Erroneous "Stack size likely to be exceeded" make error when 'ulimit -s' returns "unlimited"

[fgvanzee]

After making three variable modifications to Makefile.rule:

BLAS_API = 1
FORTRAN_BLAS_API = 1
CBLAS_API = 1

of commit 78c3120, I run make and then receive the following error:

$ make
Parsing Makefile.rule
Makefile.rule:324: *** stack size likely to be exceeded, please decrease the value of K_MAX_STACK .  Stop.

Looking at Makefile.rule more closely, I find around line 321:

STACK_SIZE := $(shell ulimit -s)
STACK_SIZE_EXCEEDED := $(shell echo $(K_MAX_STACK)*12*8*2 \> $(STACK_SIZE)*1024 | bc )
ifeq ($(STACK_SIZE_EXCEEDED), 1)
$(error stack size likely to be exceeded, please decrease the value of K_MAX_STACK )
endif
CFLAGS  += -DK_MAX_STACK=$(K_MAX_STACK)

It appears that this code doesn't work properly when ulimit -s returns unlimited, as it does on my current Cray Linux Environment 6 system:

$ uname -a
Linux nid00019 4.4.103-6.38_4.0.95-cray_ari_c #1 SMP Fri Feb 9 17:52:44 UTC 2018 (172b90b) x86_64 x86_64 x86_64 GNU/Linux

I checked a previous version of BLASFEO that was working fine (2c9f312) and it appears that the code snippet above is new.

Commenting out the first five lines above (all except for update of CFLAGS) seems to allow the build system to finish normally.

[giaf]

Hi Field,
thanks for the bug report. The case of unlimited stack size is indeed not correctly handled, I will take care of it now.
For now you can simply comment out the 5 lines

STACK_SIZE := $(shell ulimit -s)
STACK_SIZE_EXCEEDED := $(shell echo $(K_MAX_STACK)*12*8*2 \> $(STACK_SIZE)*1024 | bc )
ifeq ($(STACK_SIZE_EXCEEDED), 1)
$(error stack size likely to be exceeded, please decrease the value of K_MAX_STACK )
endif

[giaf]

This should fix it f5ebb2d