== What is rbgccxml?
RbGCCXML allows one to easily parse out and query C++ code. This library uses GCC-XML to parse out
the C++ code into XML, and then libxml-ruby for parsing and querying.
GCC-XML (http://www.gccxml.org) is an application that takes takes the parse tree of g++ and
constructs a very parsable and queryable XML file with all related information. GCC-XML currently
only works with code declarations; there currently are no plans to support code bodies.
Note: For those familiar with pygccxml, the similarities are minimal. Outside of the purpose
of both libraries, rbgccxml was built from scratch to provide a Ruby-esque query API instead of
being a port. However, many thanks to Roman for his work, without which this library would also
not exist.
== Requirements
* libxml-ruby
* gccxml_gem (binary gem, choose proper platform)
== Installation
gem install rbgccxml
RbGCCXML will work on all platforms that GCC-XML supports, which is currently all the major platforms
of Linux, Mac and Windows. If you're on a platform for which there isn't a current gccxml_gem build,
please open a ticket on this project's tracker.
== The Project
For bug reports, patch submissions, project annoucements and downloads, visit RbGCCXML's rubyforge
project page at:
http://www.rubyforge.org/projects/rbplusplus
Feel free to post help request, hints, or general ideas on the forums.
RbGCCXML's source is in a git repository hosted on github:
Project page:
http://github.com/jameskilton/rbgccxml/tree/master
Clone with:
git clone git://github.com/jameskilton/rbgccxml.git
== Usage
=== Parsing
The entry point of an RbGCCXML project is as follows:
# Parse a single header file
RbGCCXML.parse("/path/to/header/file.h")
# Parse out all files that match a given glob
RbGCCXML.parse("/my/headers/**/*.h")
# Parse out a specified set of files"
RbGCCXML.parse(["/path/to/file1.h", "/path/to/file2.h", ...])
# Parse out multiple globs
RbGCCXML.parse(["/my/headers/**/*.h", "/other/headers/*.hpp"])
=== Configuration
As GCC-XML runs on top of GCC, it will need to know about locations of other header files
that may be included by the header files being parsed out. Adding these directories is very easy.
RbGCCXML.parse(..., :includes => *directories)
+directories+ can be a single directory string or an array of directories, just like RbGCCXML.parse.
Also, if there are other CXXFLAGS that need to be added to the command line for GCC-XML to properly
parse the source headers, add those via the :cxxflags option.
RbGCCXML.parse(..., :cxxflags => *flags)
=== Querying By Name
Once the header files have been parsed, RbGCCXML.parse returns a Namespace node that references the
global namespace of "::". From here, all the function, class, etc declarations are easily queryable.
source = RbGCCXML.parse("header.h") #=> <Namespace ...>
Each major C++ part (class, struct, function, method (class functions), argument (of functions, methods, and constructors) have a related query method that can be called in one of two ways:
# Grab all the classes and search from there
source.classes.find(...)
# Or just get a class of a given name, or that matches a regex. These calls are the same as
# source.classes.find(:name => ...)
# Find all classes with the name "ClassName"
source.classes("ClassName")
# Find all classes that match ...Manager
source.classes(/Manager$/)
For finding all classes in a namespace:
source.classes
Or finding all namespaces:
source.namespaces
These queries are also infinitely nestable. To find the class "Math" inside the namespace
"core::utils", you can do:
source.namespaces("core").namespaces("utils").classes("Math")
or as a short-hand form:
source.namespaces("core::utils::Math")
=== Querying with #find
Of course, querying for names is only the tip of the powerful querying that RbGCCXML supports.
What if you wanted to find all methods on a class that return an int value and have three arguments?
This is easy with RbGCCXML:
source.classes("yourclass").methods.find(:returns => :int, :arguments => [nil, nil, nil])
The keys +returns+ and +arguments+ can be used on their own, or together as seen above.
The +arguments+ option must be an array, and if the type of the argument doesn't matter, placing
'nil' in it's place acts as a wildcard. QueryResult#find is also chainable, provided that there
are always more than one result. Otherwise, if there is just one result, only that Node will
be returned and any further chained QueryResult.find methods will fail with "NoMethodError".
For full details on using this method, please see it's documentation at RbGCCXML::QueryResult.
=== The Next Step
To learn more about RbGCCXML, please start looking through the RbGCCXML::Node class; most of the query
API starts there, and following with that head to RbGCCXML::QueryResult.
== Additional Notes
Querying for unsigned types is currently not implemented.
