This was a missing piece.
We started to print LMAs and information about assignments,
but did not do that for assignments outside of section declarations yet.
The patch implements it.
Differential revision: https://reviews.llvm.org/D45314
llvm-svn: 348468
The test breaks on buildbots that don't enable the x86 backend. Other
tests in this directory explicitly require x86, so this should do the
trick.
llvm-svn: 348466
This is a part of
https://bugs.llvm.org/show_bug.cgi?id=39885
Linker script specification says:
"You can specify a file name to include sections from a particular file. You would
do this if one or more of your files contain special data that needs to be at a
particular location in memory."
LLD did not accept this syntax. The patch implements it.
Differential revision: https://reviews.llvm.org/D55324
llvm-svn: 348463
Previously, we have a hash table containing strings and their offsets
to manage mergeable strings. Technically we can live without that, because
we can do binary search on a vector of mergeable strings to find a mergeable
strings.
We did have both the hash table and the binary search because we thought
that that is faster.
We recently observed that lld tend to consume more memory than gold when
building an output with debug info. A few percent of memory is consumed by
the hash table. So, we needed to reevaluate whether or not having the extra
hash table is a good CPU/memory tradeoff. I run a few benchmarks with and
without the hash table.
I got a mixed result for the benchmark. We observed a regression for some
programs by removing the hash table (that's what we expected), but we also
observed that performance imrpovements for some programs. This is perhaps
due to reduced memory usage.
Differential Revision: https://reviews.llvm.org/D55234
llvm-svn: 348401
Previously these were dropped. We now understand them sufficiently
well to start emitting them. From the debugger's perspective, this
now enables us to have debug info about typedefs (both global and
function-locally scoped)
Differential Revision: https://reviews.llvm.org/D55228
llvm-svn: 348306
Patch from Andrew Kelley.
For context, see https://bugs.llvm.org/show_bug.cgi?id=39862
The use case is embedded / OS programming where the kernel wants
access to its own debug info via mapped dwarf info. I have a proof of
concept of this working, using this linker script snippet:
.rodata : ALIGN(4K) {
*(.rodata)
__debug_info_start = .;
KEEP(*(.debug_info))
__debug_info_end = .;
__debug_abbrev_start = .;
KEEP(*(.debug_abbrev))
__debug_abbrev_end = .;
__debug_str_start = .;
KEEP(*(.debug_str))
__debug_str_end = .;
__debug_line_start = .;
KEEP(*(.debug_line))
__debug_line_end =
.;
__debug_ranges_start
= .;
KEEP(*(.debug_ranges))
__debug_ranges_end
= .;
}
Differential revision: https://reviews.llvm.org/D55276
llvm-svn: 348291
When linking the linux kernel on ppc64le
ld.lld -EL -m elf64lppc -Bstatic --orphan-handling=warn --build-id -o
.tmp_vmlinux1 -T ./arch/powerpc/kernel/vmlinux.lds --whole-archive
built-in.a --no-whole-archive --start-group lib/lib.a --end-group
ld.lld: error: discarding .rela.plt section is not allowed
The linker script discards with the following matches
*(.glink .iplt .plt .rela* .comment)
Differential Revision: https://reviews.llvm.org/D54871
llvm-svn: 348258
When linking the linux kernel on ppc64 and ppc
ld.lld: error: unrecognized reloc 11
11 is PPC_REL14 and PPC64_REL14
Differential revision: https://reviews.llvm.org/D54868
llvm-svn: 348255
At least on Linux, if a file size given to FileOutputBuffer is greater
than 2^63, it fails with "Invalid argument" error, which is not a
user-friendly error message. With this patch, lld prints out "output
file too large" instead.
llvm-svn: 348153
There is no need to check that In.DynSymTab != nullptr,
because `includeInDynsym` already checks for `!Config->HasDynSymTab`
and `HasDynSymTab` is the pre-condition for In.DynSymTab creation.
llvm-svn: 348143
Now LLD might build the broken/incomplete .gdb_index when some DWARF v5
sections (like .debug_rnglists and .debug_addr) are used.
Particularly, for the case above, we emit an empty address area.
A test case is provided and patch fixes the issue.
Differential revision: https://reviews.llvm.org/D55109
llvm-svn: 348119
We initialize .text section with 0xcc (INT3 instruction), so we need to
explicitly write data even if it is zero if it can be in a .text section.
If you specify /merge:.rdata=.text, .rdata (which contains .idata) is put
to .text, so we need to do this.
Fixes https://bugs.llvm.org/show_bug.cgi?id=39826
Differential Revision: https://reviews.llvm.org/D55098
llvm-svn: 348000
The _GLOBAL_OFFSET_TABLE_ is a linker defined symbol that is placed at
some location relative to the .got, .got.plt or .toc section. On some
targets such as Arm the correctness of some code sequences using a
relocation to _GLOBAL_OFFSET_TABLE_ depend on the value of the symbol
being in the linker defined place. Follow the ld.gold example and give
a multiple symbol definition error. The ld.bfd behaviour is to ignore the
definition in the input object and redefine it, which seems like it could
be more surprising.
fixes pr39587
Differential Revision: https://reviews.llvm.org/D54624
llvm-svn: 347854
This is an reland of rL343155 which got reverted because
of a sphinx failure on the buildbot.
Differential Revision: https://reviews.llvm.org/D54982
llvm-svn: 347830
Summary:
This reinstates what I originally intended to do in D54361.
It removes the assumption that .debug_gnu_pubnames has increasing CuOffset.
Now we do better than gold here: when .debug_gnu_pubnames contains
multiple sets, gold would think every set has the same CU index as the
first set (incorrect).
Reviewed By: ruiu
Reviewers: ruiu, dblaikie, espindola
Subscribers: emaste, arichardson, arphaman, llvm-commits
Differential Revision: https://reviews.llvm.org/D54483
llvm-svn: 347820
This patch also makes getPltEntryOffset a non-member function because
it doesn't depend on any private members of the TargetInfo class.
I tried a few different ideas, and it seems this change fits in best to me.
Differential Revision: https://reviews.llvm.org/D54981
llvm-svn: 347781
The DT_PLTRELSZ dynamic tag is calculated using the size of the
OutputSection containing the In.RelaPlt InputSection. This will work for the
default no linker script case and the majority of linker scripts.
Unfortunately it doesn't work for some 'almost' sensible linker scripts. It
is permitted by ELF to have a single OutputSection containing both
In.RelaDyn, In.RelaPlt and In.RelaIPlt. It is also permissible for the range
of memory [DT_RELA, DT_RELA + DT_RELASZ) and the range
[DT_JMPREL, DT_JMPREL + DT_JMPRELSZ) to overlap as long as the the latter
range is at the end.
To support this type of linker script use the specific InputSection sizes.
Fixes pr39678
Differential Revision: https://reviews.llvm.org/D54759
llvm-svn: 347736
The number of sections is used in assignAddresses (in
finalizeAddresses) and the space for all sections is permanent from
that point on, even if we later decide we won't write some of them.
The VirtualSize field also gets calculated in assignAddresses, so we
need to manually check whether the section is empty here instead.
Differential Revision: https://reviews.llvm.org/D54495
llvm-svn: 347704
Summary:
This speeds up linking clang.exe/pdb with /DEBUG:GHASH by 31%, from
12.9s to 9.8s.
Symbol records are typically small (16.7 bytes on average), but we
processed them one at a time. CVSymbol is a relatively "large" type. It
wraps an ArrayRef<uint8_t> with a kind an optional 32-bit hash, which we
don't need. Before this change, each DbiModuleDescriptorBuilder would
maintain an array of CVSymbols, and would write them individually with a
BinaryItemStream.
With this change, we now add symbols that happen to appear contiguously
in bulk. For each .debug$S section (roughly one per function), we
allocate two copies, one for relocation, and one for realignment
purposes. For runs of symbols that go in the module stream, which is
most symbols, we now add them as a single ArrayRef<uint8_t>, so the
vector DbiModuleDescriptorBuilder is roughly linear in the number of
.debug$S sections (O(# funcs)) instead of the number of symbol records
(very large).
