Fixes PR46420
Similar to D43307 for non-LTO.
Module-level inline assembly can use .symver to create a symbol with `@` in the name.
For relocatable output, @ should be retained in the symbol name. `@ver` should
not be parsed and dropped.
Reviewed By: grimar, psmith
Differential Revision: https://reviews.llvm.org/D82433
Add support for the 34bit relocation R_PPC64_GOT_PCREL34 for
PC Relative in LLD.
Reviewers: sfertile, MaskRay
Differential Revision: https://reviews.llvm.org/D81948
This is the followup to D77647 which implements handling for the new
R_AARCH64_PLT32 relocation type in lld. This relocation would benefit the
PIC-friendly vtables feature described in D72959.
Differential Revision: https://reviews.llvm.org/D81184
See D59553, https://lists.llvm.org/pipermail/llvm-dev/2020-May/141885.html and
https://sourceware.org/pipermail/binutils/2020-May/111357.html for
extensive discussions on a tombstone value.
See http://www.dwarfstd.org/ShowIssue.php?issue=200609.1
(Reserve an address value for "not present") for a DWARF enhancement proposal.
We resolve such relocations to a tombstone value to indicate that the address is invalid.
This solves several problems (the normal behavior is to resolve the relocation to the addend):
* For an empty function in a collected section, a pair of (0,0) can
terminate .debug_loc and .debug_ranges (as of binutils 2.34, GNU ld
resolves such a relocation to 1 to avoid the .debug_ranges issue)
* If DW_AT_high_pc is sufficiently large, the address range can collide
with a regular code range of low address (https://bugs.llvm.org/show_bug.cgi?id=41124 )
* If a text section is folded into another by ICF, we may leave entries
in multiple CUs claiming ownership of the same range of code, which can
confuse consumers.
* Debug information associated with COMDAT sections can have problems
similar to ICF, but is more complex - thus not addressed by this patch.
For pre-DWARF-v5 .debug_loc and .debug_ranges, a pair of 0 can terminate
entries (invalidating subsequent ranges).
-1 is a reserved value with special meaning (base address selection entry) which can't be used either.
Use -2 instead.
For all other .debug_*, use UINT32_MAX for 32-bit targets and UINT64_MAX
for 64-bit targets. In the code, we intentionally use
`uint64_t tombstone = UINT64_MAX` for 32-bit targets as well: this matches
SignExtend64 as used in `relocateAlloc`. (Actually UINT32_MAX does not work for R_386_32)
Note 0, we only special case `target->symbolicRel` (R_X86_64_64, R_AARCH64_ABS64, R_PPC64_ADDR64), not
short-range absolute relocations (e.g. R_X86_64_32). Only forms like DW_FORM_addr need to be special cased.
They can hold an arbitrary address (must be 64-bit on a 64-bit target). (In theory,
producers can make use of small code model to emit 32-bit relocations. This doesn't seem to be leveraged.)
Note 1, we have to ignore the addend, because we don't want to resolve
DW_AT_low_pc (which may have a non-zero addend) to -1+addend (wrap
around to a low address):
__attribute__((section(".text.x"))) void f1() { }
__attribute__((section(".text.x"))) void f2() { } // DW_AT_low_pc has a non-zero addend
Note 2, if the prevailing copy does not have debugging information while
a non-prevailing copy has (partial debug build), we don't do extra work
to attach debugging information to the prevailing definition. (clang
has a lot of debug info optimizations that are on-by-default that assume
the whole program is built with debug info).
clang -c -ffunction-sections a.cc # prevailing copy has no debug info
clang -c -ffunction-sections -g b.cc
Reviewed By: dblaikie, avl, jhenderson
Differential Revision: https://reviews.llvm.org/D81784
Summary:
There were a few issues with the previous setup:
1. The section sorting comparator used a declarative map of section names to
determine the correct order, but it turns out we need to match on more than
just names -- in particular, an upcoming diff will sort based on whether the
S_ZERO_FILL flag is set. This diff changes the sorter to a more imperative but
flexible form.
