Using Ruby /DL to invoke function in windows dll
in [Ruby]
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From: di vi on 10 Feb 2010 10:10 Hi, I have a C++ code converted into a windows Dll.I want to use Ruby /DL to invoke the functions in the DLL. Here are the function prototypes: C++ code [code] // MathFuncsDll.h namespace MathFuncs { class MyMathFuncs { public: // Returns a + b static __declspec(dllexport) double Add(double a, double b); // Returns a - b static __declspec(dllexport) double Subtract(double a, double b); // Returns a * b static __declspec(dllexport) double Multiply(double a, double b); // Returns a / b // Throws DivideByZeroException if b is 0 static __declspec(dllexport) double Divide(double a, double b); }; } [/code] Ruby code [code] require 'dl/import' module MATHFUN extend DL::Importable dlload "math funcs.dll" extern "double Add(double a, double b)" #extern "int strlen(const char *)" end MATHFUN.Add(5,4) [/code] Gives me an error saying undefined symbol. -- Posted via http://www.ruby-forum.com/.
From: Aaron Patterson on 10 Feb 2010 14:43 On Thu, Feb 11, 2010 at 12:10:20AM +0900, di vi wrote: > Hi, > > I have a C++ code converted into a windows Dll.I want to use Ruby /DL to > invoke the functions in the DLL. C++ code? Unless you know how to munge your functions the same way your compiler does, I don't think you're going to get very far. -- Aaron Patterson http://tenderlovemaking.com/
From: Albert Schlef on 10 Feb 2010 16:07 di vi wrote: > Hi, > > I have a C++ code converted into a windows Dll. [...] > require 'dl/import' > module MATHFUN > extend DL::Importable > dlload "math funcs.dll" > extern "double Add(double a, double b)" There are some utility programs that let you look into a library and see the symbols exposed. This way you see how the compiler mangled them. For example, in linux you can do `nm -D library.so`. Or create some 'extern "C"' wrapper functions for your methods. -- Posted via http://www.ruby-forum.com/.
From: Albert Schlef on 10 Feb 2010 16:11 Albert Schlef wrote: > There are some utility programs that let you look into a library and see > the symbols exposed. This way you see how the compiler mangled them. (It goes without saying that if you distribute your source code, somebody may use a compiler which mangles the names differently and your ruby/dl won't see them anymore.) -- Posted via http://www.ruby-forum.com/.
From: di vi on 10 Feb 2010 23:30
Albert Schlef wrote: > Albert Schlef wrote: >> There are some utility programs that let you look into a library and see >> the symbols exposed. This way you see how the compiler mangled them. > > (It goes without saying that if you distribute your source code, > somebody may use a compiler which mangles the names differently and your > ruby/dl won't see them anymore.) I used PE explorer and saw the dill in disassembler.Attached is the picture showing its names.Please advice. Attachments: http://www.ruby-forum.com/attachment/4469/dll_debug1.JPG -- Posted via http://www.ruby-forum.com/. |