Get AST Nodes of objective-C class without resolving dependencies - objective-c

I am trying to create a refactoring tool that would allow me to get a syntax tree from an objective-c class so that I can change the structure of the class and output a different version of it that matches my criteria. I am looking at Clang's Libtooling to generate an AST and then take it from there, the issue I'm having is that I need to somehow make sure I provice all paths to all possible headers that are being imported from this source, and that's something I'd like to avoid.
I am wondering if there is a way to generate the AST for a class without having to for example provide paths for the framework containing the class definitions of the properties that the class I wanna refactor hold.
Ideally I would be able to get nodes in raw text of my source file containing things like properties, functions, etc... this way I'd be able to traverse that tree and change its structure to later on regenerate my source in the desired way.

After doing more research I deveoped the understanding that what I was trying to do is not even possible as LibTooling based tools need syntactic and semantic information about a program. This information can be provided via a compile_commands.json file like stated on the documentation:
Clang Tooling needs a compilation database to figure out specific build options for each file. Currently it can create a compilation database from the compile_commands.json file
For Xcode projects, this file can be generated like this:
xcodebuild -project PROJECT_NAME.xcodeproj | xcpretty -r json-compilation-database --output compile_commands.json
you will need to install the xcpretty gem. (gem install xcpretty)
Source: https://clang.llvm.org/docs/HowToSetupToolingForLLVM.html

Related

CMake: How to tell where transitive dependency is coming from?

I'm in the process of rewriting a legacy CMake setup to use modern features like automatic dependency propagation. (i.e. using things like target_include_directories(<target> PUBLIC <dir>) instead of include_directories(<dir>).) Currently, we manually handle all project dependency information by setting a bunch of global directory properties.
In my testing, I've found a few examples where a target in the new build will link to a library that the old build would not. I'm not linking to it explicitly, so I know this is coming from the target's dependencies, but in order to find which one(s) I have to recursively look through all of the project's CMakeLists.txts, following up the dependency hierarchy until I find one that pulls in the library in question. We have dozens of libraries so this is not a trivial process.
Does CMake provide any way to see, for each target, which of its dependencies were added explicitly, and which ones were propagated through transitive dependencies?
It looks like the --graphviz output does show this distinction, so clearly CMake knows the context internally. However, I'd like to write a tree-like script to show dependency information on the command line, and parsing Graphviz files sounds like both a nightmare and a hack.
As far as I can tell, cmake-file-api does not include this information. I thought the codemodel/target/dependencies field might work, but it lists both local and transitive dependencies mixed together. And the backtrace field of each dependency only ties back to the add_executable/add_library call for the current target.
You can parse dot file generated by graphviz and extract details which you want. Below is sample python script to do that.
import pydot
import sys
graph = pydot.graph_from_dot_file(sys.argv[1])
result = {}
for g in graph:
# print(g)
for node in g.get_node_list():
if node.get("label") != None:
result[node.get("label")] = []
for edge in g.get_edges():
result[g.get_node(edge.get_source())[0].get("label")].append(g.get_node(edge.get_destination())[0].get("label"))
for r in result:
print(r+":"+",".join(result[r]))
You can also add this script to run from cmake as custom target, so you can call it from you build system. You can find sample cmake project here

Adding a two new phases to an Xcode framework project

I am building a project on Github written in Objective-C. It resolves MAC addresses down to manufacturer details. The lookup table is currently stored as text file manuf.txt (from the Wireshark project), which is parsed at run-time, which is costly. I would prefer to compile this down to archived objects at build-time, and load that instead.
I would like to amend the build phases such that I:
Build a simple compiler
Run the compiler, parsing manuf.txt and outputting archived objects
Build the framework
Copy the archived objects into the framwork
I am looking for wisdom on how to achieve steps 1 and 2 using Xcode v7.3 as Xcode provides only a Copy Files phase or a Run Script phase. An example of other projects achieving similar goals would be inspiring.
I suspect that what you are asking is possible, but tricky. The reason is that you will need to write a bunch of class files and then dynamically add them to the project.
Firstly you will need to employ a run script phase to run various tools from the command line to parse your file and generate a number of class files from it. I would suggest looking into various templating engines. For example appledoc uses moustache templates to generate API documentation files. You could use the same technique to generate header and implementation files.
Next, rather than generating archived objects an trying to import into a framework. I think you may be better off generating raw source code, adding it to a project and compiling into a framework. Probably simpler in the long run.
To automatically include the generated code I would look into (which means I haven't actually tried this :-) adding a folder reference to the project rather than an Xcode group. Folder references are an option in the 'Add files to ...' dialog.
Folder references refer to a directory and automatically add the entire contents of that directory to a project. So you can use one to point to the directory where you have generated the source code. This is a much better option than trying to manipulate the project or injecting things into an established framework.
I would prefer to parse the file at runtime. After launch you can look for an already existing output, otherwise parse it one time.
However, I have to do something similar at Objective-Cloud. I simply added a run script build phase and put the compiler call into it.

