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
Jez Ng