Commit Graph

13458 Commits

Author SHA1 Message Date
Martin Storsjö a54919e0c1 [LLD] [COFF] Error out if creating a DLL with too many exported symbols
The PE/DLL format has a limit on 64k exported symbols per DLL; make
sure to check this.

Differential Revision: https://reviews.llvm.org/D86701
2020-08-31 21:15:13 +03:00
Hubert Tong 97febb139d [LLD][PowerPC][test] Disable ELF/ppc64-pcrel-long-branch-error.s
Following 0becc27ebf, `ppc64-pcrel-long-branch-error.s` fails in some
environments with out-of-memory errors associated with buffering the
output in-memory. Since the alternative of writing to an allocated file
is also known to cause problems, we will disable the test
unconditionally (pending a mechanism to disable the test selectively).
2020-08-29 00:08:52 -04:00
Victor Huang 0becc27ebf [LLD][PowerPC] Remove redundant file write out in the test cases
Fix the time out test failure on lld-x86_64-freebsd build bot.

Peer reviewed by: stefanp, nemanjai
2020-08-28 15:09:17 -05:00
Victor Huang bfc7636612 [LLD][PowerPC] Add a pc-rel based long branch thunk
In this patch, a pc-rel based long branch thunk is added for the local
call protocol that caller and callee does not use TOC.

Reviewed By: sfertile, nemanjai

Differential Revision: https://reviews.llvm.org/D86706
2020-08-28 10:40:48 -05:00
Jez Ng ae8fa1d8a6 [lld-macho][NFC] Define isHidden() in LinkEditSection
Since it's always true

Reviewed By: #lld-macho, smeenai

Differential Revision: https://reviews.llvm.org/D86749
2020-08-27 17:44:18 -07:00
Jez Ng ccbacdded4 [lld-macho] Weak locals should be relaxed too
Reviewed By: #lld-macho, smeenai

Differential Revision: https://reviews.llvm.org/D86746
2020-08-27 17:44:17 -07:00
Jez Ng 0407197711 [lld-macho] Support GOT relocations to __dso_handle
Found such a relocation while testing some real world programs.

Reviewed By: #lld-macho, smeenai

Differential Revision: https://reviews.llvm.org/D86642
2020-08-27 17:44:17 -07:00
Jez Ng 7083363c05 [lld-macho] Implement GOT_LOAD relaxation
We can have GOT_LOAD relocations that reference `__dso_handle`.
However, our binding opcode encoder doesn't support binding to the DSOHandle
symbol. Instead of adding support for that, I decided it would be cleaner to
implement GOT_LOAD relaxation since `__dso_handle`'s location is always
statically known.

Reviewed By: #lld-macho, smeenai

Differential Revision: https://reviews.llvm.org/D86641
2020-08-27 17:44:17 -07:00
Jez Ng 2a38dba7dd [lld-macho] Emit binding opcodes for defined symbols that override weak dysyms
These opcodes tell dyld to coalesce the overridden weak dysyms to this
particular symbol definition.

Reviewed By: #lld-macho, smeenai

Differential Revision: https://reviews.llvm.org/D86575
2020-08-27 17:44:16 -07:00
Jez Ng 3da2130e45 [lld-macho] Emit the right header flags for weak bindings/symbols
Reviewed By: #lld-macho, smeenai

Differential Revision: https://reviews.llvm.org/D86574
2020-08-27 17:44:16 -07:00
Jez Ng e263287c79 [lld-macho] Implement weak binding for branch relocations
Since there is no "weak lazy" lookup, function calls to weak symbols are
always non-lazily bound. We emit both regular non-lazy bindings as well
as weak bindings, in order that the weak bindings may overwrite the
non-lazy bindings if an appropriate symbol is found at runtime. However,
the bound addresses will still be written (non-lazily) into the
LazyPointerSection.

Reviewed By: #lld-macho, smeenai

Differential Revision: https://reviews.llvm.org/D86573
2020-08-27 17:44:15 -07:00
Jez Ng d2b845dd6c [lld-macho] Disable invalid/stub-link.s test for Mac
It seems to be failing on some Google Buildbots.

This diff also includes a minor fix for the install name of one of
libSystem's re-exports. I don't think it's the cause of the test
failure, though. The wrong install name just meant that the symbol
lookup failure would still happen, but it would have been caused by the
re-export not being found, instead of the arch failing to match.

Differential Revision: https://reviews.llvm.org/D86728
2020-08-27 11:24:22 -07:00
Martin Storsjö df8f3bf626 [LLD] [COFF] Check the aux section definition size for IMAGE_COMDAT_SELECT_SAME_SIZE
Binutils generated sections seem to be padded to a multiple of 16 bytes,
but the aux section definition contains the original, unpadded section
length.

The size check used for IMAGE_COMDAT_SELECT_SAME_SIZE previously
only checked the size of the section itself. When checking the
currently processed object file against the previously chosen
comdat section, we easily have access to the aux section definition
of the currently processed section, but we have to iterate over the
symbols of the previously selected object file to find the section
definition of the previously picked section. (We don't want to
inflate SectionChunk to carry more data, for something that is only
needed in corner cases.) Only do this when the mingw flag is set.

This fixes statically linking clang-built C++ object files against
libstdc++ built with GCC, if the object files contain e.g. typeinfo.

Differential Revision: https://reviews.llvm.org/D86659
2020-08-27 15:08:57 +03:00
Martin Storsjö e72403f96d [LLD] [MinGW] Enable dynamicbase by default
This matches lld-link's own default.

Add a new command line option --no-dynamicbase for disabling it.
(Unfortunately, GNU ld doesn't yet have a matching --no-dynamicbase
option, as that's the default there.)

Differential Revision: https://reviews.llvm.org/D86654
2020-08-27 15:08:53 +03:00
Andrew Ng d4e2e2852a [ELF][test] Add test coverage of TLS to gc-sections.s
Differential Revision: https://reviews.llvm.org/D86639
2020-08-27 12:28:51 +01:00
James Henderson d2385f6d2f [lld][ELF][test] Expand testing of symbols in mergeable sections
Whilst reviewing some internal testing, I noticed a couple of holes in
coverage of mergeable sections containing symbols. This patch addresses
these holes:
1) Show that mid-piece symbols have their values updated properly when
   pieces are merged.
2) Show the behaviour of symbols in mergeable pieces when --gc-sections
   is enabled.

Reviewed by: grimar, MaskRay

Differential Revision: https://reviews.llvm.org/D86543
2020-08-27 10:38:42 +01:00
Jez Ng eec3500e50 [lld-macho] Fix objc.s test
Summary: It was passing on my local machine due to previously-written
files cached in the test output folder.
2020-08-26 22:59:31 -07:00
Jez Ng 62b39b3a0c [lld-macho] Implement -all_load
Differential Revision: https://reviews.llvm.org/D86640
2020-08-26 19:21:17 -07:00
Jez Ng cbe27316ef [lld-macho] Implement weak bindings for GOT/TLV
Previously, we were only emitting regular bindings to weak
dynamic symbols; this diff adds support for the weak bindings too, which
can overwrite the regular bindings at runtime. We also treat weak
defined global symbols similarly -- since they can also be interposed at
runtime, they need to be treated as potentially dynamic symbols.

Note that weak bindings differ from regular bindings in that they do not
specify the dylib to do the lookup in (i.e. weak symbol lookup happens
in a flat namespace.)

Differential Revision: https://reviews.llvm.org/D86572
2020-08-26 19:21:09 -07:00
Jez Ng b84d72d893 [lld-macho][NFC] Handle GOT bindings and regular bindings more uniformly
Previously, the BindingEntry struct could only store bindings to offsets
within InputSections. Since the GOTSection and TLVPointerSections are
OutputSections, I handled those in a separate code path. However, this
makes it awkward to support weak bindings properly without code
duplication. This diff allows BindingEntries to point directly to
OutputSections, simplifying the upcoming weak binding implementation.

Along the way, I also converted a bunch of functions taking references
to symbols to take pointers instead. Given how much casting we do for
Symbol (especially in the upcoming weak binding diffs), it's cleaner
this way.

Differential Revision: https://reviews.llvm.org/D86571
2020-08-26 19:21:04 -07:00
Jez Ng cf918c809b [lld-macho] Implement -ObjC
It's roughly like -force_load with some filtering.

Differential Revision: https://reviews.llvm.org/D86181
2020-08-26 19:20:55 -07:00
Jez Ng 7394460d87 [lld-macho] Handle TAPI and regular re-exports uniformly
The re-exports list in a TAPI document can either refer to other inlined
TAPI documents, or to on-disk files (which may themselves be TBD or
regular files.) Similarly, the re-exports of a regular dylib can refer
to a TBD file.

Differential Revision: https://reviews.llvm.org/D85404
2020-08-26 19:20:48 -07:00
Jez Ng 6336c042f6 [lld-macho] Make it possible to re-export .tbd files
Two things needed fixing for that to work:

1. getName() no longer returns null for DylibFiles constructed from TAPIs
2. markSubLibrary() now accepts .tbd as a possible extension

Differential Revision: https://reviews.llvm.org/D86180
2020-08-26 19:20:42 -07:00
Jez Ng 3e7a86e366 [lld-macho] Fall back to raw path if we don't find anything under syslibroot
This matches ld64's behavior

Differential Revision: https://reviews.llvm.org/D85992
2020-08-26 19:20:35 -07:00
Mateusz Mikuła c82078b5d7 [LLD][MinGW] Handle allow-multiple-definition flag
Basically copied from ELF driver.

Differential Revision: https://reviews.llvm.org/D86512
2020-08-26 09:38:11 +03:00
Mateusz Mikuła dcb1ce61b8 [LLD][MinGW] Cleanup Options.td file. NFC.
Based on ELF driver Options.td.

Differential Revision: https://reviews.llvm.org/D86509
2020-08-26 09:38:11 +03:00
Fangrui Song 25863cc512 [ELF] .note.gnu.property: error for invalid pr_datasize
A n_type==NT_GNU_PROPERTY_TYPE_0 note encodes a program property.
If pr_datasize is invalid, LLD may crash
(https://github.com/ClangBuiltLinux/linux/issues/1141)

This patch adds some error checking, supports big-endian, and add some tests
for invalid n_descsz.

Differential Revision: https://reviews.llvm.org/D86422
2020-08-25 08:05:39 -07:00
Georgii Rymar 41726f8d5b [llvm-readobj] - Print "Unknown" when a program header is unknown.
Currently, when a program header type is unknown, we dont print anything:

```
ProgramHeader {
  Type:  (0x60000000)
```

With this patch the output will be:

```
ProgramHeader {
  Type: Unknown (0x60000000)
```

It was discussed in D85526 and consistent with what we print for
'--sections' already, e.g.:

```
Section {
  Name: .sec
  Type: Unknown (0x7FFFFFFF)
}
```

Differential revision: https://reviews.llvm.org/D86213
2020-08-25 13:05:17 +03:00
Pavel Labath 3d1b0000f9 [lld] s/dyn_cast/isa in InputSection.cpp
Avoids a -Wunused-variable with gcc.
2020-08-24 11:45:30 +02:00
Bas Zalmstra 54f5a4ea4c [LLD][COFF] Reset outputSections for successive runs
The global variable outputSections in the COFF writer was not
cleared between runs which caused successive calls to lld::coff::link
to generate invalid binaries. These binaries when loaded would result
in "invalid win32 applications" and/or "bad image" errors.

Differential Revision: https://reviews.llvm.org/D86401
2020-08-22 23:08:43 +03:00
Josh Stone b26b32b5d3 lld: link libatomic if needed for Timer
D80298 made Timer::total atomic, but this requires linking libatomic
on some targets.

