gnatlink vs. -mthumb -march=armv7-a+simd -mfloat-abi=hard

Tue Jun 25 12:53:06 GMT 2024

On 24.06.24 16:06, Sebastian Huber wrote:
> On 28.04.22 10:16, Sebastian Huber wrote:
>> Hello,
>>
>> I test currently the Ada support for RTEMS in GCC 12. We have a 
>> -mthumb -march=armv7-a+simd -mfloat-abi=hard multilib for which the 
>> Ada RTS is built like this:
>>
>> make[4]: Entering directory 
>> '/tmp/sh/b-gcc-arm-rtems6/arm-rtems6/thumb/armv7-a+simd/hard/libada'
>> make -C ../../../../.././gcc/ada "MAKEOVERRIDES=" "LDFLAGS=-mthumb 
>> -march=armv7-a+simd -mfloat-abi=hard" "LN_S=ln -s" "SHELL=/bin/sh" 
>> "GNATLIBFLAGS=-W -Wall -gnatpg -nostdinc -mthumb -march=armv7-a+simd 
>> -mfloat-abi=hard" "GNATLIBCFLAGS=-g -O2 -mthumb -march=armv7-a+simd 
>> -mfloat-abi=hard" "GNATLIBCFLAGS_FOR_C=-W -Wall -g -O2 -g -O2 
>> -fexceptions -DIN_RTS -DHAVE_GETIPINFO  -mthumb -march=armv7-a+simd 
>> -mfloat-abi=hard" "PICFLAG_FOR_TARGET=-fPIC" "THREAD_KIND=native" 
>> "TRACE=no" "MULTISUBDIR=/thumb/armv7-a+simd/hard" 
>> "libsubdir=/tmp/sh/i-arm-rtems6/lib64/gcc/arm-rtems6/12.0.1/thumb/armv7-a+simd/hard" "toolexeclibdir=/tmp/sh/i-arm-rtems6/lib64/gcc/arm-rtems6/12.0.1/thumb/armv7-a+simd/hard/adalib" "objext=.o" "prefix=/tmp/sh/i-arm-rtems6" "exeext=.exeext.should.not.be.used " 'CC=the.host.compiler.should.not.be.needed' "GCC_FOR_TARGET=/tmp/sh/b-gcc-arm-rtems6/./gcc/xgcc -B/tmp/sh/b-gcc-arm-rtems6/./gcc/ -nostdinc -B/tmp/sh/b-gcc-arm-rtems6/arm-rtems6/newlib/ -isystem /tmp/sh/b-gcc-arm-rtems6/arm-rtems6/newlib/targ-include -isystem /home/EB/sebastian_h/src/gcc/newlib/libc/include -B/tmp/sh/i-arm-rtems6/arm-rtems6/bin/ -B/tmp/sh/i-arm-rtems6/arm-rtems6/lib/ -isystem /tmp/sh/i-arm-rtems6/arm-rtems6/include -isystem /tmp/sh/i-arm-rtems6/arm-rtems6/sys-include   " "CFLAGS=-g -O2  -mthumb -march=armv7-a+simd -mfloat-abi=hard" ./bldtools/oscons/xoscons
>>
>> When I try to link a test application I get this error:
>>
>> arm-rtems7-gnatlink 
>> /tmp/sh/b-rtems/arm/realview_pbx_a9_qemu/testsuites/ada/samples/nsecs/nsecs.ali testsuites/ada/samples/nsecs/init.o -qnolinkcmds -T linkcmds.realview_pbx_a9_qemu -Wl,--wrap=printf -Wl,--wrap=puts -Wl,--wrap=putchar -L. -lrtemscpu -lrtemsbsp -lrtemstest -qrtems -mthumb -march=armv7-a+simd -mfloat-abi=hard -mtune=cortex-a9 -Wl,--gc-sections -L/home/EB/sebastian_h/src/rtems/bsps/arm/shared/start -L/home/EB/sebastian_h/src/rtems/bsps/arm/realview-pbx-a9/start -o /tmp/sh/b-rtems/arm/realview_pbx_a9_qemu/testsuites/ada/ada_nsecs.exe
