[Scons-users] rebuilding

[Evan Driscoll]

On 06/26/2012 10:07 AM, TOM TANNER (BLOOMBERG/ LONDON) wrote:

> Ah, yes, that's the problem. I'll have a look at using RPATH - aix linker doesn't have an equivalent and you have to use -L to make the executable pick libraries up from the right place...


So I'm not an SCons dev, but my initial reaction is that either of the 
following fixes seems reasonable:

- Change env["_LIBDIRFLAGS"] so that, for the Aix linker, it leaves in
   $( $)

- Change env["RPATHPREFIX"] to be "-L" (by default, "-Wl,-rpath=")
   and then use env["RPATH"] to add stuff.

The latter approach has the advantage that you can just use env["RPATH"] 
across systems (well, any systems that behave like Linux and, after your 
fix, Aix :-)) to set the runtime lookup paths, but has the disadvantage 
that env["RPATH"] and env["LIBPATH"] now do the same thing.

Evan




>

> ----- Original Message -----

> From: scons-users at scons.org

> To: scons-users at scons.org

> At:  6/26 15:31:24

>

> [If you get this twice, I apologize]

>

> On Tuesday, June 26, 2012 08:24:36 AM TOM TANNER wrote:

>> relinks then. but it should have caused a lot of them, not zero.

>

> Actually, with a little prompting, I'd only have expected relinks if adding

> the directory caused a different library to get picked up.

>

> And here's why that happens:

>

> The default LINKCOM (Linux) is

>   $LINK -o $TARGET $LINKFLAGS $__RPATH $SOURCES $_LIBDIRFLAGS $_LIBFLAGS

>

> _LIBDIRFLAGS is where the -L flags are included, programatically builtup from

> LIBDIRS:

>     $( ${_concat(LIBDIRPREFIX, LIBPATH, LIBDIRSUFFIX, __env__, RDirs,

>                          TARGET, SOURCE)} $)

>

> The $( and $) say omit the stuff that comes in here from a file's signature (the

> thing that causes it something to rebuild if it changes). It's unnecessary

> because the library files are found independently by SCons anyway so that it

> can take the MD5 hash (or look at the timestamp, or Decide however) so if the

> libraries change it will rebuild.

>

> Evan

>

>

>

>>

>> ----- Original Message -----

>> From: scons-users at scons.org

>> To: scons-users at scons.org

>> At:  6/26 13:23:17

>>

>> On Jun 26, 2012 2:15 PM, "TOM TANNER (BLOOMBERG/ LONDON)"<

>> ttanner2 at bloomberg.net>  wrote:

>>

>>>

>>>

>>> I was slightly surprised not to get anything rebuilt when I added a

>>

>> directory to my env['LIBPATH'].

>>

>>>

>>>

>>> Surely this should cause a load of rebuilds?.

>>>

>>>

>>

>>

>> Relinks surely, rebuilds not so certain...

>>

>> JB _______________________________________________

>>

>>> Scons-users mailing list

>>> Scons-users at scons.org

>>> http://four.pairlist.net/mailman/listinfo/scons-users

>>

>>

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