Add file/line information to entities and ports

Include the compiler infrastructure to vhdlpp for collecting the
file and line information and attaching it to entities and ports.
Make the parser store the file name during parse.

Create a libmisc library where I can put source files that are
used by multiple programs within the source tree.

libmisc/StringHeap.h

@@ -0,0 +1,120 @@
+#ifndef __StringHeap_H
+#define __StringHeap_H
+/*
+ * Copyright (c) 2002-2009 Stephen Williams ([email protected])
+ *
+ *    This source code is free software; you can redistribute it
+ *    and/or modify it in source code form under the terms of the GNU
+ *    General Public License as published by the Free Software
+ *    Foundation; either version 2 of the License, or (at your option)
+ *    any later version.
+ *
+ *    This program 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.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program; if not, write to the Free Software
+ *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ */
+
+# include  <string>
+
+using namespace std;
+
+class perm_string {
+
+    public:
+      perm_string() : text_(0) { }
+      perm_string(const perm_string&that) : text_(that.text_) { }
+      ~perm_string() { }
+
+      perm_string& operator = (const perm_string&that)
+      { text_ = that.text_; return *this; }
+
+      const char*str() const { return text_; }
+      operator const char* () const { return str(); }
+
+	// This is an escape for making perm_string objects out of
+	// literals. For example, perm_string::literal("Label"); Please
+	// do *not* cheat and pass arbitrary const char* items here.
+      static perm_string literal(const char*t) { return perm_string(t); }
+
+    private:
+      friend class StringHeap;
+      friend class StringHeapLex;
+      perm_string(const char*t) : text_(t) { };
+
+    private:
+      const char*text_;
+};
+
+extern bool operator == (perm_string a, perm_string b);
+extern bool operator == (perm_string a, const char* b);
+extern bool operator != (perm_string a, perm_string b);
+extern bool operator != (perm_string a, const char* b);
+extern bool operator >  (perm_string a, perm_string b);
+extern bool operator <  (perm_string a, perm_string b);
+extern bool operator >= (perm_string a, perm_string b);
+extern bool operator <= (perm_string a, perm_string b);
+
+/*
+ * The string heap is a way to permanently allocate strings
+ * efficiently. They only take up the space of the string characters
+ * and the terminating nul, there is no malloc overhead.
+ */
+class StringHeap {
+
+    public:
+      StringHeap();
+      ~StringHeap();
+
+      const char*add(const char*);
+      perm_string make(const char*);
+
+    private:
+      enum { HEAPCELL = 0x10000 };
+
+      char*cell_base_;
+      unsigned cell_ptr_;
+      unsigned cell_count_;
+
+    private: // not implemented
+      StringHeap(const StringHeap&);
+      StringHeap& operator= (const StringHeap&);
+};
+
+/*
+ * A lexical string heap is a string heap that makes an effort to
+ * return the same pointer for identical strings. This saves further
+ * space by not allocating duplicate strings, so in a system with lots
+ * of identifiers, this can theoretically save more space.
+ */
+class StringHeapLex  : private StringHeap {
+
+    public:
+      StringHeapLex();
+      ~StringHeapLex();
+
+      const char*add(const char*);
+      perm_string make(const char*);
+      perm_string make(const string&);
+
+      unsigned add_count() const;
+      unsigned add_hit_count() const;
+      void cleanup();
+
+    private:
+      enum { HASH_SIZE = 4096 };
+      const char*hash_table_[HASH_SIZE];
+
+      unsigned add_count_;
+      unsigned hit_count_;
+
+    private: // not implemented
+      StringHeapLex(const StringHeapLex&);
+      StringHeapLex& operator= (const StringHeapLex&);
+};
+
+#endif