Reviewed By: aaronpuchert

Differential Revision: https://reviews.llvm.org/D85691
2020-08-21 17:47:55 -07:00
Stefan Pintilie 0cadd162b7 Forgot to update the test case for ppc64-tls-missing-gdld.s for 02e02f5398 2020-08-21 13:22:01 -05:00
Stefan Pintilie 02e02f5398 [LLD][PowerPC] Add check in LLD to produce an error for missing TLSGD/TLSLD
The function `__tls_get_addr` is used to get the address of an object that is Thread Local Storage.
It needs to have two relocations on it.
One relocation is for the function call itself and it is either R_PPC64_REL24 or R_PPC64_REL24_NOTOC.
The other is R_PPC64_TLSGD or R_PPC64_TLSLD for the symbol that is having its address computed.

In the early days of the transition from the ELFv1 ABI that is used for big endian PowerPC Linux distributions to the ELFv2 ABI that is used for little endian PowerPC Linux distributions, there was some ambiguity in the specification of the relocations for TLS. The GNU linker has implemented support for correct handling of calls to __tls_get_addr with a missing relocation. Unfortunately, we didn't notice that the IBM XL compiler did not handle TLS according to the updated ABI until we tried linking XL compiled libraries with LLD. As a result, there is a lot of code out there in various libraries compiled with XL that have this problem.

This patch adds a new error check in LLD that makes sure calls to `__tls_get_addr` are not missing the TLSGD/TLSLD relocation.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D85994
2020-08-21 12:56:12 -05:00
Fangrui Song 9670029b6b [ELF] Keep st_type for symbol assignment
PR46970: for `alias = aliasee`, the alias can be used in relocation processing
and on ARM st_type does affect Thumb interworking. It is thus desirable for the
alias to get the same st_type.

Note that the st_size field should not be inherited because some tools use
st_size=0 as a heuristic to detect aliases. Retaining st_size can thwart such
heuristics and cause aliases to be preferred over the original symbols.

Differential Revision: https://reviews.llvm.org/D86263
2020-08-20 16:05:27 -07:00
Fangrui Song b587ca93be [test] Replace `yaml2obj >` with `yaml2obj -o` and remove unneeded input redirection 2020-08-20 15:01:09 -07:00
Hans Wennborg 7f00938975 lld docs config: Use a list key in html_sidebars
Otherwise the docs-lld-html target fails to build using recent Sphinx
with the following not very helpful error message:

An error happened in rendering the page index.
Reason: TemplateNotFound()

It turns out the values in the html_sidebars dictionary always need to be lists
now. See https://github.com/sphinx-doc/sphinx/issues/6186
2020-08-20 16:48:06 +02:00
Fangrui Song ac46bc35e9 [ELF][test] Fix some llvm-objdump RUN lines which don't actually test anything 2020-08-19 22:49:04 -07:00
Fangrui Song ec29538af2 [ELF] Assign file offsets of non-SHF_ALLOC after SHF_ALLOC and set sh_addr=0 to non-SHF_ALLOC
* GNU ld places non-SHF_ALLOC sections after SHF_ALLOC sections. This has the
  advantage that the file offsets of a non-SHF_ALLOC cannot be contained in
  a PT_LOAD. This patch matches the behavior.
* For non-SHF_ALLOC non-orphan sections, GNU ld may assign non-zero sh_addr and
  treat them similar to SHT_NOBITS (not advance location counter). This
  is an alternative approach to what we have done in D85100.
  By placing non-SHF_ALLOC sections at the end, we can drop special
  cases in createSection and findOrphanPos added by D85100.

  Different from GNU ld, we set sh_addr to 0 for non-SHF_ALLOC sections. 0
  arguably is better because non-SHF_ALLOC sections don't appear in the memory
  image.

ELF spec says:

> sh_addr - If the section will appear in the memory image of a process, this
> member gives the address at which the section's first byte should
> reside. Otherwise, the member contains 0.

D85100 appeared to take a detour. If we take a combined view on D85100 and this
patch, the overall complexity slightly increases (one more 3-line loop) and
compatibility with GNU ld improves.

The behavior we don't want to match is the special treatment of .symtab
.shstrtab .strtab: they can be matched in LLD but not in GNU ld.

Reviewed By: jhenderson, psmith

Differential Revision: https://reviews.llvm.org/D85867
2020-08-18 09:03:01 -07:00
Alexandre Ganea 98e01f56b0 Revert "Re-Re-land: [CodeView] Add full repro to LF_BUILDINFO record"
This reverts commit a3036b3863.

As requested in: https://reviews.llvm.org/D80833#2221866
Bug report: https://crbug.com/1117026
2020-08-17 15:49:18 -04:00
Fangrui Song e8a11c0558 [ELF] Allow mixed SHF_LINK_ORDER & non-SHF_LINK_ORDER sections and sort within InputSectionDescription
LLD currently does not allow non-contiguous SHF_LINK_ORDER components in an
output section. This makes it infeasible to add SHF_LINK_ORDER to an existing
metadata section if backward compatibility with older object files are
concerned.

We did not allow mixed components (like GNU ld) and D77007 relaxed to allow
non-contiguous SHF_LINK_ORDER components. This patch allows arbitrary mix, with
sorting performed within an InputSectionDescription. For example,
`.rodata : {*(.rodata.foo) *(.rodata.bar)}`, has two InputSectionDescription's.
If there is at least one SHF_LINK_ORDER and at least one non-SHF_LINK_ORDER in
.rodata.foo, they are ordered within `*(.rodata.foo)`: we arbitrarily place
SHF_LINK_ORDER components before non-SHF_LINK_ORDER components (like Solaris ld).

`*(.rodata.bar)` is ordered similarly, but the two InputSectionDescription's
don't interact.  It can be argued that this is more reasonable than the previous
behavior where written order was not respected.

It would be nice if the two different semantics (ordering requirement & garbage
collection) were not overloaded on one section flag, however, it is probably
difficult to obtain a generic flag at this point
(https://groups.google.com/forum/#!topic/generic-abi/hgx_m1aXqUo
"SHF_LINK_ORDER's original semantics make upgrade difficult").

(Actually, without the GC semantics, SHF_LINK_ORDER would still have the
sh_link!=0 & sh_link=0 issue. It is just that people find the GC semantics more
useful and tend to use the feature more often.)

GNU ld feature request: https://sourceware.org/bugzilla/show_bug.cgi?id=16833

Differential Revision: https://reviews.llvm.org/D84001
2020-08-17 11:29:05 -07:00
Fangrui Song 661c089a40 [ELF] Enforce two-dash form for some LLD specific options and the newer --[no-]pcrel-optimize
Since -[no-]toc-optimize has not ever been used, we can enforce the two-dash form as well.
2020-08-17 10:00:31 -07:00
Nemanja Ivanovic cddb0dbcef [LLD][PowerPC] Implement GOT to PC-Rel relaxation
This patch implements the handling for the R_PPC64_PCREL_OPT relocation as well
as the GOT relocation for the associated R_PPC64_GOT_PCREL34 relocation.

On Power10 targets with PC-Relative addressing, the linker can relax
GOT-relative accesses to PC-Relative under some conditions. Since the sequence
consists of a prefixed load, followed by a non-prefixed access (load or store),
the linker needs to replace the first instruction (as the replacement
instruction will be prefixed). The compiler communicates to the linker that
this optimization is safe by placing the two aforementioned relocations on the
GOT load (of the address).
The linker then does two things:

- Convert the load from the got into a PC-Relative add to compute the address
  relative to the PC
- Find the instruction referred to by the second relocation (R_PPC64_PCREL_OPT)
  and replace the first with the PC-Relative version of it

It is important to synchronize the mapping from legacy memory instructions to
their PC-Relative form. Hence, this patch adds a file to be included by both
the compiler and the linker so they're always in agreement.

Differential revision: https://reviews.llvm.org/D84360
2020-08-17 09:36:09 -05:00
Victor Huang 7b391245d8 [PowerPC] Fix thunk alignment issue when using pc-rel instruction
Thunk alignment is added in thie patch when using pc-rel instructions
to avoid crossing the 64 byte boundary.

Patched by: nemanjai, NeHuang
Reviewed By: sfertile, MaskRay

Differential Revision: https://reviews.llvm.org/D85973
2020-08-17 09:09:36 -05:00
Georgii Rymar c135a68d42 [LLD][ELF] - Do not produce an invalid dynamic relocation order with --shuffle-sections.
Normally (when not on android with android relocation packing enabled),
we put IRelative relocations to ".rel[a].dyn", after other relocations,
to ensure that IRelatives are processed last by the dynamic loader.

To achieve that we add the `in.relaIplt` after the `part.relaDyn`:
https://github.com/llvm/llvm-project/blob/master/lld/ELF/Writer.cpp#L540

The problem is that `--shuffle-sections` might break the sections order.
This patch fixes it.

Fixes https://bugs.llvm.org/show_bug.cgi?id=47056.

Differential revision: https://reviews.llvm.org/D85651
2020-08-17 14:46:52 +03:00
Mehdi Amini 22cbe40fa9 Slightly relax the regex on lld version in test (NFC)
This makes the test introduced in 537f5483fe more robust with respect
to the actual version number. The previous regex restricted the version
to start with a leading `1` which was overly restrictive.
2020-08-15 21:38:02 +00:00
Fangrui Song b358daddea [ELF] Re-initialize InputFile::isInGroup so that elf::link can be called more than once 2020-08-14 15:38:41 -07:00
Greg McGary 537f5483fe [lld-macho] Emit load command LC_BUILD_VERSION
Reviewed By: int3

Differential Revision: https://reviews.llvm.org/D85786
2020-08-14 12:36:43 -07:00
Fangrui Song fb141292f4 [ELF] --gdb-index: skip SHF_GROUP .debug_info
-gdwarf-5 -fdebug-types-section may produce multiple .debug_info sections.  All
except one are type units (.debug_types before DWARF v5). When constructing
.gdb_index, we should ignore these type units. We use a simple heuristic: the
compile unit does not have the SHF_GROUP flag. (This needs to be revisited if
people place compile unit .debug_info in COMDAT groups.)

This issue manifests as a data race: because an object file may have multiple
.debug_info sections, we may concurrently construct `LLDDwarfObj` for the same
file in multiple threads. The threads may access `InputSectionBase::data()`
concurrently on the same input section. `InputSectionBase::data()` does a lazy
uncompress() and rewrites the member variable `rawData`. A thread running zlib
`inflate()` (transitively called by uncompress()) on a buffer with `rawData`
tampered by another thread may fail with `uncompress failed: zlib error: Z_DATA_ERROR`.

Even if no data race occurred in an optimistic run, if there are N .debug_info,
one CU entry and its address ranges will be replicated N times. The result
.gdb_index can be much larger than a correct one.

The new test gdb-index-dwarf5-type-unit.s actually has two compile units. This
cannot be produced with regular approaches (it can be produced with -r
--unique). This is used to demonstrate that the .gdb_index construction code
only considers the last non-SHF_GROUP .debug_info

Reviewed By: grimar

Differential Revision: https://reviews.llvm.org/D85579
2020-08-13 09:11:01 -07:00
Fangrui Song 88498f44df [ELF] -r: allow SHT_X86_64_UNWIND to be merged into SHT_PROGBITS
* For .cfi_*, GCC/GNU as emits SHT_PROGBITS type .eh_frame sections.
* Since rL252300, clang emits SHT_X86_64_UNWIND type .eh_frame sections
  (originated from Solaris, documented in the x86-64 psABI).
* Some assembly use `.section .eh_frame,"a",@unwind` to generate
  SHT_X86_64_UNWIND .eh_frame sections.

In a non-relocatable link, input .eh_frame are combined and there is
only one SyntheticSection .eh_frame in the output section, so the
"section type mismatch" diagnostic does not fire.

