Hi Carlos,
again apologies for updating this so late. It appears that there's not a lot of problems
from the last round of review, so hope this is still in time.

On 2020/6/19 5:30 AM, Carlos O'Donell wrote:
>> diff --git a/elf/dso-sort-tests-1.def b/elf/dso-sort-tests-1.def
>> new file mode 100644
>> index 0000000000..d94c6eda87
>> --- /dev/null
>> +++ b/elf/dso-sort-tests-1.def
>> @@ -0,0 +1,30 @@
> We should have some comments explaing what each test does.
> 
> # 1. Sequence of signle dependencies with no cycles.
> 
>> +tst-dso-ordering1: a->b->c
>> +output: c>b>a>{}<a<b<c

I have added comments to each testcase description, a combination of what you
wrote and my own wording.

>> +tst-bz15311: {+a;+e;+f;+g;+d;%d;-d;-g;-f;-e;-a};a->b->c->d;d=>[ba];c=>a;b=>e=>a;c=>f=>b;d=>g=>c
> The test case us underlinked and the right solution for a program
> doing this would be to fix all the underlinking. However, we keep
> the test case here to ensure validity of the pre/post sorting for
> underlinked unspecified cases.

As well as a slightly longer description for the #15311 test. Basically the expected orders
here are just to record behavior, for regression comparison.

>> +output(glibc.rtld.dynamic_sort=1): {+a[d>c>b>a>];+e[e>];+f[f>];+g[g>];+d[];%d(b(e(a()))a()g(c(a()f(b(e(a()))))));-d[];-g[];-f[];-e[];-a[<a<c<d<g<f<b<e];}
>> +output(glibc.rtld.dynamic_sort=2): {+a[d>c>b>a>];+e[e>];+f[f>];+g[g>];+d[];%d(b(e(a()))a()g(c(a()f(b(e(a()))))));-d[];-g[];-f[];-e[];-a[<g<f<a<b<c<d<e];}
> We need a comment explaining the two sorting orders and why we end up at each one.

