When the data segment is the last segment, it is correct to leave
it unaligned. However, when the code segment is the last segment,
it should be aligned to the page boundary to avoid loading the
non-segment parts of the ELF file at the end of the file.
Differential Revision: https://reviews.llvm.org/D33630
llvm-svn: 309829
With fix for undefined weak symbols in executable.
Original commit message:
This is PR32112. Previously when we linked executable with
--unresolved-symbols=ignore-all and undefined symbols, like:
_start:
callq und@PLT
we did not create relocations, though it looks in that case
we should delegate handling of such symbols to runtime linker,
hence should emit them. Patch fixes that.
Differential revision: https://reviews.llvm.org/D35724
llvm-svn: 309796
We don't write any actual symbols to this stream yet, but for
now we just create the stream and hook it up to the appropriate
places and give it a valid header.
Differential Revision: https://reviews.llvm.org/D35290
llvm-svn: 309608
Before we were doing it with --export-dynamic. That seems incorrect.
The intention of --export-dynamic is to export symbols *defined* in
the executable.
llvm-svn: 309605
Previously we would crash when tried to ALIGN(0).
Patch uses value 1 instead in this case, that
looks to be consistent with GNU linkers
and reasonable and simple behavior itself.
Differential revision: https://reviews.llvm.org/D35942
llvm-svn: 309372
Summary:
MSVC link.exe records all external symbol names in the publics stream.
It provides similar functionality to an ELF .symtab.
Reviewers: zturner, ruiu
Subscribers: hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D35871
llvm-svn: 309303
This is PR32112. Previously when we linked executable with
--unresolved-symbols=ignore-all and undefined symbols, like:
_start:
callq und@PLT
we did not create relocations, though it looks in that case
we should delegate handling of such symbols to runtime linker,
hence should emit them. Patch fixes that.
Differential revision: https://reviews.llvm.org/D35724
llvm-svn: 309252
With this we only ask LTO to keep a C named section if there is a
__start_ or __end symbol.
This is not as strict as lld's --gc-sections, but is as good as we can
get without having a far more detailed ir summary.
llvm-svn: 309232
This patch fixes a small issue with respect to how memory region names
are parsed on output section descriptions. For example, consider:
.text : { *(.text) } > rom
That can also be written like:
.text : { *(.text) } >rom
The latter form is accepted by GNU LD and is fairly common.
Differential Revision: https://reviews.llvm.org/D35920
llvm-svn: 309191
Also handle overflow correctly in LDR/STR relocations. Even if the
offset range of a 8 byte LDR instruction is 15 bit (even if the immediate
itself is 12 bit) due to a 3 bit shift, only include up to 12 bits of offset
after doing the relocation, by limiting the range of the immediate by the
number of shifted bits.
Differential Revision: https://reviews.llvm.org/D35792
llvm-svn: 309175
Previously we handled this option implicitly, only
for infering unresolved symbols handling policy.
ld man says: "--noinhibit-exec Retain the executable
output file whenever it is still usable",
and we may want to handle other cases too.
Differential revision: https://reviews.llvm.org/D35793
llvm-svn: 309091
This is PR30422,
previously LLD did not render all option aliases in --help.
With this patch it will.
Differential revision: https://reviews.llvm.org/D35477
llvm-svn: 309089
The test used /manifestinput: without /manifest:embed, which isn't actually
supported. Just remove this part of the test for now; if it's important to
check this the llvm-readobj part should be extended to check this.
llvm-svn: 309002
Also emit an error if /manifestinput: is used without /manifest:embed.
Increases compatibility with link.exe
https://reviews.llvm.org/D35842
llvm-svn: 308998
Previously .init_array/.fini_array sections
were not unique and we had 3 .init_array sections +
3 .fini_array input sections passed to linker,
instead of 5 + 5.
Differential revision: https://reviews.llvm.org/D35552
llvm-svn: 308958
This is PR33714.
Previously for each input section offset of memory region
was incremented on a size of output section.
That resulted in a wrong error message saying about
overflow. Patch fixes that.
Differential revision: https://reviews.llvm.org/D35803
llvm-svn: 308955
The same adjustment is already done for the entry point in
Writer.cpp and for relocations that point to executable code
in Chunks.cpp.
Differential Revision: https://reviews.llvm.org/D35767
llvm-svn: 308953
We do this emitting a section for every function when LTO is used.
Fixes PR33888.
Differential Revision: https://reviews.llvm.org/D35809
llvm-svn: 308915
Eq helper allows to define `XXX` and `XXX=` options forms easily.
Patch adds testcases for few aliases.
Differential revision: https://reviews.llvm.org/D35619
llvm-svn: 308752
Also add the test cases for the addition and subtraction both for
the relative and absolute case.
Differential Revision: https://reviews.llvm.org/D35346
llvm-svn: 308692
We were not looking at Repl and so thinking there was no output
section associated with the merged symbol. Because of that it was
produced as absolute.
This was found by an internal round of testing.
llvm-svn: 308681
Summary:
If the linker is invoked with `--chroot /foo` and `/bar/baz.o`, it
tries to read the file from `/foo/bar/baz.o`. This feature is useful
when you are dealing with files created by the --reproduce option.
Reviewers: grimar
Subscribers: llvm-commits, emaste
Differential Revision: https://reviews.llvm.org/D35517
llvm-svn: 308646
Also extend the tests for IMAGE_REL_ARM64_PAGEOFFSET_12L to test
all 8/16/32/64 bit GPR and 8/16/32/64/128 SIMD/FP bit ldr/str variants,
and a ldr with an existing offset.
Differential revision: https://reviews.llvm.org/D35647
llvm-svn: 308631
This fixes cases on ARM64 when importing from more than one DLL,
in case the imports from the first DLL ended up unaligned.
When fixing up a IMAGE_REL_ARM64_PAGEOFFSET_12L, which shifts the
offset by the load/store size, check that the shift doesn't discard
any bits. (This would also detect if the import address chunks were
unaligned.)
Differential revision: https://reviews.llvm.org/D35640
llvm-svn: 308585
With that in place we can use lld's own infrastructure for the low
level detail of dwarf parsing.
