Summary:
Lld test ELF/linkerscript/thunk-gen-mips.s was accidentally disabled due
to the use of wrong FileCheck directives. As a result the test seems to
have bitrotted as it fails to pass if fixing the directive. To ease
updates to the test in case of change of the __start address the checks
have been changed to use numeric variables to express all the addresses
based on the __start address.
Reviewed By: atanasyan
Differential Revision: https://reviews.llvm.org/D79270
This generalizes the main Windows command line tokenizer to be able to
produce StringRef substrings as well as freshly copied C strings. The
implementation is still shared with the normal tokenizer, which is
important, because we have unit tests for that.
.drective sections can be very long. They can potentially list up to
every symbol in the object file by name. It is worth avoiding these
string copies.
This saves a lot of memory when linking chrome.dll with PGO
instrumentation:
BEFORE AFTER % IMP
peak memory: 6657.76MB 4983.54MB -25%
real: 4m30.875s 2m26.250s -46%
The time improvement may not be real, my machine was noisy while running
this, but that the peak memory usage improvement should be real.
This change may also help apps that heavily use dllexport annotations,
because those also use linker directives in object files. Apps that do
not use many directives are unlikely to be affected.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D79262
Summary: Similar to other formats, input sections in the MachO
implementation are now grouped under output sections. This is primarily
a refactor, although there's some new logic (like resolving the output
section's flags based on its inputs).
Differential Revision: https://reviews.llvm.org/D77893
This change add support for defined wasm globals in the .s format,
the MC layer, and wasm-ld
Currently there is no support custom initialization and all wasm
globals are initialized to zero.
Fixes: PR45742
Differential Revision: https://reviews.llvm.org/D79137
Lld test ELF/linkerscript/input-archive.s fails when path contain a @
because is not accepted in unquoted token in linker scripts which leads
to the path being broken in 2 around the @. This commit quotes the path
used in the linker script created by this and similar testcases allowing
the test to pass even in the presence of an @ sign in the path.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D79103
The current implementation assumes that R_PPC64_TOC16_HA is always followed
by R_PPC64_TOC16_LO_DS. This can break with R_PPC64_TOC16_LO:
// Load the address of the TOC entry, instead of the value stored at that address
addis 3, 2, .LC0@tloc@ha # R_PPC64_TOC16_HA
addi 3, 3, .LC0@tloc@l # R_PPC64_TOC16_LO
blr
which is used by boringssl's util/fipstools/delocate/delocate.go
https://github.com/google/boringssl/blob/master/crypto/fipsmodule/FIPS.md has some documentation.
In short, this tool converts an assembly file to avoid any potential relocations.
The distance to an input .toc is not a constant after linking, so it cannot use an `addis;ld` pair.
Instead, it jumps to a stub which loads the TOC entry address with `addis;addi`.
This patch checks the presence of R_PPC64_TOC16_LO and suppresses
toc-indirect to toc-relative relaxation if R_PPC64_TOC16_LO is seen.
This approach is conservative and loses some relaxation opportunities but is easy to implement.
addis 3, 2, .LC0@toc@ha # no relaxation
addi 3, 3, .LC0@toc@l # no relaxation
li 9, 0
addis 4, 2, .LC0@toc@ha # can relax but suppressed
ld 4, .LC0@toc@l(4) # can relax but suppressed
Also note that interleaved R_PPC64_TOC16_HA and R_PPC64_TOC16_LO_DS is
possible and this patch accounts for that.
addis 3, 2, .LC1@toc@ha # can relax
addis 4, 2, .LC2@toc@ha # can relax
ld 3, .LC1@toc@l(3) # can relax
ld 4, .LC2@toc@l(4) # can relax
Reviewed By: #powerpc, sfertile
Differential Revision: https://reviews.llvm.org/D78431
gold has an option --print-symbol-counts= which prints:
// For each archive
archive $archive $members $fetched_members
// For each object file
symbols $object $defined_symbols $used_defined_symbols
In most cases, `$defined_symbols = $used_defined_symbols` unless weak
symbols are present. Strangely `$used_defined_symbols` includes symbols defined relative to --gc-sections discarded sections.
The `symbols` lines do not appear to be useful.
