Step into OpenSSL code using XCode 4.3.2 - xcode

I found this project on the internet: https://github.com/x2on/OpenSSL-for-iPhone.
It has a demo app which calculates MD5 values and takes text input from an editbox. Within the demo app I can step into the OpenSSL code which calculates the MD5 value.
I am using XCode 4.3.2. I have a project which also uses OpenSSL. Within the project something goes wrong with the SSL handshake (this code is executed within OpenSSL).
Though I have built the libraries (libcrypto.a and libssl.a) using the build script from "x2on" and added these libraries to my project I am unable to step into calls to OpenSSL methods from within my own project.
Also I could not discover any relevant setting which is present in the demo app (from "x2on") when I compare the settings with my own app. If I try to step into the OpenSSL call, then execution just moves on to the next line (I do not get into .asm code and also not in the OpenSSL code). Also if I use the right mouse button and choose "Jump to Definition" it brings me to the OpenSSL header file instead of the implementation (.c).
Could somebody give some hints here? How is "stepping into" supposed to work in general? Do the libraries (.a) contains a reference to the location of the source code? Where can you set the search path for source code in XCode? How can you enforce that XCode will re-index the code including the OpenSSL code and make "Jump to Definition" work?
Any help is appreciated as I did discover more people who are or have been struggling with this problem.
ADDITION:
I created a small test app, added libcrypto.a and libssl.a to the Frameworks folder and included the path to the header files for OpenSSL into the Build Settings | Header Search Paths. No problem to step into a piece of OpenSSL code/methods ...
However, when I apply the same strategy to my huge project, then it steps over the OpenSSL call instead of stepping into the OpenSSL call ... I heard that each project should reference a static library only once? If the project references a static library multiple times, then would this break the functionality to step into the code of that library ...?
Forgot to add: for the small test app there was no need to indicate the location of the source files for OpenSSL. So my tentative conclusion is that the .a libs contain a reference to the source files for OpenSSL (how could XCode otherwise know the location of the source files?).
To share some further information: both in my huge project and in the test application it is not possible to jump to the source code by selecting "Jump to Definition". So stepping into the code and "Jump to Definition" seem/are unrelated.

Related

Code::Blocks & WxWidgets Matching Release configuration

I am attempting to start a new project in Code:: Blocks (v17.12) using WxWidgets (v3.1.3) on Windows (10).
(For context, I am new to compiling- I'm a script coder trying to branch out. So... don't be afraid to talk to me like I'm an idiot. I'm prepared to accept that possibility.)
I downloaded the official 3.1.3 source, expanded it to "D:\code\wxw"
I successfully compiled it using mingw32-make that came with Code::Blocks-- there is a directory "D:\code\wxw\build\msw\gcc_mswudll" and "D:\code\wxw\lib\gcc_dll", the latter containing .dll files.
So I go into code blocks, and I:
Create New Project -> wxWidgets Project
Select wxWidgets 3.1.x
Project Title "HelloWorld", under D:\code\C++\tinker-- everything else autofilled.
Project details-- my info.
Preferred GUI Builder - None. Application Type - Dialog.
wxWidgets' location: D:\code\wxw
Compiler: GNU GCC
Selected "Create Release Configuration" because that's how it was compiled.
It provides an Output dir of "bin\Release\" and an Objects output dir of "obj\Release\", which I do not change.
Selected use DLL, built as monolithic, and enable Unicode-- the latter matching my compile settings.
When I click next, it tells me "A Matching Release configuration cannot be found in the wxWidgets directory you specified. This means that the Release target of your project will not build."
I've found multiple hits searching on this error message, but they all devolve into discussions of monolithic vs polylithic compiling and critique of other compiler settings and not actually addressing the problem.
EDIT:
Based on http://wiki.codeblocks.org/index.php?title=WxWindowsQuickRef
I used the following settings for compiling. I set them in config.gcc
BUILD=release SHARED=1 MONOLITHIC=1 UNICODE=1 CXXFLAGS=-fno-keep-inline-dllexport
The most important page of the wizard is the 8th page. Based on the settings you gave above, it should look exactly like this:
Also, instead of giving the path on the 6th page, I would define a global variable named wx in codeblocks like this:
Then on the 6th page, you would enter $(#wx) instead of the actual path. This will make using your projects much easier if you ever upgrade the wxWidgets library. You'll only need to change the location in the global variable settings.

