Revised the way that exceptions are thrown around. Instead of context being a

complicated string of pointers, it's now just a global block of text that gets
appended to as the error is being thrown up, and can be displayed at the catch
point if desired.  There are almost no cases where a thrown exception will not
result in an error message being displayed to the user.

1 files changed, 75 insertions, 123 deletions

diff --git a/error.h b/error.h
index 16cb197e..4eaf72a8 100644
--- a/error.h
+++ b/error.h
@@ -1,132 +1,84 @@
+/*
+ * Copyright (c) 2003-2008, John Wiegley.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ *
+ * - Neither the name of New Artisans LLC nor the names of its
+ *   contributors may be used to endorse or promote products derived from
+ *   this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
 #ifndef _ERROR_H
 #define _ERROR_H
 
-#include <exception>
-#include <stdexcept>
-#include <string>
-#include <cstring>
-#include <sstream>
-#include <list>
-
 namespace ledger {
 
-class error_context
-{
-public:
-  string desc;
-
-  error_context(const string& _desc) throw() : desc(_desc) {}
-  virtual ~error_context() throw() {}
-  virtual void describe(std::ostream& out) const throw() {
-    if (! desc.empty())
-      out << desc << std::endl;
-  }
-};
-
-class file_context : public error_context
-{
- protected:
-  path		file;
-  unsigned long line;
- public:
-  file_context(const path& _file, unsigned long _line,
-	       const string& desc = "") throw()
-    : error_context(desc), file(_file), line(_line) {}
-  virtual ~file_context() throw() {}
-
-  virtual void describe(std::ostream& out) const throw() {
-    if (! desc.empty())
-      out << desc << " ";
-
-    out << "\"" << file << "\", line " << line << ": ";
+extern std::ostringstream _desc_buffer;
+
+template <typename T>
+inline void throw_func(const std::string& message) {
+  _desc_buffer.str("");
+  throw T(message);
+}
+
+#define throw_(cls, msg)					\
+  ((_desc_buffer << msg), throw_func<cls>(_desc_buffer.str()))
+
+extern std::ostringstream _ctxt_buffer;
+
+#define add_error_context(msg)					\
+  ((static_cast<unsigned long>(_ctxt_buffer.tellp()) == 0) ?	\
+   (_ctxt_buffer << msg) : (_ctxt_buffer << std::endl << msg))
+
+inline string error_context() {
+  string context = _ctxt_buffer.str();
+  _ctxt_buffer.str("");
+  return context;
+}
+
+inline string file_context(const path& file, std::size_t line) {
+  std::ostringstream buf;
+  buf << "\"" << file << "\", line " << line << ": ";
+  return buf.str();
+}
+
+inline string line_context(const string& line, long pos) {
+  std::ostringstream buf;
+  buf << "  " << line << std::endl << "  ";
+  long idx = pos < 0 ? line.length() - 1 : pos;
+  for (int i = 0; i < idx; i++)
+    buf << " ";
+  buf << "^" << std::endl;
+  return buf.str();
+}
+
+#define DECLARE_EXCEPTION(name, kind)				\
+  class name : public kind {					\
+  public:							\
+  explicit name(const string& why) throw() : kind(why) {}	\
+  virtual ~name() throw() {}					\
   }
-};
-
-class line_context : public error_context
-{
-public:
-  string line;
-  long	      pos;
-
-  line_context(const string& _line, long _pos,
-	       const string& desc = "") throw()
-    : error_context(desc), line(_line), pos(_pos) {}
-  virtual ~line_context() throw() {}
-
-  virtual void describe(std::ostream& out) const throw() {
-    if (! desc.empty())
-      out << desc << std::endl;
-
-    out << "  " << line << std::endl << "  ";
-    long idx = pos < 0 ? line.length() - 1 : pos;
-    for (int i = 0; i < idx; i++)
-      out << " ";
-    out << "^" << std::endl;
-  }
-};
-
-//////////////////////////////////////////////////////////////////////
-
-class str_exception : public std::logic_error
-{
-public:
-  std::list<error_context *> context;
-
-  str_exception(const string& why,
-		error_context * ctxt = NULL) throw()
-    : std::logic_error(why), context() {
-    if (ctxt)
-      context.push_back(ctxt);
-  }
-
-  virtual ~str_exception() throw() {
-    for (std::list<error_context *>::iterator i = context.begin();
-	 i != context.end();
-	 i++)
-      checked_delete(*i);
-  }
-
-  virtual void reveal_context(std::ostream& out,
-			      const string& kind) const throw() {
-    for (std::list<error_context *>::const_reverse_iterator i =
-	   context.rbegin();
-	 i != context.rend();
-	 i++) {
-      std::list<error_context *>::const_reverse_iterator x = i;
-      if (++x == context.rend())
-	out << kind << ": ";
-      (*i)->describe(out);
-    }
-  }
-};
-
-#define DECLARE_EXCEPTION(kind, name)					\
-  class name : public kind {						\
-  public:								\
-    name(const string& why, error_context * ctxt = NULL) throw()	\
-      : kind(why, ctxt) {}						\
-  }
-
-class error : public str_exception {
- public:
-  error(const string& why, error_context * ctxt = NULL) throw()
-    : str_exception(why, ctxt) {}
-  virtual ~error() throw() {}
-};
-
-class fatal : public str_exception {
- public:
-  fatal(const string& why, error_context * ctxt = NULL) throw()
-    : str_exception(why, ctxt) {}
-  virtual ~fatal() throw() {}
-};
-
-class fatal_assert : public fatal {
- public:
-  fatal_assert(const string& why, error_context * ctxt = NULL) throw()
-    : fatal(string("assertion failed '") + why + "'", ctxt) {}
-  virtual ~fatal_assert() throw() {}
-};
 
 } // namespace ledger