The commit removes the three compile warning options from the individual project
files into the zlib.props globals (this should probably be renamed in 1.7). It
increases the warning level from 4 to All and adds a list of the warnings which
need to be turned off. This is semi-documentary; the intent is to tell users of
libpng which warnings have been examined and judged non-fixable at present.
The warning about structure padding *IS* fixable, but it is a signficant change
(moving structure members around). It is currently partially fixed in 1.7, but
only partially.
Signed-off-by: John Bowler <jbowler@acm.org>
by earlier versions of GCC fixed for Cygwin and Min/GW (which both use old GCCs.)
ARM support is enabled by default in zlib.props (unsupported by Microsoft) and
ARM compilation is made possible by deleting the check for x86. The test programs
cannot be run because they are not signed.
The Try/Catch blocks were checking that the context had not changed -
unnecessary and cexcept cannot handle separate (potentially interleaved)
contexts anyway. Changed the code to make the Catch re-instate the context -
this should help the compiler because the context is the png_store and
minimising the need for the compiler to avoid optimizing it away is good.
The changes include support for function attributes in VC in addition to
those already present in GCC - necessary because without these some
warnings are unavoidable. Fixes include signed/unsigned fixes in
pngvalid and checks with gcc -Wall -Wextra -Wunused.
VC requires function attributes on function definitions as well as
declarations, PNG_FUNCTION has been added to enable this and the
relevant function definitions changed.