>> /opt/rtems/7/lib/gcc/arm-rtems7/12.0.1/thumb/armv7-a+simd/hard/adainclude/s-secsta.ads:288:9: sorry, unimplemented: Thumb-1 'hard-float' VFP ABI
>>
>> The s-secsta.ads seems to be from the right multilib directory 
>> (Thumb-2), however, I get a sorry message related to Thumb-1?
> 
> I tried it again with GCC 13, but the problem still exists. I tried to 
> use strace to get some more insights (the environment variables are 
> partially shown):
> 
> [pid 110912] execve("/opt/rtems-6-zynq-1/bin/arm-rtems6-gnatmake", 
> ["/opt/rtems-6-zynq-1/bin/arm-rtems6-gnatmake", "-D", 
> "testsuites/ada/tmtests/tm20", "-bargs", "-Mgnat_main", "-margs", 
> "-Icpukit/include/adainclude", 
> "-I../../../../src/rtems/cpukit/include/adainclude", 
> "-Itestsuites/ada/support", 
> "-I../../../../src/rtems/testsuites/ada/support", "-cargs", 
> "-march=armv7-a", "-mthumb", "-mfpu=neon", "-mfloat-abi=hard", 
> "-mtune=cortex-a9", "-largs", "testsuites/ada/tmtests/tm20/init.o", 
> "-Wl,--wrap=printf", "-Wl,--wrap=puts", "-Wl,--wrap=putchar", "-L.", 
> "-lrtemscpu", "-lrtemsbsp", "-lrtemstest", "-qrtems", "-march=armv7-a", 
> "-mthumb", "-mfpu=neon", "-mfloat-abi=hard", "-mtune=cortex-a9", 
> "-Wl,--gc-sections", 
> "-L/opt/rtems-6-zynq-1/src/rtems/bsps/arm/shared/start", 
> "-L/opt/rtems-6-zynq-1/src/rtems/bsps/arm/xilinx-zynq/start", "-margs", 
> "-a", 
> "/opt/rtems-6-zynq-1/src/rtems/testsuites/ada/tmtests/tm20/tm20.adb", 
> "-o", 
> "/opt/rtems-6-zynq-1/build/arm-xilinx_zynq_zc702-bsp-extra/arm/xilinx_zynq_zc702/testsuites/ada/ada_tm20.exe"], [] <unfinished ...>
> 
> [pid 110913] execve("/opt/rtems-6-zynq-1//bin/arm-rtems6-gcc", 
> ["/opt/rtems-6-zynq-1//bin/arm-rtems6-gcc", "-march=armv7-a", "-mthumb", 
> "-mfpu=neon", "-mfloat-abi=hard", "-mtune=cortex-a9", "-march=armv7-a", 
> "-mthumb", "-mfpu=neon", "-mfloat-abi=hard", "-mtune=cortex-a9", 
> "-print-multi-directory"], []) = 0
> 
> The above call is used to get the multi-lib directory. Which yields:
> 
> --RTS=thumb/armv7-a+simd/hard
> 
> The flags seem to be obtained by getting all "-m" flags from the 
> previous "-cargs" and "-largs". So, each flags appears twice.
> 
> [pid 110914] execve("/opt/rtems-6-zynq-1//bin/arm-rtems6-gnatbind", 
> ["/opt/rtems-6-zynq-1//bin/arm-rtems6-gnatbind", 
