We can probably do better in this method, but this is an improvement and
enables further ErrorOr cleanups.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241114 91177308-0d34-0410-b5e6-96231b3b80d8
If you only need Name and Value fields in the COFF symbol,
you don't need to distinguish 32 bit and 64 bit COFF symbols.
These fields start at the same offsets and have the same size.
This data strucutre is one pointer smaller than COFFSymbolRef
thus slightly efficient. I'll use this class in LLD as we create
millions of LLD symbol objects that currently contain COFFSymbolRef.
Shaving off 8 byte (or 4 byte on 32 bit) from that class actually
matters becasue of the number of objects we create in LLD.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241024 91177308-0d34-0410-b5e6-96231b3b80d8
This is still a really odd function. Most calls are in object format specific
contexts and should probably be replaced with a more direct query, but at least
now this is not too obnoxious to use.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240777 91177308-0d34-0410-b5e6-96231b3b80d8
On ELF that was already the case since getting the size of a symbol
never fails.
On MachO and COFF we could fail trying to get the section of a symbol. But
we don't really need the section, just the section number to know if two
symbols are in the same section or not.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240580 91177308-0d34-0410-b5e6-96231b3b80d8
This returns either the symbol offset or address. Since it is not defined which
one, it never has to lookup the section and so never fails.
I will add users in the next commit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240569 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240529 91177308-0d34-0410-b5e6-96231b3b80d8
There are 3 types of relocations on MachO
* Scattered
* Section based
* Symbol based
On ELF and COFF relocations are symbol based.
We were in the strange situation that we abstracted over two of them. This makes
section based relocations MachO only.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240149 91177308-0d34-0410-b5e6-96231b3b80d8
make_error_code(object_error) is slow because object::object_category()
uses a ManagedStatic variable. But the real problem is that the function is
called too frequently. This patch uses std::error_code() instead of
object_error::success. In most cases, we return "success", so this patch
reduces number of function calls to that function.
http://reviews.llvm.org/D10333
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239409 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This supersedes http://reviews.llvm.org/D4010, hopefully properly
dealing with the JIT case and also adds an actual test case.
DwarfContext was basically already usable for the JIT (and back when
we were overwriting ELF files it actually worked out of the box by
accident), but in order to resolve relocations correctly it needs
to know the load address of the section.
Rather than trying to get this out of the ObjectFile or requiring
the user to create a new ObjectFile just to get some debug info,
this adds the capability to pass in that info directly.
As part of this I separated out part of the LoadedObjectInfo struct
from RuntimeDyld, since it is now required at a higher layer.
Reviewers: lhames, echristo
Reviewed By: echristo
Subscribers: vtjnash, friss, rafael, llvm-commits
Differential Revision: http://reviews.llvm.org/D6961
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237961 91177308-0d34-0410-b5e6-96231b3b80d8
Add in definedness checks for shift operators, null checks when
pointers are assumed by the code to be non-null, and explicit
unreachables.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224255 91177308-0d34-0410-b5e6-96231b3b80d8
These methods are only used by MCJIT and are very specific to it. In fact, they
are also fairly specific to the fact that we have a dynamic linker of
relocatable objects.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223964 91177308-0d34-0410-b5e6-96231b3b80d8
We were a little lax in a few areas:
- We pretended that import libraries were like any old COFF file, they
are not. In fact, they aren't really COFF files at all, we should
probably grow some specialized functionality to handle them smarter.
- Our symbol iterators were more than happy to attempt to go past the
end of the symbol table if you had a symbol with a bad list of
auxiliary symbols.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222124 91177308-0d34-0410-b5e6-96231b3b80d8
In support of serializing executables, obj2yaml now records the virtual address
and size of sections. It also serializes whatever we strictly need from
the PE header, it expects that it can reconstitute everything else via
inference.
yaml2obj can reconstitute a fully linked executable.
In order to get executables correctly serialized/deserialized, other
bugs were fixed as a circumstance. We now properly respect file and
section alignments. We also avoid writing out string tables unless they
are strictly necessary.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221975 91177308-0d34-0410-b5e6-96231b3b80d8
Referencing one symbol from another in the same section does not
generally require a relocation. However, the MS linker has a feature
called /INCREMENTAL which enables incremental links. It achieves this
by creating thunks to the actual function and redirecting all
relocations to point to the thunk.
