| Class | RDoc::C_Parser |
| In: |
parsers/parse_c.rb
|
| Parent: | Object |
We attempt to parse C extension files. Basically we look for the standard patterns that you find in extensions: rb_define_class, rb_define_method and so on. We also try to find the corresponding C source for the methods and extract comments, but if we fail we don‘t worry too much.
The comments associated with a Ruby method are extracted from the C comment block associated with the routine that implements that method, that is to say the method whose name is given in the rb_define_method call. For example, you might write:
/*
* Returns a new array that is a one-dimensional flattening of this
* array (recursively). That is, for every element that is an array,
* extract its elements into the new array.
*
* s = [ 1, 2, 3 ] #=> [1, 2, 3]
* t = [ 4, 5, 6, [7, 8] ] #=> [4, 5, 6, [7, 8]]
* a = [ s, t, 9, 10 ] #=> [[1, 2, 3], [4, 5, 6, [7, 8]], 9, 10]
* a.flatten #=> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
*/
static VALUE
rb_ary_flatten(ary)
VALUE ary;
{
ary = rb_obj_dup(ary);
rb_ary_flatten_bang(ary);
return ary;
}
...
void
Init_Array()
{
...
rb_define_method(rb_cArray, "flatten", rb_ary_flatten, 0);
Here RDoc will determine from the rb_define_method line that there‘s a method called "flatten" in class Array, and will look for the implementation in the method rb_ary_flatten. It will then use the comment from that method in the HTML output. This method must be in the same source file as the rb_define_method.
C classes can be diagramed (see /tc/dl/ruby/ruby/error.c), and RDoc integrates C and Ruby source into one tree
The comment blocks may include special direcives:
In additon, RDoc assumes by default that the C method implementing a Ruby function is in the same source file as the rb_define_method call. If this isn‘t the case, add the comment
rb_define_method(....); // in: filename
As an example, we might have an extension that defines multiple classes in its Init_xxx method. We could document them using
/*
* Document-class: MyClass
*
* Encapsulate the writing and reading of the configuration
* file. ...
*/
/*
* Document-method: read_value
*
* call-seq:
* cfg.read_value(key) -> value
* cfg.read_value(key} { |key| } -> value
*
* Return the value corresponding to +key+ from the configuration.
* In the second form, if the key isn't found, invoke the
* block and return its value.
*/
prepare to parse a C file
# File parsers/parse_c.rb, line 178
178: def initialize(top_level, file_name, body, options, stats)
179: @known_classes = KNOWN_CLASSES.dup
180: @options = options
181: @body = handle_tab_width(handle_ifdefs_in(body))
182: @stats = stats
183: @top_level = top_level
184: @classes = Hash.new
185: @file_dir = File.dirname(file_name)
186: @progress = $stderr unless @options.quiet
187: end
# File parsers/parse_c.rb, line 457
457: def do_aliases
458: @body.scan(%r{rb_define_alias\s*\(\s*(\w+),\s*"([^"]+)",\s*"([^"]+)"\s*\)}m) do
459: |var_name, new_name, old_name|
460: @stats.num_methods += 1
461: class_name = @known_classes[var_name] || var_name
462: class_obj = find_class(var_name, class_name)
463:
464: class_obj.add_alias(Alias.new("", old_name, new_name, ""))
465: end
466: end
# File parsers/parse_c.rb, line 320
320: def do_classes
321: @body.scan(/(\w+)\s* = \s*rb_define_module\s*\(\s*"(\w+)"\s*\)/mx) do
322: |var_name, class_name|
323: handle_class_module(var_name, "module", class_name, nil, nil)
324: end
325:
326: # The '.' lets us handle SWIG-generated files
327: @body.scan(/([\w\.]+)\s* = \s*rb_define_class\s*
328: \(
329: \s*"(\w+)",
330: \s*(\w+)\s*
331: \)/mx) do
332:
333: |var_name, class_name, parent|
334: handle_class_module(var_name, "class", class_name, parent, nil)
335: end
336:
337: @body.scan(/(\w+)\s*=\s*boot_defclass\s*\(\s*"(\w+?)",\s*(\w+?)\s*\)/) do
338: |var_name, class_name, parent|
339: parent = nil if parent == "0"
340: handle_class_module(var_name, "class", class_name, parent, nil)
341: end
342:
343: @body.scan(/(\w+)\s* = \s*rb_define_module_under\s*
344: \(
345: \s*(\w+),
346: \s*"(\w+)"
347: \s*\)/mx) do
348:
349: |var_name, in_module, class_name|
350: handle_class_module(var_name, "module", class_name, nil, in_module)
351: end
352:
353: @body.scan(/([\w\.]+)\s* = \s*rb_define_class_under\s*
354: \(
355: \s*(\w+),
356: \s*"(\w+)",
357: \s*(\w+)\s*
358: \s*\)/mx) do
359:
360: |var_name, in_module, class_name, parent|
361: handle_class_module(var_name, "class", class_name, parent, in_module)
362: end
363:
364: end
# File parsers/parse_c.rb, line 368
368: def do_constants
369: @body.scan(%r{\Wrb_define_
370: (
371: variable |
372: readonly_variable |
373: const |
374: global_const |
375: )
376: \s*\(
377: (?:\s*(\w+),)?