Number of classes in project/workspace

Is there any way to get the number of classes in a project or the complete workspace in Xcode?
A simple way to get a rough idea for a project is by checking the Compile Sources section of the project's Build Phases. The compile sources will list all source files (.m, .swift) and doesn't include any headers.
Assuming roughly one class per source file, this will give you a ballpark idea of how many classes there are in your project at a glance. Note that this doesn't include any embedded projects or frameworks.
You could use cloc which can also be installed via Homebrew: brew install cloc.
Cloc is an open source command line tool for counting lines of code, but it also provides the count of files grouped by file type. The simplest form is cloc <path-to-your-project-dir> but the output can be configured by parameters.
A more complex solution (IMHO too complex) is, using Sonarqube with an Objective C plugin. Sonarqube has a nice interface and many functions, but just for counting classes, it's way to much.

How to reuse Fortran modules without copying source or creating libraries

I'm having trouble understanding if/how to share code among several Fortran projects without building libraries or duplicating source code.
I am using Eclipse/Photran with the Intel compiler (ifort) on a linux system, but I believe I'm having a bigger conceptual problem with modules than with the specific tools.
Here's a simple example: In ~/workspace/cow I have a source directory (src) containing cow.f90 (the PROGRAM) and two modules m_graze and m_moo in m_graze.f90 and m_moo.f90, respectively. This project builds and links properly to create the executable 'cow'. The executable and modules (m_graze.mod and m_moo.mod) are stored in ~/workspace/cow/Debug and object files are stored under ~/workspace/cow/Debug/src
Later, I create ~/workplace/sheep and have src/sheep.f90 as the program and src/m_baa.f90 as the module m_baa. I want to 'use m_graze, only: ruminate' in sheep.f90 to get access to the ruminate() subroutine. I could just copy m_graze.f90 but that could lead to code getting out of sync and doesn't take into account any dependencies m_graze might have. For these reasons, I'd rather leave m_graze in the cow project and compile and link sheep.f90 against it.
If I try to compile the sheep project, I'll get an error like:
error #7002: Error in opening the compiled module file. Check INCLUDE paths. [M_GRAZE]
Under Properties:Project References for sheep, I can select the cow project. Under Properties:Fortran Build:Settings:Intel Compiler:Preprocessor I can add ~/workspace/cow/Debug (location of the module files) to the list of include directories so the compiler now finds the cow modules and compiles sheep.f90. However the linker dies with something like:
Building target: sheep
Invoking: Intel(R) Fortran Linker
ifort -L/home/me/workspace/cow/Debug -o "sheep" ./src/sheep.o
./src/sheep.o: In function `sheep':
/home/me/workspace/sheep/src/sheep.f90:11: undefined reference to `m_graze_mp_ruminate_'
This would normally be solved by adding libraries and library paths to the linker settings except there are no appropriate libraries to link to (this is Fortran, not C.)
The cow project was perfectly capable of compiling and linking together cow.f90, m_graze.f90 and m_moo.f90 into an executable. Yet while the sheep project can compile sheep.f90 and m_baa.f90 and can find the module m_graze.mod, it can't seem to find the symbols for m_graze even though all the requisite information is present on the system for it to do so.
It would seem to be an easy matter of configuration to get the linker portion of ifort to find the missing pieces and put them together but I have no idea what magic words need to be entered where in the Photran UI to make this happen.
I confess an utter lack of interest and competence in C and the C build process and I'd rather avoid the diversion of creating libraries (.a or .so) unless that's the only way to make this work.
Ultimately, I'm looking for a pure Fortran solution to this problem so I can keep a single copy of the source code and don't have to manually maintain a pile of custom Makefiles.
So can this be done?
Apologies if this has already been documented somewhere; Google is only showing me simple build examples, how to create modules, and how to link with existing libraries. There don't seem to be (m)any examples of code reuse with modules that don't involve duplicating source code.
Edit
As respondents have pointed out, the .mod files are necessary but not sufficient; either object code (in the form of m_graze.o) or static or shared libraries must be specified during the linking phase. The .mod files describe the interface to the object code/library but both are necessary to build the final executable.
For an oversimplified toy problem such as this, that's sufficient to answer the question as posed.
In a larger project with more complex dependencies (in my case, 80+KLOC of F90 linking to the MKL version of LAPACK95), the IDE or toolchain may lack sufficient automatic or user-interface facilities to make sharing a single canonical set of source files a viable strategy. The choice seems to be between risking duplicate source files getting out of sync, giving up many of the benefits of an IDE (i.e. avoiding manual creation of make/CMake/SCons files), or, in all likelihood, both. While a revision control system and good code organization can help, it's clear that sharing a single canonical set of source files among projects is far from easy given the current state of Eclipse.
Some background which I suspect you already know: Typically (including ifort) compiling the source code for a Fortran module results in two outputs - a "mod" file that contains a description of the Fortran entities that the module defines that the compiler needs to find whenever it sees a USE statement for the module, and object code for the linker that implements the procedures and variable storage, etc., that the module defines.
Your first error (the one you solved) is because the compiler couldn't find the mod file.
The second error is because the linker hasn't been told about the object code that implements the stuff that was in the source file with the module. I'm not an Eclipse user by any means, but a brute force way of specifying that is just to add the object file (xxxxx/Debug/m_graze.o) as an additional linker option (Fortran Build > Settings, under Intel Fortran Linker > Command Line). (Other tool chains have explicit "additional object file" properties for their link stage - there may well be a better way of doing this for the Intel chain.)
For more involved examples you would typically create a library out of the shared code. That's not really C specific, the only Fortran aspect is that the libraries archive of object code needs to be provided alongside the mod files that the Fortran compiler generates.
Yes the object code must be provided. E.g., when you install libnetcdf-dev in Debian (apt-get install libnetcdf-dev), there is a /usr/include/netcdf.mod file that is included.
You can now use all netcdf routines in your Fortran code. E.g.,
program main
use netcdf
...
end
but you'll have link to the netcdf shared (or static) library, i.e.,
gfortran -I/usr/include/ main.f90 -lnetcdff
However, as user MSB mentioned the mod file can only be used by gfortran that comes with the distribution (apt-get install gfortran). If you want to use any other compiler (even a different version that you may have installed yourself) then you'll have to build netcdf yourself using that particular compiler.
So creating a library is not a bad solution.

