Commit Graph

522 Commits

Author SHA1 Message Date
Peter Collingbourne d6924d7474 Reland r315114, "ELF: Export preempted symbols even if there is a dynamic list." which was reverted in r315116.
I hadn't synced past the change that changed the default hash style
to --hash-style=both, so my test had the symbols in the wrong order.

llvm-svn: 315119
2017-10-06 22:09:03 +00:00
Peter Collingbourne accab5908d Revert r315114, "ELF: Export preempted symbols even if there is a dynamic list."
For some reason the symbols get emitted in the wrong order on one of the
buildbots: http://bb9.pgr.jp/#builders/15/builds/180

llvm-svn: 315116
2017-10-06 21:48:39 +00:00
Peter Collingbourne 5a8928c605 ELF: Export preempted symbols even if there is a dynamic list.
Dynamic lists in an executable are additive, not restrictive, so we
must continue to export preempted symbols even with a dynamic list.

This fixes sanitizer interception of libc symbols (and should also fix
symbol preemption by users of sanitizers).

Differential Revision: https://reviews.llvm.org/D38647

llvm-svn: 315114
2017-10-06 21:33:59 +00:00
George Rimar d46753e421 [ELF] - Do --hash-style=both by default.
Its PR34712,

GNU linkers recently changed default values to "both" of "sysv".
Patch do the same for all targets except MIPS, where .gnu.hash
section is not yet supported.

Code suggested by Rui Ueyama.

Differential revision: https://reviews.llvm.org/D38407

llvm-svn: 315051
2017-10-06 09:37:44 +00:00
Rui Ueyama 945cd64471 Wait for all threads to terminate before exitting.
I think it is not defined what would happen to detached threads
when the main thread tries to exit. That means it was not guaranteed
that unlinkAsync correctly removes a temporary file. It was also
reported that this unlinkAsync caused a crash on Windows.

This patch adds a few new functions so that the main thread always
waits for non-main threads before exitting.

I don't actually like the new two functions, runBackground and
waitForBackgroundThreads, because it looks like it is a bit
overdesigned. After all, what we are doing with these functions
is to just remove a file.

An alternative would be to do fork(2) and make the child process
remove a file asynchronously. However, it has its own problems.
Correctly forking and reclaiming a resource using waitpid(2) is not
doable unless we know our process-wide settings (such as signal mask),
but we can't make any assumption on it when lld is embedded to other
process. So I chose to stick with threads instead of multi-processes.

Differential Revision: https://reviews.llvm.org/D38571

llvm-svn: 315033
2017-10-05 23:01:11 +00:00
Rui Ueyama 7d1f5fd840 Call exitLld() from elf::link.
We used to call exitLld() from a leaf function, Writer::run(), because
we had objects on the stack whose dtors are expensive. Now we no longer
have such objects on the stack, so there's no reason to exist from the
leaf function.

llvm-svn: 314869
2017-10-04 00:50:11 +00:00
Rui Ueyama a215e7cbe8 Move fetchIfLazy up so that the following comment makes sense.
We have this comment in LinkerDriver::link

  After this, no new names except a few linker-synthesized ones
  will be added to the symbol table.

but that was not true because new symbols could be added by processing
the -u option.

llvm-svn: 314842
2017-10-03 20:45:09 +00:00
Rui Ueyama fa105f8deb Inline a small function.
llvm-svn: 314841
2017-10-03 20:44:54 +00:00
Igor Kudrin fb7f8befec [ELF] Avoid promoting an undefined weak entry symbol to global.
Without this patch, lld emits "error: undefined symbol: _start"
if it encountered only weak references to that symbol.

llvm-svn: 314790
2017-10-03 12:23:46 +00:00
Rui Ueyama 3f851704c1 Move new lld's code to Common subdirectory.
New lld's files are spread under lib subdirectory, and it isn't easy
to find which files are actually maintained. This patch moves maintained
files to Common subdirectory.

