4 ms·

What is cause, what is effect? "All" languages (which survived) can call into C.

by johannes1234321 5y ago

GoblinSlayer 5y ago
C can call into Pascal too. Does it mean libraries should use pascal strings in their interface?
- johannes1234321 5y ago
  i'm not seeing where i can configure gcc to use pascal calling conventions. looking at https://gcc.gnu.org/onlinedocs/gcc/x86-Function-Attributes.html https://gcc.gnu.org/onlinedocs/gcc/x86-Function-Attributes.h... And yes, with common Pascal compilers i can write specific functions in a way to provide a C calling interface (called STDCALL) so those functions can be called from C. But for reaching arbitrary Pascal functions I need my own assembly code which passes parameters in the right order and manages the stack "correctly" (in C the caller clears the stack, in Pascal the calleé)
  - Joker_vD 5y ago
    ...the calling conventions are not the properties of the language itself, or the OS, only of the langauge implementations — the Gnu Pascal Compiler uses the same calling convention as the Gnu C Complier [0], so I think GCC simply decided not to support any other Pascal implementation explicitly and left those to figure out themselves how to link with object files produced by GCC. And yes, generally different implementations of the same language tended to use the same calling conventions to be compatible/interoperable with each other in the first place, although it's not a universal rule, so that's how why x86 calling conventions were labeled with PL names; but that's slight misnomering. On x64 Linux, everyone managed to agree to use the same calling convention which is of course very convenient. The language of it's written specification is heavily C-biased, but if you squint you can see that it talks mostly about eightbytes and and compound objects and where to shove those so it more or less trivially translates to most other Algol- or C-descendant imperative languages; I believe it can even be reformulated strictly in language-neutral/assembly terms. On vanilla x86, of course, everyone invented their own calling convention, even different implementations of the same languages: IIRC, Borland C++, MSVC, Watcom, and GCC on Windows all by default produced object files that you could not simply link together without manual tinkering. And (32-bit) Windows, despite being written in C, uses a variation of "Pascal" calling convention in its system API which they called "stdcall". I believe there were some C compilers that actually used "stdcall" by default instead of "cdecl". Hell, even on x64, Cygwin GCC (on Windows) uses SysV ABI for everything except interfacing with Windows itself where it obviously has to use Windows x64 calling convention. [0] http://www.gnu-pascal.de/gpc/Importing-Libraries-from-Other-Languages.html http://www.gnu-pascal.de/gpc/Importing-Libraries-from-Other-...

What is cause, what is effect? "All" languages (which survived) can call into C.

GoblinSlayer 5y ago

C can call into Pascal too. Does it mean libraries should use pascal strings in their interface?

johannes1234321 5y ago
i'm not seeing where i can configure gcc to use pascal calling conventions. looking at https://gcc.gnu.org/onlinedocs/gcc/x86-Function-Attributes.html https://gcc.gnu.org/onlinedocs/gcc/x86-Function-Attributes.h... And yes, with common Pascal compilers i can write specific functions in a way to provide a C calling interface (called STDCALL) so those functions can be called from C. But for reaching arbitrary Pascal functions I need my own assembly code which passes parameters in the right order and manages the stack "correctly" (in C the caller clears the stack, in Pascal the calleé)
- Joker_vD 5y ago
  ...the calling conventions are not the properties of the language itself, or the OS, only of the langauge implementations — the Gnu Pascal Compiler uses the same calling convention as the Gnu C Complier [0], so I think GCC simply decided not to support any other Pascal implementation explicitly and left those to figure out themselves how to link with object files produced by GCC. And yes, generally different implementations of the same language tended to use the same calling conventions to be compatible/interoperable with each other in the first place, although it's not a universal rule, so that's how why x86 calling conventions were labeled with PL names; but that's slight misnomering. On x64 Linux, everyone managed to agree to use the same calling convention which is of course very convenient. The language of it's written specification is heavily C-biased, but if you squint you can see that it talks mostly about eightbytes and and compound objects and where to shove those so it more or less trivially translates to most other Algol- or C-descendant imperative languages; I believe it can even be reformulated strictly in language-neutral/assembly terms. On vanilla x86, of course, everyone invented their own calling convention, even different implementations of the same languages: IIRC, Borland C++, MSVC, Watcom, and GCC on Windows all by default produced object files that you could not simply link together without manual tinkering. And (32-bit) Windows, despite being written in C, uses a variation of "Pascal" calling convention in its system API which they called "stdcall". I believe there were some C compilers that actually used "stdcall" by default instead of "cdecl". Hell, even on x64, Cygwin GCC (on Windows) uses SysV ABI for everything except interfacing with Windows itself where it obviously has to use Windows x64 calling convention. [0] http://www.gnu-pascal.de/gpc/Importing-Libraries-from-Other-Languages.html http://www.gnu-pascal.de/gpc/Importing-Libraries-from-Other-...