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hello,
i'm making a game engine and for compiling my scripts, i'm using SDL_Rwops
the scripting language is squirrel and it works, because it use's FILE*, but i want to compile my scripts into memory
this is my code:
SQInteger rwops_write(SQUserPointer dest, SQUserPointer src, SQInteger sz)
{
SDL_RWops* rw = (SDL_RWops*)dest;
return SDL_RWwrite(rw, src, sz, 1) == 1 ? SQ_OK : SQ_ERROR;
}

string compile()
{
char* buf=new char;
SDL_RWops *r=SDL_AllocRW();
if(!r)
{
Error::Throw(vm, "could not allocate memory");
return nullptr;
}
#if !defined (SCRAT_NO_ERROR_CHECKING)
if(!sq_isnull(obj))
{
sq_pushobject(vm, obj);
sq_writeclosure(vm, rwops_write, r);
}
#else
sq_pushobject(vm, obj);
sq_writeclosure(vm, rwops_write, r);
#endif
sq_pop(vm, 1);
SDL_RWread(r, buf, SDL_RWsize(r), 1);
return buf;
}

what is the problem, and how to fix it
thanks, amir

this is the debug log from GDB:
Building to ensure sources are up-to-date
Selecting target:
Debug
Adding source dir: F:\projects\cpp\advanced audio game engine\
Adding source dir: F:\projects\cpp\advanced audio game engine\
Adding file: F:\projects\cpp\advanced audio game engine\bin\Debug\aage.exe
Changing directory to: F:/projects/cpp/ADVANC~1/bin/Debug
Set variable: PATH=.;C:\Dev-Cpp\bin;C:\Dev-Cpp;C:\Python34;C:\Python34\Scripts;C:\Program
Files (x86)\cmake\bin;C:\Program Files (x86)\Intel\iCLS
Client;C:\Program Files\Intel\iCLS
Client;C:\Windows\System32;C:\Windows;C:\Windows\System32\wbem;C:\Windows\System32\WindowsPowerShell\v1.0;C:\Program
Files (x86)\Intel\OpenCL SDK\2.0\bin\x86;C:\Program Files
(x86)\Intel\OpenCL SDK\2.0\bin\x64;C:\Program Files\Intel\Intel(R)
Management Engine Components\DAL;C:\Program Files\Intel\Intel(R)
Management Engine Components\IPT;C:\Program Files (x86)\Intel\Intel(R)
Management Engine Components\DAL;C:\Program Files (x86)\Intel\Intel(R)
Management Engine Components\IPT;C:\Program
Files\TortoiseSVN\bin;C:\Program Files (x86)\Skype\Phone

[debug]Command-line: C:\Dev-Cpp\bin\gdb.exe -nx -fullname -quiet
-args F:/projects/cpp/ADVANC~1/bin/Debug/aage.exe
[debug]Working dir : F:\projects\cpp\ADVANC~1\bin\Debug

Starting debugger: C:\Dev-Cpp\bin\gdb.exe -nx -fullname -quiet -args
F:/projects/cpp/ADVANC~1/bin/Debug/aage.exe
done

[debug]> set prompt >>>>>>cb_gdb:

Registered new type: wxString
Registered new type: STL String
Registered new type: STL Vector
Setting breakpoints

[debug]Reading symbols from F:/projects/cpp/ADVANC~1/bin/Debug/aage.exe...
[debug]done.
[debug](gdb)
[debug]>>>>>>cb_gdb:
[debug]> show version
[debug]GNU gdb (GDB) 7.9.1
[debug]Copyright (C) 2015 Free Software Foundation, Inc.
[debug]License GPLv3+: GNU GPL version 3 or later
<http://gnu.org/licenses/gpl.html>
[debug]This is free software: you are free to change and redistribute it.
[debug]There is NO WARRANTY, to the extent permitted by law. Type
"show copying"
[debug]and "show warranty" for details.
[debug]This GDB was configured as "i686-w64-mingw32".
[debug]Type "show configuration" for configuration details.
[debug]For bug reporting instructions, please see:
[debug]<http://www.gnu.org/software/gdb/bugs/>.
[debug]Find the GDB manual and other documentation resources online at:
[debug]<http://www.gnu.org/software/gdb/documentation/>.
[debug]For help, type "help".
[debug]Type "apropos word" to search for commands related to "word".
[debug]>>>>>>cb_gdb:
[debug]> set confirm off

