Add tests for field offset computations

tests/offsets/offsets.h: Header file with structure definitions to test

tests/offsets/gen-gitestoffsets: Generate a C program that computes
  field offsets for the structures in offsets.h two ways: using
  the information from a generated typelib, and as computed by the
  compiler.

We diff these two versions to test that everything is OK.

svn path=/trunk/; revision=878

1 files changed, 242 insertions, 0 deletions

diff --git a/tests/offsets/gen-gitestoffsets b/tests/offsets/gen-gitestoffsets
new file mode 100755
index 00000000..27fff23b
--- /dev/null
+++ b/tests/offsets/gen-gitestoffsets
@@ -0,0 +1,242 @@
+#!/bin/env python
+# -*- Mode: Python -*-
+# GObject-Introspection - a framework for introspecting GObject libraries
+# Copyright (C) 2008  Red Hat, Inc.
+#
+# 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.
+#
+
+# The idea here is that we want to compare offset information two ways:
+#
+#  1) As generated by the compiler
+#  2) As found in the typelib
+#
+# So we find all the structures in the input file (offsets.h), parse out
+# fields within the structure and generate code that outputs the field
+# offsets using G_STRUCT_OFFSET() to one file and the field offsets using
+# the typelib to the another file. We can then diff the two files to see
+# if they are the same
+
+import re
+import sys
+
+if len(sys.argv) != 2:
+    print >>sys.stderr, "Usage: gen-gitestoffsets INPUT > OUTPUT"
+    sys.exit(1)
+
+# Helper function that we use to generate source. It does substitions
+# from a dictionary, removes white space at the ends and removes a
+# leading '|' from each line
+STRIP_AROUND_RE = re.compile("^[ \t]*\n?(.*?)[ \t]*$", re.DOTALL)
+STRIP_LEADER_RE = re.compile("^\|", re.MULTILINE)
+def output(args, format):
+    format = STRIP_AROUND_RE.sub(r"\1", format)
+    format = STRIP_LEADER_RE.sub(r"", format)
+    sys.stdout.write(format % args)
+
+#
+# Some regular expressions we use when parsing
+#
+TOKEN = "(?:[A-Za-z_][A-Za-z_0-9]+)"
+
+def compile_re(expr):
+    expr = expr.replace("TOKEN", TOKEN)
+    return re.compile(expr, re.VERBOSE)
+
+COMMENT_RE = compile_re("/\*([^*]+|\*[^/])*\*/")
+STRUCT_DEF_RE = compile_re("struct\s+_(TOKEN)\s*{([^}]*)}")
+
+# This certainly can't handle all type declarations, but it only
+# needs to handle the ones we use in the test cases
+FIELD_RE = compile_re("^(?:const\s+)?TOKEN(?:[\s*]+)(TOKEN)\s*;$");
+
+
+input_f = open(sys.argv[1])
+input = input_f.read()
+input_f.close()
+
+# Strip comments
+input = COMMENT_RE.sub("", input)
+
+symbols = []
+symbol_fields = {}
+
+for m in STRUCT_DEF_RE.finditer(input):
+    symbol = m.group(1)
+
+    fields = []
+
+    body = m.group(2)
+    for line in re.split("\n|\r\n", body):
+        line = line.strip()
+        if line == "":
+            continue
+        n = FIELD_RE.match(line)
+        if not n:
+            print sys.stderr, "Can't parse structure line '%s'" % line
+            sys.exit(1)
+        fields.append(n.group(1))
+
+    symbols.append(symbol)
+    symbol_fields[symbol] = fields
+
+# Sort for convenience
+symbols.sort()
+
+output({}, r'''
+| /* GENERATED FILE. DO NOT EDIT. See gen-gitestoffsets */
+|
+|#include <errno.h>
+|#include <stdio.h>
+|#include <string.h>
+|#include <glib.h>
+|#include <girepository.h>
+|#include "offsets.h"
+|
+|static GIRepository *repository;
+|static const char *namespace = "offsets";
