[LLVM 4.0] Symbol lookup error when linking dylibs

[mattico]

cc #37609

These two tests fail when testing the compiler with a current LLVM build from the release_40 branch.

run-make/llvm-pass
run-make/rustc-macro-dep-files

The two failures are similar enough that they're probably related.

test [run-make] run-make/llvm-pass ... FAILED

stdout:
------------------------------------------
c++ -ffunction-sections -fdata-sections -fPIC -m64  -I/home/matt/Code/llvm/include -I/home/matt/Code/llvm/build-40/include  -fPIC -fvisibility-inlines-hidden -Wall -W -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-long-long -Wno-maybe-uninitialized -Wdelete-non-virtual-dtor -Wno-comment -Werror=date-time -std=c++11 -g  -fno-exceptions -fno-rtti -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -c llvm-function-pass.so.cc -o /home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/test/run-make/llvm-pass.stage1-x86_64-unknown-linux-gnu/libllvm-function-pass.o
ar crus /home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/test/run-make/llvm-pass.stage1-x86_64-unknown-linux-gnu/libllvm-function-pass.a /home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/test/run-make/llvm-pass.stage1-x86_64-unknown-linux-gnu/libllvm-function-pass.o
c++ -ffunction-sections -fdata-sections -fPIC -m64  -I/home/matt/Code/llvm/include -I/home/matt/Code/llvm/build-40/include  -fPIC -fvisibility-inlines-hidden -Wall -W -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-long-long -Wno-maybe-uninitialized -Wdelete-non-virtual-dtor -Wno-comment -Werror=date-time -std=c++11 -g  -fno-exceptions -fno-rtti -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -c llvm-module-pass.so.cc -o /home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/test/run-make/llvm-pass.stage1-x86_64-unknown-linux-gnu/libllvm-module-pass.o
ar crus /home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/test/run-make/llvm-pass.stage1-x86_64-unknown-linux-gnu/libllvm-module-pass.a /home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/test/run-make/llvm-pass.stage1-x86_64-unknown-linux-gnu/libllvm-module-pass.o
LD_LIBRARY_PATH="/home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/test/run-make/llvm-pass.stage1-x86_64-unknown-linux-gnu:/home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/stage1/lib:/home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/stage1-tools/x86_64-unknown-linux-gnu/release/deps:/home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/stage1/lib/rustlib/x86_64-unknown-linux-gnu/lib:" '/home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/stage1/bin/rustc' --out-dir /home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/test/run-make/llvm-pass.stage1-x86_64-unknown-linux-gnu -L /home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/test/run-make/llvm-pass.stage1-x86_64-unknown-linux-gnu  plugin.rs -C prefer-dynamic
LD_LIBRARY_PATH="/home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/test/run-make/llvm-pass.stage1-x86_64-unknown-linux-gnu:/home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/stage1/lib:/home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/stage1-tools/x86_64-unknown-linux-gnu/release/deps:/home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/stage1/lib/rustlib/x86_64-unknown-linux-gnu/lib:" '/home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/stage1/bin/rustc' --out-dir /home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/test/run-make/llvm-pass.stage1-x86_64-unknown-linux-gnu -L /home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/test/run-make/llvm-pass.stage1-x86_64-unknown-linux-gnu  main.rs
Makefile:9: recipe for target 'all' failed

------------------------------------------
stderr:
------------------------------------------
ar: `u' modifier ignored since `D' is the default (see `U')
ar: `u' modifier ignored since `D' is the default (see `U')
/home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/stage1/bin/rustc: symbol lookup error: /home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/test/run-make/llvm-pass.stage1-x86_64-unknown-linux-gnu/libsome_plugin.so: undefined symbol: _ZN12rustc_plugin8registry8Registry18register_llvm_pass17h3ddb9f4cf0e74ab9E
make: *** [all] Error 127

test [run-make] run-make/rustc-macro-dep-files ... FAILED

stdout:
------------------------------------------
LD_LIBRARY_PATH="/home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/test/run-make/rustc-macro-dep-files.stage1-x86_64-unknown-linux-gnu:/home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/stage1/lib:/home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/stage1-tools/x86_64-unknown-linux-gnu/release/deps:/home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/stage1/lib/rustlib/x86_64-unknown-linux-gnu/lib:" '/home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/stage1/bin/rustc' --out-dir /home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/test/run-make/rustc-macro-dep-files.stage1-x86_64-unknown-linux-gnu -L /home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/test/run-make/rustc-macro-dep-files.stage1-x86_64-unknown-linux-gnu  foo.rs
LD_LIBRARY_PATH="/home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/test/run-make/rustc-macro-dep-files.stage1-x86_64-unknown-linux-gnu:/home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/stage1/lib:/home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/stage1-tools/x86_64-unknown-linux-gnu/release/deps:/home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/stage1/lib/rustlib/x86_64-unknown-linux-gnu/lib:" '/home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/stage1/bin/rustc' --out-dir /home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/test/run-make/rustc-macro-dep-files.stage1-x86_64-unknown-linux-gnu -L /home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/test/run-make/rustc-macro-dep-files.stage1-x86_64-unknown-linux-gnu  bar.rs --emit dep-info
Makefile:4: recipe for target 'all' failed

------------------------------------------
stderr:
------------------------------------------
error: /home/matt/Code/Rust/rust/build/x86_64-unknown-linux-gnu/test/run-make/rustc-macro-dep-files.stage1-x86_64-unknown-linux-gnu/libfoo.so: undefined symbol: _ZN40_$LT$alloc..raw_vec..RawVec$LT$T$GT$$GT$6double14_MSG_FILE_LINE17h026b1bdceb71d8dcE
  --> bar.rs:12:1
   |
12 | extern crate foo;
   | ^^^^^^^^^^^^^^^^^

make: *** [all] Error 101

[mattico]

Oh and these tests only fail with a stage 1 compiler... stage 2 works fine.

[japaric]

Oh and these tests only fail with a stage 1 compiler... stage 2 works fine.

Do these tests pass with a stage1 compiler that doesn't include the LLVM change? IME, stage1 test suite almost never suceeds.

[mattico]

Hm. The contributing guide suggests that running tests on stage 1 is okay. I suppose that all tests should always pass but the ones which aren't run on every PR tend to bitrot. Definitely need to try this with another LLVM version, still waiting for the compile to finish...

[mattico]

Can now confirm these tests do pass using in-tree LLVM.

[mattico]

I'm going to close this, since the issue is certainly resolved now that we're on LLVM 4 and the tests are passing.