llvm dev - Aug 2006 - [LLVMdev] updating the "Getting Started" page with more info about the gcc4 frontend

Devang Patel wrote:
> 
> On Aug 23, 2006, at 7:00 PM, Emil Mikulic wrote:
> 
>> Where -is- that documented?
>>
>> The only reason I know about it is because of how many times it's
come
>> up on the list.  =)
> 
> http://llvm.org/docs/GettingStarted.html ?
> 
> ...
> Example with llvm-gcc4
> First, create a simple C file, name it 'hello.c':
>   #include <stdio.h>
>   int main() {
>     printf("hello world\n");
>     return 0;
>   }
> 
> Next, compile the C file into a native executable:
That part about "native" -- yeah, it's there. The existence
predicate
returns true. IT'S SOMETHING THAT IS EASILY SKIPPED OVER WHEN SKIMMING
THE DOCUMENT BECAUSE, HECK, THE GCC3 DRIVER COMPILES DIRECTLY TO
BYTECODE SO WHY DOESNT GCC4?

It's a "least surprise" issue. If gcc3 produces bytecode directly,
why
did the gcc4 driver create such a large departure from original,
expected functionality? It's a rhetorical question, BTW.

Scott Michel wrote:
> That part about "native" -- yeah, it's there. The existence
predicate
> returns true. IT'S SOMETHING THAT IS EASILY SKIPPED OVER WHEN SKIMMING
> THE DOCUMENT BECAUSE, HECK, THE GCC3 DRIVER COMPILES DIRECTLY TO
> BYTECODE SO WHY DOESNT GCC4?
>
> It's a "least surprise" issue. If gcc3 produces bytecode
directly, why
> did the gcc4 driver create such a large departure from original,
> expected functionality? It's a rhetorical question, BTW.
>   
I actually know this one :) I believe the powers that be decided that 
having a gcc-compatible interface was less surprising to folks than 
keeping compatible with the gcc3 driver. Thats why the gcc4 driver now 
supports the whole -O[1-4] options, among other things.

Erick Tryzelaar wrote:
>> It's a "least surprise" issue. If gcc3 produces bytecode
directly, why
>> did the gcc4 driver create such a large departure from original,
>> expected functionality? It's a rhetorical question, BTW.
>>   
> 
> I actually know this one :) I believe the powers that be decided that
> having a gcc-compatible interface was less surprising to folks than
> keeping compatible with the gcc3 driver. Thats why the gcc4 driver now
> supports the whole -O[1-4] options, among other things.
That's why I would either make sure that the difference is highlighted
in the FAQ and that the difference is highlighted in the "Getting
Started" pages. Otherwise, it'll remain a mailing list FAQ.