In a relocatable link, there is no SyntheticSection .eh_frame. .eh_frame of
mixed types can trigger the diagnostic. This patch fixes it by adding another
special case 0x70000001 (= SHT_X86_64_UNWIND) to canMergeToProgbits().

    ld.lld -r gcc.o clang.o => error: section type mismatch for .eh_frame

There was a discussion "RFC: Usefulness of SHT_X86_64_UNWIND" on the x86-64-abi
mailing list. Folks are not wild about making the psABI value 0x70000001 into
gABI, but a few think defining 0x70000001 for .eh_frame may be a good idea for a
new architecture.

Reviewed By: grimar

Differential Revision: https://reviews.llvm.org/D85785
2020-08-13 08:14:45 -07:00
Jez Ng 7d32e6e3f0 [lld-macho] Fix invalid-stub test on Windows, take 2 2020-08-12 22:21:57 -07:00
Jez Ng 11e2c253ac [lld-macho] Try to fix invalid-stub test on Windows
Summary: Path separator issues...
2020-08-12 20:58:47 -07:00
Jez Ng e48d1262b8 [lld-macho] Support -rpath
Pretty straightforward; just emits LC_RPATH for dyld to consume.

Note that lld itself does not yet support dylib lookup via @rpath.

Reviewed By: #lld-macho, compnerd

Differential Revision: https://reviews.llvm.org/D85701
2020-08-12 19:50:28 -07:00
Jez Ng 437e6bd286 [lld-macho] Implement -force_load
It's similar to lld-ELF's `-whole-archive`, but applied to individual
archives instead of to a series of them.

Reviewed By: #lld-macho, smeenai

Differential Revision: https://reviews.llvm.org/D85550
2020-08-12 19:50:27 -07:00
Jez Ng 180ad756ec [lld-macho] Support larger dylib symbol ordinals in bindings
Do folks care if we don't have a test for this? Creating 16
dylibs to trigger this straightforward code path seems a little tedious

Reviewed By: #lld-macho, smeenai

Differential Revision: https://reviews.llvm.org/D85467
2020-08-12 19:50:25 -07:00
Jez Ng c3eb1e2754 [lld-macho] Add error handling for malformed TBD files
Previously, lld would crash while complaining that `Expected<T>
must be checked before access or destruction`.

Reviewed By: #lld-macho, compnerd

Differential Revision: https://reviews.llvm.org/D85403
2020-08-12 19:50:13 -07:00
Jez Ng 7e6d675499 [lld-macho] Avoid unnecessary shared_ptr in DylibFile ctor
DylibFile doesn't store a pointer to its InterfaceFile
parameter, so there's no need to use a shared_ptr.

Reviewed By: #lld-macho, compnerd

Differential Revision: https://reviews.llvm.org/D85402
2020-08-12 19:50:12 -07:00
Jez Ng a499898e86 [lld-macho] Generate ObjC symbols from .tbd files
I followed similar logic in TapiFile.cpp.

Reviewed By: #lld-macho, smeenai

Differential Revision: https://reviews.llvm.org/D85255
2020-08-12 19:50:10 -07:00
Jez Ng 3c9100fb78 [lld-macho] Support dynamic linking of thread-locals
References to symbols in dylibs work very similarly regardless of
whether the symbol is a TLV. The main difference is that we have a
separate `__thread_ptrs` section that acts as the GOT for these
thread-locals.

We can identify thread-locals in dylibs by a flag in their export trie
entries, and we cross-check it with the relocations that refer to them
to ensure that we are not using a GOT relocation to reference a
thread-local (or vice versa).

Reviewed By: #lld-macho, smeenai

Differential Revision: https://reviews.llvm.org/D85081
2020-08-12 19:50:09 -07:00
Samuel Kostial 304264e73d [lld][WebAssembly] Emit all return types of multivalue functions
We previously were incorrectly emitting only the first result type.

Differential Revision: https://reviews.llvm.org/D85783
2020-08-12 13:14:15 -07:00
Wouter van Oortmerssen b52fc59e17 [WebAssembly] Fixed memory.init always using 64-bit ptr
(because the is64 flag was tested incorrectly in LLD).
2020-08-12 12:23:36 -07:00
Petr Hosek 31e5f7120b [CMake] Simplify CMake handling for zlib
Rather than handling zlib handling manually, use find_package from CMake
to find zlib properly. Use this to normalize the LLVM_ENABLE_ZLIB,
HAVE_ZLIB, HAVE_ZLIB_H. Furthermore, require zlib if LLVM_ENABLE_ZLIB is
set to YES, which requires the distributor to explicitly select whether
zlib is enabled or not. This simplifies the CMake handling and usage in
the rest of the tooling.

This is a reland of abb0075 with all followup changes and fixes that
should address issues that were reported in PR44780.

Differential Revision: https://reviews.llvm.org/D79219
2020-08-11 20:22:11 -07:00
Fangrui Song e973c1375e [ELF] Move the outSecOff addend from relocAlloc/relocNonAlloc/... to InputSectionBase::relocate
For an InputSection, the `buf` argument of `InputSectionBase::relocate` points
to the content of the containing OutputSection, instead of the content of the
InputSection itself, so `outSecOff` needs to be added in its callees.  This is
counter-intuitive and leads to many `- outSecOff` and `+ outSecOff`.

This patch makes `InputSection::writeTo` call `InputSectionBase::relocate` with
`outSecOff` added. relocAlloc/relocNonAlloc/relocateNonAllocForRelocatable can
thus be simplified now.

Updated test:

* non-abs-reloc.s: A minor offset bug is fixed for a diagnostic in `relocateNonAlloc`

Reviewed By: grimar

Differential Revision: https://reviews.llvm.org/D85618
2020-08-11 08:06:38 -07:00
Fangrui Song 73ca96ebc1 [ELF][test] Enhance x86-64-split-stack-prologue-adjust-success.s & non-abs-reloc.s
Catch problems when outSecOff is not zero and outSecOff is added twice or not added.
2020-08-11 08:06:36 -07:00
Pavel Labath c3817728e7 [lld] s/dyn_cast/isa
Fixes some unused variable warnings with gcc.
2020-08-11 15:22:44 +02:00
Georgii Rymar 026e0bf984 [LLD][ELF] - Update and fix gnu-ifunc* tests.
It turns that gnu-ifunc-plt-i386.s and gnu-ifunc-plt.s tests are broken.

Initially they were implemented in D27581 and tested that `IRELATIVE` relocations
are placed after other relocations in `.rel.plt`.

Later, we started to place `IRELATIVE` relocations to `.rela.dyn` (D65651).

Also, at some point `.plt` was renamed to `.iplt` (D71520).

Now, `gnu-ifunc*` tests mentioned do not test what they intended to test initially:
they should test that `IRELATIVE` relocations are placed after other ones in
`.rela.dyn`. Also, comments needs to be updated accordingly after changes performed.

This patch updates them.

Differential revision: https://reviews.llvm.org/D85642
2020-08-11 15:14:33 +03:00
Greg McGary 49fb1c2e90 [lld-macho] improve handling of -platform_version
This improves the handling of `-platform_version` by addressing the FIXME in the code to process the arguments.

Reviewed By: int3, #lld-macho

Differential Revision: https://reviews.llvm.org/D81413
2020-08-10 18:47:16 -07:00
Greg McGary a379f2c251 [lld-macho] Handle command-line option -sectcreate SEG SECT FILE
Handle command-line option `-sectcreate SEG SECT FILE`, which inputs a binary blob from `FILE` into `SEG,SECT`

Reviewed By: int3

Differential Revision: https://reviews.llvm.org/D85501
2020-08-10 18:47:13 -07:00
Alexandre Ganea a3036b3863 Re-Re-land: [CodeView] Add full repro to LF_BUILDINFO record
This patch adds the missing information to the LF_BUILDINFO record, which allows for rebuilding a .CPP without any external dependency but the .OBJ itself (other than the compiler).

Some external tools that we are using (Recode, Live++) are extracting the information to reproduce a build without any knowledge of the build system. The LF_BUILDINFO stores a full path to the compiler, the PWD (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 variables). 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
2020-08-10 13:36:30 -04:00
Wouter van Oortmerssen 582fd474dd [WebAssembly] wasm64: fix memory.init operand types
I had assumed they would all become in i64, but this is not necessary as long as data segments stay 32-bit, see:
https://github.com/WebAssembly/memory64/blob/master/proposals/memory64/Overview.md

Differential Revision: https://reviews.llvm.org/D85552
2020-08-10 10:15:20 -07:00
Alex Richardson e912fffd3a [ELF] Avoid creating a 2.1GB output file in arm-exidx-range.s
Currently both sections will be placed in the same PT_LOAD and therefore
lld generates a contiguous output file containing both sections.
By using AT(0xffff0000) the .vectors is placed a separate PT_LOAD and the
resulting file is now only a few kilobytes.

Reviewed By: psmith

Differential Revision: https://reviews.llvm.org/D85661
2020-08-10 18:08:07 +01:00
Sam Clegg b34ec5969f [lld][WebAssembly] Handle weakly referenced symbols when lazy (archive) version is see first
When a weak reference of a lazy symbol occurs we were not correctly
updating the lazy symbol.  We need to tag the existing lazy symbol
as weak and, in the case of a function symbol, give it a signature.

Without the signature we can't then create the dummy function which
is needed when an weakly undefined function is called.

We had tests for weakly referenced lazy symbols but we were only
tests in the case where the reference was seen before the lazy
symbol.

See: https://github.com/WebAssembly/wasi-libc/pull/214

Differential Revision: https://reviews.llvm.org/D85567
2020-08-10 08:16:55 -07:00
Fangrui Song 0334578edc [ELF] --wrap: don't leave the original symbol as SHN_UNDEF in .symtab or .dynsym 2020-08-08 18:18:20 -07:00
Petr Hosek a4d78d23c5 Revert "[CMake] Simplify CMake handling for zlib"
This reverts commit ccbc1485b5 which
is still failing on the Windows MLIR bots.
2020-08-08 17:08:23 -07:00
Petr Hosek ccbc1485b5 [CMake] Simplify CMake handling for zlib
Rather than handling zlib handling manually, use find_package from CMake
to find zlib properly. Use this to normalize the LLVM_ENABLE_ZLIB,
HAVE_ZLIB, HAVE_ZLIB_H. Furthermore, require zlib if LLVM_ENABLE_ZLIB is
set to YES, which requires the distributor to explicitly select whether
zlib is enabled or not. This simplifies the CMake handling and usage in
the rest of the tooling.

This is a reland of abb0075 with all followup changes and fixes that
should address issues that were reported in PR44780.

Differential Revision: https://reviews.llvm.org/D79219
2020-08-08 16:44:08 -07:00
Fangrui Song 99cd56906a [ELF] --wrap: set isUsedInRegularObj of __wrap_ if it is defined or shared
Fixes PR47017 (a regression when fixing PR46169): if __wrap_ is shared,
it is not exported.
2020-08-08 09:24:31 -07:00
Fangrui Song d30d461938 [ELF] Support .cfi_signal_frame
glibc/sysdeps/unix/sysv/linux/x86_64/sigaction.c libc.a(sigaction.o) has a CIE
with the augmentation string "zRS". Support 'S' to allow --icf={safe,all}.
2020-08-07 22:08:44 -07:00
Fangrui Song 164a02d0fa [ELF]: --icf: don't fold sections referencing sections with LCDA after D84610 2020-08-07 13:42:25 -07:00
Jez Ng 25367dfefb [lld-macho] Add .tbd support for frameworks
Required for e.g. linking iOS apps since they don't have a platform-native
SDK

Reviewed By: #lld-macho, compnerd, smeenai

Differential Revision: https://reviews.llvm.org/D85153
2020-08-07 11:04:54 -07:00
Jez Ng ca85e37338 [lld-macho] Support static linking of thread-locals
Note: What ELF refers to as "TLS", Mach-O seems to refer to as "TLV", i.e.
thread-local variables.

