[LLVMdev] LLVM_LIB_SEARCH_PATH

[Jeff Cohen]

Chris Lattner wrote:

> On Sun, 12 Dec 2004, Reid Spencer wrote:
>
>> Hello,
>>
>> I need to solicit your opinion about something.
>>
>> I'm toying with the idea of getting rid of LLVM_LIB_SEARCH_PATH. Right
>> now the linkers will use this environment variable if it specifies a
>> single directory. It will look in that directory to find libraries when
>> things like -lc or -lcrtend are specified on the command line. Right
>> now, the only known place this is useful to set to is the CFE's
>> install/bytecode-libs directory. However, the configure script can make
>> that path available to us already because LLVM requires configuring with
>> --with-llvmgccdir=...
>
>
> Actually, LLVM does *not* require the C frontend, but the only tools 
> that use the environment variable are those that are only used by the 
> CFE.
>
>> So, it is my understanding that current usage of
>> LLVM_LIB_SEARCH_PATH is redundant with already available information
>> from the configure script.
>>
>> Does anyone put anything *other* than CFE/install/bytecode-libs in their
>> LLVM_LIB_SEARCH_PATH? Does anyone expect it to actually be a colon
>> separated list of path names to be searched (its not interpreted that
>> way currently)?
>>
>> I see two options:
>>
>> 1. Get rid of LLVM_LIB_SEARCH_PATH and just have the linker "know"
>>   about the bytecode-libs directory if --with-llvmgccdir was
>>   specified to configure.
>>
>> 2. Fully support LLVM_LIB_SEARCH_PATH as a colon separated path list
>>   to search for bytecode archives and files. In this case their would
>>   be no need to specify the bytecode-libs directory, it would be
>>   included already.
>
>
> I definitely prefer #1.  The only concern I have with it is that this 
> makes it impossible to move the llvmgcc install directory once it is 
> built (tools would not look in the correct directories).
>
> -Chris
>
This is a very big concern.  Users of LLVM generally do not build 
llvmgcc -- are actively discouraged from building it -- and therefore 
would have no option as to where it must be installed on their system.