Have scope auto-rename generate names that use the index numbers

In generate blocks such as for loops, there may be many generated
scopes that have the same generated name. But in these cases, there
is an index number in the hname that can be used. So do so.

(cherry picked from commit 81f54ec0cb)

HName.cc

@@ -40,7 +40,7 @@ hname_t::hname_t(perm_string text, int num)
       number_[0] = num;
 }
 
-hname_t::hname_t(perm_string text, vector<int>&nums)
+hname_t::hname_t(perm_string text, const vector<int>&nums)
 : name_(text), number_(nums)
 {
 }

HName.h

@@ -42,7 +42,7 @@ class hname_t {
       hname_t ();
       explicit hname_t (perm_string text);
       explicit hname_t (perm_string text, int num);
-      explicit hname_t (perm_string text, std::vector<int>&nums);
+      explicit hname_t (perm_string text, const std::vector<int>&nums);
       hname_t (const hname_t&that);
       ~hname_t();
 
@@ -56,12 +56,12 @@ class hname_t {
 
       size_t has_numbers() const;
       int peek_number(size_t idx) const;
+      const std::vector<int>&peek_numbers() const;
 
     private:
       perm_string name_;
-	// If the number is anything other than INT_MIN, then this is
-	// the numeric part of the name. Otherwise, it is not part of
-	// the name at all.
+	// If this vector has size, then the numbers all together make
+	// up part of the hierarchical name.
       std::vector<int> number_;
 
     private: // not implemented
@@ -82,6 +82,11 @@ inline int hname_t::peek_number(size_t idx) const
       return number_[idx];
 }
 
+inline const std::vector<int>& hname_t::peek_numbers(void) const
+{
+      return number_;
+}
+
 inline size_t hname_t::has_numbers() const
 {
       return number_.size();

elaborate.cc

@@ -5728,6 +5728,9 @@ bool PGenerate::elaborate(Design*des, NetScope*container) const
 		  "generate " << scheme_type
 		 << " elaborating in scope " << scope_path(container)
 		 << "." << endl;
+	    cerr << get_fileline() << ": PGenerate::elaborate: "
+		  "generate scope_name=" << scope_name
+		 << ", id_number=" << id_number << endl;
       }
 
 	// Handle the special case that this is a CASE scheme. In this
@@ -5762,6 +5765,7 @@ bool PGenerate::elaborate(Design*des, NetScope*container) const
 	      // scheme defined in the Verilog-2005 standard.
 	    const char*name = scope_name.str();
 	    if (name[0] == '$') {
+
 		  if (!scope->auto_name("genblk", '0', name + 4)) {
 			cerr << get_fileline() << ": warning: Couldn't build"
 			     << " unique name for unnamed generate block"

net_scope.cc

@@ -264,19 +264,20 @@ bool NetScope::auto_name(const char*prefix, char pad, const char* suffix)
       assert(self != up_->children_.end());
       assert(self->second == this);
 
-      char tmp[32];
-      int pad_pos = strlen(prefix);
-      int max_pos = sizeof(tmp) - strlen(suffix) - 1;
-      strncpy(tmp, prefix, sizeof(tmp));
-      tmp[31] = 0;
+	// This is to keep the pad attempts from being stuck in some
+	// sort of infinite loop. This should not be a practical
+	// limit, but an extreme one.
+      const size_t max_pad_attempts = 32 + strlen(prefix);
+
+      string use_prefix = prefix;
 
 	// Try a variety of potential new names. Make sure the new
 	// name is not in the parent scope. Keep looking until we are
 	// sure we have a unique name, or we run out of names to try.
-      while (pad_pos <= max_pos) {
+      while (use_prefix.size() <= max_pad_attempts) {
 	      // Try this name...
-	    strcat(tmp + pad_pos, suffix);
-	    hname_t new_name(lex_strings.make(tmp));
+	    string tmp = use_prefix + suffix;
+	    hname_t new_name(lex_strings.make(tmp.c_str()), name_.peek_numbers());
 	    if (!up_->child(new_name)) {
 		    // Ah, this name is unique. Rename myself, and
 		    // change my name in the parent scope.
@@ -285,7 +286,9 @@ bool NetScope::auto_name(const char*prefix, char pad, const char* suffix)
 		  up_->children_[name_] = this;
 		  return true;
 	    }
-	    tmp[pad_pos++] = pad;
+
+	      // Name collides, so try a different name.
+	    use_prefix = use_prefix + pad;
       }
       return false;
 }