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
Don't quote octal compatible strings if they are only two wide, they
aren't ambiguous.
This reverts commit r205857 which reverted r205857.
llvm-svn: 205914
obj2yaml would fail when seeing a Weak External auxiliary record with a
characteristics field holding zero instead of one of
IMAGE_WEAK_EXTERN_SEARCH_NOLIBRARY, IMAGE_WEAK_EXTERN_SEARCH_NOLIBRARY,
or IMAGE_WEAK_EXTERN_SEARCH_NOLIBRARY.
llvm-svn: 205911
YAMLIO would turn a BinaryRef into the string 0000000004000000.
However, the leading zero causes parsers to interpret it as being an
octal number instead of a hexadecimal one.
Instead, escape such strings as needed.
llvm-svn: 205839
The IO normalizer would essentially lump I386 and AMD64 relocations
together. Relocation types with the same numeric value would then get
mapped in appropriately.
For example:
IMAGE_REL_AMD64_ADDR64 and IMAGE_REL_I386_DIR16 both have a numeric
value of one. We would see IMAGE_REL_I386_DIR16 in obj2yaml conversions
of object files with a machine type of IMAGE_FILE_MACHINE_AMD64.
llvm-svn: 205746
This reverts commit r205479.
It turns out that nm does use addresses, it is just that every reasonable
relocatable ELF object has sections with address 0. I have no idea if those
exist in reality, but it at least it shows that llvm-nm should use the name
address.
The added test was includes an unusual .o file with non 0 section addresses. I
created it by hacking ELFObjectWriter.cpp.
Really sorry for the churn.
llvm-svn: 205493
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
The current state of affairs has auxiliary symbols described as a big
bag of bytes. This is less than satisfying, it detracts from the YAML
file as being human readable.
Instead, allow for symbols to optionally contain their auxiliary data.
This allows us to have a much higher level way of describing things like
weak symbols, function definitions and section definitions.
This depends on D3105.
Differential Revision: http://llvm-reviews.chandlerc.com/D3092
llvm-svn: 204214
This interface allows IRObjectFile to be implemented without having dummy
methods for all section and segment related methods.
Both llvm-ar and llvm-nm are changed to use it. Unfortunately the mangler is
still not plugged in since it requires some refactoring to make a Module hold
a DataLayout.
llvm-svn: 201881
COFF has only one symbol table.
MachO has a LC_DYSYMTAB, but that is not a symbol table, just extra info about
the one symbol table (LC_SYMTAB).
IR (coming soon) also has only one table.
llvm-svn: 200488
This fixes a regression introduced by r182908, which broke
llvm-objdump's ability to display relocations inline in a disassembly
dump for ELF object files.
That change removed a SectionRelocMap from Object/ELF.h, which we
recreate in llvm-objdump.cpp.
I discovered this regression via an out-of-tree test
(test/NaCl/X86/pnacl-hides-sandbox-x86-64.ll) which used llvm-objdump.
Note that the "Unknown" string in the test output on i386 isn't quite
right, but this appears to be a pre-existing bug.
Differential Revision: http://llvm-reviews.chandlerc.com/D2559
llvm-svn: 200090
Linux cannot open directories with open(2), although cygwin and *bsd can.
Motivation: The test, Object/directory.ll, had been failing with --target=cygwin on Linux. XFAIL was improper for host issues.
llvm-svn: 194257
This is just enough to get "llvm-ranlib foo.a" working and tested. Making
llvm-ranlib a symbolic link to llvm-ar doesn't work so well with llvm's option
parsing, but ar's option parsing is mostly custom anyway.
This patch also removes the -X32_64 option. Looks like it was just added in
r10297 as part of implementing the current command line parsing. I can add it
back (with a test) if someone really has AIX portability problems without it.
llvm-svn: 189489
- Instead of setting the suffixes in a bunch of places, just set one master
list in the top-level config. We now only modify the suffix list in a few
suites that have one particular unique suffix (.ml, .mc, .yaml, .td, .py).
- Aside from removing the need for a bunch of lit.local.cfg files, this enables
4 tests that were inadvertently being skipped (one in
Transforms/BranchFolding, a .s file each in DebugInfo/AArch64 and
CodeGen/PowerPC, and one in CodeGen/SI which is now failing and has been
XFAILED).
- This commit also fixes a bunch of config files to use config.root instead of
older copy-pasted code.
llvm-svn: 188513
* 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
If no other operation is specified, 's' becomes an operation instead of an
modifier. The s operation just creates a symbol table. It is the same as
running ranlib.
