Our parsing of linker flags can be easily confused by, e.g.,
-Wl,-undefined -Wl,dynamic_lookup,-dead_strip_dylibs
The current code that tries to detect these flags will erroneously
conclude that they were not passed.
This change fixes that.
A local `ruby` build failed while building extensions, with:
*** Following extensions are not compiled:
-test-/file:
Could not be configured. It will not be installed.
/tmp/ruby-20240824-893184-ehcnsa/ruby-3.3.4/lib/mkmf.rb:480: The compiler failed to generate an executable file.
You have to install development tools first.
Check ext/-test-/file/mkmf.log for more details.
-test-/symbol:
Could not be configured. It will not be installed.
/tmp/ruby-20240824-893184-ehcnsa/ruby-3.3.4/lib/mkmf.rb:480: The compiler failed to generate an executable file.
You have to install development tools first.
Check ext/-test-/symbol/mkmf.log for more details.
[...]
`mkmf.log` indicated that the compiler shim failed to load `pathname`:
LD_LIBRARY_PATH=.:../../.. "gcc-13 -o conftest -I../../../.ext/include/aarch64-linux -I../../.././include -I../../.././ext/-test-/file -I/home/linuxbrew/.linuxbrew/opt/libyaml/include -I/home/linuxbrew/.linuxbrew/opt/openssl@3/include -O3 -fno-fast-math -ggdb3 -Wall -Wextra -Wdeprecated-declarations -Wdiv-by-zero -Wduplicated-cond -Wimplicit-function-declaration -Wimplicit-int -Wpointer-arith -Wwrite-strings -Wold-style-definition -Wimplicit-fallthrough=0 -Wmissing-noreturn -Wno-cast-function-type -Wno-constant-logical-operand -Wno-long-long -Wno-missing-field-initializers -Wno-overlength-strings -Wno-packed-bitfield-compat -Wno-parentheses-equality -Wno-self-assign -Wno-tautological-compare -Wno-unused-parameter -Wno-unused-value -Wsuggest-attribute=format -Wsuggest-attribute=noreturn -Wunused-variable -Wmisleading-indentation -Wundef -fPIC conftest.c -L. -L../../.. -L/home/linuxbrew/.linuxbrew/opt/libyaml/lib -Wl,-rpath,/home/linuxbrew/.linuxbrew/opt/libyaml/lib -L/home/linuxbrew/.linuxbrew/opt/openssl@3/lib -Wl,-rpath,/home/linuxbrew/.linuxbrew/opt/openssl@3/lib -L. -fstack-protector-strong -L/home/linuxbrew/.linuxbrew/opt/libyaml/lib -Wl,-rpath,/home/linuxbrew/.linuxbrew/opt/libyaml/lib -L/home/linuxbrew/.linuxbrew/opt/openssl@3/lib -Wl,-rpath,/home/linuxbrew/.linuxbrew/opt/openssl@3/lib -rdynamic -Wl,-export-dynamic -Wl,--no-as-needed -Wl,-rpath,/home/linuxbrew/.linuxbrew/Cellar/ruby/3.3.4/lib -L/home/linuxbrew/.linuxbrew/Cellar/ruby/3.3.4/lib -lruby-static -lz -lrt -lrt -ldl -lcrypt -lm -lpthread -lm -lpthread -lc"
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/shims/linux/super/gcc-13:12:in `require': cannot load such file -- pathname (LoadError)
from /home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/shims/linux/super/gcc-13:12:in `<main>'
I believe this was due to `../../..` in `LD_LIBRARY_PATH` containing
`libruby.so`, causing the Ruby script to load the being-built Ruby
library instead of the system/portable one.
We have a handful of formulae that use Homebrew `make` to build. Doing
this evades our compiler shims. Let's try to avoid this by allowing our
shims to support usage of Homebrew `make` by calling it as `gmake` in
the formula.
The `opencv@3` build calls `gmake`, which ends up evading our compiler
shim and results in a build failure because of a `-Werror` flag.
ClosesHomebrew/homebrew-core#132966.
- check the version of `/usr/bin/ld` for support of `-no_fixup_chains`
- check for usage of the `-fuse-ld` flag, since this flag is only
supported by Apple ld64
Also, call `no_fixup_chains` when setting up the build environment.
Invoking `ld` with `-undefined dynamic_lookup` emits a warning starting
Xcode 14:
ld: warning: -undefined dynamic_lookup may not work with chained fixups
Chained fixups is a linker optimisation that results in faster binary
load times, and is enabled by default starting Xcode 13 when the target
is macOS 12 or newer.
However, this interacts poorly with `-undefined dynamic_lookup`, and
Xcode will disable chained fixups when it is invoked with this flag
starting Xcode 14.3. Until then, we may be shipping binaries that are
broken in subtle ways, so let's disable chained fixups when necessary
instead.
I patterned the changes here after the handling of `-no_weak_imports`.
The only difference is that we need to check the flags that were passed
to the linker first to see if we do need to disable chained fixups.
For additional context, see:
https://developer.apple.com/documentation/xcode-release-notes/xcode-13-release-noteshttps://www.wwdcnotes.com/notes/wwdc22/110362/https://www.emergetools.com/blog/posts/iOS15LaunchTimehttps://github.com/python/cpython/issues/97524https://github.com/pybind/pybind11/pull/4301
A fix for the script was made in 95b0bd160fdbf00adb457a54d28b9925d2663494 but the user may be updating from an older version of brew, which won't have this fix.
