[BUGFIX] Fix crash in parser.

[ginac.git] / ginac / parser / parser.cpp

diff --git a/ginac/parser/parser.cpp b/ginac/parser/parser.cpp
index 0ee682ab7f108bc60a6a47d1141b65208a461abb..a7288c32a6b3e614c6b06adc910a5fff2fcb9e99 100644 (file)
--- a/ginac/parser/parser.cpp
+++ b/ginac/parser/parser.cpp
@@ -1,13 +1,51 @@
-#include <stdexcept>
-#include <sstream>
-#include "parser.hpp"
-#include "lexer.hpp"
-#include "debug.hpp"
+/** @file parser.cpp
+ *
+ *  Implementation of GiNaC's parser. */
+
+/*
+ *  GiNaC Copyright (C) 1999-2024 Johannes Gutenberg University Mainz, Germany
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include "parser.h"
+#include "lst.h"
+#include "lexer.h"
+#include "debug.h"
 #include "mul.h"
 #include "constant.h"
+#include "function.h"
+#include "operators.h"
+
+#include <cstdint> // for uintptr_t
+#include <sstream>
+#include <stdexcept>
+
+namespace GiNaC {
 
-namespace GiNaC 
+ex reader_func::operator()(const exvector& args) const
 {
+       switch (type) {
+       case FUNCTION_PTR:
+               return func(args);
+       case GINAC_FUNCTION:
+               return function(serial, args);
+       default:
+               abort();
+       }
+}
 
 /// identifier_expr:  identifier |  identifier '(' expression* ')'
 ex parser::parse_identifier_expr()
@@ -37,14 +75,14 @@ ex parser::parse_identifier_expr()
        }
        // Eat the ')'.
        get_next_tok();
-       prototype the_prototype = make_pair(name, args.size());
-       prototype_table::const_iterator reader = funcs.find(the_prototype);
+       auto reader = funcs.find({name, args.size()});
        if (reader == funcs.end()) {
                Parse_error_("no function \"" << name << "\" with " <<
                             args.size() << " arguments");
        }
-       ex ret = reader->second(args);
-       return ret;
+       // reader->second might be a pointer to a C++ function or a specially
+       // crafted serial of a GiNaC::function.
+       return reader->second(args);
 }
 
 /// paren_expr:  '(' expression ')'
@@ -59,22 +97,32 @@ ex parser::parse_paren_expr()
        return e;
 }
 
-extern numeric* _num_1_p;
-
-/// unary_expr: [+-] expression
-ex parser::parse_unary_expr(const int s)
+/// lst_expr:  '{' expression { ',' expression } '}'
+ex parser::parse_lst_expr()
 {
-       // consume '-' (or '+')
-       get_next_tok();
-       ex v = parse_expression();
-       switch (s) {
-               case '-':
-                       return (new mul(v, *_num_1_p))->setflag(status_flags::dynallocated);
-               case '+':
-                       return v;
-               default:
-                       Parse_error_("invalid unary operator \"" << char(s) << "\"");
+       get_next_tok();  // eat {.
+
+       lst list;
+       if (token != '}') {
+               while (true) {
+                       ex e = parse_expression(); // expression();
+                       list.append(e);
+
+                       if (token == '}') {
+                               break;
+                       }
+
+                       if (token != ',') {
+                               Parse_error("expected '}'");
+                       }
+
+                       get_next_tok();  // eat ','.
+               }
        }
+       // Eat the '}'.
+       get_next_tok();
+
+       return list;
 }
 
 /// primary: identifier_expr | number_expr | paren_expr | unary_expr 
@@ -87,10 +135,12 @@ ex parser::parse_primary()
                         return parse_number_expr();
                case '(': 
                         return parse_paren_expr();
+               case '{': 
+                        return parse_lst_expr();
                case '-':
-                        return parse_unary_expr('-');
+                        return -parse_unary_expr();
                case '+':
-                        return parse_unary_expr('+');
+                        return parse_unary_expr();
                case lexer::token_type::literal:
                         return parse_literal_expr();
                case lexer::token_type::eof:
@@ -118,6 +168,7 @@ ex parser::parse_number_expr()
 /// literal_expr: 'I' | 'Pi' | 'Euler' | 'Catalan'
 ex parser::parse_literal_expr()
 {
+       get_next_tok(); // consume the literal
        if (scanner->str == "I")
                return I;
        else if (scanner->str == "Pi")
@@ -134,6 +185,13 @@ ex parser::operator()(std::istream& input)
        scanner->switch_input(&input);
        get_next_tok();
        ex ret = parse_expression();
+       // parse_expression() stops if it encounters an unknown token.
+       // This is not a bug: since the parser is recursive, checking
+       // whether the next token is valid is responsibility of the caller.
+       // Hence make sure nothing is left in the stream:
+       if (token != lexer::token_type::eof)
+               Parse_error("expected EOF");
+
        return ret;
 }