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authorarseny.kapoulkine <arseny.kapoulkine@99668b35-9821-0410-8761-19e4c4f06640>2010-08-29 15:04:27 +0000
committerarseny.kapoulkine <arseny.kapoulkine@99668b35-9821-0410-8761-19e4c4f06640>2010-08-29 15:04:27 +0000
commit849a5a081b1cd19dd2fa0cb557a0a7503b7d50e7 (patch)
tree8ea0e6763b003089416ac906ca7590f94e2a734e /src
parentc779ee05ce45505ab007990b1b11864923c03e81 (diff)
XPath: Initial support for operation without exceptions
git-svn-id: http://pugixml.googlecode.com/svn/trunk@636 99668b35-9821-0410-8761-19e4c4f06640
Diffstat (limited to 'src')
-rw-r--r--src/pugixml.hpp239
-rw-r--r--src/pugixpath.cpp150
2 files changed, 242 insertions, 147 deletions
diff --git a/src/pugixml.hpp b/src/pugixml.hpp
index 28e9a34..ce48a45 100644
--- a/src/pugixml.hpp
+++ b/src/pugixml.hpp
@@ -56,13 +56,13 @@ namespace std
# endif
#endif
-// No XPath without STL or exceptions
-#if (defined(PUGIXML_NO_STL) || defined(PUGIXML_NO_EXCEPTIONS)) && !defined(PUGIXML_NO_XPATH)
+// No XPath without STL
+#if !defined(PUGIXML_NO_XPATH) && defined(PUGIXML_NO_STL)
# define PUGIXML_NO_XPATH
#endif
// Include exception header for XPath
-#ifndef PUGIXML_NO_XPATH
+#if !defined(PUGIXML_NO_XPATH) && !defined(PUGIXML_NO_EXCEPTIONS)
# include <exception>
#endif
@@ -339,102 +339,9 @@ namespace pugi
#ifndef PUGIXML_NO_XPATH
class xpath_node;
class xpath_node_set;
- class xpath_ast_node;
- class xpath_allocator;
-
- /// XPath query return type classification
- enum xpath_value_type
- {
- xpath_type_none, ///< Unknown type (query failed to compile)
- xpath_type_node_set, ///< Node set (xpath_node_set)
- xpath_type_number, ///< Number
- xpath_type_string, ///< String
- xpath_type_boolean ///< Boolean
- };
-
- /// XPath query return type classification
- /// \deprecated This type is deprecated and will be removed in future versions; use xpath_value_type instead
- typedef xpath_value_type xpath_type_t;
-
- /**
- * A class that holds compiled XPath query and allows to evaluate query result
- */
- class PUGIXML_CLASS xpath_query
- {
- private:
- // Non-copyable semantics
- xpath_query(const xpath_query&);
- xpath_query& operator=(const xpath_query&);
-
- xpath_allocator* m_alloc;
- xpath_ast_node* m_root;
-
- public:
- /**
- * Constructor from string with XPath expression.
- * Throws xpath_exception on compilation error, std::bad_alloc on out of memory error.
- *
- * \param query - string with XPath expression
- */
- explicit xpath_query(const char_t* query);
-
- /**
- * Destructor
- */
- ~xpath_query();
-
- /**
- * Get query expression return type
- *
- * \return expression return type
- **/
- xpath_value_type return_type() const;
-
- /**
- * Evaluate expression as boolean value for the context node \a n.
- * If expression does not directly evaluate to boolean, the expression result is converted
- * as through boolean() XPath function call.
- * Throws std::bad_alloc on out of memory error.
- *
- * \param n - context node
- * \return evaluation result
- */
- bool evaluate_boolean(const xml_node& n) const;
-
- /**
- * Evaluate expression as double value for the context node \a n.
- * If expression does not directly evaluate to double, the expression result is converted
- * as through number() XPath function call.
- * Throws std::bad_alloc on out of memory error.
- *
- * \param n - context node
- * \return evaluation result
- */
- double evaluate_number(const xml_node& n) const;
-
- /**
- * Evaluate expression as string value for the context node \a n.
- * If expression does not directly evaluate to string, the expression result is converted
- * as through string() XPath function call.
- * Throws std::bad_alloc on out of memory error.
- *
- * \param n - context node
- * \return evaluation result
- */
- string_t evaluate_string(const xml_node& n) const;
-
- /**
- * Evaluate expression as node set for the context node \a n.
- * If expression does not directly evaluate to node set, throws xpath_exception.
- * Throws std::bad_alloc on out of memory error.