Do I need to build LLDB locally to use C++ interface?

I have XCode 5 installed, I can use command-line lldb just fine. Now I want to create my own application that will link with LLDB C++ interface. I tried to search through the XCode package and found no .a archives, no headers. Does this mean I need to build LLDB locally (and go through the signing process)?
it is indeed correct that there are no header files included in the LLDB.framework that comes with Xcode
With that said, you have two possible avenues:
build LLDB from source, as you said, and then use the built ToT to write your app
obtain the headers from our open source repository and put them in the magical location in the Xcode-provided LLDB.framework and that should enable you to link successfully against whatever LLDB you have.
The incantation should be to make an Headers folder in LLDB.framework/Versions/A and copy all the PUBLIC headers from our sources into there (you want LLDB.h, all the SB*.h files and lldb-defines,enumerations,forward,public,types,versioning.h) - then go into LLDB.framework and make a symlink named Headers to Versions/Current/Headers
Just an FYI - the public API (SB*.h) is all that is pretty much supported and guaranteed to be relatively stable. If you start trying to use the private layer (lldb_private::*), you are going to be on your own and breakages might be fairly frequent as the internals of the debugger evolve

Xcode Mistakenly Added Library to Project and I Can't get Rid of it

So I was trying to add some files to my project and double clicked on library and before I know it the whole entire library was being referenced into my project.
At first I thought, okay no big deal I'll just remove the reference, I did that it took some time, I saved afterword all seem fine, I even added some code.
From here I closed my project, come in the next day open the project and the library is in my project indexing itself. I try removing the reference again and it seems to go away, but now some of my work from the day before isn't there however some of it is, so my program can't run. To top things off Xcode crashes, open up my project again and library is still there, can someone help me with this?
From the Apple Developer Website:
http://developer.apple.com/library/ios/technotes/iOSStaticLibraries/Articles/configuration.html#//apple_ref/doc/uid/TP40012554-CH3-SW1
Select the Build Settings tab in your application target editor. Find the “Other Linker Flags” build setting. Add the flag -ObjC to this build setting’s value if it is not already present. This flag will tell the linker to link all Objective-C classes and categories from static libraries into your application, even if the linker can’t tell that they are used. This is needed because Objective-C is a dynamic language and the linker can’t always tell which classes and categories are used by your application code.
So I recommend to see if this has been done in your project settings and if it has then delete the flag in your build settings.

How to organize C source file previously compiled by GCC Make and build them into an Xcode bundle? I have a Duplicate Symbol _main Error

