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:
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
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
Summary:
Currently we are pointing all debug information that refer removed function code
to the beginning of the code section (offset = 0). A debugger may want to
resolve code offset to the debug information, which will collide with offsets
of the live functions.
Moving offsets of dead functions outside code section range.
Reviewers: sbc100
Reviewed By: sbc100
Subscribers: dblaikie, ruiu, alexcrichton, dschuff, aprantl, jgravelle-google, aheejin, sunfish, JDevlieghere, llvm-commits
Differential Revision: https://reviews.llvm.org/D49446
llvm-svn: 342930
Implement final argument precedence if multiple /debug arguments are passed on the command-line to match expected link.exe behavior.
Support /debug:none and emit warning for /debug:fastlink with automatic fallback to /debug:full.
Emit error if last /debug:option is unknown.
Emit warning if last /debugtype:option is unknown.
https://reviews.llvm.org/D50404
llvm-svn: 342894
GNU binutils import libraries aren't the same kind of short import
libraries as link.exe and LLD produce, but are a plain static library
containing .idata section chunks. MSVC link.exe can successfully link
to them.
In order for imports from GNU import libraries to mix properly with the
normal import chunks, the chunks from the existing mechanism needs to
be added into named sections like .idata$2.
These GNU import libraries consist of one header object, a number of
object files, one for each imported function/variable, and one trailer.
Within the import libraries, the object files are ordered alphabetically
in this order. The chunks stemming from these libraries have to be
grouped by what library they originate from and sorted, to make sure
the section chunks for headers and trailers for the lists are ordered
as intended. This is done on all sections named .idata$*, before adding
the synthesized chunks to them.
Differential Revision: https://reviews.llvm.org/D38513
llvm-svn: 342777
Summary:
As for x86_64, the default image base for AArch64 and i386 should be
aligned to a superpage appropriate for the architecture.
On AArch64, this is 2 MiB, on i386 it is 4 MiB.
Reviewers: emaste, grimar, javed.absar, espindola, ruiu, peter.smith, srhines, rprichard
Reviewed By: ruiu, peter.smith
Subscribers: jfb, markj, arichardson, krytarowski, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D50297
llvm-svn: 342746
The access sequence for global variables in the medium and large code models use
2 instructions to add an offset to the toc-pointer. If the offset fits whithin
16-bits then the instruction that sets the high 16 bits is redundant.
This patch adds the --toc-optimize option, (on by default) and enables rewriting
of 2 instruction global variable accesses into 1 when the offset from the
TOC-pointer to the variable (or .got entry) fits in 16 signed bits. eg
addis %r3, %r2, 0 --> nop
addi %r3, %r3, -0x8000 --> addi %r3, %r2, -0x8000
This rewriting can be disabled with the --no-toc-optimize flag
Differential Revision: https://reviews.llvm.org/D49237
llvm-svn: 342602
Summary:
For --pack-dyn-relocs=android, finalizeSections calls
LinkerScript::assignAddresses and
AndroidPackedRelocationSection::updateAllocSize in a loop,
where assignAddresses lays out the ELF image, then updateAllocSize
determines the size of the Android packed relocation table by encoding it.
Encoding the table requires knowing the values of relocation addends.
To get the addend of a TLS relocation, updateAllocSize can call getSymVA
on a TLS symbol before setPhdrs has initialized Out::TlsPhdr, producing an
error:
<file> has an STT_TLS symbol but doesn't have an SHF_TLS section
Fix the problem by initializing Out::TlsPhdr immediately after the program
headers are created. The segment's p_vaddr field isn't initialized until
setPhdrs, so use FirstSec->Addr, which is what setPhdrs would use.
FirstSec will typically refer to the .tdata or .tbss output section, whose
(tentative) address was computed by assignAddresses.
Android currently avoids this problem because it uses emutls and doesn't
support ELF TLS. This problem doesn't apply to --pack-dyn-relocs=relr
because SHR_RELR only handles relative relocations without explicit addends
or info.
Fixes https://bugs.llvm.org/show_bug.cgi?id=37841.
Reviewers: ruiu, pcc, chh, javed.absar, espindola
Subscribers: emaste, arichardson, llvm-commits, srhines
Differential Revision: https://reviews.llvm.org/D51671
llvm-svn: 342432
A General-dynamic tls access can be written using a R_PPC64_TLSGD16 relocation
if the target got entry is within 16 bits of the TOC-base. This patch adds
support for R_PPC64_TLSGD16 by relaxing it the same as a R_PPC64_GOT_TLSGD16_LO.
Differential Revision: https://reviews.llvm.org/D52055
llvm-svn: 342411
dllimported symbols go through an import stub that's called __imp_ followed by
the name the stub points to. Make that work.
Differential Revision: https://reviews.llvm.org/D52145
llvm-svn: 342401
Previously, lld-link would use a random byte sequence as the PDB GUID. Instead,
use a hash of the PDB file contents.
