Hi, I'm trying to get the dictionary add-on to work with ref-counted strings. After I replaced all the uses of std::string with my own most things worked except for the initialization lists and index operators. I was able to initialization lists working with the following change to how the name is extracted:

UString *name = *(UString**)buffer;
buffer += sizeof(UString*);

That fixed that issue, but now I'm getting a crash when attempting to retrieve the data using the index operators

dictionary dict = { {"test", "foo"} };
dictionaryValue val = dict["test"];
stdout << string(val);

That will cause a crash when attempting to call opEquals on the string object. The following will work:

dictionary dict = { {"test", "foo"} };
string val;
dict.get("test", val);
stdout << val;

I'm sure the pointer it's using for the string class is not correct, but any ideas on why that would be? I attached a valgrind log.

Thanks

[attachment=27620:valgrind.txt]

I've registered it with the following:

r = engine->RegisterObjectMethod("string", "string &opAssign(const string &in)", asMETHODPR(UString, operator=, (const UString&), UString&), asCALL_THISCALL); assert(r>=0);

Here is the operator= method

UString& UString::operator=(const UString& other)
{
    mData = other.mData;
    return *this;
}

Attached is the full UString source.

Thanks

[attachment=27636:UString.cpp.txt]

I decided to test this against the scriptstring add-on from testing, and it fails the same way. Here is my test code:

#include <angelscript.h>
#include <scriptstring.h>
#include <scriptdictionary.h>
#include <scriptarray.h>
#include <scripthelper.h>
#include <stdio.h>

void MessageCallback(const asSMessageInfo *msg, void *param)
{
	const char *type = "ERR ";
	if( msg->type == asMSGTYPE_WARNING ) 
		type = "WARN";
	else if( msg->type == asMSGTYPE_INFORMATION ) 
		type = "INFO";

	printf("%s (%d, %d) : %s : %s\n", msg->section, msg->row, msg->col, type, msg->message);
}

int main()
{
    asIScriptEngine *engine = asCreateScriptEngine(ANGELSCRIPT_VERSION);
	engine->SetMessageCallback(asFUNCTION(MessageCallback), 0, asCALL_CDECL);
    
    RegisterScriptString(engine);
    RegisterScriptArray(engine, true);
    RegisterScriptDictionary(engine);

    int r = ExecuteString(engine, 
            "dictionary dict = { { \"foo\", \"bar\" } };\n"
            "string s = string(dict[\"foo\"]);\n");

    return 0;

}

I made the following change to scriptdictionary to use pointers for the key

// Get the name value pair from the buffer and insert it in the dictionary
string name = **(string**)buffer;
buffer += sizeof(string*);

Here is the GDB backtrace

Program received signal SIGSEGV, Segmentation fault.
0x00007ffff7b2c43b in std::string::assign(std::string const&) ()
   from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
(gdb) bt
#0  0x00007ffff7b2c43b in std::string::assign(std::string const&) ()
   from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#1  0x0000000000409569 in CScriptString::operator= (this=0x7ba3d0, other=...)
    at /home/droz/trunk/sdk/tests/test_feature/source/scriptstring.cpp:76
#2  0x000000000048c0bc in endstack ()
#3  0x0000000000402950 in std::string::compare(std::string const&) const@plt ()
#4  0x00007fffffffe120 in ?? ()
#5  0x0000000000000000 in ?? ()

