This is an archive of the discontinued LLVM Phabricator instance.

Differential D78535

libclc: Pass system libraries to the linker after llvm libraries
ClosedPublic

Authored by tstellar on Apr 20 2020, 9:52 PM.

Details

Reviewers
jvesely
Commits
rG199494f512e9: libclc: Pass system libraries to the linker after llvm libraries
rG174c41defc63: libclc: Pass system libraries to the linker after llvm libraries
Summary

The llvm libraries depend on the symbols in the system libaries, so
the system libraries need to be added after.

Diff Detail

Event Timeline

tstellar created this revision.Apr 20 2020, 9:52 PM
Herald added a project: Restricted Project. · View Herald TranscriptApr 20 2020, 9:52 PM
Herald added subscribers: llvm-commits, mgorny. · View Herald Transcript
Harbormaster completed remote builds in B54036: Diff 258898.Apr 20 2020, 10:45 PM
jvesely accepted this revision.Apr 22 2020, 4:43 PM

was this a problem with using -Wl,--as-needed?

LGTM.

This revision is now accepted and ready to land.Apr 22 2020, 4:43 PM
tstellar added a comment.Apr 23 2020, 7:23 AM
In D78535#1998136, @jvesely wrote:

was this a problem with using -Wl,--as-needed?

LGTM.

No, I was hitting this when using the default build options for both LLVM and libclc.

jvesely added a comment.Apr 23 2020, 5:16 PM
In D78535#1999173, @tstellar wrote:
In D78535#1998136, @jvesely wrote:

was this a problem with using -Wl,--as-needed?

LGTM.

No, I was hitting this when using the default build options for both LLVM and libclc.

that's weird. linker shouldn't really drop libraries unless as-needed is used. can you post the falling cmdline?

tstellar added a comment.Apr 29 2020, 11:44 AM
In D78535#2000814, @jvesely wrote:
In D78535#1999173, @tstellar wrote:
In D78535#1998136, @jvesely wrote:

was this a problem with using -Wl,--as-needed?

LGTM.

No, I was hitting this when using the default build options for both LLVM and libclc.

that's weird. linker shouldn't really drop libraries unless as-needed is used. can you post the falling cmdline?

This is the failing cmdline (from here https://github.com/tstellar/llvm-project/runs/587088911):

/usr/bin/c++ CMakeFiles/prepare_builtins.dir/utils/prepare-builtins.cpp.o -o prepare_builtins -L/home/runner/work/llvm-project/llvm-project/build/lib -Wl,-rpath,/home/runner/work/llvm-project/llvm-project/build/lib -lz -lrt -ldl -ltinfo -lpthread -lm -lxml2 -lLLVMBitWriter -lLLVMAnalysis -lLLVMProfileData -lLLVMObject -lLLVMTextAPI -lLLVMMCParser -lLLVMMC -lLLVMDebugInfoCodeView -lLLVMDebugInfoMSF -lLLVMBitReader -lLLVMCore -lLLVMRemarks -lLLVMBitstreamReader -lLLVMBinaryFormat -lLLVMSupport -lLLVMDemangle

jvesely added a comment.Apr 29 2020, 2:42 PM
In D78535#2010720, @tstellar wrote:

This is the failing cmdline (from here https://github.com/tstellar/llvm-project/runs/587088911):

/usr/bin/c++ CMakeFiles/prepare_builtins.dir/utils/prepare-builtins.cpp.o -o prepare_builtins -L/home/runner/work/llvm-project/llvm-project/build/lib -Wl,-rpath,/home/runner/work/llvm-project/llvm-project/build/lib -lz -lrt -ldl -ltinfo -lpthread -lm -lxml2 -lLLVMBitWriter -lLLVMAnalysis -lLLVMProfileData -lLLVMObject -lLLVMTextAPI -lLLVMMCParser -lLLVMMC -lLLVMDebugInfoCodeView -lLLVMDebugInfoMSF -lLLVMBitReader -lLLVMCore -lLLVMRemarks -lLLVMBitstreamReader -lLLVMBinaryFormat -lLLVMSupport -lLLVMDemangle

Looks like this is caused by Ubuntu enabling -Wl,--as-needed by default (since 11.10) [0]

[0] https://wiki.ubuntu.com/ToolChain/CompilerFlags#A-Wl.2C--as-needed

Closed by commit rG174c41defc63: libclc: Pass system libraries to the linker after llvm libraries (authored by tstellar). · Explain WhyApr 29 2020, 3:41 PM
This revision was automatically updated to reflect the committed changes.

Revision Contents

PathSize
libclc/
2 lines

Diff 261067

libclc/CMakeLists.txt

Show First 20 Lines • Show All 119 Lines • ▼ Show 20 Lines
# This needs to be set before any target that needs it # This needs to be set before any target that needs it
link_directories( ${LLVM_LIBDIR} ) link_directories( ${LLVM_LIBDIR} )
# Setup prepare_builtins tools # Setup prepare_builtins tools
add_executable( prepare_builtins utils/prepare-builtins.cpp ) add_executable( prepare_builtins utils/prepare-builtins.cpp )
target_compile_options( prepare_builtins PRIVATE ${LLVM_CXX_FLAGS} ) target_compile_options( prepare_builtins PRIVATE ${LLVM_CXX_FLAGS} )
target_compile_definitions( prepare_builtins PRIVATE ${LLVM_VERSION_DEFINE} ) target_compile_definitions( prepare_builtins PRIVATE ${LLVM_VERSION_DEFINE} )
target_link_libraries( prepare_builtins PRIVATE ${LLVM_SYSTEM_LIBS} )
target_link_libraries( prepare_builtins PRIVATE ${LLVM_LIBS} ) target_link_libraries( prepare_builtins PRIVATE ${LLVM_LIBS} )
target_link_libraries( prepare_builtins PRIVATE ${LLVM_SYSTEM_LIBS} )
# Setup arch devices # Setup arch devices
set( r600--_devices cedar cypress barts cayman ) set( r600--_devices cedar cypress barts cayman )
set( amdgcn--_devices tahiti ) set( amdgcn--_devices tahiti )
set( amdgcn-mesa-mesa3d_devices ${amdgcn--_devices} ) set( amdgcn-mesa-mesa3d_devices ${amdgcn--_devices} )
set( amdgcn--amdhsa_devices none ) set( amdgcn--amdhsa_devices none )
set( nvptx--_devices none ) set( nvptx--_devices none )
set( nvptx64--_devices none ) set( nvptx64--_devices none )
▲ Show 20 Lines • Show All 174 Lines • Show Last 20 Lines