This is a continuation of the YAML library error reporting
refactoring/improvement and the idea by itself was mentioned
in the following thread:
https://reviews.llvm.org/D67182?id=218714#inline-603404
This performs a cleanup of all object emitters in the library.
It allows using the custom one provided by the caller.
One of the nice things is that each tool can now print its tool name,
e.g: "yaml2obj: error: <text>"
Also, the code became a bit simpler.
Differential revision: https://reviews.llvm.org/D67445
llvm-svn: 371865
The address difference between two sections in a PT_LOAD is a constant.
Consider a hypothetical case (pagesize can be very small, say, 4).
```
.text sh_addralign=4
.text.hot sh_addralign=16
```
If we set p_align to 4, the PT_LOAD will be loaded at an address which
is a multiple of 4. The address of .text.hot is guaranteed to be a
multiple of 4, but not necessarily a multiple of 16.
This patch deletes the constraint
if (SHeader->sh_offset == PHeader.p_offset)
Reviewed By: grimar, jhenderson
Differential Revision: https://reviews.llvm.org/D67260
llvm-svn: 371501
This fixes a bug as well. When "FileSize:" (p_filesz) is specified and
different from the actual value, the following code probably should not
use PHeader.p_filesz:
if (SHeader->sh_offset == PHeader.p_offset + PHeader.p_filesz)
PHeader.p_memsz += SHeader->sh_size;
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D67256
llvm-svn: 371420
The aim of this patch is to refactor how we handle and report error.
I suggest to use the same approach we use in LLD: delayed error reporting.
For that I introduced 'HasError' flag which triggers when we report an error.
Now we do not exit instantly on any error. The benefits are:
1) There are no more 'exit(1)' calls in the library code.
2) Code was simplified significantly in a few places.
3) It is now possible to print multiple errors instead of only one.
Also, I changed the messages to be lower case and removed a full stop.
Differential revision: https://reviews.llvm.org/D67182
llvm-svn: 371380
`struct Elf*_Shdr` has a field `sh_offset`, named `ShOffset` in
llvm::ELFYAML::Section. Rename SHOffset (e_shoff) to SHOff to prevent confusion.
Reviewed By: grimar
Differential Revision: https://reviews.llvm.org/D67254
llvm-svn: 371185
Summary: It says [[ http://www.sco.com/developers/gabi/latest/ch4.eheader.html | here ]] that if there are no program headers than e_phoff should be 0, but currently it is always set after the header. GNU's `readelf` (but not `llvm-readelf`) complains about this: `readelf: Warning: possibly corrupt ELF header - it has a non-zero program header offset, but no program headers`.
Reviewers: jhenderson, grimar, MaskRay, rupprecht
Reviewed By: jhenderson, grimar, MaskRay
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D67054
llvm-svn: 371162
Linkers (ld.bfd/gold/lld) place the section header table at the very
end. This allows tools to strip it, which is optional in executable/shared objects.
In addition, if we add or section, the size of the section header table
will change. Placing the section header table in the end keeps section
offsets unchanged.
yaml2obj currently places the section header table immediately after the
program header. Follow what linkers do to make offset updating easier.
Reviewed By: grimar
Differential Revision: https://reviews.llvm.org/D67221
llvm-svn: 371074
In D62809 I accidentally added "ELFState<ELFT> &State" as the
first parameter to two methods. There is no reason for having that.
I removed this argument and also moved finalizeStrings declaration to
remove an excessive 'private:' tag.
Differential revision: https://reviews.llvm.org/D67157
llvm-svn: 371033
This is in line with the previous changes which allowed to
override the sh_offset/sh_size and useful for writing test cases.
Differential revision: https://reviews.llvm.org/D66998
llvm-svn: 370633
Currenly we can encode the 'st_other' field of symbol using 3 fields.
'Visibility' is used to encode STV_* values.
'Other' is used to encode everything except the visibility, but it can't handle arbitrary values.
'StOther' is used to encode arbitrary values when 'Visibility'/'Other' are not helpfull enough.
'st_other' field is used to encode symbol visibility and platform-dependent
flags and values. Problem to encode it is that it consists of Visibility part (STV_* values)
which are enumeration values and the Other part, which is different and inconsistent.
For MIPS the Other part contains flags for all STO_MIPS_* values except STO_MIPS_MIPS16.
(Like comment in ELFDumper says: "Someones in their infinite wisdom decided to make
STO_MIPS_MIPS16 flag overlapped with other ST_MIPS_xxx flags."...)
And for PPC64 the Other part might actually encode any value.
This patch implements custom logic for handling the st_other and removes
'Visibility' and 'StOther' fields.
Here is an example of a new YAML style this patch allows:
- Name: foo
Other: [ 0x4 ]
- Name: bar
Other: [ STV_PROTECTED, 4 ]
- Name: zed
Other: [ STV_PROTECTED, STO_MIPS_OPTIONAL, 0xf8 ]
Differential revision: https://reviews.llvm.org/D66886
llvm-svn: 370472
This allows us to produce broken binaries with local
symbols placed after global in '.dynsym'/'.symtab'
Also, simplifies the code.
Differential revision: https://reviews.llvm.org/D66799
llvm-svn: 370331
This relands this commit, I mistakenly reverted the original change
thinking it was the cause of the observed MSan failures but it was not.
llvm-svn: 370206
This is a follow up discussed in the comments of D66583.
Currently, if for example, we have both StOther and Other set in YAML document for a symbol,
then yaml2obj reports an "unknown key 'Other'" error.
It happens because 'mapOptional()' is never called for 'Other/Visibility' in this case,
leaving those unhandled.
This message does not describe the reason of the error well. This patch fixes it.
Differential revision: https://reviews.llvm.org/D66642
llvm-svn: 370032
This fixes https://bugs.llvm.org/show_bug.cgi?id=40337.
Previously, it was always assumed that relocations referenced symbols in the static symbol table.
Now, if the Link field references a section called ".dynsym" it will look up these symbols
in the dynamic symbol table.
This patch is heavily based on D59097 by James Henderson
Differential revision: https://reviews.llvm.org/D66532
llvm-svn: 369645
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.
llvm-svn: 369013
In some cases a symbol might have section index == SHN_XINDEX.
This is an escape value indicating that the actual section header index
is too large to fit in the containing field.
Then the SHT_SYMTAB_SHNDX section is used. It contains the 32bit values
that stores section indexes.
ELF gABI says that there can be multiple SHT_SYMTAB_SHNDX sections,
i.e. for example one for .symtab and one for .dynsym
(1) https://groups.google.com/forum/#!topic/generic-abi/-XJAV5d8PRg
(2) DT_SYMTAB_SHNDX: http://www.sco.com/developers/gabi/latest/ch5.dynamic.html
In this patch I am only supporting a single SHT_SYMTAB_SHNDX associated
with a .symtab. This is a more or less common case which is used a few tests I saw in LLVM.
I decided not to create the SHT_SYMTAB_SHNDX section as "implicit",
but implement is like a kind of regular section for now.
i.e. tools do not recreate this section or its content, like they do for
symbol table sections, for example. That should allow to write all kind of
possible broken test cases for our needs and keep the output closer to requested.
Differential revision: https://reviews.llvm.org/D65446
llvm-svn: 368272
George Rimar