Again, here is valgrind log

==14332== Invalid read of size 4
==14332==    at 0x4F0549E: std::string::assign(std::string const&) (in /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.21)
==14332==    by 0x409568: CScriptString::operator=(CScriptString const&) (scriptstring.cpp:76)
==14332==    by 0x48C0BB: X64_CallFunction(unsigned long const*, int, unsigned long (*)(), unsigned long&, bool) (in /home/droz/test)
==14332==    by 0x48CCE6: CallSystemFunctionNative(asCContext*, asCScriptFunction*, void*, unsigned int*, void*, unsigned long&, void*) (in /home/droz/test)
==14332==    by 0x48BA86: CallSystemFunction(int, asCContext*) (in /home/droz/test)
==14332==    by 0x421820: asCContext::ExecuteNext() (in /home/droz/test)
==14332==    by 0x41E965: asCContext::Execute() (in /home/droz/test)
==14332==    by 0x41571F: ExecuteString(asIScriptEngine*, char const*, void*, int, asIScriptModule*, asIScriptContext*) (scripthelper.cpp:183)
==14332==    by 0x41549B: ExecuteString(asIScriptEngine*, char const*, asIScriptModule*, asIScriptContext*) (scripthelper.cpp:137)
==14332==    by 0x402B62: main (test.cpp:30)
==14332==  Address 0x5cfd708 is 8 bytes before a block of size 16 alloc'd
==14332==    at 0x4C2B0E0: operator new(unsigned long) (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==14332==    by 0x40B218: StringDefaultFactory() (scriptstring.cpp:618)
==14332==    by 0x48C0BB: X64_CallFunction(unsigned long const*, int, unsigned long (*)(), unsigned long&, bool) (in /home/droz/test)
==14332==    by 0x48CCE6: CallSystemFunctionNative(asCContext*, asCScriptFunction*, void*, unsigned int*, void*, unsigned long&, void*) (in /home/droz/test)
==14332==    by 0x48BA86: CallSystemFunction(int, asCContext*) (in /home/droz/test)
==14332==    by 0x421820: asCContext::ExecuteNext() (in /home/droz/test)
==14332==    by 0x41E965: asCContext::Execute() (in /home/droz/test)
==14332==    by 0x41571F: ExecuteString(asIScriptEngine*, char const*, void*, int, asIScriptModule*, asIScriptContext*) (scripthelper.cpp:183)
==14332==    by 0x41549B: ExecuteString(asIScriptEngine*, char const*, asIScriptModule*, asIScriptContext*) (scripthelper.cpp:137)
==14332==    by 0x402B62: main (test.cpp:30)
==14332== 
==14332== Invalid free() / delete / delete[] / realloc()
==14332==    at 0x4C2C2BC: operator delete(void*) (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==14332==    by 0x4F054B7: std::string::assign(std::string const&) (in /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.21)
==14332==    by 0x409568: CScriptString::operator=(CScriptString const&) (scriptstring.cpp:76)
==14332==    by 0x48C0BB: X64_CallFunction(unsigned long const*, int, unsigned long (*)(), unsigned long&, bool) (in /home/droz/test)
==14332==    by 0x48CCE6: CallSystemFunctionNative(asCContext*, asCScriptFunction*, void*, unsigned int*, void*, unsigned long&, void*) (in /home/droz/test)
==14332==    by 0x48BA86: CallSystemFunction(int, asCContext*) (in /home/droz/test)
==14332==    by 0x421820: asCContext::ExecuteNext() (in /home/droz/test)
==14332==    by 0x41E965: asCContext::Execute() (in /home/droz/test)
==14332==    by 0x41571F: ExecuteString(asIScriptEngine*, char const*, void*, int, asIScriptModule*, asIScriptContext*) (scripthelper.cpp:183)
==14332==    by 0x41549B: ExecuteString(asIScriptEngine*, char const*, asIScriptModule*, asIScriptContext*) (scripthelper.cpp:137)
==14332==    by 0x402B62: main (test.cpp:30)
==14332==  Address 0x5cfd6f8 is 24 bytes before a block of size 16 alloc'd
==14332==    at 0x4C2B0E0: operator new(unsigned long) (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==14332==    by 0x40B218: StringDefaultFactory() (scriptstring.cpp:618)
==14332==    by 0x48C0BB: X64_CallFunction(unsigned long const*, int, unsigned long (*)(), unsigned long&, bool) (in /home/droz/test)
==14332==    by 0x48CCE6: CallSystemFunctionNative(asCContext*, asCScriptFunction*, void*, unsigned int*, void*, unsigned long&, void*) (in /home/droz/test)
==14332==    by 0x48BA86: CallSystemFunction(int, asCContext*) (in /home/droz/test)
==14332==    by 0x421820: asCContext::ExecuteNext() (in /home/droz/test)
==14332==    by 0x41E965: asCContext::Execute() (in /home/droz/test)
==14332==    by 0x41571F: ExecuteString(asIScriptEngine*, char const*, void*, int, asIScriptModule*, asIScriptContext*) (scripthelper.cpp:183)
==14332==    by 0x41549B: ExecuteString(asIScriptEngine*, char const*, asIScriptModule*, asIScriptContext*) (scripthelper.cpp:137)
==14332==    by 0x402B62: main (test.cpp:30)
==14332== 
==14332== Invalid read of size 8
==14332==    at 0x4F0542B: std::string::assign(std::string const&) (in /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.21)
==14332==    by 0x409568: CScriptString::operator=(CScriptString const&) (scriptstring.cpp:76)
==14332==    by 0x48C0BB: X64_CallFunction(unsigned long const*, int, unsigned long (*)(), unsigned long&, bool) (in /home/droz/test)
==14332==    by 0x48CCE6: CallSystemFunctionNative(asCContext*, asCScriptFunction*, void*, unsigned int*, void*, unsigned long&, void*) (in /home/droz/test)
==14332==    by 0x48BA86: CallSystemFunction(int, asCContext*) (in /home/droz/test)
==14332==    by 0x421820: asCContext::ExecuteNext() (in /home/droz/test)