>> diff --git a/elf/dso-sort-tests-2.def b/elf/dso-sort-tests-2.def
>> new file mode 100644
>> index 0000000000..39c6acbaf2
>> --- /dev/null
>> +++ b/elf/dso-sort-tests-2.def
>> @@ -0,0 +1,605 @@
>> +tst-redhat-1162810:
>> +{}->A101
>> +{}->*
>> +A101->(B101 B163 B122 B181)
>> +A102->(B102 B140 B199 B158)
>> +A103->(B103 B117 B176 B135)
>> +A104->(B104 B194 B153 B112)
>> +A105->(B105 B171 B130 B189)
...
>> +M30X23
>> +M30X24
>> +M30X25
>> +output(glibc.rtld.dynamic_sort=1): M30X19>M30X15>M30X16>M30X11>M30X12>M30X17>M30X13>M30X14>M29X20>M30X23>M30X24>M30X20>M30X18>M29X15>M29X12>M30X22>M30X21>M29X22>M30X25>M29X19>M29X23>M29X16>M29X24>M29X13>M29X17>M29X18>M28X19>M29X21>M29X25>M29X14>M28X20>M28X15>M28X16>M28X21>M27X18>M29X11>M28X17>M28X11>M28X22>M27X14>M28X18>M27X15>M28X13>M27X11>M28X23>M27X25>M28X14>M28X25>M27X23>M27X22>M28X24>M27X21>M27X13>M27X19>M27X17>M26X11>M26X23>M26X21>M26X22>M26X20>M26X16>M25X21>M17X22>M15X15>M20X14>M20X16>M18X18>M28X12>M27X24>M25X17>M27X20>M26X18>M26X17>M27X16>M26X19>M25X18>M26X24>M25X20>M24X17>M23X18>M25X13>M26X13>M17X23>M16X16>M26X12>M25X12>M26X15>M24X19>M25X23>M25X24>M25X25>M24X20>M25X19>M24X21>M23X17>M22X21>M24X14>M23X22>M24X24>M22X20>M24X13>M25X11>M24X12>M25X15>M23X15>M25X16>M24X22>M23X13>M24X18>M23X14>M22X22>M21X20>M24X25>M23X16>M22X25>M21X19>M22X14>M23X11>M22X15>M21X18>M22X19>M21X17>M20X17>M19X17>M21X24>M21X12>M20X22>M19X16>M18X25>M19X21>M19X20>M18X24>M20X12>M19X11>M23X20>M22X24>M22X16>M21X21>M25X14>M23X19>M23X24>M20X24>M19X12>M18X15>M17X14>M16X18>M14X25>M16X22>M16X20>M17X17>M22X12>M21X11>M20X15>M18X22>M19X24>M19X18>M18X21>M17X16>M17X18>M16X21>M15X20>M19X22>M18X20>M18X11>M17X19>M16X17>M15X21>M16X14>M16X13>M15X22>M14X20>M17X25>M16X19>M14X21>M13X24>M12X12>M16X24>M15X23>M14X16>M16X15>M15X25>M15X11>M15X12>M14X15>M13X14>M14X22>M13X20>M12X13>M11X11>M22X23>M21X15>M21X16>M20X21>M20X20>M18X17>M19X25>M18X23>M21X13>M15X17>M15X18>M18X19>M17X24>M16X12>M17X13>M20X25>M19X23>M15X19>M14X13>M13X18>M15X13>M17X12>M16X11>M18X13>M18X12>M14X11>M14X24>M13X19>M15X14>M17X20>M20X11>M20X13>M21X14>M15X24>M14X12>M13X22>M14X23>M13X23>M14X19>M17X15>M16X25>M17X11>M18X14>M19X19>M21X25>M13X12>M13X11>M14X18>M13X13>M12X11>M15X16>M14X14>M27X12>M17X21>M20X23>M22X13>M21X22>M24X16>M24X15>M26X25>M23X25>M26X14>M23X12>M22X18>M24X11>M16X23>M19X14>M19X13>M21X23>M22X17>M23X23>M23X21>M25X22>M18X16>M19X15>M20X18>M20X19>M22X11>M24X23>C156>C118>C143>C137>C147>C106>C168>C113>C163>C155>C105>C146>C187>A150>C139>C180>C164>C193>C157>A191>C158>B188>A159>C184>C121>C154>B171>A105>C131>C104>B104>C161>C111>B145>C160>B155>A163>C112>C142>B148>C133>B198>A198>A115>C114>B157>A156>C175>B144>A120>C173>B184>A174>C126>B107>A139>C194>B194>A194>C116>B116>C166>B160>B110>A110>C128>B128>A128>C179>B162>A154>C186>B187>A179>C124>B181>A101>C153>B158>A136>C135>C176>A192>B133>A133>C177>B177>A177>C185>C103>B141>A141>C183>A162>C192>C129>B179>C144>B124>B183>C127>B127>A127>B108>A112>B153>A153>C167>B167>A186>A122>C162>A144>B149>C174>B131>A185>C141>B106>A126>A167>C140>B122>A170>C198>B143>C117>C123>B123>A147>A106>C200>B