2. We were sorting OutputSections stored in a MapVector, which left the
MapVector in an inconsistent state -- the wrong keys map to the wrong values!
In practice, we weren't doing key lookups (only container iteration) after the
sort, so this was fine, but it was still a dubious state of affairs. This diff
copies the OutputSections to a vector before sorting them.
3. We were adding unneeded OutputSections to OutputSegments and then filtering
them out later, which meant that we had to remember whether an OutputSegment
was in a pre- or post-filtered state. This diff only adds the sections to the
segments if they are needed.
In addition to those major changes, two minor ones worth noting:
1. I renamed all OutputSection variable names to `osec`, to parallel `isec`.
Previously we were using some inconsistent combination of `osec`, `os`, and
`section`.
2. I added a check (and a test) for InputSections with names that clashed with
those of our synthetic OutputSections.
Reviewers: #lld-macho
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D81887
If neither AT(lma) nor AT>lma_region is specified,
D76995 keeps `lmaOffset` (LMA - VMA) if the previous section is in the
default LMA region.
This patch additionally checks that the two sections are in the same
memory region.
Add a test case derived from https://bugs.llvm.org/show_bug.cgi?id=45313
.mdata : AT(0xfb01000) { *(.data); } > TCM
// It is odd to make .bss inherit lmaOffset, because the two sections
// are in different memory regions.
.bss : { *(.bss) } > DDR
With this patch, section VMA/LMA match GNU ld. Note, GNU ld supports
out-of-order (w.r.t sh_offset) sections and places .text and .bss in the
same PT_LOAD. We don't have that behavior.
Reviewed By: grimar
Differential Revision: https://reviews.llvm.org/D81986
Fixes PR46348.
ObjFile<ELFT>::initializeSymbols contains two symbol iteration loops:
```
for each symbol
if non-inheriting && non-local
fill in this->symbols[i]
for each symbol
if local
fill in this->symbols[i]
else
symbol resolution
```
Symbol resolution can trigger a duplicate symbol error which will call
InputSectionBase::getObjMsg to iterate over InputFile::symbols. If a
non-local symbol appears after the non-local symbol being resolved
(violating ELF spec), its `this->symbols[i]` entry has not been filled
in, InputSectionBase::getObjMsg will crash due to
`dyn_cast<Defined>(nullptr)`.
To fix the bug, reorganize the two loops to ensure this->symbols is
complete before symbol resolution. This enforces the invariant:
InputFile::symbols has none null entry when InputFile::getSymbols() is called.
```
for each symbol
if non-inheriting
fill in this->symbols[i]
for each symbol starting from firstGlobal
if non-local
symbol resolution
```
Additionally, move the (non-local symbol in local part of .symtab)
diagnostic from Writer<ELFT>::copyLocalSymbols() to initializeSymbols().
Reviewed By: grimar, jhenderson
Differential Revision: https://reviews.llvm.org/D81988
Some projects use the constructor attribute on functions that also
return values. In this case we just ignore them.
The error was reported in the libgpg-error project that marks
gpg_err_init with the `__constructor__` attribute.
Differential Revision: https://reviews.llvm.org/D81962
This patch adds some missing information to the LF_BUILDINFO which allows for rebuilding an .OBJ without any external dependency but the .OBJ itself (other than the compiler executable).
Some tools need this information to reproduce a build without any knowledge of the build system. The LF_BUILDINFO therefore stores a full path to the compiler, the PWD (which is the CWD at program startup), a relative or absolute path to the TU, and the full CC1 command line. The command line needs to be freestanding (not depend on any environment variable). In the same way, MSVC doesn't store the provided command-line, but an expanded version (somehow their equivalent of CC1) which is also freestanding.
For more information see PR36198 and D43002.
