Commit Graph

7116 Commits

Author SHA1 Message Date
Fangrui Song cebb0a64b4 [ELF][ARM] Improve error message for unknown relocation
Like rLLD354040.

Before: `error: unrecognized relocation Unknown (254)`
Now:    `error: unknown relocation (254) against symbol foo`
2021-11-08 12:39:08 -08:00
David Blaikie 78758026e2 Fix lld test after dwarfdump array syntax change 2021-11-05 23:00:29 -07:00
Fangrui Song 26a8ceba3e [llvm-readobj] Display DT_RELRSZ/DT_RELRENT as " (bytes)"
to match RELSZ/RELENT.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D113206
2021-11-05 10:02:49 -07:00
Fangrui Song 005456e5fc [lld-macho] Fix an assertion failure when -u specifies an undefined section$start symbol
This matches ld64. Also improve the test for `-dead_strip`.

Reviewed By: #lld-macho, Jez Ng

Differential Revision: https://reviews.llvm.org/D113147
2021-11-04 21:28:33 -07:00
Keith Smiley e7fdff403e [lld-macho] Silently ignore the -objc_abi_version
This undocumented ld64 flag, based on the most recent ld64 source dump
from Xcode 12, only applies to i386. It seems like on all newer
architectures this behavior is the default.

Reviewed By: #lld-macho, int3

Differential Revision: https://reviews.llvm.org/D113070
2021-11-03 22:16:09 -07:00
Keith Smiley 6629ec3ecc [lld-macho] Implement -arch_errors_fatal
By default with ld64, architecture mismatches are just warnings, then
this flag can be passed to make these fail. This matches that behavior.

Reviewed By: int3, #lld-macho

Differential Revision: https://reviews.llvm.org/D113082
2021-11-03 22:01:53 -07:00
Jez Ng 4ae8c83104 [lld-macho][nfc] Remove unnecessary -pie flags in tests
D101513 means that we no longer need to specify `-pie` in most of our
test RUN commands. Let's clean up the unused flags so as not to confuse
future test writers.

Reviewed By: #lld-macho, oontvoo, MaskRay

Differential Revision: https://reviews.llvm.org/D113114
2021-11-04 00:02:03 -04:00
Keith Smiley 4313c56aa3 [lld-macho] Enable search-paths tests on macOS
I'm not sure what the history is here but this test passes on macOS
today. It seems like we should unify these tests if they need to run
cross platform.

Reviewed By: #lld-macho, int3

Differential Revision: https://reviews.llvm.org/D113085
2021-11-03 12:01:36 -07:00
Nico Weber 64c1734438 [lld/mac] Write -v output to stderr
This matches ld64, and it's conceivable that projects try to read
this information off stderr for that reason.

--version keeps writing to stdout.

Differential Revision: https://reviews.llvm.org/D113020
2021-11-02 13:59:14 -04:00
Vy Nguyen d7e5393af4 [lld-macho] Remove no_dtrace_dof from un-implemented group.
One fewer warning.
In practice, lld already "implements" it. (ie., it does not do dtrace-dof processing ever).

Reviewed By: #lld-macho, thakis

Differential Revision: https://reviews.llvm.org/D112934
2021-11-02 12:36:08 -04:00
Shoaib Meenai 7a4b27609d [lld] Add test suite mode for running LLD main twice
LLD_IN_TEST determines how many times each port's `main` function is
run in each LLD process, and setting LLD_IN_TEST=2 (or higher) is useful
for checking if we're cleaning up and resetting global state correctly.
Add a test suite parameter to enable this easily. There's work in
progress to remove global state (e.g. D108850), but this seems useful in
the interim.

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D112898
2021-11-01 14:26:54 -07:00
Shoaib Meenai 264d3b6d4e [MachO] Use error instead of fatal for missing -arch
`fatal` should only be used for malformed inputs according to
ErrorHandler.h; `error` is more appropriate for missing arguments,
accompanied by a check to bail out early in case of the error. Some
tests need to be adjusted accordingly.

Makes `lld/test/MachO/arch.s` pass with `LLD_IN_TEST=2`.

Reviewed By: #lld-macho, int3

Differential Revision: https://reviews.llvm.org/D112879
2021-10-31 16:31:21 -07:00
Nico Weber f964ca896f [lld/coff] Add parsing for /pdbpagesize: flag
It's not used for anything yet, but we now accept `/pdbpagesize:4096`
(the default behavior) and we give arguably more useful diagnostics
for other values.

It's plumbed through to the MSF layer, so just uncommenting out
the bit in DriverUtils.cpp that rejects args other than 4096 is enough
to try other values.

