YAML support allows us to better test the feature in the subsequent patches. The implementation is quite similar to the .stack_sizes section.
Reviewed By: jhenderson, grimar
Differential Revision: https://reviews.llvm.org/D88717
`Link` is not an optional field currently.
Because of this it is not convenient to write macros.
This makes it optional and fixes corresponding test cases.
Differential revision: https://reviews.llvm.org/D90390
Many sections either do not have a support of `Size`/`Content` or support just a
one of them, e.g only `Content`.
`Section` is the base class for sections. This patch adds `Content` and `Size` members
to it and removes similar members from derived classes. This allows to cleanup and
generalize the code and adds a support of these keys for all sections (`SHT_MIPS_ABIFLAGS`
is a only exception, it requires unrelated specific changes to be done).
I had to update/add many tests to test the new functionality properly.
Differential revision: https://reviews.llvm.org/D89039
The `Group` class represents a group section and it is
named inconsistently with other sections which all has
the "Section" suffix. It is sometimes confusing,
this patch addresses the issue.
Differential revision: https://reviews.llvm.org/D88892
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.
Currently both GNU linkers and LLD sets the `sh_entsize` field to `4`.
At the same time, `yaml2obj` ignores the `EntSize` field for SHT_HASH sections.
This patch fixes this and also adds a support for obj2yaml: it will not
dump this field when the `sh_entsize` contains the default value (`4`).
Differential revision: https://reviews.llvm.org/D88652
Currently we are always recognizing the `SHT_MIPS_ABIFLAGS` section,
even on non-MIPS targets.
The problem of doing this is briefly discussed in D88228 which does the same for `SHT_ARM_EXIDX`:
"The problem is that `SHT_ARM_EXIDX` shares the value with `SHT_X86_64_UNWIND (0x70000001U)`.
We might have other machine specific conflicts, e.g.
`SHT_ARM_ATTRIBUTES` vs `SHT_MSP430_ATTRIBUTES` vs `SHT_RISCV_ATTRIBUTES (0x70000003U)`."
I think we should only recognize target specific sections when the machine type
matches. I.e. `SHT_MIPS_*` should be recognized only on `MIPS`, `SHT_ARM_*`
only on `ARM` etc.
This patch stops recognizing `SHT_MIPS_ABIFLAGS` on `non-MIPS` targets.
Note: I had to update `ScalarEnumerationTraits<ELFYAML::MIPS_ISA>::enumeration`, because
otherwise test crashes, calling `llvm_unreachable`.
Differential revision: https://reviews.llvm.org/D88294
When ELF header's `e_machine == 0`, we emit:
```
Machine: EM_NONE
```
We can avoid doing this, because yaml2obj sets the
`e_machine` field to `EM_NONE` by default.
Differential revision: https://reviews.llvm.org/D87829
Without this patch, obj2yaml decodes the content of only one ".stack_size" section. Other sections are dumped with their full contents.
Reviewed By: grimar, MaskRay
Differential Revision: https://reviews.llvm.org/D87727
Without this patch, obj2yaml decodes the content of only one ".stack_size" section. Other sections are dumped with their full contents.
Reviewed By: grimar, MaskRay
Differential Revision: https://reviews.llvm.org/D87727
This patch adds support for dumping the .debug_addr(v5) section to
obj2yaml.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D87601
`ELFFile<ELFT>` has many methods that take pointers,
though they assume that arguments are never null and
hence could take references instead.
This patch performs such clean-up.
Differential revision: https://reviews.llvm.org/D87385
This patch adds support for dumping the .debug_ranges section to
elf2yaml.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D87429
If the debug section's name isn't recognized, it should be
dumped as a raw content section.
Reviewed By: jhenderson, grimar
Differential Revision: https://reviews.llvm.org/D87346
This removes Error.cpp/.h files from obj2yaml.
These files are not needed because we are
using `Error`s instead of error codes widely and do
not need a logic related to obj2yaml specific
error codes anymore.
I had to adjust just a few lines of tool's code
to remove remaining dependencies.
Differential revision: https://reviews.llvm.org/D86536
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
This patch adds support for dumping DWARF sections to obj2yaml. The
.debug_aranges section is used to illustrate the basic idea.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D85094
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 adds `EPhOff`, `EPhEntSize` and `EPhNum` keys.
Will be useful for creating broken objects for testing llvm-readelf.
Differential revision: https://reviews.llvm.org/D83482
For describing section/symbol names we can use unique suffixes,
e.g:
```
- Name: '.foo [1]`
- Name: '.foo [2]`
```
It can be a problem (see https://reviews.llvm.org/D79984#inline-734829),
because `[]` are sometimes used to describe a macros:
```
- Name: "[[a0]]"
```
Seems the better approach is to use something else, like "()".
