Commit Graph

14 Commits

Author SHA1 Message Date
Haowei Wu 803745b945 [llvm-elfabi] Emit ELF .dynsym, .dynamic sections
This change makes llvm-elfabi tool to emit .dynsym and .dynamic
sections.

Differential Revision: https://reviews.llvm.org/D89432
2020-11-24 00:17:04 -08:00
Haowei Wu cf43308718 [llvm-elfabi] Emit ELF header and string table sections
This change serves to create the initial framework for outputting ELF
files from llvm-elfabi.

Differential Revision: https://reviews.llvm.org/D61767
2020-11-23 12:18:58 -08:00
Haowei Wu ae736d2957 Revert "[llvm-elfabi] Emit ELF header and string table sections"
This reverts commit 53c5fdd59a.

Reason of revert: Some builders failed to build with ld.
2020-11-23 11:58:51 -08:00
Haowei Wu 53c5fdd59a [llvm-elfabi] Emit ELF header and string table sections
This change serves to create the initial framework for outputting ELF
files from llvm-elfabi.

Differential Revision: https://reviews.llvm.org/D61767
2020-11-23 11:31:57 -08:00
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 b236b4cb43 [yaml2obj] - Set a default value for `PAddr` property of a program header to a value of `VAddr`
`PAddr` corresponds to `p_paddr` of a program header, which is the segment's physical
address for systems in which physical addressing is relevant. `p_paddr` is often equal
to `p_vaddr`, which is the virtual address of a segment.

This patch changes the default for `PAddr` from 0 to a value of `VAddr`.

Differential revision: https://reviews.llvm.org/D76131
2020-03-14 17:44:57 +03:00
Fangrui Song 55c81d4282 [test] Use yaml2obj -o %t instead of > %t
To improve consistency and avoid unneeded shell feature (output
redirection).

While here, make other changes to improve consistency

--docnum 1 => --docnum=1
-docnum=x => --docnum=x
2020-01-21 17:20:18 -08:00
George Rimar d0921a4696 [Object/ELF.h] - Improve error reporting.
The errors coming from ELF.h are usually not very
useful because they are uninformative. This patch is a
first step to improve the situation.

I tested this patch with a run of check-llvm and found
that few messages are untested. In this patch, I did not
add more tests but marked all such cases with a "TODO" comment.

For all tested messages I extended the error text to
provide more details (see test cases changed).

Differential revision: https://reviews.llvm.org/D64014

llvm-svn: 365183
2019-07-05 11:28:49 +00:00
George Rimar 0e7ed91264 [yaml2obj][obj2yaml] - Add support for dumping/parsing .dynamic sections.
This teaches the tools to parse and dump
the .dynamic section and its dynamic tags.

Differential revision: https://reviews.llvm.org/D57691

llvm-svn: 353606
2019-02-09 11:34:28 +00:00
Armando Montanez 8367b0750f [elfabi] Add support for reading dynamic symbols from binaries
This patch adds initial support for reading dynamic symbols from ELF binaries. Currently, STT_NOTYPE, STT_OBJECT, STT_FUNC, and STT_TLS are explicitly supported. Other symbol types are mapped to ELFSymbolType::Unknown to improve signal/noise ratio.

Symbols must meet two criteria to be read into in an ELFStub:

 - The symbol's binding must be STB_GLOBAL or STB_WEAK.
 - The symbol's visibility must be STV_DEFAULT or STV_PROTECTED.

This filters out symbols that aren't of interest during compile-time linking against a shared object.

This change uses DT_HASH and DT_GNU_HASH to determine the size of .dynsym. Using hash tables to determine the number of symbols in .dynsym allows llvm-elfabi to work on binaries without relying on section headers.

Differential Revision: https://reviews.llvm.org/D56031

llvm-svn: 352121
2019-01-24 22:39:21 +00:00
Armando Montanez 56d18121e2 [elfabi] Add support for reading DT_NEEDED from binaries
This patch gives elfabi the ability to read DT_NEEDED entries from ELF binaries
to populate NeededLibs in TextAPI's ELFStub.

Differential Revision: https://reviews.llvm.org/D55852

llvm-svn: 351592
2019-01-18 20:56:03 +00:00
Armando Montanez fe7ab3c22e [elfabi] Add support for reading DT_SONAME from binaries
This change gives the llvm-elfabi tool the ability to read DT_SONAME from a binary ELF file into an ELFStub.

Added:

 - DynamicEntries struct for storing dynamic entries that are relevant to elfabi.
 - terminatedSubstr() retrieves a null-terminated substring from a StringRef.
 - appendToError() appends a string to an error, allowing more specific error messages.

Differential Revision: https://reviews.llvm.org/D55629

llvm-svn: 351361
2019-01-16 17:47:16 +00:00
Armando Montanez 488545ef15 [elfabi] Add option to manually specify file read format
Although llvm-elfabi will attempt to read input files without needing the format to be manually specified, doing so has the potential to introduce extraneous errors that can hinder debugging (since multiple readers may fail in attempts to read the file). This change allows the input file format to be manually specified to force elfabi to use a single reader. This makes it easier to test and debug errors specific to a given reader.

llvm-svn: 350545
2019-01-07 17:33:10 +00:00
Armando Montanez 31f0f659a8 [elfabi] Introduce tool for ELF TextAPI
Follow up for D53051

This patch introduces the tool associated with the ELF implementation of
TextAPI (previously llvm-tapi, renamed for better distinction). This
tool will house a number of features related to enalysis and
manipulation of shared object's exposed interfaces. The first major
feature for this tool is support for producing binary stubs that are
useful for compile-time linking of shared objects. This patch introduces
beginnings of support for reading binary ELF objects to work towards
that goal.

Added:

 - elfabi tool.
 - support for reading architecture from a binary ELF file into an
 ELFStub.
 - Support for writing .tbe files.

Differential Revision: https://reviews.llvm.org/D55352

llvm-svn: 350341
2019-01-03 18:32:36 +00:00