Differential Revision: https://reviews.llvm.org/D80833
Summary:
llvm-mc emits `__bss` sections with an offset of zero, but we weren't expecting
that in our input, so we were copying non-zero data from the start of the file and
putting it in `__bss`, with obviously undesirable runtime results. (It appears that
the kernel will copy those nonzero bytes as long as the offset is nonzero, regardless
of whether S_ZERO_FILL is set.)
I debated on whether to make a special ZeroFillSection -- separate from a
regular InputSection -- but it seemed like too much work for now. But I'm happy
to refactor if anyone feels strongly about having it as a separate class.
Depends on D80857.
Reviewers: ruiu, pcc, MaskRay, smeenai, alexshap, gkm, Ktwu, christylee
Reviewed By: smeenai
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D80859
Summary:
Turns out this case is actually really common -- it happens whenever there's
a reference to an `extern` variable that ends up statically linked.
Depends on D80856.
Reviewers: ruiu, pcc, MaskRay, smeenai, alexshap, gkm, Ktwu, christylee
Reviewed By: smeenai
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D80857
Summary:
As far as I can tell, it's identical to _GOT_LOAD. llvm-mc has the following
comment explaining why _GOT exists:
```
// x86_64 distinguishes movq foo@GOTPCREL so that the linker can
// rewrite the movq to an leaq at link time if the symbol ends up in
// the same linkage unit.
```
Depends on D80855.
Reviewers: ruiu, pcc, MaskRay, smeenai, alexshap, gkm, Ktwu, christylee
Reviewed By: MaskRay, smeenai
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D80856
Summary:
As mentioned in https://reviews.llvm.org/D81326#2093931, I'm not sure it
makes sense to use the default target triple to determine -arch.
Long-term we should probably detect it from the input object files, but
in the meantime it would be nice not to have to add it to all our tests
by using a convenient default.
Reviewers: #lld-macho
Subscribers: arphaman, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D81983
A hasWildcard pattern iterates over symVector, which can be slow when there
are many --export-dynamic-symbol. In optimistic cases, most patterns don't use
a wildcard character. hasWildcard: false can avoid a symbol table iteration.
While here, add two tests using `[` and `?`, respectively.
Summary:
So things work on 32-bit machines. (@vzakhari reported the
breakage starting from D80177).
Reviewers: #lld-macho, vzakhari
Subscribers: llvm-commits, vzakhari
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D81982
This removes the stub library that lld injected to satisfy the
dependency on the libSystem. Now with TBD support, we can provide the
stub library to permit the tests to function properly as they would on a
real system.
Reviewed By: smeenai
Differential Revision: https://reviews.llvm.org/D81418
This is a complete Options.td compiled from ld(1) dated 2018-03-07 and
cross checked with ld64 source code version 512.4 dated 2018-03-18.
This is the first in a series of diffs for argument handling. Follow-ups
will include switch cases for all the new instances of `OPT_foo`, and
parsing/validation of arguments attached to options, e.g., more code
akin to `OPT_platform_version` and associated `parsePlatformVersion()`.
Reviewed By: smeenai
Differential Revision: https://reviews.llvm.org/D80582
This adds 4 new reloc types.
A lot of code that previously assumed any memory or offset values could be contained in a uint32_t (and often truncated results from functions returning 64-bit values) have been upgraded to uint64_t. This is not comprehensive: it is only the values that come in contact with the new relocation values and their dependents.
A new tablegen mapping was added to automatically upgrade loads/stores in the assembler, which otherwise has no way to select for these instructions (since they are indentical other than for the offset immediate). It follows a similar technique to https://reviews.llvm.org/D53307
Differential Revision: https://reviews.llvm.org/D81704
Context: https://github.com/WebAssembly/memory64/blob/master/proposals/memory64/Overview.md
This is just a first step, adding the new instruction variants while keeping the existing 32-bit functionality working.
Some of the basic load/store tests have new wasm64 versions that show that the basics of the target are working.
Further features need implementation, but these will be added in followups to keep things reviewable.
