Handle packed unions properly during elaboration.

This also gets r-value use of packed unions correct.

elab_sig.cc

@@ -38,7 +38,6 @@
 # include  "netmisc.h"
 # include  "netclass.h"
 # include  "netenum.h"
-# include  "netstruct.h"
 # include  "netvector.h"
 # include  "netdarray.h"
 # include  "netparray.h"
@@ -873,47 +872,6 @@ static netclass_t* locate_class_type(Design*, NetScope*scope,
       return use_class;
 }
 
-netstruct_t* struct_type_t::elaborate_type(Design*des, NetScope*scope) const
-{
-      netstruct_t*res = new netstruct_t;
-
-      res->packed(packed_flag);
-
-      if (union_flag)
-	    res->union_flag(true);
-
-      for (list<struct_member_t*>::iterator cur = members->begin()
-		 ; cur != members->end() ; ++ cur) {
-
-	    vector<netrange_t>packed_dimensions;
-
-	    struct_member_t*curp = *cur;
-	    vector_type_t*vecp = dynamic_cast<vector_type_t*> (curp->type.get());
-	    if (vecp && vecp->pdims.get() && ! vecp->pdims->empty()) {
-		  bool bad_range;
-		  bad_range = evaluate_ranges(des, scope, packed_dimensions, *vecp->pdims);
-		  ivl_assert(*curp, !bad_range);
-	    } else {
-		  packed_dimensions.push_back(netrange_t(0,0));
-	    }
-
-	    netvector_t*mem_vec = new netvector_t(packed_dimensions,
-						  curp->type->figure_packed_base_type());
-
-	    for (list<decl_assignment_t*>::iterator name = curp->names->begin()
-		       ; name != curp->names->end() ;  ++ name) {
-		  decl_assignment_t*namep = *name;
-
-		  netstruct_t::member_t memb;
-		  memb.name = namep->name;
-		  memb.net_type = mem_vec;
-		  res->append_member(memb);
-	    }
-      }
-
-      return res;
-}
-
 static ivl_type_s*elaborate_type(Design*des, NetScope*scope,
 				 data_type_t*pform_type)
 {

elab_type.cc

@@ -22,6 +22,7 @@
 # include  "netclass.h"
 # include  "netdarray.h"
 # include  "netscalar.h"
+# include  "netstruct.h"
 # include  "netvector.h"
 # include  "netmisc.h"
 # include  <typeinfo>
@@ -130,6 +131,39 @@ ivl_type_s* string_type_t::elaborate_type(Design*, NetScope*) const
       return &netstring_t::type_string;
 }
 
+netstruct_t* struct_type_t::elaborate_type(Design*des, NetScope*scope) const
+{
+      netstruct_t*res = new netstruct_t;
+
+      res->packed(packed_flag);
+
+      if (union_flag)
+	    res->union_flag(true);
+
+      for (list<struct_member_t*>::iterator cur = members->begin()
+		 ; cur != members->end() ; ++ cur) {
+
+	      // Elaborate the type of the member.
+	    struct_member_t*curp = *cur;
+	    ivl_type_t mem_vec = curp->type->elaborate_type(des, scope);
+
+	      // There may be several names that are the same type:
+	      //   <data_type> name1, name2, ...;
+	      // Process all the member, and give them a type.
+	    for (list<decl_assignment_t*>::iterator name = curp->names->begin()
+		       ; name != curp->names->end() ;  ++ name) {
+		  decl_assignment_t*namep = *name;
+
+		  netstruct_t::member_t memb;
+		  memb.name = namep->name;
+		  memb.net_type = mem_vec;
+		  res->append_member(des, memb);
+	    }
+      }
+
+      return res;
+}
+
 ivl_type_s* uarray_type_t::elaborate_type(Design*des, NetScope*scope) const
 {
 

netstruct.cc

@@ -17,10 +17,13 @@
  *    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */
 
+# include  "netlist.h"
 # include  "netstruct.h"
 # include  "netvector.h"
 # include  <iostream>
 
+# include  "ivl_assert.h"
+
 using namespace std;
 
 netstruct_t::netstruct_t()
@@ -34,17 +37,43 @@ netstruct_t::~netstruct_t()
 
 void netstruct_t::union_flag(bool flag)
 {
+	// This MUST be called before any members are pushed into the
+	// definition. This is because the append relies on this flag
+	// being accurate.
+      ivl_assert(*this, members_.empty());
       union_ = flag;
 }
 
 void netstruct_t::packed(bool flag)
 {
+      ivl_assert(*this, members_.empty());
       packed_ = flag;
 }
 
-void netstruct_t::append_member(const netstruct_t::member_t&val)
+void netstruct_t::append_member(Design*des, const netstruct_t::member_t&val)
 {
       members_.push_back(val);
+      if (packed_) {
+	    if (! members_.back().net_type->packed()) {
+		  cerr << get_fileline() << ": error: "
+		       << "Member " << members_.back().name
+		       << " of packed struct/union"
+		       << " must be packed." << endl;
+		  des->errors += 1;
+	    }
+      }
+      if (union_ && packed_ && members_.size() > 1) {
+	    unsigned long expect_wid = members_.front().net_type->packed_width();
+	    unsigned long got_wid = members_.back().net_type->packed_width();
+	    if (expect_wid != got_wid) {
+		  cerr << get_fileline() << ": error: "
+		       << "Member " << val.name
+		       << " of packed union"
+		       << " is " << got_wid
+		       << " bits, expecting " << expect_wid << " bits." << endl;
+		  des->errors += 1;
+	    }
+      }
 }
 
 const netstruct_t::member_t* netstruct_t::packed_member(perm_string name, unsigned long&off) const
@@ -55,7 +84,11 @@ const netstruct_t::member_t* netstruct_t::packed_member(perm_string name, unsign
 		  off = count_off;
 		  return &members_[idx-1];
 	    }
-	    count_off += members_[idx-1].net_type->packed_width();
+	      // If this is not a union, then the members are lined up
+	      // from LSB to MSB.  If this is a union, then all
+	      // members are at offset 0.
+	    if (!union_)
+		  count_off += members_[idx-1].net_type->packed_width();
       }
 
       return 0;
@@ -66,6 +99,13 @@ long netstruct_t::packed_width(void) const
       if (! packed_)
 	    return -1;
 
+	// If this is a packed union, then all the members are the
+	// same width, so it is sufficient to return the width of any
+	// single member.
+      if (union_)
+	    return members_.front().net_type->packed_width();
+
+	// The width of a packed struct is the sum of member widths.
       long res = 0;
       for (size_t idx = 0 ; idx < members_.size() ; idx += 1)
 	    res += members_[idx].net_type->packed_width();

netstruct.h

@@ -24,6 +24,8 @@
 # include  "ivl_target.h"
 # include  "nettypes.h"
 
+class Design;
+
 class netstruct_t : public LineInfo, public ivl_type_s {
 
     public:
@@ -49,7 +51,11 @@ class netstruct_t : public LineInfo, public ivl_type_s {
       void packed(bool flag);
       bool packed(void) const;
 
-      void append_member(const member_t&);
+	// Append a new member to the struct/union. This must be done
+	// after the union_flag and packed settings are set. This
+	// function does error checking, and the "des" argument is
+	// only present so that it can set error flags.
+      void append_member(Design*des, const member_t&);
 
 	// Given the name of a member, return a pointer to the member
 	// description, and set the off value to be the offset into