169>C191>B175>A123>B118>A182>C132>B151>A145>A104>A109>C159>C150>B119>A119>A178>B164>B114>A164>C181>A102>C122>B134>A157>A116>C195>B191>B111>C172>B172>A118>B129>A129>C149>A107>C170>B197>A197>A173>B168>A132>C107>B165>A160>A131>C188>A168>B109>C178>A189>A148>C119>C190>C120>B166>B176>C108>B135>B139>A103>B178>A169>B132>C125>C138>B163>A111>B170>C110>A165>C151>C169>C199>A138>C182>A135>B101>B142>C101>C148>B193>B152>A158>A199>C136>B137>A161>B120>A108>A149>A125>B113>A184>C171>A134>A175>A124>B150>B161>B102>A146>A187>C130>B192>B200>A200>A142>A183>C102>B105>B156>A176>C165>B147>A137>A196>B190>A190>B125>C134>C189>B126>B186>A166>B136>B195>A195>B154>B138>B112>B173>A117>B159>B182>A181>A140>C145>B117>A152>A193>C197>B130>A172>A113>A151>B115>A143>B140>B185>B103>A121>A180>A130>A171>B199>C196>B146>B180>C115>B174>B121>A188>B196>B189>C152>C109>A155>A114>M14X17>M13X15>M13X16>M13X17>M12X17>M12X21>M12X25>M12X14>M13X25>M12X15>M13X21>M12X16>M12X18>M12X19>M12X20>M12X22>M12X23>M12X24>M11X25>M11X24>M11X23>M11X22>M11X21>M11X20>M11X19>M11X18>M11X17>M11X16>M11X15>M11X14>M11X13>M11X12>{}<M11X12<M11X13<M11X14<M11X15<M11X16<M11X17<M11X18<M11X19<M11X20<M11X21<M11X22<M11X23<M11X24<M11X25<M12X24<M12X23<M12X22<M12X20<M12X19<M12X18<M12X16<M13X21<M12X15<M13X25<M12X14<M12X25<M12X21<M12X17<M13X17<M13X16<M13X15<M14X17<A114<A155<C109<C152<B189<B196<A188<B121<B174<C115<B180<B146<C196<B199<A171<A130<A180<A121<B103<B185<B140<A143<B115<A151<A113<A172<B130<C197<A193<A152<B117<C145<A140<A181<B182<B159<A117<B173<B112<B138<B154<A195<B195<B136<A166<B186<B126<C189<C134<B125<A190<B190<A196<A137<B147<C165<A176<B156<B105<C102<A183<A142<A200<B200<B192<C130<A187<A146<B102<B161<B150<A124<A175<A134<C171<A184<B113<A125<A149<A108<B120<A161<B137<C136<A199<A158<B152<B193<C148<C101<B142<B101<A135<C182<A138<C199<C169<C151<A165<C110<B170<A111<B163<C138<C125<B132<A169<B178<A103<B139<B135<C108<B176<B166<C120<C190<C119<A148<A189<C178<B109<A168<C188<A131<A160<B165<C107<A132<B168<A173<A197<B197<C170<A107<C149<A129<B129<A118<B172<C172<B111<B191<C195<A116<A157<B134<C122<A102<C181<A164<B114<B164<A178<A119<B119<C150<C159<A109<A104<A145<B151<C132<A182<B118<A123<B175<C191<B169<C200<A106<A147<B123<C123<C117<B143<C198<A170<B122<C140<A167<A126<B106<C141<A185<B131<C174<B149<A144<C162<A122<A186<B167<C167<A153<B153<A112<B108<A127<B127<C127<B183<B124<C144<B179<C129<C192<A162<C183<A141<B141<C103<C185<A177<B177<C177<A133<B133<A192<C176<C135<A136<B158<C153<A101<B181<C124<A179<B187<C186<A154<B162<C179<A128<B128<C128<A110<B110<B160<C166<B116<C116<A194<B194<C194<A139<B107<C126<A174<B184<C173<A120<B144<C175<A156<B157<C114<A115<A198<B198<C133<B148<C142<C112<A163<B155<C160<B145<C111<C161<B104<C104<C131<A105<B171<C154<C121<C184<A159<B188<C158<A191<C157<C193<C164<C180<C139<A150<C187<C146<C105<C155<C163<C113<C168<C106<C147<C137<C143<C118<C156<M24X23<M22X11<M20X19<M20X18<M19X15<M18X16<M25X22<M23X21<M23X23<M22X17<M21X23<M19X13<M19X14<M16X23<M24X11<M22X18<M23X12<M26X14<M23X25<M26X25<M24X15<M24X16<M21X22<M22X13<M20X23<M17X21<M27X12<M14X14<M15X16<M12X11<M13X13<M14X18<M13