Commit Graph

5374 Commits

Author SHA1 Message Date
Rui Ueyama 444363e931 Do not call computeIsPreemptible() if its result is discarded. NFC.
llvm-svn: 345208
2018-10-24 22:15:32 +00:00
Rui Ueyama 4664280a9c Add more blank lines so that code doesn't look too dense. NFC.
llvm-svn: 345205
2018-10-24 21:59:58 +00:00
Rui Ueyama 6e33f7ac66 Add a comment for PPC64 .toc and GNU relro.
llvm-svn: 345204
2018-10-24 21:59:48 +00:00
Rui Ueyama aa2948776a Include input section name and output section name in an error message.
Differential Revision: https://reviews.llvm.org/D53645

llvm-svn: 345172
2018-10-24 18:15:40 +00:00
Rui Ueyama 8d76024916 Refactor assignFileOffsets. NFC.
llvm-svn: 345154
2018-10-24 15:47:46 +00:00
Rui Ueyama 6d26ed92cc Split a function. NFC.
llvm-svn: 345143
2018-10-24 14:24:01 +00:00
Rui Ueyama 6e763a36c6 Add parenthese around a bitand.
llvm-svn: 345139
2018-10-24 13:44:51 +00:00
Rui Ueyama ee2b61cfd3 Make a local variable scope narrower. NFC.
llvm-svn: 345138
2018-10-24 13:42:33 +00:00
Martin Storsjo c3095ace86 [ELF] Remove a superfluous semicolon, fixing warnings. NFC.
llvm-svn: 345116
2018-10-24 07:42:06 +00:00
Rui Ueyama 02c7fae348 Move forward declarations to the top of the file and sort.
llvm-svn: 345094
2018-10-23 22:37:14 +00:00
Rui Ueyama b0de6c742a Move a function out of a class because it doesn't depend on any class member. NFC.
llvm-svn: 345093
2018-10-23 22:31:08 +00:00
Rui Ueyama 5a30177ef6 Factor out code to a new function. NFC.
llvm-svn: 345088
2018-10-23 22:03:33 +00:00
Rui Ueyama edc3201b11 Simplify. NFC.
A higher order function `applySyntehtic` can be replaced with a simpler function.

llvm-svn: 345081
2018-10-23 21:17:00 +00:00
Rui Ueyama 660e8721a9 Remove a global variable that is set but not used.
llvm-svn: 345080
2018-10-23 21:00:28 +00:00
Rui Ueyama 29d8639732 Add a comment.
llvm-svn: 345062
2018-10-23 17:52:44 +00:00
Rui Ueyama 42ab6c53f8 Remove a global variable that we can live without.
Out::DebugInfo was used only by GdbIndex class to determine if
we need to create a .gdb_index section, but we can do the same
check without it.

Added a test that this patch doesn't change the existing behavior.

llvm-svn: 345058
2018-10-23 17:39:43 +00:00
Dimitry Andric ad5aab8ddb Don't mess up RelIplt symbols during relocatable processing
Summary:
During upgrading of the FreeBSD source tree with lld 7.0.0, I noticed
that it started complaining about `crt1.o` having an "index past the
end of the symbol table".

Such a symbol table looks approximately like this, viewed with `readelf
-s` (note the `Ndx` field being messed up):

```
Symbol table '.symtab' contains 4 entries:
   Num:    Value  Size Type    Bind   Vis      Ndx Name
     0: 00000000     0 NOTYPE  LOCAL  DEFAULT  UND
     1: 00000000     0 SECTION LOCAL  DEFAULT    1
     2: 00000000     0 NOTYPE  WEAK   HIDDEN  RSV[0xffff] __rel_iplt_end
     3: 00000000     0 NOTYPE  WEAK   HIDDEN  RSV[0xffff] __rel_iplt_start
```

At first, it seemed that recent ifunc relocation work had caused this:
<https://reviews.freebsd.org/rS339351>, but it turned out that it was
due to incorrect processing of the object files by lld, when using `-r`
(a.k.a. --relocatable).

Bisecting showed that rL324421 ("Convert a use of Config->Static") was
the commit where this new behavior began.  Simply reverting it solved
the issue, and the `__rel_iplt` symbols had an index of `UND` again.

Looking at Rafael's commit message, I think he simply missed the
possibility of `--relocatable` being in effect, so I have added an
additional check for it.

I also added a simple regression test case.

Reviewers: grimar, ruiu, emaste, espindola

Reviewed By: ruiu

Subscribers: arichardson, krytarowski, llvm-commits

Differential Revision: https://reviews.llvm.org/D53515

llvm-svn: 345002
2018-10-23 05:53:15 +00:00
Shoaib Meenai c8e9d2b525 [ELF] Handle elf32-littlearm in OUTPUT_FORMAT
We need this to support 32-bit ARM. Add test cases for emulation
handling for this architecture as well.