`archive` lines are useful: `$fetched_members=0` lines correspond to
unused archives. The information can be used to trim dependencies.
This patch implements --print-archive-stats= which prints the number of
members and the number of fetched members for each archive.
Reviewed By: grimar
Differential Revision: https://reviews.llvm.org/D78983
Currently, getVA() returns a virtual address with the assumption that
the ImageBase is zero. As I understand, this is what lld-ELF is doing.
However, under our current design, it seems like an awkward setup --
I'm finding that I have to add and subtract ImageBase in several places
to make things work out.
As such, I think it's simpler to have getVA() return a non-relative VA,
but I'm not sure if I'm missing something. Would love to hear more from
folks familiar with lld-ELF.
Differential Revision: https://reviews.llvm.org/D78168
Build the trie by performing a three-way radix quicksort: We start by
sorting the strings by their first characters, then sort the strings
with the same first characters by their second characters, and so on
recursively. Each time the prefixes diverge, we add a node to the trie.
Thanks to @ruiu for the idea.
I used llvm-mc's radix quicksort implementation as a starting point. The
trie offset fixpoint code was taken from
MachONormalizedFileBinaryWriter.cpp.
Differential Revision: https://reviews.llvm.org/D76977
--gdb-index currently crashes when reading a translation unit with
DWARF v5 .debug_loclists . Call stack:
```
SyntheticSections.cpp GdbIndexSection::create
SyntheticSections.cpp readAddressAreas
DWARFUnit.cpp DWARFUnit::tryExtractDIEsIfNeeded
DWARFListTable.cpp DWARFListTableHeader::extract
...
DWARFDataExtractor.cpp DWARFDataExtractor::getRelocatedValue
lld/ELF/DWARF.cpp LLDDwarfObj<ELFT>::find (sec.sec is nullptr)
...
```
This patch adds support for .debug_loclists to make `DWARFUnit::tryExtractDIEsIfNeeded` happy.
Building --gdb-index does not need .debug_loclists
Reviewed By: dblaikie, grimar
Differential Revision: https://reviews.llvm.org/D79061
Drops the behavior from rL217112.
Use the Gnu driver mode by default for all platforms when ld is
invoked. Other names for the program (such as link or ld64) continue
working as before.
Reviewed By: MaskRay, srhines, smeenai, ruiu
Differential Revision: https://reviews.llvm.org/D78837
Summary:
Use the Gnu driver mode by default for all platforms when ld is
invoked. Other names for the program (such as link or ld64) continue
working as before.
Reviewers: MaskRay, int3, srhines, smeenai, ruiu
Reviewed By: MaskRay, srhines, smeenai, ruiu
Subscribers: smeenai, srhines, nickdesaulniers, llvm-commits
Tags: #lld, #llvm
Differential Revision: https://reviews.llvm.org/D78837
This reverts commit 03ffe58605.
Full tile of reverted commit is:
[ELF][PPC64] Don't perform toc-indirect to toc-relative relaxation for
R_PPC64_TOC16_HA not followed by R_PPC64_TOC16_LO_DS
Breaks the multistage lld PowerPC buildbot.
This diff implements basic support for writing a symbol table.
Attributes are loosely supported for extern symbols and not at all for
other types.
Initial version by Kellie Medlin <kelliem@fb.com>
Originally committed in a3d95a50ee and reverted in fbae153ca5 due to
UBSAN erroring over unaligned writes. That has been fixed in the
current diff with the following changes:
```
diff --git a/lld/MachO/SyntheticSections.cpp b/lld/MachO/SyntheticSections.cpp
--- a/lld/MachO/SyntheticSections.cpp
+++ b/lld/MachO/SyntheticSections.cpp
@@ -133,6 +133,9 @@ SymtabSection::SymtabSection(StringTableSection &stringTableSection)
: stringTableSection(stringTableSection) {
segname = segment_names::linkEdit;
name = section_names::symbolTable;
+ // TODO: When we introduce the SyntheticSections superclass, we should make
+ // all synthetic sections aligned to WordSize by default.