Differential Revision: https://reviews.llvm.org/D37645

llvm-svn: 314719
2017-10-02 21:00:41 +00:00
Simon Atanasyan 649e4d328f [MIPS] Fix PLT entries generation in case of linking regular and microMIPS code
Currently LLD calls the `isMicroMips` routine to determine type of PLT entries
needs to be generated: regular or microMIPS. This routine checks ELF
header flags in the `FirstObj` to retrieve type of linked object files.
So if the first file does not contain microMIPS code, LLD will generate
PLT entries with regular (non-microMIPS) code only.

Ideally, if a PLT entry is referenced by microMIPS code only this entry
should contain microMIPS code, if a PLT entry is referenced by regular
code this entry should contain regular code. In a "mixed" case the PLT
entry can be either microMIPS or regular, but each "cross-mode-call" has
additional cost.

It's rather difficult to implement this ideal solution. But we can
assume that if there is an input object file with microMIPS code, the
most part of the code is microMIPS too. So we need to deduce type of PLT
entries based on finally calculated ELF header flags and do not check
only the first input object file.

This change implements this.
  - The `getMipsEFlags` renamed to the `calcMipsEFlags`. The function
    called from the `LinkerDriver::link`. Result is stored in
    the Configuration::MipsEFlags field.
  - The `isMicroMips` and `isMipsR6` routines access the `MipsEFlags`
    field to get and check calculated ELF flags.
  - New types of PLT records created when necessary.

Differential revision: https://reviews.llvm.org/D37747

llvm-svn: 314675
2017-10-02 14:56:41 +00:00
Ben Dunbobbin 73eabf23a4 [ELF] Simpler scheme for handling common symbols
Convert all common symbols to regular symbols after scan.
This means that the downstream code does not to handle common symbols as a special case.

Differential Revision: https://reviews.llvm.org/D38137

llvm-svn: 314495
2017-09-29 09:08:26 +00:00
Evgeny Mankov 31fef4d3f0 [ELF][fix] Using statically linked lld leads to segmentation fault on linking ELF
[Synopsys]
Using function elf::link(...) leads to segmentation fault on its second call. First call finishes correctly.
[Solution]
Clear the rest of globals.

Reviewed by: George Rimar and Rui Ueyama

Differential Revision: http://reviews.llvm.org/D38131

llvm-svn: 314108
2017-09-25 14:42:15 +00:00
Rafael Espindola 9e50291065 Include thin --whole-archive members in --reproduce.
We were only including the thin archive members used via a lazy symbol
before.

llvm-svn: 313832
2017-09-20 22:59:50 +00:00
George Rimar 696a7f9ac6 [ELF] - Introduce std::vector<InputFile *> global arrays.
This patch removes lot of static Instances arrays from different input file 
classes and introduces global arrays for access instead. Similar to arrays we
have for InputSections/OutputSectionCommands.

It allows to iterate over input files in a non-templated code.

Differential revision: https://reviews.llvm.org/D35987

llvm-svn: 313619
2017-09-19 09:20:54 +00:00
Rafael Espindola e05e2f8b34 Keep some relocations with undefined weak symbols.
This fixes pr34301.

As the bug points out, we want to keep some relocations with undefined
weak symbols. This means that we cannot always claim that these
symbols are not preemptible as we do now.

Unfortunately, we cannot also just always claim that they are
preemptible. Doing so would, for example, cause us to try to create a
plt entry when we don't even have a dynamic symbol table.

What almost works is to say that weak undefined symbols are
preemptible if and only if we have a dynamic symbol table. Almost
because we don't want to fail the build trying to create a copy
relocation to a weak undefined.

llvm-svn: 313372
2017-09-15 18:05:02 +00:00
Martell Malone 894dbbe8eb LLD: Introduce a GNU LD style driver for COFF
When building COFF programs many targets such as mingw prefer
to have a gnu ld frontend. Rather then having a fully fledged
standalone driver we wrap a shim around the LINK driver.