378: \s*"(\w+)",
379: \s*(.*?)\s*\)\s*;
380: }xm) do
381:
382: |type, var_name, const_name, definition|
383: var_name = "rb_cObject" if !var_name or var_name == "rb_mKernel"
384: handle_constants(type, var_name, const_name, definition)
385: end
386: end
Look for includes of the form:
rb_include_module(rb_cArray, rb_mEnumerable);
# File parsers/parse_c.rb, line 723
723: def do_includes
724: @body.scan(/rb_include_module\s*\(\s*(\w+?),\s*(\w+?)\s*\)/) do |c,m|
725: if cls = @classes[c]
726: m = @known_classes[m] || m
727: cls.add_include(Include.new(m, ""))
728: end
729: end
730: end
# File parsers/parse_c.rb, line 390
390: def do_methods
391:
392: @body.scan(%r{rb_define_
393: (
394: singleton_method |
395: method |
396: module_function |
397: private_method
398: )
399: \s*\(\s*([\w\.]+),
400: \s*"([^"]+)",
401: \s*(?:RUBY_METHOD_FUNC\(|VALUEFUNC\()?(\w+)\)?,
402: \s*(-?\w+)\s*\)
403: (?:;\s*/[*/]\s+in\s+(\w+?\.[cy]))?
404: }xm) do
405: |type, var_name, meth_name, meth_body, param_count, source_file|
406: #"
407:
408: # Ignore top-object and weird struct.c dynamic stuff
409: next if var_name == "ruby_top_self"
410: next if var_name == "nstr"
411: next if var_name == "envtbl"
412: next if var_name == "argf" # it'd be nice to handle this one
413:
414: var_name = "rb_cObject" if var_name == "rb_mKernel"
415: handle_method(type, var_name, meth_name,
416: meth_body, param_count, source_file)
417: end
418:
419: @body.scan(%r{rb_define_attr\(
420: \s*([\w\.]+),
421: \s*"([^"]+)",
422: \s*(\d+),
423: \s*(\d+)\s*\);
424: }xm) do #"
425: |var_name, attr_name, attr_reader, attr_writer|
426:
427: #var_name = "rb_cObject" if var_name == "rb_mKernel"
428: handle_attr(var_name, attr_name,
429: attr_reader.to_i != 0,
430: attr_writer.to_i != 0)
431: end
432:
433: @body.scan(%r{rb_define_global_function\s*\(
434: \s*"([^"]+)",
435: \s*(?:RUBY_METHOD_FUNC\(|VALUEFUNC\()?(\w+)\)?,
436: \s*(-?\w+)\s*\)
437: (?:;\s*/[*/]\s+in\s+(\w+?\.[cy]))?
