* Implementation of GiNaC's parser. */
/*
- * GiNaC Copyright (C) 1999-2010 Johannes Gutenberg University Mainz, Germany
+ * GiNaC Copyright (C) 1999-2011 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
#include "mul.h"
#include "constant.h"
#include "function.h"
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+#ifdef HAVE_STDINT_H
+#include <stdint.h> // for uintptr_t
+#endif
#include <sstream>
#include <stdexcept>
namespace GiNaC {
+// <KLUDGE>
+// Find out if ptr is a pointer to a function or a specially crafted integer.
+// It's possible to distinguish between these because functions are aligned.
+// Returns true if ptr is a pointer and false otherwise.
+static bool decode_serial(unsigned& serial, const reader_func ptr)
+{
+ uintptr_t u = (uintptr_t)(void *)ptr;
+ if (u & 1) {
+ u >>= 1;
+ serial = (unsigned)u;
+ return false;
+ }
+ return true;
+}
+
+// Figures out if ptr is a pointer to function or a serial of GiNaC function.
+// In the former case calls that function, in the latter case constructs
+// GiNaC function with corresponding serial and arguments.
+static ex dispatch_reader_fcn(const reader_func ptr, const exvector& args)
+{
+ unsigned serial = 0; // dear gcc, could you please shut up?
+ bool is_ptr = decode_serial(serial, ptr);
+ if (is_ptr)
+ return ptr(args);
+ else
+ return function(serial, args);
+}
+// </KLUDGE>
+
+
/// identifier_expr: identifier | identifier '(' expression* ')'
ex parser::parse_identifier_expr()
{
Parse_error_("no function \"" << name << "\" with " <<
args.size() << " arguments");
}
- // dirty hack to distinguish between serial numbers of functions and real
- // pointers.
- try {
- GiNaC::function f(reinterpret_cast<unsigned>(reader->second), args);
- return f;
- }
- catch ( std::runtime_error ) {
- 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.
+ ex ret = dispatch_reader_fcn(reader->second, args);
+ return ret;
}
/// paren_expr: '(' expression ')'
return e;
}
-extern numeric* _num_1_p;
-extern ex _ex0;
+extern const ex _ex0;
/// unary_expr: [+-] expression
ex parser::parse_unary_expr()