We assume the archive was created by a sane ar (like llvm-ar or gnu ar) and
if the symbol table is present, then it is current. We use that to optimize
the most common case: a broken build system that thinks it has to run ranlib.
llvm-svn: 187353
The symbol table has forward references in the file. Instead of allocating
a temporary buffer or counting the size and then writing, this implementation
writes a dummy value first and patches it once the final value is known.
There is room for performance improvement. I will implement them as soon as I
get some other features (like a ranlib mode) in.
llvm-svn: 186934
This matches gnu archive behavior and since archive member order can change
which member is used, not changing the order on replacement looks like the
right thing to do.
This patch also refactors the logic for which archive member to keep and
whether to move it to a helper function (computeInsertAction). The
nesting in computeNewArchiveMembers was getting a bit confusing.
llvm-svn: 186829
GNU ar when not given the a or b modifiers replaces archive members in the
same location of the old ones. I am about to implement that in llvm-ar. For
now, just don't depend on the current llvm-ar behavior on this test.
llvm-svn: 186823
This has some advantages:
* Lets us use native, utf16 windows functions.
* Easy to produce good errors on windows about trying to use a
directory when we want a file.
* Simplifies the unix version a bit.
llvm-svn: 186511
llvm-ar is the only user of toWin32Time() (via setLastModificationAndAccessTime), and r186298 can be reverted.
It had been buggy since the initial commit.
FIXME: Could we rename {from|to}Win32Time as {from|to}Win32FILETIME in TimeValue?
llvm-svn: 186374
Joerg Sonnenberger tells me one can open a directory in freebsd. I will try
to centralize our calls to open so that we can handle O_BINARY in one place,
and will then handle this there too.
llvm-svn: 186317
is executed within the same second as the inputs for the test are
checked out from the source tree, it will fail to update due to being
below the resolution of the 'mtime' test used.
Now, this may seem improbably to you... ok, maybe *really* improbable,
but consider a system which does distributed execution of tests by
shipping their inputs to another machine and runs them. That might cause
the mtime to be quite recent during the test run. ;]
Instead, create two files directly in the test (allowing all platforms
to see the problem) and add either a use of the 'touch' command that
forces one mtime to some time quite a bit in the past, or it sleeps for
just over a second to be outside of the precision window.
llvm-svn: 186282
This fixes two bugs is lib/Object that the use in llvm-ar found:
* In OS X created archives, the name can be padded with nulls. Strip them.
* In the constructor, remember the first non special member and use that in
begin_children. This makes sure we skip all special members, not just the
first one.
The change to llvm-ar itself consist of
* Using lib/Object for reading archives instead of ArchiveReader.cpp.
* Writing the modified archive directly, instead of creating an in memory
representation.
The old Archive library was way more general than what is needed, as can
be seen by the diffstat of this patch.
Having llvm-ar using lib/Object now opens the way for creating regular symbol
tables for both native objects and bitcode files so that we can use those
archives for LTO.
llvm-svn: 186197
It is not reliable to depend on the output of llvm_unreachable. The original
change will have proper tests when llvm-ar moves to lib/Object (soon).
llvm-svn: 186043
There is no lib/Archive anymore and some archive tests were in test/Archive and
others in test/Object. Since archive is just one of the formats supported by
lib/Object, test/Object is probably the best location.
llvm-svn: 186038
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
It wouldn't really test anything that doesn't already have a more
targeted test:
`yaml2obj-elf-section-basic.yaml`:
Already tests that section content is correctly passed though.
`yaml2obj-elf-symbol-basic.yaml` (this file):
Tests that the st_value and st_size attributes of `main` are set
correctly.
Between those two tests, disassembling the file doesn't really add
anything, so just remove mention of disassembling the file.
llvm-svn: 184607
This reverts commit r184602. In an upcoming commit, I will just remove
the disassembler part of the test; it was mostly just a "nifty" thing
marking a milestone but it doesn't test anything that isn't tested
elsewhere.
llvm-svn: 184606
This was causing buildbot failures when build without X86 support.
Is there a way to conditionalize the test on the X86 target being
present?
llvm-svn: 184597
Previously we unconditionally enforced that section references in
symbols in the YAML had a name that was a section name present in the
object, and linked the references to that section. Now, permit empty
section names (already the default, if the `Section` key is not
provided) to indicate SHN_UNDEF.
llvm-svn: 184513
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
This test case was a "sanity check"/"breathing" test case at first, but
is really fragile, which impairs changes to yaml2obj.
