unifdef: use memcpy instead of strncpy

New versions of gcc reasonably warn about the odd pattern of

strncpy(p, q, strlen(q));

which really doesn't make sense: the strncpy() ends up being just a slow
and odd way to write memcpy() in this case.

There was a comment about _why_ the code used strncpy - to avoid the
terminating NUL byte, but memcpy does the same and avoids the warning.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

unifdef: update to upstream version 2.5

Fix a long-standing cpp compatibility bug. The -DFOO argument
(without an explicit value) should define FOO to 1 not to the empty
string.

Add a -o option to support overwriting a file in place, and a -S
option to list the nesting depth of symbols. Include line numbers
in debugging output. Support CRLF newlines.

Signed-off-by: Tony Finch <dot@dotat.at>
Signed-off-by: Michal Marek <mmarek@suse.cz>

unifdef: update to upstream revision 1.190

Fix handling of input files (e.g. with no newline at EOF) that could
make unifdef get into an unexpected state and call abort().

The new -B option compresses blank lines around a deleted section
so that blank lines around "paragraphs" of code don't get doubled.

The evaluator can now handle macros with arguments, and unbracketed
arguments to the "defined" operator.

Add myself to MAINTAINERS for unifdef.

Signed-off-by: Tony Finch <dot@dotat.at>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>

kbuild: fix headers_exports with boolean expression

When we had code like this in a header unifdef failed to
deduct that the expression was always false - and we had code exported
that was not intended for userspace.

#if defined(__KERNEL__) && !defined(__ASSEMBLY__)
int a;
#endif

This commit implment support in unidef which allows it to work out if
an #if expression always evaluates true or false for symbols which
are being undefined/always defined.

The patch is slightly more complicated than I'd hoped because unifdef
needs to see lines fully evaluated - doing otherwise causes it to
mark the line as "dirty" and copy it over no matter what.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

kbuild: fix C libary confusion in unifdef.c due to getline()

This fixes an error when compiling the kernel.

CHK include/linux/version.h
HOSTCC scripts/unifdef
scripts/unifdef.c:209: error: conflicting types for 'getline'
/usr/include/stdio.h:651: note: previous declaration of 'getline' was here
make[1]: *** [scripts/unifdef] Error 1
make: *** [__headers] Error 2

Signed-off-by: Justin P. Mattock <justinmattock@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

kbuild: replace use of strlcpy with a dedicated implmentation in unifdef

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

kbuild: add unifdef

This patch contains a raw copy of unifdef.c
Next patch will modify it and add infrastructure to use it
Adding unifdef to the kernel is acked by the author.

The reason to add unifdef as part of the kernel source is that it is not
yet a common utility on most distributions.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>