- *
- * \param n - context node
- * \return evaluation result
- */
- xpath_node_set evaluate_node_set(const xml_node& n) const;
- };
+ class xpath_query;
#endif
-
+
/**
* Abstract writer class
* \see xml_node::print
@@ -2016,21 +1923,146 @@ namespace pugi
};
#ifndef PUGIXML_NO_XPATH
+ class xpath_ast_node;
+ class xpath_allocator;
+
+ /// XPath query return type classification
+ enum xpath_value_type
+ {
+ xpath_type_none, ///< Unknown type (query failed to compile)
+ xpath_type_node_set, ///< Node set (xpath_node_set)
+ xpath_type_number, ///< Number
+ xpath_type_string, ///< String
+ xpath_type_boolean ///< Boolean
+ };
+
+ /// XPath query return type classification
+ /// \deprecated This type is deprecated and will be removed in future versions; use xpath_value_type instead
+ typedef xpath_value_type xpath_type_t;
+
+ struct PUGIXML_CLASS xpath_parse_result
+ {
+ /// Error message (0 if no error)
+ const char* error;
+
+ /// Last parsed offset (in characters from string start)
+ ptrdiff_t offset;
+
+ /// Cast to bool operator
+ operator bool() const
+ {
+ return error == 0;
+ }
+
+ /// Get error description
+ const char* description() const;
+ };
+
+ /**
+ * A class that holds compiled XPath query and allows to evaluate query result
+ */
+ class PUGIXML_CLASS xpath_query
+ {
+ private:
+ // Non-copyable semantics
+ xpath_query(const xpath_query&);
+ xpath_query& operator=(const xpath_query&);
+
+ xpath_allocator* m_alloc;
+ xpath_ast_node* m_root;
+ xpath_parse_result _result;
+
+ typedef xpath_ast_node* xpath_query::*unspecified_bool_type;
+
+ public:
+ /**
+ * Constructor from string with XPath expression.
+ * Throws xpath_exception on compilation error, std::bad_alloc on out of memory error.
+ *
+ * \param query - string with XPath expression
+ */
+ explicit xpath_query(const char_t* query);
+
+ /**
+ * Destructor
+ */
+ ~xpath_query();
+
+ /**
+ * Get query expression return type
+ *
+ * \return expression return type
+ **/
+ xpath_value_type return_type() const;
+
+ /**
+ * Evaluate expression as boolean value for the context node \a n.
+ * If expression does not directly evaluate to boolean, the expression result is converted
+ * as through boolean() XPath function call.
+ * Throws std::bad_alloc on out of memory error.
+ *
+ * \param n - context node
+ * \return evaluation result
+ */
+ bool evaluate_boolean(const xml_node& n) const;
+
+ /**
+ * Evaluate expression as double value for the context node \a n.
+ * If expression does not directly evaluate to double, the expression result is converted
+ * as through number() XPath function call.
+ * Throws std::bad_alloc on out of memory error.
+ *
+ * \param n - context node
+ * \return evaluation result
+ */
+ double evaluate_number(const xml_node& n) const;
+
+ /**
+ * Evaluate expression as string value for the context node \a n.
+ * If expression does not directly evaluate to string, the expression result is converted
+ * as through string() XPath function call.
+ * Throws std::bad_alloc on out of memory error.
+ *
+ * \param n - context node
+ * \return evaluation result
+ */
+ string_t evaluate_string(const xml_node& n) const;
+
+ /**
+ * Evaluate expression as node set for the context node \a n.
+ * If expression does not directly evaluate to node set, throws xpath_exception.
+ * Throws std::bad_alloc on out of memory error.
+ *
+ * \param n - context node
+ * \return evaluation result
+ */
+ xpath_node_set evaluate_node_set(const xml_node& n) const;
+
+ // Get parsing result
+ const xpath_parse_result& result() const;
+
+ // Safe bool conversion
+ operator unspecified_bool_type() const;
+
+ // Borland C++ workaround
+ bool operator!() const;
+ };
+
+ #ifndef PUGIXML_NO_EXCEPTIONS
/**
* XPath exception class.
