178 Commits

Author SHA1 Message Date
Fangrui Song
861bd36bce [ELF] Pass Ctx & to Symbol::getVA 2024-10-19 20:32:58 -07:00
Fangrui Song
fe8af49a1b [ELF] Pass Ctx & to Defined & CommonSymbol 2024-10-20 01:38:16 +00:00
Fangrui Song
2c5dd03f55 [ELF] Pass Ctx & to check* 2024-10-13 11:14:40 -07:00
Fangrui Song
0dbc85a59f [ELF] Pass Ctx & to Arch-specific code 2024-10-13 11:08:06 -07:00
Fangrui Song
002ca63b3f [ELF] Pass Ctx & to (read|write)(16|64) 2024-10-13 10:47:18 -07:00
Fangrui Song
38dfcd9ac9 [ELF] Pass Ctx & to read32/write32 2024-10-13 10:37:47 -07:00
Fangrui Song
dbd197118d [ELF] Pass Ctx & to Symbol 2024-10-11 23:34:43 -07:00
Fangrui Song
e1a073c9d9 [ELF] Change Ctx::target to unique_ptr (#111260)
also rename `TargetInfo *getXXXTargetInfo` to `void setXXXTargetInfo`
and change it to set `ctx.target`. This ensures that when `ctx` becomes
a local variable, two lld invocations will not reuse the function-local
static variable.

---

Reland after commit c35214c131c0bc7f54dc18ceb75c75cba89f58ee
([ELF] Initialize TargetInfo members).
2024-10-07 23:14:02 -07:00
Paul Kirth
2ca850111f
Revert "[ELF] Change Ctx::target to unique_ptr (#111260)" (#111449)
This patch seems to be breaking the windows build bots.
https://lab.llvm.org/buildbot/#/builders/63/builds/1953

We also see this in Fuchsia's Linux CI:
https://fxbug.dev/372010530

This reverts commit 4ec06b17435e32ece5e1aa2bc8a6d26dbf0bb312.
2024-10-07 15:43:01 -07:00
Fangrui Song
4ec06b1743
[ELF] Change Ctx::target to unique_ptr (#111260)
also rename `TargetInfo *getXXXTargetInfo` to `void setXXXTargetInfo`
and change it to set `ctx.target`. This ensures that when `ctx` becomes
a local variable, two lld invocations will not reuse the function-local
static variable.
2024-10-06 21:47:13 -07:00
Fangrui Song
cfd3289a1f [ELF] Pass Ctx & to some free functions 2024-10-06 19:36:21 -07:00
Fangrui Song
acb2b1e779 [ELF] Pass Ctx & to Symbols 2024-10-06 16:59:04 -07:00
Fangrui Song
2b5cb1bf62 [ELF] getRelocTargetVA: pass Ctx and Relocation. NFC 2024-10-06 16:34:09 -07:00
Fangrui Song
6d03a69034 [ELF] Pass Ctx & to Arch/ 2024-10-06 00:14:12 -07:00
Fangrui Song
c3e4998c0b [ELF] Pass Ctx & to TargetInfo. NFC 2024-09-28 21:48:26 -07:00
Fangrui Song
df0864e761 [ELF] Move elf::symtab into Ctx
Remove the global variable `symtab` and add a member variable
(`std::unique_ptr<SymbolTable>`) to `Ctx` instead.

This is one step toward eliminating global states.

Pull Request: https://github.com/llvm/llvm-project/pull/109612
2024-09-23 10:33:43 -07:00
Fangrui Song
1dd9a565ea [ELF] Replace config-> with ctx.arg. in Arch/ 2024-09-21 12:03:18 -07:00
Fangrui Song
e88b7ff016 [ELF] Move InStruct into Ctx. NFC
Ctx was introduced in March 2022 as a more suitable place for such
singletons.

llvm/Support/thread.h includes <thread>, which transitively includes
sstream in libc++ and uses ios_base::in, so we cannot use `#define in ctx.sec`.

`symtab, config, ctx` are now the only variables using
LLVM_LIBRARY_VISIBILITY.
2024-09-15 22:15:02 -07:00
Fangrui Song
b4feb26606 [ELF] Move target to Ctx. NFC
Ctx was introduced in March 2022 as a more suitable place for such
singletons.