438: }xm) do #"
439: |meth_name, meth_body, param_count, source_file|
440: handle_method("method", "rb_mKernel", meth_name,
441: meth_body, param_count, source_file)
442: end
443:
444: @body.scan(/define_filetest_function\s*\(
445: \s*"([^"]+)",
446: \s*(?:RUBY_METHOD_FUNC\(|VALUEFUNC\()?(\w+)\)?,
447: \s*(-?\w+)\s*\)/xm) do #"
448: |meth_name, meth_body, param_count|
449:
450: handle_method("method", "rb_mFileTest", meth_name, meth_body, param_count)
451: handle_method("singleton_method", "rb_cFile", meth_name, meth_body, param_count)
452: end
453: end
# File parsers/parse_c.rb, line 568
568: def find_attr_comment(attr_name)
569: if @body =~ %r{((?>/\*.*?\*/\s+))
570: rb_define_attr\((?:\s*(\w+),)?\s*"#{attr_name}"\s*,.*?\)\s*;}xmi
571: $1
572: elsif @body =~ %r{Document-attr:\s#{attr_name}\s*?\n((?>.*?\*/))}m
573: $1
574: else
575: ''
576: end
577: end
Find the C code corresponding to a Ruby method
# File parsers/parse_c.rb, line 628
628: def find_body(meth_name, meth_obj, body, quiet = false)
629: case body
630: when %r"((?>/\*.*?\*/\s*))(?:static\s+)?VALUE\s+#{meth_name}
631: \s*(\([^)]*\))\s*\{.*?^\}"xm
632: comment, params = $1, $2
633: body_text = $&
634:
635: remove_private_comments(comment) if comment
636:
637: # see if we can find the whole body
638:
639: re = Regexp.escape(body_text) + '[^(]*^\{.*?^\}'
640: if Regexp.new(re, Regexp::MULTILINE).match(body)
641: body_text = $&
642: end
643:
644: # The comment block may have been overridden with a
645: # 'Document-method' block. This happens in the interpreter
646: # when multiple methods are vectored through to the same
647: # C method but those methods are logically distinct (for
648: # example Kernel.hash and Kernel.object_id share the same
649: # implementation
650:
651: override_comment = find_override_comment(meth_obj.name)
652: comment = override_comment if override_comment
653:
654: find_modifiers(comment, meth_obj) if comment
655:
656: # meth_obj.params = params
657: meth_obj.start_collecting_tokens
658: meth_obj.add_token(RubyToken::Token.new(1,1).set_text(body_text))
659: meth_obj.comment = mangle_comment(comment)
660: when %r{((?>/\*.*?\*/\s*))^\s*\#\s*define\s+#{meth_name}\s+(\w+)}m
661: comment = $1
662: find_body($2, meth_obj, body, true)
663: find_modifiers(comment, meth_obj)
664: meth_obj.comment = mangle_comment(comment) + meth_obj.comment
665: when %r{^\s*\#\s*define\s+#{meth_name}\s+(\w+)}m
666: unless find_body($1, meth_obj, body, true)
667: warn "No definition for #{meth_name}" unless quiet
668: return false
669: end
670: else
671:
672: # No body, but might still have an override comment
673: comment = find_override_comment(meth_obj.name)
674:
675: if comment
676: find_modifiers(comment, meth_obj)
677: meth_obj.comment = mangle_comment(comment)
678: else
679: warn "No definition for #{meth_name}" unless quiet
680: return false
681: end
682: end
683: true
684: end
# File parsers/parse_c.rb, line 742
742: def find_class(raw_name, name)
743: unless @classes[raw_name]
744: if raw_name =~ /^rb_m/
745: @classes[raw_name] = @top_level.add_module(NormalModule, name)
746: else
747: @classes[raw_name] = @top_level.add_class(NormalClass, name, nil)
748: end
749: end
750: @classes[raw_name]
751: end
Look for class or module documentation above Init_+class_name+(void), in a Document-class class_name (or module) comment or above an rb_define_class (or module). If a comment is supplied above a matching Init_ and a rb_define_class the Init_ comment is used.
/*
* This is a comment for Foo
*/
Init_Foo(void) {
VALUE cFoo = rb_define_class("Foo", rb_cObject);
}
/*
* Document-class: Foo
* This is a comment for Foo
*/
Init_foo(void) {
VALUE cFoo = rb_define_class("Foo", rb_cObject);
}
/*
* This is a comment for Foo
*/
VALUE cFoo = rb_define_class("Foo", rb_cObject);
# File parsers/parse_c.rb, line 295
295: def find_class_comment(class_name, class_meth)
296: comment = nil
297: if @body =~ %r{((?>/\*.*?\*/\s+))
298: (static\s+)?void\s+Init_#{class_name}\s*(?:_\(\s*)?\(\s*(?:void\s*)\)}xmi
299: comment = $1
300: elsif @body =~ %r{Document-(class|module):\s#{class_name}\s*?\n((?>.*?\*/))}m
301: comment = $2
302: else
303: if @body =~ /rb_define_(class|module)/m then
304: class_name = class_name.split("::").last
305: comments = []
306: @body.split(/(\/\*.*?\*\/)\s*?\n/m).each_with_index do |chunk, index|
307: comments[index] = chunk
308: if chunk =~ /rb_define_(class|module).*?"(#{class_name})"/m then
309: comment = comments[index-1]
310: break
311: end
312: end
313: end
314: end
315: class_meth.comment = mangle_comment(comment) if comment
316: end
Finds a comment matching type and const_name either above the comment or in the matching Document- section.