*/
class PUGIXML_CLASS xpath_exception: public std::exception
{
private:
- const char* m_message;
+ xpath_parse_result _result;
public:
/**
- * Construct exception from static error string
+ * Construct exception from parse result
*
- * \param message - error string
*/
- explicit xpath_exception(const char* message);
+ explicit xpath_exception(const xpath_parse_result& result);
/**
* Return error message
@@ -2038,7 +2070,10 @@ namespace pugi
* \return error message
*/
virtual const char* what() const throw();
+
+ const xpath_parse_result& result() const;
};
+ #endif
/**
* XPath node class.
diff --git a/src/pugixpath.cpp b/src/pugixpath.cpp
index 450a907..732a3c6 100644
--- a/src/pugixpath.cpp
+++ b/src/pugixpath.cpp
@@ -19,6 +19,7 @@
#include <stdio.h>
#include <string.h>
#include <assert.h>
+#include <setjmp.h>
#include <ctype.h>
#include <math.h>
#include <float.h>
@@ -36,6 +37,8 @@ typedef __int32 int32_t;
#if defined(_MSC_VER)
# pragma warning(disable: 4127) // conditional expression is constant
+# pragma warning(disable: 4611) // interaction between '_setjmp' and C++ object destruction is non-portable
+# pragma warning(disable: 4324) // structure was padded due to __declspec(align())
# pragma warning(disable: 4996) // this function or variable may be unsafe
#endif
@@ -48,7 +51,6 @@ typedef __int32 int32_t;
#endif
#include <algorithm>
-#include <memory>
#include <string>
// String utilities prototypes
@@ -601,14 +603,22 @@ namespace
namespace pugi
{
- xpath_exception::xpath_exception(const char* message): m_message(message)
+#ifndef PUGIXML_NO_EXCEPTIONS
+ xpath_exception::xpath_exception(const xpath_parse_result& result): _result(result)
{
+ assert(result.error);
}
const char* xpath_exception::what() const throw()
{
- return m_message;
+ return _result.error;
}
+
+ const xpath_parse_result& xpath_exception::result() const
+ {
+ return _result;
+ }
+#endif
const size_t xpath_memory_block_size = 4096; ///< Memory block size, 4 kb
@@ -2554,20 +2564,29 @@ namespace pugi
return alloc(sizeof(xpath_ast_node));
}
- class xpath_parser
+ struct xpath_parser
{
- private:
xpath_allocator& m_alloc;
xpath_lexer m_lexer;
+ xpath_parse_result* m_result;
+ jmp_buf m_error_handler;
xpath_parser(const xpath_parser&);
xpath_parser& operator=(const xpath_parser&);
+ void throw_error(const char* message)
+ {
+ m_result->error = message;
+ m_result->offset = 0; // $$$ lexer
+
+ longjmp(m_error_handler, 1);
+ }
+
xpath_ast_node* parse_function_helper(ast_type_t type0, ast_type_t type1, size_t argc, xpath_ast_node* args[2])
{
assert(argc <= 1);
- if (argc == 1 && args[0]->rettype() != xpath_type_node_set) throw xpath_exception("Function has to be applied to node set");
+ if (argc == 1 && args[0]->rettype() != xpath_type_node_set) throw_error("Function has to be applied to node set");
return new (m_alloc.node()) xpath_ast_node(argc == 0 ? type0 : type1, xpath_type_string, args[0]);
}
@@ -2585,7 +2604,7 @@ namespace pugi
case 'c':
if (name == PUGIXML_TEXT("count") && argc == 1)
{
- if (args[0]->rettype() != xpath_type_node_set) throw xpath_exception("count() has to be applied to node set");
+ if (args[0]->rettype() != xpath_type_node_set) throw_error("count() has to be applied to node set");
return new (m_alloc.node()) xpath_ast_node(ast_func_count, xpath_type_number, args[0]);
}
else if (name == PUGIXML_TEXT("contains") && argc == 2)
@@ -2662,7 +2681,7 @@ namespace pugi
return new (m_alloc.node()) xpath_ast_node(argc == 2 ? ast_func_substring_2 : ast_func_substring_3, xpath_type_string, args[0], args[1]);
else if (name == PUGIXML_TEXT("sum") && argc == 1)
{
- if (args[0]->rettype() != xpath_type_node_set) throw xpath_exception("sum() has to be applied to node set");
+ if (args[0]->rettype() != xpath_type_node_set) throw_error("sum() has to be applied to node set");
return new (m_alloc.node()) xpath_ast_node(ast_func_sum, xpath_type_number, args[0]);
