Allow a new optional 'Attributes' section to be specified for helper
functions description, e.g.:
* u32 bpf_get_smp_processor_id(void)
* ...
* Return
* ...
* Attributes
* __bpf_fastcall
*
Generated header for the example above:
#ifndef __bpf_fastcall
#if __has_attribute(__bpf_fastcall)
#define __bpf_fastcall __attribute__((bpf_fastcall))
#else
#define __bpf_fastcall
#endif
#endif
...
__bpf_fastcall
static __u32 (* const bpf_get_smp_processor_id)(void) = (void *) 8;
The following rules apply:
- when present, section must follow 'Return' section;
- attribute names are specified on the line following 'Attribute'
keyword;
- attribute names are separated by spaces;
- section ends with an "empty" line (" *\n").
Valid attribute names are recorded in the ATTRS map.
ATTRS maps shortcut attribute name to correct C syntax.
Signed-off-by: Eduard Zingerman <eddyz87@xxxxxxxxx>
---
scripts/bpf_doc.py | 50 ++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 48 insertions(+), 2 deletions(-)
diff --git a/scripts/bpf_doc.py b/scripts/bpf_doc.py
index c55878bddfdd..db50c8d7d112 100755
--- a/scripts/bpf_doc.py
+++ b/scripts/bpf_doc.py
@@ -37,10 +37,11 @@ class APIElement(object):
@desc: textual description of the symbol
@ret: (optional) description of any associated return value
"""
- def __init__(self, proto='', desc='', ret=''):
+ def __init__(self, proto='', desc='', ret='', attrs=[]):
self.proto = proto
self.desc = desc
self.ret = ret
+ self.attrs = attrs
class Helper(APIElement):
@@ -81,6 +82,11 @@ class Helper(APIElement):
return res
+ATTRS = {
+ '__bpf_fastcall': 'bpf_fastcall'
+}
+
+
class HeaderParser(object):
"""
An object used to parse a file in order to extract the documentation of a
@@ -111,7 +117,8 @@ class HeaderParser(object):
proto = self.parse_proto()
desc = self.parse_desc(proto)
ret = self.parse_ret(proto)
- return Helper(proto=proto, desc=desc, ret=ret)
+ attrs = self.parse_attrs(proto)
+ return Helper(proto=proto, desc=desc, ret=ret, attrs=attrs)
def parse_symbol(self):
p = re.compile(r' \* ?(BPF\w+)$')
@@ -192,6 +199,28 @@ class HeaderParser(object):
raise Exception("No return found for " + proto)
return ret
+ def parse_attrs(self, proto):
+ p = re.compile(r' \* ?(?:\t| {5,8})Attributes$')
+ capture = p.match(self.line)
+ if not capture:
+ return []
+ # Expect a single line with mnemonics for attributes separated by spaces
+ self.line = self.reader.readline()
+ p = re.compile(r' \* ?(?:\t| {5,8})(?:\t| {8})(.*)')
+ capture = p.match(self.line)
+ if not capture:
+ raise Exception("Incomplete 'Attributes' section for " + proto)
+ attrs = capture.group(1).split(' ')
+ for attr in attrs:
+ if attr not in ATTRS:
+ raise Exception("Unexpected attribute '" + attr + "' specified for " + proto)
+ self.line = self.reader.readline()
+ if self.line != ' *\n':
+ raise Exception("Expecting empty line after 'Attributes' section for " + proto)
+ # Prepare a line for next self.parse_* to consume
+ self.line = self.reader.readline()
+ return attrs
+
def seek_to(self, target, help_message, discard_lines = 1):
self.reader.seek(0)
offset = self.reader.read().find(target)
@@ -789,6 +818,21 @@ class PrinterHelpers(Printer):
print('%s;' % fwd)
print('')
+ used_attrs = set()
+ for helper in self.elements:
+ for attr in helper.attrs:
+ used_attrs.add(attr)
+ for attr in sorted(used_attrs):
+ print('#ifndef %s' % attr)
+ print('#if __has_attribute(%s)' % ATTRS[attr])
+ print('#define %s __attribute__((%s))' % (attr, ATTRS[attr]))
+ print('#else')
+ print('#define %s' % attr)
+ print('#endif')
+ print('#endif')
+ if used_attrs:
+ print('')
+
def print_footer(self):
footer = ''
print(footer)
@@ -827,6 +871,8 @@ class PrinterHelpers(Printer):
print(' *{}{}'.format(' \t' if line else '', line))
print(' */')
+ if helper.attrs:
+ print(" ".join(helper.attrs))
print('static %s %s(* const %s)(' % (self.map_type(proto['ret_type']),
proto['ret_star'], proto['name']), end='')
comma = ''
--
2.46.0