This diff implements support for TLV relocations that reference defined
symbols. On x86_64, TLV relocations are always used with movq opcodes, so for
defined TLVs, we don't need to create a synthetic section to store the
addresses of the symbols -- we can just convert the `movq` to a `leaq`.

One notable quirk of Mach-O's TLVs is that absolute-address relocations
inside TLV-defining sections behave differently -- their addresses are
no longer absolute, but relative to the start of the target section.
(AFAICT, RIP-relative relocations are not allowed in these sections.)

Reviewed By: #lld-macho, compnerd, smeenai

Differential Revision: https://reviews.llvm.org/D85080
2020-08-07 11:04:52 -07:00
Jez Ng 4e43f18048 [lld-macho] Ensure .tbss sections are also considered as ZeroFilled
This diff makes the behavior in {D80859} and {D81888} apply to
thread-local ZeroFill sections too. I realized this was necessary whie
trying to implement thread-local variables.

Reviewed By: #lld-macho, compnerd, MaskRay

Differential Revision: https://reviews.llvm.org/D85079
2020-08-07 11:04:41 -07:00
Victor Huang 6c64f05b90 [PowerPC] Add compatibility check for PPC PLT stubs
Compatibility checks for PPC64PltCallStub and PPC64PCRelPLTStub are
added in this patch to prevent the usage of incompatible thunk/stub.

Reviewed By: sfertile, nemanjai, stefanp

Differential Revision: https://reviews.llvm.org/D85459
2020-08-07 13:45:18 +00:00
Christian Kühnel f3cc4df51d Revert "[CMake] Simplify CMake handling for zlib"
This reverts commit 1adc494bce.
This patch broke the Windows compilation on buildbot and pre-merge testing:
http://lab.llvm.org:8011/builders/mlir-windows/builds/5945
https://buildkite.com/llvm-project/llvm-master-build/builds/780
2020-08-07 09:36:49 +02:00
Fangrui Song 004be4037e [ELF] Change tombstone values to (.debug_ranges/.debug_loc) 1 and (other .debug_*) 0
tl;dr See D81784 for the 'tombstone value' concept. This patch changes our behavior to be almost the same as GNU ld (except that we also use 1 for .debug_loc):

* .debug_ranges & .debug_loc: 1 (LLD<11: 0+addend; GNU ld uses 1 for .debug_ranges)
* .debug_*: 0 (LLD<11: 0+addend; GNU ld uses 0; future LLD: -1)

We make the tweaks because:

1) The new tombstone is novel and needs more time to be adopted by consumers before it's the default.
2) The old (gold) strategy had problems with zero-length functions - so rather than going back that, we're going to the GNU ld strategy which doesn't have that problem.
3) One slight tweak to (2) is to apply the .debug_ranges workaround to .debug_loc for the same reasons it applies to debug_ranges - to avoid terminating lists early.

-----

http://lists.llvm.org/pipermail/llvm-dev/2020-July/143482.html

The tombstone value -1 in .debug_line caused problems to lldb (fixed by D83957;
will be included in 11.0.0) and breakpad (fixed by
https://crrev.com/c/2321300). It may potentially affects other DWARF consumers.

For .debug_ranges & .debug_loc: 1, an argument preferring 1 (GNU ld for .debug_ranges) over -2 is that:
```
{-1, -2}    <<< base address selection entry
{0, length} <<< address range
```
may create a situation where low_pc is greater than high_pc. So we use
1, the GNU ld behavior for .debug_ranges

For other .debug_* sections, there haven't been many reports. One issue is that
bloaty (src/dwarf.cc) can incorrectly count address ranges in .debug_ranges . To
reduce similar disruption, this patch changes the tombstone values to be similar to GNU ld.

This does mean another behavior change to the default trunk behavior. Sorry
about it. The default trunk behavior will be similar to release/11.x while we work on a transition plan for LLD users.

Reviewed By: dblaikie, echristo

Differential Revision: https://reviews.llvm.org/D84825
2020-08-06 15:30:08 -07:00
Fangrui Song a6db64ef4a [ELF] Allow sections after a non-SHF_ALLOC section to be covered by PT_LOAD
GNU ld allows sections after a non-SHF_ALLOC section to be covered by PT_LOAD
(PR37607) and assigns addresses to non-SHF_ALLOC output sections (similar to
SHF_ALLOC NOBITS sections. The location counter is not advanced).

This patch tries to fix PR37607 (remove a special case in
`Writer<ELFT>::createPhdrs`). To make the created PT_LOAD meaningful, we cannot
reset dot to 0 for a middle non-SHF_ALLOC output section. This results in
removal of two special cases in LinkerScript::assignOffsets. Non-SHF_ALLOC
non-orphan sections can have non-zero addresses like in GNU ld.

The zero address rule for non-SHF_ALLOC sections is weakened to apply to orphan
only. This results in a special case in createSection and findOrphanPos, respectively.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D85100
2020-08-06 08:27:15 -07:00
Muhammad Omair Javaid d9e191cb17 Revert "[ELF] Allow sections after a non-SHF_ALLOC section to be covered by PT_LOAD"
This reverts commit 030ddc0a0b.

This breaks http://lab.llvm.org:8011/builders/lldb-arm-ubuntu
and http://lab.llvm.org:8011/builders/lldb-aarch64-ubuntu

Differential Revision: https://reviews.llvm.org/D85100
2020-08-06 16:30:05 +05:00
Fangrui Song 3af4039876 [ELF][test] Add another -triple=x86_64 to linkorder-mixed.s
Fixes an error on macOS:
error: mach-o section specifier uses an unknown section type
2020-08-05 17:00:37 -07:00
Shoaib Meenai 8b9e86fea6 [lld-macho] Fix errant search and replace. NFC 2020-08-05 16:59:53 -07:00
Fangrui Song 279e4cf782 [ELF] Fix type of ciesWithLSDA after D84610 2020-08-05 16:33:54 -07:00
Fangrui Song eb45b978b7 [ELF][test] Add REQUIES: x86 and -triple=x86_64 to linkorder-mixed.s 2020-08-05 16:28:44 -07:00
Fangrui Song b216c80cc2 [ELF] Allow SHF_LINK_ORDER sections to have sh_link=0
Part of https://bugs.llvm.org/show_bug.cgi?id=41734

The semantics of SHF_LINK_ORDER have been extended to represent metadata
sections associated with some other sections (usually text).

The associated text section may be discarded (e.g. LTO) and we want the
metadata section to have sh_link=0 (D72899, D76802).

Normally the metadata section is only referenced by the associated text
section. sh_link=0 means the associated text section is discarded, and
the metadata section will be garbage collected. If there is another
section (.gc_root) referencing the metadata section, the metadata
section will be retained. It's the .gc_root consumer's job to validate
the metadata sections.

  # This creates a SHF_LINK_ORDER .meta with sh_link=0
  .section .meta,"awo",@progbits,0
  1:
  .section .meta,"awo",@progbits,foo
  2:

  .section .gc_root,"a",@progbits
  .quad 1b
  .quad 2b

Reviewed By: pcc, jhenderson

Differential Revision: https://reviews.llvm.org/D72904
2020-08-05 16:17:42 -07:00
Petr Hosek 1adc494bce [CMake] Simplify CMake handling for zlib
Rather than handling zlib handling manually, use find_package from CMake
to find zlib properly. Use this to normalize the LLVM_ENABLE_ZLIB,
HAVE_ZLIB, HAVE_ZLIB_H. Furthermore, require zlib if LLVM_ENABLE_ZLIB is
set to YES, which requires the distributor to explicitly select whether
zlib is enabled or not. This simplifies the CMake handling and usage in
the rest of the tooling.

This is a reland of abb0075 with all followup changes and fixes that
should address issues that were reported in PR44780.

Differential Revision: https://reviews.llvm.org/D79219
2020-08-05 16:07:11 -07:00
Fangrui Song 030ddc0a0b [ELF] Allow sections after a non-SHF_ALLOC section to be covered by PT_LOAD
GNU ld allows sections after a non-SHF_ALLOC section to be covered by PT_LOAD
(PR37607) and assigns addresses to non-SHF_ALLOC output sections (similar to
SHF_ALLOC NOBITS sections. The location counter is not advanced).

This patch tries to fix PR37607 (remove a special case in
`Writer<ELFT>::createPhdrs`). To make the created PT_LOAD meaningful, we cannot
reset dot to 0 for a middle non-SHF_ALLOC output section. This results in
removal of two special cases in LinkerScript::assignOffsets. Non-SHF_ALLOC
non-orphan sections can have non-zero addresses like in GNU ld.

The zero address rule for non-SHF_ALLOC sections is weakened to apply to orphan
only. This results in a special case in createSection and findOrphanPos, respectively.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D85100
2020-08-05 09:30:23 -07:00
Fangrui Song 21b4f8060a [ELF] --icf: don't fold text sections with LSDA
Fix PR36272 and PR46835

A .eh_frame FDE references a text section and (optionally) a LSDA (in
.gcc_except_table).  Even if two text sections have identical content and
relocations (e.g. a() and b()), we cannot fold them if their LSDA are different.

```
void foo();
void a() {
  try { foo(); } catch (int) { }
}
void b() {
  try { foo(); } catch (float) { }
}
```

Scan .eh_frame pieces with LSDA and disallow referenced text sections to be
folded. If two .gcc_except_table have identical semantics (usually identical
content with PC-relative encoding), we will lose folding opportunity.
For ClickHouse (an exception-heavy application), this can reduce --icf=all efficiency
from 9% to 5%. There may be some percentage we can reclaim without affecting
correctness, if we analyze .eh_frame and .gcc_except_table sections.

gold 2.24 implemented a more complex fix (resolution to
https://sourceware.org/bugzilla/show_bug.cgi?id=21066) which combines the
checksum of .eh_frame CIE/FDE pieces.

Reviewed By: grimar

Differential Revision: https://reviews.llvm.org/D84610
2020-08-05 09:16:28 -07:00
Fangrui Song acb66b9111 [ELF] --oformat=binary: use LMA to compute file offsets
--oformat=binary is rare (used in a few places in FreeBSD, see `stand/i386/mbr/Makefile` `LDFLAGS_BIN`)
The result should be identical to a normal output transformed by `objcopy -O binary`.

The current implementation ignores addresses and lays out sections by
respecting output section alignments. It can fail when an output section
address is specified, e.g. `.rodata ALIGN(16) :` (PR33651).

Fix PR33651 by respecting LMA. The code is similar to
`tools/llvm-objcop/ELF/Object.cpp` BinaryWriter::finalize after D71035 and D79229.
Unforunately for an output section without PT_LOAD, we assume its LMA is equal
to its VMA. So the result is still incorrect when an output section LMA
(`AT(...)`) is specified

Also drop `alignTo(off, config->wordsize)`. GNU ld does not round up the file size.

Differential Revision: https://reviews.llvm.org/D85086
2020-08-05 09:10:01 -07:00
Saleem Abdulrasool 0ccda7c232 MachO: support `-syslibroot`
This adds support for the `-syslibroot` option.  This is required to
make the library search order actually function.  With this, it is now
possible to link a test Darwin x86_64 program with lld on Darwin.

Differential Revision: https://reviews.llvm.org/D82252
Reviewed By: Jez Ng
2020-08-05 08:41:24 -07:00
Hans Wennborg 3ab01550b6 Revert "[CMake] Simplify CMake handling for zlib"
This quietly disabled use of zlib on Windows even when building with
-DLLVM_ENABLE_ZLIB=FORCE_ON.