}
@@ -2677,11 +2696,9 @@ namespace pugi
break;
}
- throw xpath_exception("Unrecognized function or wrong parameter count");
+ throw_error("Unrecognized function or wrong parameter count");
- #ifdef __DMC__
- return 0; // Digital Mars C++
- #endif
+ return 0;
}
axis_t parse_axis_name(const xpath_lexer_string& name, bool& specified)
@@ -2788,11 +2805,9 @@ namespace pugi
{
case lex_var_ref:
{
- throw xpath_exception("Variables are not supported");
+ throw_error("Variables are not supported");
- #ifdef __DMC__
- return 0; // Digital Mars C++
- #endif
+ return 0;
}
case lex_open_brace:
@@ -2802,7 +2817,7 @@ namespace pugi
xpath_ast_node* n = parse_expression();
if (m_lexer.current() != lex_close_brace)
- throw xpath_exception("Unmatched braces");
+ throw_error("Unmatched braces");
m_lexer.next();
@@ -2838,7 +2853,7 @@ namespace pugi
xpath_ast_node* last_arg = 0;
if (m_lexer.current() != lex_open_brace)
- throw xpath_exception("Unrecognized function call");
+ throw_error("Unrecognized function call");
m_lexer.next();
if (m_lexer.current() != lex_close_brace)
@@ -2847,7 +2862,7 @@ namespace pugi
while (m_lexer.current() != lex_close_brace)
{
if (m_lexer.current() != lex_comma)
- throw xpath_exception("No comma between function arguments");
+ throw_error("No comma between function arguments");
m_lexer.next();
xpath_ast_node* n = parse_expression();
@@ -2865,10 +2880,9 @@ namespace pugi
}
default:
- throw xpath_exception("Unrecognizable primary expression");
- #ifdef __DMC__
- return 0; // Digital Mars C++
- #endif
+ throw_error("Unrecognizable primary expression");
+
+ return 0;
}
}
@@ -2885,14 +2899,14 @@ namespace pugi
xpath_ast_node* expr = parse_expression();
- if (n->rettype() != xpath_type_node_set) throw xpath_exception("Predicate has to be applied to node set");
+ if (n->rettype() != xpath_type_node_set) throw_error("Predicate has to be applied to node set");
bool posinv = expr->rettype() != xpath_type_number && expr->is_posinv();
n = new (m_alloc.node()) xpath_ast_node(posinv ? ast_filter_posinv : ast_filter, xpath_type_node_set, n, expr);
if (m_lexer.current() != lex_close_square_brace)
- throw xpath_exception("Unmatched square brace");
+ throw_error("Unmatched square brace");
m_lexer.next();
}
@@ -2908,7 +2922,7 @@ namespace pugi
xpath_ast_node* parse_step(xpath_ast_node* set)
{
if (set && set->rettype() != xpath_type_node_set)
- throw xpath_exception("Step has to be applied to node set");
+ throw_error("Step has to be applied to node set");
bool axis_specified = false;
axis_t axis = axis_child; // implied child axis
@@ -2946,11 +2960,11 @@ namespace pugi
if (m_lexer.current() == lex_double_colon)
{
// parse axis name
- if (axis_specified) throw xpath_exception("Two axis specifiers in one step");
+ if (axis_specified) throw_error("Two axis specifiers in one step");
axis = parse_axis_name(nt_name, axis_specified);
- if (!axis_specified) throw xpath_exception("Unknown axis");
+ if (!axis_specified) throw_error("Unknown axis");
// read actual node test
m_lexer.next();
@@ -2966,7 +2980,7 @@ namespace pugi
nt_name = m_lexer.contents();
m_lexer.next();
}
- else throw xpath_exception("Unrecognized node test");
+ else throw_error("Unrecognized node test");
}
if (nt_type == nodetest_none)
@@ -2982,25 +2996,25 @@ namespace pugi
nt_type = parse_node_test_type(nt_name);
- if (nt_type == nodetest_none) throw xpath_exception("Unrecognized node type");
+ if (nt_type == nodetest_none) throw_error("Unrecognized node type");
nt_name = xpath_lexer_string();
}
else if (nt_name == PUGIXML_TEXT("processing-instruction"))
{
if (m_lexer.current() != lex_quoted_string)
- throw xpath_exception("Only literals are allowed as arguments to processing-instruction()");
+ throw_error("Only literals are allowed as arguments to processing-instruction()");
nt_type = nodetest_pi;
nt_name = m_lexer.contents();
m_lexer.next();
if (m_lexer.current() != lex_close_brace)