Some stats on symbol sizes for the curious:
PDB size: 507M
sym bytes: 316,508,016
sym count: 18,954,971
sym byte avg: 16.7
As future work, we may be able to skip copying symbol records in the
linker for realignment purposes if we make LLVM write them aligned into
the object file. We need to double check that such symbol records are
still compatible with link.exe, but if so, it's definitely worth doing,
since my profile shows we spend 500ms in memcpy in the symbol merging
code. We could potentially cut that in half by saving a copy.
Alternatively, we could apply the relocations *after* we iterate the
symbols. This would require some careful re-engineering of the
relocation processing code, though.
Reviewers: zturner, aganea, ruiu
Subscribers: hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D54554
llvm-svn: 347687
This is https://bugs.llvm.org/show_bug.cgi?id=38074.
The issue is that when calling a function, LLD generates a
.got entry that points to the IFUNC resolver function when
instead, it should use the PLT entries properly for
handling the IFUNC.
So we should create a got entry that points to PLT entry,
which itself loads the value from
.got.plt, relocated with R_*_IRELATIVE to make things work.
Patch do that.
Differential revision: https://reviews.llvm.org/D54314
llvm-svn: 347650
The changes to the instructions performed by TLS relaxation and the errata
patching are performed with relocations. As these are applied so late the
errata scanning won't see the changes in the section data made by the TLS
relaxation. This can lead to a TLS relaxed sequence being patched when it
doesn't need to be.
The fix checks to see if there is a R_RELAX_TLS_IE_TO_LE instruction at the
same address as the ADRP as this indicates the presence of a relaxation
of a sequence that might get recognised as a patch.
Differential Revision: https://reviews.llvm.org/D54854
llvm-svn: 347649
This is https://bugs.llvm.org//show_bug.cgi?id=38978
Spec says that:
"Objects may be built with the -z nodefaultlib option to
suppress any search of the default locations at runtime.
Use of this option implies that all the dependencies of an
object can be located using its runpaths.
Without this option, which is the most common case, no
matter how you augment the runtime linker's library
search path, its last element is always /usr/lib for 32-bit
objects and /usr/lib/64 for 64-bit objects."
The patch implements this option.
Differential revision: https://reviews.llvm.org/D54577
llvm-svn: 347647
GNU ld, which doesn't generate PDBs, can optionally generate a
build id by passing the --build-id option. LLD's MinGW frontend knows
about this option but ignores it, as I had falsely assumed that LLD
already generated build IDs even in those cases.
If debug info is requested and no PDB path is set, generate a
build id signature as a hash of the binary itself. This allows
associating a binary to a minidump, even if debug info isn't
written in PDB form by the linker.
Differential Revision: https://reviews.llvm.org/D54828
llvm-svn: 347645
Summary:
MSVC does this, and we should to.
The .gfids table is a table of RVAs, so it's impossible for a DLL to
indicate that an imported symbol is address taken. Therefore, exports
appear to be listed as address taken by the DLL that exports them.
This fixes an issue that Firefox ran into here:
https://bugzilla.mozilla.org/show_bug.cgi?id=1485016#c12
In Firefox, the export directive came from a .def file, but we need to
do this for any kind of export.
Reviewers: dmajor, hans, amccarth, alex
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D54723
llvm-svn: 347623
The benefits are:
a) Performance (very minor): it removes a heap allocation of the std::function constructor (template<class F> function(F f))
b) Clarity: it suggests that the callable's lifetime should end after the callee returns. Such callback is widely used in llvm. lld also uses it a lot.
Reviewers: ruiu, rnk, pcc
Reviewed By: ruiu
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D54813
llvm-svn: 347620
On my machine this reduced median link time of lld-speed-test/chrome
from 2.68s to 2.41s. It also reduces link time of Chrome for Android
with a prototype compiler change that causes the compiler to create
large numbers of identical (modulo relocations) sections from >15
minutes to a few seconds.
Differential Revision: https://reviews.llvm.org/D54773
llvm-svn: 347594
Summary: They have an additional `ThreadsEnabled` check, which does not matter much.
Reviewers: pcc, ruiu, rnk
Reviewed By: ruiu
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D54812
llvm-svn: 347587
When we are in a error state, script parser will not parse the -defsym
expression and hence will not tokenize it. Then ScriptLexer::Pos will be 0
and LLD will assert and crash here:
MemoryBufferRef ScriptLexer::getCurrentMB() {
assert(!MBs.empty() && Pos > 0); // Bang !
Solution - stop parsing the defsym in a error state. That is consistent
with the regular case (when we parse the linker script).
llvm-svn: 347549
We explicitly call finalizeContents() only once for
DynamicSection. The code testing we do not do it twice is
just excessive.
It could be an assert, but we don't do
that for other sections, so does not seem we
should do it here too.
llvm-svn: 347543
Now it returns Symbol. This should be NFC that
avoids doing cast at the caller's sides.
Differential revision: https://reviews.llvm.org/D54627
llvm-svn: 347455
Previously we were taking over 13 minutes to link Firefox's xul.dll
on ARM64; this reduces link time to around 18s on my machine.
The root cause of the problem was that all of the input .pdata sections
had the same unrelocated section data and therefore the same hash,
which made segregation quadratic in the number of .pdata sections. The
reason why we weren't observing this on other architectures was that
ARM has a different .pdata format. On non-ARM the format is (start
address, end address, .xdata), which caused the size of the function
to appear in the unrelocated section data where the end address field
is. However, the ARM format omits the end address field.
Fixes PR39667.
Differential Revision: https://reviews.llvm.org/D54809
llvm-svn: 347429
Summary:
This fixes PR39711: -static -z retpolineplt does not produce retpoline PLT header.
-z now is not relevant.
Statically linked executable does not have PLT, but may have IPLT with no header. When -z retpolineplt is specified, however, the repoline PLT header should still be emitted.
I've checked that this fixes the FreeBSD reproduce in PR39711 and a Linux program statically linked against glibc. The programm print "Hi" rather than SIGILL/SIGSEGV.
getPltEntryOffset may look dirty after this patch, but it can be cleaned up later.
Another possible improvement is that when there are non-preemptible IFUNC symbols (rare case, e.g. -Bsymbolic), both In.Plt and In.Iplt can be non-empty and we'll emit the retpoline PLT header twice.
Reviewers: espindola, emaste, chandlerc, ruiu
Reviewed By: emaste
Subscribers: emaste, arichardson, krytarowski, llvm-commits
Differential Revision: https://reviews.llvm.org/D54782
llvm-svn: 347404
When REQUIRES: ARM is used the test is skipped as ARM is not recognized.
Change to REQUIRES: arm so that it is run. This required updating one of the
tests due to changes in expected output.
Differential Revision: https://reviews.llvm.org/D54786
llvm-svn: 347388
Don't use a uint32_t*, use a ulittle32_t* to make this correct
on big endian systems.
Patch by James Clarke
Differential Revision: https://reviews.llvm.org/D54421
llvm-svn: 347349
Summary:
When --noinhibit-exec is used, ld.bfd/gold emit errors but allow to produce corrupted executable, which is handy for debugging purpose. lld's --noinhibit-exec has a different meaning and changes some errors to warnings. This patch replaces "error" with "errorOrWarn" to exploit that property.
We may revisit this: if we should keep them as errors (as ld.bfd/gold do) but allow to produce a (corrupted) executable.
Reviewers: ruiu, grimar, espindola
Reviewed By: grimar
Subscribers: Timmmm, jhenderson, emaste, arichardson, llvm-commits
Differential Revision: https://reviews.llvm.org/D54651
llvm-svn: 347327
Summary:
At the beginning of `assignIndexes() function, when `FunctionIndex` and
`GlobalIndex` variables are created, `InputFunctions` and `InputGlobals`
vectors are guaranteed to be empty, because those vectors are only
populated in `assignIndexes()` function. Current code looks like they
are nonempty, so this patch deletes them for better readability.