> "-aO/opt/rtems-6-zynq-1/build/arm-xilinx_zynq_zc702-bsp-extra/arm/xilinx_zynq_zc702/testsuites/ada/tmtests/tm20", "-Mgnat_main", "-Icpukit/include/adainclude", "-I../../../../src/rtems/cpukit/include/adainclude", "-Itestsuites/ada/support", "-I../../../../src/rtems/testsuites/ada/support", "--RTS=thumb/armv7-a+simd/hard", "-x", "/opt/rtems-6-zynq-1/build/arm-xilinx_zynq_zc702-bsp-extra/arm/xilinx_zynq_zc702/testsuites/ada/tmtests/tm20/tm20.ali"], []) = 0
> 
> [pid 110915] execve("/opt/rtems-6-zynq-1//bin/arm-rtems6-gnatlink", 
> ["/opt/rtems-6-zynq-1//bin/arm-rtems6-gnatlink", 
> "/opt/rtems-6-zynq-1/build/arm-xilinx_zynq_zc702-bsp-extra/arm/xilinx_zynq_zc702/testsuites/ada/tmtests/tm20/tm20.ali", "testsuites/ada/tmtests/tm20/init.o", "-Wl,--wrap=printf", "-Wl,--wrap=puts", "-Wl,--wrap=putchar", "-L.", "-lrtemscpu", "-lrtemsbsp", "-lrtemstest", "-qrtems", "-march=armv7-a", "-mthumb", "-mfpu=neon", "-mfloat-abi=hard", "-mtune=cortex-a9", "-Wl,--gc-sections", "-L/opt/rtems-6-zynq-1/src/rtems/bsps/arm/shared/start", "-L/opt/rtems-6-zynq-1/src/rtems/bsps/arm/xilinx-zynq/start", "-o", "/opt/rtems-6-zynq-1/build/arm-xilinx_zynq_zc702-bsp-extra/arm/xilinx_zynq_zc702/testsuites/ada/ada_tm20.exe"], []) = 0
> 
> Now the trouble starts, there is no longer a "-march=armv7-a" option:
> 
> [pid 110916] execve("/opt/rtems-6-zynq-1/bin/arm-rtems6-gcc", 
> ["/opt/rtems-6-zynq-1/bin/arm-rtems6-gcc", "-c", "-mthumb", 
> "-mfpu=neon", "-mfloat-abi=hard", "-mtune=cortex-a9", 
> "--RTS=thumb/armv7-a+simd/hard", "-gnatA", "-gnatWb", "-gnatiw", 
> "-gnatws", 
> "/opt/rtems-6-zynq-1/build/arm-xilinx_zynq_zc702-bsp-extra/arm/xilinx_zynq_zc702/b~tm20.adb"], []) = 0
> 
> Here a "-march=armv4t" pops up.
> 
> [pid 110917] 
> execve("/opt/rtems-6-zynq-1/lib/gcc/arm-rtems6/13.2.1/gnat1", 
> ["/opt/rtems-6-zynq-1/lib/gcc/arm-rtems6/13.2.1/gnat1", "-quiet", 
> "-dumpbase", "b~tm20.adb", "-dumpbase-ext", ".adb", "-mthumb", 
> "-mfpu=neon", "-mfloat-abi=hard", "-mtune=cortex-a9", 
> "-fRTS=thumb/armv7-a+simd/hard", "-gnatA", "-gnatWb", "-gnatiw", 
> "-gnatws", "-mcpu=arm7tdmi", "-mlibarch=armv4t", "-march=armv4t", 
> "-ftls-model=local-exec", 
> "/opt/rtems-6-zynq-1/build/arm-xilinx_zynq_zc702-bsp-extra/arm/xilinx_zynq_zc702/b~tm20.adb", "-o", "/tmp/ccZhtzF7.s"], ["COLLECT_GCC=/opt/rtems-6-zynq-1/bin/arm-rtems6-gcc", "COLLECT_GCC_OPTIONS='-c' '-mthumb' '-mfpu=neon' '-mfloat-abi=hard' '-mtune=cortex-a9' '-fRTS=thumb/armv7-a+simd/hard' '-gnatA' '-gnatWb' '-gnatiw' '-gnatws' '-mcpu=arm7tdmi' '-mlibarch=armv4t' '-march=armv4t'"] <unfinished ...>
> 
> Could someone give me a hint which component in GCC does this kind of 
> option processing and mapping?