- throw xpath_exception("Unmatched brace near processing-instruction()");
+ throw_error("Unmatched brace near processing-instruction()");
m_lexer.next();
}
else
- throw xpath_exception("Unmatched brace near node type test");
+ throw_error("Unmatched brace near node type test");
}
// QName or NCName:*
@@ -3023,7 +3037,7 @@ namespace pugi
nt_type = nodetest_all;
m_lexer.next();
}
- else throw xpath_exception("Unrecognized node test");
+ else throw_error("Unrecognized node test");
xpath_ast_node* n = new (m_alloc.node()) xpath_ast_node(ast_step, set, axis, nt_type, nt_name, m_alloc);
@@ -3038,7 +3052,7 @@ namespace pugi
xpath_ast_node* pred = new (m_alloc.node()) xpath_ast_node(ast_predicate, xpath_type_node_set, expr);
if (m_lexer.current() != lex_close_square_brace)
- throw xpath_exception("Unmatched square brace");
+ throw_error("Unmatched square brace");
m_lexer.next();
if (last) last->set_next(pred);
@@ -3141,7 +3155,7 @@ namespace pugi
if (l == lex_double_slash)
{
- if (n->rettype() != xpath_type_node_set) throw xpath_exception("Step has to be applied to node set");
+ if (n->rettype() != xpath_type_node_set) throw_error("Step has to be applied to node set");
n = new (m_alloc.node()) xpath_ast_node(ast_step, n, axis_descendant_or_self, nodetest_type_node, xpath_lexer_string(), m_alloc);
}
@@ -3167,7 +3181,7 @@ namespace pugi
xpath_ast_node* expr = parse_union_expression();
if (n->rettype() != xpath_type_node_set || expr->rettype() != xpath_type_node_set)
- throw xpath_exception("Union operator has to be applied to node sets");
+ throw_error("Union operator has to be applied to node sets");
n = new (m_alloc.node()) xpath_ast_node(ast_op_union, xpath_type_node_set, n, expr);
}
@@ -3318,8 +3332,7 @@ namespace pugi
return parse_or_expression();
}
- public:
- explicit xpath_parser(const char_t* query, xpath_allocator& alloc): m_alloc(alloc), m_lexer(query)
+ xpath_parser(const char_t* query, xpath_allocator& alloc, xpath_parse_result* result): m_alloc(alloc), m_lexer(query), m_result(result)
{
}
@@ -3330,21 +3343,44 @@ namespace pugi
if (m_lexer.current() != lex_eof)
{
// there are still unparsed tokens left, error
- throw xpath_exception("Incorrect query");
+ throw_error("Incorrect query");
}
return result;
}
};
+ const char* xpath_parse_result::description() const
+ {
+ return error ? error : "Success";
+ }
+
xpath_query::xpath_query(const char_t* query): m_alloc(0), m_root(0)
{
- std::auto_ptr<xpath_allocator> alloc(new xpath_allocator);
+ m_alloc = new xpath_allocator;
+
+ xpath_parser parser(query, *m_alloc, &_result);
- xpath_parser p(query, *alloc);
+ int error = setjmp(parser.m_error_handler);
- m_root = p.parse();
- m_alloc = alloc.release();
+ if (error == 0)
+ {
+ m_root = parser.parse();
+
+ _result.error = 0;
+ _result.offset = 0;
+ }
+ else
+ {
+ delete m_alloc;
+
+ m_root = 0;
+ m_alloc = 0;
+
+ #ifndef PUGIXML_NO_EXCEPTIONS
+ throw xpath_exception(_result);
+ #endif
+ }
}
xpath_query::~xpath_query()
@@ -3389,13 +3425,37 @@ namespace pugi
xpath_node_set xpath_query::evaluate_node_set(const xml_node& n) const
{
if (!m_root) return xpath_node_set();
- if (m_root->rettype() != xpath_type_node_set) throw xpath_exception("Expression does not evaluate to node set");
+
+ if (m_root->rettype() != xpath_type_node_set)
+ {
+ #ifdef PUGIXML_NO_EXCEPTIONS
+ return xpath_node_set()
+ #else
+ xpath_parse_result result = {"Expression does not evaluate to node set", 0};
+ throw xpath_exception(result);
+ #endif
+ }
xpath_context c(n, 1, 1);
return m_root->eval_node_set(c);
}
+ const xpath_parse_result& xpath_query::result() const
+ {
+ return _result;
+ }
+
+ xpath_query::operator unspecified_bool_type() const
+ {
+ return m_root ? &xpath_query::m_root : 0;
+ }
+
+ bool xpath_query::operator!() const
+ {
+ return !m_root;
+ }
+
xpath_node xml_node::select_single_node(const char_t* query) const
{
xpath_query q(query);