X11<M13X12<M21X25<M19X19<M18X14<M17X11<M16X25<M17X15<M14X19<M13X23<M14X23<M13X22<M14X12<M15X24<M21X14<M20X13<M20X11<M17X20<M15X14<M13X19<M14X24<M14X11<M18X12<M18X13<M16X11<M17X12<M15X13<M13X18<M14X13<M15X19<M19X23<M20X25<M17X13<M16X12<M17X24<M18X19<M15X18<M15X17<M21X13<M18X23<M19X25<M18X17<M20X20<M20X21<M21X16<M21X15<M22X23<M11X11<M12X13<M13X20<M14X22<M13X14<M14X15<M15X12<M15X11<M15X25<M16X15<M14X16<M15X23<M16X24<M12X12<M13X24<M14X21<M16X19<M17X25<M14X20<M15X22<M16X13<M16X14<M15X21<M16X17<M17X19<M18X11<M18X20<M19X22<M15X20<M16X21<M17X18<M17X16<M18X21<M19X18<M19X24<M18X22<M20X15<M21X11<M22X12<M17X17<M16X20<M16X22<M14X25<M16X18<M17X14<M18X15<M19X12<M20X24<M23X24<M23X19<M25X14<M21X21<M22X16<M22X24<M23X20<M19X11<M20X12<M18X24<M19X20<M19X21<M18X25<M19X16<M20X22<M21X12<M21X24<M19X17<M20X17<M21X17<M22X19<M21X18<M22X15<M23X11<M22X14<M21X19<M22X25<M23X16<M24X25<M21X20<M22X22<M23X14<M24X18<M23X13<M24X22<M25X16<M23X15<M25X15<M24X12<M25X11<M24X13<M22X20<M24X24<M23X22<M24X14<M22X21<M23X17<M24X21<M25X19<M24X20<M25X25<M25X24<M25X23<M24X19<M26X15<M25X12<M26X12<M16X16<M17X23<M26X13<M25X13<M23X18<M24X17<M25X20<M26X24<M25X18<M26X19<M27X16<M26X17<M26X18<M27X20<M25X17<M27X24<M28X12<M18X18<M20X16<M20X14<M15X15<M17X22<M25X21<M26X16<M26X20<M26X22<M26X21<M26X23<M26X11<M27X17<M27X19<M27X13<M27X21<M28X24<M27X22<M27X23<M28X25<M28X14<M27X25<M28X23<M27X11<M28X13<M27X15<M28X18<M27X14<M28X22<M28X11<M28X17<M29X11<M27X18<M28X21<M28X16<M28X15<M28X20<M29X14<M29X25<M29X21<M28X19<M29X18<M29X17<M29X13<M29X24<M29X16<M29X23<M29X19<M30X25<M29X22<M30X21<M30X22<M29X12<M29X15<M30X18<M30X20<M30X24<M30X23<M29X20<M30X14<M30X13<M30X17<M30X12<M30X11<M30X16<M30X15<M30X19
>> +output(glibc.rtld.dynamic_sort=2): M30X19>M30X15>M30X16>M30X11>M30X12>M30X17>M30X13>M30X14>M29X20>M30X23>M30X24>M30X20>M30X18>M29X15>M29X12>M30X22>M30X21>M29X22>M30X25>M29X19>M29X23>M29X16>M29X24>M29X13>M29X17>M29X18>M28X19>M29X21>M29X25>M29X14>M28X20>M28X15>M28X16>M28X21>M27X18>M29X11>M28X17>M28X11>M28X22>M28X24>M28X23>M27X21>M28X13>M27X20>M27X19>M26X14>M27X25>M28X18>M27X11>M28X25>M27X24>M26X24>M27X15>M27X14>M27X13>M26X23>M27X17>M26X22>M25X13>M28X14>M27X16>M26X19>M26X18>M27X23>M27X22>M26X17>M25X18>M26X21>M25X17>M26X20>M26X15>M26X13>M25X19>M24X14>M25X23>M26X11>M26X25>M25X16>M25X15>M24X22>M25X21>M25X20>M24X21>M25X25>M25X24>M24X20>M23X13>M22X15>M25X14>M24X19>M23X17>M24X25>M23X24>M24X13>M23X15>M24X18>M23X14>M22X11>M24X15>M23X22>M24X11>M23X19>M22X21>M24X24>M23X21>M22X20>M23X25>M22X19>M21X24>M20X23>M22X22>M25X11>M23X16>M22X18>M23X20>M22X17>M21X21>M21X20>M20X24>M22X14>M22X13>M21X11>M21X17>M22X23>M21X16>M20X25>M19X23>M18X16>M21X22>M20X20>M20X19>M21X13>M20X18>M19X13>M21X18>M20X21>M19X24>M18X12>M20X14>M20X13>M22X25>M20X12>M20X15>M19X14>M18X22>M19X18>M20X17>M19X17>M19X16>M18X21>M17X20>M19X19>M18X13>M17X11>M18X17>M19X25>M18X15>M17X25>M18X19>M17X24>M16X19>M15X17>M17X21>M16X24>M18X23>M17X16>M16X25>M19X15>M18X25>M17X23>M16X23>M15X23>M18X14>M17X14>M16X14>M17X18>M16X13>M17X22>M16X12>M15X22>M14X16>M17X12>M16X22>M15X12>M16X11>M15X11>M16X15>M15X25>M14X15>M13X