"Discarded" section is a marker for discarded sections, and we do not
use the instance except for checking its identity. In that sense, it
is just another type of a "null" pointer for InputSectionBase. So,
it doesn't have to be a real instance of InputSectionBase class.
In this patch, we no longer instantiate Discarded section but instead
use -1 as a pointer value. This eliminates a global variable which
needed initialization at startup.
llvm-svn: 261761
This is a preparation for ICF. If we merge two sections, we want to
align the merged section at the largest alignment requirement.
That means we want to update the alignment value, which was
impossible before this patch because Header is a const value.
llvm-svn: 261712
There is nothing aarch64 specific in here. If a symbol can be preempted,
we need to copy the full relocation to the dynamic linker.
If a symbol cannot be preempted, we can make the dynamic linker life
easier and produce a relative relocation.
This is directly equivalent to R_X86_64_64 to R_x86_64_RELATIVE
conversion.
llvm-svn: 261678
This patch fixes the R_AARCH64_ABS64 relocation when used in shared mode,
where it requires a dynamic R_AARCH64_RELATIVE relocation. To correct set
the addend on the dynamic relocation (since it will be used by the dynamic
linker), a new TargetInfo specific hook was created (getDynRelativeAddend)
to get the correct addend based on relocation type.
The patch fixes the issues when creating shared library code against
{init,fini}_array, where it issues R_AARCH64_ABS64 relocation against
local symbols.
llvm-svn: 261651
This reduces the .rodata of scyladb from 4501932 to 4334639 bytes (1.038
times smaller).
I don't think it is critical to support tail merging, just exact
duplicates, but given the code organization it was actually a bit easier
to support both.
llvm-svn: 261327
Previously, we added garbage-collected symbols to the symbol table
and filter them out when we were writing symbols to the file. In
this patch, garbage-collected symbols are filtered out from beginning.
llvm-svn: 261064
Previously, if both A and B are ".ctors", both compCtors(A, B) and
compCtors(B, A) are true, which is a violation of the strict weak
ordering because such function is not antisymmetric.
llvm-svn: 260633
Global constructors and destructors are guaranteed to be called
in the order as they appear in a translation unit. So we don't want
to mess up the order if they have the same priority.
llvm-svn: 260463
This basically reverts commit r260073 because it is found that
augmentation strings don't always start with "zR". It is reported
as https://llvm.org/bugs/show_bug.cgi?id=26541.
llvm-svn: 260294
This is the function equivalent of a copy relocation.
Since functions are expected to change sizes, we cannot use copy
relocations. In situations where one would be needed, what is done
instead is:
* Create a plt entry
* Output an undefined symbol whose addr is the plt entry.
The dynamic linker makes sure any shared library uses the plt entry as
the function address.
llvm-svn: 260224
I found that the handling of 'L' character in an augmentation string is
wrong because 'L' means that the next byte is the length field. I could
have fixed that by just skipping the next byte, but I decided to take a
different approach.
Teaching the linker about all the types of CIE internal records just to
skip them is silly. And the code doing that is not actually executed now
(that's why the bug did not cause any issue.) It is because the 'R' field,
which we want to read, is always at beginning of the CIE. So I reduced
the code dramatically by assuming that that's always the case. I want to
see how it works in the wild. If it doesn't work, we can roll this back
(with a fix for 'L').
http://reviews.llvm.org/D16939
llvm-svn: 260073
I removed "CIE/FIE size is too large" error because that was not
checking for correct error conditions. [UINT_MAX - 4, UINT_MAX) is
a correct range as a size of a CIE/FDE record. It's just that the
size cannot be larger than the section size.
llvm-svn: 259951
The variable was marking various cases where a symbol must be included
in the dynamic symbol table. Being used by a dynamic relocation was only
one of them.
llvm-svn: 259889
The previous names contained "Local" and "Current", but what we
are handling is always local and current, so they were redundant.
TlsIndex comes from "tls_index" struct that Ulrich Drepper is using
in this document to describe this data structure in GOT.
llvm-svn: 259852
Another case where we currently have almost duplicated code is the
creation of dynamic relocations. First to decide if we need one, then to
decide what to write.
This patch fixes it by passing more information from the relocation scan
to the section writing code. This is the same idea used for r258723.
I actually think it should be possible to simplify this further by
reordering things a bit in the writer. For example, we should be able to
represent almost every position in the file with an OutputSeciton and
offset. When writing it out we then just need to add the offset to the
OutputSection VA.
llvm-svn: 259829
-Bsymbolic-functions:
When creating a shared library, bind references to global
function symbols to the definition within the shared library, if any.
This patch also fixed behavior of already existent -Bsymbolic:
previously PLT entries were created even if -Bsymbolic was specified.
Differential revision: http://reviews.llvm.org/D16411
llvm-svn: 259481
Previously, the methods to get symbol addresses were somewhat scattered
in many places. You can use getEntryAddr returns the address of the symbol,
but if you want to get the GOT address for the symbol, you needed to call
Out<ELFT>::Got->getEntryAddr(Sym). This change adds new functions, getVA,
getGotVA, getGotPltVA, and getPltVA to SymbolBody, so that you can use
SymbolBody as the central place to ask about symbols.
http://reviews.llvm.org/D16710
llvm-svn: 259404
Rui Ueyama