With this we don't decompress sections twice, we don't scan all
realocations and even with this simplistic implementation linking
clang with gdb index goes from 34.09 seconds to 20.80 seconds.
llvm-svn: 308544
In addition this includes a change to prefer symbols with a default
version @@ over unversioned symbols.
Original commit message:
[ELF] - Handle symbols with default version early.
This fixes last testcase provided in PR28414.
In short issue is next: when we had X@@Version symbol in object A,
we did not resolve it to X early. Then when in another object B
we had reference to undefined X, symbol X from archive was fetched.
Since both archive and object A contains another symbol Z, duplicate
symbol definition was triggered as a result.
Correct behavior is to use X@@Version from object A instead and do not fetch
any symbols from archive.
Differential revision: https://reviews.llvm.org/D35059
llvm-svn: 308492
This test is folded into implib-name. Don't bother with the racy test.
The use of %T results in left-overs from previous tests which write out
the same import library as this test.
llvm-svn: 308409
Improve the link conformance for the import name embedded into the
import library. This requires the associated change to the LLVM portion
for the DEF file parser. The import file generation embeds a different
name based on whether the driver is invoked as "link" or "lib".
Furthermore, the LIBRARY keyword in the DEF file influences the import
name. The behaviour can be summarised according to the following table:
| LIBRARY w/ ext | LIBRARY w/o ext | no LIBRARY
-----+----------------+---------------------+------------------
LINK | {value} | {value}.{.dll/.exe} | {output name}
LIB | {value} | {value}.dll | {output name}.dll
llvm-svn: 308407
Noticed while testing for an out of tree target. There are probably more tests that should be so marked.
I'm not sure who owns these tests so I've added a few names I recognise from the recent history.
With advice from probinson, ruiu, rafael and dramatically improved by davidb. Thank you all!
Differential Revision: https://reviews.llvm.org/D34685
llvm-svn: 308335
DWARF debug sections can also contain relocations against symbols in
discared segments. LLD should accept such relocations.
Differential Revision: https://reviews.llvm.org/D35526
llvm-svn: 308315
Summary:
Object files compiled with /Zi emit type information into a type server
PDB. The .debug$S section will contain a single TypeServer2Record with
the absolute path and GUID of the type server. LLD needs to load the
type server PDB and merge all types and items it finds in it into the
destination PDB.
Depends on D35495
Reviewers: ruiu, inglorion
Subscribers: zturner, llvm-commits
Differential Revision: https://reviews.llvm.org/D35504
llvm-svn: 308235
Summary:
We were treating the GUIDs in TypeServer2Record as strings, and the
non-ASCII bytes in the GUID would not round-trip through YAML.
We already had the PDB_UniqueId type portably represent a Windows GUID,
but we need to hoist that up to the DebugInfo/CodeView library so that
we can use it in the TypeServer2Record as well as in PDB parsing code.
Reviewers: inglorion, amccarth
Subscribers: llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D35495
llvm-svn: 308234
Summary:
Instead of wiring these through the CVTypeVisitor interface, clients
should inspect the CVTypeArray before visiting it and potentially load
up the type server's TPI stream if they need it.
No tests relied on this functionality because LLD was the only client.
Reviewers: ruiu
Subscribers: mgorny, hiraditya, zturner, llvm-commits
Differential Revision: https://reviews.llvm.org/D35394
llvm-svn: 308212
This is PR33766.
-F name
--filter=name
When creating an ELF shared object, set the internal DT_FILTER field to the specified name. This tells the dynamic linker that the symbol table of the shared object which is being created should be used as a filter on the symbol table of the shared object name.
If you later link a program against this filter object, then, when you run the program, the dynamic linker will see the DT_FILTER field. The dynamic linker will resolve symbols according to the symbol table of the filter object as usual, but it will actually link to the definitions found in the shared object name. Thus the filter object can be used to select a subset of the symbols provided by the object name.
(https://linux.die.net/man/1/ld).
Shared Objects as Filters:
https://docs.oracle.com/cd/E19683-01/817-3677/chapter4-31738/index.html
Differential revision: https://reviews.llvm.org/D35352
llvm-svn: 308167
Previously we used precompiled objects in gdb-index.s and
debug-gnu-pubnames.s testcases. We can avoid that.
Differential revision: https://reviews.llvm.org/D35360
llvm-svn: 308005
In filling the .got sections, InputSection::OutSecOff was added twice
when finding the position to apply a relocation: first time in
InputSection::writeTo() and then in SectionBase::getOffset().
Differential revision: https://reviews.llvm.org/D34232
llvm-svn: 308003
This was previously erroring out if one of the dead symbols was a
TLS symbol and we were able to discard all TLS sections.
Differential Revision: https://reviews.llvm.org/D35397
llvm-svn: 307984
PT_TLS is a type of program header, so we wouldn't expect to see
one in an object file. This error should probably be referring to
the fact that we didn't see a section with the flag SHF_TLS, which
would normally cause us to create a PT_TLS program header.
Differential Revision: https://reviews.llvm.org/D35395
llvm-svn: 307983
Summary:
This would have caught the invalid object file I used in my test case in
r307726. The OOB was only caught by ASan later, which is slow and
doesn't work on some platforms. LLD should do some basic input
validation itself. This check isn't perfect, so relocations can reach
OOB by up to seven bytes, but it's better than what we had and probably
cheap.
Reviewers: ruiu
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D35371
llvm-svn: 307948
Summary:
This fixes type indices for SDK or CRT static archives. Previously we'd
try to look next to the archive object file path, which would not exist
on the local machine.
Also error out if we can't resolve a type server record. Hypothetically
we can recover from this error by discarding debug info for this object,
but that is not yet implemented.
Reviewers: ruiu, amccarth
Subscribers: aprantl, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D35369
llvm-svn: 307946
Patch removes restriction about moving location counter
backwards outside of output sections declarations.
That may be useful for some apps relying on such scripts,
known example is linux kernel.
Differential revision: https://reviews.llvm.org/D34977
llvm-svn: 307794
This fixes PR33712.