Debugger name and version: GNU gdb (GDB) 7.9.1

[debug]>>>>>>cb_gdb:
[debug]> set width 0
[debug]>>>>>>cb_gdb:
[debug]> set height 0
[debug]>>>>>>cb_gdb:
[debug]> set breakpoint pending on
[debug]>>>>>>cb_gdb:
[debug]> set print asm-demangle on
[debug]>>>>>>cb_gdb:
[debug]> set unwindonsignal on
[debug]>>>>>>cb_gdb:
[debug]> set print elements 0
[debug]>>>>>>cb_gdb:
[debug]> set new-console on
[debug]>>>>>>cb_gdb:
[debug]> set disassembly-flavor att
[debug]>>>>>>cb_gdb:
[debug]> catch throw
[debug]Catchpoint 1 (throw)
[debug]>>>>>>cb_gdb:
[debug]> source C:\Program Files
(x86)\CodeBlocks\share\codeblocks/scripts/stl-views-1.0.3.gdb
[debug]>>>>>>cb_gdb:
[debug]> directory F:/projects/cpp/ADVANC~1/
[debug]Source directories searched: F:/projects/cpp/ADVANC~1;$cdir;$cwd
[debug]>>>>>>cb_gdb:
[debug]> set args hello.aage -c -o hello.exe
[debug]>>>>>>cb_gdb:
[debug]> run
[debug]Starting program: F:\projects\cpp\ADVANC~1\bin\Debug\aage.exe
hello.aage -c -o hello.exe

Child process PID: 93804

[debug][New Thread 93804.0x1750c]
[debug][New Thread 93804.0x16db0]
[debug][New Thread 93804.0x16cec]
[debug][New Thread 93804.0x1705c]
[debug]Program received signal SIGSEGV, Segmentation fault.
[debug]0x00000000 in ?? ()
[debug]>>>>>>cb_gdb:

Program received signal SIGSEGV, Segmentation fault.
In ?? () ()

[debug]> bt 30
[debug]#0 0x00000000 in ?? ()
[debug]#1 0x00430010 in Sqrat::rwops_write (dest=0x3331d0,
src=0x28f2fa, sz=2) at F:/projects/cpp/advanced audio game
engine/include/sqrat/sqratScript.h:44
[debug]#2 0x004601dc in sq_writeclosure (v=0x3ad0c0, w=0x42ffe0
<Sqrat::rwops_write(void*, void*, int)>, up=0x3331d0) at
F:\projects\cpp\advanced audio game engine\src\squirrel\sqapi.cpp:1156
[debug]#3 0x005f0bce in Sqrat::Script::CompileToMemory[abi:cxx11]()
(this=0x28fe3c) at F:/projects/cpp/advanced audio game
engine/include/sqrat/sqratScript.h:262
[debug]#4 0x004302a3 in comp (scr=..., out=...) at
F:\projects\cpp\advanced audio game engine\src\main.cpp:75
[debug]#5 0x004318d7 in WinMain@16 (hInst=0x400000, hPrevInst=0x0,
cmdLine=0x19a3d9e "hello.aage -c -o hello.exe", showtype=10) at
F:\projects\cpp\advanced audio game engine\src\main.cpp:298
[debug]#6 0x0070663d in main ()
[debug]>>>>>>cb_gdb:
[debug]> frame 1
[debug]#1 0x00430010 in Sqrat::rwops_write (dest=0x3331d0,
src=0x28f2fa, sz=2) at F:/projects/cpp/advanced audio game
engine/include/sqrat/sqratScript.h:44
[debug]F:\projects\cpp\advanced audio game
engine\include\sqrat\sqratScript.h:44:1335:beg:0x430010
[debug]>>>>>>cb_gdb:

#1 0x00430010 in Sqrat::rwops_write (dest=0x3331d0, src=0x28f2fa,
sz=2) at F:/projects/cpp/advanced audio game
engine/include/sqrat/sqratScript.h:44
F:\projects\cpp\advanced audio game
engine\include\sqrat\sqratScript.h:44:1335:beg:0x430010
At F:\projects\cpp\advanced audio game engine\include\sqrat\sqratScript.h:44

[debug]> bt 30
[debug]#0 0x00000000 in ?? ()
[debug]#1 0x00430010 in Sqrat::rwops_write (dest=0x3331d0,
src=0x28f2fa, sz=2) at F:/projects/cpp/advanced audio game
engine/include/sqrat/sqratScript.h:44
[debug]#2 0x004601dc in sq_writeclosure (v=0x3ad0c0, w=0x42ffe0
<Sqrat::rwops_write(void*, void*, int)>, up=0x3331d0) at
F:\projects\cpp\advanced audio game engine\src\squirrel\sqapi.cpp:1156
[debug]#3 0x005f0bce in Sqrat::Script::CompileToMemory[abi:cxx11]()
(this=0x28fe3c) at F:/projects/cpp/advanced audio game
engine/include/sqrat/sqratScript.h:262
[debug]#4 0x004302a3 in comp (scr=..., out=...) at
F:\projects\cpp\advanced audio game engine\src\main.cpp:75
[debug]#5 0x004318d7 in WinMain@16 (hInst=0x400000, hPrevInst=0x0,
cmdLine=0x19a3d9e "hello.aage -c -o hello.exe", showtype=10) at
F:\projects\cpp\advanced audio game engine\src\main.cpp:298
[debug]#6 0x0070663d in main ()
[debug]>>>>>>cb_gdb:
[debug]> frame 1
[debug]#1 0x00430010 in Sqrat::rwops_write (dest=0x3331d0,
src=0x28f2fa, sz=2) at F:/projects/cpp/advanced audio game
engine/include/sqrat/sqratScript.h:44
[debug]F:\projects\cpp\advanced audio game
engine\include\sqrat\sqratScript.h:44:1335:beg:0x430010
[debug]>>>>>>cb_gdb:

