gtk4: build fails with gcc, due to use of '-export_dynamic'

[barracuda156]

:info:build FAILED: testsuite/gtk/builder 
:info:build /opt/local/bin/gcc-mp-12  -o testsuite/gtk/builder testsuite/gtk/builder.p/builder.c.o -L/opt/local/lib -I/opt/local/include -Wl,-dead_strip_dylibs -Wl,-headerpad_max_install_names -Wl,-undefined,error -Wl,-headerpad_max_install_names -lMacportsLegacySupport -arch ppc -pipe -Os -arch ppc -Wl,-rpath,@loader_path/../../gtk gtk/libgtk-4.1.dylib -Wl,-export_dynamic /opt/local/lib/libgmodule-2.0.dylib /opt/local/lib/libglib-2.0.dylib /opt/local/lib/libintl.dylib /opt/local/lib/libgobject-2.0.dylib /opt/local/lib/libgio-2.0.dylib /opt/local/lib/libpangocairo-1.0.dylib /opt/local/lib/libpango-1.0.dylib /opt/local/lib/libharfbuzz.dylib /opt/local/lib/libcairo.dylib /opt/local/lib/libfribidi.dylib /opt/local/lib/libcairo-gobject.dylib /opt/local/lib/libfontconfig.dylib /opt/local/lib/libfreetype.dylib /opt/local/lib/libgdk_pixbuf-2.0.dylib /opt/local/lib/libepoxy.dylib -lm /opt/local/lib/libgraphene-1.0.dylib /opt/local/lib/libXi.dylib /opt/local/lib/libX11.dylib /opt/local/lib/libpangoft2-1.0.dylib -lintl /opt/local/lib/libpng16.dylib /opt/local/lib/libtiff.dylib /opt/local/lib/libjpeg.dylib /opt/local/lib/libXrender.dylib /opt/local/lib/libXext.dylib /opt/local/lib/libXcursor.dylib /opt/local/lib/libXdamage.dylib /opt/local/lib/libXfixes.dylib /opt/local/lib/libXrandr.dylib /opt/local/lib/libXinerama.dylib -lcairo-script-interpreter
:info:build ld: unknown option: -export_dynamic
:info:build collect2: error: ld returned 1 exit status

[mascguy (Christopher Nielsen)]

-export_dynamic isn't Linux-specific. From the man page for ld:

-export_dynamic
    Preserves all global symbols in main executables during LTO. Without this option, Link Time Optimization is allowed to inline
    and remove global functions. This option is used when a main executable may load a plug-in which requires certain symbols from
    the main executable.

However, a quick Google search suggests that it's not necessarily supported with GCC.

Just as importantly, gtk4 doesn't build for macOS 10.6 and earlier. And to answer the obvious question: No, we don't have an ETA, relative to supporting 10.6.

​https://ports.macports.org/port/gtk4/details/

[barracuda156]

Replying to mascguy:

-export_dynamic isn't Linux-specific. From the man page for ld:

-export_dynamic
    Preserves all global symbols in main executables during LTO. Without this option, Link Time Optimization is allowed to inline
    and remove global functions. This option is used when a main executable may load a plug-in which requires certain symbols from
    the main executable.

However, a quick Google search suggests that it's not necessarily supported with GCC.

Just as importantly, gtk4 doesn't build for macOS 10.6 and earlier. And to answer the obvious question: No, we don't have an ETA, relative to supporting 10.6.

​https://ports.macports.org/port/gtk4/details/

Given the stage of the build it failed for me, it might succeed once the wrong flag removed or replaced with an appropriate one.

Why isn’t it building on Intel? There are no logs in details.

[barracuda156]

P.S. I don’t really get why this is invalid. This looks like a genuine bug unrelated to OS version.

[mascguy (Christopher Nielsen)]

Well, the implication that -export_dynamic is a Linux-only flag, is not correct. That's what's invalid.

Instead, it appears to a problem for GCC.

Nonetheless, we can keep this open for now, and see what our option are.

[barracuda156]

Thank you for re-opening. I think even if PowerPC systems cannot be supported here for w/e reason, fixing this for GCC on Intel is desirable, and also for 10.6 x86_64.

A quick search via BBEdit did not reveal where -export_dynamic comes from though. I will look into that again today after sorting some other stuff.

[mascguy (Christopher Nielsen)]

This appears to be natively supported by Meson, per their docs:

​https://mesonbuild.com/Reference-manual_functions.html#build_target_export_dynamic

[jmroot (Joshua Root)]

-Wl, is the mechanism provided by the compiler front-end to pass flags to the linker.

[barracuda156]

Besides, why do we even build test-suite here by default, when there is a tests variant? I suggest to add -Dbuild-testsuite=false into default config and replace it in tests.

[barracuda156]

In fact, without the testsuite (which is broken by -export_dynamic flag) gtk4 builds fine for me on 10.6 with zero manual efforts. No new patches etc.

36-25% port -v installed gtk4
The following ports are currently installed:
  gtk4 @4.10.4_0+x11 (active) requested_variants='' platform='darwin 10' archs='ppc' date='2023-08-18T15:48:12+0800'

[mascguy (Christopher Nielsen)]

Replying to barracuda156:

Besides, why do we even build test-suite here by default, when there is a tests variant? I suggest to add -Dbuild-testsuite=false into default config and replace it in tests.

Ah, that was simply an oversight on our part. (Typically there's only one test-related option. But in this case, we have to disable two.)

[Christopher Nielsen <mascguy@…>]

In 724d9ac335c8f58ac0966b9b000e1ad542b865ea/macports-ports (master):

gtk4: only build/run tests, via variant tests

Fixes: #67977

[barracuda156]

Thank you! I will see later how to get rid of that flag for tests when using GCC, but at least the port is buildable by default now, which is great.