This was discussed in D93678 thread.
Currently we have one special chunk - Fill.
This patch re implements the "SectionHeaderTable" key to become a special chunk too.
With that we are able to place the section header table at any location,
just like we place sections.
Differential revision: https://reviews.llvm.org/D95140
Imagine we have a YAML declaration of few sections: `foo1`, `<unnamed 2>`, `foo3`, `foo4`.
To put them into segment we can do (1*):
```
Sections:
- Section: foo1
- Section: foo4
```
or we can use (2*):
```
Sections:
- Section: foo1
- Section: foo3
- Section: foo4
```
or (3*) :
```
Sections:
- Section: foo1
## "(index 2)" here is a name that we automatically created for a unnamed section.
- Section: (index 2)
- Section: foo3
- Section: foo4
```
It looks really confusing that we don't have to list all of sections.
At first I've tried to make this rule stricter and report an error when there is a gap
(i.e. when a section is included into segment, but not listed explicitly).
This did not work perfect, because such approach conflicts with unnamed sections/fills (see (3*)).
This patch drops "Sections" key and introduces 2 keys instead: `FirstSec` and `LastSec`.
Both are optional.
Differential revision: https://reviews.llvm.org/D90458
The current situation/behavior is:
1) llvm-readelf doesn't need a string that is specified by `DT_SONAME`.
2) llvm-readobj/elf always tries to read it, even when there is no `DT_SONAME` tag.
3) Because of that both tools reports a warning for many our test cases.
This patch delays getting a SOName string and changes the behavior (llvm-readobj) to
only report a warning when there is a `DT_SONAME` and a string cab't be read.
Warning is not reported for llvm-readelf, as it never tries to dump it.
Differential revision: https://reviews.llvm.org/D89384
Specification for `SHT_HASH` table says (https://refspecs.linuxbase.org/elf/gabi4+/ch5.dynamic.html#hash)
that it contains `Elf32_Word` entries for both `32/64` bit objects.
But there is a problem with `EM_S390` and `ELF::EM_ALPHA` platforms: they use 8-bytes entries.
(see the issue reported: https://bugs.llvm.org/show_bug.cgi?id=47681).
Currently we might infer the size of the dynamic symbols table from hash table,
but because of the issue mentioned, the calculation is wrong. And also we don't dump the hash table
properly.
I am not sure if we want to support 8-bytes entries as they violates specification and also the
`.hash` table is kind of deprecated by itself (the `.gnu.hash` table is used nowadays).
So, the solution this patch suggests is to ban using of the hash table on `EM_S390/EM_ALPHA` platforms.
Differential revision: https://reviews.llvm.org/D88817
This makes tests stricter and adds cases to verify what
we do when:
1) there is no `DT_HASH` tag (but there is a `SHT_HASH` section in sections header)
2) the sh_entsize of the `SHT_HASH` section is not equal to 4.
Differential revision: https://reviews.llvm.org/D88812
Currently we might derive the dynamic symbol table size from the DT_HASH hash table (using its `nchain` field).
It is possible to crash dumpers with a broken relocation that refers to a symbol with an index
that is too large. To trigger it, the inferred size of the dynamic symbol table should go past the end of the object.
This patch adds a size validation + warning.
Differential revision: https://reviews.llvm.org/D86923
Currently we have to set 'Machine' to something in our
YAML descriptions. Usually we use 'EM_X86_64' for 64-bit targets
and 'EM_386' for 32-bit targets. At the same time, in fact, in most
cases our tests do not need a machine type and we can use
'EM_NONE'.
This is cleaner, because avoids the need of using a particular machine.
In this patch I've made the 'Machine' key optional (the default value,
when it is not specified is `EM_NONE`) and removed it (where possible)
from yaml2obj, obj2yaml and llvm-readobj tests.
There are few tests left where I decided not to remove it, because
I didn't want to touch CHECK lines or doing anything more complex
than a removing a "Machine: *" line and formatting lines around.
Differential revision: https://reviews.llvm.org/D86202
In D83482 we agreed to name e_* fields that are used for overriding
values (like e_phoff) as EPh* (e.g. EPhOff).
Currently we have a set of e_sh* fields that are named inconsistently
with this rule. This patch renames all of them.
Differential revision: https://reviews.llvm.org/D83766
This improves the next points for broken hash tables:
1) Use reportUniqueWarning to prevent duplication when
--hash-table and --elf-hash-histogram are used together.
2) Dump nbuckets and nchain fields. It is often possible
to dump them even when the table itself goes past the EOF etc.
Differential revision: https://reviews.llvm.org/D80373
We have scenarios when the logic of --elf-hash-histogram/--hash-symbols/--hash-table
options might crash when given a broken hash table.
This patch adds pre-checks for tables for these 3 options
and provides test cases.
Differential revision: https://reviews.llvm.org/D77147
We had no test for --hash-table in tools/llvm-readobj.
The one we had was in test/Object and checked that
it is possible to dump the hash table even when an object
doesn't have a section header table.
In this patch I created a test, moved and merged the existent one.
During moving I converted it to be YAML based to stop using the
precompiled binary.
Differential revision: https://reviews.llvm.org/D73105
Georgii Rymar