Extra tests were provided by mstorsjo

Reviewers: mstorsjo, ruiu

Differential Revision: https://reviews.llvm.org/D33880

llvm-svn: 312926
2017-09-11 17:02:59 +00:00
Rui Ueyama e2f52eb22f Add -no-gdb-index which negates -gdb-index option.
llvm-svn: 312753
2017-09-07 22:40:54 +00:00
Rui Ueyama 38eab87671 Add -no-eh-frame-hdr which negates -eh-frame-hdr.
Note that ld.bfd and ld.gold have the option.

llvm-svn: 312010
2017-08-29 16:53:24 +00:00
Rui Ueyama 00cf731ecd Make empty arguments visible in error messages.
Before this patch, lld printed out something like

  error: -O: number expected, but got

After this patch, it prints out the same error message like this:

  error: -O: number expected, but got ''

Fixes https://bugs.llvm.org/show_bug.cgi?id=34311

llvm-svn: 311681
2017-08-24 18:34:32 +00:00
George Rimar 51d193f8b3 [ELF] - Fix for "Bug 34238 - LTO is optimizing away symbols referenced from linker scripts"
Code suggested by Rui Ueyama in PR34238 comments.

Previously LTO optimized away symbols referenced from linker script
because did not see that them are used from regular objects.

Patch adds such symbols as undefined earlier, before running LTO,
what sets IsUsedInRegularObj for them and fixes the issue.

Differential revision: https://reviews.llvm.org/D37009

llvm-svn: 311534
2017-08-23 08:37:22 +00:00
Davide Italiano aa33e74f4b [ELF/LTO] -function-sections/-data-sections are exact options.
Also add a test. This fixes r310995 and PR34200.

llvm-svn: 310998
2017-08-16 08:21:04 +00:00
George Rimar d6d24ac437 [ELF] - Ignore -plugin-opt=-function-sections/-plugin-opt=-data-sections. NFC.
Clang passes this options to linker. We should ignore them,
anyways they are always enabled by default atm.

Fixes https://bugs.llvm.org/show_bug.cgi?id=34200.

llvm-svn: 310995
2017-08-16 07:25:09 +00:00
Rui Ueyama a13897245c Add a comment and remove a TODO.
A TODO is not a todo unless we really have to do it, but
they are not required at the moment.

llvm-svn: 310864
2017-08-14 17:48:30 +00:00
George Rimar 8bb437c98f [ELF] - Ignore --plugin-opt=mcpu= and --plugin-opt=thinlto.
Attemp to fix BB.

Previously we ignored all --plugin-opt options, 
but now (after r310826) error out on non implemented ones.
This caused BB to fail:

http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux/builds/3405/steps/check-cfi-and-supported%20in%20gcc%20build/logs/stdio

llvm-svn: 310835
2017-08-14 12:36:14 +00:00
George Rimar cb38bf526b [ELF] - LTO: Try to be option compatible with the gold plugin.
This is relative to PR30720.

Previously we ignored all --plugin-opt arguments.
Patch adds support for them.

Patch does not add any new LTO options,
and just implements mapping from --plugin-opt to existent ones.

Differential revision: https://reviews.llvm.org/D36227

llvm-svn: 310826
2017-08-14 10:17:30 +00:00
Rui Ueyama be7e001369 Add `-z muldefs` option.
llvm-svn: 310757
2017-08-11 20:49:48 +00:00
Rui Ueyama ae704a5472 Add --icf=none option.
--icf=none negates --icf=all.

llvm-svn: 310526
2017-08-09 21:32:38 +00:00
Rafael Espindola 3a8e4d98f8 Use more consistent names
Reviewing another change I noticed that we use "getSymbols" to mean
different things in different files. Depending on the file it can
return

ArrayRef<StringRef>
ArrayRef<SymbolBody*>
ArrayRef<Symbol*>
ArrayRef<Elf_Sym>

With this change it always returns an ArrayRef<SymbolBody*>. The other
functions are renamed getELFsyms() and getSymbolNames().