#1 0x00430010 in Sqrat::rwops_write (dest=0x3331d0, src=0x28f2fa,
sz=2) at F:/projects/cpp/advanced audio game
engine/include/sqrat/sqratScript.h:44
F:\projects\cpp\advanced audio game
engine\include\sqrat\sqratScript.h:44:1335:beg:0x430010


i'm using GCC 5.1 MinGW-w64 with code::blocks 13.12

Û±Û³Û¹Û´-Û°Û¸-Û±Û¶ Û±Ûµ:Û´Û² GMT+Û°Û³:Û³Û°, brightening-eyes:
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As far as I can tell, you're not assigning any memory for the RWops to work on.  SDL_AllocRW() does not create a working buffer, only the rwops object.  I would instead use SDL_RWFromMem(buf, buf_size) to create the rwops.

It also looks like your memory buffer only has a size of 1 byte.  And you're not freeing this memory nor the rwops.  There may be other issues, but try allocating the buffer like so:
char buf[MAX_BUF_SIZE];


And then before the compile() function is over:
SDL_RWclose(r);


Jonny D


On Saturday, November 7, 2015, brightening-eyes wrote:

i don't know how mutch size should be allocated into memory
because maybe the script get's longer and the size may not be sufficient
thanks

Û±Û³Û¹Û´-Û°Û¸-Û±Û¶ Û±Û¹:Û²Û· GMT+Û°Û³:Û³Û°, Jonathan Dearborn:
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If you can't specify a maximum size, then you have to count it dynamically.  Either count up the size you need, calculate it somehow, or cut it into smaller parts (each with a reasonable max size) that you can feed into a growable container (e.g. a file or a C++ string object).  Just remember to delete temporarily allocated memory.


Jonny D






On Sat, Nov 7, 2015 at 9:16 PM, Amir Ramezani wrote:

i've specified the maximam size of 256, i think it's sufficient
but, how to make char* to grow itself up?

Û±Û³Û¹Û´-Û°Û¸-Û±Û· Û¶:Û³Ûµ GMT+Û°Û³:Û³Û°, Jonathan Dearborn:
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char* doesn't grow and the SDL_RWops wouldn't be able to handle it if you tried.  If you need more explicit help with this, you can email me off-list.

Jonny D


On Sat, Nov 7, 2015 at 10:27 PM, Amir Ramezani wrote:

Here is some sample code to get you to see how to dynamically allocate data.

    SDL_RWops* io = SDL_RWFromFile(file_path, "r");
    char* line = NULL;
    if (io != NULL) {
        char name[1];
        size_t amnt_read = 0;
        size_t index = 0;
        size_t buffer = 4096; //this is the chunk size
        line = (char*)malloc(sizeof(char) * buffer);
        while (amnt_read = SDL_RWread(io, name, sizeof(name), 1) > 0) {
            line[index] = (char)name[0];
            ++index;
            if (index == buffer - 1) {
                buffer = buffer * 2;
                line = realloc(line, buffer);
                if (line != NULL) {
                    SDL_Log("\nreallocing %zu bytes to load %s\n", buffer,
                            file_path);
                } else {
                    SDL_Log("\nfailed to realloc %zu bytes to load %s\n",
                            buffer, file_path);
                }
            }
            line = realloc(line, (sizeof(char) * (index + 1)));
            line[index] = '\0';
        }
        line[index] = '\0';


        return line;
        SDL_RWclose(io);
    } else {
        SDL_Log(
            "FAILED TO ALLOCATE RESOURCE\n",
            file_path);
    }
    return line;



the realloc will make the memory grow by 4096 bytes but then in the end it shrinks back down to fit the memory to what you needed without wasting too much excess space.


This should give u a good place to start.




On Sun, Nov 8, 2015 at 11:31 AM, Jonathan Dearborn wrote:

i know realloc, but what about with new and delete?
i want to use C++ memory management ruteens, and i don't know
something other than new and delete
thanks

Û±Û³Û¹Û´-Û°Û¸-Û±Û· Û·:Û°Û· GMT+Û°Û³:Û³Û°, Owen Alanzo Hogarth:
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guys, this is the newly modified code, it doesn't crash, but it give's
an empty string:
string Compile()
{
char* buf=new char[1024];
SDL_RWops *r=SDL_RWFromMem(buf, 1024);
if(!r)
{
Error::Throw(vm, "could not allocate memory");
return nullptr;
}
#if !defined (SCRAT_NO_ERROR_CHECKING)
if(!sq_isnull(obj))
{
sq_pushobject(vm, obj);
sq_writeclosure(vm, rwops_write, (void*) r);
}
#else
sq_pushobject(vm, obj);
sq_writeclosure(vm, rwops_write, (void*) r);
#endif
sq_pop(vm, 1);
SDL_RWread(r, buf, SDL_RWsize(r), 1);
SDL_RWclose(r);
return buf;
}

what to do in order to compile it successfully into string?
thanks

Û±Û³Û¹Û´-Û°Û¸-Û±Û· Û·:Û²Û´ GMT+Û°Û³:Û³Û°, Amir Ramezani:
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