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Simplify XML parsing a bit.
- From: Pedro Alves <pedro at codesourcery dot com>
- To: gdb-patches at sourceware dot org
- Date: Tue, 25 Jan 2011 09:50:31 +0000
- Subject: Simplify XML parsing a bit.
I find the the cleanup handling around calling gdb_parse a
bit more complicated than it needs to be. At least, I always find
myself needing to think about it carefuly.
This patch factors out a bit of code that all gdb_parse callers
end up doing into a new gdb_parse_quick function. And then,
simplifies current gdb_parse callers by instead using this
new function.
I couldn't come up with a better name for the function. I was
using "gdb_parse_once" in a previous version of the patch...
Tested on x86_64-linux native&gdbserver and applied.
--
Pedro Alves
2011-01-25 Pedro Alves <pedro@codesourcery.com>
Simplify XML parsing a bit.
gdb/
* xml-support.h (gdb_xml_parse_quick): Declare.
* xml-support.c (gdb_xml_create_parser_and_cleanup_1): Renamed
from gdb_xml_create_parser_and_cleanup, and added `old_chain'
parameter.
(gdb_xml_create_parser_and_cleanup): Reimplement on top of
gdb_xml_create_parser_and_cleanup_1.
(gdb_xml_parse_quick): New.
* memory-map.c (parse_memory_map): Use gdb_xml_parse_quick.
* osdata.c (osdata_parse): Ditto.
* remote.c (remote_threads_info): Ditto.
* solib-target.c (solib_target_parse_libraries): Ditto.
* xml-syscall.c (syscall_parse_xml): Ditto.
* xml-tdesc.c (tdesc_parse_xml): Ditto.
---
gdb/memory-map.c | 23 ++++++++++-------------
gdb/osdata.c | 22 ++++++++++------------
gdb/remote.c | 21 +++++----------------
gdb/solib-target.c | 24 ++++++++++--------------
gdb/xml-support.c | 47 ++++++++++++++++++++++++++++++++++++++++++-----
gdb/xml-support.h | 12 ++++++++++++
gdb/xml-syscall.c | 8 ++------
gdb/xml-tdesc.c | 7 ++-----
8 files changed, 93 insertions(+), 71 deletions(-)
Index: src/gdb/xml-support.c
===================================================================
--- src.orig/gdb/xml-support.c 2011-01-25 09:31:36.567639998 +0000
+++ src/gdb/xml-support.c 2011-01-25 09:39:16.687639991 +0000
@@ -427,13 +427,14 @@ gdb_xml_cleanup (void *arg)
/* Initialize and return a parser. Register a cleanup to destroy the
parser. */
-struct gdb_xml_parser *
-gdb_xml_create_parser_and_cleanup (const char *name,
- const struct gdb_xml_element *elements,
- void *user_data)
+static struct gdb_xml_parser *
+gdb_xml_create_parser_and_cleanup_1 (const char *name,
+ const struct gdb_xml_element *elements,
+ void *user_data, struct cleanup **old_chain)
{
struct gdb_xml_parser *parser;
struct scope_level start_scope;
+ struct cleanup *dummy;
/* Initialize the parser. */
parser = XZALLOC (struct gdb_xml_parser);
@@ -459,11 +460,27 @@ gdb_xml_create_parser_and_cleanup (const
start_scope.elements = elements;
VEC_safe_push (scope_level_s, parser->scopes, &start_scope);
- make_cleanup (gdb_xml_cleanup, parser);
+ if (old_chain == NULL)
+ old_chain = &dummy;
+ *old_chain = make_cleanup (gdb_xml_cleanup, parser);
return parser;
}
+/* Initialize and return a parser. Register a cleanup to destroy the
+ parser. */
+
+struct gdb_xml_parser *
+gdb_xml_create_parser_and_cleanup (const char *name,
+ const struct gdb_xml_element *elements,
+ void *user_data)
+{
+ struct cleanup *old_chain;
+
+ return gdb_xml_create_parser_and_cleanup_1 (name, elements, user_data,
+ &old_chain);
+}
+
/* External entity handler. The only external entities we support
are those compiled into GDB (we do not fetch entities from the
target). */
@@ -581,6 +598,26 @@ gdb_xml_parse (struct gdb_xml_parser *pa
return -1;
}
+int
+gdb_xml_parse_quick (const char *name, const char *dtd_name,
+ const struct gdb_xml_element *elements,
+ const char *document, void *user_data)
+{
+ struct gdb_xml_parser *parser;
+ struct cleanup *back_to;
+ int result;
+
+ parser = gdb_xml_create_parser_and_cleanup_1 (name, elements,
+ user_data, &back_to);
+ if (dtd_name != NULL)
+ gdb_xml_use_dtd (parser, dtd_name);
+ result = gdb_xml_parse (parser, document);
+
+ do_cleanups (back_to);
+
+ return result;
+}
+
/* Parse a field VALSTR that we expect to contain an integer value.