To not disturb llvm-pdbutil pdb2yaml, the hash generation is an opt-in feature
on InfoStreamBuilder and ldb/COFF/PDB.cpp always sets it.
Since writing the PDB computes this ID which also goes in the exe, the PDB
writing code now must be called before writeBuildId(). writeBuildId() for that
reason is no longer included in the "Code Layout" timer.
Since the PDB GUID is now a function of the PDB contents, the PDB Age is always
set to 1. There was a long comment above loadExistingBuildId (now gone) about
how not changing the GUID and only incrementing the age was important, but
according to the discussion in PR35914 that comment was incorrect.
Differential Revision: https://reviews.llvm.org/D51956
llvm-svn: 342334
For this, add a few toString() calls when printing the "undefined symbol"
diagnostics; toString() already does demangling on Windows hosts.
Also make lld::demangleMSVC() (called by toString(Symbol*)) call LLVM's
microsoftDemangle() instead of UnDecorateSymbolName() so that it works on
non-Windows hosts – this makes both updating tests easier and provides a better
user experience for people doing cross-links.
This doesn't yet do the right thing for symbols starting with __imp_, but that
can be improved in a follow-up.
Differential Revision: https://reviews.llvm.org/D52104
llvm-svn: 342332
MinGW uses these kind of list terminator symbols for traversing
the constructor/destructor lists. These list terminators are
actual pointers entries in the lists, with the values 0 and
(uintptr_t)-1 (instead of just symbols pointing to the start/end
of the list).
(This mechanism exists in both the mingw-w64 crt startup code and
in libgcc; normally the mingw-w64 one is used, but a DLL build of
libgcc uses the libgcc one. Therefore it's not trivial to change
the mechanism without lots of cross-project synchronization and
potentially invalidating some combinations of old/new versions
of them.)
When mingw-w64 has been used with lld so far, the CRT startup object
files have so far provided these symbols, ending up with different,
incompatible builds of the CRT startup object files depending on
whether binutils or lld are going to be used.
In order to avoid the need of different configuration of the CRT startup
object files depending on what linker to be used, provide these symbols
in lld instead. (Mingw-w64 checks at build time whether the linker
provides these symbols or not.) This unifies this particular detail
between the two linkers.
This does disallow the use of the very latest lld with older versions
of mingw-w64 (the configure check for the list was added recently;
earlier it simply checked whether the CRT was built with gcc or clang),
and requires rebuilding the mingw-w64 CRT. But the number of users of
lld+mingw still is low enough that such a change should be tolerable,
and unifies this aspect of the toolchains, easing interoperability
between the toolchains for the future.
The actual test for this feature is added in ctors_dtors_priority.s,
but a number of other tests that checked absolute output addresses
are updated.
Differential Revision: https://reviews.llvm.org/D52053
llvm-svn: 342294
-z interpose sets the DF_1_INTERPOSE flag, marking the object as an
interposer.
Via FreeBSD PR 230604, linking Valgrind with lld failed.
Differential Revision: https://reviews.llvm.org/D52094
llvm-svn: 342239
The PE spec says that they will be separated by spaces, but link.exe
handles it just fine if they are separated by null bytes as well.
This adds tests to the lld repo, with the actual functional change
in LLVM in SVN r342204.
Differential Revision: https://reviews.llvm.org/D52014
llvm-svn: 342206
Patch by Thomas Roughton.
This patch adds support for linking with multiple definitions to LLD's
COFF driver, in line with link.exe's /force:multiple option.
Differential Revision: https://reviews.llvm.org/D50598
llvm-svn: 342191
For lld-link missing.obj, lld-link currently prints:
lld-link: error: could not open foo.obj: No such file or directory
lld-link: warning: /machine is not specified. x64 is assumed
lld-link: error: subsystem must be defined
The 2nd and 3rd diagnostics are consequences of the input not existing and are
not interesting. If input files are missing, the best thing we can do is point
that out and then return.
Differential Revision: https://reviews.llvm.org/D51981
llvm-svn: 342158
If --just-syms is used the mapping symbols from the ELF file will be
absolute symbols with no section. The code to process mapping symbols in
--fix-cortex-a53-843419 assumes that these symbols have a defining section
so a crash will result when --just-syms is used. The simple fix is to not
process the symbol when it doesn't have a section.
Fixes PR37971
Differential Revision: https://reviews.llvm.org/D52038
llvm-svn: 342146
r342003 added support for emitting FPO data from the
DEBUG_S_FRAMEDATA subsection of the .debug$S section to the PDB
file. However, that is not the end of the story. FPO can end
up in two different destinations in a PDB, each corresponding to
a different FPO data source.