+ align = WordSize;
}
size_t SymtabSection::getSize() const {
diff --git a/lld/MachO/Writer.cpp b/lld/MachO/Writer.cpp
--- a/lld/MachO/Writer.cpp
+++ b/lld/MachO/Writer.cpp
@@ -371,6 +371,7 @@ void Writer::assignAddresses(OutputSegment *seg) {
ArrayRef<InputSection *> sections = p.second;
for (InputSection *isec : sections) {
addr = alignTo(addr, isec->align);
+ // We must align the file offsets too to avoid misaligned writes of
+ // structs.
+ fileOff = alignTo(fileOff, isec->align);
isec->addr = addr;
addr += isec->getSize();
fileOff += isec->getFileSize();
@@ -396,6 +397,7 @@ void Writer::writeSections() {
uint64_t fileOff = seg->fileOff;
for (auto § : seg->getSections()) {
for (InputSection *isec : sect.second) {
+ fileOff = alignTo(fileOff, isec->align);
isec->writeTo(buf + fileOff);
fileOff += isec->getFileSize();
}
```
I don't think it's easy to write a test for alignment (that doesn't
involve brittly hard-coding file offsets), so there isn't one... but
UBSAN builds pass now.
Differential Revision: https://reviews.llvm.org/D79050
The current implementation assumes that R_PPC64_TOC16_HA is always followed
by R_PPC64_TOC16_LO_DS. This can break with:
// Load the address of the TOC entry, instead of the value stored at that address
addis 3, 2, .LC0@tloc@ha # R_PPC64_TOC16_HA
addi 3, 3, .LC0@tloc@l # R_PPC64_TOC16_LO
blr
which is used by boringssl's util/fipstools/delocate/delocate.go
https://github.com/google/boringssl/blob/master/crypto/fipsmodule/FIPS.md has some documentation.
In short, this tool converts an assembly file to avoid any potential relocations.
The distance to an input .toc is not a constant after linking, so the assembly cannot use an `addis;ld` pair.
Instead, delocate changes the code to jump to a stub (`addis;addi`) which loads the TOC entry address.
Reviewed By: sfertile
Differential Revision: https://reviews.llvm.org/D78431
This speeds up linking chrome.dll with PGO instrumentation by 13%
(154271ms -> 134033ms).
LLVM's Option library is very slow. In particular, it allocates at least
one large-ish heap object (Arg) for every argument. When PGO
instrumentation is enabled, all the __profd_* symbols are added to the
@llvm.used list, which compiles down to these /INCLUDE: directives. This
means we have O(#symbols) directives to parse in the section, so we end
up allocating an Arg for every function symbol in the object file. This
is unnecessary.
To address the issue and speed up the link, extend the fast path that we
already have for /EXPORT:, which has similar scaling issues.
I promise that I took a hard look at optimizing the Option library, but
its data structures are very general and would need a lot of cleanup. We
have accumulated lots of optional features (option groups, aliases,
multiple values) over the years, and these are now properties of every
parsed argument, when the vast majority of arguments do not use these
features.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D78845
This is primarily motivated by the desire to move from Python2 to
Python3. `PYTHON_EXECUTABLE` is ambiguous. This explicitly identifies
the python interpreter in use. Since the LLVM build seems to be able to
completed successfully with python3, use that across the build. The old
path aliases `PYTHON_EXECUTABLE` to be treated as Python3.
GNU tools generate mapping symbols "$d" for .ARM.exidx sections. The
symbols are added to the symbol table much earlier than the merging
takes place, and after that, they become dangling. Before the patch,
LLD output those symbols as SHN_ABS with the value of 0. The patch
removes such symbols from the symbol table.
Differential Revision: https://reviews.llvm.org/D78820
Summary:
Add logic for emitting the correct set of load commands and segments
when `-dylib` is passed.
I haven't gotten to implementing a real export trie yet, so we can only
emit a single symbol, but it's enough to replace the YAML test files
introduced in D76252.
Differential Revision: https://reviews.llvm.org/D76908
This diff implements basic support for writing a symbol table.
- Attributes are loosely supported for extern symbols and not at all for
other types
Immediate future work will involve implementing section merging.