Imagine following script and code:
VER1 { global: foo; local: *; };
VER2 { global: foo; };
.global bar
bar:
.symver bar, foo@VER1
.global zed
zed:
.symver zed, foo@@VER2
We add foo@@VER2 as foo to symbol table, because have to resolve references to
foo for default symbols.
Later we are trying to assign symbol versions from script. For that we are searching for 'foo'
again. Here it is placed under VER1 and VER2 at the same time, we find it twice and trying to
set version again both times, hence LLD shows a warning.
Though sample code is correct: we have 2 different versions of foo.
Patch gives a symbol version extracted from name a priority over version set by script.
Differential revision: https://reviews.llvm.org/D35207
llvm-svn: 307792
When version script was used, binding opf undefined weak symbols sometimes
was calculated as STB_LOCAL, making them non-preemtible what
broke correct relocations handling logic for them.
Fixes PR33738.
Differential revision: https://reviews.llvm.org/D35263
llvm-svn: 307767
Revert "[PDB] Tweak bad type index error handling"
check-lld with asan detects use-after-poison.
This reverts commits r307733 and r307726.
llvm-svn: 307752
Translate invalid type indices to a sentinel value instead of skipping
the record. Skipping records isn't a good recovery method, because we
can skip a scope open or close record, which will confuse the scope
management code.
We currently have lots of invalid type indices on Microsoft-provided
standard libraries, because the LF_TYPESERVER2 records contain absolute
paths that are only valid on their build servers. Our type server
handlers need to look at other things (GUIDs) to find these type server
PDBs.
llvm-svn: 307726
It was intially implemented in D19517 but then broken.
Patch fixes PR33707, testcase is based on PR's case.
Differential revision: https://reviews.llvm.org/D35119
llvm-svn: 307652
This is enough to link a working hello world executable, with
a call to an imported function, a string constant passed to
the imported function, and loads from a global variable.
Differential Revision: https://reviews.llvm.org/D34964
llvm-svn: 307629
This is part of the continuing effort to increase parity between
LLD and MSVC PDBs. link still doesn't like our PDBs, so the most
obvious thing to check was whether adding an empty publics stream
would get it to do something else. It still fails in the same way
but at least this removes one more variable from the equation.
The next logical step would be to try creating an empty globals
stream.
Differential Revision: https://reviews.llvm.org/D35224
llvm-svn: 307598
This was originally reverted because of two issues.
1) Printing ANSI color escape codes even when outputting to
a file
2) Module name comparisons were failing when comparing a PDB
generated on one machine to a PDB generated on another
machine.
I attempted to fix#2 by adding command line options which let
you specify prefixes to strip from the beginning of embedded
paths, which effectively lets us specify a path to "base" each
PDB from and only compare the parts under the base. But this is
tricky because PDB paths always use Windows path syntax, even
when they are created on non-Windows hosts. A problem still
existed when constructing the prefix to strip, where we were
accidentally using a host-specific path separator instead of
a Windows path separator.
This resubmission fixes the issue on Linux (and I have verified
that the test now passes on Linux).
llvm-svn: 307571
A test was checked in on Friday that worked by checking in an
object file and PDB generated locally by MSVC, and then having
the test run lld-link on the object file and diffing LLD's PDB
against the checked in PDB.
This failed because part of the diffing algorithm involves
determining if two modules are the same, and if so drilling into
the module and diffing individual fields of the module. The
only thing we can use to make this determination though is the
"name" of the module, which is a path to where the module (obj
file) was read from on the machine where it was linked. This
fails for obvious reasons when comparing a PDB generated on one
machine to a PDB on another machine.
The fix employed here is to add two command line options to the
diff subcommand, which allow the user to specify a "binary root
path". The bin root path, if specified, is stripped from the
beginning of any embedded PDB paths. The test is updated to
specify the user's local test output directory for the left
PDB, and is hardcoded to the location where the original PDB
was created for the right PDB. This way all the equivalence
comparisons should succeed.
llvm-svn: 307555
This reverts commit 147f45ff24456aea59575fa4ac16c8fa554df46a.
Revert "Revert "Revert "Revert "Replace trivial use of external rc.exe by writing our own .res file.""""
This reverts commit 61a90a67ed54a1f0dfeab457b65abffa129569e4.
The patches were intially reverted because they were causing a failure
on CrWinClangLLD. Unfortunately, this was done haphazardly and didn't
compile, so the revert was reverted again quickly to fix this. One that
was done, the revert of the revert was itself reverted. This allowed me
to finally fix the actual bug in r307452. This patch re-enables the
code path that had originally been causing the bug, now that it (should)
be fixed.
llvm-svn: 307460
Summary:
The original cvtres.exe sets the high bit when an identifier offset
points to a string. Even though this is not mentioned in the spec, and
in fact does not seem to cause errors with most cases, for some reason
this causes a failure in Chromium where the new resource file is not
verified as a new version. This patch sets this high bit flag, and also
adds a test case to check that the output of our library is always
identical to original cvtres.
Reviewers: zturner, ruiu
Subscribers: llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D35099
llvm-svn: 307452
1) Don't write a /src/headerblock stream. This appears to be
written conditionally by MSVC, but it's not clear what the
condition is. For now, just remove it since we dont' know
what it is anyway and the particular pdb we've checked in
for the test doesn't have one.
2) Write a valid timestamp for the PDB file signature. This
leads to non-reproducible builds, but it matches the default
behavior of link, so it should be out default as well. If
we need reproducibility, we should add a separate command
line option for it that is off by default.
3) Write an empty FPO stream. MSVC seems to always write an
FPO stream. This change makes the stream directory match
up, although we still need to make the contents of the FPO
stream match.
llvm-svn: 307436
Some platforms require an explicit specialization of std::hash
for PdbRaw_FeaturesSig. Also a test involving case sensitivity
needed to be fixed. For now that particular check just accepts
any path even if they're completely different. Long term we
should output paths in the correct case to match MSVC.
llvm-svn: 307426
Without this we would just append whatever the user
wrote on the command line, so if we're in C:\foo
and we run lld-link bar/baz.obj, we would write
C:\foo\bar/baz.obj in various places in the PDB.
MSVC linker does not do this, so we shouldn't either.
This fixes some differences in the diff test, so we
update the test as well.