Differential Revision: https://reviews.llvm.org/D80769
Summary:
We should be reading / writing our addends / relocated addresses based on
r_length, and not just based on the type of the relocation. But since only
some r_length values are valid for a given reloc type, I've also added some
validation.
ld64 has code to allow for r_length = 0 in X86_64_RELOC_BRANCH relocs, but I'm
not sure how to create such a relocation...
Reviewed By: smeenai
Differential Revision: https://reviews.llvm.org/D80854
Summary: After {D81326} landed, some tests started failing if they did
not have `-arch` specified. I think one of the reasons happened was due
to the fact that we were taking a reference to a temporary value that
was freed too early. Fixing that got the error to go away on my local
Linux machine.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D81802
This change introduces an LLD switch --thinlto-single-module to allow compiling only a part of the input modules. This is specifically enables:
1. Fast investigating/debugging modules of interest without spending time on compiling unrelated modules.
2. Compiler debug dump with -mllvm -debug-only= for specific modules.
It will be useful for large applications which has 1K+ input modules for thinLTO.
The switch can be combined with `--lto-obj-path=` or `--lto-emit-asm` to obtain intermediate object files or assembly files. So far the module name matching is implemented as a fuzzy name lookup where the modules with name containing the switch value are compiled.
E.g,
Command:
ld.lld main.o thin.a --thinlto-single-module=thin.a --lto-obj-path=single.o
log:
[ThinLTO] Selecting thin.a(thin1.o at 168) to compile
[ThinLTO] Selecting thin.a(thin2.o at 228) to compile
Command:
ld.lld main.o thin.a --thinlto-single-module=thin1.o --lto-obj-path=single.o
log:
[ThinLTO] Selecting thin.a(thin1.o at 168) to compile
Differential Revision: https://reviews.llvm.org/D80406
After D79300, we don't rewrite InputFile::mb to an empty buffer.
In thinLTOCreateEmptyIndexFiles(), we should check LazyObjFile::fetched
as well as checking whether mb is a bitcode, otherwise we would overwrite (path + .thinlto.bc) with an empty index.
Fixes PR45594.
In `ObjFile<ELFT>::initializeSymbols()`, for a defined symbol relative to
a discarded section (due to section group rules), it may have been
inserted as a lazy symbol. We need to demote it to an Undefined to
enable the `discarded section` error happened in a later pass.
Add `LazyObjFile::fetched` (if true) and `ArchiveFile::parsed` (if
false) to represent that there is an ongoing lazy symbol fetch and we
should replace the current lazy symbol with an Undefined, instead of
calling `Symbol::resolve` (`Symbol::resolve` should be called if the lazy
symbol was added by an unrelated archive/lazy object).
As a side result, one small issue in start-lib-comdat.s is now fixed.
The hack motivating D51892 will be unsupported: if
`.gnu.linkonce.t.__i686.get_pc_thunk.bx` in an archive is referenced
by another section, this will likely be errored unless the function is
also defined in a regular object file.
(Bringing back rL330869 would error `undefined symbol` instead of the
more relevant `discarded section`.)
Note, glibc i386's crti.o still works (PR31215), because
`.gnu.linkonce.t.__x86.get_pc_thunk.bx` is in crti.o (one of the first
regular object files in a linker command line).
Reviewed By: psmith
Differential Revision: https://reviews.llvm.org/D79300
Add support to lld to use Text Based API stubs for linking. This is
support is incomplete not filtering out platforms. It also does not
account for architecture specific API handling and potentially does not
correctly handle trees of re-exports with inlined libraries being
treated as direct children of the top level library.
Use the default target triple configured by the user to determine the
default architecture for `ld64.lld`. Stash the architecture in the
configuration as when linking against TBDs, we will need to filter out
the symbols based upon the architecture. Treat the Haswell slice as it
is equivalent to `x86_64` but with the extra Haswell extensions (e.g.