Reviewers: sbc100
Subscribers: dschuff, jgravelle-google, sunfish, llvm-commits
Differential Revision: https://reviews.llvm.org/D54687
llvm-svn: 347272
Summary: This patch implementation the handler for ARM_V4BX. This relocation is used by GNU runtime files and other armv4 applications.
Patch by Yin Ma
Reviewers: espindola, MaskRay, ruiu, peter.smith, pcc
Reviewed By: ruiu
Subscribers: yinma, pcc, peter.smith, MaskRay, rovka, efriedma, emaste, javed.absar, arichardson, kristof.beyls, chrib, llvm-commits
Differential Revision: https://reviews.llvm.org/D53444
llvm-svn: 347077
Current value using as a trap instruction (0xefefefef) is not a good choice
for MIPS because it's a valid MIPS instruction `swc3 $15,-4113(ra)`. This
patch replaces 0xefefefef by 0x04170001. For all MIPS ISA revisions before
R6, this value is just invalid instruction. Starting from MIPS R6 it's
a valid instruction `sigrie 1` which signals a Reserved Instruction exception.
mips-traps.s test case is added to test trap encoding. Other test cases
are modified to remove redundant checking.
Differential revision: https://reviews.llvm.org/D54154
llvm-svn: 347029
Remove the default initializer for TrapInstr; all subclasses overwrite
the defaults in their constructors anyway.
This fixes compilation errors like these, with GCC 5.4 on Ubuntu 16.04,
present since SVN r346893:
In file included from ../tools/lld/ELF/Arch/AArch64.cpp:12:0:
../tools/lld/ELF/Target.h:125:49: error: array must be initialized with a brace-enclosed initializer
std::array<uint8_t, 4> TrapInstr = {0, 0, 0, 0};
^
../tools/lld/ELF/Target.h:125:49: error: too many initializers for ‘std::array<unsigned char, 4ul>’
Differential Revision: https://reviews.llvm.org/D54569
llvm-svn: 346934
The uint32_t type does not clearly convey that these fields are interpreted
in the target endianness. Converting them to byte arrays should make this
more obvious and less error-prone.
Patch by James Clarke
Differential Revision: http://reviews.llvm.org/D54207
llvm-svn: 346893
On PowerPC64, when a function call offset is too large to encode in a call
instruction the address is stored in a table in the data segment. A thunk is
used to load the branch target address from the table relative to the
TOC-pointer and indirectly branch to the callee. When linking position-dependent
code the addresses are stored directly in the table, for position-independent
code the table is allocated and filled in at load time by the dynamic linker.
For position-independent code the branch targets could have gone in the .got.plt
but using the .branch_lt section for both position dependent and position
independent binaries keeps it consitent and helps keep this PPC64 specific logic
seperated from the target-independent code handling the .got.plt.
Differential Revision: https://reviews.llvm.org/D53408
llvm-svn: 346877
The R_AARCH64_ADR_PREL_PG_HI21 relocation type is given the R_PAGE_PC
RelExpr. This can be transformed to R_PLT_PAGE_PC via toPlt().
Unfortunately the resolution is identical to R_PAGE_PC so instead of
getting the address of the PLT entry we get the address of the symbol
which may not be correct in the case of static ifuncs. The fix is to
handle the cases separately and use getPltVA() + A with R_PLT_PAGE_PC.
Differential Revision: https://reviews.llvm.org/D54474
llvm-svn: 346863
- Make mergeSymbolRecords a method of PDBLinker to reduce the number of
parameters it needs.
- Remove a stale FIXME comment about error handling. We already drop
unknown symbol records, log them, and continue.
- Update a comment about why we're copying the symbol record. We do it
to realign the record. We can already mutate the symbol record memory,
it's memory allocated by relocateDebugChunk.
- Avoid the extra `CVSymbol NewSym` variable. We can mutate Sym in
place, which is best, since we're mutating the underlying record anyway.
llvm-svn: 346817
gdb-index-multiple-cu-2.s puts the symbol in question to another object file %t1.o, so that its CuIndex is affected by the number of CUs in %t.o
Also change `Kind:` in a comment to `Attributes:` as a follow-up of D54480 and D54481
llvm-svn: 346796
Summary:
NameTypeEntry::Type is a bit-packed value of CU index+attributes (https://sourceware.org/gdb//onlinedocs/gdb/Index-Section-Format.html), which is named cu_index_and_attrs in a local variable in gdb/dwarf2read.c:dw2_symtab_iter_next
The new name CuIndexAndAttrs is more meaningful.
Reviewers: ruiu, dblaikie, espindola
Reviewed By: dblaikie
Subscribers: emaste, aprantl, arichardson, JDevlieghere, arphaman, llvm-commits
Differential Revision: https://reviews.llvm.org/D54481
llvm-svn: 346794
Summary:
Idx passed to readPubNamesAndTypes was an index into Chunks, not an
index into the CU list. This would be incorrect if some .debug_info
section contained more than 1 DW_TAG_compile_unit.
In real world, glibc Scrt1.o is a partial link of start.os abi-note.o init.o and contains 2 CUs in debug builds.
Without this patch, any application linking such Scrt1.o would have invalid .gdb_index
The issue could be demonstrated by:
(gdb) py print(gdb.lookup_global_symbol('main'))
None
Reviewers: espindola, ruiu
Reviewed By: ruiu
Subscribers: Higuoxing, grimar, dblaikie, emaste, aprantl, arichardson, JDevlieghere, arphaman, llvm-commits
Differential Revision: https://reviews.llvm.org/D54361
llvm-svn: 346747
Summary:
The debug_info_offset value may be relocated.
This is lld side change of D54375.
Reviewers: ruiu, dblaikie, grimar, espindola
Subscribers: emaste, arichardson, JDevlieghere, llvm-commits
Differential Revision: https://reviews.llvm.org/D54376
llvm-svn: 346616
`--no-demangle` now also applies to the name section. This change
was motivated by the rust team that have a slightly different name
mangling scheme to the standard C++ itanium one and prefer to do their
de-mangling as a post-link setp.
Patch by Alex Crichton!
Differential Revision: https://reviews.llvm.org/D54279
llvm-svn: 346516
Summary:
Reuse the "referenced by" note diagnostic code that we already use for
undefined symbols. In my case, it turned this:
lld-link: error: relocation against symbol in discarded section: .text
lld-link: error: relocation against symbol in discarded section: .text
...
Into this:
lld-link: error: relocation against symbol in discarded section: .text
>>> referenced by libANGLE.lib(CompilerGL.obj):(.SCOVP$M)
>>> referenced by libANGLE.lib(CompilerGL.obj):(.SCOVP$M)
...
lld-link: error: relocation against symbol in discarded section: .text
>>> referenced by obj/third_party/angle/libGLESv2/entry_points_egl_ext.obj:(.SCOVP$M)
>>> referenced by obj/third_party/angle/libGLESv2/entry_points_egl_ext.obj:(.SCOVP$M)
...
I think the new output is more useful.
Reviewers: ruiu, pcc
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D54240
llvm-svn: 346427
Summary:
D53821 fixed the bogus MSVC (at least 2017) C4146 warning (unary minus applied on unsigned type)
by using std::numeric_limits<int32_t>::min().
The warning was because -2147483648 is incorrectly treated as unsigned long instead of long long)
Let's use INT32_MIN which is arguably more readable.
Note, on GCC or clang, -0x80000000 works fine (ILP64: long, LP64: long long).
