digitalmars.D - D's exact stack convention for D and C/C++
- Adam Sansier (33/33) Jul 16 2016 I am trying to debug some really messed up code that makes no
- Joakim (13/46) Jul 16 2016 According to the spec,
- Guillaume Piolat (7/12) Jul 17 2016 If you don't use naked asm, you won't have to know this. And you
- bitwise (16/49) Jul 17 2016 Is this a member function or global function that you're talking
I am trying to debug some really messed up code that makes no sense. It calls in some code that doesn't seem to be using the standard calling convention. The function definitions are exactly the same in both D and C++. ->func(param1, param2, param3, param4); The call stack setup by C++ before the call is 001fa18d 002aff3c 00000014 000000c0 002b10f8 00c7fa34 001f16cc 7f383000 The order is ret EIP, param1, param2, param3, param4, this For D(naked asm) 00403ff3 002dc108 000000c0 00000014 002e73e8 026236f0 02ae4a78 0019fe54 The order is ret EIP, param4, param3, param2, param1, as one can see, the order is reversed. The functions are declared exactly the same in C++ and D(I just copied to D and marked extern(C++). It is part of a method(It is COM but that shouldn't matter?)). Forget all that, What I'm really interested in is the exact calling conventions used in D and C and C++ and what they mean so I can make sure I know whats going on, cause something funky is happening and it's not on my end(I'm not messing with the order of this stuff directly). So, extern(C) = ? extern(D) = ? extern(C++) = ? extern(Windows) = ? C++ standard convention = ? C standard convetion = ? D standard convention = ? Also, how is this pointer passed in method calls? ECX? Stack? If Stack, first or last? Does it change with calling convention? I'm looking for only the facts, hopefully from the man himself.
Jul 16 2016
Joakim <dlang joakim.fea.st> On Sunday, 17 July 2016 at 01:30:31 UTC, Adam Sansier wrote:I am trying to debug some really messed up code that makes no sense. It calls in some code that doesn't seem to be using the standard calling convention. The function definitions are exactly the same in both D and C++. ->func(param1, param2, param3, param4); The call stack setup by C++ before the call is 001fa18d 002aff3c 00000014 000000c0 002b10f8 00c7fa34 001f16cc 7f383000 The order is ret EIP, param1, param2, param3, param4, this For D(naked asm) 00403ff3 002dc108 000000c0 00000014 002e73e8 026236f0 02ae4a78 0019fe54 The order is ret EIP, param4, param3, param2, param1, as one can see, the order is reversed. The functions are declared exactly the same in C++ and D(I just copied to D and marked extern(C++). It is part of a method(It is COM but that shouldn't matter?)). Forget all that, What I'm really interested in is the exact calling conventions used in D and C and C++ and what they mean so I can make sure I know whats going on, cause something funky is happening and it's not on my end(I'm not messing with the order of this stuff directly). So, extern(C) = ? extern(D) = ? extern(C++) = ? extern(Windows) = ? C++ standard convention = ? C standard convetion = ? D standard convention = ? Also, how is this pointer passed in method calls? ECX? Stack? If Stack, first or last? Does it change with calling convention? I'm looking for only the facts, hopefully from the man himself.According to the spec, "The extern (C) and extern (D) calling convention matches the C calling convention used by the supported C compiler on the host system." https://dlang.org/spec/abi.html There are tests for C and C++ compatibility that you can look at, from the compiler testsuite: https://github.com/dlang/dmd/blob/master/test/runnable/cpp_abi_tests.d https://github.com/dlang/dmd/blob/master/test/runnable/cppa.d https://github.com/dlang/dmd/blob/master/test/runnable/cabi1.d The corresponding C/C++ files can be found here: https://github.com/dlang/dmd/tree/master/test/runnable/extra-files
Jul 16 2016
On Sunday, 17 July 2016 at 01:30:31 UTC, Adam Sansier wrote:Forget all that, What I'm really interested in is the exact calling conventions used in D and C and C++ and what they mean so I can make sure I know whats going on, cause something funky is happening and it's not on my end(I'm not messing with the order of this stuff directly).If you don't use naked asm, you won't have to know this. And you get other benefits like being able to use the same x86 code across OSes (and sometimes across x86 and x86_64). The problem with calling conventions is that they can be sublty different eg. between OS X and Linux 64-bit. It's a big trap that is worth avoiding.
Jul 17 2016
On Sunday, 17 July 2016 at 01:30:31 UTC, Adam Sansier wrote:I am trying to debug some really messed up code that makes no sense. It calls in some code that doesn't seem to be using the standard calling convention. The function definitions are exactly the same in both D and C++. ->func(param1, param2, param3, param4); The call stack setup by C++ before the call is 001fa18d 002aff3c 00000014 000000c0 002b10f8 00c7fa34 001f16cc 7f383000 The order is ret EIP, param1, param2, param3, param4, this For D(naked asm) 00403ff3 002dc108 000000c0 00000014 002e73e8 026236f0 02ae4a78 0019fe54 The order is ret EIP, param4, param3, param2, param1, as one can see, the order is reversed. The functions are declared exactly the same in C++ and D(I just copied to D and marked extern(C++). It is part of a method(It is COM but that shouldn't matter?)). Forget all that, What I'm really interested in is the exact calling conventions used in D and C and C++ and what they mean so I can make sure I know whats going on, cause something funky is happening and it's not on my end(I'm not messing with the order of this stuff directly). So, extern(C) = ? extern(D) = ? extern(C++) = ? extern(Windows) = ? C++ standard convention = ? C standard convetion = ? D standard convention = ? Also, how is this pointer passed in method calls? ECX? Stack? If Stack, first or last? Does it change with calling convention? I'm looking for only the facts, hopefully from the man himself.Is this a member function or global function that you're talking about? If you mean that you made a D class and then marked the function extern(C++), I don't believe that is the correct way to do it. You need to use an interface instead of a class in D, as described here: https://dlang.org/spec/cpp_interface.html I'm not sure if it has been fixed at this point, but classes with virtual destructors were not working for me last time I used this stuff. If it's a global function, then you could try changing it to extern(C) instead, and your mark your C++ functions extern"C". extern(C++) seemed to be giving me compiler-dependant difficulties last time I tried it. Bit
Jul 17 2016