14>M15X18>M16X21>M15X16>M14X21>M15X14>M16X20>M15X13>M14X22>M15X20>M14X20>M13X20>M14X11>M15X19>M14X24>M13X19>M14X13>M13X18>M12X13>M15X24>M14X23>M13X12>M14X12>M13X11>M12X11>M11X11>M21X12>M20X11>M19X11>M18X11>M17X15>M16X18>M14X25>M14X19>M13X24>M13X23>M13X22>M12X12>M22X12>M21X15>M19X22>M18X20>M16X17>M14X14>M24X12>M23X23>M22X16>M21X14>M20X22>M18X24>M16X16>M26X12>M24X16>M23X11>M21X23>M19X20>M17X17>M27X12>M26X16>M25X22>M24X17>M23X18>M21X25>M19X12>M17X19>M15X21>M14X18>M13X13>M23X12>M21X19>M19X21>M17X13>M15X15>M25X12>M24X23>M22X24>M20X16>M18X18>M28X12>A150>C158>B112>A112>C167>B146>A146>C180>B180>A180>C143>B143>A115>C126>B126>A126>C190>B190>A190>C138>B138>A138>C174>B174>A102>C122>B122>A122>C162>B162>A162>C142>B142>A142>C102>B102>A174>C176>B176>A176>C115>B115>A143>C172>B172>A172>C187>B187>A187>C130>B130>A130>C118>B118>A118>C184>B184>A184>C171>B171>A171>C168>B182>A182>C182>B168>A168>C109>B109>A109>C159>B159>A159>C134>B134>A134>C146>B167>A167>C140>B140>A140>C163>B163>A163>C112>B158>A158>C164>B164>A164>C131>B131>A131>C188>B188>A188>C199>B199>A199>C114>B114>A114>C106>B106>A106>C200>B200>A200>C183>B183>A183>C152>B152>A152>C147>B147>A147>C150>B150>A198>C144>B144>A144>C191>B191>A191>C108>B108>A108>C139>B139>A139>C194>B194>A194>C166>B166>A166>C120>B120>A120>C123>B123>A123>C132>B132>A132>C107>B107>A107>C170>B170>A170>C198>B198>A156>C125>B125>A125>C121>B121>A121>C193>B193>A193>C197>B197>A197>C175>B175>A175>C196>B196>A196>C105>B105>A105>C181>B181>A181>C113>B113>A113>C137>B137>A137>C155>B155>A155>C156>B156>A110>C128>B128>A128>C179>B179>A179>C124>B124>A124>C151>B151>A151>C178>B178>A178>C104>B104>A104>C111>B111>A111>C148>B148>A148>C169>B169>A169>C129>B129>A129>C149>B149>A149>C189>B189>A189>C119>B119>A119>C154>B154>A154>C136>B136>A136>C135>B135>A135>C116>B116>A116>C145>B145>A145>C161>B161>A161>C173>B173>A173>C157>B157>A157>C195>B195>A195>C186>B186>A186>C160>B160>A160>C153>B153>A153>C117>B117>A117>C165>B165>A165>C101>B101>A101>C103>B103>A103>C192>B192>A192>C177>B177>A177>C185>B185>A185>C141>B141>A141>C133>B133>A133>C127>B127>A127>C110>B110>M14X17>M13X15>M13X16>M13X17>M12X17>M12X21>M12X25>M12X14>M13X25>M12X15>M13X21>M12X16>M12X18>M12X19>M12X20>M12X22>M12X23>M12X24>M11X25>M11X24>M11X23>M11X22>M11X21>M11X20>M11X19>M11X18>M11X17>M11X16>M11X15>M11X14>M11X13>M11X12>{}<M11X12<M11X13<M11X14<M11X15<M11X16<M11X17<M11X18<M11X19<M11X20<M11X21<M11X22<M11X23<M11X24<M11X25<M12X24<M12X23<M12X22<M12X20<M12X19<M12X18<M12X16<M13X21<M12X15<M13X25<M12X14<M12X25<M12X21<M12X17<M13X17<M13X16<M13X15<M14X17<B110<C110<A127<B127<C127<A133<B133<C133<A141<B141<C141<A185<B185<C185<A177<B177<C177<A192<B192<C192<A103<B103<C103<A101<B101<C101<A165<B165<C165<A117<B117<C117<A153<B153<C153<A160<B160<C160<A186<B186<C186<A195<B195<C195<A157<B157<C157<A173<B173<C173<A161<B161<C161<A145<B145<C145<A116<B116<C116<A135<B135<C135<A136<B136<C136<A154<B154<C154<A119<B119<C119<A189<B189<C189<A149<B149<C149<A129<B129<C129<A169<B169<C169<A148<B148<C148<A111<B111<C111<A104<B104<C104<A178<B178<C178<A151<B151<C151<A124<B124<C124<A179<B179<C