They differ in how expressive the low level machine type system is.

The [LLVM][1] machine is pretty expressive. The [C--][2] machine on the other hand, puts a lot of responsibility on the language front end. Quoting from the [C-- FAQ][3]:  *&quot;simply, [C--][4] has no high-level types---it does not even distinguish floating-point variables from integer variables. This model gives the front end total control of representation and type system&quot;*


Also visually they look a lot different. [C--][5] looks a lot like C, LLVM looks a lot like assembler.

Pragmatically, LLVM has a lot more momentum right now. It has a JIT compiler, Apple is using it for [3D pipeline things][6] and people are using it to [connect to GCC][10] and all sorts of [weird][7] and [wonderful][10] things. Someone called it &quot;[almost absurdly easy to work with][8]&quot;.

On the other hand [C--][9] is *much* smaller and probably easier to entirely comprehend. (I imagine a normal person with some dedication can fully understand ***all*** aspects of it.)


  [1]: http://llvm.org
  [2]: http://www.cs.tufts.edu/~nr/c--/index.html
  [3]: http://www.cs.tufts.edu/~nr/c--/faq.html
  [4]: http://www.cs.tufts.edu/~nr/c--/index.html
  [5]: http://www.cs.tufts.edu/~nr/c--/index.html
  [6]: http://developer.apple.com/library/mac/#documentation/Performance/Conceptual/OpenCL_MacProgGuide/Introduction/Introduction.html
  [7]: http://en.wikibooks.org/wiki/Aros/Developer/LLVM
  [8]: http://cliffhacks.blogspot.com/2007/03/experimenting-with-llvm.html
  [9]: http://www.cs.tufts.edu/~nr/c--/index.html
  [10]: http://dragonegg.llvm.org/

I have loaded a css file on server so I am having a URL with me. How can i load it in my perl code using JQuery ?

So currently I am hardcoding the css in my mason page which is missing from the page something like this

    JQ.onReady(&#39;show&#39;, function(){
        JQ.addStyles({styles: [&quot;\n\n.ap_classic { border-top:1px solid #ccc;border-left:1px solid #ccc;border-bottom:1px solid #2F2F1D; border-right:1px solid   #2F2F1D;background-color:#EFEDD4;padding:3px; }  .ap_classic .ap_titlebar { color:#86875D;font-size:12px;padding:0 0 3px 0;line-height:1em; }  .ap_classic .ap_close { float:right; }  .ap_classic .ap_content { clear:both;background-color:white;border:1px solid #ACA976;padding:8px;font-size:11px; } &quot;]});
    });
  
I want to avoid hardcoding this css ?
  


How to load CSS using jquery

I have included the camera functionality in my application. I have also launched the app in the market. I got an error message from one of the users that he is getting an error while opening the camera.

I have tested the app on the device on 2.1. The error I got from the user is using nexus one which will mostly run 2.2...Here&#39;s the logcat error that I&#39;ve received...

    java.lang.RuntimeException: setParameters failed
    at android.hardware.Camera.native_setParameters(Native Method)
    at android.hardware.Camera.setParameters(Camera.java:647)
    at com.CameraApp.Preview.surfaceChanged(Preview.java:67)
    at android.view.SurfaceView.updateWindow(SurfaceView.java:538)
    at android.view.SurfaceView.dispatchDraw(SurfaceView.java:339)
    at android.view.ViewGroup.drawChild(ViewGroup.java:1638)
    at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1367)
    at android.view.ViewGroup.drawChild(ViewGroup.java:1638)
    at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1367)
    at android.view.ViewGroup.drawChild(ViewGroup.java:1638)
    at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1367)
    at android.view.View.draw(View.java:6743)
    at android.widget.FrameLayout.draw(FrameLayout.java:352)
    at android.view.ViewGroup.drawChild(ViewGroup.java:1640)
    at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1367)
    at android.view.View.draw(View.java:6743)
    at android.widget.FrameLayout.draw(FrameLayout.java:352)
    at com.android.internal.policy.impl.PhoneWindow$DecorView.draw(PhoneWindow.java:1842)
    at android.view.ViewRoot.draw(ViewRoot.java:1407)
    at android.view.ViewRoot.performTraversals(ViewRoot.java:1163)
    at android.view.ViewRoot.handleMessage(ViewRoot.java:1727)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loop(Looper.java:123)
    at android.app.ActivityThread.main(ActivityThread.java:4627)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:521)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
    at dalvik.system.NativeStart.main(Native Method)


I ran the app on 2.2 emulator also to check it. But it worked fine. Can anyone please tell me why the error is occurring?