How to build a .bundle from source code?
This might sound like a simple problem but it has been hurdling me for a week...
Here is my problem:
I have a bunch of .c and .h files that are organized in a folder and its sub folders. The source code was written and compiled with gcc make and tested by many other make tools. The source code has some utilities and command line tools and it has more code that serve as library for those utilities and tools. It is the files that serve as libraries that I want to reuse. (By library I don't mean static library or something, I just mean that some .c and .h files in certain subfolders provide functions that can be called by some other .c files. I want to be able to call those functions, too)
Yet my problem is more complex than that: I need to build those .c and .h into a bundle to reuse it. I am not writing my application in C; I am developing in Unity and Unity can only take in .bundle files on Mac OS.
Here is my goal:
Organize the source code folder in a proper way so that I can build them into a bundle in Xcode 4.
Here is where I got stuck:
When building the project I got the following error:
Duplicate symbol _main in
/Users/zeningqu/Library/Developer/Xcode/DerivedData/ccn-cfygrtkrshubpofnfxalwimtyniq/Build/Intermediates/ccn.build/Debug/ccn.build/Objects-normal/i386/ccndsmoketest.o
and
/Users/zeningqu/Library/Developer/Xcode/DerivedData/ccn-cfygrtkrshubpofnfxalwimtyniq/Build/Intermediates/ccn.build/Debug/ccn.build/Objects-normal/i386/ccnd_main.o
for architecture i386
I can relate to this error because I can find lots of main entries in the source code. Most of them are test utilities.
Here is what I tried:
I tried removing all those utility .c files but with no luck. The error is still there. I delete and delete until some files cannot find the definition of the function they are calling. So I had to stop there.
Though I wasn't able to build a bundle I was able to build a C/C++ static library (with an .a extension). After I got the .a file I tried to put it into another Xcode project and tried to build it into a bundle. I could build a bundle in that way, but then I had problem accessing the content of the bundle. How do I call functions defined in a .a static library if that library is hidden in a bundle? I read about Apple's documentation which says:
Note: Some Xcode targets (such as shell tools and static libraries) do
not result in the creation of a bundle or package. This is normal and
there is no need to create bundles specifically for these target
types. The resulting binaries generated for those targets are intended
to be used as is.
(quoted from: https://developer.apple.com/library/mac/#documentation/CoreFoundation/Conceptual/CFBundles/AboutBundles/AboutBundles.html#//apple_ref/doc/uid/10000123i-CH100-SW1)
Here is what I thought about:
I thought about replacing all main with something like main_sth. But the source code was not written by me so I didn't want to modify it. (It just doesn't feel like a proper way of doing things to me...)
I learnt that Xcode has gcc compiler built in. So I guess if gcc can make it, so can Xcode? It's just a wild guess - I am not familiar with Xcode and gcc.
Here is a summary of my questions:
Is there a way to properly organize a pile of code previously compiled and made by gcc make so that they can be built into an Xcode bundle?
Is it meaningful to put a .a library in an Xcode project and build it into a bundle? If it is meaningful, how do I call functions defined in .a after it is built into a bundle?
Is it proper to just replace all main() entries with something else?
Alright I think I have figured out at least one solution to the problem.
The duplicate main error was caused by a bunch of main entries in my source code. When the code was compiled by gcc make, I guess the author defined a sort of compilation order so that duplicate mains won't be an issue. (If you know how to do this, please let me know. I barely know make tools.) But when I just add the entire source code folder into my Xcode project, of course Xcode would complain during linking...
As I was unwilling to modify the source code (because the source code library is not developed by me), I decided to use another strategy to walk around this problem.
If your duplicate main error was reported from your own code, you can stop reading here. But if you are like me, with a bunch of gcc compiled source code and badly need a bundle yet don't know what to do, I may be able to help.
Okay here is what I did:
I set up an empty workspace.
I built a C/C++ static library project.
Import my entire source code folder into the static library project.
Set some header search path for the static library project.
Build the static library project. (Now I have a .a library which I could link against)
I set up another project, with a bundle target.
At the bundle project -> Build Phases -> Link Binary with Libraries, add the .a library that I just built.
At the bundle project -> edit scheme -> Build, add the static library project to the scheme and move it up the list so that it is built prior to my bundle project.
Then add .h files of my library project to my bundle project as references.
After that, add a .c file in my bundle project that basically functions as a wrapper. I picked a function that I want to call in Unity, wrote a wrapper function in the new .c file, and was able to build the bundle.
After several trial and error, I was able to import the bundle into Unity and was able to call the test function from Unity.
I was really excited about this! Though it's not completed yet I think this gives me hope and I am confident I can use the source code now! And the best thing about this solution is that I don't have to modify the library code developed by others. Whenever they update their code, I just update my .a library and that's it!
Though I have listed 11 steps I still feel that there are lots of details that I missed. So here are my references:
I followed this tutorial to build my source code into a static library: http://www.ccnx.org/?post_type=incsub_wiki&p=1315
I followed this blog to link static library against my bundle code and twist build phases and search headers: http://blog.carbonfive.com/2011/04/04/using-open-source-static-libraries-in-xcode-4/
I followed this doc to import my bundle to Unity3D Pro as a plugin: http://unity3d.com/support/documentation/Manual/Plugins.html
I strongly recommend the second reference because that's what solved my problem!
Though the problem is almost solved there are still a few things that I haven't figured out:
I don't know if a wrapper function is at all necessary. I will try this out tomorrow and come back to update.
-- I am coming back to update: the wrapper function is NOT necessary. Just make sure you have all the headers in your bundle project and you will be able to use all the data structures and call functions defined in your headers.
I haven't used NSBundle class though I read a few docs about it. Previously I was thinking about using that class to access my .a library encapsulated in my bundle, but as I found the solution I wrote above, I didn't try the class out.
Lastly, if you have better solution, please don't hesitate to let me know!
I tried to follow the steps in the accepted answer, but had no luck. In the end, I realised step 10 needed to be modified slightly:
Create a dummy.c under (.bundle) project and the dummy.c can just be totally empty.
Remove the setting for the library you want to link inside Link Binary With Libraries
Instead use -Wl,-force_load,$(CONFIGURATION_BUILD_DIR)/libYourLib.a or -all_load to Other Linker Flags
PS: And also can use sub-project instead of workspace. and use Target Dependencies instead of Edit Scheme to achieve the same effect.