179<A128<B128<C128<A110<B156<C156<A155<B155<C155<A137<B137<C137<A113<B113<C113<A181<B181<C181<A105<B105<C105<A196<B196<C196<A175<B175<C175<A197<B197<C197<A193<B193<C193<A121<B121<C121<A125<B125<C125<A156<B198<C198<A170<B170<C170<A107<B107<C107<A132<B132<C132<A123<B123<C123<A120<B120<C120<A166<B166<C166<A194<B194<C194<A139<B139<C139<A108<B108<C108<A191<B191<C191<A144<B144<C144<A198<B150<C150<A147<B147<C147<A152<B152<C152<A183<B183<C183<A200<B200<C200<A106<B106<C106<A114<B114<C114<A199<B199<C199<A188<B188<C188<A131<B131<C131<A164<B164<C164<A158<B158<C112<A163<B163<C163<A140<B140<C140<A167<B167<C146<A134<B134<C134<A159<B159<C159<A109<B109<C109<A168<B168<C182<A182<B182<C168<A171<B171<C171<A184<B184<C184<A118<B118<C118<A130<B130<C130<A187<B187<C187<A172<B172<C172<A143<B115<C115<A176<B176<C176<A174<B102<C102<A142<B142<C142<A162<B162<C162<A122<B122<C122<A102<B174<C174<A138<B138<C138<A190<B190<C190<A126<B126<C126<A115<B143<C143<A180<B180<C180<A146<B146<C167<A112<B112<C158<A150<M28X12<M18X18<M20X16<M22X24<M24X23<M25X12<M15X15<M17X13<M19X21<M21X19<M23X12<M13X13<M14X18<M15X21<M17X19<M19X12<M21X25<M23X18<M24X17<M25X22<M26X16<M27X12<M17X17<M19X20<M21X23<M23X11<M24X16<M26X12<M16X16<M18X24<M20X22<M21X14<M22X16<M23X23<M24X12<M14X14<M16X17<M18X20<M19X22<M21X15<M22X12<M12X12<M13X22<M13X23<M13X24<M14X19<M14X25<M16X18<M17X15<M18X11<M19X11<M20X11<M21X12<M11X11<M12X11<M13X11<M14X12<M13X12<M14X23<M15X24<M12X13<M13X18<M14X13<M13X19<M14X24<M15X19<M14X11<M13X20<M14X20<M15X20<M14X22<M15X13<M16X20<M15X14<M14X21<M15X16<M16X21<M15X18<M13X14<M14X15<M15X25<M16X15<M15X11<M16X11<M15X12<M16X22<M17X12<M14X16<M15X22<M16X12<M17X22<M16X13<M17X18<M16X14<M17X14<M18X14<M15X23<M16X23<M17X23<M18X25<M19X15<M16X25<M17X16<M18X23<M16X24<M17X21<M15X17<M16X19<M17X24<M18X19<M17X25<M18X15<M19X25<M18X17<M17X11<M18X13<M19X19<M17X20<M18X21<M19X16<M19X17<M20X17<M19X18<M18X22<M19X14<M20X15<M20X12<M22X25<M20X13<M20X14<M18X12<M19X24<M20X21<M21X18<M19X13<M20X18<M21X13<M20X19<M20X20<M21X22<M18X16<M19X23<M20X25<M21X16<M22X23<M21X17<M21X11<M22X13<M22X14<M20X24<M21X20<M21X21<M22X17<M23X20<M22X18<M23X16<M25X11<M22X22<M20X23<M21X24<M22X19<M23X25<M22X20<M23X21<M24X24<M22X21<M23X19<M24X11<M23X22<M24X15<M22X11<M23X14<M24X18<M23X15<M24X13<M23X24<M24X25<M23X17<M24X19<M25X14<M22X15<M23X13<M24X20<M25X24<M25X25<M24X21<M25X20<M25X21<M24X22<M25X15<M25X16<M26X25<M26X11<M25X23<M24X14<M25X19<M26X13<M26X15<M26X20<M25X17<M26X21<M25X18<M26X17<M27X22<M27X23<M26X18<M26X19<M27X16<M28X14<M25X13<M26X22<M27X17<M26X23<M27X13<M27X14<M27X15<M26X24<M27X24<M28X25<M27X11<M28X18<M27X25<M26X14<M27X19<M27X20<M28X13<M27X21<M28X23<M28X24<M28X22<M28X11<M28X17<M29X11<M27X18<M28X21<M28X16<M28X15<M28X20<M29X14<M29X25<M29X21<M28X19<M29X18<M29X17<M29X13<M29X24<M29X16<M29X23<M29X19<M30X25<M29X22<M30X21<M30X22<M29X12<M29X15<M30X18<M30X20<M30X24<M30X23<M29X20<M30X14<M30X13<M30X17<M30X12<M30X11<M30X16<M30X15<M30X19
> Again, I think we need a comment here explaining the salient differences
> between the two sort algorithms and why the second is desirable in this case.

