Re: [PATCH] Ensure that MIPS target code is compiled for the O32 ABI.

[Mark H Weaver]

Andrei Borzenkov <address@hidden> writes:

> 13.09.2015 05:41, Mark H Weaver пишет:
>> I'm glad to report that with your new patch, GRUB successfully builds on
>> GuixSD mips64el with TARGET_CC=clang.  I haven't yet tried booting it
>> though.
>>
>
> Did you have chance to test whether compiled grub actually work?

Not yet.  I'll try to do it in the next few days.

>> The warning above makes me doubt the portability and future-proofness of
>> the link step of this test.  This problem could be avoided entirely by
>> omitting the link step.  The link step serves no purpose in this test,
>> and is a potential source of portability problems.
>>
>
> This step helped us to catch endianness mismatch; we want to ensure in
> this case that full toolchain works to produce final binary.

Okay, fair enough :)

> Please test two attached patches. They separate o32 test from
> endianness test. I compile-tested them using cross-binutils for mips
> and powerpc64le to compile for mipsel and powerpc. The first patch
> also adds additional _start and __start symbols to endianness tests to
> avoid compiler warnings.

The little-endian-option test fails with GCC 5.2.0.  The relevant errors
from config.log are:

  gcc: error: unrecognized command line option '-target'
  gcc: error: unrecognized command line option '-mlittle-endian'

I guess the error messages above should be enough.  Let me know if you
want more.

It succeeds with clang 3.6.0.  See below for the relevant excerpts of
config.log.

