[U-Boot-Users] [PATCH] tools/envcrc.c: use the target sizeof rather than build

[Wolfgang Denk]

In message <1206908872-2141-1-git-send-email-vapier at gentoo.org> you wrote:
> The envcrc.c does sizeof(unsigned long) when calculating the crc, but this
> is done with the build toolchain instead of the target toolchain, so if
> the build is a 64bit system but the target is 32bits, the size will
> obviously be wrong.  This introduces a sizeof.sh script to calculate the
> required sizeof() value of any type with any compiler.

It seems this script requires up to 64 runs  of  the  C  compiler.  I
consider this pretty expensive. Isn't there a cheaper way to do that?

Consider the simple logic used to decide between 32 versus 64 bit
pointer types - shouldn't this be sufficient here, too?

> --- /dev/null
> +++ b/tools/sizeof.sh
> @@ -0,0 +1,35 @@
> +#!/bin/sh
> +# Get the sizeof(type) for a compiler
> +
> +type="$*"
> +CC=${CC:-gcc}
> +
> +if [ -z "$type" ] ; then
> +	echo "Usage: sizeof.sh <type>" 1>&2
> +	exit 1
> +fi
> +
> +test_size() {
> +	cat <<-EOF > sizeof.c
> +	typedef $type ac__type_sizeof_;
> +	int main() {
> +		static int test_array [1 - 2 * !(((long int) (sizeof (ac__type_sizeof_))) <= $size)];
> +		test_array [0] = 0;
> +		return 0;
> +	}
> +	EOF
> +	${CC} -c sizeof.c >/dev/null 2>&1
> +	ret=$?
> +	rm -f sizeof.[co]
> +	return $ret
> +}

Are there no Copyrights / License conditions attached to  this  code?
Where exactly is it coming from?


Best regards,

Wolfgang Denk

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