field represents ELF section header sh_info field and does not have any
sense for regular sections. Its interpretation depends on section type.
llvm-svn: 209801
Some bit-set fields used in ELF file headers in fact contain two parts.
The first one is a regular bit-field. The second one is an enumeraion.
For example ELF header `e_flags` for MIPS target might contain the
following values:
Bit-set values:
EF_MIPS_NOREORDER = 0x00000001
EF_MIPS_PIC = 0x00000002
EF_MIPS_CPIC = 0x00000004
EF_MIPS_ABI2 = 0x00000020
Enumeration:
EF_MIPS_ARCH_32 = 0x50000000
EF_MIPS_ARCH_64 = 0x60000000
EF_MIPS_ARCH_32R2 = 0x70000000
EF_MIPS_ARCH_64R2 = 0x80000000
For printing bit-sets we use the `yaml::IO::bitSetCase()`. It does not
support bit-set/enumeration combinations and prints too many flags from
an enumeration part. This patch fixes this problem. New method
`yaml::IO::maskedBitSetCase()` handle "enumeration" part of bitset
defined by provided mask.
Patch reviewed by Nick Kledzik and Sean Silva.
llvm-svn: 209504
Now the only method to configure ELF section's content and size is to assign
a hexadecimal string to the `Content` field. Unfortunately this way is
completely useless when you need to declare a really large section.
To solve this problem this patch adds one more optional field `Size`
to the `RawContentSection` structure. When yaml2obj generates an ELF file
it uses the following algorithm:
1. If both `Content` and `Size` fields are missed create an empty section.
2. If only `Content` field is missed take section length from the `Size`
field and fill the section by zero.
3. If only `Size` field is missed create a section using data from
the `Content` field.
4. If both `Content` and `Size` fields are provided validate that the `Size`
value is not less than size of `Content` data. Than take section length
from the `Size`, fill beginning of the section by `Content` and the rest
by zero.
Examples
--------
* Create a section 0x10000 bytes long filled by zero
Name: .data
Type: SHT_PROGBITS
Flags: [ SHF_ALLOC ]
Size: 0x10000
* Create a section 0x10000 bytes long starting from 'CA' 'FE' 'BA' 'BE'
Name: .data
Type: SHT_PROGBITS
Flags: [ SHF_ALLOC ]
Content: CAFEBABE
Size: 0x10000
The patch reviewed by Michael Spencer.
llvm-svn: 208995
The ELF header e_flags field in the MIPS related test cases handled
incorrectly. The obj2yaml prints too many flags. I will fix that in the
next patches.
The patch reviewed by Michael Spencer and Sean Silva.
llvm-svn: 208752
which are corresponding to the current target read from the ELF file.
This fix cannot be tested until obj2yaml does not support ELF format.
llvm-svn: 207905
The patch implements support for both relocation record formats: Elf_Rel
and Elf_Rela. It is possible to define relocation against symbol only.
Relocations against sections will be implemented later. Now yaml2obj
recognizes X86_64, MIPS and Hexagon relocation types.
Example of relocation section specification:
Sections:
- Name: .text
Type: SHT_PROGBITS
Content: "0000000000000000"
AddressAlign: 16
Flags: [SHF_ALLOC]
- Name: .rel.text
Type: SHT_REL
Info: .text
AddressAlign: 4
Relocations:
- Offset: 0x1
Symbol: glob1
Type: R_MIPS_32
- Offset: 0x2
Symbol: glob2
Type: R_MIPS_CALL16
The patch reviewed by Michael Spencer, Sean Silva, Shankar Easwaran.
llvm-svn: 206017
Summary:
The FileHeader mapping now accepts an optional Flags sequence that accepts
the EF_<arch>_<flag> constants. When not given, Flags defaults to zero.
Reviewers: atanasyan
Reviewed By: atanasyan
CC: llvm-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D3213
llvm-svn: 205173
Although in reality the symbol table in ELF resides in a section, the
standard requires that there be no more than one SHT_SYMTAB. To enforce
this constraint, it is cleaner to group all the symbols under a
top-level `Symbols` key on the object file.
llvm-svn: 184627
Instead, just have 3 sub-lists, one for each of
{STB_LOCAL,STB_GLOBAL,STB_WEAK}.
This allows us to be a lot more explicit w.r.t. the symbol ordering in
the object file, because if we allowed explicitly setting the STB_*
`Binding` key for the symbol, then we might have ended up having to
shuffle STB_LOCAL symbols to the front of the list, which is likely to
cause confusion and potential for error.
Also, this new approach is simpler ;)
llvm-svn: 184506
After this patch, the ELF file produced by
`yaml2obj-elf-symbol-basic.yaml`, when linked and executed on x86_64
(under SysV ABI, obviously; I tested on Linux), produces a working
executable that goes into an infinite loop!
llvm-svn: 184469
For consistency, change the address in the test case from 0xDEADBEEF to
0xCAFEBABE since 0xCAFEBABE that actually has a 2-byte alignment.
llvm-svn: 183962
Currently, only emitting the ELF header is supported (no sections or
segments).
The ELFYAML code organization is broadly similar to the COFFYAML code.
llvm-svn: 183711
Simon Atanasyan