Not every program needs this information.
In particular, it is necessary and sufficient for a static linker to scan the
section table.
llvm-svn: 242833
llvm-readobj exists for testing llvm. We can safely stop the program
the first time we know the input in corrupted.
This is in preparation for making it handle a few more broken files.
llvm-svn: 242656
This also improves the logic of what is an error:
* getSection(uint_32): only return an error if the index is out of bounds. The
index 0 corresponds to a perfectly valid entry.
* getSection(Elf_Sym): Returns null for symbols that normally don't have
sections and error for out of bound indexes.
In many places this just moves the report_fatal_error up the stack, but those
can then be fixed in smaller patches.
llvm-svn: 241156
This moves the error checking for string tables to getStringTable which returns
an ErrorOr<StringRef>.
This improves error checking, makes it uniform across all string tables and
makes it possible to check them once instead of once per name.
llvm-svn: 240950
It was a fairly broken concept for an ELF only class.
An ELF file can have two symbol tables, but they have exactly the same
format. There is no concept of a dynamic or a static symbol. Storing this
on the iterator also makes us do more work per symbol than necessary. To fetch
a name we would:
* Find if we had a static or a dynamic symbol.
* Look at the corresponding symbol table and find the string table section.
* Look at the string table section to fetch its contents.
* Compute the name as a substring of the string table.
All but the last step can be done per symbol table instead of per symbol. This
is a step in that direction.
llvm-svn: 240939
The parser provides a convenient interface for reading llvm stackmap v1 sections
in object files.
This patch also includes a new option for llvm-readobj, '-stackmap', which uses
the parser to pretty-print stackmap sections for debugging/testing purposes.
llvm-svn: 240860
Summary: This will be used by the R600 backend.
Reviewers: chandlerc, rafael
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D10389
llvm-svn: 240329
The underlaying issues is that this code can't really know if an OS specific or
processor specific section number should return true or false.
One option would be to assert or return an error, but that looks like over
engineering since extensions are not that common.
It seems better to have these be direct implementation of the ELF spec so that
they are natural for someone familiar with ELF reading the code.
Code that does have to handle OS/Architecture specific values can do it at
a higher level.
llvm-svn: 239618
The ELF spec is very clear:
-----------------------------------------------------------------------------
If the value is non-zero, it represents a string table index that gives the
symbol name. Otherwise, the symbol table entry has no name.
--------------------------------------------------------------------------
In particular, a st_name of 0 most certainly doesn't mean that the symbol has
the same name as the section.
llvm-svn: 238899
CloudABI is a POSIX-like runtime environment built around the concept of
capability-based security. More details:
https://github.com/NuxiNL/cloudlibc
CloudABI uses its own ELFOSABI number. This number has been allocated by
the maintainers of ELF a couple of days ago.
Reviewed by: echristo
llvm-svn: 231681
Revert "Correctly handle references to section symbols."
Revert "Allow forward references to section symbols."
Rui found a regression I am debugging.
llvm-svn: 220010
When processing assembly like
.long .text
we were creating a new undefined symbol .text. GAS on the other hand would
handle that as a reference to the .text section.
This patch implements that by creating the section symbols earlier so that
they are visible during asm parsing.
The patch also updates llvm-readobj to print the symbol number in the relocation
dump so that the test can differentiate between two sections with the same name.
llvm-svn: 219829
Users of getSectionContents shouldn't try to pass in BSS or virtual
sections. In all instances, this is a bug in the code calling this
routine.
N.B. Some COFF implementations (like CL) will mark their BSS sections as
taking space on disk. This would confuse COFFObjectFile into thinking
the section is larger than the file.
llvm-svn: 218549
We need .symtab_shndxr if and only if a symbol references a section with an
index >= 0xff00.
The old code was trying to figure out if the section was needed ahead of time,
making it a fairly dependent on the code actually writing the table. It was
also somewhat conservative and would create the section in cases where it was
not needed.
If I remember correctly, the old structure was there so that the sections were
created in the same order gas creates them. That was valuable when MC's support
for ELF was new and we tested with elf-dump.py.
