[Xcb] [PATCH v2] c_client.py: avoid field name clash with C++ 'explicit' keyword
Klemens Baum
klemensbaum at gmail.com
Sun Dec 27 13:06:27 PST 2015
The generated code was causing compilation errors when xcb/xkb.h
is included in a C++ code base.
To avoid breaking the API for C users, the unprefixed field names
are provided as alternative names via an anonymous union.
For existing C++ users, the relevant header file would not have
compiled in the first place, so breaking the API is justified.
If they were abusing the preprocessor to modify the header,
it's their own fault for not resolving the issue upstream.
This resolves bug #74080.
---
src/c_client.py | 74 ++++++++++++++++++++++++++++++++++++++-------------------
1 file changed, 50 insertions(+), 24 deletions(-)
diff --git a/src/c_client.py b/src/c_client.py
index c38b434..343e9d6 100644
--- a/src/c_client.py
+++ b/src/c_client.py
@@ -17,9 +17,10 @@ _cname_special_cases = {'DECnet':'decnet'}
_extension_special_cases = ['XPrint', 'XCMisc', 'BigRequests']
-_cplusplus_annoyances = {'class' : '_class',
- 'new' : '_new',
- 'delete': '_delete'}
+_cplusplus_annoyances = {'class' : '_class',
+ 'new' : '_new',
+ 'delete' : '_delete',
+ 'explicit': '_explicit'}
_c_keywords = {'default' : '_default'}
_hlines = []
@@ -192,16 +193,21 @@ def _n_item(str):
name_parts = [match.group(0) for match in split]
return '_'.join(name_parts)
-def _cpp(str):
+def _c_sanitize(str):
+ '''
+ Checks for certain C reserved words and fixes them.
+ '''
+ if str in _c_keywords:
+ return _c_keywords[str]
+ return str
+
+def _cpp_sanitize(str):
'''
Checks for certain C++ reserved words and fixes them.
'''
if str in _cplusplus_annoyances:
return _cplusplus_annoyances[str]
- elif str in _c_keywords:
- return _c_keywords[str]
- else:
- return str
+ return _c_sanitize(str)
def _ext(str):
'''
@@ -297,6 +303,14 @@ def c_open(self):
_h('')
_h('#ifdef __cplusplus')
_h('extern "C" {')
+ _h('#define XCB_ALTERNATIVE_NAMES(type, c_name, cpp_name) \\')
+ _h(' type cpp_name')
+ _h('#else')
+ _h('#define XCB_ALTERNATIVE_NAMES(type, c_name, cpp_name) \\')
+ _h(' union { \\')
+ _h(' type c_name; \\')
+ _h(' type cpp_name; \\')
+ _h(' }')
_h('#endif')
if _ns.is_ext:
@@ -324,6 +338,9 @@ def c_close(self):
_h('#endif')
_h('')
+ _h('#undef XCB_ALTERNATIVE_NAMES')
+
+ _h('')
_h('#endif')
_h('')
_h('/**')
@@ -425,7 +442,8 @@ def _c_type_setup(self, name, postfix):
self.c_need_serialize = True
self.c_container = 'struct'
for bitcase in self.bitcases:
- bitcase.c_field_name = _cpp(bitcase.field_name)
+ bitcase.c_field_name = _cpp_sanitize(bitcase.field_name)
+ bitcase.c_legacy_field_name = _c_sanitize(bitcase.field_name)
bitcase_name = bitcase.field_type if bitcase.type.has_name else name
_c_type_setup(bitcase.type, bitcase_name, ())
@@ -439,7 +457,8 @@ def _c_type_setup(self, name, postfix):
for field in self.fields:
field.c_field_type = _t(field.field_type)
field.c_field_const_type = ('' if field.type.nmemb == 1 else 'const ') + field.c_field_type
- field.c_field_name = _cpp(field.field_name)
+ field.c_field_name = _cpp_sanitize(field.field_name)
+ field.c_legacy_field_name = _c_sanitize(field.field_name)
field.c_subscript = '[%d]' % field.type.nmemb if (field.type.nmemb and field.type.nmemb > 1) else ''
field.c_pointer = ' ' if field.type.nmemb == 1 else '*'
@@ -580,13 +599,13 @@ def _c_helper_fieldaccess_expr(prefix, field=None):