Here is the class which I mentioned in the comments:

    class Preview extends SurfaceView implements SurfaceHolder.Callback 
    {
        private static final String TAG = &quot;Preview&quot;;

        SurfaceHolder mHolder;
        public Camera camera;
    
        Preview(Context context) 
        {
            super(context);
        
            // Install a SurfaceHolder.Callback so we get notified when the
            // underlying surface is created and destroyed.
            mHolder = getHolder();
            mHolder.addCallback(this);
            mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
        }

        public void surfaceCreated(SurfaceHolder holder) 
        {
            // The Surface has been created, acquire the camera and tell it where
            // to draw.
    	     camera = Camera.open();
            try {
        	camera.setPreviewDisplay(holder);
            } catch (IOException exception) {
        	camera.release();
        	camera = null;
                // TODO: add more exception handling logic here
            }
        }

        public void surfaceDestroyed(SurfaceHolder holder) 
        {
            // Surface will be destroyed when we return, so stop the preview.
            // Because the CameraDevice object is not a shared resource, it&#39;s very
            // important to release it when the activity is paused.
            camera.stopPreview();
            camera.release();
            camera = null;
        }

        public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) 
        {
            // Now that the size is known, set up the camera parameters and begin
            // the preview.
    
            Camera.Parameters parameters = camera.getParameters();
            parameters.setPreviewSize(w, h);
            camera.setParameters(parameters);
            camera.startPreview();
        }

        @Override
        public void draw(Canvas canvas) 
        {
            super.draw(canvas);
            Paint p= new Paint(Color.RED);
            Log.d(TAG,&quot;draw&quot;);
            canvas.drawText(&quot;PREVIEW&quot;, canvas.getWidth()/2, canvas.getHeight()/2, p );
        }
    }

camera.setParameters failed in android

After learning a bit of how LLVM work I&#39;m really excited about how portable low-level code can be generated and how modular this &#39;thing&#39; is built.

But I discovered today the existence of C-- that seems to share some concepts with LLVM.

So I&#39;m looking for some information helping me understand the main differences between these two projects... and why both exist.

For me LLVM looks a bit like the ultimate Swiss Army knife for compiler infrastructure, and C-- looks far less advanced.

How does C-- compare to LLVM?

After learning a bit of how LLVM work I'm really excited about how portable low-level code can be generated and how modular this 'thing' is built.
But I discovered today the existence of C-- that seems to share some concepts with LLVM.
So I'm looking for some information helping me understand the main differences between these two projects... and why both exist.
For me LLVM looks a bit like the ultimate Swiss Army knife for compiler infrastructure, and C-- looks far less advanced.

&gt; **Possible Duplicates:**  
&gt; [What are the arguments to main() for?](https://stackoverflow.com/questions/3734111/what-are-the-arguments-to-main-for)  
&gt; [What does int argc, char *argv[] mean?](https://stackoverflow.com/questions/3024197/what-does-int-argc-char-argv-mean)  

&lt;!-- End of automatically inserted text --&gt;

Every program is starting with the `main(int argc, char *argv[])` definition. 

I don&#39;t understand what it means. I would be very glad if somebody could explain why we use these arguments if we don&#39;t use them in the program? Why not just: `int main()`?

Is the name of the program one of the elements of `*argv[]` and `argc` is the count of the number of arguments in `*argv[]`? What are the other arguments sent to `*argv[]`? How do we send them?


Regarding &#39;main(int argc, char *argv[])&#39;

Is there any way to dump the call stack in a running process in C or C++ every time a certain function is called?  What I have in mind is something like this:

    void foo()
    {
       print_stack_trace();
    
       // foo&#39;s body
    
       return
    }

Where `print_stack_trace` works similarly to [`caller`][1] in Perl.

