Fine granularity of control over libgcc* search paths

[R jd <3246251196ryan@gmail.com>]

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I have tried for some hours to figure out how to get full control over the
paths that are implicitly searched for *libgcc.a*.

As an example, here is the command that is passed to *collect2*:

/usr/lib/gcc/x86_64-linux-gnu/11/collect2 -plugin
/usr/lib/gcc/x86_64-linux-gnu/11/liblto_plugin.so
-plugin-opt=/usr/lib/gcc/x86_64-linux-gnu/11/lto-wrapper
-plugin-opt=-fresolution=/tmp/ccwIgXt9.res -plugin-opt=-pass-through=-lgcc
-plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lc
-plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lgcc_s
--build-id --eh-frame-hdr -m elf_x86_64 --hash-style=gnu --as-needed
-dynamic-linker /lib64/ld-linux-x86-64.so.2 -pie -z now -z relro -o main
/usr/lib/gcc/x86_64-linux-gnu/11/../../../x86_64-linux-gnu/Scrt1.o
/usr/lib/gcc/x86_64-linux-gnu/11/../../../x86_64-linux-gnu/crti.o
/usr/lib/gcc/x86_64-linux-gnu/11/crtbeginS.o
-L/usr/lib/gcc/x86_64-linux-gnu/11
-L/usr/lib/gcc/x86_64-linux-gnu/11/../../../x86_64-linux-gnu
-L/usr/lib/gcc/x86_64-linux-gnu/11/../../../../lib -L/lib/x86_64-linux-gnu
-L/lib/../lib -L/usr/lib/x86_64-linux-gnu -L/usr/lib/../lib
-L/usr/lib/gcc/x86_64-linux-gnu/11/../../.. --verbose /tmp/ccR9vB4k.o -lgcc
--push-state --as-needed -lgcc_s --pop-state -lc -lgcc --push-state
--as-needed -lgcc_s --pop-state /usr/lib/gcc/x86_64-linux-gnu/11/crtendS.o
/usr/lib/gcc/x86_64-linux-gnu/11/../../../x86_64-linux-gnu/crtn.o

This boils down to something like:

[LINK_SPEC] [STARTFILE_SPEC] [The Evasive Library Paths] --verbose
/tmp/ccR9vB4k.o [REAL_LIBGCC_SPEC] [LIB_SPEC] .....

Where, [The Evasive Library Paths] = -L/usr/lib/gcc/x86_64-linux-gnu/11
-L/usr/lib/gcc/x86_64-linux-gnu/11/../../../x86_64-linux-gnu
-L/usr/lib/gcc/x86_64-linux-gnu/11/../../../../lib -L/lib/x86_64-linux-gnu
-L/lib/../lib -L/usr/lib/x86_64-linux-gnu -L/usr/lib/../lib
-L/usr/lib/gcc/x86_64-linux-gnu/11/../../..

It is [The Evasive Library Paths] that I am trying to get fine control
over. It seems that these are just automatically inserted because we are
linking with -lgcc which makes total sense - but I need to have full
control over it and may want to change it. The rest of the command line for
*collect2* is understandable and modifiable since I can match it up with
the relevant SPEC file. Only these evasive library paths are causing me a
lot of wasted hours.

I was looking at *LINK_COMMAND_SPEC* (
https://gcc.gnu.org/onlinedocs/gcc-5.2.0/gccint/Driver.html) as a potential
work around, but I thought that, since it is already late, I would just ask
on here.

Regards,