> Rather than handling zlib handling manually, use find_package from CMake
> to find zlib properly. Use this to normalize the LLVM_ENABLE_ZLIB,
> HAVE_ZLIB, HAVE_ZLIB_H. Furthermore, require zlib if LLVM_ENABLE_ZLIB is
> set to YES, which requires the distributor to explicitly select whether
> zlib is enabled or not. This simplifies the CMake handling and usage in
> the rest of the tooling.
>
> This is a reland of abb0075 with all followup changes and fixes that
> should address issues that were reported in PR44780.
>
> Differential Revision: https://reviews.llvm.org/D79219

This reverts commit 10b1b4a231 and follow-ups
64d99cc6ab and
f9fec0447e.
2020-08-05 12:31:44 +02:00
Fangrui Song bcea3a7a28 Add test utility 'split-file'
See https://lists.llvm.org/pipermail/llvm-dev/2020-July/143373.html
"[llvm-dev] Multiple documents in one test file" for some discussions.

This patch has explored several alternatives. The current semantics are similar to
what @dblaikie proposed.
`split-file filename output` splits the input file into multiple parts separated by
regex `^(.|//)--- filename` and write each part to the file `output/filename`
(`filename` can include path separators).

Use case A (organizing input of different formats (e.g. linker
script+assembly) in one file).

```
# RUN: split-file %s %t
# RUN: llvm-mc %t/asm -o %t.o
# RUN: ld.lld -T %t/lds %t.o -o %t
This is sometimes better than the %S/Inputs/ approach because the user
can see the auxiliary files immediately and don't have to open another file.

# asm
...
# lds
...
```

Use case B (for utilities which don't have built-in input splitting
feature):

```
// RUN: split-file %s %t
// RUN: llc < %t/1.ll | FileCheck %s --check-prefix=CASE1
// RUN: llc < %t/2.ll | FileCheck %s --check-prefix=CASE2
Combing tests prudently can improve readability.
For example, when testing parsing errors if the recovery mechanism isn't possible,
grouping the tests in one file can more readily see test coverage/strategy.

//--- 1.ll
...
//--- 2.ll
...
```

Since this is a new utility, there is no git history concerns for
UpperCase variable names. I use lowerCase variable names like mlir/lld.

Reviewed By: jhenderson, lattner

Differential Revision: https://reviews.llvm.org/D83834
2020-08-03 20:42:09 -07:00
Petr Hosek 81eeabbd97 [ELF] Add --dependency-file option
Clang and GCC have a feature (-MD flag) to create a dependency file
in a format that build systems such as Make or Ninja can read, which
specifies all the additional inputs such .h files.

This change introduces the same functionality to lld bringing it to
feature parity with ld and gold which gained this feature recently.
See https://sourceware.org/bugzilla/show_bug.cgi?id=22843 for more
details and discussion.

The implementation corresponds to -MD -MP compiler flag where the
generated dependency file also includes phony targets which works
around the errors where the dependency is removed. This matches the
format used by ld and gold.

Fixes PR42806

Differential Revision: https://reviews.llvm.org/D82437
2020-08-03 16:59:13 -07:00
Fangrui Song e281376e99 [ELF] --wrap: set isUsedInRegularObj of __wrap_ only if it is defined
Fixes PR46169
2020-08-01 18:19:14 -07:00
Sriraman Tallam 938adf42e6 Fix a test typo which caused a breakage. 2020-07-31 12:26:53 -07:00
Sriraman Tallam a77afc62d9 New test for basic block sections options.
This tests lld basic block sections options:
+ --lto-basic-block-sections=
+ --lto-unique-basic-block-section-names

Differential Revision: https://reviews.llvm.org/D84462
2020-07-31 12:02:52 -07:00
Sriraman Tallam ca6b6d40ff Rename basic block sections options to be consistent.
D68049 created options for basic block sections: -fbasic-block-sections=,
-funique-basic-block-section-names. Rename options in llc and lld (--lto-)
to be consistent. Specifically,

+ Rename basicblock-sections to basic-block-sections
+ Rename unique-bb-section-names to unique-basic-block-section-names

Differential Revision: https://reviews.llvm.org/D84462
2020-07-31 11:50:55 -07:00
Petr Hosek 0bd918c828 Revert "[ELF] Add --dependency-file option"
This reverts commit b4c7657ba6 which
seems to be breaking certain bots with assertion error.
2020-07-31 01:12:59 -07:00
Wolfgang Pieb 9f02258942 Make a test case more flexible on Windows wrt the number of backslashes. 2020-07-30 20:38:12 -07:00
Zequan Wu 763671f387 [COFF] Port CallGraphSort to COFF from ELF 2020-07-30 15:21:44 -07:00
Jez Ng c89e46e767 [lld-macho] Add comment for literal argument 2020-07-30 14:38:58 -07:00
Jez Ng 98210796e1 [lld-macho] Make __LINKEDIT sections contiguous
codesign (or more specifically libstuff) checks that each section in
__LINKEDIT ends where the next one starts -- no gaps are permitted. This
diff achieves it by aligning every section's start and end points to
WordSize.

Remarks: ld64 appears to satisfy the constraint by adding padding bytes
when generating the __LINKEDIT data, e.g. by emitting BIND_OPCODE_DONE
(which is a 0x0 byte) repeatedly. I think the approach this diff takes
is a bit more elegant, but I'm not sure if it's too restrictive. In
particular, it assumes padding always uses the zero byte. But we can
revisit this later.

Reviewed By: #lld-macho, compnerd

Differential Revision: https://reviews.llvm.org/D84718
2020-07-30 14:30:07 -07:00
Jez Ng 22e6648a18 [lld-macho] Implement -headerpad
Tools like `install_name_tool` and `codesign` may modify the Mach-O
header and increase its size. The linker has to provide padding to make this
possible. This diff does that, plus sets its default value to 32 bytes (which
is what ld64 does).

Unlike ld64, however, we lay out our sections *exactly* `-headerpad` bytes from
the header, whereas ld64 just treats the padding requirement as a lower bound.
ld64 actually starts laying out the non-header sections in the __TEXT segment
from the end of the (page-aligned) segment rather than the front, so its
binaries typically have more than `-headerpad` bytes of actual padding.
We should consider implementing the same alignment behavior.

Reviewed By: #lld-macho, compnerd

Differential Revision: https://reviews.llvm.org/D84714
2020-07-30 14:29:31 -07:00
Jez Ng 3587de2281 [lld-macho] Support __dso_handle for C++
The C++ ABI requires dylibs to pass a pointer to __cxa_atexit which does
e.g. cleanup of static global variables. The C++ spec says that the pointer
can point to any address in one of the dylib's segments, but in practice
ld64 seems to set it to point to the header, so that's what's implemented
here.

Reviewed By: #lld-macho, smeenai

Differential Revision: https://reviews.llvm.org/D83603
2020-07-30 14:28:41 -07:00
Peiyuan Song da324f9904 [LLD] [Mingw] Don't export symbols from profile generate
Differential Revision: https://reviews.llvm.org/D84756
2020-07-30 23:33:20 +03:00
Petr Hosek b4c7657ba6 [ELF] Add --dependency-file option
Clang and GCC have a feature (-MD flag) to create a dependency file
in a format that build systems such as Make or Ninja can read, which
specifies all the additional inputs such .h files.

This change introduces the same functionality to lld bringing it to
feature parity with ld and gold which gained this feature recently.
See https://sourceware.org/bugzilla/show_bug.cgi?id=22843 for more
details and discussion.

The implementation corresponds to -MD -MP compiler flag where the
generated dependency file also includes phony targets which works
around the errors where the dependency is removed. This matches the
format used by ld and gold.

Fixes PR42806

Differential Revision: https://reviews.llvm.org/D82437
2020-07-30 12:31:20 -07:00
Fangrui Song ed7bde0e4b [ELF][test] Fix ppc64-reloc-pcrel34-overflow.s 2020-07-29 13:01:31 -07:00
Victor Huang 8dbea4785c [PowerPC] Support for R_PPC64_REL24_NOTOC calls where the caller has no TOC and the callee is not DSO local
This patch supports the situation where caller does not have a valid TOC and
calls using the R_PPC64_REL24_NOTOC relocation and the callee is not DSO local.
In this case the call cannot be made directly since the callee may or may not
require a valid TOC pointer. As a result this situation require a PC-relative
plt stub to set up r12.

Reviewed By: sfertile, MaskRay, stefanp

Differential Revision: https://reviews.llvm.org/D83669
2020-07-29 19:49:28 +00:00
Andrew Ng 8725a49409 [ELF][test] Add test coverage of `__real_` to wrap-plt.s
Differential Revision: https://reviews.llvm.org/D84749
2020-07-29 14:10:38 +01:00
Fangrui Song dd405f1a53 Revert D83834 "Add test utility 'extract'"
This reverts commit d054c7ee2e.

There are discussions about the utility name, its functionality and user interface.
Revert before we reach consensus.
2020-07-28 13:26:33 -07:00
Hafiz Abid Qadeer 1f166edeb4 [lld][linkerscript] Fix handling of DEFINED.
Current implementation did not check that symbols is actually defined. Only checked for presence.  GNU ld documentation says,

"Return 1 if symbol is in the linker global symbol table and is defined before the statement using DEFINED in the script, otherwise return 0."

https://sourceware.org/binutils/docs/ld/Builtin-Functions.html#Builtin-Functions

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D83758
2020-07-28 21:18:01 +01:00
Martin Storsjö 745eb02496 [LLD] [MinGW] Implement the --no-seh flag
Previously this flag was just ignored. If set, set the
IMAGE_DLL_CHARACTERISTICS_NO_SEH bit, regardless of the normal safeSEH
machinery.

In mingw configurations, the safeSEH bit might not be set in e.g. object
files built from handwritten assembly, making it impossible to use the
normal safeseh flag. As mingw setups don't generally use SEH on 32 bit
x86 at all, it should be fine to set that flag bit though - hook up
the existing GNU ld flag for controlling that.

Differential Revision: https://reviews.llvm.org/D84701
2020-07-28 21:08:37 +03:00
Jez Ng a5b89c2853 [lld-macho] Fix no-filelist test on Windows 2020-07-28 11:04:43 -07:00
Jez Ng d32e32500f [lld-macho] Fix segment filesize calculation
The previous approach of adding up the file sizes of the
component sections ignored the fact that the sections did not have to be
contiguous in the file. As such, it was underestimating the true size.

I discovered this issue because `codesign` checks whether `__LINKEDIT`
extends to the end of the file. Since we were underestimating segment
sizes, this check failed.

Reviewed By: #lld-macho, compnerd

Differential Revision: https://reviews.llvm.org/D84574
2020-07-28 10:02:19 -07:00
Jez Ng 4853a86022 [lld-macho] Support -filelist
XCode passes files in using this flag

Reviewed By: #lld-macho, compnerd

Differential Revision: https://reviews.llvm.org/D84486
2020-07-28 10:02:19 -07:00
Christy Lee bd4757cc4e [ELF] --reproduce should include lto sample profile
Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D84569
2020-07-28 09:41:41 -07:00
Petr Hosek 64d99cc6ab [CMake] Move find_package(ZLIB) to LLVMConfig
This way, downstream projects don't have to invoke find_package(ZLIB)
reducing the amount of boilerplate.

Differential Revision: https://reviews.llvm.org/D84691
2020-07-27 17:13:55 -07:00
Logan Smith a52aea0ba6 Use INTERFACE_COMPILE_OPTIONS to disable -Wsuggest-override for any target that links to gtest
This cleans up several CMakeLists.txt's where -Wno-suggest-override was manually specified. These test targets now inherit this flag from the gtest target.

Some unittests CMakeLists.txt's, in particular Flang and LLDB, are not touched by this patch. Flang manually adds the gtest sources itself in some configurations, rather than linking to LLVM's gtest target, so this fix would be insufficient to cover those cases. Similarly, LLDB has subdirectories that manually add the gtest headers to their include path without linking to the gtest target, so those subdirectories still need -Wno-suggest-override to be manually specified to compile without warnings.

