[lldb-dev] Why is function not present in target?

[Ramkumar Ramachandra via lldb-dev]

Hi,

Pavel Labath <labath at google.com> wrote:
>
> a have couple of question to better understand the situation:
> - what is the system you are trying this out on (OS, arch, ...)?
>

macOS, x86_64.


> - are you using any funny compiler options that you think we should
> know about ? (e.g. if you're using -ffunction-sections
> -Wl,--gc-sections, then the function could have been removed even if
> the parts of the compile unit stay)
>

Linker invocation:

Linking Shared Object ../../bin/maci64/libmwcgir_polly.dylib
xcrun -sdk macosx10.11 clang++ -arch x86_64 -dynamiclib -single_module
-install_name @rpath/libmwcgir_polly.dylib  -Wl,-mark_dead_strippable_dylib
  -arch x86_64 -mmacosx-version-min=10.9 -stdlib=libc++ -Wl,-dead_strip
-Wl,-dead_strip_dylibs -stdlib=libc++       -o
../../bin/maci64/libmwcgir_polly.dylib
../../derived/maci64/obj/src/cgir_polly/Analysis/MemoryAccess.o
../../derived/maci64/obj/src/cgir_polly/Analysis/SCOP.o
../../derived/maci64/obj/src/cgir_polly/Analysis/SCOPExtraction.o
../../derived/maci64/obj/src/cgir_polly/Analysis/SCOPStmt.o
../../derived/maci64/obj/src/cgir_polly/CodeGen/IRGeneration.o
../../derived/maci64/obj/src/cgir_polly/IslWrap/Isl.o
../../derived/maci64/obj/src/cgir_polly/Transform/Polly.o
../../derived/maci64/obj/src/cgir_polly/Transform/PollyImpl.o
../../derived/maci64/obj/src/cgir_polly/Util/PollyPrinter.o
../../derived/maci64/obj/src/cgir_polly/modver.o -L../../bin/maci64
-L../../bin/maci64 -lmwfoundation_usm -lmwcg_ir -lmwcgir_support
-lmwcgir_cgel -lut -lmwfl -L../../bin/maci64 -lboost_system
-L../../bin/maci64 -lmwcpp11compat
-L//mathworks/hub/3rdparty/R2017b/2334121/maci64/isl/lib -lisl
-L//mathworks/hub/3rdparty/R2017b/2309377/maci64/jsoncpp/lib -ljsoncpp
-L//mathworks/hub/3rdparty/R2017a/2105192/maci64/python2/lib -lpython2.7
-Wl,-rpath, at loader_path -Wl,-rpath, at loader_path/.
-Wl,-rpath, at loader_path/../../sys/os/maci64
xcrun -sdk macosx10.11 clang++ -arch x86_64 -c pkgtest/tMatrixAssign.cpp -o
../../derived/maci64/obj/src/cgir_polly/pkgtest/tMatrixAssign.o -MMD -MF
../../derived/maci64/obj/src/cgir_polly/pkgtest/tMatrixAssign.d -MP -MT
../../derived/maci64/obj/src/cgir_polly/pkgtest/tMatrixAssign.o
 -Iexport/include -I. -I../../src/include
-I../../derived/maci64/src/include -I../include -I../../include
-I../../derived/maci64/src/cgir_polly/include
-I../../derived/maci64/src/cgir_polly/
-isystem//mathworks/hub/3rdparty/R2017a/1971079/maci64/boost/include
-isystem//mathworks/hub/3rdparty/R2017a/1946655/maci64/cpp11compat/include
-isystem//mathworks/hub/3rdparty/R2017b/2334121/maci64/isl/include
-isystem//mathworks/hub/3rdparty/R2017b/2309377/maci64/jsoncpp/include
-isystem//mathworks/hub/3rdparty/R2017a/2105192/maci64/python2/include/python2.7
-isystem//mathworks/hub/3rdparty/R2017a/2101198/maci64/gmock/include/gmock
-isystem//mathworks/hub/3rdparty/R2017a/2101198/maci64/gmock/include/gtest
  -mmacosx-version-min=10.9
 -DMODULE_VERSION_SYMBOL=libmwcgir_polly_version
-DMODULE_DATE_SYMBOL=libmwcgir_polly_build_date -Dmw_test_main=main
-DBOOST_CB_DISABLE_DEBUG -DBOOST_THREAD_FUTURE=unique_future
-DBOOST_SPIRIT_THREADSAFE -DPHOENIX_THREADSAFE
-DBOOST_SIGNALS_NO_DEPRECATION_WARNING
-DBOOST_MPL_CFG_NO_PREPROCESSED_HEADERS -DBOOST_MPL_LIMIT_VECTOR_SIZE=30
-DBOOST_MPL_LIMIT_MAP_SIZE=30 -DNEEDS_BOOST_UNIQUE_PTR=1
 -DBUILDING_CGIR_POLLY -DGTEST_MW_USE_MW_NOT_EQUALS=1
-DGTEST_LINKED_AS_SHARED_LIBRARY=1 -DBUILDING_PKGTEST -O2 -stdlib=libc++
-pipe -D_REENTRANT -std=c++11 -g -DNDEBUG -Wextra -Wno-unused-parameter
-Wno-ignored-qualifiers -Wall -Wwrite-strings -Wpointer-arith -Wcast-qual
-Woverloaded-virtual -Wnon-virtual-dtor -Wno-unused
-Wno-inconsistent-missing-override -Wno-parentheses-equality
-Wno-self-assign -Wno-tautological-compare -std=c++11 -stdlib=libc++
-ftemplate-depth-1024 -Werror

So yes, there's  -Wl,-mark_dead_strippable_dylib + -Wl,-dead_strip +
-Wl,-dead_strip_dylibs.


> - how exactly is your function declared? (e.g. if it's declared as
> inline, or a template and unused then the compiler might not bother
> emitting it)
>

It's not inline or a template. It's just a vanilla member function.


> - could you verify (e.g. by running "objdump -t") that your function
> is indeed present in the resulting binary?
>

macOS, so:

$ nm -a libmwcgir_polly.dylib | grep toString
00000000000050b0 T __ZNK2CG8analysis4SCOP8toStringEv
0000000000026f60 T __ZNK2CG8analysis8SCOPStmt8toStringEv

Does this mean that they're present?

Ram
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