Differential Revision: https://reviews.llvm.org/D53539

llvm-svn: 344976
2018-10-22 23:56:10 +00:00
Fangrui Song efc0fe5a72 [ELF] Don't warn on two legitimate cases when reading .llvm.call-graph-profile
Summary:
Before, superfluous warnings were emitted for the following two cases:

1) When from symbol was in a discarded section.
  The profile should be thought of as affiliated to the section.
  It makes sense to ignore the profile if the section is discarded.

2) When to symbol was in a shared object.
  The object file containing the profile may not know about the to
  symbol, which can reside in another object file (useful profile) or a
  shared object (not useful as symbols in the shared object are fixed
  and unorderable). It makes sense to ignore the profile from the object
  file.

  Note, the warning when to symbol was undefined was suppressed in
  D53044, which is still useful for --symbol-ordering-file=

This patch silences the warnings. The check is actually more relaxed (no
warnings if either From or To is not Defined) for simplicity and I don't
see a compelling reason to warn on more cases.

Reviewers: ruiu, davidxl, espindola, Bigcheese

Reviewed By: ruiu

Subscribers: emaste, arichardson, llvm-commits

Differential Revision: https://reviews.llvm.org/D53470

llvm-svn: 344974
2018-10-22 23:43:53 +00:00
Rui Ueyama ea8cd00a1d Add OUTPUT_FORMAT linker script directive support.
This patch adds a support for OUTPUT_FORMAT linker script directive.
Since I'm not 100% confident with BFD names you can use in the directive
for all architectures, I added only a few in this patch. We can add
other names for other archtiectures later.

We still do not support triple-style OUTPUT_FORMAT directive, namely,
OUTPUT_FORMAT(bfdname, big, little). If you pass -EL (little endian)
or -EB (big endian) to the linker, GNU linkers pick up big or little
as a BFD name, correspondingly, so that you can use a single linker
script for bi-endian processor. I'm not sure if we really need to
support that, so I'll leave it alone for now.

Note that -m takes precedence over OUTPUT_FORAMT, but we always parse
a BFD name given to OUTPUT_FORMAT for error checking. You cannot write
an invalid name in the OUTPUT_FORMAT directive.

Differential Revision: https://reviews.llvm.org/D53495

llvm-svn: 344952
2018-10-22 20:50:01 +00:00
Fangrui Song e94d8823d9 [ELF][PPC64] Fix a split-stack comment in rLLD344622
The blt- instruction (predicted not to be taken) uses cr7, not the default cr0.

llvm-svn: 344948
2018-10-22 20:30:06 +00:00
Fangrui Song 8bafbfea9d [ELF] Format PPC64.cpp, NFC
Mainly two mis-indented places. The changes are local so should not interfere with in-review revisions

llvm-svn: 344932
2018-10-22 18:20:18 +00:00
Sam Clegg ea65647254 Use llvm::arrayRefFromStringRef
Differential Revision: https://reviews.llvm.org/D53432

llvm-svn: 344888
2018-10-22 08:35:39 +00:00
Alexander Richardson 39adc6df0d Add an addAbsolute static function to Writer.cpp
Summary:
SymbolTable::addAbsolute() was removed in rL344305.
To me this is more readable than the lambda named `Add` and in our
out-of-tree CHERI target we use addAbsolute() in another function.

Reviewers: ruiu, espindola

Reviewed By: ruiu

Subscribers: kristina, emaste, llvm-commits

Differential Revision: https://reviews.llvm.org/D53393

llvm-svn: 344842
2018-10-20 11:12:50 +00:00
Sean Fertile 3acfe400a2 [PPC64] Fix offset checks on rel24 call relocations.
Adjusted the range check on a call instruction from 24 bits signed to
26 bits signed. While the instruction only encodes 24 bits, the target is
assumed to be 4 byte aligned, and the value that is encoded in the instruction
gets shifted left by 2 to form the offset. Also added a check that the offset is
indeed at least 4 byte aligned.