Differential Revision: https://reviews.llvm.org/D112871
2021-10-31 18:36:23 -04:00
Fangrui Song 9f8ffaaa0b [ELF] Replace "symbol '...' has no type" diagnostic with "relocation ... cannot be used against symbol '...'"
The "symbol 'foo' has no type" diagnostic tries to inform that copy
relocation/canonical PLT entry cannot be used, but the diagnostic is often
incorrect and confusing.
2021-10-31 13:12:26 -07:00
Fangrui Song 55e69ece72 [ELF] Remove -Wl,-z,notext hint
The hint does not pull its weight:

* adding -Wl,-z,notext often won't work (relocation types other than `symbolRel`, e.g. `R_AARCH64_LDST32_ABS_LO12_NC`)
* for pure (no assembly) C/C++ projects, the "-fPIC" hint is sufficient
2021-10-31 12:10:43 -07:00
Nico Weber 2d48b19136 [lld/mac] Fix mislink with ICF
When comparing relocations against two symbols, ICF's equalsConstant() did not
look at the value of the two symbols. With subsections_via_symbols, the value
is usually 0 but not always: In particular, it isn't 0 for constants in string
and literal sections. Since we ignored the value, comparing two constant string
symbols or two literal symbols always compared the 0th's element, so functions
in the same TU always compared as equal.

This can cause mislinks, and, with -dead_strip, crashes.

Fixes PR52349, see that bug for lots of details and examples of mislinks.

While here, make the existing assembly in icf-literals.s a bit more realistic
(use leaq instead of movq with strings, and use foo(%rip) instead of
foo@gotpcrel(%rip)). This has no interesting effect, it just maybe makes the
test look a bit less surprising.

Differential Revision: https://reviews.llvm.org/D112862
2021-10-30 18:58:59 -04:00
Sam Clegg 182b72aa48 [lld][WebAssembly] Generate TLS relocation code also when linking statically
Previously relocations were only generated for PIC output, but
relocations for TLS GOT entries are always needed when shared
memory is enabled, not just in PIC mode.

This means that the `__wasm_apply_global_tls_relocs` is now
generated even for statically linked (non-PIC) output.  Without
this the globals that hold the addresses of TLS symbols are
not set correctly.

Differential Revision: https://reviews.llvm.org/D112833
2021-10-29 13:26:35 -07:00
Jez Ng 6c2f26a159 [lld-macho] -all_load and -ObjC should not affect LC_LINKER_OPTION flags
In particular, they should not cause archives to be eagerly loaded. This
matches ld64's behavior.

Fixes PR52246.

Reviewed By: #lld-macho, thakis

Differential Revision: https://reviews.llvm.org/D112756
2021-10-29 11:00:28 -04:00
Fangrui Song e39c138f45 [ELF] Implement TLSDESC for x86-32
`-z rela` is also supported.

Tested with:

```
cat > ./a.c <<eof
#include <assert.h>
int foo();
int bar();
int main() {
  assert(foo() == 2);
  assert(foo() == 4);
  assert(bar() == 2);
  assert(bar() == 4);
}
eof

cat > ./b.c <<eof
#include <stdio.h>
__thread int tls0;
extern __thread int tls1;
int foo() { return ++tls0 + ++tls1; }
static __thread int tls2, tls3;
int bar() { return ++tls2 + ++tls3; }
eof

echo '__thread int tls1;' > ./c.c

sed 's/        /\t/' > ./Makefile <<'eof'
.MAKE.MODE = meta curDirOk=true

CC := gcc -m32 -g -fpic -mtls-dialect=gnu2
LDFLAGS := -m32 -Wl,-rpath=.

all: a0 a1 a2

run: all
        ./a0 && ./a1 && ./a2

c.so: c.o; ${LINK.c} -shared $> -o $@
bc.so: b.o c.o; ${LINK.c} -shared $> -o $@
b.so: b.o c.so; ${LINK.c} -shared $> -o $@

a0: a.o b.o c.o; ${LINK.c} $> -o $@
a1: a.o b.so; ${LINK.c} $> -o $@
a2: a.o bc.so; ${LINK.c} $> -o $@
eof
```
and glibc `elf/tst-gnu2-tls1`.

`/usr/local/bin/ld` points to the freshly built `lld`.

`bmake run && bmake CFLAGS=-O1 run` => ok.

Differential Revision: https://reviews.llvm.org/D112582
2021-10-28 17:52:03 -07:00
Sam Clegg 1eb79e732c [lld][WebAssembly] Initialize bss segments using memory.fill
Previously we were relying on the dynamic loader to take care of this
but it simple and correct for us to do it here instead.