Reviewers: ruiu, jhenderson, sfertile, espindola
Reviewed By: sfertile
Subscribers: emaste, nemanjai, arichardson, kbarton, jsji, llvm-commits
Differential Revision: https://reviews.llvm.org/D54200
llvm-svn: 346356
Used for WebAssembly threads proposal. Add a flag --shared-memory
which sets the IS_SHARED bit in WasmLimits
Differential Revision: https://reviews.llvm.org/D54130
llvm-svn: 346248
Summary: llvm-readobj/readelf accepts both -s and -S as aliases for --sections. However with GNU readelf only -S means --section, and -s means --symbols. I would like to make llvm-readelf more compatible.
Reviewers: MaskRay, espindola
Reviewed By: MaskRay
Subscribers: emaste, arichardson, steven_wu, dexonsmith, llvm-commits
Differential Revision: https://reviews.llvm.org/D54118
llvm-svn: 346164
This change allows for link-time merging of debugging information from
Microsoft precompiled types OBJs compiled with cl.exe /Z7 /Yc and /Yu.
This fixes llvm.org/PR34278
Differential Revision: https://reviews.llvm.org/D45213
llvm-svn: 346154
Summary:
It is difficult to touch a file with a relative mtime across different OSes as POSIX touch -d is rigid. While we may construct relative timestamps with `date`, POSIX date is inadequate to do so as various OSes' date do not agree on a common format (OpenBSD uses `date -r seconds`, FreeBSD uses `date -v-2M` while GNU accepts `-d '-2 min'`)
Just use python os.utime()
Original description:
The case may randomly fail if we test it with command "
while llvm-lit tools/lld/test/ELF/lto/cache.ll; do true; done". It is because the llvmcache-foo file is younger than llvmcache-349F039B8EB076D412007D82778442BED3148C4E and llvmcache-A8107945C65C2B2BBEE8E61AA604C311D60D58D6. But due to timestamp precision reason their timestamp is the same. Given the same timestamp, the file prune policy is to remove bigger size file first, so mostly foo file is removed for its bigger size. And the files size is under threshold after deleting foo file. That's what test case expect.
However sometimes, the precision is enough to measure that timestamp of llvmcache-349F039B8EB076D412007D82778442BED3148C4E and llvmcache-A8107945C65C2B2BBEE8E61AA604C311D60D58D6 are smaller than foo, so llvmcache-349F039B8EB076D412007D82778442BED3148C4E and llvmcache-A8107945C65C2B2BBEE8E61AA604C311D60D58D6 are deleted first. Since the files size is still above the file size threshold after deleting the 2 files, the foo file is also deleted. And then the test case fails, because it expect only one file should be deleted instead of 3.
The fix is to change the timestamp of llvmcache-foo file to meet the thinLTO prune policy.
The same fix is applied to llvm code at https://reviews.llvm.org/D52452.
Patch by Luo Yuanke.
Reviewers: ruiu, craig.topper, smaslov, Jianping, espindola, LuoYuanke, tejohnson
Reviewed By: tejohnson
Subscribers: sbc100, krytarowski, aheejin, llvm-commits, dexonsmith, steven_wu, arichardson, inglorion, emaste, bjope, rupprecht
Differential Revision: https://reviews.llvm.org/D54039
llvm-svn: 346006
Summary:
The case may randomly fail if we test it with command "
while llvm-lit tools/lld/test/ELF/lto/cache.ll; do true; done". It is because the llvmcache-foo file is younger than llvmcache-349F039B8EB076D412007D82778442BED3148C4E and llvmcache-A8107945C65C2B2BBEE8E61AA604C311D60D58D6. But due to timestamp precision reason their timestamp is the same. Given the same timestamp, the file prune policy is to remove bigger size file first, so mostly foo file is removed for its bigger size. And the files size is under threshold after deleting foo file. That's what test case expect.
However sometimes, the precision is enough to measure that timestamp of llvmcache-349F039B8EB076D412007D82778442BED3148C4E and llvmcache-A8107945C65C2B2BBEE8E61AA604C311D60D58D6 are smaller than foo, so llvmcache-349F039B8EB076D412007D82778442BED3148C4E and llvmcache-A8107945C65C2B2BBEE8E61AA604C311D60D58D6 are deleted first. Since the files size is still above the file size threshold after deleting the 2 files, the foo file is also deleted. And then the test case fails, because it expect only one file should be deleted instead of 3.
The fix is to change the timestamp of llvmcache-foo file to meet the thinLTO prune policy.
The same fix is applied to llvm code at https://reviews.llvm.org/D52452.
Patch by Luo Yuanke.
Reviewers: ruiu, craig.topper, smaslov, Jianping, espindola, LuoYuanke
Subscribers: rupprecht, bjope, emaste, inglorion, arichardson, steven_wu, dexonsmith, llvm-commits
Differential Revision: https://reviews.llvm.org/D53123
llvm-svn: 345977
Summary:
D52830 sets sh_link to .symtab in static link, which breaks executable stripped by GNU strip.
It may also be odd that .rela.plt (SHF_ALLOC) points to .symtab (non-SHF_ALLOC).
Change the logic on pcc's suggestion.
Before:
% clang -fuse-ld=lld -static -xc =(printf 'int main(){}') # or gcc
% strip a.out; ./a.out
unexpected reloc type in static binary[1] 61634 segmentation fault ./a.out
Reviewers: ruiu, grimar, emaste, espindola
Reviewed By: ruiu
Subscribers: pcc, arichardson, llvm-commits
Differential Revision: https://reviews.llvm.org/D53993
llvm-svn: 345899
This patch should not introduce any behavior changes. It consists of
mostly one of two changes:
1. Replacing fall through comments with the LLVM_FALLTHROUGH macro
2. Inserting 'break' before falling through into a case block consisting
of only 'break'.
We were already using this warning with GCC, but its warning behaves
slightly differently. In this patch, the following differences are
relevant:
1. GCC recognizes comments that say "fall through" as annotations, clang
doesn't
2. GCC doesn't warn on "case N: foo(); default: break;", clang does
3. GCC doesn't warn when the case contains a switch, but falls through
the outer case.
I will enable the warning separately in a follow-up patch so that it can
be cleanly reverted if necessary.
Reviewers: alexfh, rsmith, lattner, rtrieu, EricWF, bollu
Differential Revision: https://reviews.llvm.org/D53950
llvm-svn: 345882
This is https://bugs.llvm.org/show_bug.cgi?id=39493.
We crashed previously because did not handle /DISCARD/ properly
when -r was used. I think it is uncommon to use scripts with -r, though I see
nothing wrong to handle the /DISCARD/ so that we will not crash at least.
Differential revision: https://reviews.llvm.org/D53864
llvm-svn: 345819
Summary:
There are really three different kinds of TLS layouts:
* A fixed TLS-to-TP offset. On architectures like PowerPC, MIPS, and
RISC-V, the thread pointer points to a fixed offset from the start
of the executable's TLS segment. The offset is 0x7000 for PowerPC
and MIPS, which allows a signed 16-bit offset to reach 0x1000 of
per-thread implementation data and 0xf000 of the application's TLS
segment. The size and layout of the TCB isn't relevant to the static
linker and might not be known.
* A fixed TCB size. This is the format documented as "variant 1" in
Ulrich Drepper's TLS spec. The thread pointer points to a 2-word TCB
followed by the executable's TLS segment. The first word is always
the DTV pointer. Used on ARM. The thread pointer must be aligned to
the TLS segment's alignment, possibly creating alignment padding.
* Variant 2. This format predates variant 1 and is also documented in
Drepper's TLS spec. It allocates the executable's TLS segment before
the thread pointer, apparently for backwards-compatibility. It's
used on x86 and SPARC.
Factor out an lld:🧝:getTlsTpOffset() function for use in a
follow-up patch for Android. The TcbSize/TlsTpOffset fields are only used
in getTlsTpOffset, so replace them with a switch on Config->EMachine.