Differential Revision: https://reviews.llvm.org/D53401

llvm-svn: 344747
2018-10-18 15:43:41 +00:00
Sean Fertile 4b5ec7fb80 Reland "[PPC64] Add split - stack support."
Recommitting https://reviews.llvm.org/rL344544 after fixing undefined behavior
from left-shifting a negative value. Original commit message:

This support is slightly different then the X86_64 implementation in that calls
to __morestack don't need to get rewritten to calls to __moresatck_non_split
when a split-stack caller calls a non-split-stack callee. Instead the size of
the stack frame requested by the caller is adjusted prior to the call to
__morestack. The size the stack-frame will be adjusted by is tune-able through a
new --split-stack-adjust-size option.

llvm-svn: 344622
2018-10-16 17:13:01 +00:00
Sean Fertile 831a1336ff Revert "[PPC64] Add split - stack support."
This reverts commit https://reviews.llvm.org/rL344544, which causes failures on
a undefined behaviour sanitizer bot -->
lld/ELF/Arch/PPC64.cpp:849:35: runtime error: left shift of negative value -1

llvm-svn: 344551
2018-10-15 20:20:28 +00:00
Sean Fertile 795cc9332b [PPC64] Add split - stack support.
This support is slightly different then the X86_64 implementation in that calls
to __morestack don't need to get rewritten to calls to __moresatck_non_split
when a split-stack caller calls a non-split-stack callee. Instead the size of
the stack frame requested by the caller is adjusted prior to the call to
__morestack. The size the stack-frame will be adjusted by is tune-able through a
new --split-stack-adjust-size option.

Differential Revision: https://reviews.llvm.org/D52099

llvm-svn: 344544
2018-10-15 19:05:57 +00:00
Sid Manning 6df0759aad [ELF][HEXAGON] Let input determine e_flag.
Differential Revision: https://reviews.llvm.org/D53204

llvm-svn: 344518
2018-10-15 14:44:52 +00:00
George Rimar ee981860a8 [LLD][ELF] - Check options before processing the -v/-version options.
This is https://bugs.llvm.org/show_bug.cgi?id=39289.

Currently both gold and bfd report errors about invalid options values
even with -v/-versions. But LLD does not.

This makes complicated to check the options available when LLD is used.

Patch makes LLD behavior to be consistent with GNU linkers.

Differential revision: https://reviews.llvm.org/D53278

llvm-svn: 344514
2018-10-15 14:21:43 +00:00
Rui Ueyama 3d354081e0 Simplify. NFC.
- Removed redundant `llvm::`
 - Typedef a long type name
 - Initialize members by member initializers

llvm-svn: 344427
2018-10-12 22:44:06 +00:00
Rui Ueyama f3fad55787 Remove `Type` parameter from SymbolTable::insert(). NFC.
`Type` parameter was used only to check for TLS attribute mismatch,
but we can do that when we actually replace symbols, so we don't need
to type as an argument. This change should simplify the interface of
the symbol table a bit.

llvm-svn: 344394
2018-10-12 18:29:18 +00:00
Rui Ueyama 2e9d40d5f4 [lld] Add more complete support for the INCLUDE command.
Patch by Ian Tessier.

This change adds INCLUDE support to the MEMORY and SECTION commands, and
to output sections, as per:

https://sourceware.org/binutils/docs/ld/File-Commands.html#File-Commands

Differential Revision: https://reviews.llvm.org/D52951

llvm-svn: 344368
2018-10-12 17:07:32 +00:00
George Rimar 4cb05713de [ELF] - Remove unused variable. NFC.
It triggered a bot failture somehow today:
http://lab.llvm.org:8011/builders/lld-perf-testsuite/builds/7993

llvm-svn: 344344
2018-10-12 13:39:35 +00:00
George Rimar fa91327b51 [ELF] - Remove dead declaration. NFC.
MipsGotSection::FileGot::isOverflow()
was a dead declararion.

llvm-svn: 344342
2018-10-12 13:25:25 +00:00
Rui Ueyama b0d8502049 Remove SymbolTable::addAbsolute().
addAbsolute() could be implemented as a non-member function.

llvm-svn: 344305
2018-10-11 22:15:41 +00:00
Rui Ueyama 936cfa86e5 Remove `else` after `return`.
llvm-svn: 344302
2018-10-11 21:57:52 +00:00
Eli Friedman 8b44cc21c6 [ELF] Fix link failure with Android compressed relocation support.
Android uses a compressed relocation format, which means the size of the
relocation section isn't predictable based on the number of relocations,
and can vary if the layout changes in any way. To deal with this, the
linker normally runs multiple passes until the layout converges.

The layout should converge if the size of the compressed
relocation section increases monotonically: if the size of an encoded
offset increases by one byte, the larget value which can be encoded is
multiplied by 128, so the representable offsets grow much faster than
the size of the section itself.

The problem here is that there is no code to ensure the size of the
section doesn't decrease.  If the size of the relocation section
decreases, the relative offsets can increase due to alignment
restrictions, so that can force the size of the relocation section to
increase again.  The end result is an infinite loop; the loop gets cut
off after 10 iterations with the message "thunk creation not
converged".

To avoid this issue, this patch adds padding to the end of the
relocation section if its size would decrease.  The extra
padding is harmless because of the way the format is defined:
decoding stops after it reaches the number of relocations specified
in the section's header.