Initial version by Kellie Medlin <kelliem@fb.com>
Differential Revision: https://reviews.llvm.org/D76742
Previously, the special segments `__PAGEZERO` and `__LINKEDIT` were
implemented as special LoadCommands. This diff implements them using
special sections instead which have an `isHidden()` attribute. We do not
emit section headers for hidden sections, but we use their addresses and
file offsets to determine that of their containing segments. In addition
to allowing us to share more segment-related code, this refactor is also
important for the next step of emitting dylibs:
1) dylibs don't have segments like __PAGEZERO, so we need an easy way of
omitting them w/o messing up segment indices
2) Unlike the kernel, which is happy to run an executable with
out-of-order segments, dyld requires dylibs to have their segment
load commands arranged in increasing address order. The refactor
makes it easier to implement sorting of sections and segments.
Differential Revision: https://reviews.llvm.org/D76839
Summary: The switch --plugin-opt=emit-asm can be used with the gold linker to dump the final assembly code generated by LTO in a user-friendly way. Unfortunately it doesn't work with lld. I'm hooking it up with lld. With that switch, lld emits assembly code into the output file (specified by -o) and if there are multiple input files, each of their assembly code will be emitted into a separate file named by suffixing the output file name with a unique number, respectively. The linking then stops after generating those assembly files.
Reviewers: espindola, wenlei, tejohnson, MaskRay, grimar
Reviewed By: tejohnson, MaskRay, grimar
Subscribers: pcc, emaste, inglorion, arichardson, hiraditya, MaskRay, steven_wu, dexonsmith, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77231
These stub new function were not being added to the symbol table
which in turn meant that we were crashing when trying to output
relocations against them.
Differential Revision: https://reviews.llvm.org/D78779
When discarding local symbols with --discard-all or --discard-locals,
the ones which are used in relocations should be preserved. LLD used
the simplest approach and just ignored those switches when -r or
--emit-relocs was specified.
The patch implements handling the --discard-* switches for the cases
when relocations are kept by identifying used local symbols and allowing
removing only unused ones. This makes the behavior of LLD compatible
with GNU linkers.
Differential Revision: https://reviews.llvm.org/D77807
Fixed error detected by msan. The size field of the .ARM.exidx synthetic
section needs to be initialized to at least estimation level before
calling assignAddresses as that will use the size field.
This was previously reverted in 1ca16fc4f5.
Differential Revision: https://reviews.llvm.org/D78422
This reverts commit f969c2aa65.
There are some msan buildbot failures sanitzer-x86_64-linux-fast that
I need to investigate.
Differential Revision: https://reviews.llvm.org/D78422
The contents of the .ARM.exidx section must be ordered by SHF_LINK_ORDER
rules. We don't need to know the precise address for this order, but we
do need to know the relative order of sections. We have been using the
sectionIndex for this purpose, this works when the OutputSection order
has a monotonically increasing virtual address, but it is possible to
write a linker script with non-monotonically increasing virtual address.
For these cases we need to evaluate the base address of the OutputSection
so that we can order the .ARM.exidx sections properly.
This change moves the finalisation of .ARM.exidx till after the first
call to AssignAddresses. This permits us to sort on virtual address which
is linker script safe. It also permits a fix for part of pr44824 where
we generate .ARM.exidx section for the vector table when that table is so
far away it is out of range of the .ARM.exidx section. This fix will come
in a follow up patch.
Differential Revision: https://reviews.llvm.org/D78422
Time profiler emits relative timestamps for events (the number of
microseconds passed since the start of the current process).
This patch allows combining events from different processes while
preserving their relative timing by emitting a new attribute
"beginningOfTime". This attribute contains the system time that
corresponds to the zero timestamp of the time profiler.
This has at least two use cases:
- Build systems can use this to merge time traces from multiple compiler
invocations and generate statistics for the whole build. Tools like
ClangBuildAnalyzer could also leverage this feature.
- Compilers that use LLVM as their backend by invoking llc/opt in
a child process. If such a compiler supports generating time traces
of its own events, it could merge those events with LLVM-specific
events received from llc/opt, and produce a more complete time trace.
A proof-of-concept script that merges multiple logs that
contain a synchronization point into one log:
https://github.com/broadwaylamb/merge_trace_events
Differential Revision: https://reviews.llvm.org/D78030
For a relative path in INPUT() or GROUP(), this patch changes the search order by adding the directory of the current linker script.