Or something like this:

    int main (void)
    {
        // will print out debug info every time foo() is called
        register_stack_trace_function(foo); 
    
        // etc...
    }

where `register_stack_trace_function` puts some sort of internal breakpoint that will cause a stack trace to be printed whenever `foo` is called.

Does anything like this exist in some standard C library?

I am working on Linux, using GCC.

---
## Background ##

I have a test run that behaves differently based on some commandline switches that shouldn&#39;t affect this behavior.  My code has a pseudo-random number generator that I assume is being called differently based on these switches.  I want to be able to run the test with each set of switches and see if the random number generator is called differently for each one.


  [1]: http://perldoc.perl.org/functions/caller.html

print call stack in C or C++

I need to do this to persist operations on the matrix as well. Does that mean that it needs to be passed by reference? 

Will this suffice?
  
```void operate_on_matrix(char matrix[][20]);```

How to pass 2D array (matrix) in a function in C?

When converting an int like so:

    char a[256];
    sprintf(a, &quot;%d&quot;, 132);

what&#39;s the best way to determine how large *a* should be? I assume manually setting it is fine (as I&#39;ve seen it used everywhere), but how large should it be? What&#39;s the largest int value possible on a 32 bit system, and is there some tricky way of determining that on the fly?

Determining sprintf buffer size - what&#39;s the standard?

There is a variable that holds some flags and I want to remove one of them. But I don&#39;t know how to remove it.

Here is how I set the flag.

    my.emask |= ENABLE_SHOOT;



How can I remove a flag in C?

I wanted to know in depth meaning and working of compiler, linker and loader.
With reference to any language preferably c++.


What is compiler, linker, loader?

What&#39;s the difference between `__PRETTY_FUNCTION__`, `__FUNCTION__`, `__func__`, and where are they documented? How do I decide which one to use?

What&#39;s the difference between __PRETTY_FUNCTION__, __FUNCTION__, __func__?

Are they generated by different phases of a compiling process? Or are they just different names for the same thing?

What&#39;s the difference between parse trees and abstract syntax trees (ASTs)?

Does C (or any other low-level language, for that matter) even have source, or is the compiler the part that &quot;does all the work&quot;, including parsing? If so, couldn&#39;t different compilers have different C dialects? Where does the stdlib factor into this? I would really like to know how this works.

Is C open source?

Is there any way to convert C code to JavaScript and from JavaScript to C? I found `V8 juice` which can generate `JavaScript-side` classes from C++, but it&#39;s only one way (C++ to JavaScript).

I&#39;m not looking for a software.

Convert javascript code to c code

**Assembly.GetEntryAssembly()** does not work for web applications.

But... I really need something like that.
I work with some deeply-nested code that is used in both web and non-web applications.

My current solution is to browse the StackTrace to find the first called assembly.


    /// &lt;summary&gt;
    /// Version of &#39;GetEntryAssembly&#39; that works with web applications
    /// &lt;/summary&gt;
    /// &lt;returns&gt;The entry assembly, or the first called assembly in a web application&lt;/returns&gt;
    public static Assembly GetEntyAssembly()
    {
        // get the entry assembly
        var result = Assembly.GetEntryAssembly();
    
        // if none (ex: web application)
        if (result == null)
        {
            // current method
            MethodBase methodCurrent = null;
            // number of frames to skip
            int framestoSkip = 1;
    
    
            // loop until we cannot got further in the stacktrace
            do
            {
                // get the stack frame, skipping the given number of frames
                StackFrame stackFrame = new StackFrame(framestoSkip);
                // get the method
                methodCurrent = stackFrame.GetMethod();
                // if found
                if ((methodCurrent != null)