Now we initialize bss segments as part of `__wasm_init_memory` at the
same time we initialize passive segments.

In addition we extent the us of `__wasm_init_memory` outside of shared
memory situations.  Specifically it is now used to initialize bss
segments when the memory is imported.

Differential Revision: https://reviews.llvm.org/D112667
2021-10-28 17:15:08 -07:00
Sam Clegg 50bfc45109 [lld][WebAssemlby] Always enable mutable-globals feature in PIC mode
This works around an issue where the feature can be forgotten
in the case of LTO + object file with no functions.

See: https://bugs.llvm.org/show_bug.cgi?id=52339

Differential Revision: https://reviews.llvm.org/D112769
2021-10-28 16:24:54 -07:00
Sam Clegg 28848e9e1b [lld][WebAssembly] Handle duplicate archive member names in ThinLTO
This entire change, including the test case, comes almost verbatim
from the ELF driver.

Fixes: https://github.com/emscripten-core/emscripten/issues/12763

Differential Revision: https://reviews.llvm.org/D112723
2021-10-28 11:48:04 -07:00
Fangrui Song 2b1e32410c [ELF] Change common diagnostics to report both object file location and source file location
Many diagnostics use `getErrorPlace` or `getErrorLocation` to report a location.
In the presence of line table debug information, `getErrorPlace` uses a source
file location and ignores the object file location. However, the object file
location is sometimes more useful.

This patch changes "undefined symbol" and "out of range" diagnostics to report
both object/source file locations. Other diagnostics can use similar format if
needed.

The key idea is to let `InputSectionBase::getLocation` report the object file
location and use `getSrcMsg` for source file/line information. `getSrcMsg`
doesn't leverage `STT_FILE` information yet, but I think the temporary lack of
the functionality is ok.

For the ARM "branch and link relocation" diagnostic, I arbitrarily place the
source file location at the end of the line. The diagnostic is not very common
so its formatting doesn't need to be pretty.

Differential Revision: https://reviews.llvm.org/D112518
2021-10-28 09:38:45 -07:00
Vincent Lee d54360cd32 [lld-macho] Implement -S
There are a couple internal builds that require the use of this flag.

Reviewed By: #lld-macho, int3

Differential Revision: https://reviews.llvm.org/D112594
2021-10-27 17:09:57 -07:00
Nico Weber 7f369304df [lld/mac] Don't crash on undefined symbols with --icf=all
ICF runs before relocation processing, but undefined symbol errors
are only emitted during relocation processing.

So just ignore Undefineds during ICF (instead of crashing) -- lld
will emit an error once ICF is done.

Fixes PR52330.

Differential Revision: https://reviews.llvm.org/D112643
2021-10-27 16:20:10 -04:00
Jez Ng b7e12ca7aa [lld-macho] If export_size is zero, export_off must be zero
Otherwise tools like codesign_allocate will choke. We were already
handling this correctly for the other DYLD_INFO sections.

Doing this correctly is a bit subtle: we don't know if export_size will
be zero until we have run `ExportSection::finalizeContents()`. However,
we must still add the ExportSection to the `__LINKEDIT` segment in order
that it gets sorted during `sortSectionsAndSegments()`.

Reviewed By: #lld-macho, oontvoo

Differential Revision: https://reviews.llvm.org/D112589
2021-10-27 14:58:42 -04:00
Nico Weber 6503a68565 [lld/mac] Don't assert when ICFing arm64 code
WordLiteralSection dedupes literals by content.
WordLiteralInputSection::getOffset() used to read a literal at the passed-in
offset and look up this value in the deduping map to find the offset of the
deduped value.

But it's possible that (e.g.) a 16-byte literal's value is accessed 4 bytes in.
To get the offset at that address, we have to get the deduped value at offset 0
and then apply the offset 4 to the result.

(See also WordLiteralSection::finalizeContents() which fills in those maps.)

Only a problem on arm64 because in x86_64 the offset is part of the instruction
instead of a separate ARM64_RELOC_ADDEND relocation. (See bug for more details.)

Fixes PR51999.

Differential Revision: https://reviews.llvm.org/D112584
2021-10-27 14:02:07 -04:00
Sam Clegg 1aeb4c4a43 [lld][WebAssebmly] Convert tests to use disassembly. NFC
Differential Revision: https://reviews.llvm.org/D112590
2021-10-27 10:34:52 -07:00
Fangrui Song 35c3f5610c [ELF][X86] Write R_X86_64_TLSDESC addends with -z rel
Similar to D100544 for AArch64.

