This is https://bugs.llvm.org//show_bug.cgi?id=38750.
If script references empty sections in LOADADDR/ADDR commands
.empty : { *(.empty ) }
.text : AT(LOADADDR (.empty) + SIZEOF (.empty)) { *(.text) }
then an empty section will be removed and LOADADDR/ADDR will evaluate to null.
It is not that user may expect from using of the generic script, what is a common case.
Differential revision: https://reviews.llvm.org/D54621
llvm-svn: 359279
Summary:
We use `uint32_t SectionBase::Alignment` and `uint32_t
PhdrEntry::p_align` despite alignments being 64 bits in ELF64.
Fix the std::max template arguments accordingly.
The currently 160-byte InputSection will become 168 bytes if we make SectionBase::Alignment uint64_t.
Differential Revision: https://reviews.llvm.org/D61171
llvm-svn: 359268
The code we generate for applying data relocations at runtime omitted
the symbols with GOT entries.
Also refactor the code to reduce duplication.
Differential Revision: https://reviews.llvm.org/D61111
llvm-svn: 359207
This removes one more binary object from the inputs and fixes the
test case description.
Previously it said that:
"symbol-index.elf has incorrect type of .symtab section.
There is no symbol bodies because of that and any symbol index becomes incorrect."
But the real reason of the failture was not the incorrect type of a symbol table,
but invalid index of the symbol used in a relocation, what happened because
previous test tried to read .symtab as a SHT_RELA section.
llvm-svn: 359197
r191276 added this to old LLD, but it never made it to new LLD -- except
that the flag was in Options.td, so it was silently ignored. I figured
it should be easy to implement, so I did that instead of removing the
flags from Options.td.
I then discovered that link.exe also supports comma-separated lists of
'cd' and 'net', which made the parsing code a bit annoying.
The Alias technique in Options.td is to get nice help output.
Differential Revision: https://reviews.llvm.org/D61067
llvm-svn: 359192
For well-known type IDs, include the name of the type.
To not duplicate the ID->name map, make llvm-readobj call this new
function as well. It has slightly different output, so this also
requires updating a few tests.
Differential Revision: https://reviews.llvm.org/D61086
llvm-svn: 359153
Fixes small typos in WebAssembly documentation. I first noticed the
sub-heading "Bahavior", and then decided to review the whole file.
Patch by Christoph Siedentop!
Differential Revision: https://reviews.llvm.org/D60987
llvm-svn: 359103
Summary:
We don't take localentry offset into account, and thus may fail to
create a long branch when the gap is just a few bytes smaller than 2^25.
relocation R_PPC64_REL24 out of range: 33554432 is not in [-33554432, 33554431]
relocation R_PPC64_REL24 out of range: 33554436 is not in [-33554432, 33554431]
Fix that by adding the offset to the symbol VA.
Differential Revision: https://reviews.llvm.org/D61058
llvm-svn: 359094
dynamic-section-sh_size.elf was introduced in D25090.
Now it is possible to use yaml2obj instead.
That is what this patch does.
Also I added one more case of a possibly broken .dynamic
section just in case.
llvm-svn: 358990
file-class.a was used to diagnose the "corrupted ELF file: invalid file class"
error when the object was fetched from the archive.
file-class.a contained an object of 16 bytes size. I replaced it with
an echo call (because it is impossible to use yaml2obj for that, and I am
not sure it is worth to support), and also increased its size to 18 bytes.
That allowed to also test a case when such object is a regular input and not an
archive member (we have a bit different logic for these cases).
llvm-svn: 358985
This fixes an issue where a symbol only section at the start of a
PT_LOAD segment, causes incorrect alignment of the file offset for the
start of the segment which results in the output of an invalid ELF.
SHT_PROGBITS was the default output section type in the past.
Differential Revision: https://reviews.llvm.org/D60131
llvm-svn: 358981
The following options: /pdb, /out or /implib now emit in the repro.tar/response.txt only a filename stripped from its path, to avoid non-existent paths on the reproducer's machine.
Differential Revision: https://reviews.llvm.org/D59530
llvm-svn: 358980
This patch changes the behaviour of findOrphanPos to only consider live
sections when placing orphan sections. This used to be how it behaved in
the past.