Differential Revision: https://reviews.llvm.org/D35092
llvm-svn: 307423
A couple of things were different about our generated PDBs.
1) We were outputting the wrong Version on the PDB Stream.
The version we were setting was newer than what MSVC is setting.
It's not clear what the implications are, but we change LLD
to use PdbImplVC70, as MSVC does.
2) For the optional debug stream indices in the DBI Stream, we
were outputting 0 to mean "the stream is not present". MSVC
outputs uint16_t(-1), which is the "correct" way to specify
that a stream is not present. So we fix that as well.
3) We were setting the PDB Stream signature to 0. This is supposed
to be the result of calling time(nullptr). Although this leads
to non-deterministic builds, a better way to solve that is by
having a command line option explicitly for generating a
reproducible build, and have the default behavior of lld-link
match the default behavior of link.
To test this, I'm making use of the new and improved `pdb diff`
sub command. To make it suitable for writing tests against, I had
to modify the diff subcommand slightly to print less verbose output.
Previously it would always print | <column> | <value1> | <value2> |
which is quite verbose, and the values are fragile. All we really
want to know is "did we produce the same value as link?" So I added
command line options to print a single character representing the
result status (different, identical, equivalent), and another to
hide the value display. Note that just inspecting the diff output
used to write the test, you can see some things that are obviously
wrong. That is just reflective of the fact that this is the state
of affairs today, not that we're asserting that this is "correct".
We can use this as a starting point to discover differences, fix
them, and update the test.
Differential Revision: https://reviews.llvm.org/D35086
llvm-svn: 307422
This is relative to PR33173,
Previously if something wrong happened on DWARF parsers side during parsing
object for building gdb index (like was in PR: unsupported relocation)
then LLD continued and finished the link. DWARF parsers sure showed error
message on their side, but that is all.
Patch changes behavior to fail the link in this case and show more
detailed message.
Differential revision: https://reviews.llvm.org/D34814
llvm-svn: 307370
This fixes last testcase provided in PR28414.
In short issue is next: when we had X@@Version symbol in object A,
we did not resolve it to X early. Then when in another object B
we had reference to undefined X, symbol X from archive was fetched.
Since both archive and object A contains another symbol Z, duplicate
symbol definition was triggered as a result.
Correct behavior is to use X@@Version from object A instead and do not fetch
any symbols from archive.
Differential revision: https://reviews.llvm.org/D35059
llvm-svn: 307364
Summary:
The capture() function was removed in r306625. This should fix PGO breakages
reported by Michael Zolotukhin.
Reviewers: mzolotukhin
Subscribers: sanjoy, llvm-commits
Differential Revision: https://reviews.llvm.org/D35088
llvm-svn: 307320
Summary:
There are a variety of records that open scopes: function scopes, block
scopes, and inlined call site scopes. These symbol records contain
Parent and End fields with the offsets of other symbol records. The End
field contains the offset of the matching S_END or S_INLINESITE_END
record. The Parent field contains the offset of the parent record, or 0
if this is a top-level scope (i.e. a function).
With this change, `llvm-pdbutil pretty -all` no longer crashes on PDBs
produced by LLD. I haven't tried a real debugger yet.
Reviewers: zturner, ruiu
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34898
llvm-svn: 307278
This reverts commit ae21ee0b6cacbc1efaf4d42502e71da2f0eb45c3.
The initial revert was done in order to prevent ongoing errors on
chromium bots such as CrWinClangLLD. However, this was done haphazardly
and I didn't realize there were test and compilation failures, so this
revert was reverted. Now that those have been fixed, we can revert the
revert of the revert.
llvm-svn: 307227
This reverts commit 5fecbbbe5049665d86834cf69d8f75db4f392308.
The initial revert was done in order to prevent ongoing errors on
chromium bots such as CrWinClangLLD. However, this was done haphazardly
and I didn't realize there were test and compilation failures, so this
revert was reverted. Now that those have been fixed, we can revert the
revert of the revert.
llvm-svn: 307226
This reverts commit 600d52c278e123dd08bee24c1f00932b55add8de.
This patch still seems to break CrWinClangLLD, reverting until I can
find root problem.
llvm-svn: 307189
This patch still seems to break CrWinClangLLD, reverting this once more
until I can discover root problem.
This reverts commit 3dbbc8ce43be50ffde2b1c655c6d3a25796fe78b.
llvm-svn: 307188
This is PR28414.
Previously LLD was unable to link following:
(failed with undefined symbol bar)
Version script:
SOME_VERSION { global: *; };
.global _start
.global bar
.symver _start, bar@@SOME_VERSION
_start:
jmp bar
Manual has next description:
.symver name, name2@@nodename
In this case, the symbol name must exist and be defined within the file being assembled. It is similar to name2@nodename.
The difference is name2@@nodename will also be used to resolve references to name2 by the linker
https://sourceware.org/binutils/docs/as/Symver.html
Patch implements that. If we have name@@ver symbol and name is undefined, name@@ver is used to resolve references to name.
If name is defined then multiple definition error is emited, that is consistent with what bfd do.
Differential revision: https://reviews.llvm.org/D33680
llvm-svn: 307077
Script commands are processed before unused synthetic sections are
removed. Therefore, if a linker script matches one of these sections
it'll get emitted as an empty output section because the logic for
removing unused synthetic sections ignores script commands which
could have already matched and captured one of these sections. This
patch fixes that by also removing the unused synthetic sections from
the script commands.
Differential Revision: https://reviews.llvm.org/D34800
llvm-svn: 307037
Since yaml2obj is now able to parse integer values as relocation types,
there is no need to keep hex edited elf object for this test,
we can produce it on fly, just like this patch do.
Differential revision: https://reviews.llvm.org/D34893
llvm-svn: 307032
This patch makes changes to allow sections without the SHF_ALLOC bit to be
assigned to segments in a linker script.
The assignment of output sections to segments is performed in
LinkerScript::createPhdrs. Previously, this function would bail as soon as it
encountered an output section which did not have the SHF_ALLOC bit set, thus
preventing any output section without SHF_ALLOC from being assigned to a
segment.