Differential Revision: https://reviews.llvm.org/D84554
2020-07-27 08:37:01 -07:00
Martin Storsjö 343ffa70fc [LLD] [COFF] Fix mingw comdat associativity for leader symbols with a different name
For a weak symbol func in a comdat, the actual leader symbol ends up
named like .weak.func.default*. Likewise, for stdcall on i386, the symbol
may be named _func@4, while the section suffix only is "func", which the
previous implementation didn't handle.

This fixes unwinding through weak functions when using
-ffunction-sections in mingw environments.

Differential Revision: https://reviews.llvm.org/D84607
2020-07-27 17:32:08 +03:00
Isaac Richter fa1145a8d2 [lld][ELF] Add LOG2CEIL builtin ldscript function
This patch adds support for the LOG2CEIL builtin function in linker scripts: https://sourceware.org/binutils/docs/ld/Builtin-Functions.html#index-LOG2CEIL_0028exp_0029

As documented for LD, and to keep compatibility, LOG2CEIL(0) returns 0 (not -inf).

The test vectors are somewhat arbitrary. We check minimum values (0-4); middle values (2^32, and 2^32+1); and the maximum value (2^64-1).

The checks for LOG2CEIL explicitly use full 64-bit values (16 hex digits). This is needed to properly verify that -inf and other interesting results aren't returned. (For some reason, all other tests in operators.test use only 14 digits.)

Differential revision: https://reviews.llvm.org/D84054
2020-07-27 12:16:43 +03:00
Martin Storsjö 8dc8203932 [LLD] [COFF] Fix test to properly test all aspects of c3b1d730d6. NFC.
Previously, the test could pass with one part of c3b1d730d6 removed.
2020-07-26 23:10:20 +03:00
Jez Ng 9282d04e04 [lld-macho] Support lookup of dylibs in frameworks
Needed for testing Objective-C programs (since e.g. Core
Foundation is a framework)

Reviewed By: #lld-macho, compnerd

Differential Revision: https://reviews.llvm.org/D83925
2020-07-26 12:46:46 -07:00
Jez Ng 06a0dd2467 [lld-macho] Ignore -dependency_info and its argument
XCode passes in this flag, which we do not yet implement. Skip
over the argument for now so we can at least successfully parse the
linker invocation.

Reviewed By: #lld-macho, compnerd

Differential Revision: https://reviews.llvm.org/D84485
2020-07-24 15:55:27 -07:00
Jez Ng 31d5885842 [lld-macho] Partial support for weak definitions
This diff adds support for weak definitions, though it doesn't handle weak
symbols in dylibs quite correctly -- we need to emit binding opcodes for them
in the weak binding section rather than the lazy binding section.

What *is* covered in this diff:

1. Reading the weak flag from symbol table / export trie, and writing it to the
   export trie
2. Refining the symbol table's rules for choosing one symbol definition over
   another. Wrote a few dozen test cases to make sure we were matching ld64's
   behavior.

We can now link basic C++ programs.

Reviewed By: #lld-macho, compnerd

Differential Revision: https://reviews.llvm.org/D83532
2020-07-24 15:55:25 -07:00
Georgii Rymar ae4279bd3e [LLD][ELF] - Linkerscript: report location for the "unclosed comment in a linker script" error.
Currently we print "error: unclosed comment in a linker script", which doesn't
provide information about the real error location.

Fixes https://bugs.llvm.org/show_bug.cgi?id=46793.

Differential revision: https://reviews.llvm.org/D84300
2020-07-24 11:38:26 +03:00
Petr Hosek 10b1b4a231 [CMake] Simplify CMake handling for zlib
Rather than handling zlib handling manually, use find_package from CMake
to find zlib properly. Use this to normalize the LLVM_ENABLE_ZLIB,
HAVE_ZLIB, HAVE_ZLIB_H. Furthermore, require zlib if LLVM_ENABLE_ZLIB is
set to YES, which requires the distributor to explicitly select whether
zlib is enabled or not. This simplifies the CMake handling and usage in
the rest of the tooling.

This is a reland of abb0075 with all followup changes and fixes that
should address issues that were reported in PR44780.

Differential Revision: https://reviews.llvm.org/D79219
2020-07-23 23:05:36 -07:00
Fangrui Song d054c7ee2e Add test utility 'extract'
See https://lists.llvm.org/pipermail/llvm-dev/2020-July/143373.html
"[llvm-dev] Multiple documents in one test file" for some discussions.

`extract part filename` splits the input file into multiple parts separated by
regex `^(.|//)--- ` and extract the specified part to stdout or the
output file (if specified).

Use case A (organizing input of different formats (e.g. linker
script+assembly) in one file).

```
// RUN: extract lds %s -o %t.lds
// RUN: extract asm %s -o %t.s
// RUN: llvm-mc %t.s -o %t.o
// RUN: ld.lld -T %t.lds %t.o -o %t
This is sometimes better than the %S/Inputs/ approach because the user
can see the auxiliary files immediately and don't have to open another file.
```

Use case B (for utilities which don't have built-in input splitting
feature):

```
// RUN: extract case1 %s | llc | FileCheck %s --check-prefix=CASE1
// RUN: extract case2 %s | llc | FileCheck %s --check-prefix=CASE2
Combing tests prudently can improve readability.
This is sometimes better than having multiple test files.
```

Since this is a new utility, there is no git history concerns for
UpperCase variable names. I use lowerCase variable names like mlir/lld.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D83834
2020-07-23 19:15:35 -07:00
Petr Hosek 38c71b7c85 Revert "[CMake] Simplify CMake handling for zlib"
This reverts commit 1d09ecf361 since
it breaks sanitizer bots.
2020-07-23 15:12:42 -07:00
Petr Hosek 1d09ecf361 [CMake] Simplify CMake handling for zlib
Rather than handling zlib handling manually, use find_package from CMake
to find zlib properly. Use this to normalize the LLVM_ENABLE_ZLIB,
HAVE_ZLIB, HAVE_ZLIB_H. Furthermore, require zlib if LLVM_ENABLE_ZLIB is
set to YES, which requires the distributor to explicitly select whether
zlib is enabled or not. This simplifies the CMake handling and usage in
the rest of the tooling.

This is a reland of abb0075 with all followup changes and fixes that
should address issues that were reported in PR44780.

Differential Revision: https://reviews.llvm.org/D79219
2020-07-23 14:47:25 -07:00
Fangrui Song 4e80c768c2 [ELF] Support -r --gc-sections
-r --gc-sections is usually not useful because it just makes intermediate output
smaller. https://bugs.llvm.org/show_bug.cgi?id=46700#c7 mentions a use case:
validating the absence of undefined symbols ealier than in the final link.

After D84129 (SHT_GROUP support in -r links), we can support -r
--gc-sections without extra code. So let's allow it.

Reviewed By: grimar, jhenderson

Differential Revision: https://reviews.llvm.org/D84131
2020-07-23 08:16:01 -07:00
Logan Smith 77e0e9e17d Reapply "Try enabling -Wsuggest-override again, using add_compile_options instead of add_compile_definitions for disabling it in unittests/ directories."
add_compile_options is more sensitive to its location in the file than add_definitions--it only takes effect for sources that are added after it. This updated patch ensures that the add_compile_options is done before adding any source files that depend on it.

Using add_definitions caused the flag to be passed to rc.exe on Windows and thus broke Windows builds.
2020-07-22 17:50:19 -07:00
Logan Smith 97a0f80c46 Revert "Try enabling -Wsuggest-override again, using add_compile_options instead of add_compile_definitions for disabling it in unittests/ directories."
This reverts commit 388c9fb1af.
2020-07-22 15:07:01 -07:00
Logan Smith 388c9fb1af Try enabling -Wsuggest-override again, using add_compile_options instead of add_compile_definitions for disabling it in unittests/ directories.
Using add_compile_definitions caused the flag to be passed to rc.exe on Windows and thus broke Windows builds.
2020-07-22 14:19:34 -07:00
Louis Dionne afa1afd410 [CMake] Bump CMake minimum version to 3.13.4
This upgrade should be friction-less because we've already been ensuring
that CMake >= 3.13.4 is used.

This is part of the effort discussed on llvm-dev here:

  http://lists.llvm.org/pipermail/llvm-dev/2020-April/140578.html

Differential Revision: https://reviews.llvm.org/D78648
2020-07-22 14:25:07 -04:00
Hans Wennborg 3eec657825 Revert "Enable -Wsuggest-override in the LLVM build" and the follow-ups.
After lots of follow-up fixes, there are still problems, such as
-Wno-suggest-override getting passed to the Windows Resource Compiler
because it was added with add_definitions in the CMake file.

Rather than piling on another fix, let's revert so this can be re-landed
when there's a proper fix.

This reverts commit 21c0b4c1e8.
This reverts commit 81d68ad27b.
This reverts commit a361aa5249.
This reverts commit fa42b7cf29.
This reverts commit 955f87f947.
This reverts commit 8b16e45f66.
This reverts commit 308a127a38.
This reverts commit 274b6b0c7a.
This reverts commit 1c7037a2a5.
2020-07-22 20:23:58 +02:00
Logan Smith 81d68ad27b [lld] Disable -Wsuggest-override for unittests 2020-07-21 17:40:59 -07:00
Fangrui Song 86ab98b001 [ELF] -r: rewrite SHT_GROUP content if some members are combined or discarded
* If two group members are combined, we should leave just one index in the SHT_GROUP content.
* If a group member is discarded (/DISCARD/ or upcoming -r --gc-sections combination),
  we should drop its index in the SHT_GROUP content. LLD currently crashes (`getOutputSection()` is null).

Reviewed By: psmith

Differential Revision: https://reviews.llvm.org/D84129
2020-07-21 08:49:45 -07:00
Victor Huang 91cce1a2bc [PowerPC] Implement R_PPC64_REL24_NOTOC local calls, callee requires a TOC
The PC Relative code now allows for calls that are marked with the relocation
R_PPC64_REL24_NOTOC. This indicates that the caller does not have a valid TOC
pointer in R2 and does not require R2 to be restored after the call.

This patch is added to support local calls to callees that require a TOC

Reviewed By: sfertile, MaskRay, nemanjai, stefanp

Differential Revision: https://reviews.llvm.org/D83504
2020-07-20 17:46:49 +00:00
Sylvain Audi 3a108ab256 [LLD][COFF] Skip computation of the undefined symbols references that are not shown
The "undefined symbol" error message from lld-link displays up to 3 references to that symbol, and the number of extra references not shown.

This patch removes the computation of the strings for those extra references.

It fixes a freeze of lld-link we accidentally encountered when activating asan on a large project, without linking with the asan library.
In that case, __asan_report_load8 was referenced more than 2 million times, causing the computation of that many display strings, of which only 3 were used.

Differential Revision: https://reviews.llvm.org/D83510
2020-07-20 13:45:16 -04:00
Hans Wennborg 8a197e0b16 Require shell for lld/test/ELF/arm-exidx-range.s
The test fails in 32-bit Windows builds for unclear reasons:

ld.lld: error: failed to open
C:\src\llvm_package_1100-rc1\build32_stage0\tools\lld\test\ELF\Output\arm-exidx-range.s.tmp:
The parameter is incorrect.
2020-07-20 17:49:10 +02:00
Georgii Rymar ef377d3f2d [LLD][ELF] - Update the lld/test/ELF/mips-merge-abiflags.s after llvm-readelf change.
The warning message was updated
(https://reviews.llvm.org/rG256aea816da45bd3bc52317cbc89e704095a8991)
2020-07-20 12:17:49 +03:00
Fangrui Song 7099a4b56b [ELF][test] Update test after DW_EH_PE_sdata4/DW_EH_PE_sdata8 change 2020-07-18 09:07:50 -07:00
Michele Scandale 53880b8cb9 [CMake] Make `intrinsics_gen` dependency unconditional.
The `intrinsics_gen` target exists in the CMake exports since r309389
(see LLVMConfig.cmake.in), hence projects can depend on `intrinsics_gen`
even it they are built separately from LLVM.