AVX2, FMA3, BMI1, etc). This will make it easier to add new
architectures in the future.
This change also changes the failure mode where an invalid `-arch`
parameter will result in the linker exiting without further processing.
This merges the static and shared library and behaves as if
`-search_paths_first` was specified which is also the default behaviour
on ld64 (and now lld). Unify the paths, and use `llvm::sys::path` to
deal with the path to be truly agnostic to the host.
If both a.a and b.so define foo
```
ld.bfd -u foo a.a b.so # foo is defined
ld.bfd a.a b.so -u foo # foo is defined
ld.bfd -u foo b.so a.a # foo is undefined (provided at runtime by b.so)
ld.bfd b.so a.a -u foo # foo is undefined (provided at runtime by b.so)
```
In all cases we make foo undefined in the output. I tend to think the
GNU ld behavior makes more sense.
* In their model, they have to treat -u as a fake object file with an
undefined symbol before all input files, otherwise the first archive would not be fetched.
* Following their behavior allows us to drop a --warn-backrefs special case.
Reviewed By: psmith
Differential Revision: https://reviews.llvm.org/D81052
This is a very basic static library search addition. This is the pre-Xcode4
behaviour of searching all paths for the shared version before searching for
the static version of the library. This behaviour is supposed to be inverted
with `-search_paths_first` being the default. This adds the library search
with the intention of providing the setup to merge the paths into one path
and making it controllable by `OPT_search_paths_first`.
The LLVM code base already uses C++14, use std::make_unique
to avoid the explicit constructor invocation via new and to avoid
spelling out the type twice.
ld64 provides the `-search_path_firsts` which will search each path in
the library search path order for both `lib[name].dylib`, `lib[name].a`
before moving on (searching all paths for the dylib and then falling
back to the static library if a shared library was not found).
This option has been the default for a long time, but the command line
flag still exists. Ignore it for compatibility.
--no-allow-shlib-undefined (enabled by default when linking an
executable) rejects unresolved references in shared objects.
Users may be confused by the common diagnostics of unresolved symbols in
object files (LLD: "undefined symbol: foo"; GNU ld/gold: "undefined reference to")
Learn from GCC/clang " [-Wfoo]": append the option name to the
diagnostics. Users can find relevant information by searching
"--no-allow-shlib-undefined". It should also be obvious to them that
the positive form --allow-shlib-undefined can suppress the error.
Also downgrade the error to a warning if --noinhibit-exec is used (compatible
with GNU ld and gold).
Reviewed By: grimar, psmith
Differential Revision: https://reviews.llvm.org/D81028
Previously, the SpecificAllocator was a static local in the `make<T>`
function template. Using static locals is nice because they are only
constructed and registered if they are accessed. However, if there are
multiple calls to make<> with different constructor parameters, we would
get multiple static local variable instances. This is undesirable and
leads to extra memory allocations. I noticed there were two sources of
DefinedRegular allocations while checking heap profiles.
My test refactoring in D80217 seems to have caused yaml2obj to emit
unaligned nlist_64 structs, causing ASAN'd lld to be unhappy. I don't
think this is an issue with yaml2obj though -- llvm-mc also seems to
emit unaligned nlist_64s. This diff makes lld able to safely do aligned
reads under ASAN builds while hopefully creating no overhead for regular
builds on architectures that support unaligned reads.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D80414
For consistency.
The no-id-dylib test was originally referencing the Inputs/ folder via a
relative path. Instead of updating that path, I decided to make the test
self-contained.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D80217
That's what ld64 uses for 64-bit targets. I figured it's best to make
this change sooner rather than later since a bunch of our tests are
relying on hardcoded addresses that depend on this value.
Reviewed By: smeenai
Differential Revision: https://reviews.llvm.org/D80177
I considered making a `Target::validate()` method, but I wasn't sure how
I felt about the overhead of doing yet another switch-dispatch on the
relocation type, so I put the validation in `relocateOne` instead...
might be a bit of a micro-optimization, but `relocateOne` does assume
certain things about the relocations it gets, and this error handling
makes that explicit, so it's not a totally unreasonable code
organization.