This patch does it and refactors the code related.
Differential revision: https://reviews.llvm.org/D80123
SHT_NOBITS are a bit special because occupy no physical space.
This patch adds support for them.
Differential revision: https://reviews.llvm.org/D77805
This is a NFC splitted from D75342.
Previously obj2yaml never dumped a normal SHT_NULL section (i.e. when it is just zeroed)
or non-allocatable SHT_STRTAB/SHT_SYMTAB/SHT_DYNSYM sections.
This patch does not change the output, but it changes the logic so that we now dump these
sections, and them remove them later. It allows us to create and work with our internal representation
of sections, i.e. to work with the vector of Chunks, what looks cleaner.
It is used by D75342 and also should help us to support dumping a content that does not
belong to a section (i.e. to dump some data as `Fill` chunks).
Differential revision: https://reviews.llvm.org/D76684
This method it a bit too large.
It is becoming inconvenient to update it.
This patch suggests a way to reduce and cleanup it.
Differential revision: https://reviews.llvm.org/D76499
Currently obj2yaml always emits the `EntSize` property when `sh_entsize != 0`.
It is not correct. For example, for `SHT_DYNAMIC` section, `EntSize == 0`
is abnormal, while `sizeof(ELFT::Dyn)` is the expected default.
To reduce the output produces we should not dump default values.
yaml2obj tests that shows `sh_entsize` values produced are:
1) For `SHT_REL*` sections: `yaml2obj\ELF\reloc-sec-entry-size.yaml`
2) For `SHT_DYNAMIC`: `yaml2obj\ELF\dynamic-section.yaml`
Differential revision: https://reviews.llvm.org/D76227
`.rela.dyn` is a dynamic relocation section that normally has
no value in `sh_info` field.
The existent `elf-reladyn-section-shinfo.yaml` which tests this piece has issues:
1) It does not check the case when we have more than one `SHT_REL[A]`
section with `sh_info == 0` in the object. Because of this it did not catch the issue.
Currently we print an excessive "Info" field:
```
- Name: .rela.dyn
Type: SHT_RELA
EntSize: 0x0000000000000018
- Name: .rel.dyn
Type: SHT_REL
EntSize: 0x0000000000000010
Info: ' [1]'
```
2) It seems can be more generic. I've added a `rel-rela-section.yaml` instead.
Differential revision: https://reviews.llvm.org/D76281
Sometimes we need to dump an object and build it again from a YAML
description produced. The problem is that obj2yaml does not dump some
of sections, like string tables and symbol tables.
Because of that yaml2obj implicitly creates them and sections created
are not placed at their original locations. They are added to the end of a section list.
That makes a preparing test cases task harder than it can be.
This patch teaches obj2yaml to dump parts of allocatable SHT_STRTAB, SHT_SYMTAB
and SHT_DYNSYM sections to print placeholders for them.
This also allows to preserve usefull parameters, like virtual address.
Differential revision: https://reviews.llvm.org/D74955
I've noticed that it is not convenient to create YAMLs from
binaries (using obj2yaml) that have to be test cases for obj2yaml
later (after applying yaml2obj).
The problem, for example is that obj2yaml emits "DynamicSymbols:"
key instead of .dynsym. It also does not create .dynstr.
And when a YAML document without explicitly defined .dynsym/.dynstr
is given to yaml2obj, we have issues:
1) These sections are placed after non-allocatable sections (I've fixed it in D74756).
2) They have VA == 0. User needs create descriptions for such sections explicitly manually
to set a VA.
This patch addresses (2). I suggest to let yaml2obj assign virtual addresses by itself.
It makes an output binary to be much closer to "normal" ELF.
(It is still possible to use "Address: 0x0" for a section to get the original behavior
if it is needed)
Differential revision: https://reviews.llvm.org/D74764
I was reported that with commit:
https://github.com/llvm/llvm-project/commit/d3963051c490
gcc-9.2 is giving the warning below.
This should help (I have no gcc 9.2 to test).
[ 57%] Building CXX object tools/obj2yaml/CMakeFiles/obj2yaml.dir/elf2yaml.cpp.o
/llvm/tools/obj2yaml/elf2yaml.cpp: In instantiation of ‘llvm::Expected<llvm::ELFYAML::Object*>
{anonymous}::ELFDumper<ELFT>::dump() [with ELFT = llvm::object::ELFType<llvm::support::little, false>]’:
/llvm/tools/obj2yaml/elf2yaml.cpp:1218:31: required from ‘llvm::Error elf2yaml(llvm::raw_ostream&,
const llvm::object::ELFFile<ELFT>&) [with ELFT = llvm::object::ELFType<llvm::support::little, false>]’
/llvm/tools/obj2yaml/elf2yaml.cpp:1231:47: required from here
/llvm/tools/obj2yaml/elf2yaml.cpp:207:41: warning: comparison of integer expressions of different
signedness: ‘llvm::support::detail::packed_endian_specific_integral<unsigned int, llvm::support::little, 1>::value_type’ {aka ‘unsigned int’} and ‘int’ [-Wsign-compare]
207 | if (!SymTab || SymTabShndx->sh_link != SymTab - Sections.begin())
/llvm/tools/obj2yaml/elf2yaml.cpp: In instantiation of ‘llvm::Expected<llvm::ELFYAML::Object*>
{anonymous}::ELFDumper<ELFT>::dump() [with ELFT = llvm::object::ELFType<llvm::support::big, false>]’:
...
