The specified procedure could not be found. about jna HOT 8 CLOSED

Function names are case sensitive.

On Apr 3, 2012, at 11:33 AM, write2warriors wrote:

Hi, I am getting the following error. Please help.
java.lang.UnsatisfiedLinkError: Error looking up function 'funcA': The specified procedure could not be found.

Am I doing something wrong?

Using the Dependency Walker, it shows MY.DLL has the following dependency and functions:

MY.DLL has a dependency on Kernel32.DLL. Kernel32.DLL has a dependency on NTDLL.DLL

functions:
class SomeClass & SomeClass::operator=(class SomeClass const &)
void FuncA(unsigned short,unsigned char *,unsigned char *)
int FuncB(unsigned char *,unsigned char *)

My JNA interface:

public interface MyDll extends Library {
void funcA(short len, char[] input, char[] output);
int funcB(char[] input, char[] output);
}

Calling:
char[] input = new char[] { [char array initialization] };
char[] output = new char[8]; // output has no more than 8 characters

MyDll myDll = (MyDll) Native.loadLibrary("C:[some path]\my.dll", My.class);
myDll.ecrMac(input, output);

The library is loaded, but why am I getting the error
java.lang.UnsatisfiedLinkError: Error looking up function 'funcA': The specified procedure could not be found.

---

Reply to this email directly or view it on GitHub:
#65

from jna.

It was a typo in this report. The function names are the same as the ones shown in Dependency Walker

from jna.

let me retype this. I apologize for the typo.

Using the Dependency Walker, it shows MY.DLL has the following dependency and functions:

MY.DLL has a dependency on Kernel32.DLL. Kernel32.DLL has a dependency on NTDLL.DLL

functions:
class SomeClass & SomeClass::operator=(class SomeClass const &)
void FuncA(unsigned short,unsigned char *,unsigned char *)
int FuncB(unsigned char *,unsigned char *)

My JNA interface:

public interface MyDll extends Library {

void FuncA(short len, char[] input, char[] output);
int FuncB(char[] input, char[] output);
}

Calling:
char[] input = new char[] { [char array initialization] };
char[] output = new char[8]; // output has no more than 8 characters

MyDll myDll = (MyDll) Native.loadLibrary("C:[some path]\my.dll", My.class);
myDll.FuncB(input, output);

The library is loaded, but why am I getting the error
java.lang.UnsatisfiedLinkError: Error looking up function 'FuncA': The specified procedure could not be found.

Do I need to have an interface for the overloading operator=? It's something I don't need. If so, how?

from jna.

Does dependency walker show those function names exported exactly as "FuncA" and "FuncB"?

If you are using a C++ compiler, you must use 'extern "C"' in order to avoid name mangling; stdcall calling convention will also add a suffix to function names.

On Apr 3, 2012, at 7:04 PM, write2warriors wrote:

let me retype this. I apologize for the typo.

Using the Dependency Walker, it shows MY.DLL has the following dependency and functions:

MY.DLL has a dependency on Kernel32.DLL. Kernel32.DLL has a dependency on NTDLL.DLL

functions:
class SomeClass & SomeClass::operator=(class SomeClass const &)
void FuncA(unsigned short,unsigned char *,unsigned char *)
int FuncB(unsigned char *,unsigned char *)

My JNA interface:

public interface MyDll extends Library {

void FuncA(short len, char[] input, char[] output);
int FuncB(char[] input, char[] output);
}

Calling:
char[] input = new char[] { [char array initialization] };
char[] output = new char[8]; // output has no more than 8 characters

MyDll myDll = (MyDll) Native.loadLibrary("C:[some path]\my.dll", My.class);
myDll.FuncA(input, output);

The library is loaded, but why am I getting the error
java.lang.UnsatisfiedLinkError: Error looking up function 'FuncA': The specified procedure could not be found.

---

Reply to this email directly or view it on GitHub:
#65 (comment)

from jna.

yes, dependency walker shows the following in the function column:

class SomeClass & SomeClass::operator=(class SomeClass const &)
void FuncA(unsigned short,unsigned char *,unsigned char *)
int FuncB(unsigned char *,unsigned char *)

Let me check with the one who wrote the DLL to see if they used 'extern "C"'.

Will update this as soon as I hear from them

from jna.

not sure if it answers your questions, but on Dedendency Walker,

Without undecorate C++ functions, it has:

??4SomeClass@@QAEAAV0@ABV0@@z
?FuncA@@YAXGPAE0@Z
?FuncB@@YAHPAE0@Z

With undecorate C++ functions, it has:

class SomeClass & SomeClass::operator=(class SomeClass const &)
void FuncA(unsigned short,unsigned char *,unsigned char *)
int FuncB(unsigned char *,unsigned char *)

I'm waiting for the DLL writer's reply, and will update this as soon as I hear from them.

from jna.

Update: The DLL is updated. now I am not getting the error anymore, but I am not getting any output.

dll exported function: int FuncB(unsigned char_, unsigned char_)

java: int FuncB (char[] input, char[] output).

code:
char[] output = new char[8]; // output has no more than 8 characters
char[] input = new char { 'x', 'x', 'x' };
int len = FuncB (input, output);

After FuncB is executed, output is just a blank char array, is it the DLL issue or I don't have the signature mapping correctly?

from jna.

Native unsigned char maps to java byte.

Java char maps to native wchar_t.

On Apr 13, 2012, at 6:45 PM, write2warriors wrote:

Update: The DLL is updated. now I am not getting the error anymore, but I am not getting any output.

dll exported function: int FuncB(unsigned char_, unsigned char_)

java: int FuncB (char[] input, char[] output).

code:
char[] output = new char[8]; // output has no more than 8 characters
char[] input = new char { 'x', 'x', 'x' };
int len = FuncB (input, output);

After FuncB is executed, output is just a blank char array, is it the DLL issue or I don't have the signature mapping correctly?

---

Reply to this email directly or view it on GitHub:
#65 (comment)

from jna.