Reviewed By: smeenai
Differential Revision: https://reviews.llvm.org/D80049
MIPS 64-bit ABI does not provide special PC-relative relocation like
R_MIPS_PC32 in 32-bit case. But we can use a "chain of relocation"
defined by N64 ABIs. In that case one relocation record might contain up
to three relocations which applied sequentially. Width of a final relocation
mask applied to the result of relocation depends on the last relocation
in the chain. In case of 64-bit PC-relative relocation we need the following
chain: `R_MIPS_PC32 | R_MIPS_64`. The first relocation calculates an
offset, but does not truncate the result. The second relocation just
apply calculated result as a 64-bit value.
The 64-bit PC-relative relocation might be useful in generation of
`.eh_frame` sections to escape passing `-Wl,-z,notext` flags to linker.
Differential Revision: https://reviews.llvm.org/D80390
This patch adds clang options:
-fbasic-block-sections={all,<filename>,labels,none} and
-funique-basic-block-section-names.
LLVM Support for basic block sections is already enabled.
+ -fbasic-block-sections={all, <file>, labels, none} : Enables/Disables basic
block sections for all or a subset of basic blocks. "labels" only enables
basic block symbols.
+ -funique-basic-block-section-names: Enables unique section names for
basic block sections, disabled by default.
Differential Revision: https://reviews.llvm.org/D68049
First, do not reserve numSections in the Chunks array. In cases where
there are many non-prevailing sections, this will overallocate memory
which will not be used.
Second, free the memory for sparseChunks after initializeSymbols. After
that, it is never used.
This saves 50MB of 627MB for my use case without affecting performance.
The inlinees section contains references to the file checksum table. The
file checksum table in the PDB must have the same layout as the file
checksum table in the object file, so all the existing file id
references should stay valid.
Previously, we would do this:
for all inlined functions:
- lookup filename from checksum and string table
- make that filename absolute
- look up the new file id for that filename up in the new checksum
table
This lead to pdbMakeAbsolute and remove_dots ending up in the hot path.
We should only need to absolutify the source path once, not once every
time we process an inline function from that source file.
This speeds up linking chrome PGO stage 1 net_unittests.exe from 9.203s
to 8.500s (-7.6%). Looking just at time to process symbol records, it
goes from ~2000ms to ~1300ms, which is consistent with the overall
speedup of about 700ms. This will be less noticeable in debug builds,
which have fewer inlined functions records.
GNU ld from binutils 2.35 onwards will likely support
--export-dynamic-symbol but with different semantics.
https://sourceware.org/pipermail/binutils/2020-May/111302.html
Differences:
1. -export-dynamic-symbol is not supported
2. --export-dynamic-symbol takes a glob argument
3. --export-dynamic-symbol can suppress binding the references to the definition within the shared object if (-Bsymbolic or -Bsymbolic-functions)
4. --export-dynamic-symbol does not imply -u
I don't think the first three points can affect any user.
For the fourth point, Not implying -u can lead to some archive members unfetched.
Add -u foo to restore the previous behavior.
Exact semantics:
* -no-pie or -pie: matched non-local defined symbols will be added to the dynamic symbol table.
* -shared: matched non-local STV_DEFAULT symbols will not be bound to definitions within the shared object
even if they would otherwise be due to -Bsymbolic, -Bsymbolic-functions, or --dynamic-list.
Reviewed By: psmith
Differential Revision: https://reviews.llvm.org/D80487
LLD supports both REL and RELA for static relocations, but emits either
of REL and RELA for dynamic relocations. The relocation entry format is
specified by each psABI.
musl ld.so supports both REL and RELA. For such ld.so implementations,
REL (.rel.dyn .rel.plt) has size benefits even if the psABI chooses RELA:
sizeof(Elf64_Rel)=16 < sizeof(Elf64_Rela)=24.