This patch refactors the symbol table creation to another class and makes it
obvious that .symtab_shndxr is really only created when we are about to output
a reference to a section index >= 0xff00.
While here, also improve the tests to use macros. One file is one section
short of needing .symtab_shndxr, the second one has just the right number.
llvm-svn: 204769
This compiles with no changes to clang/lld/lldb with MSVC and includes
overloads to various functions which are used by those projects and llvm
which have OwningPtr's as parameters. This should allow out of tree
projects some time to move. There are also no changes to libs/Target,
which should help out of tree targets have time to move, if necessary.
llvm-svn: 203083
Enhance the ARM specific parsing support in llvm-readobj to support attributes.
This allows for simpler tests to validate encoding of the build attributes as
specified in the ARM ELF specification.
llvm-svn: 200450
This adds some preliminary support for decoding ARM EHABI unwinding information.
The major functionality that remains from complete support is bytecode
translation.
Each Unwind Index Table is printed out as a separate entity along with its
section index, name, offset, and entries.
Each entry lists the function address, and if possible, the name, of the
function to which it corresponds. The encoding model, personality routine or
index, and byte code is also listed.
llvm-svn: 198734
* ELFTypes.h contains template magic for defining types based on endianess, size, and alignment.
* ELFFile.h defines the ELFFile class which provides low level ELF specific access.
* ELFObjectFile.h contains ELFObjectFile which uses ELFFile to implement the ObjectFile interface.
llvm-svn: 188022
In ELF (as in MachO), not all relocations point to symbols. Represent this
properly by using a symbol_iterator instead of a SymbolRef. Update llvm-readobj
ELF's dumper to handle relocatios without symbols.
llvm-svn: 183284
Build attribute sections can now be read if they exist via ELFObjectFile, and
the llvm-readobj tool has been extended with an option to dump this information
if requested. Regression tests are also included which exercise these features.
Also update the docs with a fixed ARM ABI link and a new link to the Addenda
which provides the build attributes specification.
llvm-svn: 181009
getRelocationAddress is for dynamic libraries and executables,
getRelocationOffset for relocatable objects.
Mark the getRelocationAddress of COFF and MachO as not implemented yet. Add a
test of ELF's. llvm-readobj -r now prints the same values as readelf -r.
llvm-svn: 180259
This option expands shown relocations from single line to a dictionary
format:
Relocation {
Offset: 0x4
Type: R_386_32 (1)
Symbol: sym
Info: 0x0
}
llvm-svn: 179359
ELF with support for:
- File headers
- Section headers + data
- Relocations
- Symbols
- Unwind data (only COFF/Win64)
The output format follows a few rules:
- Values are almost always output one per line (as elf-dump/coff-dump already do). - Many values are translated to something readable (like enum names), with the raw value in parentheses.
- Hex numbers are output in uppercase, prefixed with "0x".
- Flags are sorted alphabetically.
- Lists and groups are always delimited.
Example output:
---------- snip ----------
Sections [
Section {
Index: 1
Name: .text (5)
Type: SHT_PROGBITS (0x1)
Flags [ (0x6)
SHF_ALLOC (0x2)
SHF_EXECINSTR (0x4)
]
Address: 0x0
Offset: 0x40
Size: 33
Link: 0
Info: 0
AddressAlignment: 16
EntrySize: 0
Relocations [
0x6 R_386_32 .rodata.str1.1 0x0
0xB R_386_PC32 puts 0x0
0x12 R_386_32 .rodata.str1.1 0x0
0x17 R_386_PC32 puts 0x0
]
SectionData (
0000: 83EC04C7 04240000 0000E8FC FFFFFFC7 |.....$..........|
0010: 04240600 0000E8FC FFFFFF31 C083C404 |.$.........1....|
0020: C3 |.|
)
}
]
---------- snip ----------
Relocations and symbols can be output standalone or together with the section header as displayed in the example.
This feature set supports all tests in test/MC/COFF and test/MC/ELF (and I suspect all additional tests using elf-dump), making elf-dump and coff-dump deprecated.
Patch by Nico Rieck!
llvm-svn: 178679
Rafael Espindola