Reviewed By: arichardson

Differential Revision: https://reviews.llvm.org/D112592
2021-10-27 09:35:30 -07:00
Jez Ng 1d2a4cd57d [lld-macho] Fix compact-unwind-bad-reloc.s test
Broken by a9353dbe51.

Now that the functions point to the compact unwind entries, instead of
the other way around, we need to perform the "invalid reference" check
in a different place.

This change was originally part of the stacked diff D109946, but should
have been included as part of D109945.
2021-10-26 18:59:12 -04:00
Jez Ng 002eda7056 [lld-macho] Associate compact unwind entries with function symbols
Compact unwind entries (CUEs) contain pointers to their respective
function symbols. However, during the link process, it's far more useful
to have pointers from the function symbol to the CUE than vice versa.
This diff adds that pointer in the form of `Defined::compactUnwind`.

In particular, when doing dead-stripping, we want to mark CUEs live when
their function symbol is live; and when doing ICF, we want to dedup
sections iff the symbols in that section have identical CUEs. In both
cases, we want to be able to locate the symbols within a given section,
as well as locate the CUEs belonging to those symbols. So this diff also
adds `InputSection::symbols`.

The ultimate goal of this refactor is to have ICF support dedup'ing
functions with unwind info, but that will be handled in subsequent
diffs. This diff focuses on simplifying `-dead_strip` --
`findFunctionsWithUnwindInfo` is no longer necessary, and
`Defined::isLive()` is now a lot simpler. Moreover, UnwindInfoSection no
longer has to check for dead CUEs -- we simply avoid adding them in the
first place.

Additionally, we now support stripping of dead LSDAs, which follows
quite naturally since `markLive()` can now reach them via the CUEs.

Reviewed By: #lld-macho, gkm

Differential Revision: https://reviews.llvm.org/D109944
2021-10-26 16:04:15 -04:00
Jez Ng 622150ad5f [lld-macho] Put GOT into `__DATA` segment where appropriate
We were previously always emitting the GOT into `__DATA_CONST`, even for
target platforms where it should end up in `__DATA`.

I stumbled onto this while trying to use the `class-dump` tool -- with
the wrong segment names, it fails to locate the ObjC runtime info and
therefore fails to dump any classes.

Reviewed By: #lld-macho, oontvoo

Differential Revision: https://reviews.llvm.org/D112500
2021-10-26 11:38:01 -04:00
Vy Nguyen e5fb79b314 [lld-macho] Make test produce the dead.o and live.o that are used below.
Follow up fix to breakages in D112485
2021-10-25 22:10:24 -04:00
Vy Nguyen 46ef187dcc [lld-macho] Fix incremental build (again) from D112485 2021-10-25 21:51:34 -04:00
Jez Ng d3ddd569eb [lld-macho] Fix incremental builds 2021-10-25 20:51:05 -04:00
Jez Ng 413e249a47 [lld-macho][nfc] Test that we don't emit undef symbol errors for dead code
This is what ld64 does too, so we have parity here (though I think ld64
still removes dead code more effectively than we do...)

Reviewed By: #lld-macho, thakis

Differential Revision: https://reviews.llvm.org/D112485
2021-10-25 19:05:39 -04:00
Fangrui Song 25da870057 [ELF] Remove irrelevant group signature hack working around old gold -r 2021-10-25 15:09:08 -07:00
Fangrui Song 43753f8f9d [ELF] Remove irrelevant SHT_INIT_ARRAY/SHT_FINI_ARRAY hack
The hack is irrelevant for two reasons:

* binutils 2.24 is quite old and cannot handle R_X86_64_REX_GOTPCRELX from 2016 onwards anyway
* `canMergeToProgbits` allows combining SHT_INIT_ARRAY/SHT_FINI_ARRAY into SHT_PROGBITS
2021-10-25 14:23:05 -07:00
Fangrui Song 6506907a0a [ELF] Update comments/diagnostics for -defsym and -image-base to use the canonical two-dash form 2021-10-25 14:01:36 -07:00
Fangrui Song ca8105b76c [ELF][X86] Support R_X86_64_PLTOFF64
For a function call (using the default `-fplt`), GCC `-mcmodel=large` generates an assembly modifier which
leads to an R_X86_64_PLTOFF64 relocation. In real world,
http://git.ageinghacker.net/jitter (used by GNU poke) uses `-mcmodel=large`.