This restriction has now been removed from LinkerScript::createPhdrs and instead
a check for SHF_ALLOC has been added to LinkerScript::adjustSectionsAfterSorting
to not propagate program headers to sections without SHF_ALLOC which matches the
behaviour of bfd linker scripts.
Differential Revision: https://reviews.llvm.org/D34204
llvm-svn: 307013
A plain empty entry point function that returns 0 seems to produce
a binary that loads and runs fine in wine.
Differential Revision: https://reviews.llvm.org/D34833
llvm-svn: 306963
Summary:
This reverts commit 51931072a7c9a52540baf76fc30ef391d2529a2f.
This revert was originally done because the integrations of the new
WindowsResource library into LLD was causing error in chromium, due to
bugs in how resource sections were handled. These bugs were fixed,
meaning that the features may be reintegrated.
Subscribers: hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D34922
llvm-svn: 306941
Type records have a unique type index, but symbol records do
not. Instead, symbol records refer to other symbol records
by referencing their offset in the symbol stream. In a sense
this is the analogue of the TypeIndex, but we are not printing
it in the dumper. Printing it not only gives us more useful
information when manually investigating the contents of a PDB,
but also allows us to write better tests by enabling us to
verify that fields that reference other symbol records do
so correctly.
Differential Revision: https://reviews.llvm.org/D34906
llvm-svn: 306890
Summary:
There have been bugs with the WindowsResource library, such as incorrect
symbols for addresses. Directly checking the .rsrc in the final PE will
help ensure this doesn't happen again.
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34900
llvm-svn: 306854
This is PR28414.
Previously LLD was unable to link following:
(failed with undefined symbol bar)
```
Version script:
SOME_VERSION { global: *; };
.global _start
.global bar
.symver _start, bar@@SOME_VERSION
_start:
jmp bar
```
Manual has next description:
//
.symver name, name2@@nodename
In this case, the symbol name must exist and be defined within the file being assembled. It is similar to name2@nodename.
**The difference is name2@@nodename will also be used to resolve references to name2 by the linker**
https://sourceware.org/binutils/docs/as/Symver.html
//
Patch implements that. If we have name@@ver symbol and name is undefined,
name@@ver is used to resolve references to name.
Differential revision: https://reviews.llvm.org/D33680
llvm-svn: 306813
This reverts commit d4c7e9fc63c10dbab0c30186ef8575474a704496.
This is done in order to address the failure of CrWinClangLLD etc. bots.
These throw an error of "side-by-side configuration is incorrect" during
compilation, which sounds suspiciously related to these manifest
changes.
Revert "Switch external cvtres.exe for llvm's own resource library."
This reverts commit 71fe8ef283a9dab9a3f21432c98466cbc23990d1.
llvm-svn: 306618
Summary:
In order to do this without switching on the symbol kind multiple times,
I created Defined::getChunkAndOffset and use that instead of
SymbolBody::getRVA in the inner relocation loop.
Now we get the symbol's chunk before switching over relocation types, so
we can test if it has been discarded outside the inner relocation type
switch. This also simplifies application of section relative
relocations. Previously we would switch on symbol kind to compute the
RVA, then the relocation type, and then the symbol kind again to get the
output section so we could subtract that from the symbol RVA. Now we
*always* have an OutputSection, so applying SECREL and SECTION
relocations isn't as much of a special case.
I'm still not quite happy with the cleanliness of this code. I'm not
sure what offsets and bases we should be using during the relocation
processing loop: VA, RVA, or OutputSectionOffset.
Reviewers: ruiu, pcc
Reviewed By: ruiu
Subscribers: majnemer, inglorion, llvm-commits, aprantl
Differential Revision: https://reviews.llvm.org/D34650
llvm-svn: 306566
Add support for the most common SPARC relocations.
Make DT_PLTGOT point to the PLT on SPARC.
Mark the PLT as executable on SPARC.
This adds a basic test that creates a SPARV9 executable
that invokes the exit system call on OpenBSD.
Patch by Mark Kettenis.
Differential Revision: https://reviews.llvm.org/D34618
llvm-svn: 306565
This is PR33596. Previously LLD would crash
because BYTE command synthesized output section,
but it was not assigned to Sec member of OutputSectionCommand.
Behaviour of -script and -r combination is not well defined,
but it seems after this change LLD naturally inherits behavior of
GNU linkers - creates output section requested in script and does not
crash anymore.
Differential revision: https://reviews.llvm.org/D34676
llvm-svn: 306527
This fixes PR33598.
Size field for undefined symbols is not significant.
Setting it to fixed value, like zero, may be useful though.
For example when we have 2 DSO's, like in this PR, if lower level DSO may
change slightly (in part of some symbol's st_size) and higher-level DSO is
rebuilt, then tools that monitoring checksum of high level DSO file can notice
it and trigger cascade of some other unnecessary actions.
If we set st_size to zero, that can be avoided.
Differential revision: https://reviews.llvm.org/D34673
llvm-svn: 306526
When -ffunction-sections and ARM C++ exceptions are used each .text.suffix
section will have at least one .ARM.exidx.suffix section and may have an
additional .ARM.extab.suffix section if the unwinding instructions are too
large to inline into the .ARM.exidx table entry. For a large program without
a linker script this can lead to a large number of section header table
entries that can increase the size of the ELF file.
This change introduces a default rule for .ARM.extab.* to be placed in
a single output section called .ARM.extab . This follows the behavior of
ld.gold and ld.bfd.
fixes pr33407
Differential Revision: https://reviews.llvm.org/D34678
llvm-svn: 306522
It is somewhat pointless to check that a specific error is not
produced. That is already checked by the ld.lld exit value.
Instead make the test a bit stronger by checking that the output file
has the expected symbol and section.
llvm-svn: 306496
Summary: The testing on the resource section of executables produced by lld has been very lax, and allowed a major bug to go unnoticed when we switched from shelling out to cvtres.exe to using llvm's own library. These additional tests should cover all the major failure points.