Note that we cannot return ArrayRef<Symbol*> instead of
ArreyRef<SymbolBody*> because local symbols have a SymbolBody but not
a Symbol.

llvm-svn: 309840
2017-08-02 17:35:18 +00:00
Rui Ueyama 709fb2bb10 Rename ObjectFile -> ObjFile.
Rename it because it was too easy to conflict with llvm::object::ObjectFile
which broke buildbots several times.

llvm-svn: 309199
2017-07-26 22:13:32 +00:00
Rafael Espindola 244ef98161 Detemplate SymbolTable.
NFC, just makes it easier to access from non templated code.

llvm-svn: 309152
2017-07-26 18:42:48 +00:00
George Rimar 84941ef158 [ELF] - Change way how we handle --noinhibit-exec
Previously we handled this option implicitly, only
for infering unresolved symbols handling policy.

ld man says: "--noinhibit-exec Retain the executable
output file whenever it is still usable",
and we may want to handle other cases too.

Differential revision: https://reviews.llvm.org/D35793

llvm-svn: 309091
2017-07-26 09:46:59 +00:00
George Rimar 4f37d57547 [ELF] - Introduce multiclass Eq helper for Options.td
Eq helper allows to define `XXX` and `XXX=` options forms easily.
Patch adds testcases for few aliases.

Differential revision: https://reviews.llvm.org/D35619

llvm-svn: 308752
2017-07-21 16:27:26 +00:00
Rui Ueyama 875ae82b0b Add the --chroot option for --reproduce.
Summary:
If the linker is invoked with `--chroot /foo` and `/bar/baz.o`, it
tries to read the file from `/foo/bar/baz.o`. This feature is useful
when you are dealing with files created by the --reproduce option.

Reviewers: grimar

Subscribers: llvm-commits, emaste

Differential Revision: https://reviews.llvm.org/D35517

llvm-svn: 308646
2017-07-20 18:17:55 +00:00
Rui Ueyama 38b0f4a1f2 Handle option aliases in a better way.
In this way, we don't need to know which options have aliases.

llvm-svn: 308519
2017-07-19 20:30:04 +00:00
George Rimar f525c928cf [ELF] - Implement filter library support (-F / --filter)
This is PR33766.

-F name
--filter=name
When creating an ELF shared object, set the internal DT_FILTER field to the specified name. This tells the dynamic linker that the symbol table of the shared object which is being created should be used as a filter on the symbol table of the shared object name.

If you later link a program against this filter object, then, when you run the program, the dynamic linker will see the DT_FILTER field. The dynamic linker will resolve symbols according to the symbol table of the filter object as usual, but it will actually link to the definitions found in the shared object name. Thus the filter object can be used to select a subset of the symbols provided by the object name.
(https://linux.die.net/man/1/ld).

Shared Objects as Filters:
https://docs.oracle.com/cd/E19683-01/817-3677/chapter4-31738/index.html

Differential revision: https://reviews.llvm.org/D35352

llvm-svn: 308167
2017-07-17 09:43:18 +00:00
Zachary Turner 6708e0b45e [lld/pdb] Add some basic linker module symbols.
Differential Revision: https://reviews.llvm.org/D35152

llvm-svn: 307590
2017-07-10 21:01:37 +00:00
Rui Ueyama d1f8b8162b Implement the --exclude-libs option.
The --exclude-libs option is not a popular option, but at least some
programs in Android depend on it, so it's worth to support it.

Differential Revision: https://reviews.llvm.org/D34422

llvm-svn: 305920
2017-06-21 15:36:24 +00:00
Rui Ueyama d2ccdbfa61 Remove redundant namespace specifier.
llvm-svn: 305877
2017-06-21 03:05:08 +00:00
James Henderson 38e67e8212 [ELF] Emit only one error if -z max-page-size without value
In r305364, Rui changed the mechanism that parses -z option values slightly.
This caused a bug, as demonstrated by this test, which now fails:

---
# REQUIRES: x86
# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
# RUN: ld.lld %t.o -o %t -z max-page-size

.global _start
_start:
  nop
---

Before, the link succeeded and set the max-page-size to the target default.

After we get the following two error messages:
"invalid max-page-size: "
"max-page-size: value isn't a power of 2"

The latter error is because an uninitialised variable ends up being passed back
to getMaxPageSize).

This change ensures we only get the first error.