Previously the description allowed to describe symbols with use of
`Name` and `Index` keys. This patch removes them and now it is still
possible to use either names or symbol indexes, but the code is simpler
and the format is slightly different.
Such a change will be useful for another patches, e.g:
https://reviews.llvm.org/D73788#inline-671077
Differential revision: https://reviews.llvm.org/D73888
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.
This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.
This doesn't actually modify StringRef yet, I'll do that in a follow-up.
Note: this is a reland with a trivial 2 lines fix in ELFState<ELFT>::writeSectionContent.
It adds a check similar to ones we already have for other sections to fix the case revealed
by bots, like http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-ubuntu-fast/builds/60744.
The encoded sequence of Elf*_Relr entries in a SHT_RELR section looks
like [ AAAAAAAA BBBBBBB1 BBBBBBB1 ... AAAAAAAA BBBBBB1 ... ]
i.e. start with an address, followed by any number of bitmaps. The address
entry encodes 1 relocation. The subsequent bitmap entries encode up to 63(31)
relocations each, at subsequent offsets following the last address entry.
More information is here:
https://github.com/llvm-mirror/llvm/blob/master/lib/Object/ELF.cpp#L272
This patch adds a support for these sections.
Differential revision: https://reviews.llvm.org/D71872
The encoded sequence of Elf*_Relr entries in a SHT_RELR section looks
like [ AAAAAAAA BBBBBBB1 BBBBBBB1 ... AAAAAAAA BBBBBB1 ... ]
i.e. start with an address, followed by any number of bitmaps. The address
entry encodes 1 relocation. The subsequent bitmap entries encode up to 63(31)
relocations each, at subsequent offsets following the last address entry.
More information is here:
https://github.com/llvm-mirror/llvm/blob/master/lib/Object/ELF.cpp#L272
This patch adds a support for these sections.
Differential revision: https://reviews.llvm.org/D71872
We already have Symbols property to list regular symbols and
it is currently Optional<>. This patch makes DynamicSymbols to be optional
too. With this there is no need to define a dummy symbol anymore to trigger
creation of the .dynsym and it is now possible to define an empty .dynsym using
just the following line:
DynamicSymbols: []
(it is important to have when you do not want to have dynamic symbols,
but want to have a .dynsym)
Now the code is consistent and it helped to fix a bug: previously we
did not report an error when both Content/Size and an empty
Symbols/DynamicSymbols list were specified.
Differential revision: https://reviews.llvm.org/D70956
This section contains strings specifying libraries to be added to the link by the linker.
The strings are encoded as standard null-terminated UTF-8 strings.
This patch adds a way to describe and dump SHT_LLVM_DEPENDENT_LIBRARIES sections.
I introduced a new YAMLFlowString type here. That used to teach obj2yaml to dump
them like:
```
Libraries: [ foo, bar ]
```
instead of the following (if StringRef would be used):
```
Libraries:
- foo
- bar
```
Differential revision: https://reviews.llvm.org/D70598
SHT_LLVM_LINKER_OPTIONS section contains pairs of null-terminated strings.
This patch adds support for them.
Differential revision: https://reviews.llvm.org/D69895
Currently there is no way to describe the data that is not a part of an output section.
It can be a data used to align sections or to fill the gaps with something,
or another kind of custom data. In this patch I suggest a way to describe it. It looks like that:
```
Sections:
- Type: CustomFiller
Pattern: "CCDD"
Size: 4
- Name: .bar
Type: SHT_PROGBITS
Content: "FF"
```
I.e. I've added a kind of synthetic section with a synthetic type "CustomFiller".
In the code it is called a "SyntheticFiller", which is "a synthetic section which
might be used to write the custom data around regular output sections. It does
not present in the sections header table, but it might affect the output file size and
program headers produced. Think about it as about piece of data."
`SyntheticFiller` currently has a `Pattern` field and a `Size` field + an optional `Name`.
When written, `Size` of bytes in the output will be filled with a `Pattern`.
It is possible to reference a named filler it by name from the program headers description,
just like any other normal section.
Differential revision: https://reviews.llvm.org/D69709