Differential Revision: https://reviews.llvm.org/D60273
llvm-svn: 358979
Various improvement:
Some offsets in disassembly are incorrect after several layout adjustment. Fix them.
llvm-objdump -D should not be used. -D dumps unrelated non-text sections. Replace them with llvm-objdump -d, llvm-readelf -x, etc
Many llvm-objdump -d tests use {{.*}} . Add the option --no-show-raw-insn to avoid check hex bytes.
ppc64-long-branch.s does not need a shared object. Delete it.
Make ppc64-ifunc.s check 2 ifuncs.
Reviewers: ruiu, espindola
Subscribers: emaste, nemanjai, arichardson, kbarton, jsji, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60998
llvm-svn: 358975
It was initially introduced in D25229 to report the "zero option descriptor size"
error message. In following commits it was broken and did not report this
error anymore. I think that happened because elf object was a result of fuzzing
and it was broken in many ways.
This patch converts this test to a YAML, removes a binary and hence fixes the
original intention.
llvm-svn: 358972
rL358960 "[llvm-mc] - Properly set the the address align field of the compressed sections."
changed the sh_addralign field of the "zlib" compressed debug sections.
llvm-svn: 358961
Make some small adjustment while touching the code: make parameters
const, use less_first(), etc.
Differential Revision: https://reviews.llvm.org/D60989
llvm-svn: 358943
We can't (currently) meaningfully resolve certain types of relocations
against undefined data symbols. Previously when `--allow-undefined` was
used we were treating such relocation much like weak data symbols and
simply inserting zeros. This change turns such use cases in to an
error.
This means that `--allow-undefined` is no longer effective for data
symbols.
Fixes https://bugs.llvm.org/show_bug.cgi?id=40364
Differential Revision: https://reviews.llvm.org/D60882
llvm-svn: 358899
We were incorrectly used the symbol table version of the function rather
than the object-local version when checking the existing relocation
value.
This was causing erroneous warnings for comat symbols defined in
multiple object.s
Fixes: https://bugs.llvm.org/show_bug.cgi?id=40503
Differential Revision: https://reviews.llvm.org/D60928
llvm-svn: 358871
Summary:
Fixes PR35242. A simplified reproduce:
thread_local int i; int f() { return i; }
% {g++,clang++} -fPIC -shared -ftls-model=local-dynamic -fuse-ld=lld a.cc
ld.lld: error: can't create dynamic relocation R_X86_64_DTPOFF32 against symbol: i in readonly segment; recompile object files with -fPIC or pass '-Wl,-z,notext' to allow text relocations in the output
In isStaticLinkTimeConstant(), Syn.IsPreemptible is true, so it is not
seen as a constant. The error is then issued in processRelocAux().
A symbol of the local-dynamic TLS model cannot be preempted but it can
preempt symbols of the global-dynamic TLS model in other DSOs.
So it makes some sense that the variable is not static.
This patch fixes the linking error by changing getRelExpr() on
R_386_TLS_LDO_32 and R_X86_64_DTPOFF{32,64} from R_ABS to R_DTPREL.
R_PPC64_DTPREL_* and R_MIPS_TLS_DTPREL_* need similar fixes, but they are not handled in this patch.
As a bonus, we use `if (Expr == R_ABS && !Config->Shared)` to find
ld-to-le opportunities. R_ABS is overloaded here for such STT_TLS symbols.
A dedicated R_DTPREL is clearer.
Differential Revision: https://reviews.llvm.org/D60945
llvm-svn: 358870
Summary:
This relocation type is used by R_386_TLS_GD. Its formula is the same as
R_GOTPLT (e.g R_X86_64_GOT{32,64} R_386_TLS_GOTIE). Rename it to be clearer.
Differential Revision: https://reviews.llvm.org/D60941
llvm-svn: 358868
Summary:
The DataCount section is necessary for the bulk memory operations
memory.init and data.drop to validate, but it is not recognized by
engines that do not support bulk memory, so emit the section only if
bulk-memory is enabled.
