AutoHotkey Community

[Laszlo]

There are already scripts posted to the Forum, which pass a program stored in an AHK string to a compiler/interpreter, and retrieve the result. E.g., for Lua the script here works fine, but it uses temporary files, which can cause problems with name conflicts, write permissions, etc. To avoid this problem, we need a compiler, which takes its input from memory, and writes its output also to memory.

The smallest C compiler of this kind I know of is tcc, Fabrice Bellard's Tiny C Compiler. For the easiest use it has to be compiled to a Windows dll, which needs some tweaking, described by Adel Amro. You can also download the version I used from here. Just unzip it to a directory of your choice. I used c:\tcclib. It has two subdirectories, the original "include" and "lib" of tcc, with the compiled libtcc.dll and libtcc.def added. All together about 800KB. (If you install tcc, you only need to copy these two files to its "lib" subdirectory, all others are already there.)

We interface AHK to this dll, with appropriate dllcall's. There are not too many of them:

"LoadLibrary" to keep the dll in memory while needed
"tcc_new" to create a C compiler context (allocate memory, establish internal data structures)
"tcc_add_sysinclude_path" to tell it where its include (header) files are
"tcc_add_library_path" to tell it where the library is
"tcc_compile_string" to compile a program stored as a string
"tcc_run" to run it
"tcc_delete" to remove the compiler context
"FreeLibrary" to unload the dll from memory.

We have to tell the C program, where in memory to write its result. For that we allocate a large enough AHK variable, and write its <address> directly to the C source code as
char* _result = <address>;
The C program has to write its result as a string to the place _result points to, which is our AHK variable, directly available after the program terminates.

The usage is simple:
1. Assign the C source code to an AHK variable, as string. Make sure that all % are escaped with `, there is no ; or ) in the first position in a continuation line.
2. You can have references to AHK variables between % signs (%i%)
3. Include a declaration in main(): "char* _result;". The target of this pointer has to be updated with the result we want to see from the C program.
4. Run the C program with the Run function below. Its parameters are: the path to the directory containing libtcc.dll, the AHK string containing the C program and optionally an upper bound on the length of the returned AHK string:

[Chris]

Really amazing; great resource! Thanks for putting it all together and explaining it so clearly.

[majkinetor]

Absolutely fantastic.
I will go to try this imediately

If #PP directive is ever added I will make real we have something like asm directive in C. So we could write:

[Sean]

Looks great.
It's too bad that I don't know C.

[corrupt]

Interesting. Thanks

[majkinetor]

Hm... I get empty msg box .
I extracted archive in C: and run your script. Empty msgbox.
_________________

[Laszlo]

Please verify if the c:\tcclib directory contains 2 subdirectories, inc and lib. (Unzip has to be performed, so the paths of files are re-created.) If all is fine, add before the Return x command:

[Laszlo]

If there are no error messages, most likely the sprintf function is not found. If the runtime C library is there, you could try to explicitly include the relevant header file: #include <stdio.h>.

The simplest C program should work, too:

[majkinetor]

No changes.

Ok, this is what I did

1. Example tcc\tcc -Iinclude -Llib examples/fib.c works. It produces working exe.

2. I downloaded your archive and extracted it to C so I have the same structure as you.

3. I saved your example in c:\tclib and executed it. I was changing example to something easy like "hello word" sprintf but nothing worked.

4. I downed latest AHK, didn't help

5. I checked program you are sending after regExp. The _result line is correct, memory is the same. Furhtermore I checked variable with HexView. This is the code I was using:

[Laszlo]

Add #NoEnv in front of the script. Maybe, some environment variables conflict with internal names.

[Laszlo]

I updated the tcclib.zip file. It contains now a TEST.ahk file in the topmost level. Unzip it anywhere, with maintaining the relative paths of files. Double clicking on TEST.ahk (or running it otherwise) should pop up a Hello World message box, and one with
f(101) --> 10.04987562112089
testing sprintf and the floating point library.

[majkinetor]

[Laszlo]

You are right, it is funny. I filed a bug report.

[Laszlo]

If you embed a longer C program, and it has errors, a "Compile error" message is not very helpful. For more information, there is a callback mechanism in libtcc:

[majkinetor]