The integer is returned in *VALP. The string is parsed with an
equivalent to strtoul.
Index: src/gdb/xml-support.h
===================================================================
--- src.orig/gdb/xml-support.h 2011-01-25 09:31:36.567639998 +0000
+++ src/gdb/xml-support.h 2011-01-25 09:39:16.687639991 +0000
@@ -197,6 +197,18 @@ void gdb_xml_use_dtd (struct gdb_xml_par
int gdb_xml_parse (struct gdb_xml_parser *parser, const char *buffer);
+/* Parse a XML document. DOCUMENT is the data to parse, which should
+ be NUL-terminated. If non-NULL, use the compiled-in DTD named
+ DTD_NAME to drive the parsing.
+
+ The return value is 0 for success or -1 for error. It may throw,
+ but only if something unexpected goes wrong during parsing; parse
+ errors will be caught, warned about, and reported as failure. */
+
+int gdb_xml_parse_quick (const char *name, const char *dtd_name,
+ const struct gdb_xml_element *elements,
+ const char *document, void *user_data);
+
/* Issue a debugging message from one of PARSER's handlers. */
void gdb_xml_debug (struct gdb_xml_parser *parser, const char *format, ...)
Index: src/gdb/memory-map.c
===================================================================
--- src.orig/gdb/memory-map.c 2011-01-25 09:31:36.567639998 +0000
+++ src/gdb/memory-map.c 2011-01-25 09:39:16.687639991 +0000
@@ -178,25 +178,22 @@ const struct gdb_xml_element memory_map_
VEC(mem_region_s) *
parse_memory_map (const char *memory_map)
{
- struct gdb_xml_parser *parser;
VEC(mem_region_s) *result = NULL;
- struct cleanup *before_deleting_result, *back_to;
+ struct cleanup *back_to;
struct memory_map_parsing_data data = { NULL };
- back_to = make_cleanup (null_cleanup, NULL);
- parser = gdb_xml_create_parser_and_cleanup (_("target memory map"),
- memory_map_elements, &data);
-
- /* Note: 'clear_result' will zero 'result'. */
- before_deleting_result = make_cleanup (clear_result, &result);
data.memory_map = &result;
-
- if (gdb_xml_parse (parser, memory_map) == 0)
- /* Parsed successfully, don't need to delete the result. */
- discard_cleanups (before_deleting_result);
+ back_to = make_cleanup (clear_result, &result);
+ if (gdb_xml_parse_quick (_("target memory map"), NULL, memory_map_elements,
+ memory_map, &data) == 0)
+ {
+ /* Parsed successfully, keep the result. */
+ discard_cleanups (back_to);
+ return result;
+ }
do_cleanups (back_to);
- return result;
+ return NULL;
}
#endif /* HAVE_LIBEXPAT */
Index: src/gdb/osdata.c
===================================================================
--- src.orig/gdb/osdata.c 2011-01-25 09:31:36.567639998 +0000
+++ src/gdb/osdata.c 2011-01-25 09:39:16.697639988 +0000
@@ -168,23 +168,21 @@ const struct gdb_xml_element osdata_elem
struct osdata *
osdata_parse (const char *xml)
{
- struct gdb_xml_parser *parser;
- struct cleanup *before_deleting_result, *back_to;
+ struct cleanup *back_to;
struct osdata_parsing_data data = { NULL };
- back_to = make_cleanup (null_cleanup, NULL);
- parser = gdb_xml_create_parser_and_cleanup (_("osdata"),
- osdata_elements, &data);
- gdb_xml_use_dtd (parser, "osdata.dtd");
+ back_to = make_cleanup (clear_parsing_data, &data);
- before_deleting_result = make_cleanup (clear_parsing_data, &data);
-
- if (gdb_xml_parse (parser, xml) == 0)
- /* Parsed successfully, don't need to delete the result. */
- discard_cleanups (before_deleting_result);
+ if (gdb_xml_parse_quick (_("osdata"), "osdata.dtd",
+ osdata_elements, xml, &data) == 0)
+ {
+ /* Parsed successfully, don't need to delete the result. */
+ discard_cleanups (back_to);
+ return data.osdata;
+ }
do_cleanups (back_to);
- return data.osdata;
+ return NULL;
}
#endif
Index: src/gdb/remote.c
===================================================================
--- src.orig/gdb/remote.c 2011-01-25 09:31:36.567639998 +0000
+++ src/gdb/remote.c 2011-01-25 09:39:16.697639988 +0000
@@ -2595,25 +2595,16 @@ remote_threads_info (struct target_ops *
TARGET_OBJECT_THREADS, NULL);
struct cleanup *back_to = make_cleanup (xfree, xml);
+
if (xml && *xml)
{
- struct gdb_xml_parser *parser;
struct threads_parsing_context context;