Reviewers: aheejin, dschuff, sbc100
Subscribers: jgravelle-google, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60637
llvm-svn: 358798
Summary:
This assumes all symbols are <4GB long, so we can store them as a 32-bit
integer. This reorders the fields so the length appears first, packing
with the other bitfield data in the base Symbol object.
This saved 70MB / 3.60% of heap allocations when linking
browser_tests.exe with no PDB. It's not much as a percentage, but worth
doing. I didn't do performance measurements, I don't think it will be
measurable in time.
Reviewers: ruiu, inglorion, amccarth, aganea
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60297
llvm-svn: 358794
Another attempt to land the changes in debug line header to prevent duplicate
files in Dwarf 5. I rolled back my previous commit because of a mistake in
generating the object file in a test. Meanwhile, I addressed some offline
comments and changed the implementation; the largest difference is that
MCDwarfLineTableHeader does not keep DwarfVersion but gets it as a parameter. I
also merged the patch to fix two lld tests that will strt to fail into this
patch.
Original Commit:
https://reviews.llvm.org/D59515
Original Message:
Motivation: In previous dwarf versions, file name indexes started from 1, and
the primary source file was not explicit. Dwarf 5 standard (6.2.4) prescribes
the primary source file to be explicitly given an entry with an index number 0.
The current implementation honors the specification by just duplicating the
main source file, once with index number 0, and later maybe with another
index number. While this is compliant with the letter of the standard, the
duplication causes problems for consumers of this information such as lldb.
(Some files are duplicated, where only some of them have a line table although
all refer to the same file)
With this change, dwarf 5 debug line section files always start from 0, and
the zeroth entry is not duplicated whenever possible. This requires different
handling of dwarf 4 and dwarf 5 during generation (e.g. when a function returns
an index zero for a file name, it signals an error in dwarf 4, but not in dwarf
5) However, I think the minor complication is worth it, because it enables all
consumers (lldb, gdb, dwarfdump, objdump, and so on) to treat all files in the
file name list homogenously.
llvm-svn: 358732
This is https://bugs.llvm.org//show_bug.cgi?id=39857.
I added the comment with much more details to the bug page,
the short version is below.
The following script and code demonstrates the issue:
aliasto__text = __text;
SECTIONS {
.text 0x1000 : { __text = . ; *(.text) }
}
...
call aliasto__text
LLD fails with "cannot refer to absolute symbol: aliasto__text" error.
It happens because at the moment of scanning the relocations
we do not yet assign the correct/final/any section value for the symbol aliasto__text.
I made a change to Relocations.cpp to fix that.
Also, I had to remove the symbol-location.s test case completely, because now it does not
trigger any error. Since now all linker scripts symbols are resolved to constants, no
errors can be triggered at all it seems. I checked that it is consistent with the behavior
of bfd and gold (they do not trigger errors for the case from symbol-location.s), so it should
be OK. I.e. at least it is probably not the best possible, but natural behavior we obtained.
Differential revision: https://reviews.llvm.org/D55423
llvm-svn: 358652
Summary:
If the output section contains only symbol assignments, we copy flags
from the previous sections. Don't set SHF_ALLOC if NonAlloc is true.
We also have to change the type from SHT_NOBITS to SHT_PROGBITS.
In ld.bfd, bfd_elf_get_default_section_type maps non-alloctable sections to SHT_PROGBITS.
Non-alloctable SHT_NOBITS sections do not make sense.
Fixes PR38626
Differential Revision: https://reviews.llvm.org/D59986
llvm-svn: 358650
This generalizes code and also fixes the broken behavior shown in
one of our test cases for some targets, like x86-64.
The issue occurs when the forward declarations are used in the script.
One of the samples is:
SECTIONS {
foo = ADDR(.text) - ABSOLUTE(ADDR(.text));
};
In that case, we have a broken output when output target does
not use thunks. That happens because thunks creating code
(called from maybeAddThunks)
calls Script->assignAddresses() at least one more time,
what fixups the values. As a result final symbols values can
be different on AArch64 and x86, for example.
In this patch, I generalize and rename maybeAddThunks to
finalizeAddressDependentContent and now it is used and called
by all targets.