     Thanks,
       Mark


--8<---------------cut here---------------start------------->8---
configure:24669: checking for options to get little-endian compilation
configure:24704: 
/gnu/store/yjmchvkz0kmz4s1sxc0p89imfik68qzg-clang-3.6.0/bin/clang -o conftest  
-Os -Wall -W -Wshadow -Wpointer-arith -Wundef -Wchar-subscripts -Wcomment 
-Wdeprecated-declarations -Wdisabled-optimization -Wdiv-by-zero -Wfloat-equal 
-Wformat-extra-args -Wformat-security -Wformat-y2k -Wimplicit 
-Wimplicit-function-declaration -Wimplicit-int -Wmain -Wmissing-braces 
-Wmissing-format-attribute -Wmultichar -Wparentheses -Wreturn-type 
-Wsequence-point -Wshadow -Wsign-compare -Wswitch -Wtrigraphs -Wunknown-pragmas 
-Wunused -Wunused-function -Wunused-label -Wunused-parameter -Wunused-value  
-Wunused-variable -Wwrite-strings -Wnested-externs -Wstrict-prototypes -g 
-Wredundant-decls -Wmissing-prototypes -Wmissing-declarations -Wcast-align  
-Wextra -Wattributes -Wendif-labels -Winit-self -Wint-to-pointer-cast 
-Winvalid-pch -Wmissing-field-initializers -Wnonnull -Woverflow -Wvla 
-Wpointer-to-int-cast -Wstrict-aliasing -Wvariadic-macros 
-Wvolatile-register-var -Wpointer-sign -Wmissing-include-dirs 
-Wmissing-prototypes -Wmissing-declarations -Wformat=2 -target mipsel -Wl,-EL 
-Werror  -Wall -W  -DGRUB_CPU_MIPSEL=1 -DGRUB_MACHINE_MIPS_LOONGSON=1 
-DGRUB_MACHINE=MIPS_LOONGSON  -nostdlib -static conftest.c  >&5
ld: /tmp/conftest-78445a.o: ABI is incompatible with that of the selected 
emulation
ld: failed to merge target specific data of file /tmp/conftest-78445a.o
collect2: error: ld returned 1 exit status
clang-3.6: error: linker (via gcc) command failed with exit code 1 (use -v to 
see invocation)
configure:24704: $? = 1
configure: failed program was:
[...]
configure:24704: 
/gnu/store/yjmchvkz0kmz4s1sxc0p89imfik68qzg-clang-3.6.0/bin/clang -o conftest  
-Os -Wall -W -Wshadow -Wpointer-arith -Wundef -Wchar-subscripts -Wcomment 
-Wdeprecated-declarations -Wdisabled-optimization -Wdiv-by-zero -Wfloat-equal 
-Wformat-extra-args -Wformat-security -Wformat-y2k -Wimplicit 
-Wimplicit-function-declaration -Wimplicit-int -Wmain -Wmissing-braces 
-Wmissing-format-attribute -Wmultichar -Wparentheses -Wreturn-type 
-Wsequence-point -Wshadow -Wsign-compare -Wswitch -Wtrigraphs -Wunknown-pragmas 
-Wunused -Wunused-function -Wunused-label -Wunused-parameter -Wunused-value  
-Wunused-variable -Wwrite-strings -Wnested-externs -Wstrict-prototypes -g 
-Wredundant-decls -Wmissing-prototypes -Wmissing-declarations -Wcast-align  
-Wextra -Wattributes -Wendif-labels -Winit-self -Wint-to-pointer-cast 
-Winvalid-pch -Wmissing-field-initializers -Wnonnull -Woverflow -Wvla 
-Wpointer-to-int-cast -Wstrict-aliasing -Wvariadic-macros 
-Wvolatile-register-var -Wpointer-sign -Wmissing-include-dirs 
-Wmissing-prototypes -Wmissing-declarations -Wformat=2 -target mipsel -Werror  
-Wall -W  -DGRUB_CPU_MIPSEL=1 -DGRUB_MACHINE_MIPS_LOONGSON=1 
-DGRUB_MACHINE=MIPS_LOONGSON  -nostdlib -static conftest.c  >&5
ld: /tmp/conftest-66051b.o: ABI is incompatible with that of the selected 
emulation
ld: failed to merge target specific data of file /tmp/conftest-66051b.o
collect2: error: ld returned 1 exit status
clang-3.6: error: linker (via gcc) command failed with exit code 1 (use -v to 
see invocation)
configure:24704: $? = 1
configure: failed program was:
[...]
configure:24704: 
/gnu/store/yjmchvkz0kmz4s1sxc0p89imfik68qzg-clang-3.6.0/bin/clang -o conftest  
-Os -Wall -W -Wshadow -Wpointer-arith -Wundef -Wchar-subscripts -Wcomment 
-Wdeprecated-declarations -Wdisabled-optimization -Wdiv-by-zero -Wfloat-equal 
-Wformat-extra-args -Wformat-security -Wformat-y2k -Wimplicit 
-Wimplicit-function-declaration -Wimplicit-int -Wmain -Wmissing-braces 
-Wmissing-format-attribute -Wmultichar -Wparentheses -Wreturn-type 
-Wsequence-point -Wshadow -Wsign-compare -Wswitch -Wtrigraphs -Wunknown-pragmas 
-Wunused -Wunused-function -Wunused-label -Wunused-parameter -Wunused-value  
-Wunused-variable -Wwrite-strings -Wnested-externs -Wstrict-prototypes -g 
-Wredundant-decls -Wmissing-prototypes -Wmissing-declarations -Wcast-align  
-Wextra -Wattributes -Wendif-labels -Winit-self -Wint-to-pointer-cast 
-Winvalid-pch -Wmissing-field-initializers -Wnonnull -Woverflow -Wvla 
-Wpointer-to-int-cast -Wstrict-aliasing -Wvariadic-macros 
-Wvolatile-register-var -Wpointer-sign -Wmissing-include-dirs 
-Wmissing-prototypes -Wmissing-declarations -Wformat=2 -target mipsel-linux-gnu 
-Wl,-EL -Werror  -Wall -W  -DGRUB_CPU_MIPSEL=1 -DGRUB_MACHINE_MIPS_LOONGSON=1 
-DGRUB_MACHINE=MIPS_LOONGSON  -nostdlib -static conftest.c  >&5
configure:24704: $? = 0
configure:24712: result: -target mipsel-linux-gnu -Wl,-EL
configure:24728: checking for options to force MIPS o32 ABI
configure:24761: 
/gnu/store/yjmchvkz0kmz4s1sxc0p89imfik68qzg-clang-3.6.0/bin/clang -o conftest  
-Os -Wall -W -Wshadow -Wpointer-arith -Wundef -Wchar-subscripts -Wcomment 
-Wdeprecated-declarations -Wdisabled-optimization -Wdiv-by-zero -Wfloat-equal 
-Wformat-extra-args -Wformat-security -Wformat-y2k -Wimplicit 
-Wimplicit-function-declaration -Wimplicit-int -Wmain -Wmissing-braces 
-Wmissing-format-attribute -Wmultichar -Wparentheses -Wreturn-type 
-Wsequence-point -Wshadow -Wsign-compare -Wswitch -Wtrigraphs -Wunknown-pragmas 
-Wunused -Wunused-function -Wunused-label -Wunused-parameter -Wunused-value  
-Wunused-variable -Wwrite-strings -Wnested-externs -Wstrict-prototypes -g 
-Wredundant-decls -Wmissing-prototypes -Wmissing-declarations -Wcast-align  
-Wextra -Wattributes -Wendif-labels -Winit-self -Wint-to-pointer-cast 
-Winvalid-pch -Wmissing-field-initializers -Wnonnull -Woverflow -Wvla 
-Wpointer-to-int-cast -Wstrict-aliasing -Wvariadic-macros 
-Wvolatile-register-var -Wpointer-sign -Wmissing-include-dirs 
-Wmissing-prototypes -Wmissing-declarations -Wformat=2 -target mipsel-linux-gnu 
  -Werror  -Wall -W  -DGRUB_CPU_MIPSEL=1 -DGRUB_MACHINE_MIPS_LOONGSON=1 
-DGRUB_MACHINE=MIPS_LOONGSON  -nostdlib -static conftest.c  >&5
configure:24761: $? = 0
configure:24769: result: 
--8<---------------cut here---------------end--------------->8---