.h generated from .h.in?

There are struct definitions in the .h file that my library creates after I build it.. but I cannot find these in the corresponding .h.in. Can somebody tell me how all this works and where it gets the extra info from?
To be specific: I am building pth, the userspace threading library. It has pth_p.h.in, which doesn't contain the struct definition I am looking for, yet when I build the library, a pth_p.h appears and it has the definition I need.
In fact, I have searched every single file in the library before it is built and cannot find where it is generating the struct definition.
Pth uses GNU Autoconf, Automake, and Libtool. By running ./configure you'll be running a shell script which eventually runs m4 to detect the presence of a whole bunch of different system attributes and make changes to a number of files.
It looks like it boils down to ./configure generating Makefile from Makefile.in and then running something via make that triggers the shtool subcommand scpp:
pth_p.h: $(S)pth_p.h.in
$(SHTOOL) scpp -o pth_p.h -t $(S)pth_p.h.in -Dcpp -Cintern -M '==#==' $(HSRCS)
Obscure link, but here's an shtool-scpp manpage, which describes it as:
This command is an additional ANSI C
source file pre-processor for sharing
cpp(1) code segments, internal
variables and internal functions. The
intention for this comes from writing
libraries in ANSI C. Here a common
shared internal header file is usually
used for sharing information between
the library source files.
The operation is to parse special
constructs in files, generate a few
things out of these constructs and
insert them at position mark in tfile
by writing the output to ofile.
Additionally the files are never
touched or modified. Instead the
constructs are removed later by the
cpp(1) phase of the build process. The
only prerequisite is that every file
has a ``"#include ""ofile"""'' at the
top.
.h.in is probably processed within a configure (generated from configure.ac) script, look out for
AC_CONFIG_FILES([thatfile.h])
It replaces variables of the form #VAR# in the .in file with their values.
Edit: Just noticed if I'm right you should retag your question