Summary: This will allow us to remove the AMDGPU support from old ELF.
Reviewers: rafael, ruiu
Differential Revision: http://reviews.llvm.org/D15895
llvm-svn: 257023
String tables in unstripped executable files are fairly large in size.
For example, lld's executable file is about 34.4 MB in my environment,
and of which 3.5 MB is the string table. Efficiency of string table
construction matters.
Previously, the string table was built in an inefficient way. We used
StringTableBuilder to build that and enabled string tail merging,
although tail merging is not effective for the symbol table (you can
only make the string table 0.3% smaller for lld.) Tail merging is
computation intensive task and slow.
This patch eliminates string tail merging.
I changed the way of adding strings to the string table in this patch
too. Previously, strings were added using add() and the same strings
were then passed to getOffset() to get their offsets in the string table.
In this way, getOffset() needs to look up a hash table to get offsets
for given strings. This is a violation of "we look up the symbol table
(or a hash table) only once for each symbol" dogma of the new LLD's
design. Hash table lookup for long C++ mangled names is slow.
I eliminated that lookup in this patch.
In total, this patch improves link time of lld itself about 12%
(3.50 seconds -> 3.08 seconds.)
llvm-svn: 257017
In a UI such as XCode, it can group the headers for a library with that library.
This is done in the CMakeLists.txt for the library itself by setting the path(s)
as ADDITIONAL_HEADER_DIRS.
LLVM already does this for all of its libraries, so just adding this to lld to
make things easier. Should be NFC.
llvm-svn: 257002
In a UI such as XCode, LLVM source files are in 'libraries' while clang
files are in 'clang libraries'.
This change moves the lld source to 'lld libraries' to make code browsing easier.
It should be NFC as the build itself is still the same, just the structure in a
UI differs.
llvm-svn: 257001
MipsReginfoInputSection is basically just a container of Elf_Mips_Reginfo
struct. This patch makes that struct directly accessible from others.
llvm-svn: 256984
The fixup content we encode here should be the offset from the
fixup location back to the last nonlocal label. We were only encoding
the address of the fixup, and not taking in to account the base address
of the atom we are in.
Updated the test case here to have a text section which will come before
the data section where the relocation lives. .data being at offset 0 had
previously been hiding this bug.
llvm-svn: 256974
Unlike ObjectFile or ArchiveFile, SharedFile had two parse functions,
parseSoName() and parse(). parse must have been called after parseSoName,
but that requirement was not obvious from their names. (So it looked
like you could call parse() on a shared object file right away.)
This patch rename parseRest. It is now obvious that there's no single
parse function for the shared object file.
llvm-svn: 256898
Previously, we handle archive files with --whole-archive this way:
create instances of ArchiveFile, call getMembers to obtain memory
buffers of archive members, and create ObjectFiles for the members.
We didn't call anything except getMembers if --whole-archive was
specified.
I noticed that we didn't actually have to create ArchiveFile instaces
at all for that case. All we need is to get a list of memory buffers
for members, which can be done by a non-member function.
This patch removes getMembers member function from ArchiveFile.
Also removed unnecessary code for memory management.
llvm-svn: 256893
The final section order in relocatable files was just a side effect
of the atom sorter. This meant that sections like __data were before
__text because __data has RW permissions and __text RX and RW was less
than RX in our enum.
Final linked images had an actual section/segment sorter. There was no
reason for the difference, so simplify a bunch of code and just use the
same sorted for everything.
Reviewed by Lang Hames.
http://reviews.llvm.org/D15868
llvm-svn: 256786
The encoded value should be an offset from the fixup location, which
means that it should take in to account the fixup offset in its section.
We weren't subtracting the base address of the atom, which meant that when
we parsed the file again for a round trip, we had 2x the atom address in our
target address.
I've also improved comments for these to try and describe what is going on.
There's no test case right now, as the bug is only exhibited when __data is at
a non-zero address in a -r link. A commit will soon sort the sections differently
and move __data to after __text. Then these relocations in
test/mach-o/parse-data-relocs-x86_64.yaml will test for this bug.
llvm-svn: 256779
Test did not catch this either, so I`ll improve it and recommit later.
Original commit message:
[ELF] - Optimize .eh_frame section: remove CIE if all FDEs referencing it were removed.
This patch performs little optimization for eh_frame section.
If all FDE`s that referenced CIE are removed then CIE is also removed from output.
That can happen for example when dropping FDEs that point to dropped sections. Testcase showing that is included.
The same optimization was added to ld about 14 years ago: https://sourceware.org/ml/binutils/2001-12/msg00144.html, gold does not do that it seems.
Differential revision: http://reviews.llvm.org/D15564
llvm-svn: 256693
This patch performs little optimization for eh_frame section.
If all FDE`s that referenced CIE are removed then CIE is also removed from output.
That can happen for example when dropping FDEs that point to dropped sections. Testcase showing that is included.
The same optimization was added to ld about 14 years ago: https://sourceware.org/ml/binutils/2001-12/msg00144.html, gold does not do that it seems.
Differential revision: http://reviews.llvm.org/D15564
llvm-svn: 256638
The linker has to create __tls_get_addr, end and _end symbols.
Previously, these symbols were created in createSections().
But they are not actually related to creating output sections.
This patch moves code out of the function.
llvm-svn: 256441
Tom Stellard