Differential Revision: https://reviews.llvm.org/D53003

llvm-svn: 344300
2018-10-11 21:43:06 +00:00
Rui Ueyama 2600e0946b Rename SymbolTable::addRegular -> SymbolTable::addDefined.
We have addAbsolute, addBitcode, addCommon, etc. addRegular looked a
bit inconsistent.

llvm-svn: 344294
2018-10-11 20:43:01 +00:00
Rui Ueyama cf41adaaa0 Remove unused default arguments.
llvm-svn: 344292
2018-10-11 20:38:34 +00:00
Rui Ueyama c7497d3ac5 Remove SymbolTable::addUndefined<ELF32LE>(StringRef).
Because we can implement the function as a non-member function.

llvm-svn: 344290
2018-10-11 20:34:29 +00:00
George Rimar 3368643f5e [ELF] - Set sh_info and sh_link for .rela.plt sections.
This is https://bugs.llvm.org/show_bug.cgi?id=37538,

Currently, LLD may set both sh_link and sh_info for
.rela.plt section to zero when we have only .rela.iplt section part used.

ELF spec (https://docs.oracle.com/cd/E19683-01/816-1386/chapter6-94076/index.html)
says that for SHT_REL and SHT_RELA, sh_link references the associated symbol table
and sh_info the "section to which the relocation applies."

When we set the sh_link field, for the regular case we use the .dynsym index.
For .rela.iplt sections, it is unclear what is the associated symbol table,
because R_*_RELATIVE relocations do not use symbol names and we might have no
.dynsym section at all so this patch uses .symtab section index.

Differential revision: https://reviews.llvm.org/D52830

llvm-svn: 344226
2018-10-11 08:25:35 +00:00
Rui Ueyama 3c4344810a Make a member function private and rename it to avoid function overloading.
llvm-svn: 344196
2018-10-10 22:49:29 +00:00
Fangrui Song 11ca54f49c [ELF] Don't warn on undefined symbols if UnresolvedPolicy::Ignore is used
Summary:
Add a condition UnresolvedPolicy::Ignore to elf::warnUnorderedSymbol to suppress Sym->isUndefined() warnings from both

1) --symbol-ordering-file=
2) .llvm.call-graph-profile

If --unresolved-symbols=ignore-all is used,

  no "undefined symbol" error/warning is emitted. It makes sense to not warn unorderable symbols.

Otherwise,

  If an executable is linked, the default policy UnresolvedPolicy::ErrorOrWarn will issue a "undefined symbol" error. The unorderable symbol warning is redundant.

  If a shared object is linked, it is possible that only part of object files are used and some symbols are left undefined. The warning is not very necessary.
    In particular for .llvm.call-graph-profile, when linking a shared object, a call graph profile may contain undefined symbols. This case generated a warning before but it will be suppressed by this patch.

Reviewers: ruiu, davidxl, espindola

Reviewed By: ruiu

Subscribers: grimar, emaste, arichardson, llvm-commits

Differential Revision: https://reviews.llvm.org/D53044

llvm-svn: 344195
2018-10-10 22:48:57 +00:00
Rui Ueyama 9ae88c64fa Eliminate dependency to formatv(). NFC.
llvm-svn: 344177
2018-10-10 20:29:29 +00:00
Fangrui Song 2043a58abe Adapt OptTable::PrintHelp change in D51009
Summary: Before, OptTable::PrintHelp append "[options] <inputs>" to its parameter `Help`. It is more flexible to change its semantic to `Usage` and let user customize the usage line.

Reviewers: rupprecht, ruiu, espindola

Reviewed By: rupprecht

Subscribers: emaste, sbc100, arichardson, aheejin, llvm-commits

Differential Revision: https://reviews.llvm.org/D53054

llvm-svn: 344099
2018-10-10 00:15:36 +00:00
Rui Ueyama 71cdbb7fe6 Merge two overloaded functions into one function. NFC.
llvm-svn: 344089
2018-10-09 22:44:53 +00:00
Rui Ueyama e65cb4889e Return early. NFC.
llvm-svn: 344088
2018-10-09 22:44:42 +00:00
Rui Ueyama 2b53b4bea6 Attempt to fix ubsan.
Previously, we cast a pointer to Elf{32,64}_Chdr like this

  auto *Hdr = reinterpret_cast<const ELF64_Chdr>(Ptr);

and read from its members like this

  read32(&Hdr->ch_size);

I was thinking that this does not violate alignment requirement,
since &Hdr->ch_size doesn't really access memory, but seems like
it is a violation in terms of C++ spec (?)

In this patch, I use a different struct that allows unaligned access.

llvm-svn: 344083
2018-10-09 21:41:53 +00:00
Rui Ueyama e3ccd28660 Calculate an offset only once. NFC.
llvm-svn: 344076
2018-10-09 20:29:24 +00:00