Reviewers: zturner, ruiu
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34664
llvm-svn: 306465
This patch fills holes in executable sections with 0xd4 (ARM) or
0xef (MIPS). These trap instructions were suggested by Theo de Raadt.
llvm-svn: 306322
This patch removes the dependency on the external rc.exe tool by writing
a simple .res file using our own library. In this patch I also added an
explicit definition for the .res file magic. Furthermore, I added a
unittest for embeded manifests and fixed a bug exposed by the test.
llvm-svn: 306311
Summary:
They do the obvious thing: provide the section index of .bss and the
offset of the symbol in .bss.
Reviewers: ruiu
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34628
llvm-svn: 306304
Over time we've started to add inputs and test cases using the .yaml
extension, which seems to be preferred over the .objtxt extension that
we were using initially. One nice thing about using .yaml is that it
triggers existing editor highlighting and formatting support.
Fix two pdb*.yaml test cases that I added that weren't being run as part
of check-lld.
llvm-svn: 306303
Summary:
The main change is that we can have SECREL and SECTION relocations
against ___safe_se_handler_table, which is important for handling the
debug info in the MSVCRT.
Previously we were using DefinedRelative for __safe_se_handler_table and
__ImageBase, and after we implement CFGuard, we plan to extend it to
handle __guard_fids_table, __guard_longjmp_table, and more. However,
DefinedRelative is really only suitable for implementing __ImageBase,
because it lacks a Chunk, which you need in order to figure out the
output section index and output section offset when resolving SECREl and
SECTION relocations.
This change renames DefinedRelative to DefinedSynthetic and gives it a
Chunk. One wart is that __ImageBase doesn't have a chunk. It points to
the PE header, effectively. We could split DefinedRelative and
DefinedSynthetic if we think that's cleaner and creates fewer special
cases.
I also added safeseh.s, which checks that we don't emit a safe seh table
entries pointing to garbage collected handlers and that we don't emit a
table at all when there are no handlers.
Reviewers: ruiu
Reviewed By: ruiu
Subscribers: inglorion, pcc, llvm-commits, aprantl
Differential Revision: https://reviews.llvm.org/D34577
llvm-svn: 306293
On many architectures gcc and clang will recognize _GLOBAL_OFFSET_TABLE_ - .
and produce a relocation that can be processed without needing to know the
value of _GLOBAL_OFFSET_TABLE_. This is not always the case; for example ARM
gcc produces R_ARM_BASE_PREL but clang produces the more general
R_ARM_REL32 to _GLOBAL_OFFSET_TABLE_. To evaluate this relocation
correctly _GLOBAL_OFFSET_TABLE_ must be defined to be the either the base of
the GOT or end of the GOT dependent on architecture..
If/when llvm-mc is changed to recognize _GLOBAL_OFFSET_TABLE_ - . this
change will not be necessary for new objects. However there may still be
old objects and versions of clang.
Differential Revision: https://reviews.llvm.org/D34355
llvm-svn: 306282
This is useful when an upper limit on the cache size needs to be
controlled independently of the amount of the amount of free space.
One use case is a machine with a large number of cache directories
(e.g. a buildbot slave hosting a large number of independent build
jobs). By imposing an upper size limit on each cache directory,
users can more easily estimate the server's capacity.
Differential Revision: https://reviews.llvm.org/D34547
llvm-svn: 306126
Summary:
For SECTION relocations against absolute symbols, MSVC emits the largest
output section index plus one. I've implemented that by threading a
global variable through DefinedAbsolute that is filled in by the Writer.
A more library-oriented approach would be to thread the Writer through
Chunk::writeTo and SectionChunk::applyRel*, but Rui seems to prefer
doing it this way.
MSVC rejects SECREL relocations against absolute symbols, but only when
the relocation is in a real output section. When the relocation is in a
CodeView debug info section destined for the PDB, it seems that this
relocation error is suppressed, and absolute symbols become zeros in the
object file. This is easily implemented by checking the input section
from which we're applying relocations.
This should fix errors about __safe_se_handler_table and
__guard_fids_table when linking the CRT and generating a PDB.
Reviewers: ruiu
Subscribers: aprantl, llvm-commits
Differential Revision: https://reviews.llvm.org/D34541
llvm-svn: 306071
Now you run llvm-pdbutil dump <options>. This is a followup
after having renamed the tool, whereas before raw was obviously
just the style of dumping, whereas now "dump" is the action to
perform with the "util".
llvm-svn: 306055
Previously, when symbol A is renamed B, both A and B end up having
the same name. This is because name is a symbol's attribute, and
we memcpy symbols for symbol renaming.
This pathc saves the original symbol name and restore it after memcpy
to keep the original name.
This patch shouldn't change program's meaning, but names in symbol
tables make more sense than before.
llvm-svn: 306036
Summary:
The main complexity in adding symbol records is that we need to
"relocate" all the type indices. Type indices do not have anything like
relocations, an opaque data structure describing where to find existing
type indices for fixups. The linker just has to "know" where the type
references are in the symbol records. I added an overload of
`discoverTypeIndices` that works on symbol records, and it seems to be
able to link the standard library.
Reviewers: zturner, ruiu
Subscribers: llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D34432
llvm-svn: 305933
This works around a strange interaction with Authenticode signatures,
in which a signed PE executable with {Major,Minor}LinkerVersion = 0.0
fails to validate on Windows 7 (but is OK on Windows 10). Setting the
linker version to 14.0 (which is what VS2015 outputs) makes it work
again.
Patch by Simon Tatham <simon.tatham@arm.com>.
llvm-svn: 305929
The --exclude-libs option is not a popular option, but at least some
programs in Android depend on it, so it's worth to support it.
Differential Revision: https://reviews.llvm.org/D34422
llvm-svn: 305920
VC2017 contains these new symbols as undefined symobls. They are used
for /guard:cf. Since we do not support the control flow guard, but we
want to at least ignore these symbols so that we can link against VS2017
libraries.
Fixes https://bugs.chromium.org/p/chromium/issues/detail?id=727193.
llvm-svn: 305876
We forgot to serialize these because llvm-readobj didn't dump them. They
are typically all zeros in an object file. The linker fills them in with
relocations before adding them to the PDB. Now we can properly round
trip these symbols through pdb2yaml -> yaml2pdb.
I made these fields optional with a zero default so that we can elide
them from our test cases.
llvm-svn: 305857
Summary:
Previously we didn't add debug info chunks to the SparseChunks array, so
they didn't participate in section GC. Now we do.
