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D.gnu - d symbol information (the things c gets from headers)

reply Jakob Praher <jpraher yahoo.de> writes:
hi all,

I am new to do D, but have some experience with C/Java/Oberon systems.

if you want to use a lib from c, you have the header files and use the 
symbol information therein to link against that.
in java for instance, you have the class file which has the meta 
information built into the intermediate representation, so the linker 
information can deduce the linkage information right out of the .class fie.
in oberon you have symbol lists that are only needed for compiling, like 
binary header files.

how does d, which abandonds header files too, does linking, for 
instance, if you have a d shared object:

foo.d:

class World {

void hello( ) {
	printf( "hello from 'foo'\n" );
}
}

you compile that to a shared object file.

then you have
bar.d

import foo;

int main( char[][] args ) {
    World w = new World( );
    w.hello( );
}



how does the compilation model look like?
how do you embed the information into elf? (using dwarf2/3)?
do you require source distributions?

thaks
-- Jakob
Apr 30 2004
parent reply Andy Friesen <andy ikagames.com> writes:
Jakob Praher wrote:


 hi all,
 
 I am new to do D, but have some experience with C/Java/Oberon systems.
 
 if you want to use a lib from c, you have the header files and use the 
 symbol information therein to link against that.
 in java for instance, you have the class file which has the meta 
 information built into the intermediate representation, so the linker 
 information can deduce the linkage information right out of the .class fie.
 in oberon you have symbol lists that are only needed for compiling, like 
 binary header files.
 
 how does d, which abandonds header files too, does linking, for 
 instance, if you have a d shared object:
 
 how does the compilation model look like?
 how do you embed the information into elf? (using dwarf2/3)?
 do you require source distributions?


Sort of.  D uses the actual source file to import.  The difference is 
that, when you import, D doesn't actually care about the definitions, 
just the declarations, so you can leave that all out.  The result looks 
like a header file:

For instance, you might distribute a foo.d that looks like this:

     class World {
         void hello();
     }

The compilation model used in current compilers is pretty much identical 
to the C model, though there is nothing in the spec that would prevent 
someone from coming up with a different one.

  -- andy
Apr 30 2004
next sibling parent "C. Sauls" <ibisbasenji yahoo.com> writes:
Andy Friesen wrote:

 For instance, you might distribute a foo.d that looks like this:
 
     class World {
         void hello();
     }


And I'd just like to add that you'd only expose public citizens of the 
module.. for instance the module:

------------------------------
module foo;

private import std.stream;

class World {
public:
   void hello() {
     stdout.writeString("Hello");
     _world();
   }
private:
   void _world() {
     stdout.writeString(" world.\n");
   }
}
------------------------------

Would be distributed looking like:

------------------------------
module foo;

class World {
   void hello();
}
------------------------------

-C. Sauls
-Invironz
Apr 30 2004
prev sibling parent Jakob Praher <jpraher yahoo.de> writes:
Andy Friesen wrote:

 Jakob Praher wrote:
 

 hi all,

 I am new to do D, but have some experience with C/Java/Oberon systems.

 if you want to use a lib from c, you have the header files and use the 
 symbol information therein to link against that.
 in java for instance, you have the class file which has the meta 
 information built into the intermediate representation, so the linker 
 information can deduce the linkage information right out of the .class 
 fie.
 in oberon you have symbol lists that are only needed for compiling, 
 like binary header files.

 how does d, which abandonds header files too, does linking, for 
 instance, if you have a d shared object:

 how does the compilation model look like?
 how do you embed the information into elf? (using dwarf2/3)?
 do you require source distributions?


 
 
 Sort of.  D uses the actual source file to import.  The difference is 
 that, when you import, D doesn't actually care about the definitions, 
 just the declarations, so you can leave that all out.  The result looks 
 like a header file:
 
 For instance, you might distribute a foo.d that looks like this:
 
     class World {
         void hello();
     }
 
 The compilation model used in current compilers is pretty much identical 
 to the C model, though there is nothing in the spec that would prevent 
 someone from coming up with a different one.


thanks for the info.

would be interesting to distribute the declarations in dwarf2/3 format. 
in a special section, or as a separate file. And if this binary 
information is not there, the compiler searches for d source files.

-- Jakob
Apr 30 2004