[csw-maintainers] setting *FLAGS?

[Dagobert Michelsen]

Hi Daniel,

Am 19.04.2012 um 16:06 schrieb Daniel Pocock:
> I notice there are many ways people set CXXFLAGS, LDFLAGS, etc from
> within mgar Makefiles
> 
> Let's say I want to use bdb, I notice several versions are available:
> 
> daniel at login [login]:~/opencsw/resiprocate/trunk > ls -d /opt/csw/bdb*
> /opt/csw/bdb4
> /opt/csw/bdb42
> /opt/csw/bdb44
> /opt/csw/bdb47
> /opt/csw/bdb48
> 
> Should I just do something like this?

The correct solution is
  BDB_HOME = $(prefix)/bdb48
  EXTRA_LIB = $(BDB_HOME)/lib 
  EXTRA_INC = $(BDB_HOME)/include

The main difference is that EXTRA_LIB propapages correctly to -L and -R
during LDFLAGS and LD_OPTIONS and additionally gets the 64 bit subdir
appended on 64 bit ISAs.

See here for an example:
  https://sourceforge.net/apps/trac/gar/browser/csw/mgar/pkg/openldap/trunk/Makefile#L132

> BDB_HOME = /opt/csw/bdb48
> BDB_INC = $(BDB_HOME)/include
> BDB_LIB = $(BDB_HOME)/lib
> 
> EXTRA_CFLAGS += -I$(BDB_INC)
> EXTRA_CXXFLAGS += -I$(BDB_INC)
> EXTRA_LINKER_FLAGS += -L$(BDB_LIB)

Usually you set the preprocessor flags
  EXTRA_CPPFLAGS += -I$(BDB_INC)
but CFLAGS and CXXFLAGS is also fine.

LINKER_FLAGS is essentially ok as it propagates to LDFLAGS and LD_OPTIONS:
  https://sourceforge.net/apps/trac/gar/browser/csw/mgar/gar/v2/gar.conf.mk#L693
However, it does not append 64 bit subdirectory and hence will fail if 64 bit
build is requested.

> Or should I set LDFLAGS directly?
> 
> LDFLAGS += -L$(BDB_LIB)

Setting LDFLAGS overwrites all flags regardless of the +=. If you want to add
something please always use
  EXTRA_LDFLAGS += -L$(BDB_LIB)

This is a general design principle of GAR: If you set <VAR> you overwrite it,
EXTRA_<VAR> adds the value to the default.


Best regards

  -- Dago

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