                    // and if that method is not excluded from the stack trace
                    &amp;&amp; (methodCurrent.GetAttribute&lt;ExcludeFromStackTraceAttribute&gt;(false) == null))
                {
                    // get its type
                    var typeCurrent = methodCurrent.DeclaringType;
                    // if valid
                    if (typeCurrent != typeof (RuntimeMethodHandle))
                    {
                        // get its assembly
                        var assembly = typeCurrent.Assembly;
    
                        // if valid
                        if (!assembly.GlobalAssemblyCache
                            &amp;&amp; !assembly.IsDynamic
                            &amp;&amp; (assembly.GetAttribute&lt;System.CodeDom.Compiler.GeneratedCodeAttribute&gt;() == null))
                        {
                            // then we found a valid assembly, get it as a candidate
                            result = assembly;
                        }
                    }
                }
    
                // increase number of frames to skip
                framestoSkip++;
            } // while we have a working method
            while (methodCurrent != null);
        }
        return result;
    }

To ensure the assembly is what we want, we have 3 conditions :

 - the assembly is not in the GAC
 - the assembly is no dynamic
 - the assembly is not generated (to avoid temporary asp.net files

The last problem I meet is when the base page is defined in a separate assembly.
(I use ASP.Net MVC, but it&#39;ll be the same with ASP.Net).
In that particular case, it&#39;s that separate assembly that is returned, not the one containing the page.

What I am looking for now is :

1) Are my assembly validation conditions enough ? (I may have forgotten cases)

2) Is there a way, from a given code-generated assembly in the ASP.Net temporary folder, to get information about the project that contains that Page / View ?
(I think not, but who knows...)



GetEntryAssembly for web applications

How do I do a `script/generate migration` to create a join table for a `has_and_belongs_to_many` relationship?

The application runs on Rails 2.3.2, but I also have Rails 3.0.3 installed.

Rails migration for has_and_belongs_to_many join table

is it possible to convert a Python program to C/C++?

I need to implement a couple of algorithms, and I&#39;m not sure if the performance gap is big enough to justify all the pain I&#39;d go through when doing it in C/C++ (which I&#39;m not good at). I thought about writing one simple algorithm and benchmark it against such a converted solution. If that alone is significantly faster than the Python version, then I&#39;ll have no other choice than doing it in C/C++.

Convert Python program to C/C++ code?

I&#39;m doing code generation in Jinja2 and I frequently want to iterate through two lists together (i.e. variables names and types), is there a simple way to do this or do I need to just pass a pre-zipped list? I was unable to find such a function in the [docs][1] or googling.


  [1]: http://jinja.pocoo.org/docs/templates/

zip(list1, list2) in Jinja2?

Can a class add a method to itself at runtime (like from a `static` block), so that if someone is performing reflection on this class, they&#39;ll see the new method, even though it wasn&#39;t defined at compile time?

***Background:***

A framework I&#39;m using expects `Action` classes to be defined that have a `doAction(...)` method, by convention. The framework inspects these classes at runtime to see what type of parameters are available in their `doAction()` method. For example: doAction(**String** a, **Integer** b)

I&#39;d like each class to be able to programatically generate its `doAction()` method with various parameters, just-in-time when it is inspected.  The body of the method can be empty.

Can a Java class add a method to itself at runtime?

Looking at the LLVM documentation, they mention that [they use &quot;a custom form of RTTI&quot;][1], and this is the reason they have `isa&lt;&gt;`, `cast&lt;&gt;` and `dyn_cast&lt;&gt;` templated functions.

Usually, reading that a library reimplements some basic functionality of a language is a terrible code smell and just invites to run. However, this is LLVM we&#39;re talking of: the guys are working on a C++ compiler _and_ a C++ runtime. If they don&#39;t know what they&#39;re doing, I&#39;m pretty much screwed because I prefer `clang` to the `gcc` version that ships with Mac OS.