`test/Object/yaml2obj-elf-bits-endian.test` is much more robust and
serves as an adequate sanity check.
llvm-svn: 183811
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
from the LC_DATA_IN_CODE load command. And when disassembling print
the data in code formatted for the kind of data it and not disassemble those
bytes.
I added the format specific functionality to the derived class MachOObjectFile
since these tables only appears in Mach-O object files. This is my first
attempt to modify the libObject stuff so if folks have better suggestions
how to fit this in or suggestions on the implementation please let me know.
rdar://11791371
llvm-svn: 183424
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
For COFF and MachO, sections semantically have relocations that apply to them.
That is not the case on ELF.
In relocatable objects (.o), a section with relocations in ELF has offsets to
another section where the relocations should be applied.
In dynamic objects and executables, relocations don't have an offset, they have
a virtual address. The section sh_info may or may not point to another section,
but that is not actually used for resolving the relocations.
This patch exposes that in the ObjectFile API. It has the following advantages:
* Most (all?) clients can handle this more efficiently. They will normally walk
all relocations, so doing an effort to iterate in a particular order doesn't
save time.
* llvm-readobj now prints relocations in the same way the native readelf does.
* probably most important, relocations that don't point to any section are now
visible. This is the case of relocations in the rela.dyn section. See the
updated relocation-executable.test for example.
llvm-svn: 182908
This is a basic first step towards symbolization of disassembled
instructions. This used to be done using externally provided (C API)
callbacks. This patch introduces:
- the MCSymbolizer class, that mimics the same functions that were used
in the X86 and ARM disassemblers to symbolize immediate operands and
to annotate loads based off PC (for things like c string literals).
- the MCExternalSymbolizer class, which implements the old C API.
- the MCRelocationInfo class, which provides a way for targets to
translate relocations (either object::RelocationRef, or disassembler
C API VariantKinds) to MCExprs.
- the MCObjectSymbolizer class, which does symbolization using what it
finds in an object::ObjectFile. This makes simple symbolization (with
no fancy relocation stuff) work for all object formats!
- x86-64 Mach-O and ELF MCRelocationInfos.
- A basic ARM Mach-O MCRelocationInfo, that provides just enough to
support the C API VariantKinds.
Most of what works in otool (the only user of the old symbolization API
that I know of) for x86-64 symbolic disassembly (-tvV) works, namely:
- symbol references: call _foo; jmp 15 <_foo+50>
- relocations: call _foo-_bar; call _foo-4
- __cf?string: leaq 193(%rip), %rax ## literal pool for "hello"
Stub support is the main missing part (because libObject doesn't know,
among other things, about mach-o indirect symbols).
As for the MCSymbolizer API, instead of relying on the disassemblers
to call the tryAdding* methods, maybe this could be done automagically
using InstrInfo? For instance, even though PC-relative LEAs are used
to get the address of string literals in a typical Mach-O file, a MOV
would be used in an ELF file. And right now, the explicit symbolization
only recognizes PC-relative LEAs. InstrInfo should have already have
most of what is needed to know what to symbolize, so this can
definitely be improved.
I'd also like to remove object::RelocationRef::getValueString (it seems
only used by relocation printing in objdump), as simply printing the
created MCExpr is definitely enough (and cleaner than string concats).
llvm-svn: 182625
There were two problems that made llvm-objdump -r crash:
- for non-scattered relocations, the symbol/section index is actually in the
(aptly named) symbolnum field.
- sections are 1-indexed.
llvm-svn: 181843
The alignment is just a byte in the middle of Characteristics, not an
independent flag. Making it an independent field in the yaml
representation makes it more yamlio friendly.
llvm-svn: 181243
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
Thanks to Evgeniy Stepanov for reporting this.
It might be a good idea to add a command iterator abstraction to MachO.h, but
this fixes the bug for now.
llvm-svn: 179848
It had been dropped during the switch to yaml::IO. Also add a test going
from yaml2obj to llvm-readobj. It can be extended as we add more
fields/formats to yaml2obj.
llvm-svn: 178786
Normally r_info is just a 32 of 64 bit number matching the endian of the rest
of the file. Unfortunately, mips 64 bit little endian is special: The top 32
bits are a little endian number and the following 32 are a big endian one.
llvm-svn: 178694
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
Simon Atanasyan