[U-Boot] [PATCH] Avoid using gawk-specific strtonum()

[Måns Rullgård]

Tom Rini <trini at ti.com> writes:

> On Wed, Jun 18, 2014 at 12:01:12PM +0200, Wolfgang Denk wrote:
>
>> Dear Simon,
>> 
>> In message <1403071815-32055-1-git-send-email-sjg at chromium.org> you wrote:
>> > We need to subtract two hex numbers. Avoid using strtonum() by doing the
>> > subtraction in bc with a suitable input base.
>> > 
>> > Signed-off-by: Simon Glass <sjg at chromium.org>
>> > Reported-by: Vasili Galka <vvv444 at gmail.com>
>> > ---
>> > 
>> >  Makefile | 3 ++-
>> >  1 file changed, 2 insertions(+), 1 deletion(-)
>> > 
>> > diff --git a/Makefile b/Makefile
>> > index 24d9687..bb2f615 100644
>> > --- a/Makefile
>> > +++ b/Makefile
>> > @@ -788,7 +788,8 @@ OBJCOPYFLAGS_u-boot.bin := -O binary
>> >  binary_size_check: u-boot.bin System.map FORCE
>> >  	@file_size=`stat -c %s u-boot.bin` ; \
>> >  	map_size=$(shell cat System.map | \
>> > -		awk '/_image_copy_start/ {start = $$1} /_image_binary_end/ {end = $$1} END {if (start != "" && end != "") print strtonum("0x" end) - strtonum("0x" start)}'); \
>> > +		awk '/_image_copy_start/ {start = $$1} /_image_binary_end/ {end = $$1} END {if (start != "" && end != "") print "ibase=16; " toupper(end) " - " toupper(start)}' \
>> > +		| bc); \
>> 
>> I think instead of introducing yet another tool dependency this could
>> be rewritten to use just bash:
>> 
>> 	awk '/_image_copy_start/ {start = $1}
>> 	     /_image_binary_end/ {end = $1}
>> 	     END { if (start != "" && end != "")
>> 	     	print "printf %d $$((0x" end " - 0x" start "))"
>> 	     }' |
>> 	bash
>
> But now we're forcing bash.

Arithmetic expansion including hex constants is POSIX shell:
http://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_06_04

-- 
Måns Rullgård
mans at mansr.com