# File parsers/parse_c.rb, line 525
525: def find_const_comment(type, const_name)
526: if @body =~ %r{((?>^\s*/\*.*?\*/\s+))
527: rb_define_#{type}\((?:\s*(\w+),)?\s*"#{const_name}"\s*,.*?\)\s*;}xmi
528: $1
529: elsif @body =~ %r{Document-(?:const|global|variable):\s#{const_name}\s*?\n((?>.*?\*/))}m
530: $1
531: else
532: ''
533: end
534: end
If the comment block contains a section that looks like:
use it for the parameters.
# File parsers/parse_c.rb, line 696
696: def find_modifiers(comment, meth_obj)
697: if comment.sub!(/:nodoc:\s*^\s*\*?\s*$/m, '') or
698: comment.sub!(/\A\/\*\s*:nodoc:\s*\*\/\Z/, '')
699: meth_obj.document_self = false
700: end
701: if comment.sub!(/call-seq:(.*?)^\s*\*?\s*$/m, '') or
702: comment.sub!(/\A\/\*\s*call-seq:(.*?)\*\/\Z/, '')
703: seq = $1
704: seq.gsub!(/^\s*\*\s*/, '')
705: meth_obj.call_seq = seq
706: end
707: end
# File parsers/parse_c.rb, line 711
711: def find_override_comment(meth_name)
712: name = Regexp.escape(meth_name)
713: if @body =~ %r{Document-method:\s#{name}\s*?\n((?>.*?\*/))}m
714: $1
715: end
716: end
# File parsers/parse_c.rb, line 538
538: def handle_attr(var_name, attr_name, reader, writer)
539: rw = ''
540: if reader
541: #@stats.num_methods += 1
542: rw << 'R'
543: end
544: if writer
545: #@stats.num_methods += 1
546: rw << 'W'
547: end
548:
549: class_name = @known_classes[var_name]
550:
551: return unless class_name
552:
553: class_obj = find_class(var_name, class_name)
554:
555: if class_obj
556: comment = find_attr_comment(attr_name)
557: unless comment.empty?
558: comment = mangle_comment(comment)
559: end
560: att = Attr.new('', attr_name, rw, comment)
561: class_obj.add_attribute(att)
562: end
563:
564: end
# File parsers/parse_c.rb, line 231
231: def handle_class_module(var_name, class_mod, class_name, parent, in_module)
232: progress(class_mod[0, 1])
233:
234: parent_name = @known_classes[parent] || parent
235:
236: if in_module
237: enclosure = @classes[in_module] || @@enclosure_classes[in_module]
238: unless enclosure
239: if enclosure = @known_classes[in_module]
240: handle_class_module(in_module, (/^rb_m/ =~ in_module ? "module" : "class"),
241: enclosure, nil, nil)
242: enclosure = @classes[in_module]
243: end
244: end
245: unless enclosure
246: warn("Enclosing class/module '#{in_module}' for " +
247: "#{class_mod} #{class_name} not known")
248: return
249: end
250: else
251: enclosure = @top_level
252: end
253:
254: if class_mod == "class"
255: cm = enclosure.add_class(NormalClass, class_name, parent_name)
256: @stats.num_classes += 1
257: else
258: cm = enclosure.add_module(NormalModule, class_name)
259: @stats.num_modules += 1
260: end
261: cm.record_location(enclosure.toplevel)
262:
263: find_class_comment(cm.full_name, cm)
264: @classes[var_name] = cm
265: @@enclosure_classes[var_name] = cm
266: @known_classes[var_name] = cm.full_name
267: end
Adds constant comments. By providing some_value: at the start ofthe comment you can override the C value of the comment to give a friendly definition.
/* 300: The perfect score in bowling */ rb_define_const(cFoo, "PERFECT", INT2FIX(300);
Will override +INT2FIX(300)+ with the value 300 in the output RDoc. Values may include quotes and escaped colons (\:).