Same as for RH-1162810. When you have circular dependencies, you can get this kind of variance in behavior
among different algorithms.

>> diff --git a/scripts/dso-ordering-test.py b/scripts/dso-ordering-test.py
>> new file mode 100644
>> index 0000000000..6e2e36ab87
>> --- /dev/null
>> +++ b/scripts/dso-ordering-test.py
>> @@ -0,0 +1,947 @@
>> +#!/usr/bin/python3
>> +# Generate testcase files and Makefile fragments for DSO sorting test
>> +# Copyright (C) 2020 Free Software Foundation, Inc.
>> +# This file is part of the GNU C Library.
...

>> +different link line orders: "b.so c.so d.so", "c.so b.so d.so",
>> +"b.so d.so c.so", etc. Note that for a <test-name> specified on
>> +the script command-line, multiple <test-name_1>, <test-name_2>, etc.
>> +tests will be generated (e.g. for a!->[bc]!->[de], eight tests with
>> +different link orders for a, b, and c will be generated)
> Can we please get a little more comments explaining the test output?
> The test input is specified well, but some examples of test output
> and what they mean would go a long way to helping new developers
> understand the DSL.

I've added another section "Strings Output by Generated Testcase Programs" in the
script comments, hope this is enough.

>> +    # Some debug output
>> +    if cmdlineargs.debug_output:
>> +        print ("Testcase: %s" % (t.test_name))
>> +        print ("All objects: %s" % (t.objs))
>> +        print ("--- Static link dependencies ---")
>> +        for r in t.deps.items():
>> +            print ("%s -> %s" % (r[0], r[1]))
>> +        print ("--- Objects whose dependencies are to be permutated ---")
> s/permutated/permuted/g

I only now notice that "permute" vs "permutate" is an issue :) I've corrected the
spelling as you've suggested.

The v3 patch is attached, please see if this is now okay for committing.

Thanks,
Chung-Lin