Adding OCHamcrest to an IOS Project

The documentation for the project says just add the framework and the linker flags and you are good to go. Hours and hours of wasted time later, I have figured out that that's not true. If you do that, the project does not see the header files. You have to put the framework somewhere were the compiler will find the headers. In my case, that worked when I dropped the framework into /Developer/Library/Frameworks and then told it to recurse in searching that framework directory (do not fiddle around with the headers search directories).
Then the problem I get is that the link fails with the message:
ld: framework not found OCHamcrestIOS
I noticed that the documentation for the project says that it was updated for Xcode 4. I pulled down the binary of the framework after checking out the code and wasting a ton of time unable to build the IOS version of the framework.
The documentation is here.
I also noticed in that documentation that the cocoa instructions tell you to put a copy files phase into the build. I tried that. Didn't change the outcome.
The last time I fell into a sink hole it was because the library was C++ code. Maybe that's still the problem.
Barring a rapid solution here, I am going to go back to using STAsserts, as sickening as that prospect is, this is far, far worse.
Update: reinstalled Xcode. Still doesn't work. There are cheap ways to make this work, like add the header files to the project. Did a blog post about this that brought out a person with the same experience.
I use a number of frameworks in my projects. Some from other people and some are mine. Looking at the documentation I would suggest that the copy phase stuff is not for iOS development. So I would not do that. I downloaded the latest zip from https://github.com/jonreid/OCHamcrest and it appears to contain a ready to go iOS static library. (Not on my mac so I cannot test to confirm).
Anyway, the way I include static libs is to
Select the project (XCode 4).
Select the target I want to add the library to.
Select the Build phases tab.
Expand Link binary with Libraries.
Click the [+] button to add a framework.
Click the [Add Other ...] button and navigate to the directory containing the <lib>.framework directory and select that.
Thats all. The targets search paths will be updated to include the framework directory and the framework will be listed on the left under the project. Expanding it will show the headers.
The problem you mention sound like a couple of things. Firstly the framework not found sounds like the framework has not been included in the target. When you select the framework in the project list on the left, you should be able to see it's Target Membership displayed on the right. Check it's on for the target you are compiling.
Secondly building frameworks is not a trivial task so don't attempt it unless you have the scripts to do it. I say this because building a iOS static framework means compiling for both simulator and devices, combining the compiled lib files into a universal one, and then storing it and the header in a specific directory strucuture.
The downloaded zip from OCHamcrest though, appears to have the correct OCHamcrestiOS.framework in it. So if you store that directory somewhere and link to it using the steps I've outlined above it should work just fine.
So the solution I adopted for now, after much thrashing around, was to include the framework in the project.
Create a group inside the Xcode project called Third Party.
Link it to a folder called thirdparty.
Go to the Add Files in Xcode and pick the framework.
Drag it over to the dependencies.
Run the tests, they pass!
This is maybe preferable anyway because referencing it in /System/Library/Frameworks would present some versioning issues, and this can be setup very quickly. Furthermore, we have a continuous integration server, and having to get in there and sync versions whenever something changes is not so great.
Thanks for checking it out, Derek.

Resources