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. Both the
parser and lexer are now fully reentrant.

Author: tautschnig

Diff for: src/xmllang/parser.y

@@ -3,12 +3,12 @@
 
 #include "xml_parser.h"
 
-int yyxmllex();
-extern char *yyxmltext;
+int yyxmllex(void *);
+char *yyxmlget_text(void *);
 
-int yyxmlerror(const std::string &error)
+int yyxmlerror(xml_parsert &xml_parser, void *scanner, const std::string &error)
 {
-  xml_parser.parse_error(error, yyxmltext);
+  xml_parser.parse_error(error, yyxmlget_text(scanner));
   return 0;
 }
 
@@ -26,6 +26,10 @@ int yyxmlerror(const std::string &error)
 #endif
 %}
 
+%parse-param {xml_parsert &xml_parser}
+%parse-param {void *scanner}
+%lex-param {void *scanner}
+
 %union {char *s;}
 
 %token STARTXMLDECL

Diff for: src/xmllang/scanner.l

@@ -3,6 +3,9 @@
 %option noinput
 %option nounistd
 %option never-interactive
+%option noyywrap
+%option reentrant
+%option extra-type="xml_parsert *"
 
 %{
 
@@ -19,7 +22,7 @@
 #include "xml_parser.h"
 #include "xml_y.tab.h"
 
-#define PARSER xml_parser
+#define PARSER (*yyextra)
 
 //static int keep;  /* To store start condition */
 
@@ -87,9 +90,5 @@ string     \"([^"&]|{esc})*\"|\'([^'&]|{esc})*\'
 <DTD>.            {/* skip */}
 <DTD>\]{close}    {BEGIN(INITIAL); /* skip */}
 
-.                 { yyxmlerror("unexpected character"); }
+.                 { yyxmlerror(*yyextra, yyscanner, "unexpected character"); }
 {nl}              {/* skip, must be an extra one at EOF */;}
-
-%%
-
-int yywrap() { return 1; }

Diff for: src/xmllang/xml_parser.cpp

@@ -10,7 +10,18 @@ Author: Daniel Kroening, [email protected]
 
 #include <fstream>
 
-xml_parsert xml_parser;
+int yyxmllex_init_extra(xml_parsert *, void **);
+int yyxmllex_destroy(void *);
+int yyxmlparse(xml_parsert &, void *);
+
+bool xml_parsert::parse()
+{
+  void *scanner;
+  yyxmllex_init_extra(this, &scanner);
+  bool parse_fail = yyxmlparse(*this, scanner) != 0;
+  yyxmllex_destroy(scanner);
+  return parse_fail;
+}
 
 // 'do it all' function
 bool parse_xml(
@@ -19,12 +30,12 @@ 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);

Diff for: src/xmllang/xml_parser.h

@@ -14,11 +14,15 @@ Author: Daniel Kroening, [email protected]
 
 #include "xml_parse_tree.h"
 
-int yyxmlparse();
-
 class xml_parsert:public parsert
 {
 public:
+  explicit xml_parsert(message_handlert &message_handler)
+    : parsert(message_handler)
+  {
+    clear();
+  }
+
   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 &, void *, const std::string &);
 
 // 'do it all' functions
 bool parse_xml(