# (also, their accessor function needs a different arglist
# so this would require special treatment here)
# Therefore: Access as struct member
- prefix_str += last_sep + _cpp(field.field_name)
+ prefix_str += last_sep + _cpp_sanitize(field.field_name)
else:
# Access with the accessor function
prefix_str = field.c_accessor_name + "(" + prefix_str + ")"
else:
# Access as struct member
- prefix_str += last_sep + _cpp(field.field_name)
+ prefix_str += last_sep + _cpp_sanitize(field.field_name)
return prefix_str
@@ -612,7 +631,7 @@ def _c_helper_field_mapping(complex_type, prefix, flat=False):
if f.field_name in all_fields:
raise Exception("field name %s has been registered before" % f.field_name)
- all_fields[f.field_name] = (fname, f)
+ all_fields[f.c_field_name] = (fname, f)
if f.type.is_container and not flat:
if f.type.is_case_or_bitcase and not f.type.has_name:
new_prefix = prefix
@@ -1073,9 +1092,9 @@ def _c_serialize_helper_fields_fixed_size(context, self, field,
raise Exception("type for field '%s' (expression '%s') unkown" %
(field.field_name, _c_accessor_get_expr(field.type.expr)))
- temp_vars.append(' %s xcb_expr_%s = %s;' % (field.type.c_type, _cpp(field.field_name),
+ temp_vars.append(' %s xcb_expr_%s = %s;' % (field.type.c_type, _cpp_sanitize(field.field_name),
_c_accessor_get_expr(field.type.expr, prefix)))
- value += "&xcb_expr_%s;" % _cpp(field.field_name)
+ value += "&xcb_expr_%s;" % _cpp_sanitize(field.field_name)
elif field.type.is_pad:
if field.type.nmemb == 1:
@@ -2054,6 +2073,12 @@ def _c_complex(self, force_packed = False):
struct_fields = []
maxtypelen = 0
+ def _declare_as_pointer(self, field):
+ return not ((field.type.fixed_size() and not self.is_union) or
+ # in case of switch with switch children, don't make the field a pointer
+ # necessary for unserialize to work
+ (self.is_switch and field.type.is_switch))
+
for field in self.fields:
if field.wire and (field.type.fixed_size() or self.is_switch or self.is_union):
struct_fields.append(field)
@@ -2061,20 +2086,21 @@ def _c_complex(self, force_packed = False):
for field in struct_fields:
length = len(field.c_field_type)
# account for '*' pointer_spec
- if not field.type.fixed_size() and not self.is_union:
+ if _declare_as_pointer(self, field):
length += 1
maxtypelen = max(maxtypelen, length)
def _c_complex_field(self, field, space=''):
- if (field.type.fixed_size() or self.is_union or
- # in case of switch with switch children, don't make the field a pointer
- # necessary for unserialize to work
- (self.is_switch and field.type.is_switch)):
- spacing = ' ' * (maxtypelen - len(field.c_field_type))
- _h('%s %s%s %s%s;', space, field.c_field_type, spacing, field.c_field_name, field.c_subscript)
+ if field.c_field_name != field.c_legacy_field_name:
+ pointer = ' *' if _declare_as_pointer(self, field) else ''
+ _h('%s XCB_ALTERNATIVE_NAMES(%s%s, %s, %s);', space, field.c_field_type,
+ pointer, field.c_legacy_field_name, field.c_field_name)
else:
- spacing = ' ' * (maxtypelen - (len(field.c_field_type) + 1))
- _h('%s %s%s *%s%s;', space, field.c_field_type, spacing, field.c_field_name, field.c_subscript)
+ spacing = ' ' * (maxtypelen - len(field.c_field_type))
+ pointer = '*' if _declare_as_pointer(self, field) else ' '
+ _h('%s %s%s%s%s%s;', space, field.c_field_type, spacing, pointer,
+ field.c_field_name, field.c_subscript)
+
if not self.is_switch:
for field in struct_fields:
--
2.6.4
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