
-                                 expr2_);
-
       if (debug_elaborate) {
-	    cerr << get_fileline() << ": debug: FOR increment assign: "
+	    cerr << get_fileline() << ": debug: Elaborate for_step statement "
 		 << sig->name() << " = " << *etmp << endl;
       }
 
-      NetAssign*step = new NetAssign(lv, etmp);
+      NetProc*step = step_->elaborate(des, scope);
-      step->set_line(*this);
 
       body->append(step);
 

parse.y

@@ -524,6 +524,7 @@ static void current_task_set_statement(vector<Statement*>*s)
 %type <event_expr> event_expression
 %type <event_statement> event_control
 %type <statement> statement statement_or_null compressed_statement
+%type <statement> loop_statement for_step
 %type <statement_list> statement_list statement_or_null_list
 %type <statement_list> statement_list_or_null
 
@@ -660,6 +661,19 @@ data_type /* IEEE1800-2005: A.2.2.1 */
 
 endnew_opt : ':' K_new | ;
 
+for_step /* IEEE1800-2005: A.6.8 */
+  : lpvalue '=' expression
+      { PAssign*tmp = new PAssign($1,$3);
+	FILE_NAME(tmp, @1);
+	$$ = tmp;
+      }
+  | inc_or_dec_expression
+      { $$ = pform_compressed_assign_from_inc_dec(@1, $1); }
+  | compressed_statement
+      { $$ = $1; }
+  ;
+
+
 implicit_class_handle /* IEEE1800-2005: A.8.4 */
   : K_this
   | K_super
@@ -694,6 +708,66 @@ inc_or_dec_expression /* IEEE1800-2005: A.4.3 */
       }
   ;
 
+  /* Loop statements are kinds of statements. */
+
+loop_statement /* IEEE1800-2005: A.6.8 */
+  : K_for '(' lpvalue '=' expression ';' expression ';' for_step ')'
+    statement_or_null
+      { PForStatement*tmp = new PForStatement($3, $5, $7, $9, $11);
+	FILE_NAME(tmp, @1);
+	$$ = tmp;
+      }
+
+  | K_for '(' data_type IDENTIFIER '=' expression ';' expression ';' for_step ')'
+    statement_or_null
+      { $$ = 0;
+	yyerror(@3, "sorry: for_variable_declaration not supported");
+      }
+
+  | K_forever statement_or_null
+      { PForever*tmp = new PForever($2);
+	FILE_NAME(tmp, @1);
+	$$ = tmp;
+      }
+
+  | K_repeat '(' expression ')' statement_or_null
+      { PRepeat*tmp = new PRepeat($3, $5);
+	FILE_NAME(tmp, @1);
+	$$ = tmp;
+      }
+
+  | K_while '(' expression ')' statement_or_null
+      { PWhile*tmp = new PWhile($3, $5);
+	FILE_NAME(tmp, @1);
+	$$ = tmp;
+      }
+
+  /* Error forms for loop statements. */
+
+  | K_for '(' lpvalue '=' expression ';' expression ';' error ')'
+    statement_or_null
+      { $$ = 0;
+	yyerror(@1, "error: Error in for loop step assignment.");
+      }
+
+  | K_for '(' lpvalue '=' expression ';' error ';' for_step ')'
+    statement_or_null
+      { $$ = 0;
+	yyerror(@1, "error: Error in for loop condition expression.");
+      }
+
+  | K_for '(' error ')' statement_or_null
+      { $$ = 0;
+	yyerror(@1, "error: Incomprehensible for loop.");
+      }
+
+  | K_while '(' error ')' statement_or_null
+      { $$ = 0;
+	yyerror(@1, "error: Error in while loop condition.");
+      }
+
+  ;
+
 number  : BASED_NUMBER
 	     { $$ = $1; based_size = 0;}
         | DEC_NUMBER
@@ -710,6 +784,16 @@ real_or_realtime
 	| K_realtime
 	;
 
+  /* Many places where statements are allowed can actually take a
+     statement or a null statement marked with a naked semi-colon. */
+
+statement_or_null /* IEEE1800-2005: A.6.4 */
+  : statement
+      { $$ = $1; }
+  | ';'
+      { $$ = 0; }
+  ;
+
   /* The task declaration rule matches the task declaration
      header, then pushes the function scope. This causes the
      definitions in the task_body to take on the scope of the task
@@ -5079,16 +5163,9 @@ statement /* This is roughly statement_item in the LRM */
 		  delete $2;
 		  $$ = tmp;
 		}
-	| K_forever statement
+
-		{ PForever*tmp = new PForever($2);
+  | loop_statement { $$ = $1; }
-		  FILE_NAME(tmp, @1);
+
-		  $$ = tmp;
-		}
-	| K_repeat '(' expression ')' statement
-		{ PRepeat*tmp = new PRepeat($3, $5);
-		  FILE_NAME(tmp, @1);
-		  $$ = tmp;
-		}
 	| K_case '(' expression ')' case_items K_endcase
 		{ PCase*tmp = new PCase(NetCase::EQ, $3, $5);
 		  FILE_NAME(tmp, @1);
@@ -5128,36 +5205,6 @@ statement /* This is roughly statement_item in the LRM */
 		{ yyerror(@1, "error: Malformed conditional expression.");
 		  $$ = $5;
 		}
-	| K_for '(' lpvalue '=' expression ';' expression ';'
-	  lpvalue '=' expression ')' statement
-		{ PForStatement*tmp = new PForStatement($3, $5, $7, $9, $11, $13);
-		  FILE_NAME(tmp, @1);
-		  $$ = tmp;
-		}
-	| K_for '(' lpvalue '=' expression ';' expression ';'
-	  error ')' statement
-		{ $$ = 0;
-		  yyerror(@1, "error: Error in for loop step assignment.");
-		}
-	| K_for '(' lpvalue '=' expression ';' error ';'
-	  lpvalue '=' expression ')' statement
-		{ $$ = 0;
-		  yyerror(@1, "error: Error in for loop condition expression.");
-		}
-	| K_for '(' error ')' statement
-		{ $$ = 0;
-		  yyerror(@1, "error: Incomprehensible for loop.");
-		}
-	| K_while '(' expression ')' statement
-		{ PWhile*tmp = new PWhile($3, $5);
-		  FILE_NAME(tmp, @1);
-		  $$ = tmp;
-		}
-	| K_while '(' error ')' statement
-		{ $$ = 0;
-		  yyerror(@1, "error: Error in while loop condition.");
-		}
-
   /* SytemVerilog adds the compressed_statement */
 
   | compressed_statement ';'
@@ -5406,13 +5453,6 @@ statement_list
       }
   ;
 
-statement_or_null
-  : statement
-      { $$ = $1; }
-  | ';'
-      { $$ = 0; }
-  ;
-
 statement_or_null_list
   : statement_or_null_list statement_or_null
       { vector<Statement*>*tmp = $1;

pform_dump.cc

@@ -774,8 +774,8 @@ void PForever::dump(ostream&out, unsigned ind) const
 void PForStatement::dump(ostream&out, unsigned ind) const
 {
       out << setw(ind) << "" << "for (" << *name1_ << " = " << *expr1_
-	  << "; " << *cond_ << "; " << *name2_ << " = " << *expr2_ <<
+	  << "; " << *cond_ << "; <for_step>)" << endl;
-	    ")" << endl;
+      step_->dump(out, ind+6);
       statement_->dump(out, ind+3);
 }