This breaks down with the old scheme if you have a function which
references, say, itself. On x86_64, we would use %rip relative
addressing to reference the start of the function from out current
position. This would lead to miscompiles because other references might
reference the thunk instead, breaking function pointer equality.
This fixes PR21520.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221678 91177308-0d34-0410-b5e6-96231b3b80d8
Do a better job classifying symbols. This increases the consistency
between the COFF handling code and the ELF side of things.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220952 91177308-0d34-0410-b5e6-96231b3b80d8
We, I suppose naïvely, believed the COFF specification with regard to
auxiliary symbol records which defined sections: they specified that the
symbol value should be zero. However, dumpbin and MinGW's objdump do
not consider the symbol value as a restriction. Relaxing this allows us
to properly dump MinGW linked executables.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219479 91177308-0d34-0410-b5e6-96231b3b80d8
While getSectionContents was updated to do the right thing,
getSectionSize wasn't. Move the logic to getSectionSize and leverage it
from getSectionContents.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219391 91177308-0d34-0410-b5e6-96231b3b80d8
There are two methods in SectionRef that can fail:
* getName: The index into the string table can be invalid.
* getContents: The section might point to invalid contents.
Every other method will always succeed and returning and std::error_code just
complicates the code. For example, a section can have an invalid alignment,
but if we are able to get to the section structure at all and create a
SectionRef, we will always be able to read that invalid alignment.
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This patch defines a new iterator for the imported symbols.
Make a change to COFFDumper to use that iterator to print
out imported symbols and its ordinals.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218915 91177308-0d34-0410-b5e6-96231b3b80d8
When the flag is given, the command prints out the COFF import table.
Currently only the import table directory will be printed.
I'm going to make another patch to print out the imported symbols.
The implementation of import directory entry iterator in
COFFObjectFile.cpp was buggy. This patch fixes that too.
http://reviews.llvm.org/D5569
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Teach WinCOFFObjectWriter how to write -mbig-obj style object files;
these object files allow for more sections inside an object file.
Our support for BigObj is notably different from binutils and cl: we
implicitly upgrade object files to BigObj instead of asking the user to
compile the same file *again* but with another flag. This matches up
with how LLVM treats ELF variants.
This was tested by forcing LLVM to always emit BigObj files and running
the entire test suite. A specific test has also been added.
I've lowered the maximum number of sections in a normal COFF file,
VS "14" CTP 3 supports no more than 65279 sections. This is important
otherwise we might not switch to BigObj quickly enough, leaving us with
a COFF file that we couldn't link.
yaml2obj support is all that remains to implement.
Differential Revision: http://reviews.llvm.org/D5349
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This adds support for reading the "bigobj" variant of COFF produced by
cl's /bigobj and mingw's -mbig-obj.
The most significant difference that bigobj brings is more than 2**16
sections to COFF.
bigobj brings a few interesting differences with it:
- It doesn't have a Characteristics field in the file header.
- It doesn't have a SizeOfOptionalHeader field in the file header (it's
only used in executable files).
- Auxiliary symbol records have the same width as a symbol table entry.
Since symbol table entries are bigger, so are auxiliary symbol
records.
Write support will come soon.
Differential Revision: http://reviews.llvm.org/D5259
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217496 91177308-0d34-0410-b5e6-96231b3b80d8
Owning the buffer is somewhat inflexible. Some Binaries have sub Binaries
(like Archive) and we had to create dummy buffers just to handle that. It is
also a bad fit for IRObjectFile where the Module wants to own the buffer too.
Keeping this ownership would make supporting IR inside native objects
particularly painful.
This patch focuses in lib/Object. If something elsewhere used to own an Binary,
now it also owns a MemoryBuffer.
This patch introduces a few new types.
* MemoryBufferRef. This is just a pair of StringRefs for the data and name.
This is to MemoryBuffer as StringRef is to std::string.
* OwningBinary. A combination of Binary and a MemoryBuffer. This is needed
for convenience functions that take a filename and return both the
buffer and the Binary using that buffer.
The C api now uses OwningBinary to avoid any change in semantics. I will start
a new thread to see if we want to change it and how.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216002 91177308-0d34-0410-b5e6-96231b3b80d8