- struct cleanup *clear_parsing_context;
-
- context.items = 0;
- /* Note: this parser cleanup is already guarded by BACK_TO
- above. */
- parser = gdb_xml_create_parser_and_cleanup (_("threads"),
- threads_elements,
- &context);
- gdb_xml_use_dtd (parser, "threads.dtd");
+ context.items = NULL;
+ make_cleanup (clear_threads_parsing_context, &context);
- clear_parsing_context
- = make_cleanup (clear_threads_parsing_context, &context);
-
- if (gdb_xml_parse (parser, xml) == 0)
+ if (gdb_xml_parse_quick (_("threads"), "threads.dtd",
+ threads_elements, xml, &context) == 0)
{
int i;
struct thread_item *item;
@@ -2640,8 +2631,6 @@ remote_threads_info (struct target_ops *
}
}
}
-
- do_cleanups (clear_parsing_context);
}
do_cleanups (back_to);
Index: src/gdb/solib-target.c
===================================================================
--- src.orig/gdb/solib-target.c 2011-01-25 09:31:36.567639998 +0000
+++ src/gdb/solib-target.c 2011-01-25 09:39:16.697639988 +0000
@@ -227,24 +227,20 @@ const struct gdb_xml_element library_lis
static VEC(lm_info_p) *
solib_target_parse_libraries (const char *library)
{
- struct gdb_xml_parser *parser;
VEC(lm_info_p) *result = NULL;
- struct cleanup *before_deleting_result, *back_to;
+ struct cleanup *back_to = make_cleanup (solib_target_free_library_list,
+ &result);
- back_to = make_cleanup (null_cleanup, NULL);
- parser = gdb_xml_create_parser_and_cleanup (_("target library list"),
- library_list_elements, &result);
- gdb_xml_use_dtd (parser, "library-list.dtd");
-
- before_deleting_result = make_cleanup (solib_target_free_library_list,
- &result);
-
- if (gdb_xml_parse (parser, library) == 0)
- /* Parsed successfully, don't need to delete the result. */
- discard_cleanups (before_deleting_result);
+ if (gdb_xml_parse_quick (_("target library list"), "library-list.dtd",
+ library_list_elements, library, &result) == 0)
+ {
+ /* Parsed successfully, keep the result. */
+ discard_cleanups (back_to);
+ return result;
+ }
do_cleanups (back_to);
- return result;
+ return NULL;
}
#endif
Index: src/gdb/xml-syscall.c
===================================================================
--- src.orig/gdb/xml-syscall.c 2011-01-25 09:31:36.567639998 +0000
+++ src/gdb/xml-syscall.c 2011-01-25 09:39:16.697639988 +0000
@@ -224,17 +224,13 @@ syscall_parse_xml (const char *document,
void *fetcher_baton)
{
struct cleanup *result_cleanup;
- struct gdb_xml_parser *parser;
struct syscall_parsing_data data;
- parser = gdb_xml_create_parser_and_cleanup (_("syscalls info"),
- syselements, &data);
-
- memset (&data, 0, sizeof (struct syscall_parsing_data));
data.sysinfo = allocate_syscalls_info ();
result_cleanup = make_cleanup_free_syscalls_info (data.sysinfo);
- if (gdb_xml_parse (parser, document) == 0)
+ if (gdb_xml_parse_quick (_("syscalls info"), NULL,
+ syselements, document, &data) == 0)
{
/* Parsed successfully. */
discard_cleanups (result_cleanup);
Index: src/gdb/xml-tdesc.c
===================================================================
--- src.orig/gdb/xml-tdesc.c 2011-01-25 09:31:36.567639998 +0000
+++ src/gdb/xml-tdesc.c 2011-01-25 09:39:16.697639988 +0000
@@ -505,7 +505,6 @@ tdesc_parse_xml (const char *document, x
void *fetcher_baton)
{
struct cleanup *back_to, *result_cleanup;
- struct gdb_xml_parser *parser;
struct tdesc_parsing_data data;
struct tdesc_xml_cache *cache;
char *expanded_text;
@@ -531,16 +530,14 @@ tdesc_parse_xml (const char *document, x
}
back_to = make_cleanup (null_cleanup, NULL);
- parser = gdb_xml_create_parser_and_cleanup (_("target description"),
- tdesc_elements, &data);
- gdb_xml_use_dtd (parser, "gdb-target.dtd");
memset (&data, 0, sizeof (struct tdesc_parsing_data));
data.tdesc = allocate_target_description ();
result_cleanup = make_cleanup_free_target_description (data.tdesc);
make_cleanup (xfree, expanded_text);
- if (gdb_xml_parse (parser, expanded_text) == 0)
+ if (gdb_xml_parse_quick (_("target description"), "gdb-target.dtd",
+ tdesc_elements, expanded_text, &data) == 0)
{
/* Parsed successfully. */
struct tdesc_xml_cache new_cache;