Consistently use RUNPATH in our libraries
#46464
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When loading dependencies on Linux, we can either use `RPATH` or `RUNPATH` as a list of relative paths to search for libraries. The difference, for our purposes, mainly lies within how this interacts with `LD_LIBRARY_PATH`: `RPATH` is searched first, then `LD_LIBRARY_PATH`, then `RUNPATH`. So by using `RUNPATH` here, we are explicitly allowing ourselves to be overridden by `LD_LIBRARY_PATH`. This is fine, as long as we are consistent across our entire library line, however in the `v1.8.0` release, there was an inconsistency, reported in [0]. The inconsistency occured because of the following confluence of factors: - Ancient `ld` builds (such as the one used in our build environment) do not default to using `RUNPATH`, but instead use `RPATH`. - `patchelf`, when it rewrites the RPATH, will default to using `RUNPATH` instead. - We were only using `patchelf` on `libjulia-internal`, not on `libjulia-codegen`, which was newly added in `v1.8`. These three factors together caused us to ship a binary with `RUNPATH` in `libjulia-internal`, but `RPATH` in `libjulia-codegen`, which caused loading to fail in [0] due to first `libjulia-internal` being loaded, (which brought in the external `libstdc++`), then `libjulia-codegen` failed to load (because it found an incompatible `libstdc++`), causing the mysterious compiler error. This PR fixes this twofold; first, when building the libraries in the first place, we pass `--enable-new-dtags` to the linker to encourage it to use `runpath` when possible. This removes the possibility for a missing `patchelf` invocation to break things in this way. Second, we apply `patchelf` properly to `libjulia-codegen` as well. [0] #46409
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Co-authored-by: Mosè Giordano <giordano@users.noreply.github.com>
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When loading dependencies on Linux, we can either use
RPATHorRUNPATHas a list of relative paths to search for libraries. Thedifference, for our purposes, mainly lies within how this interacts with
LD_LIBRARY_PATH:RPATHis searched first, thenLD_LIBRARY_PATH,then
RUNPATH. So by usingRUNPATHhere, we are explicitly allowingourselves to be overridden by
LD_LIBRARY_PATH. This is fine, as longas we are consistent across our entire library line, however in the
v1.8.0release, there was an inconsistency, reported in [0].The inconsistency occured because of the following confluence of factors:
ldbuilds (such as the one used in our build environment)do not default to using
RUNPATH, but instead useRPATH.patchelf, when it rewrites the RPATH, will default to usingRUNPATHinstead.patchelfonlibjulia-internal, not onlibjulia-codegen, which was newly added inv1.8.These three factors together caused us to ship a binary with
RUNPATHin
libjulia-internal, butRPATHinlibjulia-codegen, which causedloading to fail in [0] due to first
libjulia-internalbeing loaded,(which brought in the external
libstdc++), thenlibjulia-codegenfailed to load (because it found an incompatible
libstdc++), causingthe mysterious compiler error.
This PR fixes this twofold; first, when building the libraries in the
first place, we pass
--enable-new-dtagsto the linker to encourage itto use
runpathwhen possible. This removes the possibility for amissing
patchelfinvocation to break things in this way. Second, weapply
patchelfproperly tolibjulia-codegenas well.[0] #46409