The new search order (consistent with GNU ld >= 2.35 regarding the new test `test/ELF/input-relative.s`):
1. the directory of the current linker script (GNU ld from Binutils 2.35 onwards; https://sourceware.org/bugzilla/show_bug.cgi?id=25806)
2. the current working directory
3. library paths (-L)
This behavior makes it convenient to replace a .so or .a with a linker script with additional input. For example, glibc
```
% cat /usr/lib/x86_64-linux-gnu/libm.a
/* GNU ld script
*/
OUTPUT_FORMAT(elf64-x86-64)
GROUP ( /usr/lib/x86_64-linux-gnu/libm-2.29.a /usr/lib/x86_64-linux-gnu/libmvec.a )
```
could be simplified as `GROUP(libm-2.29.a libmvec.a)`.
Another example is to make libc++.a a linker script:
```
INPUT(libc++.a.1 libc++abi.a)
```
Note, -l is not affected.
Reviewed By: psmith
Differential Revision: https://reviews.llvm.org/D77779
After D78301 MC no longer emits a relocation for this case. Change to use
.inst and .reloc to synthesize the same instruction and relocation. One
more test case I missed.
If there is no SHF_TLS section, there will be no PT_TLS and Out::tlsPhdr may be a nullptr.
If the symbol referenced by an R_TLS is lazy, we should treat the symbol as undefined.
Also reorganize tls-in-archive.s and tls-weak-undef.s . They do not test what they intended to test.
This diff implements:
* dylib loading (much of which is being restored from @pcc and @ruiu's
original work)
* The GOT_LOAD relocation, which allows us to load non-lazy dylib
symbols
* Basic bind opcode emission, which tells `dyld` how to populate the GOT
Differential Revision: https://reviews.llvm.org/D76252
This fixes a bug as exposed by D77807.
Add tests for {--emit-relocs,-r} x {--discard-locals,--discard-all}. They add coverage for previously undertested cases:
* STT_SECTION associated to GCed sections (`gc`)
* STT_SECTION associated to retained sections (`text`)
* STT_SECTION associated to non-SHF_ALLOC sections (`.comment`)
* STB_LOCAL in GCed sections (`unused_gc`)
Reviewed By: grimar, ikudrin
Differential Revision: https://reviews.llvm.org/D78389
D13550 added the diagnostic to address/work around a crash.
The rule was refined by D19836 (test/ELF/tls-archive.s) to exclude Lazy symbols.
https://bugs.llvm.org/show_bug.cgi?id=45598 reported another case where the current logic has a false positive:
Bitcode does not record undefined module-level inline assembly symbols
(`IRSymtab.cpp:Builder::addSymbol`). Such an undefined symbol does not
have the FB_tls bit and lld will not consider it STT_TLS. When the symbol is
later replaced by a STT_TLS Defined, lld will error "TLS attribute mismatch".
This patch fixes this false positive by allowing a STT_NOTYPE undefined
symbol to be replaced by a STT_TLS.
Considered alternative:
Moving the diagnostics to scanRelocs() can improve the diagnostics (PR36049)
but that requires a fair amount of refactoring. We will need more
RelExpr members. It requires more thoughts whether it is worthwhile.
See `test/ELF/tls-mismatch.s` for behavior differences. We will fail to
diagnose a likely runtime bug (STT_NOTYPE non-TLS relocation referencing
a TLS definition). This is probably acceptable because compiler
generated code sets symbol types properly.
Reviewed By: grimar, psmith
Differential Revision: https://reviews.llvm.org/D78438
D77522 changed --warn-backrefs to not warn for linking sandwich
problems (-ldef1 -lref -ldef2). This removed lots of false positives.
However, glibc still has some problems. libc.a defines some symbols
which are normally in libm.a and libpthread.a, e.g. __isnanl/raise.