+|static const char *version = "1.0";
+|
+|static void
+|print_field_offset(FILE         *outfile,
+|                   GIStructInfo *struct_info,
+|                   const gchar  *name)
+|{
+|   gint i;
+|   gint n_fields = g_struct_info_get_n_fields (struct_info);
+|   for (i = 0; i < n_fields; i++)
+|     {
+|       GIFieldInfo *field_info = g_struct_info_get_field (struct_info, i);
+|       const char *field_name = g_base_info_get_name ((GIBaseInfo *)field_info);
+|       if (strcmp (field_name, name) == 0)
+|         {
+|           fprintf (outfile, "%%s %%d\n", name, g_field_info_get_offset (field_info));
+|           g_base_info_unref ((GIBaseInfo *)field_info);
+|           return;
+|         }
+|
+|       g_base_info_unref ((GIBaseInfo *)field_info);
+|     }
+|
+|   g_error("Can't find field '%%s.%%s' in introspection information",
+|           g_base_info_get_name ((GIBaseInfo *)struct_info), name);
+|}
+|
+''')
+
+for symbol in symbols:
+    fields = symbol_fields[symbol]
+
+    output({'symbol' : symbol}, r'''
+|static void
+|compiled_%(symbol)s (FILE *outfile)
+|{
+|  fprintf (outfile, "%(symbol)s:\n");
+|
+           ''')
+
+    for field in fields:
+        output({ 'field' : field, 'symbol' : symbol }, r'''
+|  fprintf (outfile, "%%s %%ld\n", "%(field)s", G_STRUCT_OFFSET(%(symbol)s, %(field)s));
+               ''')
+
+    output({}, r'''
+|
+|  fprintf (outfile, "\n");
+|}
+|
+           ''')
+
+    if not symbol.startswith("Offsets"):
+        print >> sys.stderr, "Symbol '%s' doesn't start with Offsets" % symbol
+    bare_symbol = symbol[len("Offsets"):]
+
+
+    output({'symbol' : symbol, 'bare_symbol' : bare_symbol}, r'''
+|static void
+|introspected_%(symbol)s (FILE *outfile)
+|{
+|  GIStructInfo *struct_info = (GIStructInfo *)g_irepository_find_by_name(repository, namespace,
+|                                                                         "%(bare_symbol)s");
+|  if (!struct_info)
+|     g_error ("Can't find GIStructInfo for '%(symbol)s'");
+|
+|  fprintf (outfile, "%(symbol)s:\n");
+|
+           ''')
+    for field in fields:
+        output({'field' : field}, '''
+|  print_field_offset(outfile, struct_info, "%(field)s");
+               ''')
+
+    output({}, r'''
+|
+|  fprintf (outfile, "\n");
+|
+|  g_base_info_unref ((GIBaseInfo *)struct_info);
+|}
+           ''')
+
+output({}, r'''
+|
+|int main(int argc, char **argv)
+|{
+|  GError *error = NULL;
+|  FILE *outfile;
+|
+|  if (argc != 3)
+|    g_error ("Usage: gitestoffsets COMPILED_OFFSETS_FILE INTROSPECTED_OFFSETS_FILE");
+|
+|  g_type_init ();
+|
+|  repository = g_irepository_get_default ();
+|  if (!g_irepository_require (repository, namespace, version, 0, &error))
+|     g_error ("Failed to load %%s-%%s.typelib: %%s", namespace, version, error->message);
+|
+|  outfile = fopen (argv[1], "w");
+|  if (!outfile)
+|    g_error ("Cannot open '%%s': %%s'", argv[1], g_strerror(errno));
+|
+''')
+
+for symbol in symbols:
+    output({'symbol' : symbol}, '''
+|  compiled_%(symbol)s (outfile);
+   ''')
+
+output({}, '''
+|
+|  fclose (outfile);
+|
+|  outfile = fopen (argv[2], "w");
+|  if (!outfile)
+|    g_error ("Cannot open '%%s': %%s'", argv[1], g_strerror(errno));
+|
+''')
+
+
+for symbol in symbols:
+    output({'symbol' : symbol}, '''
+|  introspected_%(symbol)s (outfile);
+''')
+
+output({}, r'''
+|
+|  fclose (outfile);
+|
+|  return 0;
+}
+''')