Compilation strategy

[foobar]

On Monday, 17 December 2012 at 22:24:00 UTC, Walter Bright wrote:
> On 12/17/2012 2:08 PM, Dmitry Olshansky wrote:
>> I really loved the way Turbo Pascal units were made. I wish D 
>> go the same
>> route.  Object files would then be looked at as minimal and 
>> stupid variation of
>> module where symbols are identified by mangling (not plain 
>> meta data as (would
>> be) in module) and no source for templates is emitted.
>> +1
>
> I'll bite. How is this superior to D's system? I have never 
> used TP.
>
>
>> *Semantic info on interdependency of symbols in a source file 
>> is destroyed right
>> before the linker and thus each .obj file is included as a 
>> whole or not at all.
>> Thus all C run-times I've seen _sidestep_ this by writing each 
>> function in its
>> own file(!). Even this alone should have been a clear 
>> indication.
>
> This is done using COMDATs in C++ and D today.

Honest question - If D already has all the semantic info in 
COMDAT sections, why do we still require additional auxiliary 
files? Surely, a single binary library (lib/so) should be enough 
to encapsulate a library without the need to re-parse the source 
files or additional header files?

You yourself seem to agree that a single zip file is superior to 
what we currently have and as an aside the entire Java community 
agrees with use - Java Jar/War/etc formats are all renamed zip 
archives.

Regarding the obfuscation and portability issues - the zip file 
can contain whatever we want. This means it should be possible to 
tailor the contents to support different use-cases:
  * provide fat-libraries as in OSX - internally store multiple 
binaries for different architectures, those binary objects are 
very hard to decompile back to source code thus answering the 
obfuscation need.
  * provide a byte-code solution to support the portability case. 
e.g Java byte-code or Google's pNaCL solution that relies on LLVM 
bit-code.

Also, there are different work-flows that can be implemented - 
Java uses JIT to gain efficiency vs. .NET that supports 
install-time AOT compilation. It basically stores the native 
executable in a special cache.