Follow-up to driver (2022-10) and script (2024-08).
2024-08-21 23:53:36 -07:00
Fangrui Song
89b1468345 [ELF] Move ppc64noTocRelax to Ctx. NFC
Ctx was introduced in March 2022 as a more suitable place for such
singletons.
2024-08-21 00:10:31 -07:00
Fangrui Song
456c239d77 [ELF] Set ctx.internalFile for PPC64 _savegpr[01]_{14..31} and _restgpr[01]_{14..31}. NFC
Ensure that every InputFile has a non-null file so that we enforce this
in the future.
2024-03-19 18:21:20 -07:00
Fangrui Song
f6455606bb [ELF] Move getSymbol/getRelocTargetSym from ObjFile<ELFT> to InputFile. NFC
This removes lots of unneeded `template getFile<ELFT>()`.
2024-03-10 23:01:26 -07:00
Fangrui Song
4a3f7e798a
[ELF] Internalize enum
g++ -flto has a diagnostic `-Wodr` about mismatched redeclarations,
which even apply to `enum`.

Fix #83529

Reviewers: thesamesam

Reviewed By: thesamesam

Pull Request: https://github.com/llvm/llvm-project/pull/83604
2024-03-01 11:17:22 -08:00
Fangrui Song
43b13341fb
[ELF] Add internal InputFile (#78944)
Based on https://reviews.llvm.org/D45375 . Introduce a new InputFile
kind `InternalKind`, use it for

* `ctx.internalFile`: for linker-defined symbols and some synthesized
`Undefined`
* `createInternalFile`: for symbol assignments and --defsym

I picked "internal" instead of "synthetic" to avoid confusion with
SyntheticSection.

Currently a symbol's file is one of: nullptr, ObjKind, SharedKind,
BitcodeKind, BinaryKind. Now it's non-null (I plan to add an
`assert(file)` to Symbol::Symbol and change `toString(const InputFile
*)`
separately).

Debugging and error reporting gets improved. The immediate user-facing
difference is more descriptive "File" column in the --cref output. This
patch may unlock further simplification.

Currently each symbol assignment gets its own
`createInternalFile(cmd->location)`. Two symbol assignments in a linker
script do not share the same file. Making the file the same would be
nice, but would require non trivial code.
2024-01-22 09:09:46 -08:00
simpal01
3cde1d8000
[ELF] Handle relocations in synthetic .eh_frame with a non-zero offset within the output section (#65966)
When the .eh_frame section is placed at a non-zero
offset within its output section, the relocation
value within .eh_frame are computed incorrectly.

We had similar issue in .ARM.exidx section and it has been
fixed already in https://reviews.llvm.org/D148033.

While applying the relocation using S+A-P,  the value
 of P (the location of the relocation) is getting wrong. 
P is:
  P = SecAddr + rel.offset, But SecAddr points to the
starting address of the outputsection rather than the
starting address of the eh frame section within that
output section.

This issue affects all targets which generates .eh_frame 
section. Hence fixing in all the corresponding targets it affecting.
2023-10-03 10:20:14 +01:00
Amy Kwan
698b45aa90 [PowerPC][lld] Account for additional X-Forms -> D-Form/DS-Forms load/stores when relaxing initial-exec to local-exec
D153645 added additional X-Form load/stores that can be generated for TLS accesses.
However, these added instructions have not been accounted for in lld. As a result,
lld does not know how to handle them and cannot relax initial-exec to local-exec
when the initial-exec sequence contains these additional load/stores.

This patch aims to resolve https://github.com/llvm/llvm-project/issues/64424.

Differential Revision: https://reviews.llvm.org/D158197
2023-08-31 08:45:10 -05:00
Mitch Phillips
ca35a19aca [lld] Synthesize metadata for MTE globals
As per the ABI at
https://github.com/ARM-software/abi-aa/blob/main/memtagabielf64/memtagabielf64.rst,
this patch interprets the SHT_AARCH64_MEMTAG_GLOBALS_STATIC section,
which contains R_NONE relocations to tagged globals, and emits a
SHT_AARCH64_MEMTAG_GLOBALS_DYNAMIC section, with the correct
DT_AARCH64_MEMTAG_GLOBALS and DT_AARCH64_MEMTAG_GLOBALSSZ dynamic
entries. This section describes, in a uleb-encoded stream, global memory
ranges that should be tagged with MTE.

We are also out of bits to spare in the LLD Symbol class. As a result,
I've reused the 'needsTocRestore' bit, which is a PPC64 only feature.
Now, it's also used for 'isTagged' on AArch64.

An entry in SHT_AARCH64_MEMTAG_GLOBALS_STATIC is practically a guarantee
from an objfile that all references to the linked symbol are through the
GOT, and meet correct alignment requirements. As a result, we go through
all symbols and make sure that, for all symbols $SYM, all object files
that reference $SYM also have a SHT_AARCH64_MEMTAG_GLOBALS_STATIC entry
for $SYM. If this isn't the case, we demote the symbol to being
untagged. Symbols that are imported from other DSOs should always be
fine, as they're GOT-referenced (and thus the GOT entry either has the
correct tag or not, depending on whether it's tagged in the defining DSO
or not).