* COPY, GLOB_DAT and J[U]MP_SLOT always have 0 addend. A ld.so
implementation does not need to read the implicit addend.
REL is strictly better.
* A RELATIVE has a non-zero addend. Such relocations can be packed
compactly with the RELR relocation entry format, which is out of scope
of this patch.
* For other dynamic relocation types (e.g. symbolic relocation R_X86_64_64),
a ld.so implementation needs to read the implicit addend. REL may have
minor performance impact, because reading implicit addends forces
random access reads instead of being able to blast out a bunch of
writes while chasing the relocation array.
This patch adds -z rel and -z rela to change the relocation entry format
for dynamic relocations. I have tested that a -z rel produced x86-64
executable works with musl ld.so
-z rela may be useful for debugging purposes on processors whose psABIs
specify REL as the canonical format: addends can be easily read by a tool.
Reviewed By: grimar, mcgrathr
Differential Revision: https://reviews.llvm.org/D80496
Previously in the object format we punted on this and simply wrote
zeros (and didn't include the function in the elem segment). With
this change we write a meaningful value which is the segment
relative table index of the associated function.
This matches the that wasm-ld produces in `-r` mode. This inconsistency
between the output the MC object writer and the wasm-ld object
writer could cause warnings to be emitted when reading back in the
output of `wasm-ld -r`. See:
https://github.com/emscripten-core/emscripten/issues/11217
This only applies to this one relocation type which is only generated
when compiling in PIC mode.
Differential Revision: https://reviews.llvm.org/D80774
When we originally wrote these tests we didn't have a stable and
fleshed out assembly format. Now we do so we should prefer that
over llvm ir for lld tests to avoid including more part of llvm
than necessary in order to run the test.
This change converts just 30 out of about 130 test files. More to
come when I have some more time.
Differential Revision: https://reviews.llvm.org/D80361
Summary:
Count the per-module number of basic blocks when the module summary is computed
and sum them up during Thin LTO indexing.
This is used to estimate the working set size under the partial sample PGO.
This is split off of D79831.
Reviewers: davidxl, espindola
Subscribers: emaste, inglorion, hiraditya, MaskRay, steven_wu, dexonsmith, arphaman, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D80403
In D34993, we discussed and concluded that we should drop `__real_
symbol from the symbol table, but I did the opposite in D50569.
This patch is to drop `__real_` symbol.
MaskRay's note: omitting `__real_` is important if it is undefined:
otherwise a subsequent link may error due to the undefined `__real_` in .dynsym
Differential Revision: https://reviews.llvm.org/D51283
Bazel created interface shared objects (.ifso) may be misaligned. We use
llvm::support::detail::packed_endian_specific_integral under the hood
which allows reading of misaligned values, so there is not a need to
diagnose (in LLD we don't intend to support sophisticated parsing for
SHT_GNU_*).
In the 64-bit ELF V2 API Specification: Power Architecture, 2.3.3.1. GPR
Save and Restore Functions defines some special functions which may be
referenced by GCC produced assembly (LLVM does not reference them).
With GCC -Os, when the number of call-saved registers exceeds a certain
threshold, GCC generates `_savegpr0_* _restgpr0_*` calls and expects the
linker to define them. See
https://sourceware.org/pipermail/binutils/2002-February/017444.html and
https://sourceware.org/pipermail/binutils/2004-August/036765.html . This
is weird because libgcc.a would be the natural place. However, the linker
generation approach has the advantage that the linker can generate
multiple copies to avoid long branch thunks. We don't consider the
advantage significant enough to complicate our trunk implementation, so
we take a simple approach.
* Check whether `_savegpr0_{14..31}` are used
* If yes, define needed symbols and add an InputSection with the code sequence.
`_savegpr1_*` `_restgpr0_*` and `_restgpr1_*` are similar.