Reviewed By: MaskRay, JDevlieghere

Differential Revision: https://reviews.llvm.org/D83454
2020-07-17 16:43:17 -07:00
Benjamin Kramer 9a0689e072 Make helpers static. NFC. 2020-07-17 13:49:11 +02:00
Wouter van Oortmerssen cc1b9b680f [WebAssembly] 64-bit (function) pointer fixes.
Accounting for the fact that Wasm function indices are 32-bit, but in wasm64 we want uniform 64-bit pointers.
Includes reloc types for 64-bit table indices.

Differential Revision: https://reviews.llvm.org/D83729
2020-07-16 14:10:22 -07:00
Wouter van Oortmerssen 29f8c9f6c2 [WebAssembly] Triple::wasm64 related cleanup
Differential Revision: https://reviews.llvm.org/D83713
2020-07-16 12:01:10 -07:00
Hans Wennborg 7ab7b979d2 Bump the trunk major version to 12
and clear the release notes.
2020-07-15 12:05:05 +02:00
Georgii Rymar 2e10b7a39b [LLD][ELF] - Update test after yaml2obj change. NFC.
Names of YAML keys changed in rG7a587ca93200c49e47fe205ce037895c81c5a542
2020-07-15 13:00:48 +03:00
Martin Storsjö 92f7bd3a39 [LLD] [MinGW] Implement the --file-alignment and --section-alignment options
Differential Revision: https://reviews.llvm.org/D83720
2020-07-15 08:34:08 +03:00
Petr Hosek bcd27d9d73 Revert "[CMake] Simplify CMake handling for zlib"
This reverts commit 8c1a79dc12 because
it fails when zlib isn't installed.
2020-07-14 19:56:10 -07:00
Petr Hosek 8c1a79dc12 [CMake] Simplify CMake handling for zlib
Rather than handling zlib handling manually, use find_package from CMake
to find zlib properly. Use this to normalize the LLVM_ENABLE_ZLIB,
HAVE_ZLIB, HAVE_ZLIB_H. Furthermore, require zlib if LLVM_ENABLE_ZLIB is
set to YES, which requires the distributor to explicitly select whether
zlib is enabled or not. This simplifies the CMake handling and usage in
the rest of the tooling.

This is a reland of abb0075 with all followup changes and fixes that
should address issues that were reported in PR44780.

Differential Revision: https://reviews.llvm.org/D79219
2020-07-14 19:30:08 -07:00
Igor Kudrin c4fc26b4c0 [ELF] Do not leave undefined symbols (specified by -init and -fini) if they are defined in non-fetched archive members
After D69985, symbols for "-init" and "-fini" were unconditionally
marked as used even if they were just lazy symbols seen when scanning
archives. That resulted in exposing them in the symbol table of an
output file, as Undefined, which added unwanted dependencies. The patch
fixes the issue by checking the kind of the symbols before the marking.

Differential Revision: https://reviews.llvm.org/D83549
2020-07-14 16:35:17 +07:00
Georgii Rymar fbb6c9df28 [LLD][ELF] - Fix the test after llvm-readelf output change.
An issue for llvm-readelf was fixed in
https://reviews.llvm.org/rG84a170178c4431b7536c83ff0e5ce80774d08df6

Now it produce no output for this test.
2020-07-13 15:18:30 +03:00
Hans Wennborg e73d0b5719 [COFF] Error on unexpected .pdata size
Previously, lld would crash if the .pdata size was not an even multiple
of the expected .pdata entry size. This makes it error gracefully instead.

(We hit this in Chromium due to an assembler problem: https://crbug.com/1101577)

Differential revision: https://reviews.llvm.org/D83479
2020-07-13 13:38:39 +02:00
Ben Dunbobbin 6bda276f93 [LLD][ELF][Windows] small improvement to D82567
Bail early if there is no existing output file to be overwritten.

Differential Revision: https://reviews.llvm.org/D83272
2020-07-13 12:02:20 +01:00
Georgii Rymar af16a45683 [LLD][ELF] - Allow relocation sections to appear before their target sections.
It allows handling cases when we have SHT_REL[A] sections before target
sections in objects.

This fixes https://bugs.llvm.org/show_bug.cgi?id=46632

which says: "Normally it is not what compilers would emit. We have to support it,
because some custom tools might want to use this feature, which is not restricted by ELF gABI"

Differential revision: https://reviews.llvm.org/D83469
2020-07-13 13:59:54 +03:00
Ayke van Laethem 69e60c9dc7
[LLD][ELF][AVR] Implement the missing relocation types
Implements the missing relocation types for AVR target.
The results have been cross-checked with binutils.

Original patch by LemonBoy. Some changes by me.

Differential Revision: https://reviews.llvm.org/D78741
2020-07-12 18:18:54 +02:00
Eric Christopher 256e4d46a6 Fix signed vs unsigned comparison warnings a different way. 2020-07-10 22:52:50 -07:00
Alexandre Ganea b71499ac9e Revert "Re-land [CodeView] Add full repro to LF_BUILDINFO record"
This reverts commit add59ecb34 and 41d2813a5f.
2020-07-10 19:46:16 -04:00
Alexandre Ganea add59ecb34 Re-land [CodeView] Add full repro to LF_BUILDINFO record
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
2020-07-10 13:59:28 -04:00
Victor Huang 118366dcb6 [PowerPC] Implement R_PPC64_REL24_NOTOC calls, callee also has no TOC
The PC Relative code allows for calls that are marked with the relocation
R_PPC64_REL24_NOTOC. This indicates that the caller does not have a valid TOC
pointer in R2 and does not require R2 to be restored after the call.

This patch is added to support local calls to callees tha also do not have a TOC.

Reviewed By: sfertile, MaskRay, stefanp

Differential Revision: https://reviews.llvm.org/D82816
2020-07-10 07:23:32 -05:00
Eric Christopher 98eec7700c Temporarily Revert "Fix [-Werror,-Wsign-compare] warnings arising from subsection symbols patch."
as it's causing build errors with another clang so I'll need to approach
this differently.

This reverts commit c282708316.
2020-07-09 13:46:59 -07:00
Eric Christopher c282708316 Fix [-Werror,-Wsign-compare] warnings arising from subsection symbols patch. 2020-07-09 11:14:00 -07:00
Stefan Pintilie 6f7727db47 [PowerPC] Fix test case from beb52b12cb
Forgot to add the REQUIRES ppc line to the test.
2020-07-09 12:39:24 -05:00
Stefan Pintilie beb52b12cb [PowerPC] Support PCRelative Callees for R_PPC64_REL24 Relocation
The R_PPC64_REL24 is used in function calls when the caller requires a
valid TOC pointer. If the callee shares the same TOC or does not clobber
the TOC pointer then a direct call can be made. If the callee does not
share the TOC a thunk must be added to save the TOC pointer for the caller.

Up until PC Relative was introduced all local calls on medium and large code
models were assumed to share a TOC. This is no longer the case because
if the caller requires a TOC and the callee is PC Relative then the callee
can clobber the TOC even if it is in the same DSO.

This patch is to add support for a TOC caller calling a PC Relative callee that
clobbers the TOC.

Reviewed By: sfertile, MaskRay

Differential Revision: https://reviews.llvm.org/D82950
2020-07-09 09:50:19 -05:00
Igor Kudrin ca4d8da0c3 [DebugInfo] Add more checks to parsing .debug_pub* sections.
The patch adds checking for various potential issues in parsing name
lookup tables and reporting them as recoverable errors, similarly as we
do for other tables.

Differential Revision: https://reviews.llvm.org/D83050
2020-07-09 19:15:31 +07:00
Igor Kudrin 68f5a8b204 [DebugInfo] Do not hang when parsing a malformed .debug_pub* section.
The parsing method did not check reading errors and might easily fall
into an infinite loop on an invalid input because of that.

Differential Revision: https://reviews.llvm.org/D83049
2020-07-09 19:15:11 +07:00
Fangrui Song f86d96a964 [ELF] Enforce double-dash form for --warn-backrefs-exclude
This is an LLD-specific option. We have enforced double-dash forms for
other options (reduce collision with short options) but missed this one.
2020-07-08 11:45:01 -07:00
Fangrui Song 169ec2d6b0 [ELF] Rename canRelax to toExecRelax. NFC
In the absence of TLS relaxation (rewrite of code sequences),
there is still an applicable optimization:

[gd]: General Dynamic: resolve DTPMOD to 1 and/or resolve DTPOFF statically

All the other relaxations are only performed when transiting to
executable (`!config->shared`).
Since [gd] is handled differently, we can fold `!config->shared` into canRelax
and simplify its use sites. Rename the variable to reflect to new semantics.

Reviewed By: grimar, psmith

Differential Revision: https://reviews.llvm.org/D83243
2020-07-08 10:27:31 -07:00
Fangrui Song 4ce56b8122 [ELF] Add -z dead-reloc-in-nonalloc=<section_glob>=<value>
... to customize the tombstone value we use for an absolute relocation
referencing a discarded symbol. This can be used as a workaround when
some debug processing tool has trouble with current -1 tombstone value
(https://bugs.chromium.org/p/chromium/issues/detail?id=1102223#c11 )

For example, to get the current built-in rules (not considering the .debug_line special case for ICF):

```
-z dead-reloc-in-nonalloc='.debug_*=0xffffffffffffffff'
-z dead-reloc-in-nonalloc=.debug_loc=0xfffffffffffffffe
-z dead-reloc-in-nonalloc=.debug_ranges=0xfffffffffffffffe
```

To get GNU ld (as of binutils 2.35)'s behavior:

```
-z dead-reloc-in-nonalloc='*=0'
-z dead-reloc-in-nonalloc=.debug_ranges=1
```

This option has other use cases. For example, if we want to check
whether a non-SHF_ALLOC section has dead relocations.
With this patch, we can run a regular LLD and run another with a special
-z dead-reloc-in-nonalloc=, then compare their output.

Reviewed By: thakis

Differential Revision: https://reviews.llvm.org/D83264
2020-07-08 10:15:16 -07:00
Fangrui Song 09b81a72ac [ELF] Ignore --no-relax for RISC-V
In GNU ld, --no-relax can disable x86-64 GOTPCRELX relaxation.
It is not useful, so we don't implement it.

For RISC-V, --no-relax disables linker relaxations which have larger
impact.
Linux kernel specifies --no-relax when CONFIG_DYNAMIC_FTRACE is specified
(since http://git.kernel.org/linus/a1d2a6b4cee858a2f27eebce731fbf1dfd72cb4e ).
LLD has not implemented the relaxations, so this option is a no-op.

Reviewed By: grimar

Differential Revision: https://reviews.llvm.org/D81359
2020-07-07 09:48:13 -07:00
Wouter van Oortmerssen 4d135b0446 [WebAssembly] 64-bit memory limits 2020-07-06 12:40:45 -07:00
William S. Moses dc6b3f03a8 [ELF] Drop an unneeded reference to `symtab` from SymbolTable::addSymbol
The Symbol Table in LLD references the global object to add a symbol rather than adding it to itself.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D83184
2020-07-06 12:05:54 -07:00
Fangrui Song c1a5f73a4a [ELF][ARM] Represent R_ARM_LDO32 as R_DTPREL instead of R_ABS
Follow-up to D82899. Note, we need to disable R_DTPREL relaxation
because ARM psABI does not define TLS relaxation.

Reviewed By: grimar, psmith

Differential Revision: https://reviews.llvm.org/D83138
2020-07-06 09:47:53 -07:00
Fangrui Song 6fa1343bb3 [ELF] Resolve R_DTPREL in .debug_* referencing discarded symbols to -1
The location of a TLS variable is encoded as a DW_OP_const4u/DW_OP_const8u
followed by a DW_OP_push_tls_address (or DW_OP_GNU_push_tls_address https://sourceware.org/bugzilla/show_bug.cgi?id=11616 ).

