qtwebengine ports no longer configure with MacPorts’ re2

[chrstphrchvz (Christopher Chavez)]

The ports for qtwebengine 5.13 and 5.15 depend on MacPorts’ re2, but the configure test fails due to re2 now requiring Abseil which requires C++14, and so -std=gnu++11 (presumably a default flag from qmake) as used by the configure test is not allowed.

--->  Configuring qt5-qtwebengine
Executing:  cd "/opt/local/var/macports/build/_opt_local_var_macports_sources_github.com_macports_macports-ports_aqua_qt5/qt5-qtwebengine/work/qtwebengine-5.15.14-lts" && /opt/local/libexec/qt5/bin/qmake PREFIX=/opt/local QMAKE_LINK=/usr/bin/clang++ -spec macx-clang -- -webengine-kerberos -webengine-proprietary-codecs -system-webengine-icu -system-webengine-ffmpeg -feature-webengine-system-gn 
Info: creating stash file /opt/local/var/macports/build/_opt_local_var_macports_sources_github.com_macports_macports-ports_aqua_qt5/qt5-qtwebengine/work/qtwebengine-5.15.14-lts/.qmake.stash

Running configuration tests...
[…]
Checking for re2... no
[…]
Qt WebEngine Build Tools:
[…]
  Optional system libraries used:
    re2 .................................. no

In config.log:

> /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ -c -pipe -stdlib=libc++ -O2 -std=gnu++11  -arch x86_64 -isysroot /Applications/Xcode.app/Contents/Developer/Platform
s/MacOSX.platform/Developer/SDKs/MacOSX13.1.sdk -mmacosx-version-min=10.13 -w -fPIC -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINM
AX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -
DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOM
INMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMA
X -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -DNOMINMAX -I
. -I/opt/local/libexec/qt5/mkspecs/macx-clang -o main.o main.cpp
> In file included from main.cpp:2:
> In file included from /opt/local/include/re2/filtered_re2.h:28:
> In file included from /opt/local/include/absl/strings/string_view.h:39:
> In file included from /opt/local/include/absl/base/attributes.h:37:
> In file included from /opt/local/include/absl/base/config.h:86:
> /opt/local/include/absl/base/policy_checks.h:79:2: error: "C++ versions less than C++14 are not supported."
> #error "C++ versions less than C++14 are not supported."

[chrstphrchvz (Christopher Chavez)]

To correct myself, qt6-qtwebengine is not affected by this (presumably since it uses C++17)

[kencu (Ken)]

They are certainly trying be super super sure that -DNOMINMAX gets defined ... :>

[mascguy (Christopher Nielsen)]

Adding Herby to the mix

[chrstphrchvz (Christopher Chavez)]

Replying to kencu:

They are certainly trying be super super sure that -DNOMINMAX gets defined ... :>

Presumably that is due to pkg-config --cflags re2 outputting seemingly identical flags from many of Abseil’s .pc files.

[chrstphrchvz (Christopher Chavez)]

So far I have not figured out how to influence CXXFLAGS and override -std=gnu++11 for the configuration tests, except for the -z noexecstack check which does pick up qt5.cxxflags-append -std=gnu++14.

This seems more like a situation for compiler_wrapper, but given the degree to which qmake is likely also controlling compiler selection, that might involve something like the approach in the (Qt4) qmake portgroup.