Re: [HACKERS] Custom compression methods (mac+lz4.h)

Justin Pryzby <pryzby(at)telsasoft(dot)com> writes:
> On Fri, Mar 19, 2021 at 02:07:31PM -0400, Robert Haas wrote:
>> On Fri, Mar 19, 2021 at 1:44 PM Justin Pryzby <pryzby(at)telsasoft(dot)com> wrote:
>>> configure: WARNING: lz4.h: accepted by the compiler, rejected by the preprocessor!
>>> configure: WARNING: lz4.h: proceeding with the compiler's result

>> No, I don't see this. I wonder whether this could possibly be an
>> installation issue on Andrey's machine? If not, it must be
>> version-dependent or installation-dependent in some way.

> Andrey, can you check if latest HEAD (bbe0a81db) has these ./configure warnings ?

FWIW, I also saw that, when building HEAD against MacPorts' version
of liblz4 on an M1 Mac. config.log has

configure:13536: checking lz4.h usability
configure:13536: ccache clang -c -I/opt/local/include -Wall -Wmissing-prototype\
s -Wpointer-arith -Wdeclaration-after-statement -Werror=vla -Wendif-labels -Wmi\
ssing-format-attribute -Wformat-security -fno-strict-aliasing -fwrapv -Wno-unus\
ed-command-line-argument -g -O2 -isysroot /Applications/Xcode.app/Contents/Deve\
loper/Platforms/MacOSX.platform/Developer/SDKs/MacOSX11.1.sdk conftest.c >&5
configure:13536: $? = 0
configure:13536: result: yes
configure:13536: checking lz4.h presence
configure:13536: ccache clang -E -isysroot /Applications/Xcode.app/Contents/Dev\
eloper/Platforms/MacOSX.platform/Developer/SDKs/MacOSX11.1.sdk conftest.c
conftest.c:67:10: fatal error: 'lz4.h' file not found
#include <lz4.h>
^~~~~~~
1 error generated.
configure:13536: $? = 1

Digging around, it looks like the "-I/opt/local/include" bit came
from LZ4_CFLAGS, which we then stuck into CFLAGS, but it needed
to be put in CPPFLAGS in order to make this test work.

regards, tom lane