It is required to fill up the GNU hash table section before its
finalize() method is called.
Differential Revision: http://reviews.llvm.org/D14196
llvm-svn: 251789
MachODefinedCustomSectionAtom.
The section names for these atoms are initialized from temporaries (e.g.
segName + "/" + sectName), so we can't use StringRef here.
llvm-svn: 251610
It is the GNU hash table section that should be reaponsible for storing its own
data and applying its requirements for the order to dynamic symbols.
Differential Revision: http://reviews.llvm.org/D14084
llvm-svn: 251502
GNU linkers accept both variants and at least for MIPS target gcc passes
joined variant of the '-m' option.
Differential Revision: http://reviews.llvm.org/D14133
llvm-svn: 251497
This matches ld.bfd and ld.gold behavior. The change is simple enough
and avoid trouble to consumers (they don't have to change their Makefiles).
Side note: found while trying to build FreeBSD base system with lld.
llvm-svn: 251408
There was a threading issue in the ICF code for COFF. That seems like
a venign bug in the sense that it doesn't produce an incorrect output,
but it oftentimes misses reducible sections. As a result, mergeable
sections could remain in outputs, which makes the output nondeterministic.
Basically the algorithm we are using for ICF is this: We group sections
so that identical sections will eventually be in the same group. Initially,
all sections are in one group. We split the group by relocation targets
until we get a convergence (if relocation targets are in different gruops,
the sections are different). Once a group is split, they will never be
merged.
Each section has a group ID. That variable itself is atomic, so there's
no threading issue at the level that we can use thread sanitizer.
The point is, when we split a group, we re-assign new group IDs to group
of sections. That are multiple separate writes to atomic varaibles.
Thus, splitting a group is not an atomic operation, and there's a small
chance that the other thread observes inconsistent group IDs.
Over-splitting is always "safe", so it will never create incorrect output.
I suspect that the nondeterminism stems from that point. However, I
cannot prove or fix that at this moment, so I'm going to avoid using
threads here.
llvm-svn: 251300
getFileOff functions defined for other classes return an offset
from beginning of the file. StringTableSection's getFileOff however
returned an offset from beginning of the section. That was confusing.
llvm-svn: 251192
This patch is an attempt to simplify assignAddresses function by splitting
it and using less variables. I tried to split the code to create PHDRs from
the code to assign addresses, but it didn't make this code simpler, so I
didn't do that in this patch.
llvm-svn: 251152
relocateOne is a function to apply a relocation. Previously, that
function took a pointer to Elf_Rel or Elf_Rela in addition to other
information that can be derived from the relocation entry. This patch
simplifies the parameter list. The new parameters, P or SA, are used
in the ELF spec to describe each relocation. These names make
relocateOne look like a mechanical, direct translation of the ELF spec.
llvm-svn: 251090
.eh_frame sections need to be preserved if they refer to live sections.
So the liveness relation is reverse for eh_frame sections. For now,
we simply preserve all .eh_frame sections. Thanks Rafael for pointing
this out. .jcr are kept for the same reason.
llvm-svn: 251068
Section garbage collection is a feature to remove unused sections
from outputs. Unused sections are sections that cannot be reachable
from known GC-root symbols or sections. Naturally the feature is
implemented as a mark-sweep garbage collector.
In this patch, I added Live bit to InputSectionBase. If and only
if Live bit is on, the section will be written to the output.
Starting from GC-root symbols or sections, a new function, markLive(),
visits all reachable sections and sets their Live bits. Writer then
ignores sections whose Live bit is off, so that such sections are
excluded from the output.
This change has small negative impact on performance if you use
the feature because making sections means more work. The time to
link Clang changes from 0.356s to 0.386s, or +8%.
It reduces Clang size from 57,764,984 bytes to 55,296,600 bytes.
That is 4.3% reduction.
http://reviews.llvm.org/D13950
llvm-svn: 251043
Rafael Espindola