Reviewers: espindola, ruiu, PkmX, jrtc27
Reviewed By: ruiu, PkmX, jrtc27
Subscribers: jyknight, emaste, sdardis, nemanjai, javed.absar, arichardson, kristof.beyls, kbarton, fedor.sergeev, atanasyan, PkmX, jsji, llvm-commits
Differential Revision: https://reviews.llvm.org/D53905
llvm-svn: 345775
Summary: .rela.plt may only contain R_*_{,I}RELATIVE relocations and not need a symbol table link. bfd/gold fallbacks to sh_link=0 in this case. Without this patch, ld.lld --strip-all caused lld to dereference a null pointer.
Reviewers: ruiu, grimar, espindola
Reviewed By: ruiu
Subscribers: emaste, arichardson, llvm-commits
Differential Revision: https://reviews.llvm.org/D53881
llvm-svn: 345648
Visual Studio has a bug where it converts the integer literal 2147483648
into an unsigned int instead of a long long (i.e. it follows C89 rules).
The bug has been reported as:
https://developercommunity.visualstudio.com/content/problem/141813/-2147483648-c4146-error.html.
Because of this bug, we were getting a signed/unsigned comparison
warning in VS2015 from the old code (the subsequent unary negation had
no effect on the type).
Reviewed by: sfertile
Differential Revision: https://reviews.llvm.org/D53821
llvm-svn: 345579
Summary: There are too many reasonable cases that would be considered unorderable.
Reviewers: ruiu, espindola, Bigcheese
Reviewed By: ruiu
Subscribers: grimar, emaste, arichardson, llvm-commits
Differential Revision: https://reviews.llvm.org/D53669
llvm-svn: 345322
Out::DebugInfo was used only by GdbIndex class to determine if
we need to create a .gdb_index section, but we can do the same
check without it.
Added a test that this patch doesn't change the existing behavior.
llvm-svn: 345058
Summary:
During upgrading of the FreeBSD source tree with lld 7.0.0, I noticed
that it started complaining about `crt1.o` having an "index past the
end of the symbol table".
Such a symbol table looks approximately like this, viewed with `readelf
-s` (note the `Ndx` field being messed up):
```
Symbol table '.symtab' contains 4 entries:
Num: Value Size Type Bind Vis Ndx Name
0: 00000000 0 NOTYPE LOCAL DEFAULT UND
1: 00000000 0 SECTION LOCAL DEFAULT 1
2: 00000000 0 NOTYPE WEAK HIDDEN RSV[0xffff] __rel_iplt_end
3: 00000000 0 NOTYPE WEAK HIDDEN RSV[0xffff] __rel_iplt_start
```
At first, it seemed that recent ifunc relocation work had caused this:
<https://reviews.freebsd.org/rS339351>, but it turned out that it was
due to incorrect processing of the object files by lld, when using `-r`
(a.k.a. --relocatable).
Bisecting showed that rL324421 ("Convert a use of Config->Static") was
the commit where this new behavior began. Simply reverting it solved
the issue, and the `__rel_iplt` symbols had an index of `UND` again.
Looking at Rafael's commit message, I think he simply missed the
possibility of `--relocatable` being in effect, so I have added an
additional check for it.
I also added a simple regression test case.
Reviewers: grimar, ruiu, emaste, espindola
Reviewed By: ruiu
Subscribers: arichardson, krytarowski, llvm-commits
Differential Revision: https://reviews.llvm.org/D53515
llvm-svn: 345002
emulation.s is testing multiple architectures, which means it needs all
the corresponding backends enabled, which might not be true for all
developers (for example, I don't have PPC or MIPS enabled). Rather than
marking the entire test as unsupported for such developers, split it up
per backend to get better testing granularity.
Differential Revision: https://reviews.llvm.org/D53544
llvm-svn: 344986
Turns out I wasn't actually running this test locally, since I don't
build the PPC and MIPS backends. Whoops.
Perhaps this test should be split up per-architecture?
llvm-svn: 344980
We need this to support 32-bit ARM. Add test cases for emulation
handling for this architecture as well.
Differential Revision: https://reviews.llvm.org/D53539
llvm-svn: 344976
Summary:
Before, superfluous warnings were emitted for the following two cases:
1) When from symbol was in a discarded section.
The profile should be thought of as affiliated to the section.
It makes sense to ignore the profile if the section is discarded.
2) When to symbol was in a shared object.
The object file containing the profile may not know about the to
symbol, which can reside in another object file (useful profile) or a
shared object (not useful as symbols in the shared object are fixed
and unorderable). It makes sense to ignore the profile from the object
file.
Note, the warning when to symbol was undefined was suppressed in
D53044, which is still useful for --symbol-ordering-file=
This patch silences the warnings. The check is actually more relaxed (no
warnings if either From or To is not Defined) for simplicity and I don't
see a compelling reason to warn on more cases.
Reviewers: ruiu, davidxl, espindola, Bigcheese
Reviewed By: ruiu
Subscribers: emaste, arichardson, llvm-commits
Differential Revision: https://reviews.llvm.org/D53470
llvm-svn: 344974
This patch adds a support for OUTPUT_FORMAT linker script directive.
Since I'm not 100% confident with BFD names you can use in the directive
for all architectures, I added only a few in this patch. We can add
other names for other archtiectures later.
We still do not support triple-style OUTPUT_FORMAT directive, namely,
OUTPUT_FORMAT(bfdname, big, little). If you pass -EL (little endian)
or -EB (big endian) to the linker, GNU linkers pick up big or little
as a BFD name, correspondingly, so that you can use a single linker
script for bi-endian processor. I'm not sure if we really need to
support that, so I'll leave it alone for now.
Note that -m takes precedence over OUTPUT_FORAMT, but we always parse
a BFD name given to OUTPUT_FORMAT for error checking. You cannot write
an invalid name in the OUTPUT_FORMAT directive.
Differential Revision: https://reviews.llvm.org/D53495
llvm-svn: 344952
Summary:
SymbolTable::addAbsolute() was removed in rL344305.
To me this is more readable than the lambda named `Add` and in our
out-of-tree CHERI target we use addAbsolute() in another function.
Reviewers: ruiu, espindola
Reviewed By: ruiu
Subscribers: kristina, emaste, llvm-commits
Differential Revision: https://reviews.llvm.org/D53393
llvm-svn: 344842
Normally one wouldn't run into that case, but it is possible with
a little creative ordering of special libraries.
Differential Revision: https://reviews.llvm.org/D53388
llvm-svn: 344776
Adjusted the range check on a call instruction from 24 bits signed to
26 bits signed. While the instruction only encodes 24 bits, the target is
assumed to be 4 byte aligned, and the value that is encoded in the instruction
gets shifted left by 2 to form the offset. Also added a check that the offset is
indeed at least 4 byte aligned.
Differential Revision: https://reviews.llvm.org/D53401
llvm-svn: 344747
All the PassBuilder::parse interfaces now return descriptive StringError
instead of a plain bool. It allows to make -passes/aa-pipeline parsing
errors context-specific and thus less confusing.
TODO: ideally we should also make suggestions for misspelled pass names,
but that requires some extensions to PassBuilder.
Reviewed By: philip.pfaffe, chandlerc
Differential Revision: https://reviews.llvm.org/D53246
llvm-svn: 344685
Recommitting https://reviews.llvm.org/rL344544 after fixing undefined behavior
from left-shifting a negative value. Original commit message:
This support is slightly different then the X86_64 implementation in that calls
to __morestack don't need to get rewritten to calls to __moresatck_non_split
when a split-stack caller calls a non-split-stack callee. Instead the size of
the stack frame requested by the caller is adjusted prior to the call to
__morestack. The size the stack-frame will be adjusted by is tune-able through a
new --split-stack-adjust-size option.
llvm-svn: 344622
This reverts commit https://reviews.llvm.org/rL344544, which causes failures on
a undefined behaviour sanitizer bot -->
lld/ELF/Arch/PPC64.cpp:849:35: runtime error: left shift of negative value -1
llvm-svn: 344551
This support is slightly different then the X86_64 implementation in that calls
to __morestack don't need to get rewritten to calls to __moresatck_non_split
when a split-stack caller calls a non-split-stack callee. Instead the size of
the stack frame requested by the caller is adjusted prior to the call to
__morestack. The size the stack-frame will be adjusted by is tune-able through a
new --split-stack-adjust-size option.