The case handled by r342003 involves copying data from the
DEBUG_S_FRAMEDATA subsection of the .debug$S section to the
"New FPO" stream in the PDB, which is then referred to by the
DBI stream. The case handled by this patch involves copying
records from the .debug$F section of an object file to the "FPO"
stream (or perhaps more aptly, the "Old FPO" stream) in the PDB
file, which is also referred to by the DBI stream.
The formats are largely similar, and the difference is mostly
only visible in masm generated object files, such as some of the
low-level CRT object files like memcpy. MASM doesn't appear to
support writing the DEBUG_S_FRAMEDATA subsection, and instead
just writes these records to the .debug$F section.
Although clang-cl does not emit a .debug$F section ever, lld still
needs to support it so we have good debugging for CRT functions.
Differential Revision: https://reviews.llvm.org/D51958
llvm-svn: 342080
Summary:
There are two registers encoded in the S_FRAMEPROC flags: one for locals
and one for parameters. The encoding is described by the
ExpandEncodedBasePointerReg function in cvinfo.h. Two bits are used to
indicate one of four possible values:
0: no register - Used when there are no variables.
1: SP / standard - Variables are stored relative to the standard SP
for the ISA.
2: FP - Variables are addressed relative to the ISA frame
pointer, i.e. EBP on x86. If realignment is required, parameters
use this. If a dynamic alloca is used, locals will be EBP relative.
3: Alternative - Variables are stored relative to some alternative
third callee-saved register. This is required to address highly
aligned locals when there are dynamic stack adjustments. In this
case, both the incoming SP saved in the standard FP and the current
SP are at some dynamic offset from the locals. LLVM uses ESI in
this case, MSVC uses EBX.
Most of the changes in this patch are to pass around the CPU so that we
can decode these into real, named architectural registers.
Subscribers: hiraditya
Differential Revision: https://reviews.llvm.org/D51894
llvm-svn: 341999
- Log the reason for a PDB or precompiled-OBJ load failure
- Properly handle out-of-date PDB or precompiled-OBJ signature by displaying a corresponding error
- Slightly change behavior on PDB failure: any subsequent load attempt from another OBJ would result in the same error message being logged
- Slightly change behavior on PDB failure: retry with filename only if previous error was ENOENT ("no such file or directory")
- Tests: a. for native PDB errors; b. cover all the cases above
Differential Revision: https://reviews.llvm.org/D51559
llvm-svn: 341825
Summary: This protects lld from a null pointer dereference when a faulty input file has such invalid sh_link fields.
Reviewers: ruiu, espindola
Reviewed By: ruiu
Subscribers: emaste, arichardson, llvm-commits
Differential Revision: https://reviews.llvm.org/D51743
llvm-svn: 341611
Summary:
r338767 updated the COFF and wasm linker SymbolTable code to be
strutured more like the ELF linker's. That inadvertedly changed the
behavior of the COFF linker so that lazy symbols would be marked as
used in regular objects. This change adds an overload of the insert()
function, similar to the ELF linker, which does not perform that
marking.
Reviewers: ruiu, rnk, hans
Subscribers: aheejin, sunfish, llvm-commits
Differential Revision: https://reviews.llvm.org/D51720
llvm-svn: 341585
If the coff timestamp is set to a hash, like lld-link does if /Brepro is
passed, the coff spec suggests that a IMAGE_DEBUG_TYPE_REPRO entry is in the
debug directory. This lets lld-link write such a section.
Fixes PR38429, see bug for details.
Differential Revision: https://reviews.llvm.org/D51652
llvm-svn: 341486
When building a shared libc++.dll, it pulls in libc++abi.a statically
with the --wholearchive flag. If such a build is done with
--export-all-symbols, it's reasonable to assume that everything
from that library also should be exported with the same rules as normal
local object files, even though we normally avoid autoexporting things
from libc++abi.a in other cases when linking a DLL (user code).
Differential Revision: https://reviews.llvm.org/D51529
llvm-svn: 341403
This patch moves the checking for too large offsets into merge sections
earlier.
Without this change the large offset generated in the added test-case
will cause an assert (as it happens to be a value reserved as a
"tombstone" in the DenseMap implementation) when OffsetMap is queried in
getSectionPiece().
To simplify the code and avoid future mistakes I have refactored so that
there is only one function that looks up offsets in the OffsetMap.
Differential Revision: https://reviews.llvm.org/D51180
llvm-svn: 341206
After fixing up the runtime pseudo relocation, the .refptr.<var>
will be a plain pointer with the same value as the IAT entry itself.
To save a little binary size and reduce the number of runtime pseudo
relocations, redirect references to the IAT entry (via the __imp_<var>
symbol) itself and discard the .refptr.<var> chunk (as long as the
same section chunk doesn't contain anything else than the single
pointer).
As there are now cases for both setting the Live variable to true
and false externally, remove the accessors and setters and just make
the variable public instead.
Differential Revision: https://reviews.llvm.org/D51456
llvm-svn: 341175
Martin Storsjo