Bug#995867: xtensor: mipsel FTBFS (relocation truncated to fit: R_MIPS_CALL16)

[Adrian Bunk]

On Sat, Oct 09, 2021 at 06:17:54PM +0200, Drew Parsons wrote:
> Source: xtensor
> Followup-For: Bug #995867
> Control: retitle -1 mipsel FTBFS (relocation truncated to fit: R_MIPS_CALL16)
> 
> The problem with undefined `__umodsi3' `__udivsi3' is not easily
> reproduced.

While -march=native is kinda OKish for test-only programs that do not 
end up in the binary package, it compiles differently depending on the
hardware.

-march=native is known to have this breakage on the oldest buildds
(eberlin, mipsel-aql-0{1,2}).

> But the mipsel build failure is consistent.
> 
> The more common symptom is "relocation truncated" errors
> e.g.
> 
> [ 39%] Linking CXX executable test_xreducer
> cd /<<PKGBUILDDIR>>/obj-mipsel-linux-gnu/test && /usr/bin/cmake -E cmake_link_script CMakeFiles/test_xreducer.dir/link.txt --verbose=1
> /usr/bin/c++ -O0 -std=c++14 -Wunused-parameter -Wextra -Wreorder -Wconversion -Wsign-conversion -Wold-style-cast -Wunused-variable -ftemplate-backtrace-limit=0 -Wl,-z,relro -rdynamic CMakeFiles/test_xreducer.dir/main.cpp.o CMakeFiles/test_xreducer.dir/test_xreducer.cpp.o -o test_xreducer  -lpthread 
> cd /<<PKGBUILDDIR>>/obj-mipsel-linux-gnu/test && /usr/bin/c++  -I/<<PKGBUILDDIR>>/include -O0 -std=c++14 -Wunused-parameter -Wextra -Wreorder -Wconversion -Wsign-conversion -Wold-style-cast -Wunused-variable -ftemplate-backtrace-limit=0 -MD -MT test/CMakeFiles/test_xexpression_traits.dir/main.cpp.o -MF CMakeFiles/test_xexpression_traits.dir/main.cpp.o.d -o CMakeFiles/test_xexpression_traits.dir/main.cpp.o -c /<<PKGBUILDDIR>>/test/main.cpp
> CMakeFiles/test_xreducer.dir/test_xreducer.cpp.o: in function `__gthread_active_p()':
> test_xreducer.cpp:(.text+0x1c): relocation truncated to fit: R_MIPS_GOT16 against `__pthread_key_create@@GLIBC_2.0'
> CMakeFiles/test_xreducer.dir/test_xreducer.cpp.o: in function `xt::xreducer_features::xreducer_features()':
> test_xreducer.cpp:(.text+0x23c): relocation truncated to fit: R_MIPS_CALL16 against `_Unwind_Resume@@GCC_3.0'
> test_xreducer.cpp:(.text+0x2ac): relocation truncated to fit: R_MIPS_CALL16 against `_Unwind_Resume@@GCC_3.0'
> CMakeFiles/test_xreducer.dir/test_xreducer.cpp.o: in function `xt::_DOCTEST_ANON_FUNC_2()':
> test_xreducer.cpp:(.text+0x418): relocation truncated to fit: R_MIPS_CALL16 against `raise@@GLIBC_2.0'
> test_xreducer.cpp:(.text+0x4b0): relocation truncated to fit: R_MIPS_CALL16 against `__cxa_begin_catch@@CXXABI_1.3'
> test_xreducer.cpp:(.text+0x4e0): relocation truncated to fit: R_MIPS_CALL16 against `__cxa_end_catch@@CXXABI_1.3'
> test_xreducer.cpp:(.text+0x504): relocation truncated to fit: R_MIPS_CALL16 against `__cxa_end_catch@@CXXABI_1.3'
> test_xreducer.cpp:(.text+0x5a4): relocation truncated to fit: R_MIPS_CALL16 against `_Unwind_Resume@@GCC_3.0'
> CMakeFiles/test_xreducer.dir/test_xreducer.cpp.o: in function `xt::_DOCTEST_ANON_FUNC_4()':
> test_xreducer.cpp:(.text+0x70c): relocation truncated to fit: R_MIPS_CALL16 against `raise@@GLIBC_2.0'
> test_xreducer.cpp:(.text+0x7a4): relocation truncated to fit: R_MIPS_CALL16 against `__cxa_begin_catch@@CXXABI_1.3'
> test_xreducer.cpp:(.text+0x7d4): additional relocation overflows omitted from the output
> collect2: error: ld returned 1 exit status
> make[3]: *** [test/CMakeFiles/test_xreducer.dir/build.make:116: test/test_xreducer] Error 1
> 
> 
> "relocation truncated" together with the virtual memory exhaustion
> seen without -O0 suggests the test program is simply too large to link.
>...

-O0 code is always larger than -Os code, and especially for C++ code 
-O0 code is also larger than -O2 code.

The patch below builds for me for mipsel on eller.

cu
Adrian

--- debian/rules.old	2021-10-26 20:34:09.552672142 +0000
+++ debian/rules	2021-10-26 20:37:13.683376341 +0000
@@ -25,7 +25,7 @@
 # try to avoid exhausting virtual memory on small-memory arches
 SMALL_MEM_ARCH_LIST := armel mipsel hurd-i386
 ifneq (,$(findstring $(space)$(DEB_HOST_ARCH)$(space), $(space)$(SMALL_MEM_ARCH_LIST)$(space)))
-  BUILD_OPTIONS += -DCMAKE_CXX_FLAGS="-O0"
+  export DEB_CXXFLAGS_MAINT_APPEND = -Os -g0
 endif
 
 # test_xnpy fails on some architectures, see Bug#985699,
@@ -36,6 +36,7 @@
   BUILD_OPTIONS += -DBUILD_TEST_XNPY=OFF
 endif
 
+BUILD_OPTIONS += -Darch_native_supported=OFF
 
 %:
 	dh $@ --with sphinxdoc