Differential Revision: https://reviews.llvm.org/D52099
llvm-svn: 344544
This is https://bugs.llvm.org/show_bug.cgi?id=39289.
Currently both gold and bfd report errors about invalid options values
even with -v/-versions. But LLD does not.
This makes complicated to check the options available when LLD is used.
Patch makes LLD behavior to be consistent with GNU linkers.
Differential revision: https://reviews.llvm.org/D53278
llvm-svn: 344514
`Type` parameter was used only to check for TLS attribute mismatch,
but we can do that when we actually replace symbols, so we don't need
to type as an argument. This change should simplify the interface of
the symbol table a bit.
llvm-svn: 344394
This a resubmission of a patch which was previously reverted
due to breaking several lld tests. The issues causing those
failures have been fixed, so the patch is now resubmitted.
---Original Commit Message---
While it doesn't make a *ton* of sense for POSIX paths to be
in PDBs, it's possible to occur in real scenarios involving
cross compilation.
The tools need to be able to handle this, because certain types
of debugging scenarios are possible without a running process
and so don't necessarily require you to be on a Windows system.
These include post-mortem debugging and binary forensics (e.g.
using a debugger to disassemble functions and examine symbols
without running the process).
There's changes in clang, LLD, and lldb in this patch. After
this the cross-platform disassembly and source-list tests pass
on Linux.
Furthermore, the behavior of LLD can now be summarized by a much
simpler rule than before: Unless you specify /pdbsourcepath and
/pdbaltpath, the PDB ends up with paths that are valid within
the context of the machine that the link is performed on.
Differential Revision: https://reviews.llvm.org/D53149
llvm-svn: 344377
If you have the string /usr/bin, prior to this patch it would not
be quoted by our YAML serializer. But a string like C:\src would
be, due to the presence of a backslash. This makes the quoting
rules of basically every single file path different depending on
the path syntax (posix vs. Windows).
While technically not required by the YAML specification to quote
forward slashes, when the behavior of paths is inconsistent it
makes it difficult to portably write FileCheck lines that will
work with either kind of path.
Differential Revision: https://reviews.llvm.org/D53169
llvm-svn: 344359
This reverts commit b86c16ad8c97dadc1f529da72a5bb74e9eaed344.
This is being reverted because I forgot to write a useful
commit message, so I'm going to resubmit it with an actual
commit message.
llvm-svn: 344358
Android uses a compressed relocation format, which means the size of the
relocation section isn't predictable based on the number of relocations,
and can vary if the layout changes in any way. To deal with this, the
linker normally runs multiple passes until the layout converges.
The layout should converge if the size of the compressed
relocation section increases monotonically: if the size of an encoded
offset increases by one byte, the larget value which can be encoded is
multiplied by 128, so the representable offsets grow much faster than
the size of the section itself.
The problem here is that there is no code to ensure the size of the
section doesn't decrease. If the size of the relocation section
decreases, the relative offsets can increase due to alignment
restrictions, so that can force the size of the relocation section to
increase again. The end result is an infinite loop; the loop gets cut
off after 10 iterations with the message "thunk creation not
converged".
To avoid this issue, this patch adds padding to the end of the
relocation section if its size would decrease. The extra
padding is harmless because of the way the format is defined:
decoding stops after it reaches the number of relocations specified
in the section's header.
Differential Revision: https://reviews.llvm.org/D53003
llvm-svn: 344300
This was originally causing some test failures on non-Windows
platforms, which required fixes in the compiler and linker. After
those fixes, however, other tests started failing. Reverting
temporarily until I can address everything.
llvm-svn: 344279
While it doesn't make a *ton* of sense for POSIX paths to be
in PDBs, it's possible to occur in real scenarios involving
cross compilation.
The tools need to be able to handle this, because certain types
of debugging scenarios are possible without a running process
and so don't necessarily require you to be on a Windows system.
These include post-mortem debugging and binary forensics (e.g.
using a debugger to disassemble functions and examine symbols
without running the process).
There's changes in clang, LLD, and lldb in this patch. After
this the cross-platform disassembly and source-list tests pass
on Linux.
Furthermore, the behavior of LLD can now be summarized by a much
simpler rule than before: Unless you specify /pdbsourcepath and
/pdbaltpath, the PDB ends up with paths that are valid within
the context of the machine that the link is performed on.
Differential Revision: https://reviews.llvm.org/D53149
llvm-svn: 344269
When these are accessed with load/store instructions on ARM64,
it becomes strictly necessary to have them properly aligned.
This fixes PR39228.
Differential Revision: https://reviews.llvm.org/D53128
llvm-svn: 344264
This is https://bugs.llvm.org/show_bug.cgi?id=37538,
Currently, LLD may set both sh_link and sh_info for
.rela.plt section to zero when we have only .rela.iplt section part used.
ELF spec (https://docs.oracle.com/cd/E19683-01/816-1386/chapter6-94076/index.html)
says that for SHT_REL and SHT_RELA, sh_link references the associated symbol table
and sh_info the "section to which the relocation applies."
When we set the sh_link field, for the regular case we use the .dynsym index.
For .rela.iplt sections, it is unclear what is the associated symbol table,
because R_*_RELATIVE relocations do not use symbol names and we might have no
.dynsym section at all so this patch uses .symtab section index.
Differential revision: https://reviews.llvm.org/D52830
llvm-svn: 344226
Summary:
Add a condition UnresolvedPolicy::Ignore to elf::warnUnorderedSymbol to suppress Sym->isUndefined() warnings from both
1) --symbol-ordering-file=
2) .llvm.call-graph-profile
If --unresolved-symbols=ignore-all is used,
no "undefined symbol" error/warning is emitted. It makes sense to not warn unorderable symbols.
Otherwise,
If an executable is linked, the default policy UnresolvedPolicy::ErrorOrWarn will issue a "undefined symbol" error. The unorderable symbol warning is redundant.
If a shared object is linked, it is possible that only part of object files are used and some symbols are left undefined. The warning is not very necessary.
In particular for .llvm.call-graph-profile, when linking a shared object, a call graph profile may contain undefined symbols. This case generated a warning before but it will be suppressed by this patch.
Reviewers: ruiu, davidxl, espindola
Reviewed By: ruiu
Subscribers: grimar, emaste, arichardson, llvm-commits
Differential Revision: https://reviews.llvm.org/D53044
llvm-svn: 344195
This allows using #pragma comment(lib, "foo") in MinGW built code,
if built with -fms-extensions. (This works for system libraries and
static libraries only, as it doesn't try to look for .dll.a. As
ld.bfd doesn't support embedded defaultlib directives, this isn't
in widespread use among mingw users.)
Differential Revision: https://reviews.llvm.org/D53017
llvm-svn: 344124
This is necessary for handling defaultlib directives embedded in
object files, unless they use an absolute path.
Differential Revision: https://reviews.llvm.org/D53015
llvm-svn: 344123
Summary: Before, OptTable::PrintHelp append "[options] <inputs>" to its parameter `Help`. It is more flexible to change its semantic to `Usage` and let user customize the usage line.
Reviewers: rupprecht, ruiu, espindola
Reviewed By: rupprecht
Subscribers: emaste, sbc100, arichardson, aheejin, llvm-commits
Differential Revision: https://reviews.llvm.org/D53054
llvm-svn: 344099
Previously, we cast a pointer to Elf{32,64}_Chdr like this
auto *Hdr = reinterpret_cast<const ELF64_Chdr>(Ptr);
and read from its members like this
read32(&Hdr->ch_size);
I was thinking that this does not violate alignment requirement,
since &Hdr->ch_size doesn't really access memory, but seems like
it is a violation in terms of C++ spec (?)
In this patch, I use a different struct that allows unaligned access.
llvm-svn: 344083
`SymbolTable` is a singleton class and is a global variable for the
unique instance, so we can always refer the symtab by `Symtab->`.