Additionally hand-tested by building {libc, libm, libc++, libm, and libnetd}
on Android with some experimental MTE globals support in the
linker/libc.

Reviewed By: MaskRay, peter.smith

Differential Revision: https://reviews.llvm.org/D152921
2023-07-31 17:07:42 +02:00
serge-sans-paille
984b800a03
Move from llvm::makeArrayRef to ArrayRef deduction guides - last part
This is a follow-up to https://reviews.llvm.org/D140896, split into
several parts as it touches a lot of files.

Differential Revision: https://reviews.llvm.org/D141298
2023-01-10 11:47:43 +01:00
Fangrui Song
c3c9e45312 [ELF] Add InputSectionBase::{addRelocs,relocs} and GotSection::addConstant to add/access relocations
to prepare for changing `relocations` from a SmallVector to a pointer.

Also change the `isec` parameter in `addAddendOnlyRelocIfNonPreemptible` to `GotSection &`.
2022-11-21 04:12:03 +00:00
Fangrui Song
2bf5d86422 [ELF] Change rawData to content() and data() to contentMaybeDecompress()
Clarify data() which may trigger decompression and make it feasible to refactor
the member variable rawData.
2022-11-20 22:43:22 +00:00
Fangrui Song
685b212553 [ELF] Make relocateAlloc target specific. NFC
The target-specific code (AArch64, PPC64) does not fit into the generic code and
adds virtual function overhead. Move relocateAlloc into ELF/Arch/ instead. This
removes many virtual functions (relaxTls*). In addition, this helps get rid of
getRelocTargetVA dispatch and many RelExpr members in the future.
2022-10-17 11:01:11 -07:00
Fangrui Song
3ba60576c5 [ELF] Move PPC64 above. NFC
Prepare for a refactoring.
2022-10-17 10:08:47 -07:00
Fangrui Song
14f996dca8 [ELF] Move inputSections/ehInputSections into Ctx. NFC 2022-10-16 00:49:48 -07:00
Fangrui Song
9f9bab19e3 [ELF] Replace some config->ekind with file->ekind. NFC 2022-10-02 21:27:41 -07:00
Fangrui Song
9c626d4a0d [ELF] Remove symtab indirection. NFC
Add LLVM_LIBRARY_VISIBILITY to remove unneeded GOT and unique_ptr indirection.
2022-10-01 14:46:49 -07:00
Fangrui Song
34fa860048 [ELF] Remove ctx indirection. NFC
Add LLVM_LIBRARY_VISIBILITY to remove unneeded GOT and unique_ptr
indirection. We can move other global variables into ctx without
indirection concern. In the long term we may consider passing Ctx
as a parameter to various functions and eliminate global state as
much as possible and then remove `Ctx::reset`.
2022-10-01 12:06:33 -07:00
Fangrui Song
ec04e45c03 [lld] LLVM_FALLTHROUGH => [[fallthrough]]. NFC
With C++17 there is no Clang pedantic warning or MSVC C5051.
2022-08-07 00:02:35 +00:00
Fangrui Song
97b767eb3b [ELF] Support missing relocations in PPC64::getImplicitAddend() 2022-07-30 10:46:58 -07:00
Fangrui Song
9a572164d5 [ELF] Move InputFiles global variables (memoryBuffers, objectFiles, etc) into Ctx. NFC 2022-06-29 18:53:38 -07:00
Fangrui Song
767e64fc11 [ELF] Support some absolute/PC-relative relocation types for REL format
ctfconvert seems to use REL-format `.rel.SUNW_dof` for 32-bit architectures.
```
Binary file usr/ports/lang/perl5.32/work/perl-5.32.1/dtrace_mini.o matches
[alfredo.junior@dell-a ~/tmp/llvm-bug]$ readelf -r dtrace_mini.o

Relocation section (.rel.SUNW_dof):
r_offset r_info   r_type              st_value st_name
00000184 0000281a R_PPC_REL32         00000000 $dtrace1772974259.Perl_dtrace_probe_load
```

Support R_PPC_REL32 to fix `ld.lld: error: drti.c:(.SUNW_dof+0x4E4): internal linker error: cannot read addend for relocation R_PPC_REL32`.
While here, add some common relocation types for AArch64, PPC, and PPC64.
We perform minimum tests.