It looks like the bogus options are loaded from a ALI file. The ALI file 
is produced by:

[pid 129509] 
execve("/opt/rtems-6-zynq-1/lib/gcc/arm-rtems6/13.2.1/gnat1", 
["/opt/rtems-6-zynq-1/lib/gcc/arm-rtems6/13.2.1/gnat1", "-I", 
"/opt/rtems-6-zynq-1/src/rtems/testsuites/ada/tmtests/tm21/", "-I", 
"cpukit/include/adainclude", "-I", 
"../../../../src/rtems/cpukit/include/adainclude", "-I", 
"testsuites/ada/support", "-I", 
"../../../../src/rtems/testsuites/ada/support", "-I", "-", "-quiet", 
"-dumpdir", 
"/opt/rtems-6-zynq-1/build/arm-xilinx_zynq_zc702-bsp-extra/arm/xilinx_zynq_zc702/testsuites/ada/tmtests/tm21/", 
"-dumpbase", "tm21.adb", "-dumpbase-ext", ".adb", "-gnatez", "-gnatea", 
"-mthumb", "-mfpu=neon", "-mfloat-abi=hard", "-mtune=cortex-a9", 
"-fRTS=thumb/armv7-a+simd/hard", "-gnatez", "-mlibarch=armv7-a+simd", 
"-march=armv7-a+simd", "-ftls-model=local-exec", "-gnatO", 
"/opt/rtems-6-zynq-1/build/arm-xilinx_zynq_zc702-bsp-extra/arm/xilinx_zynq_zc702/testsuites/ada/tmtests/tm21/tm21.o", 
"/opt/rtems-6-zynq-1/src/rtems/testsuites/ada/tmtests/tm21/tm21.adb", 
"-o", "/tmp/ccK4c8JY.s"], [..., 
"COLLECT_GCC=/opt/rtems-6-zynq-1//bin/arm-rtems6-gcc", 
"COLLECT_GCC_OPTIONS='-gnatea' '-c' '-I' 
'/opt/rtems-6-zynq-1/src/rtems/testsuites/ada/tmtests/tm21/' '-I' 
'cpukit/include/adainclude' '-I' 
'../../../../src/rtems/cpukit/include/adainclude' '-I' 
'testsuites/ada/support' '-I' 
'../../../../src/rtems/testsuites/ada/support'  '-mthumb' '-mfpu=neon' 
'-mfloat-abi=hard' '-mtune=cortex-a9' '-fRTS=thumb/armv7-a+simd/hard' 
'-I' '-' '-o' 
'/opt/rtems-6-zynq-1/build/arm-xilinx_zynq_zc702-bsp-extra/arm/xilinx_zynq_zc702/testsuites/ada/tmtests/tm21/tm21.o' 
'-gnatez' '-mlibarch=armv7-a+simd' '-march=armv7-a+simd' '-dumpdir' 
'/opt/rtems-6-zynq-1/build/arm-xilinx_zynq_zc702-bsp-extra/arm/xilinx_zynq_zc702/testsuites/ada/tmtests/tm21/'"] 
<unfinished ...>

This command has all the required options. It writes an ALI file:

[pid 129509] 
unlink("/opt/rtems-6-zynq-1/build/arm-xilinx_zynq_zc702-bsp-extra/arm/xilinx_zynq_zc702/testsuites/ada/tmtests/tm21/tm21.ali") 
= -1 ENOENT (No such file or directory)
[pid 129509] openat(AT_FDCWD, 
"/opt/rtems-6-zynq-1/build/arm-xilinx_zynq_zc702-bsp-extra/arm/xilinx_zynq_zc702/testsuites/ada/tmtests/tm21/tm21.ali", 
O_WRONLY|O_CREAT|O_TRUNC, 0666) = 4

In this file not all required machine options are stored:

head 
/opt/rtems-6-zynq-1/build/arm-xilinx_zynq_zc702-bsp-extra/arm/xilinx_zynq_zc702/testsuites/ada/tmtests/tm21/tm21.ali
V "GNAT Lib v13"
M P W=b
A -mthumb
A -mfpu=neon
A -mfloat-abi=hard
A -mtune=cortex-a9
A --RTS=thumb/armv7-a+simd/hard
P ZX

RN

The "-march=armv7-a+simd" is missing.

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