Commit Graph

6 Commits

Author SHA1 Message Date
Georgii Rymar a7a447be0f [yaml2obj] - ProgramHeaders: introduce FirstSec/LastSec instead of Sections list.
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
2020-11-09 13:00:50 +03:00
Georgii Rymar ef4851742d [llvm-readobj][test] - Address a forgotten review comment for D86923.
Seems I've forgot to address this bit and this looks like a reason
of a failture on mac (http://45.33.8.238/mac/20491/step_11.txt).
2020-09-16 11:51:26 +03:00
Georgii Rymar 7df873f9c6 [llvm-readobj/elf] - Don't crash when the size of s dynamic symbol table, inferred from the hash table, is broken.
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
2020-09-15 17:44:16 +03:00
Georgii Rymar a6436b0b3a [yaml2obj] - Make the 'Machine' key optional.
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
2020-08-20 11:40:51 +03:00
Georgii Rymar 61f967dcca [llvm-readobj] - Don't crash when checking the number of dynamic symbols.
When we deriving the number of symbols from the DT_HASH table, we can crash when
calculate the number of symbols in the symbol table when SHT_DYNSYM
has sh_entsize == 0.

The patch fixes the issue.

Differential revision: https://reviews.llvm.org/D82877
2020-07-01 12:14:10 +03:00
James Henderson b259ce998f [llvm-readobj] Derive dynamic symtab size from DT_HASH
If the section headers have been removed by a tool such as llvm-objcopy
or llvm-strip, previously llvm-readobj/llvm-readelf would not dump the
dynamic symbols when --dyn-symbols was specified. However, the nchain
value of the DT_HASH data specifies the number of dynamic symbols, so if
it is present, we can use that. This patch implements this behaviour.

Fixes https://bugs.llvm.org/show_bug.cgi?id=45089.

Reviewed by: grimar, MaskRay

Differential Revision: https://reviews.llvm.org/D76352
2020-03-23 12:21:20 +00:00