Reviewed By: adalava, arichardson

Differential Revision: https://reviews.llvm.org/D120535
2022-02-25 19:25:18 +00:00
Fangrui Song
38fbedab32 [ELF] Don't rely on Symbols.h's transitive inclusion of InputFiles.h. NFC 2022-02-23 20:44:34 -08:00
Fangrui Song
53b59fdc52 [ELF][PPC64] Fix assertion failure for branches to hidden undefined weak for -no-pie
Reported by Stefan Pintilie in D119773.

For a branch to a hidden undefined weak symbol, there is an
`assert(sym->getVA());` failure in PPC64LongBranchTargetSection::writeTo for a
-no-pie link. The root cause is that we unnecessarily create the thunk for the
-no-pie link.

Fix this by changing the condition to just `s.isUndefined()`. See the inline
comment.

Rename ppc64-weak-undef-call.s to ppc64-undefined-weak.s to be consistent with
other architectures.

Reviewed By: sfertile, stefanp

Differential Revision: https://reviews.llvm.org/D119787
2022-02-15 12:57:27 -08:00
Fangrui Song
977a1a523c [ELF] Symbol::replace: use the old nameData/nameSize. NFC
Currently `this->getName() == newSym.getName()`.
By keeping the old nameData/nameSize, newSym's nameData/nameSize will be
ignored. The call sites can avoid calling getName().

printTraceSymbol needs to take the symbol name since `other`'s name is empty.
2022-02-05 16:34:02 -08:00
Fangrui Song
53fc5d9b9a [ELF] Support R_PPC_NONE/R_PPC64_NONE in getImplicitAddend
Similar to f457863ae345d2635026501f5383e0e625869639
2022-02-04 15:13:37 -08:00
Alexandre Ganea
83d59e05b2 Re-land [LLD] Remove global state in lldCommon
Move all variables at file-scope or function-static-scope into a hosting structure (lld::CommonLinkerContext) that lives at lldMain()-scope. Drivers will inherit from this structure and add their own global state, in the same way as for the existing COFFLinkerContext.

See discussion in https://lists.llvm.org/pipermail/llvm-dev/2021-June/151184.html

The previous land f860fe362282ed69b9d4503a20e5d20b9a041189 caused issues in https://lab.llvm.org/buildbot/#/builders/123/builds/8383, fixed by 22ee510dac9440a74b2e5b3fe3ff13ccdbf55af3.

Differential Revision: https://reviews.llvm.org/D108850
2022-01-20 14:53:26 -05:00
Alexandre Ganea
e6b153947d Revert [LLD] Remove global state in lldCommon
It seems to be causing issues on https://lab.llvm.org/buildbot/#/builders/123/builds/8383
2022-01-16 11:03:06 -05:00
Alexandre Ganea
f860fe3622 [LLD] Remove global state in lldCommon
Move all variables at file-scope or function-static-scope into a hosting structure (lld::CommonLinkerContext) that lives at lldMain()-scope. Drivers will inherit from this structure and add their own global state, in the same way as for the existing COFFLinkerContext.

See discussion in https://lists.llvm.org/pipermail/llvm-dev/2021-June/151184.html

Differential Revision: https://reviews.llvm.org/D108850
2022-01-16 08:57:57 -05:00
Fangrui Song
5d3bd7f360 [ELF] Move gotIndex/pltIndex/globalDynIndex to SymbolAux
to decrease sizeof(SymbolUnion) by 8 on ELF64 platforms.

Symbols needing such information are typically 1% or fewer (5134 out of 560520
when linking clang, 19898 out of 5550705 when linking chrome). Storing them
elsewhere can decrease memory usage and symbol initialization time.
There is a ~0.8% saving on max RSS when linking a large program.

Future direction:

* Move some of dynsymIndex/verdefIndex/versionId to SymbolAux
* Support mixed TLSDESC and TLS GD without increasing sizeof(SymbolUnion)

Reviewed By: peter.smith

Differential Revision: https://reviews.llvm.org/D116281
2022-01-09 13:43:27 -08:00
Fangrui Song
d71bb6a409 [ELF] Inline isPPC64SmallCodeModelTocReloc which is only called once. NFC 2021-11-09 20:41:05 -08:00
Fangrui Song
ecc93ed2d7 [ELF] Replace InputBaseSection::{areRelocsRela,firstRelocation,numRelocation} with relSecIdx
For `InputSection` `.foo`, its `InputBaseSection::{areRelocsRela,firstRelocation,numRelocation}` basically
encode the information of `.rel[a].foo`. However, one uint32_t (the relocation section index)
suffices. See the implementation of `relsOrRelas`.

This change decreases sizeof(InputSection) from 184 to 176 on 64-bit Linux.

The maximum resident set size linking a large application (1.2G output) decreases by 0.39%.

Differential Revision: https://reviews.llvm.org/D112513
2021-10-27 09:51:07 -07:00