Reviewed By: sfertile
Differential Revision: https://reviews.llvm.org/D79977
An undefined symbol in a shared object can be versioned, like `f@v1`.
We currently insert `f` as an Undefined into the symbol table, but we
should insert `f@v1` instead.
The string `v1` is inferred from SHT_GNU_versym and SHT_GNU_verneed.
This patch implements the functionality.
Failing to do this can cause two issues:
* If a versioned symbol referenced by a shared object is defined in the
executable, we will fail to export it.
* If a versioned symbol referenced by a shared object in another object
file, --no-allow-shlib-undefined may spuriously report an
"undefined reference to " error. See https://bugs.llvm.org/show_bug.cgi?id=44842
(Linking -lfftw3 -lm on Arch Linux can cause
`undefined reference to __log_finite`)
Reviewed By: grimar
Differential Revision: https://reviews.llvm.org/D80059
Summary:
This patch fixes a bug where initialization code for .bss segments was
emitted in the memory initialization function even though the .bss
segments were discounted in the datacount section and omitted in the
data section. This was producing invalid binaries due to out-of-bounds
segment indices on the memory.init and data.drop instructions that
were trying to operate on the nonexistent .bss segments.
Reviewers: sbc100
Subscribers: dschuff, jgravelle-google, aheejin, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D80354
Summary:
This is a pre-requisite to parallelizing PDB symbol and type merging.
Currently this timer usage would not be thread safe.
Reviewers: aganea, MaskRay
Subscribers: jfb, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D80298
Summary:
This diff restores and builds upon @pcc and @ruiu's initial work on
subsections.
The .subsections_via_symbols directive indicates we can split each
section along symbol boundaries, unless those symbols have been marked
with `.alt_entry`.
We exercise this functionality in our tests by using order files that
rearrange those symbols.
Depends on D79668.
Reviewers: ruiu, pcc, MaskRay, smeenai, alexshap, gkm, Ktwu, christylee
Reviewed By: smeenai
Subscribers: thakis, llvm-commits, pcc, ruiu
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D79926
Note, we still name a preempted SharedSymbol "shared definition",
instead of "reference" as printed by GNU ld. This difference should not matter.
```
// GNU ld
ld.bfd: t: definition of f@v1
ld.bfd: t.so: reference to f@v1
```
Reviewed By: psmith
Differential Revision: https://reviews.llvm.org/D80143
This diff restores and builds upon @pcc and @ruiu's initial work on
subsections.
The .subsections_via_symbols directive indicates we can split each
section along symbol boundaries, unless those symbols have been marked
with `.alt_entry`.
We exercise this functionality in our tests by using order files that
rearrange those symbols.
Reviewed By: smeenai
Differential Revision: https://reviews.llvm.org/D79926
The order file indicates how input sections should be sorted within each
output section, based on the symbols contained within those sections.
This diff sets the stage for implementing and testing
`.subsections_via_symbols`, where we will break up InputSections by each
symbol and sort them more granularly.
Reviewed By: smeenai
Differential Revision: https://reviews.llvm.org/D79668
Under `lld/test/Driver/Inputs/`, all instances of `libtest.a` are
unreferenced. FYI, all of these are empty archives, and the files
contain only a magic number.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D80182
This is fixing a thinLTO module collision issue for thin archives. The problem is that we always use a zero offset to name members in a thin archive and that causes the following build error:
ld.lld: error: Expected at most one ThinLTO module per bitcode file
which happens to a thin archive that has two members with the same object file name (whose paths will be ignored by thinLTO driver)
The fix here is to use real member offset instead as is done for non-thin archives.
Differential Revision: https://reviews.llvm.org/D79880
Announced on https://lists.llvm.org/pipermail/llvm-dev/2020-May/141416.html
Similar to D79371, but for `multiclass B` (convenience helper for defining --foo and --no-foo)
Some changed options are also used by gold, but I haven't seen their
one-dash use cases outside of lld's testsuite.
Fangrui Song