However, we don't need to use the global varaible from member functions
of SymbolTable class.
llvm-svn: 344075
/pdbsourcepath: was added in https://reviews.llvm.org/D48882 to make it
possible to have relative paths in the debug info that clang-cl writes.
lld-link then makes the paths absolute at link time, which debuggers require.
This way, clang-cl's output is independent of the absolute path of the build
directory, which is useful for cacheability in distcc-like systems.
This patch extends /pdbsourcepath: (if passed) to also be used for:
1. The "cwd" stored in the env block in the pdb is /pdbsourcepath: if present
2. The "exe" stored in the env block in the pdb is made absolute relative
to /pdbsourcepath: instead of the cwd
3. The "pdb" stored in the env block in the pdb is made absolute relative
to /pdbsourcepath: instead of the cwd
4. For making absolute paths to .obj files referenced from the pdb
/pdbsourcepath: is now useful in three scenarios (the first one already working
before this change):
1. When building with full debug info, passing the real build dir to
/pdbsourcepath: allows having clang-cl's output to be independent
of the build directory path. This patch effectively doesn't change
behavior for this use case (assuming the cwd is the build dir).
2. When building without compile-time debug info but linking with /debug,
a fake fixed /pdbsourcepath: can be passed to get symbolized stacks
while making the pdb and exe independent of the current build dir.
For this two work, lld-link needs to be invoked with relative paths for
the lld-link invocation itself (for "exe"), for the pdb output name, the exe
output name (for "pdb"), and the obj input files, and no absolute path
must appear on the link command (for "cmd" in the pdb's env block).
Since no full debug info is present, it doesn't matter that the absolute
path doesn't exist on disk -- we only get symbols in stacks.
3. When building production builds with full debug info that don't have
local changes, and that get source indexed and their pdbs get uploaded
to a symbol server. /pdbsourcepath: again makes the build output independent
of the current directory, and the fixed path passed to /pdbsourcepath: can
be given the source indexing transform so that it gets mapped to a
repository path. This has the same requirements as 2.
This patch also makes it possible to create PDB files containing Windows-style
absolute paths when cross-compiling on a POSIX system.
Differential Revision: https://reviews.llvm.org/D53021
llvm-svn: 344061
Previously, we uncompress all compressed sections before doing anything.
That works, and that is conceptually simple, but that could results in
a waste of CPU time and memory if uncompressed sections are then
discarded or just copied to the output buffer.
In particular, if .debug_gnu_pub{names,types} are compressed and if no
-gdb-index option is given, we wasted CPU and memory because we
uncompress them into newly allocated bufers and then memcpy the buffers
to the output buffer. That temporary buffer was redundant.
This patch changes how to uncompress sections. Now, compressed sections
are uncompressed lazily. To do that, `Data` member of `InputSectionBase`
is now hidden from outside, and `data()` accessor automatically expands
an compressed buffer if necessary.
If no one calls `data()`, then `writeTo()` directly uncompresses
compressed data into the output buffer. That eliminates the redundant
memory allocation and redundant memcpy.
This patch significantly reduces memory consumption (20 GiB max RSS to
15 Gib) for an executable whose .debug_gnu_pub{names,types} are in total
5 GiB in an uncompressed form.
Differential Revision: https://reviews.llvm.org/D52917
llvm-svn: 343979
This matches the output of binutils' nm and ensures that any scripts
or tools that use nm and expect empty output in case there no symbols
don't break.
Differential Revision: https://reviews.llvm.org/D52943
llvm-svn: 343887
ld.bfd doesn't do any inference of subsystem; unless the windows
subsystem is specified, the console subsystem is used.
For the console subsystem, the entry point is called mainCRTStartup,
regardless of whether the the user code entry point is main or wmain.
The same goes for the windows subsystem, where the entry point always
is WinMainCRTStartup, for both WinMain and wWinMain in user code.
One detail that we don't emulate, is that if the inferred entry point
is undefined, ld.bfd silently just sets the entry point to the start
of the image. And if an explicit entry point is set, but it is
undefined, the link still succeeds but the linker warns about the
entry point not being found.
Differential Revision: https://reviews.llvm.org/D52931
llvm-svn: 343879
For certain cases of inline functions written to comdat sections,
GCC 5.x produces a weak symbol in addition, which would end up
undefined in some cases.
This no longer seems to happen with GCC 6.x or newer though.
Differential Revision: https://reviews.llvm.org/D52602
llvm-svn: 343877
(patch by Benoit Rousseau)
This patch fixes a bug where the global variable initializers were sometimes not invoked in the correct order when it involved a C++ template instantiation.
Differential Revision: https://reviews.llvm.org/D52749
llvm-svn: 343847
The GOT is referenced through the symbol _GLOBAL_OFFSET_TABLE_ .
The relocation added calculates the offset into the global offset table for
the entry of a symbol. In order to get the correct TargetVA I needed to
create an new relocation expression, HEXAGON_GOT. It does
Sym.getGotVA() - In.GotPlt->getVA().
Differential Revision: https://reviews.llvm.org/D52744
llvm-svn: 343784
r320770 made LLD handle invalid DSOs where local symbols were found in
the global part of the symbol table. Unfortunately, it didn't handle the
case where those local symbols were also undefined, and r326242 exposed
an assertion failure in that case. Just warn on that case instead of
crashing, by moving the local binding check before the undefined symbol
addition.
The input file for the test is crafted by hand, since I don't know of
any tool that would produce such a broken DSO. I also don't understand
what it even means for a symbol to be undefined but have STB_LOCAL
binding - I don't think that combination makes any sense - but we have
found broken DSOs of this nature that we were linking against. I've
included detailed instructions on how to produce the DSO in the test.
Differential Revision: https://reviews.llvm.org/D52815
llvm-svn: 343745
This patch splits ThunkCreator::mergeThunks into two smaller functions.
Also adds blank lines to various places so that the code doesn't look
too dense.
llvm-svn: 343732
A test verifying that toc restores are properly inserted following recursive
calls, as well as briefly describing why they are needed.
Differential Revision: https://reviews.llvm.org/D52564
llvm-svn: 343729
When GNU tools create a weak alias, they produce a strong symbol
named .weak.<weaksymbol>.<relatedstrongsymbol>.
GNU ld allows many such weak alternatives for the same weak symbol, and
the linker picks the first one encountered.
This can't be reproduced by assembling from .s files, since llvm-mc
produces symbols named .weak.<weaksymbol>.default in these cases.
Differential Revision: https://reviews.llvm.org/D52601
llvm-svn: 343704
Three related changes:
1. link.exe uses the presence of main and wmain to decide if it should call
mainCRTStartup or wmainCRTStartup, even if /nodefaultlib is passed. For
compatibility, remove FindMain logic.
2. Default to the non-wide entrypoint if main is not found. This has two effects:
2a. In normal links, lld-link now prints
lld-link: error: undefined symbol: _main
>>> referenced by f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:78
>>> libcmt.lib(exe_main.obj):("int __cdecl invoke_main(void)" (?invoke_main@@YAHXZ))
>>> referenced by f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:283
>>> libcmt.lib(exe_main.obj):("int __cdecl __scrt_common_main_seh(void)" (?__scrt_common_main_seh@@YAHXZ))
instead of
lld-link: error: entry point must be defined
This is arguably a better error message, since it now mentions that _main is
missing. (This matches link.exe's diagnostic in this case.)
2b. With /nodefautlib, we now default to mainCRTStartup if no main() is
present, again matching link.exe. This makes r337407 obsolete.
This means if you have a cc file containing both mainCRTStartup and
wmainCRTStartup and you pass /nodefaultlib /subsystem:console, lld-link will
now call mainCRTStartup, matching link.exe
3. Print a warning if both main and wmain are present, similar to link.exe's
LNK4067.