R_X86_64_PLTOFF64's formula is (if preemptible) `L - GOT + A` or (if non-preemptible) `S - GOT + A`
where `GOT` is (confusingly) the address of `.got.plt`

Reviewed By: peter.smith

Differential Revision: https://reviews.llvm.org/D112386
2021-10-25 13:05:17 -07:00
Fangrui Song bf6e259b21 [ELF] Update comments/diagnostics for some long options to use the canonical two-dash form
Rewrite some comments as appropriate.
2021-10-25 12:52:06 -07:00
Fangrui Song 4ae1c2c6f1 [ELF] Delete unneeded hack for discarding empty name local symbol
This actually improves GNU ld compatibility.
Correct assemblers don't create such symbols.

Also simplify the code.
2021-10-25 11:55:31 -07:00
Vy Nguyen 7d549acbb6 [lld-macho][nfc] Rename output binary so it doesn't overwrite existing one
`%t/basics` already exists - it would be nice to be able to examine it afterward

Differential Revision: https://reviews.llvm.org/D112392
2021-10-25 09:55:40 -04:00
Fangrui Song 815a1207bf [ELF] Remove ignored options that likely nobody uses
GNU ld doesn't support `--no-pic-executable`.

`-p` has been removed from likely the only use case (Linux kernel) for over 2.5 years: https://git.kernel.org/linus/091bb549f7722723b284f63ac665e2aedcf9dec9

`--no-add-needed` was the pre-binutils-2.23 spelling for `--no-copy-dt-needed-entries`.
The legacy alias is irrelevant in 2021.
2021-10-24 18:29:45 -07:00
Vy Nguyen 236197e2d0 [lld-macho] Implement -oso_prefix
https://bugs.llvm.org/show_bug.cgi?id=50229

Differential Revision: https://reviews.llvm.org/D112291
2021-10-22 16:32:42 -04:00
Jez Ng 77fdc0e56b [lld-macho] Simplify lc-linker-option.ll and re-enable it on Windows
While attempting to simplify it, I discovered a concerning discrepancy
between our handling of LC_LINKER_OPTION vs ld64's. In particular, ld64
does not appear to check for `-all_load` nor `-ObjC` when processing
those options. Thus, if/when we fix this behavior, no duplicate symbol
error will be expected regardless of the use-after-free. As such, I've
removed the test logic that tries to induce the duplicate symbol error.
We can just rely on ASAN to do the verification.

In order to make the test run on Windows, I've removed the symlink
logic. Both ld64 and LLD handle this un-symlinked framework just fine.

I also capitalized the framework name, since that's the typical
convention.

Reviewed By: #lld-macho, oontvoo

Differential Revision: https://reviews.llvm.org/D112195
2021-10-21 11:23:44 -04:00
Igor Kudrin 1302fdc233 [ELF] Avoid adding an orphan section to a less suitable segment
If segments are defined in a linker script, placing an orphan section
before the found closest-rank section can result in adding it in a
previous segment and changing flags of that segment. This happens if
the orphan section has a lower sort rank than the found section. To
avoid that, the patch forces orphan sections to be moved after the
found section if segments are explicitly defined.

Differential Revision: https://reviews.llvm.org/D111717
2021-10-21 11:38:39 +07:00
Jez Ng 9ef55ddc3f [lld-macho] Temporarily disable lc-linker-option.ll on Windows
It's currently using a symlink, which is not supported on Windows.
2021-10-20 20:05:30 -04:00
Kaining Zhong aab0f2264a [lld-macho] Fix dangling string reference when adding frameworks
In Driver.cpp, addFramework used std::string instance to represent the path of a framework, which will be freed after the function returns. However, this string is stored in loadedArchive, which will be used later to compare with path of newly added frameworks. This caused https://bugs.llvm.org/show_bug.cgi?id=52133. A test is included in this commit to reproduce this bug.

Now resolveDylibPath returns a StringRef instance, and it uses StringSaver to save its data, then returns it to functions on the top. This ensures the resolved framework path is still valid after LC_LINKER_OPTION is parsed.

Reviewed By: int3, #lld-macho, oontvoo

Differential Revision: https://reviews.llvm.org/D111706
2021-10-20 11:21:40 -04:00
Paulo Matos 6d0c7bc17d [WebAssembly] Implementation of table.get/set for reftypes in LLVM IR
This change implements new DAG nodes TABLE_GET/TABLE_SET, and lowering
methods for load and stores of reference types from IR arrays. These
global LLVM IR arrays represent tables at the Wasm level.

Differential Revision: https://reviews.llvm.org/D111154
2021-10-20 10:31:31 +02:00