xml_parsert: construct with message handler

This both avoids an object of static lifetime as well as it fixes the
(transitive) use of the deprecated messaget() constructor.

Author: tautschnig

src/xmllang/parser.y

@@ -3,10 +3,10 @@
 
 #include "xml_parser.h"
 
-int yyxmllex();
+int yyxmllex(xml_parsert &xml_parser);
 extern char *yyxmltext;
 
-int yyxmlerror(const std::string &error)
+int yyxmlerror(xml_parsert &xml_parser, const std::string &error)
 {
   xml_parser.parse_error(error, yyxmltext);
   return 0;
@@ -26,6 +26,9 @@ int yyxmlerror(const std::string &error)
 #endif
 %}
 
+%parse-param {xml_parsert &xml_parser}
+%lex-param {xml_parsert &xml_parser}
+
 %union {char *s;}
 
 %token STARTXMLDECL

src/xmllang/scanner.l

@@ -19,7 +19,7 @@
 #include "xml_parser.h"
 #include "xml_y.tab.h"
 
-#define PARSER xml_parser
+#define PARSER (*xml_parser)
 
 //static int keep;  /* To store start condition */
 
@@ -65,6 +65,22 @@ string     \"([^"&]|{esc})*\"|\'([^'&]|{esc})*\'
 %s PI
 %s DTD
 
+%{
+static xml_parsert *xml_parser;
+
+int yyxmllex(void);
+
+int yyxmllex(xml_parsert &_xml_parser)
+{
+  // our scanner is not reentrant
+  PRECONDITION(!xml_parser);
+  xml_parser = &_xml_parser;
+  int result = yyxmllex();
+  xml_parser = nullptr;
+  return result;
+}
+%}
+
 %%
 
 <INITIAL,PI>{ws}  {/* skip */}
@@ -87,7 +103,7 @@ string     \"([^"&]|{esc})*\"|\'([^'&]|{esc})*\'
 <DTD>.            {/* skip */}
 <DTD>\]{close}    {BEGIN(INITIAL); /* skip */}
 
-.                 { yyxmlerror("unexpected character"); }
+.                 { yyxmlerror(*xml_parser, "unexpected character"); }
 {nl}              {/* skip, must be an extra one at EOF */;}
 
 %%

src/xmllang/xml_parser.cpp

@@ -10,7 +10,12 @@ Author: Daniel Kroening, kroening@kroening.com
 
 #include <fstream>
 
-xml_parsert xml_parser;
+int yyxmlparse(xml_parsert &);
+
+bool xml_parsert::parse()
+{
+  return yyxmlparse(*this) != 0;
+}
 
 // 'do it all' function
 bool parse_xml(
@@ -19,12 +24,12 @@ bool parse_xml(
   message_handlert &message_handler,
   xmlt &dest)
 {
-  xml_parser.clear();
+  xml_parsert xml_parser{message_handler};
+
   xml_parser.set_file(filename);
   xml_parser.in=&in;
-  xml_parser.log.set_message_handler(message_handler);
 
-  bool result=yyxmlparse()!=0;
+  bool result = xml_parser.parse();
 
   // save result
   xml_parser.parse_tree.element.swap(dest);

src/xmllang/xml_parser.h

@@ -14,11 +14,15 @@ Author: Daniel Kroening, kroening@kroening.com
 
 #include "xml_parse_tree.h"
 
-int yyxmlparse();
-
 class xml_parsert:public parsert
 {
 public:
+  explicit xml_parsert(message_handlert &message_handler)
+    : parsert(message_handler)
+  {
+    stack.push_back(&parse_tree.element);
+  }
+
   xml_parse_treet parse_tree;
 
   std::list<xmlt *> stack;
@@ -28,18 +32,15 @@ class xml_parsert:public parsert
     return *stack.back();
   }
 
-  virtual bool parse()
-  {
-    return yyxmlparse()!=0;
-  }
+  bool parse() override;
 
   void new_level()
   {
     current().elements.push_back(xmlt());
     stack.push_back(&current().elements.back());
   }
 
-  virtual void clear()
+  void clear() override
   {
     parse_tree.clear();
     // set up stack
@@ -48,9 +49,7 @@ class xml_parsert:public parsert
   }
 };
 
-extern xml_parsert xml_parser;
-
-int yyxmlerror(const std::string &error);
+int yyxmlerror(xml_parsert &xml_parser, const std::string &error);
 
 // 'do it all' functions
 bool parse_xml(