Differential revision: https://reviews.llvm.org/D55550
llvm-svn: 358646
Summary:
We access Live and OutputOff (which may share the same memory location)
concurrently in 2 parallelForEachN loops. Separating them avoids subtle
data races like D41884/PR35788. This patch places Live and Hash
together.
2 reasons this is appealing:
1) Hash is immutable. Live is almost read-only - only written once in MarkLive.cpp where
Hash is not accessed
2) we already discard low bits of Hash to decide ShardID. It doesn't
matter much if we make 32-bit Hash to 31-bit.
For a huge internal clang -O3 executable (1.6GiB),
`Strings` in StringTableBuilder::finalizeStringTable contains at most 310253 elements.
The expected number of pair-wise collisions 2^(-31) * C(310253,2) ~= 22.41 is too small to have a negative impact on performance.
Actually, my benchmark shows there is actually a minor performance improvement.
Differential Revision: https://reviews.llvm.org/D60765
llvm-svn: 358645
Patch by Gabriel Smith.
The address for a section would be evaluated before the region was
switched to. Because of this, the position within the region would not
be updated. After the region is swapped to the dot would be set to the
out of date position within the region, undoing the section address
evaluation.
To fix this, the region is swapped to before the section's address is
evaluated. As part of the fallout of this, expandMemoryRegions needed
to be gated in setDot on the condition that the evaluated address is
less than the dot. This is for the case where sections are not listed
from lowest address to highest address.
Finally, a test for the case where sections are listed "out of order"
was added.
Differential Revision: https://reviews.llvm.org/D60744
llvm-svn: 358638
Patch by Nicholas Allegra.
The Mach-O writer calculates the size of load commands multiple times.
First, Util::assignAddressesToSections() (in MachONormalizedFileFromAtoms.cpp)
calculates the size using headerAndLoadCommandsSize() (in
MachONormalizedFileBinaryWriter.cpp), which creates a temporary
MachOFileLayout for the NormalizedFile, only to retrieve its
headerAndLoadCommandsSize. Later, writeBinary() (in
MachONormalizedFileBinaryWriter.cpp) creates a new layout and uses the offsets
from that layout to actually write out everything in the NormalizedFile.
But the NormalizedFile changes between the first computation and the second.
When Util::assignAddressesToSections is called, file.functionStarts is always
empty because Util::addFunctionStarts has not yet been called. Yet
MachOFileLayout decides whether to include a LC_FUNCTION_STARTS command based
on whether file.functionStarts is nonempty. Therefore, the initial computation
always omits it.
Because padding for the __TEXT segment (to make its size a multiple of the
page size) is added between the load commands and the first section, LLD still
generates a valid binary as long as the amount of padding happens to be large
enough to fit LC_FUNCTION_STARTS command, which it usually is.
However, it's easy to reproduce the issue by adding a section of a precise
size. Given foo.c:
__attribute__((section("__TEXT,__foo")))
char foo[0xd78] = {0};
Run:
clang -dynamiclib -o foo.dylib foo.c -fuse-ld=lld -install_name
/usr/lib/foo.dylib
otool -lvv foo.dylib
This should produce:
truncated or malformed object (offset field of section 1 in LC_SEGMENT_64
command 0 not past the headers of the file)
This commit:
- Changes MachOFileLayout to always assume LC_FUNCTION_STARTS is present for
the initial computation, as long as generating LC_FUNCTION_STARTS is
enabled. It would be slightly better to check whether there are actually
any functions, since no LC_FUNCTION_STARTS will be generated if not, but it
doesn't cause a problem if the initial computation is too high.
- Adds a test.
- Adds an assert in MachOFileLayout::writeSectionContent() that we are not
writing section content into the load commands region (which would happen
if the offset was calculated too low due to the initial load commands size
calculation being too low). Adds an assert in
MachOFileLayout::writeLoadCommands to validate a similar situation where
two size-of-load-commands computations are expected to be equivalent.
llvm-svn: 358545
With partitions, each partition should have the same build id. This means
that the build id needs to be only computed once, otherwise we will end up
with different build ids in each partition as a result of the file contents
changing. This change moves the computation of the build id into Writer so
that it only happens once.
Differential Revision: https://reviews.llvm.org/D60342
llvm-svn: 358536
George Rimar