# File parsers/parse_c.rb, line 479
479: def handle_constants(type, var_name, const_name, definition)
480: #@stats.num_constants += 1
481: class_name = @known_classes[var_name]
482:
483: return unless class_name
484:
485: class_obj = find_class(var_name, class_name)
486:
487: unless class_obj
488: warn("Enclosing class/module '#{const_name}' for not known")
489: return
490: end
491:
492: comment = find_const_comment(type, const_name)
493:
494: # In the case of rb_define_const, the definition and comment are in
495: # "/* definition: comment */" form. The literal ':' and '\' characters
496: # can be escaped with a backslash.
497: if type.downcase == 'const' then
498: elements = mangle_comment(comment).split(':')
499: if elements.nil? or elements.empty? then
500: con = Constant.new(const_name, definition, mangle_comment(comment))
501: else
502: new_definition = elements[0..-2].join(':')
503: if new_definition.empty? then # Default to literal C definition
504: new_definition = definition
505: else
506: new_definition.gsub!("\:", ":")
507: new_definition.gsub!("\\", '\\')
508: end
509: new_definition.sub!(/\A(\s+)/, '')
510: new_comment = $1.nil? ? elements.last : "#{$1}#{elements.last.lstrip}"
511: con = Constant.new(const_name, new_definition,
512: mangle_comment(new_comment))
513: end
514: else
515: con = Constant.new(const_name, definition, mangle_comment(comment))
516: end
517:
518: class_obj.add_constant(con)
519: end
Removes ifdefs that would otherwise confuse us
# File parsers/parse_c.rb, line 768
768: def handle_ifdefs_in(body)
769: body.gsub(/^#ifdef HAVE_PROTOTYPES.*?#else.*?\n(.*?)#endif.*?\n/m, '\1')
770: end
# File parsers/parse_c.rb, line 581
581: def handle_method(type, var_name, meth_name,
582: meth_body, param_count, source_file = nil)
583: progress(".")
584:
585: @stats.num_methods += 1
586: class_name = @known_classes[var_name]
587:
588: return unless class_name
589:
590: class_obj = find_class(var_name, class_name)
591:
592: if class_obj
593: if meth_name == "initialize"
594: meth_name = "new"
595: type = "singleton_method"
596: end
597: meth_obj = AnyMethod.new("", meth_name)
598: meth_obj.singleton =
599: %w{singleton_method module_function}.include?(type)
600:
601: p_count = (Integer(param_count) rescue -1)
602:
603: if p_count < 0
604: meth_obj.params = "(...)"
605: elsif p_count == 0
606: meth_obj.params = "()"
607: else
608: meth_obj.params = "(" +
609: (1..p_count).map{|i| "p#{i}"}.join(", ") +
610: ")"
611: end
612:
613: if source_file
614: file_name = File.join(@file_dir, source_file)
615: body = (@@known_bodies[source_file] ||= File.read(file_name))
616: else
617: body = @body
618: end
619: if find_body(meth_body, meth_obj, body) and meth_obj.document_self
620: class_obj.add_method(meth_obj)
621: end
622: end
623: end
# File parsers/parse_c.rb, line 753
753: def handle_tab_width(body)
754: if /\t/ =~ body
755: tab_width = @options.tab_width
756: body.split(/\n/).map do |line|
757: 1 while line.gsub!(/\t+/) { ' ' * (tab_width*$&.length - $`.length % tab_width)} && $~ #`
758: line
759: end .join("\n")
760: else
761: body
762: end
763: end
Remove the /*’s and leading asterisks from C comments
# File parsers/parse_c.rb, line 735
735: def mangle_comment(comment)
736: comment.sub!(%r{/\*+}) { " " * $&.length }
737: comment.sub!(%r{\*+/}) { " " * $&.length }
738: comment.gsub!(/^[ \t]*\*/m) { " " * $&.length }
739: comment
740: end
# File parsers/parse_c.rb, line 205
205: def progress(char)
206: unless @options.quiet
207: @progress.print(char)
208: @progress.flush
209: end
210: end
removes lines that are commented out that might otherwise get picked up when scanning for classes and methods
# File parsers/parse_c.rb, line 227
227: def remove_commented_out_lines
228: @body.gsub!(%r{//.*rb_define_}, '//')
229: end
# File parsers/parse_c.rb, line 218
218: def remove_private_comments(comment)
219: comment.gsub!(/\/?\*--(.*?)\/?\*\+\+/m, '')
220: comment.sub!(/\/?\*--.*/m, '')
221: end