Reviewers: ruiu
Subscribers: aprantl, llvm-commits
Differential Revision: https://reviews.llvm.org/D34356
llvm-svn: 305811
I found this while trying to build u-boot. It uses -Ttext in
combination with linker scripts.
My first reaction was to change the linker scripts to have the correct
value, but I found that it is actually quite convenient to have -Ttext
take precedence.
By having just
.text : { *(.text) }
In the script, they can define the text address in a single Makefile
and pass it to ld with -Ttext and for the C code with
-DFoo=value. Doing the same with linker scripts would require them to
be generated during the build.
llvm-svn: 305766
Summary:
This is a first step towards getting line info to show up in VS and
windbg. So far, only llvm-pdbutil can parse the PDBs that we produce.
cvdump doesn't like something about our file checksum tables. I'll have
to dig into that next.
This patch adds a new DebugSubsectionRecordBuilder which takes bytes
directly from some other producer, such as a linker, and sticks it into
the PDB. Line tables only need to be relocated. No data needs to be
rewritten.
File checksums and string tables, on the other hand, need to be re-done.
Reviewers: zturner, ruiu
Subscribers: llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D34257
llvm-svn: 305713
This patch adds support for segment NONE in linker scripts which enables the
specification that a section should not be assigned to any segment.
Note that GNU ld does not disallow the definition of a segment named NONE, which
if defined, effectively overrides the behaviour described above. This feature
has been copied.
Differential Revision: https://reviews.llvm.org/D34203
llvm-svn: 305700
In r305364, Rui changed the mechanism that parses -z option values slightly.
This caused a bug, as demonstrated by this test, which now fails:
---
# REQUIRES: x86
# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
# RUN: ld.lld %t.o -o %t -z max-page-size
.global _start
_start:
nop
---
Before, the link succeeded and set the max-page-size to the target default.
After we get the following two error messages:
"invalid max-page-size: "
"max-page-size: value isn't a power of 2"
The latter error is because an uninitialised variable ends up being passed back
to getMaxPageSize).
This change ensures we only get the first error.
Reviewers: ruiu
Differential Revision: https://reviews.llvm.org/D34234
llvm-svn: 305679
In this patch, I flip the switch in DriverUtils from using the external
cvtres.exe tool to using the Windows Resource library in llvm.
I also fixed a bug where .rsrc sections were marked as discardable
memory and therefore were placed in the wrong order in the final PE.
Furthermore, I modified WindowsResource to write the coff directly to a
memory buffer instead of to file, also had it use the machine types
already declared in COFF.h instead creating my own enum.
Finally, I flipped the switch to allow all unit tests that had
previously run only on windows due to a winres dependency to run
cross-platform.
Reviewers: zturner, ruiu
Subscribers: llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D34265
llvm-svn: 305592
Summary:
Adds a "Discarded" bool to SectionChunk to indicate if the section was
discarded by COMDAT deduplication. The Writer still just checks
`isLive()`.
Fixes PR33446
Reviewers: ruiu
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34288
llvm-svn: 305582
This resubmits commit c0c249e9f2ef83e1d1e5f166b50673d92f3579d7.
It was broken due to some weird template issues, which have
since been fixed.
llvm-svn: 305517
This reverts commit 83ea17ebf2106859a51fbc2a86031b44d33696ad.
This is failing due to some strange template problems, so reverting
until it can be straightened out.
llvm-svn: 305505
When link is invoked with `/def:` and no input files, it behaves as if
`lib.exe` was invoked. Emulate this behaviour, generating the import
library from the def file that was passed. Because there is no input to
actually generate the dll, we simply process the def file early and exit
once we have created the import library.
llvm-svn: 305502
After some internal discussions, we agreed that the raw output style had
outlived its usefulness. It was originally created before we had even
thought of dumping to YAML, and it was intended to give us some insight
into the internals of a PDB file. Now we have YAML mode which does
almost exactly this but is more powerful in that it can round-trip back
to a PDB, which the raw mode could not do. So the raw mode had become
purely a maintenance burden.
One option was to just delete it. However, its original goal was to be
as readable as possible while staying close to the "metal" - i.e.
presenting the output in a way that maps directly to the underlying file
format. We don't actually need that last requirement anymore since it's
covered by the yaml mode, so we could repurpose "raw" mode to actually
just be as readable as possible.
This patch implements about 80% of the functionality previously in raw
mode, but in a completely different style that is more akin to what
cvdump outputs. Records are very compressed, often times appearing on
just one line. One nice thing about this is that it makes full record
matching easier, because you can grep for indices, names, and leaf types
on a single line often.
See the tests for some examples of what the new output looks like.
Note that this patch actually regresses the functionality of raw mode in
a few areas, but only because the patch was already unreasonably large
and going 100% would have been even worse. Specifically, this patch is
missing:
The ability to dump module debug subsections (checksums, lines, etc)
The ability to dump section headers
Aside from that everything is here. While goign through the tests fixing
them all up, I found many duplicate tests. They've been deleted. In
subsequent patches I will go through and re-add the missing
functionality.
Differential Revision: https://reviews.llvm.org/D34191
llvm-svn: 305495
This is necessary to ensure that sections containing symbols referenced
from linker scripts (e.g. in data commands) don't get GC'd.
Differential Revision: https://reviews.llvm.org/D34195
llvm-svn: 305452
This was originally reverted because of some non-deterministic
failures on certain buildbots. Luckily ASAN eventually caught
this as a stack-use-after-scope, so the fix is included in
this patch.
llvm-svn: 305393
This is causing failures on linux bots with an invalid stream
read. It doesn't repro in any configuration on Windows, so
reverting until I have a chance to investigate on Linux.
llvm-svn: 305371
This allows us to use yaml2obj and obj2yaml to round-trip CodeView
symbol and type information without having to manually specify the bytes
of the section. This makes for much easier to maintain tests. See the
tests under lld/COFF in this patch for example. Before they just said
SectionData: <blob> whereas now we can use meaningful record
descriptions. Note that it still supports the SectionData yaml field,
which could be useful for initializing a section to invalid bytes for
testing, for example.