For a linking order `-lm -lpthread -lc`, I have seen:
```
// different resolutions: GNU ld/gold select libc.a(s_isnan.o) as the definition
backward reference detected: __isnanl in libc.a(printf_fp.o) refers to libm.a(m_isnanl.o)
// different resolutions: GNU ld/gold select libc.a(raise.o) as the definition
backward reference detected: raise in libc.a(abort.o) refers to libpthread.a(pt-raise.o)
```
To facilitate deployment of --warn-backrefs, add --warn-backrefs-exclude= so that
certain known issues (which may be impractical to fix) can be whitelisted.
Deliberate choices:
* Not a comma-separated list (`--warn-backrefs-exclude=liba.a,libb.a`).
-Wl, splits the argument at commas, so we cannot use commas.
--export-dynamic-symbol is similar.
* Not in the style of `--warn-backrefs='*' --warn-backrefs=-liba.a`.
We just need exclusion, not inclusion. For easier build system
integration, we should avoid order dependency. With the current
scheme, we enable --warn-backrefs, and indivial libraries can add
--warn-backrefs-exclude=<glob> to their LDFLAGS.
Reviewed By: psmith
Differential Revision: https://reviews.llvm.org/D77512
See http://lists.llvm.org/pipermail/llvm-dev/2020-April/140549.html
For the record, GNU ld changed to 64k max page size in 2014
https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=7572ca8989ead4c3425a1500bc241eaaeffa2c89
"[RFC] ld/ARM: Increase maximum page size to 64kB"
Android driver forced 4k page size in AArch64 (D55029) and ARM (D77746).
A binary linked with max-page-size=4096 does not run on a system with a
higher page size configured. There are some systems out there that do
this and it leads to the binary getting `Killed!` by the kernel.
In the non-linker-script cases, when linked with -z noseparate-code
(default), the max-page-size increase should not cause any size
difference. There may be some VMA usage differences, though.
Reviewed By: psmith, MaskRay
Differential Revision: https://reviews.llvm.org/D77330
Use the unique filenames that are used when /lldsavetemps is passed.
After this change, module names for LTO blobs in PDBs will be unique.
Visual Studio and probably other debuggers expect module names to be
unique.
Revert some changes from 1e0b158db (2017) that are no longer necessary
after removing MSVC LTO support.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D78221
Implemented a bunch of relocations found in binaries with medium/large code model and the Local-Exec TLS model. The binaries link and run fine in Qemu.
In addition, the emulation `elf64_sparc` is now recognized.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D77672
GCC collect2 passes several options to the linker even if LTO is not used
(note, lld does not support GCC LTO). The lto-wrapper may be a relative
path (especially during development, when gcc is in a build directory), e.g.
-plugin-opt=relative/path/to/lto-wrapper
We need to ignore such options, which are currently interpreted by
cl::ParseCommandLineOptions() and will fail with `error: --plugin-opt: ld.lld: Unknown command line argument 'relative/path/to/lto-wrapper'`
because the path is apparently not an option registered by an `llvm:🆑:opt`.
See lto-plugin-ignore.s for how we interpret various -plugin-opt= options now.
Reviewed By: grimar, tejohnson
Differential Revision: https://reviews.llvm.org/D78158
This should make both static and dynamic NewPM plugins work with LTO.
And as a bonus, it makes static linking of OldPM plugins more reliable
for plugins with both an OldPM and NewPM interface.
I only implemented the command-line flag to specify NewPM plugins in
llvm-lto2, to show it works. Support can be added for other tools later.
Differential Revision: https://reviews.llvm.org/D76866
Summary:
wasm-ld requires --shared-memory to be passed when the atomics feature
is enabled because historically atomic operations were only valid with
shared memories. This change relaxes that requirement for when
building relocatable objects because their memories are not
meaningful. This technically maintains the validity of object files
because the threads spec now allows atomic operations with unshared
memories, although we don't support that elsewhere in the tools yet.
This fixes and Emscripten build issue reported at
https://bugs.chromium.org/p/webp/issues/detail?id=463.
Reviewers: sbc100
Subscribers: dschuff, jgravelle-google, aheejin, sunfish, jfb, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D78072
It can be used to avoid passing the begin and end of a range.
This makes the code shorter and it is consistent with another
wrappers we already have.
Differential revision: https://reviews.llvm.org/D78016
The alignment of ARM64 range extension thunks was fixed in
7c81649219, but ARM range extension thunks, and import
and delay import thunks also need aligning (like all code on ARM
platforms).