Differential Revision: https://reviews.llvm.org/D52832
llvm-svn: 343698
This stops testing the value of .rela.plt section offset.
Also makes _start global to eliminate
'cannot find entry symbol _start' warning.
llvm-svn: 343669
This is the fix for
"Bug 39104 - LLD links incorrect ELF executable if version script contains "local: *;"
(https://bugs.llvm.org/show_bug.cgi?id=39104).
The issue happens when we have non-PIC program call to function in a shared library.
(for example, the PR above has R_X86_64_PC32 relocation against __libc_start_main)
LLD converts symbol to Defined in that case with the use of replaceWithDefined()
The issue is that after above we create a broken relocation because do not
include the symbol into .dynsym.
That happens when the version script is used because we treat the symbol as
STB_LOCAL if the following condition match:
VersionId == VER_NDX_LOCAL && isDefined() and do not include it to
.dynsym because of that. Patch fixes the issue.
Differential revision: https://reviews.llvm.org/D52724
llvm-svn: 343668
Imagine we have the following code:
int foo();
int main() { return foo(); }
It will crash if you try to compile it with
`clang -O0 -gdwarf-5 test.cpp -o test -g -fuse-ld=lld`
The crash happens inside the LLVM DWARF parser because LLD does not provide
the .debug_line_str section. At the same time for correct parsing and reporting,
we anyways need to provide this section from our side.
The patch fixes the issue.
llvm-svn: 343667
Summary:
This patch adds a new flag, --warn-ifunc-textrel, to work around a glibc bug. When a code with ifunc symbols is used to produce an object file with text relocations, lld always succeeds. However, if that object file is linked using an old version of glibc, the resultant binary just crashes with segmentation fault when it is run (The bug is going to be corrected as of glibc 2.19).
Since there is no way to tell beforehand what library the object file will be linked against in the future, there does not seem to be a fool-proof way for lld to give an error only in cases where the binary will crash. So, with this change (dated 2018-09-25), lld starts to give a warning, contingent on a new command line flag that does not have a gnu counter part. The default value for --warn-ifunc-textrel is false, so lld behaviour will not change unless the user explicitly asks lld to give a warning. Users that link with a glibc library with version 2.19 or newer, or does not use ifunc symbols, or does not generate object files with text relocations do not need to take any action. Other users may consider to start passing warn-ifunc-textrel to lld to get early warnings.
Reviewers: ruiu, espindola
Reviewed By: ruiu
Subscribers: grimar, MaskRay, markj, emaste, arichardson, llvm-commits
Differential Revision: https://reviews.llvm.org/D52430
llvm-svn: 343628
llvm rL343594: [ARM] Emmit data symbol
for constant pool data fixed a bug that ommited
required data symbols.
Such change breaked a test case in lld:
test/ELF/arm-thunk-largesection.s
llvm-svn: 343604
This uses the call graph profile embedded in the object files to construct the call graph.
This is read from a SHT_LLVM_CALL_GRAPH_PROFILE (0x6fff4c02) section as (uint32_t, uint32_t, uint64_t) tuples as (from symbol index, to symbol index, weight).
Differential Revision: https://reviews.llvm.org/D45850
llvm-svn: 343552
When GCC produces a jump table as part of a comdat function, the
jump table itself is produced as plain non-comdat rdata section. When
linked with ld.bfd, all of those rdata sections are kept, with
relocations unchanged in the sections that refer to discarded comdat
sections.
This has been observed with at least GCC 5.x and 7.x.
Differential Revision: https://reviews.llvm.org/D52600
llvm-svn: 343422
With LTO when and undefined function (with a known signature)
in replaced by a defined bitcode function we were loosing the
signature information (since bitcode functions don't have
signatures).
With this change we preserve the original signature from the
undefined function and verify that the post LTO compiled
function has the correct signature.
This change improves the error handling in the case where
there is a signature mismatch with a function defined in
a bitcode file.
Differential Revision: https://reviews.llvm.org/D50721
llvm-svn: 343340
In a very recent change I introduced a --no-export-default flag
but after conferring with others it seems that this feature already
exists in gnu GNU ld and lld in the form the --export-dynamic flag
which is off by default.
This change replaces export-default with export-dynamic and also
changes the default to match the traditional linker behaviour.
Now, by default, only the entry point is exported. If other symbols
are required by the embedder then --export-dynamic or --export can
be used to export all visibility hidden symbols or individual
symbols respectively.
This change touches a lot of tests that were relying on symbols
being exported by default. I imagine it will also effect many
users but do think the change is worth it match of the traditional
behaviour and flag names.
Differential Revision: https://reviews.llvm.org/D52587
llvm-svn: 343265
Add REQUIRES: x86 to pdb-debug-f.s as this is causing the Arm and
AArch64 buildbots to fail as they do not have the x86 backend.
Differential Revision: https://reviews.llvm.org/D52606
llvm-svn: 343196
Summary: The convenience wrapper in STLExtras is available since rL342102.
Reviewers: ruiu, espindola
Subscribers: emaste, arichardson, mgrang, llvm-commits
Differential Revision: https://reviews.llvm.org/D52569
llvm-svn: 343146
Summary:
lld already gives later -z options precedence in getZFlag().
This matches the behavior of ld.bfd and ld.gold, where later options
override earlier ones. (I tested with -z max-page-size and -z stack-size.)
Reviewers: ruiu, espindola, grimar
Reviewed By: ruiu, grimar
Subscribers: grimar, emaste, arichardson, llvm-commits
Differential Revision: https://reviews.llvm.org/D52526
llvm-svn: 343145
Summary:
An AArch64 LE relocation is a positive ("variant 1") offset. This
relocation is used to write the upper 12 bits of a 24-bit offset into an
add instruction:
add x0, x0, :tprel_hi12:v1
The comment in the ARM docs for R_AARCH64_TLSLE_ADD_TPREL_HI12 is:
"Set an ADD immediate field to bits [23:12] of X; check 0 <= X < 2^24."
Reviewers: javed.absar, espindola, ruiu, peter.smith, zatrazz
Reviewed By: ruiu
Subscribers: emaste, arichardson, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D52525
llvm-svn: 343144
This is https://bugs.llvm.org//show_bug.cgi?id=38919.
Currently, LLD may report "unsupported relocation target while parsing debug info"
when parsing the debug information.
At the same time LLD does that for zeroed R_X86_64_NONE relocations,
which obviously has "invalid" targets.
The nature of R_*_NONE relocation assumes them should be ignored.
This patch teaches LLD to stop reporting the debug information parsing errors for them.
Differential revision: https://reviews.llvm.org/D52408
llvm-svn: 343078
This involves adding more generic list of symbol suffixes/prefixes
to ignore for autoexport; adding a few other entries to these lists
as well from the corresponding lists in binutils.
Differential Revision: https://reviews.llvm.org/D52382
llvm-svn: 343070
Don't assume that the IAT chunk will be a DefinedImportData, it can
just as well be a DefinedRegular for gnu import libraries.
Differential Revision: https://reviews.llvm.org/D52381
llvm-svn: 343069
These option control weather or not symbols marked as visibility
default are exported in the output binary.
By default this is true, but emscripten prefers to control the
exported symbol list explicitly at link time and ignore the
symbol attributes.
Differential Revision: https://reviews.llvm.org/D52003
llvm-svn: 343034
When we write a struct to a mmap'ed buffer, we usually use
write16/32/64, but we didn't for VersionDefinitionSection, so
we needed to template that class.
llvm-svn: 343024
Previously, if you invoke lld's `main` more than once in the same process,
the second invocation could fail or produce a wrong result due to a stale
pointer values of the previous run.
Differential Revision: https://reviews.llvm.org/D52506
llvm-svn: 343009
This is a feature that MS link.exe lacks; it currently errors out on
such relocations, just like lld did before.
This allows linking clang.exe for ARM - practically, any image over
16 MB will likely run into the issue.
Differential Revision: https://reviews.llvm.org/D52156
llvm-svn: 342962
George Rimar