Differential Revision: https://reviews.llvm.org/D34127
llvm-svn: 305366
Currently we do layout as if non alloc sections had an actual address
and then set it to zero. This produces a few odd results where a
symbol has an address that is inconsistent with the section address.
The simplest way to fix it is probably to just set the address earlier.
The behavior of bfd seems to be similar, but it only sets the non
alloc section address is missing from the linker script or if the
script has an explicit " : 0" setting the address of the output
section (which the default script does).
llvm-svn: 305323
This means that 'llvm-pdbutil' in test commands will resolve
to the absolute path to the tool, in line with what happens
already for other tools.
This works either way because the bin directory is also
prepended to the PATH. I'm not sure why both methods are
used.
Differential Revision: https://reviews.llvm.org/D34128
llvm-svn: 305297
Summary:
Expose the module descriptor index and fill it in for section
contributions.
Reviewers: zturner
Subscribers: llvm-commits, ruiu, hiraditya
Differential Revision: https://reviews.llvm.org/D34126
llvm-svn: 305296
This shows an oddity of this output. While the section address is 0,
the the symbol address is computed as if the section was allocatable.
llvm-svn: 305250
The last fix required the user to manually add the required
feature. This caused an LLD test to fail because I failed to
update LLD. In practice we can hide this logic so it can just
be transparently added when we write the PDB.
llvm-svn: 305236
The ELF standard defines that the SHT_GROUP section as follows:
- its sh_link has the symbol index, and
- the symbol name is used to uniquify section groups.
Object files created by GNU gold does not seem to comply with the
standard. They have this additional rule:
- if the symbol has no name and a STT_SECTION symbol, a section
name is used instead of a symbol name.
If we don't do anything for this, the linker fails with a mysterious
error message if input files are generated by gas. It is unfortunate
but I think we need to support it.
Differential Revision: https://reviews.llvm.org/D34064
llvm-svn: 305218
Given
.weak target
.global _start
_start:
b target
The intention is that the branch goes to the instruction after the
branch, effectively turning it on a nop. The branch adds the runtime
PC, but we were adding it statically too.
I noticed the oddity by inspection, but llvm-objdump seems to agree,
since it now prints things like:
b #-4 <_start+0x4>
llvm-svn: 305212
Relocations referring to merge sections are considered equal if they
resolve to the same offset in the same output section.
Differential Revision: https://reviews.llvm.org/D34094
llvm-svn: 305177
Currently the freebsd early boot code fails to link. The issue reduces
to 16 bit code at position 0x7000 wanting to jump to position
0x9000. That is represented in the .o file as a relocation with no
symbol and an addend of 0x9000 - 2 (The -2 is because i386 uses the ip
after the current instruction for jumps).
If the addend is interpreted as signed (it should), it is -28674. In a
32 bit architecture, that is the address 0xffff8ffe. To get there from
0x7000 we have to add 4294909950 (too big) or subtract 57346 (too
small). We then produce an error.
What lld is missing is the fact that at runtime this will actually be
a 16 bit architecture and adding 0x1ffe produces 0x8ffe which is the
correct result in 16 bits (-28674).
Since we have a 16 bit addend and a 16 bit PC, the relocation can move
the PC to any 16 bit address and that is the only thing we really need
to check: if the address we are pointing to fits in 16 bits. This is
unfortunately hard to do since we have to delay subtracting the PC and
if we want to do that outside of Target.cpp, we have to move the
overflow check out too. An incomplete patch that tries to do that is
at https://reviews.llvm.org/D34070
This patch instead just relaxes the check. Since the value we have is
the destination minus the PC and the PC is 16 bits, it should fit in
17 bits if the destination fits in 16 too.
bfd had a similar issue for some time and got a similar fix:
https://sourceware.org/ml/binutils/2005-08/msg00001.html
llvm-svn: 305135
SHF_GROUP bit doesn't make sense in executables or DSOs, so linkers are
expected to remove that bit from section flags. We did that when we create
output sections.
This patch is to do that earlier than before. Now the flag is dropped when
we instantiate input section objects.
This change improves ICF. Previously, two sections that differ only in
SHF_GROUP flag were not merged, because when the control reached ICF,
the flag was still there. Now the flag is dropped before reaching to ICF,
so the difference is ignored naturally.
This issue was found by pcc.
Differential Revision: https://reviews.llvm.org/D34074
llvm-svn: 305134
This is to reflect the evolving nature of the tool as being
useful for more than just dumping PDBs, as it can do many other
things.
Differential Revision: https://reviews.llvm.org/D34062
llvm-svn: 305106
This is used by linux kernel build system.
(https://www.kernel.org/doc/Documentation/kbuild/makefiles.txt "3.2 Built-in object goals")
It has for example next configuration for linking built-in.o files:
drivers-y := $(patsubst %/, %/built-in.o, $(drivers-y))
drivers-$(CONFIG_PCI) += arch/ia64/pci/
...
drivers-$(CONFIG_OPROFILE) += arch/ia64/oprofile/
Im most simple case all CONFIG_* options are off. That means linker is called with empty input archive,
emulation option and no inputs and expected to generate some relocatable output.
ld.bfd is able to do that, we dont.
Patch allows to support this case.
Differential revision: https://reviews.llvm.org/D33937
llvm-svn: 305069
The symbols generated for Thunks have type STT_FUNC, to permit a thunk to
be reused via a blx instruction the Thumb bit (0) needs to be set properly.
Differential Revision: https://reviews.llvm.org/D34036
llvm-svn: 305065
Previously, it couldn't parse
SECTIONS .text (0x1000) : { *(.text) }
because "(" was interpreted as the begining of the "(NOLOAD)" directive.
llvm-svn: 305006
Thunks are now generated per InputSectionDescription instead of per
OutputSection. This allows created ThunkSections to be inserted directly
into InputSectionDescription.
Changes in this patch:
- Loop over InputSectionDescriptions to find relocations to Thunks
- Generate a ThunkSection per InputSectionDescription
- Remove synchronize() as we no longer need it
- Move fabricateDefaultCommands() before createThunks
Differential Revision: https://reviews.llvm.org/D33835
llvm-svn: 304887
Reid Kleckner