==14332==    by 0x41E965: asCContext::Execute() (in /home/droz/test)
==14332==    by 0x41571F: ExecuteString(asIScriptEngine*, char const*, void*, int, asIScriptModule*, asIScriptContext*) (scripthelper.cpp:183)
==14332==    by 0x41549B: ExecuteString(asIScriptEngine*, char const*, asIScriptModule*, asIScriptContext*) (scripthelper.cpp:137)
==14332==    by 0x402B62: main (test.cpp:30)
==14332==  Address 0x5cfd458 is 24 bytes inside a block of size 28 alloc'd
==14332==    at 0x4C2B0E0: operator new(unsigned long) (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==14332==    by 0x4F03F68: std::string::_Rep::_S_create(unsigned long, unsigned long, std::allocator<char> const&) (in /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.21)
==14332==    by 0x4F0423A: std::string::_M_mutate(unsigned long, unsigned long, unsigned long) (in /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.21)
==14332==    by 0x4F0485D: std::string::_M_replace_safe(unsigned long, unsigned long, char const*, unsigned long) (in /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.21)
==14332==    by 0x409354: CScriptString::CScriptString(char const*, unsigned int) (scriptstring.cpp:22)
==14332==    by 0x40B161: StringFactory(unsigned int, char const*) (scriptstring.cpp:603)
==14332==    by 0x48C0BB: X64_CallFunction(unsigned long const*, int, unsigned long (*)(), unsigned long&, bool) (in /home/droz/test)
==14332==    by 0x48CCE6: CallSystemFunctionNative(asCContext*, asCScriptFunction*, void*, unsigned int*, void*, unsigned long&, void*) (in /home/droz/test)
==14332==    by 0x48BA86: CallSystemFunction(int, asCContext*) (in /home/droz/test)
==14332==    by 0x421820: asCContext::ExecuteNext() (in /home/droz/test)
==14332==    by 0x41E965: asCContext::Execute() (in /home/droz/test)
==14332==    by 0x41571F: ExecuteString(asIScriptEngine*, char const*, void*, int, asIScriptModule*, asIScriptContext*) (scripthelper.cpp:183)
==14332== 
==14332== Invalid read of size 4
==14332==    at 0x4F0543B: std::string::assign(std::string const&) (in /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.21)
==14332==    by 0x409568: CScriptString::operator=(CScriptString const&) (scriptstring.cpp:76)
==14332==    by 0x48C0BB: X64_CallFunction(unsigned long const*, int, unsigned long (*)(), unsigned long&, bool) (in /home/droz/test)
==14332==    by 0x48CCE6: CallSystemFunctionNative(asCContext*, asCScriptFunction*, void*, unsigned int*, void*, unsigned long&, void*) (in /home/droz/test)
==14332==    by 0x48BA86: CallSystemFunction(int, asCContext*) (in /home/droz/test)
==14332==    by 0x421820: asCContext::ExecuteNext() (in /home/droz/test)
==14332==    by 0x41E965: asCContext::Execute() (in /home/droz/test)
==14332==    by 0x41571F: ExecuteString(asIScriptEngine*, char const*, void*, int, asIScriptModule*, asIScriptContext*) (scripthelper.cpp:183)
==14332==    by 0x41549B: ExecuteString(asIScriptEngine*, char const*, asIScriptModule*, asIScriptContext*) (scripthelper.cpp:137)
==14332==    by 0x402B62: main (test.cpp:30)
==14332==  Address 0x72615a is not stack'd, malloc'd or (recently) free'd
==14332== 
==14332== 
==14332== Process terminating with default action of signal 11 (SIGSEGV)
==14332==  Access not within mapped region at address 0x72615A
==14332==    at 0x4F0543B: std::string::assign(std::string const&) (in /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.21)
==14332==    by 0x409568: CScriptString::operator=(CScriptString const&) (scriptstring.cpp:76)
==14332==    by 0x48C0BB: X64_CallFunction(unsigned long const*, int, unsigned long (*)(), unsigned long&, bool) (in /home/droz/test)
==14332==    by 0x48CCE6: CallSystemFunctionNative(asCContext*, asCScriptFunction*, void*, unsigned int*, void*, unsigned long&, void*) (in /home/droz/test)
==14332==    by 0x48BA86: CallSystemFunction(int, asCContext*) (in /home/droz/test)
==14332==    by 0x421820: asCContext::ExecuteNext() (in /home/droz/test)
==14332==    by 0x41E965: asCContext::Execute() (in /home/droz/test)
==14332==    by 0x41571F: ExecuteString(asIScriptEngine*, char const*, void*, int, asIScriptModule*, asIScriptContext*) (scripthelper.cpp:183)
==14332==    by 0x41549B: ExecuteString(asIScriptEngine*, char const*, asIScriptModule*, asIScriptContext*) (scripthelper.cpp:137)
==14332==    by 0x402B62: main (test.cpp:30)
==14332==  If you believe this happened as a result of a stack
==14332==  overflow in your program's main thread (unlikely but
==14332==  possible), you can try to increase the size of the
==14332==  main thread stack using the --main-stacksize= flag.
==14332==  The main thread stack size used in this run was 8388608.

1. Thanks for pointing that out, eventually it would have caused me a issue.

2. The substr method in ustring does return by value, but that isn't exposed to angelscript. The ref-counting is only really used for the scripting language, internally I use UString as a value type.

r = engine->RegisterObjectMethod("string", "string@ substr(size_t s=0, size_t l=size_t(-1)) const", asFUNCTION(UStringSubstr), asCALL_CDECL_OBJLAST); assert(r>=0);

UString* UStringSubstr(std::size_t pos, std::size_t len, const UString& obj) { return new UString(obj.substr(pos, len)); }

Using the cast<string> does work, thanks for the help.

Thanks, works great now.