Still, being less experienced than them, I&#39;m left wondering what are the pitfalls of the normal RTTI. I know that it works only for types that have a v-table, but that only raises two questions:

* Since you just need a virtual method to have a vtable, why don&#39;t they just mark a method as `virtual`? Virtual destructors seem to be good at this.
* If their solution doesn&#39;t use regular RTTI, any idea how it was implemented?


  [1]: http://llvm.org/docs/ProgrammersManual.html#isa

What can make C++ RTTI undesirable to use?

I have a question concerning llvm, clang, and gcc on OS X. 

What is the difference between the llvm-gcc 4.2, llvm 2.0 and clang? I know that they all build on llvm but how are they different? 

Besides faster compiling, what is the advantage of llvm over gcc?

LLVM vs clang on OS X

Many dynamic languages implement (or want to implement) a JIT Compiler in order to speed up their execution times. Inevitably, someone from the peanut gallery asks why they don&#39;t use LLVM. The answer is often, &quot;LLVM is unsuitable for building a JIT.&quot; (For Example, Armin Rigo&#39;s comment [here.][1])

**Why is LLVM Unsuitable for building a JIT?**

Note: I know LLVM has its own JIT. If LLVM used to be unsuitable, but now is suitable, please say what changed. I&#39;m not talking about running LLVM Bytecode on the LLVM JIT, I&#39;m talking about using the LLVM libraries to implement a JIT for a dynamic language.


  [1]: http://morepypy.blogspot.com/2008/04/float-operations-for-jit.html?showComment=1208773800000#c6322995253226647458

Why is llvm considered unsuitable for implementing a JIT?

I have a number of projects built using CMake and I&#39;d like to be able to easily switch between using GCC or Clang/LLVM to compile them. I believe (please correct me if I&#39;m mistaken!) that to use Clang I need to set the following:

        SET (CMAKE_C_COMPILER             &quot;/usr/bin/clang&quot;)
        SET (CMAKE_C_FLAGS                &quot;-Wall -std=c99&quot;)
        SET (CMAKE_C_FLAGS_DEBUG          &quot;-g&quot;)
        SET (CMAKE_C_FLAGS_MINSIZEREL     &quot;-Os -DNDEBUG&quot;)
        SET (CMAKE_C_FLAGS_RELEASE        &quot;-O4 -DNDEBUG&quot;)
        SET (CMAKE_C_FLAGS_RELWITHDEBINFO &quot;-O2 -g&quot;)
        
        SET (CMAKE_CXX_COMPILER             &quot;/usr/bin/clang++&quot;)
        SET (CMAKE_CXX_FLAGS                &quot;-Wall&quot;)
        SET (CMAKE_CXX_FLAGS_DEBUG          &quot;-g&quot;)
        SET (CMAKE_CXX_FLAGS_MINSIZEREL     &quot;-Os -DNDEBUG&quot;)
        SET (CMAKE_CXX_FLAGS_RELEASE        &quot;-O4 -DNDEBUG&quot;)
        SET (CMAKE_CXX_FLAGS_RELWITHDEBINFO &quot;-O2 -g&quot;)
        
        SET (CMAKE_AR      &quot;/usr/bin/llvm-ar&quot;)
        SET (CMAKE_LINKER  &quot;/usr/bin/llvm-ld&quot;)
        SET (CMAKE_NM      &quot;/usr/bin/llvm-nm&quot;)
        SET (CMAKE_OBJDUMP &quot;/usr/bin/llvm-objdump&quot;)
        SET (CMAKE_RANLIB  &quot;/usr/bin/llvm-ranlib&quot;)

Is there an easy way of switching between these and the default GCC variables, preferably as a system-wide change rather than project specific (i.e. not just adding them into a project&#39;s CMakeLists.txt)?

Also, is it necessary to use the `llvm-*` programs rather than the system defaults when compiling using clang instead of gcc? What&#39;s the difference?

Switching between GCC and Clang/LLVM using CMake

I would like to view an array of elements pointed to by a pointer. In GDB this can be done by treating the pointed memory as an artificial array of a given length using the operator &#39;@&#39; as

    *pointer @ length
where `length` is the number of elements I want to view.

The above syntax does not work in LLDB supplied with Xcode 4.1.

Is there any way how to accomplish the above in LLDB?

Content Type	Original Author	Original Content on Stackoverflow
Question	Alois Cochard	View Question on Stackoverflow
Solution 1 - C	Prof. Falken	View Answer on Stackoverflow

How does C-- compare to LLVM?

C Problem Overview

C Solutions

Solution 1 - C

camera.setParameters failed in android

How to load CSS using jquery

Attributions