I'm adding a test for alignment of ARM64 import thunks - not
specifically adding tests for misalignment of all of them though.
Differential Revision: https://reviews.llvm.org/D77796
Summary:
A previous change (53211a) had updated the argument parsing to handle
large max memories, but 4294967296 would still wrap to zero after the
options were parsed. This change updates the configuration to use a
64-bit integer to store the max memory to avoid that overflow.
Reviewers: sbc100
Subscribers: dschuff, jgravelle-google, aheejin, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77437
This patch changes the reproduce tests so that they no longer extract
the "long" paths of the generated reproduce tar archives. This
extraction prevented them from being run on Windows due to potential
issues relating to the Windows path length limit.
This patch also reduces the use of diff in these tests, as this was
raised as a performance concern in review D77659 and deemed unnecessary.
Differential Revision: https://reviews.llvm.org/D77750
The R_ARM_ALU_PC_G0 and R_ARM_LDR_PC_G0 relocations are used by the
ADR and LDR pseudo instructions, and are the basis of the group
relocations that can load an arbitrary constant via a series of add, sub
and ldr instructions.
The relocations need to be obtained via the .reloc directive.
R_ARM_ALU_PC_G0 is much more complicated as the add/sub instruction uses
a modified immediate encoding of an 8-bit immediate rotated right by an
even 4-bit field. This means that the range of representable immediates
is sparse. We extract the encoding and decoding functions for the modified
immediate from llvm/lib/Target/ARM/MCTargetDesc/ARMAddressingModes.h as
this header file is not accessible from LLD. Duplication of code isn't
ideal, but as these are well-defined mathematical functions they are
unlikely to change.
Differential Revision: https://reviews.llvm.org/D75349
Summary:
/PDBSTREAM:<name>=<file> adds the contents of <file> to stream <name> in the resulting PDB.
This allows native uses with workflows that (for example) add srcsrv streams to PDB files to provide a location for the build's source files.
Results should be equivalent to linking with lld-link, then running Microsoft's pdbstr tool with the command line:
pdbstr.exe -w -p:<PDB LOCATION> -s:<name> -i:<file>
except in cases where the named stream overlaps with a default named stream, such as "/names". In those cases, the added stream will be overridden, making the /pdbstream option a no-op.
Reviewers: thakis, rnk
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D77310
This is an alternative design to D77512.
D45195 added --warn-backrefs to detect
* A. certain input orders which GNU ld either errors ("undefined reference")
or has different resolution semantics
* B. (byproduct) some latent multiple definition problems (-ldef1 -lref -ldef2) which I
call "linking sandwich problems". def2 may or may not be the same as def1.
When an archive appears more than once (-ldef -lref -ldef), lld and GNU
ld may have the same resolution but --warn-backrefs may warn. This is
not uncommon. For example, currently lld itself has such a problem:
```
liblldCommon.a liblldCOFF.a ... liblldCommon.a
_ZN3lld10DWARFCache13getDILineInfoEmm in liblldCOFF.a refers to liblldCommon.a(DWARF.cpp.o)
libLLVMSupport.a also appears twice and has a similar warning
```
glibc has such problems. It is somewhat destined because of its separate
libc/libpthread/... and arbitrary grouping. The situation is getting
improved over time but I have seen:
```
-lc __isnanl references -lm
-lc _IO_funlockfile references -lpthread
```
There are also various issues in interaction with other runtime
libraries such as libgcc_eh and libunwind:
```
-lc __gcc_personality_v0 references -lgcc_eh
-lpthread __gcc_personality_v0 references -lgcc_eh
-lpthread _Unwind_GetCFA references -lunwind
```
These problems are actually benign. We want --warn-backrefs to focus on
its main task A and defer task B (which is also useful) to a more
specific future feature (see gold --detect-odr-violations and
https://bugs.llvm.org/show_bug.cgi?id=43110).
Instead of warning immediately, we store the message and only report it
if no subsequent lazy definition exists.
The use of the static variable `backrefDiags` is similar to `undefs` in
Relocations.cpp
Reviewed By: grimar
Differential Revision: https://reviews.llvm.org/D77522
SymbolAssignment::addr stores the location counter. The type should be
uint64_t instead of unsigned. The upper half of the address space is
commonly used by operating system kernels.