Reviewers: ruiu

Differential Revision: https://reviews.llvm.org/D34234

llvm-svn: 305679
2017-06-19 11:05:15 +00:00
Rui Ueyama e145bc22fd Do not use make<> to allocate TargetInfo. NFC.
llvm-svn: 305577
2017-06-16 20:15:03 +00:00
Eugene Leviant ad270ec314 [ELF] Add armelf emulation mode
Differential revision: https://reviews.llvm.org/D34140

llvm-svn: 305375
2017-06-14 08:25:38 +00:00
Yuka Takahashi 1f1378dcbc Use getLastArgValue instead of getString
Summary: I found that getString defined in the LLD's Driver.cpp is
exactly the same as Arg::getLastArgValue defined in
llvm/Option/ArgLIst.h. This patch removes that local function and use
the function that the Arg class provides.

Reviewers: ruiu

Subscribers: emaste, llvm-commits

Differential Revision: https://reviews.llvm.org/D34196

llvm-svn: 305374
2017-06-14 08:01:26 +00:00
Rui Ueyama d3a4a3e3e4 Use StringRef::split instead of StringRef::find and StringRef::substr.
Summary: Pointed out by Yuka Takahashi.

Differential Revision: https://reviews.llvm.org/D34192

llvm-svn: 305364
2017-06-14 04:02:40 +00:00
Peter Collingbourne dc7936eced ELF: Move section merging before ICF. NFCI.
Differential Revision: https://reviews.llvm.org/D34093

llvm-svn: 305176
2017-06-12 00:00:51 +00:00
George Rimar 1840901a2f [ELF] - Allow producing -r output if only empty archive is given.
This is used by linux kernel build system.

(https://www.kernel.org/doc/Documentation/kbuild/makefiles.txt "3.2 Built-in object goals")

It has for example next configuration for linking built-in.o files:
drivers-y	:= $(patsubst %/, %/built-in.o, $(drivers-y))
drivers-$(CONFIG_PCI)		+= arch/ia64/pci/
...
drivers-$(CONFIG_OPROFILE)	+= arch/ia64/oprofile/

Im most simple case all CONFIG_* options are off. That means linker is called with empty input archive, 
emulation option and no inputs and expected to generate some relocatable output. 
ld.bfd is able to do that, we dont.

Patch allows to support this case.

Differential revision: https://reviews.llvm.org/D33937

llvm-svn: 305069
2017-06-09 12:26:57 +00:00
Dmitry Mikulin db3b87b2c0 Symbols re-defined with -wrap and -defsym need to be excluded from inter-
procedural optimizations to prevent dropping symbols and allow the linker
to process re-directs.

PR33145: --wrap doesn't work with lto.
Differential Revision: https://reviews.llvm.org/D33621

llvm-svn: 304719
2017-06-05 16:24:25 +00:00
Petr Hosek ffa786f465 [lld][ELF]Add option to make .dynamic read only
The .dynamic section of an ELF almost doesn't need to be written to with
the exception of the DT_DEBUG entry. For several reasons having a read
only .dynamic section would be useful. This change adds the -z keyword
"rodynamic" which forces .dynamic to be read-only. In this case DT_DEBUG
will not be emited.

Patch by Jake Ehrlich

Differential Revision: https://reviews.llvm.org/D33251

llvm-svn: 304024
2017-05-26 19:12:38 +00:00
Peter Collingbourne 968fe93803 ELF: The later of --build-id and --build-id= wins.
If the compiler driver passes --build-id and the user uses -Wl to
pass --build-id= then the user's flag should take precedence.

Differential Revision: https://reviews.llvm.org/D33461

llvm-svn: 303689
2017-05-23 21:16:48 +00:00
George Rimar ab94768cc1 [ELF] - Use llvm::to_integer() instead of StringRef::getAsInteger().
Switch to llvm::to_integer() everywhere in LLD instead of 
StringRef::getAsInteger() because API of latter is confusing. 
It returns true on error and false otherwise what makes reading 
the code incomfortable.

Differential revision: https://reviews.llvm.org/D33187

llvm-svn: 303149
2017-05-16 08:19:25 +00:00