COFF short import files are special kind of files that contains only
DLL-exported symbol names. That's different from object files because
it has no data except symbol names.
This change implements a SymbolicFile interface for the short import
files so that symbol names can be accessed through that interface.
llvm-ar is now able to read the file and create symbol table entries
for short import files.
llvm-svn: 246276
In tree they are only used by llvm-readobj, but it is also used by
https://github.com/mono/CppSharp.
While at it, add some missing error checking.
llvm-svn: 244320
lld might end up using a small part of this, but it will be in a much
refactored form. For now this unblocks avoiding the full section scan in the
ELFFile constructor.
This also has a (very small) error handling improvement.
llvm-svn: 244282
This makes llvm-nm consistent with binutils nm on executables and DLLs.
For a vanilla hello world executable, the address of main should include
the default image base of 0x400000.
llvm-svn: 243755
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
For now the Archive owns the buffers of the thin archive members.
This makes for a simple API, but all the buffers are destructed
only when the archive is destructed. This should be fine since we
close the files after mmap so we should not hit an open file
limit.
llvm-svn: 242215
They should probably be created on anything that is not windows or linux, but I will
test on freebsd before changing that.
With this it is possible to bootstrap with llvm-ar instead of ar+ranlib on OS X.
llvm-svn: 241849
It looks like ld64 requires it. With this we seem to be able to bootstrap using
llvm-ar+/usr/bin/true instead of ar+ranlib (currently on stage2).
llvm-svn: 241842
No support for the symbol table yet (but will hopefully add it today).
We always use the long filename format so that we can align the member,
which is an advantage of the BSD format.
llvm-svn: 241721
Use AddressAlign field's value to properly align sections content in the
yaml2obj tool. Before this change the yaml2obj ignored AddressAlign and
always aligned section on 16 bytes boundary.
llvm-svn: 241674
getSymbolValue now returns a value that in convenient for most callers:
* 0 for undefined
* symbol size for common symbols
* offset/address for symbols the rest
Code that needs something more specific can check getSymbolFlags.
llvm-svn: 241605
They are implemented like that in some object formats, but for the interface
provided by lib/Object, SF_Undefined and SF_Common are different things.
This matches the ELF and COFF implementation and fixes llvm-nm for MachO.
llvm-svn: 241587
When talking about the virtual address of sections the coff spec says:
... for simplicity, compilers should set this to zero. Otherwise, it is an
arbitrary value that is subtracted from offsets during relocation.
We don't currently subtract it, so check that it is zero.
If some producer does create such files, we can change getRelocationOffset
instead.
llvm-svn: 241447
SHT_NOBITS sections do not have content in an object file. Now the yaml2obj
tool does not accept `Content` field for such sections, and the obj2yaml
tool does not attempt to read the section content from a file.
Restore r241350 and r241352.
llvm-svn: 241377
r241350 broke lld tests.
r241352 depends on r241350.
Original messages:
"[ELFYAML] Fix handling SHT_NOBITS sections by obj2yaml/yaml2obj tools"
"[ELFYAML] Make the Size field for .bss section optional"
llvm-svn: 241354
SHT_NOBITS sections do not have content in an object file. Now yaml2obj
tool does not accept `Content` field for such sections, and obj2yaml
tool does not attempt to read the section content from a file.
llvm-svn: 241350
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
This case had been failing on testers that didn't have x86 support. Rather
than XFAIL it on testers without x86 support, I've just assembled it and used
the raw object as the test input.
llvm-svn: 240875
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
COFF and MachO only define symbol sizes for common symbols. Reflect that
in the class hierarchy by having a method for common symbols only in the base
and a general one in ELF.
This avoids the need of using a magic value for the size, which had a few
problems
* Most callers didn't check for it.
* The ones that did could not tell the magic value from a file actually having
that value.
llvm-svn: 240529
Only common symbol on MachO and COFF have a size.
For COFF we already had a custom format.
For MachO, there is no native objdump and we were printing it as ELF. Now
we only print the sizes for symbols that actually have them.
llvm-svn: 240422
This patch changes getRelocationAddend to use ErrorOr and considers it an error
to try to get the addend of a REL section.
If, for example, a x86_64 file has a REL section, that file is corrupted and
we should reject it.
Using ErrorOr is not ideal since we check the section type once per relocation
instead of once per section.
Checking once per section would involve getRelocationAddend just asserting and
callers checking the section before iterating over the relocations.
In any case, this is an improvement and includes a test.
llvm-svn: 240176
We cannot prepend __imp_ in the IR mangler because a function reference may
be emitted unmangled in a constant initializer. The linker is expected to
resolve such references to thunks. This is covered by the new test case.
Strictly speaking we ought to emit two undefined symbols, one with __imp_ and
one without, as we cannot know which symbol the final object file will refer
to. However, this would require rather intrusive changes to IRObjectFile,
and lld works fine without it for now.
This reimplements r239437, which was reverted in r239502.
Differential Revision: http://reviews.llvm.org/D10400
llvm-svn: 239560
This reverts commit r239437.
This broke clang-cl self-hosts. We'd end up calling the __imp_ symbol
directly instead of using it to do an indirect function call.
llvm-svn: 239502
llvm-lib is intended to be a lib.exe compatible utility that also
understands bitcode. The implementation lives in a library so that
lld can use it to implement /lib.
Differential Revision: http://reviews.llvm.org/D10297
llvm-svn: 239434
Report proper error code from MachOObjectFile constructor if we
can't parse another segment load command (we already return a proper
error if segment load command contents is suspicious).
llvm-svn: 239109
Summary:
Properly report the error in segment load commands from MachOObjectFile
constructor instead of crashing the program.
Adjust the test case accordingly.
Test Plan: regression test suite
Reviewers: rafael, filcab
Subscribers: llvm-commits
llvm-svn: 239081
Summary:
Currently all load commands are parsed in MachOObjectFile constructor.
If the next load command cannot be parsed, or if command size is too
small, properly report it through the error code and fail to construct
the object, instead of crashing the program.
Test Plan: regression test suite
Reviewers: rafael, filcab
Subscribers: llvm-commits
llvm-svn: 239080
Summary: Instead, properly report this error from MachOObjectFile constructor.
Test Plan: regression test suite
Reviewers: rafael
Subscribers: llvm-commits
llvm-svn: 239078
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
MachO and COFF quite reasonably only define the size for common symbols.
We used to try to figure out the "size" by computing the gap from one symbol to
the next.
This would not be correct in general, since a part of a section can belong to no
visible symbol (padding, private globals).
It was also really expensive, since we would walk every symbol to find the size
of one.
If a caller really wants this, it can sort all the symbols once and get all the
gaps ("size") in O(n log n) instead of O(n^2).
On MachO this also has the advantage of centralizing all the checks for an
invalid n_sect.
llvm-svn: 238028
Rui Ueyama