Similarly, SymbolAssignment::size should be an uint64_t. A kernel linker
script can move the location counter from 0 to the upper half of the
address space.
Reviewed By: grimar
Differential Revision: https://reviews.llvm.org/D77445
This is part of the Propeller framework to do post link code layout
optimizations. Please see the RFC here:
https://groups.google.com/forum/#!msg/llvm-dev/ef3mKzAdJ7U/1shV64BYBAAJ and the
detailed RFC doc here:
https://github.com/google/llvm-propeller/blob/plo-dev/Propeller_RFC.pdf
This patch adds lld support for basic block sections and performs relaxations
after the basic blocks have been reordered.
After the linker has reordered the basic block sections according to the
desired sequence, it runs a relaxation pass to optimize jump instructions.
Currently, the compiler emits the long form of all jump instructions. AMD64 ISA
supports variants of jump instructions with one byte offset or a four byte
offset. The compiler generates jump instructions with R_X86_64 32-bit PC
relative relocations. We would like to use a new relocation type for these jump
instructions as it makes it easy and accurate while relaxing these instructions.
The relaxation pass does two things:
First, it deletes all explicit fall-through direct jump instructions between
adjacent basic blocks. This is done by discarding the tail of the basic block
section.
Second, If there are consecutive jump instructions, it checks if the first
conditional jump can be inverted to convert the second into a fall through and
delete the second.
The jump instructions are relaxed by using jump instruction mods, something
like relocations. These are used to modify the opcode of the jump instruction.
Jump instruction mods contain three values, instruction offset, jump type and
size. While writing this jump instruction out to the final binary, the linker
uses the jump instruction mod to determine the opcode and the size of the
modified jump instruction. These mods are required because the input object
files are memory-mapped without write permissions and directly modifying the
object files requires copying these sections. Copying a large number of basic
block sections significantly bloats memory.
Differential Revision: https://reviews.llvm.org/D68065
Fixes https://bugs.llvm.org/show_bug.cgi?id=45391
The LTO code generator happens after version script scanning and may
create references which will fetch some lazy symbols.
Currently a version script does not assign VER_NDX_LOCAL to lazy symbols
and such symbols will be made global after they are fetched.
Change findByVersion and findAllByVersion to work on lazy symbols.
For unfetched lazy symbols, we should keep them non-local (D35263).
Check isDefined() in computeBinding() as a compensation.
This patch fixes a companion bug that --dynamic-list does not export
libcall fetched symbols.
Reviewed By: grimar
Differential Revision: https://reviews.llvm.org/D77280
finalizeSynthetic(in.symTab) calls sortSymTabSymbols() to order local
symbols before non-local symbols.
The newly added tests ensure that thunk symbols are added before
finalizeSynthetic(in.symTab), otherwise .symtab would be out of order.
A PC-relative relocation referencing a non-preemptible absolute symbol
(due to STT_TLS) is not representable in -pie/-shared mode.
Differential Revision: https://reviews.llvm.org/D77021
In the near future llvm-mc will resolve the fixups that generate
R_ARM_THUMB_PC8 and R_ARM_THUMB_PC12 at assembly time (see comments in
D72892), and forbid inter-section references. Change the LLD tests for
these relocations to use .inst and .reloc to avoid LLD tests failing when
this happens. The tests generate the same instructions, relocations
and symbols.
I will need to make equivalent changes for D75349 Arm equivalent
relocations, but this is still in review so these don't need changing
before llvm-mc.
Differential Revision: https://reviews.llvm.org/D77200
The aliased options in the --help output use double dashes. It is
inconsistent to have single-dashed messages. Additionally, -l and -t are
common short options and single-dashed forms prefixed with them can
cause confusion.
In most cases, LLD prints its multiline diagnostic messages starting
additional lines with ">>> ". That greatly helps external tools to parse
the output, simplifying combining several lines of the log back into one
message. The patch fixes the only message I found that does not follow
the common pattern.
Differential Revision: https://reviews.llvm.org/D77132
Thomas Preud'homme