This change follows up to D81784 and makes relocations types generalized as
R_DTPREL (e.g. R_X86_64_DTPOFF{32,64}, R_PPC64_DTPREL64) use -1 as the
tombstone value as well. This works for both TLS Variant I and Variant II
architectures.

* arm: .long tls(tlsldo)   # not working currently (R_ARM_TLS_LDO32 is R_ABS)
* mips64: .dtpreldword tls+32768
* ppc64: .quad tls@DTPREL+0x8000
* riscv: neither GCC nor clang has implemented DW_AT_location. It is likely .long/.quad tls@dtprel+0x800
* x86-32: .long tls@DTPOFF
* x86-64: .long tls@DTPOFF; .quad tls@DTPOFF

tls has a non-negative st_value, so such relocations (st_value+addend)
never resolve to -1 in a normal (not discarded) case.

```
// clang -fuse-ld=lld -g -ffunction-sections a.c -Wl,--gc-sections
// foo and tls will be discarded by --gc-sections.
// DW_AT_location [DW_FORM_exprloc] (DW_OP_const8u 0xffffffffffffffff, DW_OP_GNU_push_tls_address)
thread_local int tls;
int foo() { return ++tls; }
int main() {}
```

Also, drop logic added in D26201 intended to address PR30793. It added a test
(gc-debuginfo-tls.s) using a non-SHF_ALLOC section and a local symbol, which
does not reflect the intended scenario: a relocation in a SHF_ALLOC section
referencing a discarded non-local symbol. For such a non .debug_* section, just
emit an error.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D82899
2020-07-03 09:50:30 -07:00
Ben Dunbobbin f42f599d37 [LLD][ELF][Windows] Allow LLD to overwrite existing output files that are in use
On Windows co-operative programs can be expected to open LLD's
output in FILE_SHARE_DELETE mode. This allows us to delete the
file (by moving it to a temporary filename and then deleting
it) so that we can link another output file that overwrites
the existing file, even if the current file is in use.

A similar strategy is documented here:
https://boostgsoc13.github.io/boost.afio/doc/html/afio/FAQ/deleting_open_files.html

Differential Revision: https://reviews.llvm.org/D82567
2020-07-03 13:08:56 +01:00
Jez Ng 53eb7fda51 [lld-macho] Support binding dysyms to any section
Previously, we only supported binding dysyms to the GOT. This
diff adds support for binding them to any arbitrary section. C++
programs appear to use this, I believe for vtables and type_info.

This diff also makes our bind opcode encoding a bit smarter -- we now
encode just the differences between bindings, which will make things
more compact.

I was initially concerned about the performance overhead of iterating
over these relocations, but it turns out that the number of such
relocations is small. A quick analysis of my llvm-project build
directory showed that < 1.3% out of ~7M relocations are RELOC_UNSIGNED
bindings to symbols (including both dynamic and static symbols).

Reviewed By: #lld-macho, smeenai

Differential Revision: https://reviews.llvm.org/D83103
2020-07-02 21:21:01 -07:00
Nico Weber 425fb21e03 ld64.lld: Make janky support for tbd files actually work sometimes
Also fix a bug in the test input that made the test miss this issue.
2020-07-02 15:31:21 -04:00
Nemanja Ivanovic 16989f6f5c [LLD] Add required dependency after shared libs break due to ba5087f130
The dependency on TextAPI was not added and is required for shared
libs builds.
2020-07-02 12:28:17 -05:00
James Henderson 5012ddd5af [ELF][test] Add some additional .eh_frame/.eh_frame_hdr testing
This patch adds a few extra cases to the existing testing for eh_frame
and eh_frame_hdr behaviour in LLD. They all come from a private
testsuite we are trying to migrate to lit.

Reviewed by: grimar, MaskRay

Differential Revision: https://reviews.llvm.org/D82852
2020-07-02 15:51:33 +01:00
Craig Topper 0aad82943a [X86] Enable multibyte NOPs in 64-bit mode for padding/alignment.
The default CPU used by llvm-mc doesn't have the NOPL feature, but
if we know we're compiling in 64-bit mode we should be able to
use nopl.
2020-07-01 23:59:01 -07:00
Nico Weber ba5087f130 ld64.lld: Add janky support for tbd files
With this, a simple hello world links against libSystem.tbd and the
old ld64.lld linker kind of works again with newer SDKs.

The motivation here is to have an arm64 cross linker that's good
enough to be able to run simple configure link checks on non-mac
systems for generating config.h files. Once -flavor darwinnew can
link arm64, we'll switch to that.
2020-07-02 00:05:52 -04:00
Nico Weber 7be1661fc6 lld/MachO: Remove a useless temporary 2020-07-02 00:05:43 -04:00
Jez Ng 7996a1ef70 [lld-macho] Make sure ZeroFill sections are at the end of their segments
Summary:
ld64 does this, and references an internal rdar:// number as an explanation. No
idea what that rdar issue is, but in practice, it seems that not putting a BSS
section at the end can cause subsequent sections in the same segment to be
overwritten with zeroes.

Reviewers: #lld-macho

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D81888
2020-07-01 19:39:29 -07:00
Douglas Yung 6f13299c02 Revert "Update lto.ll test after 3367e9da enabled multibyte NOPs in 64-bit mode."
This reverts commit 79f6a814ab.

Didn't notice that someone had reverted the commit that caused the problem.
2020-07-01 16:34:57 -07:00
Douglas Yung 79f6a814ab Update lto.ll test after 3367e9da enabled multibyte NOPs in 64-bit mode.
This should fix the PS4 linux build bot:
http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-ubuntu-fast/builds/70409
2020-07-01 16:25:25 -07:00
Fangrui Song e6ad78fe05 [ELF] Don't resolve a relocation in .debug_line referencing an ICF folded symbol to the tombstone value
After D81784, we resolve a relocation in .debug_* referencing an ICF folded
section symbol to a tombstone value.

Doing this for .debug_line has a problem (https://reviews.llvm.org/D81784#2116925 ):
.debug_line may describe folded lines as having addresses UINT64_MAX or
some wraparound small addresses.

```
int foo(int x) {
  return x; // line 2
}

int bar(int x) {
  return x; // line 6
}
```

```
Address            Line   Column File   ISA Discriminator Flags
------------------ ------ ------ ------ --- ------------- -------------
0x00000000002016c0      1      0      1   0             0  is_stmt
0x00000000002016c7      2      9      1   0             0  is_stmt
prologue_end
0x00000000002016ca      2      2      1   0             0
0x00000000002016cc      2      2      1   0             0  end_sequence
// UINT64_MAX and wraparound small addresses
0xffffffffffffffff      5      0      1   0             0  is_stmt
0x0000000000000006      6      9      1   0             0  is_stmt
prologue_end
0x0000000000000009      6      2      1   0             0
0x000000000000000b      6      2      1   0             0  end_sequence
0x00000000002016d0      9      0      1   0             0  is_stmt
0x00000000002016df     10      6      1   0             0  is_stmt prologue_end
0x00000000002016e6     11     11      1   0             0  is_stmt
...
```

These entries can confuse debuggers:

gdb before 2020-07-01 (binutils-gdb a8caed5d7faa639a1e6769eba551d15d8ddd9510 "Recognize -1 as a tombstone value in .debug_line")
(can't continue due to a breakpoint in an invalid region of memory):
```
Warning:
Cannot insert breakpoint 1.
Cannot access memory at address 0x6
```
lldb (breakpoint has no effect):
```
(lldb) b 6
Breakpoint 1: no locations (pending).
WARNING:  Unable to resolve breakpoint to any actual locations.
```

This patch special cases .debug_line to not use the tombstone value,
restoring the previous behavior: .debug_line will have entries with the
same addresses (ICF) but different line numbers. A breakpoint on line 2
or 6 will trigger on both functions.

Reviewed By: dblaikie, jhenderson

Differential Revision: https://reviews.llvm.org/D82828
2020-07-01 13:38:16 -07:00
Fangrui Song f5e0ae240f [ELF][test] Fix ppc32-gnu-ifunc.s and remove XFAIL: * 2020-06-30 22:05:51 -07:00
Sam Clegg 73e575a88e [lld][WebAssembly] Give better error message on bad archive member
Include the archive name as well as the member name when an error
is encountered parsing bitcode archives.

Differential Revision: https://reviews.llvm.org/D82884
2020-06-30 21:36:36 -07:00
Reid Kleckner b7402edce3 [PDB] Defer public serialization until PDB writing
This reduces peak memory on my test case from 1960.14MB to 1700.63MB
(-260MB, -13.2%) with no measurable impact on CPU time. I'm currently
working with a publics stream that is about 277MB. Before this change,
we would allocate 277MB of heap memory, serialize publics into them,
hold onto that heap memory, open the PDB, and commit into it.  After
this change, we defer the serialization until commit time.

In the last change I made to public writing, I re-sorted the list of
publics multiple times in place to avoid allocating new temporary data
structures. Deferring serialization until later requires that we don't
reorder the publics. Instead of sorting the publics, I partially
construct the hash table data structures, store a publics index in them,
and then sort the hash table data structures. Later, I replace the index
with the symbol record offset.

This change also addresses a FIXME and moves the list of global and
public records from GSIHashStreamBuilder to GSIStreamBuilder. Now that
publics aren't being serialized, it makes even less sense to store them
as a list of CVSymbol records. The hash table used to deduplicate
globals is moved as well, since that is specific to globals, and not
publics.

Reviewed By: aganea, hans

Differential Revision: https://reviews.llvm.org/D81296
2020-06-30 11:28:04 -07:00
Fangrui Song d94526bb5f [ELF] --warn-backrefs: check that D79300 fixed an issue due to `mb = {}`
D79300 forgot to change `getBuffer().empty()` in LazyObjFile::parse to
`fetched`. This caused incorrect iterating after the current LazyObjFile was
fetched. This issue is benign and can just cause loss of "undefined symbols"
and "backward reference" diagnostics.

Before D79300 `mb = {}` caused --warn-backrefs-exclude to be useless for
a fetched LazyObjFile.

Add two test cases.
2020-06-26 20:31:47 -07:00
Dan Gohman 46a3268312 [WebAssembly] Add warnings for -shared and -pie
The meaning of -shared and -pie are expected to be changed in the
future when Module Linking-style libraries are implemented. Begin
issuing warnings to give people a heads-up that they will be changing.

For compatibility with Emscripten, add a --experimental-pic flag which
disables these warnings.

Differential Revision: https://reviews.llvm.org/D81760
2020-06-25 15:55:46 -07:00
Wouter van Oortmerssen b9a539c010 [WebAssembly] Adding 64-bit versions of __stack_pointer and other globals
We have 6 globals, all of which except for __table_base are 64-bit under wasm64.

Differential Revision: https://reviews.llvm.org/D82130
2020-06-25 15:52:44 -07:00
Fangrui Song 40bc99538c [lld-macho] Remove using namespace llvm::MachO
llvm/include/llvm/TextAPI/MachO/ inappropriately uses the llvm::MachO namespace (this is for BinaryFormat and Object) and causes conflicts in some MSVC builds::

http://lab.llvm.org:8011/builders/sanitizer-windows/builds/65324/steps/stage%201%20build/logs/stdio

Removing `using namespace llvm::MachO` should decrease name collisions.
2020-06-24 13:46:13 -07:00
Fangrui Song 18db086dca [lld-macho] Use namespace qualifiers (macho::) instead of `namespace lld { namespace macho {`
See https://llvm.org/docs/CodingStandards.html#use-namespace-qualifiers-to-implement-previously-declared-functions
Similar to D79982.

Reviewed By: #lld-macho, int3

Differential Revision: https://reviews.llvm.org/D82432
2020-06-24 12:34:06 -07:00