Commit Graph

216 Commits

Author SHA1 Message Date
Rui Ueyama 33b3f21168 Rename GroupEntryType -> uint32_X.
GroupEntryType was a 32-bit integral type but that was not obvious
from its name.

llvm-svn: 256971
2016-01-06 20:30:02 +00:00
Rui Ueyama 52d3b67c1d Rename Comdats -> ComdatGroups.
I usually prefer short names, but in this case the new descriptive
name should improve readability a bit.

llvm-svn: 256899
2016-01-06 02:06:33 +00:00
Rui Ueyama 7c713319b9 Rename SharedFile::parse -> SharedFile::parseRest.
Unlike ObjectFile or ArchiveFile, SharedFile had two parse functions,
parseSoName() and parse(). parse must have been called after parseSoName,
but that requirement was not obvious from their names. (So it looked
like you could call parse() on a shared object file right away.)

This patch rename parseRest. It is now obvious that there's no single
parse function for the shared object file.

llvm-svn: 256898
2016-01-06 01:56:36 +00:00
Rui Ueyama e69ab10301 Remove redundant this->.
llvm-svn: 256894
2016-01-06 01:14:11 +00:00
Rui Ueyama 9b09369b3d Simplify --whole-archive handling.
Previously, we handle archive files with --whole-archive this way:
create instances of ArchiveFile, call getMembers to obtain memory
buffers of archive members, and create ObjectFiles for the members.
We didn't call anything except getMembers if --whole-archive was
specified.

I noticed that we didn't actually have to create ArchiveFile instaces
at all for that case. All we need is to get a list of memory buffers
for members, which can be done by a non-member function.

This patch removes getMembers member function from ArchiveFile.
Also removed unnecessary code for memory management.

llvm-svn: 256893
2016-01-06 00:51:35 +00:00
Rui Ueyama 533c03078b Do not use templates to instantiate {Object,Shared}Files.
createELFFile looked complex because of its use of template,
so I want to keep it private within this file.

llvm-svn: 256880
2016-01-06 00:09:43 +00:00
Simon Atanasyan 57830b60dc [ELF][MIPS] Implement R_MIPS_GPREL16/R_MIPS_GPREL32 relocations
The R_MIPS_GPREL16 / R_MIPS_GPREL32 relocations use the following
expressions for calculations:
```
local symbol:  S + A + GP0 - GP
global symbol: S + A - GP

GP  - Represents the final gp value, i.e. _gp symbol
GP0 - Represents the gp value used to create the relocatable object
```
The GP0 value is taken from the .reginfo data section defined by an object
file. To implement that I keep a reference to `MipsReginfoInputSection`
in the `ObjectFile` class. This reference is used by the
`ObjectFile::getMipsGp0` method to return the GP0 value.

Differential Revision: http://reviews.llvm.org/D15760

llvm-svn: 256416
2015-12-25 13:02:13 +00:00
Rui Ueyama 3f11c8c97e Split functions and add comments. NFC.
llvm-svn: 256369
2015-12-24 08:41:12 +00:00
Rafael Espindola 21f7bd4ba1 Simplify memory management.
We no longer need an explicit delete or a polymorphic destructor.

llvm-svn: 256333
2015-12-23 14:35:51 +00:00
Rafael Espindola ce7d39d5e1 Fix the last leak asan found in test/ELF.
llvm-svn: 256316
2015-12-23 03:40:17 +00:00
Rafael Espindola 7300afa36a Fix another asan detected leak.
llvm-svn: 256311
2015-12-23 01:18:40 +00:00
Rafael Espindola 5f2c46d62e Fix two asan found bugs:
We were leaking InputFile subclasses data.
UndefinedElf was missing a classof.

llvm-svn: 256309
2015-12-23 01:06:39 +00:00
Rui Ueyama 2022e81af0 Make a function out-of-line.
There's no need to write it in a .h file.

llvm-svn: 253633
2015-11-20 02:10:52 +00:00
Rafael Espindola 115f0f365d Two small fixes to copy relocation processing.
* We can determine the alignment requirement.
* We have to update the bss alignment with it.

llvm-svn: 251914
2015-11-03 14:13:40 +00:00
Rafael Espindola de212f1589 Delete dead getter.
llvm-svn: 251908
2015-11-03 13:36:38 +00:00
Rui Ueyama c4aaed9255 ELF2: Implement --gc-sections.
Section garbage collection is a feature to remove unused sections
from outputs. Unused sections are sections that cannot be reachable
from known GC-root symbols or sections. Naturally the feature is
implemented as a mark-sweep garbage collector.

In this patch, I added Live bit to InputSectionBase. If and only
if Live bit is on, the section will be written to the output.
Starting from GC-root symbols or sections, a new function, markLive(),
visits all reachable sections and sets their Live bits. Writer then
ignores sections whose Live bit is off, so that such sections are
excluded from the output.

This change has small negative impact on performance if you use
the feature because making sections means more work. The time to
link Clang changes from 0.356s to 0.386s, or +8%.

It reduces Clang size from 57,764,984 bytes to 55,296,600 bytes.
That is 4.3% reduction.

http://reviews.llvm.org/D13950

llvm-svn: 251043
2015-10-22 18:49:53 +00:00
Rafael Espindola c159c967f6 Add support for merging the contents of SHF_MERGE sections.
For now SHF_STRINGS are not supported.

llvm-svn: 250737
2015-10-19 21:00:02 +00:00
Rafael Espindola 4cda58168a Add a ObjectFile<ELFT>::getSection helper and simplify. NFC.
llvm-svn: 250519
2015-10-16 15:29:48 +00:00
Rui Ueyama f8432d97f3 ELF2: Fix BSD's __progname symbol issue.
BSD's DSO files have undefined symbol "__progname" which is defined
in crt1.o. On that system, both user programs and system shared
libraries depend on each other.

In general, we need to put symbols defined by user programs which are
referenced by shared libraries to user program's .dynsym.

http://reviews.llvm.org/D13637

llvm-svn: 250176
2015-10-13 16:34:14 +00:00
Rafael Espindola 2a4b27111d Remove the EKind member variable.
Now that the base class is templated, it is redundant with the type.

llvm-svn: 250139
2015-10-13 01:17:02 +00:00
Rui Ueyama c4b6506521 ELF2: Move createELFFile() from .h to .cpp.
llvm-svn: 250051
2015-10-12 15:31:09 +00:00
Rui Ueyama 4702b86176 Fix indentation.
llvm-svn: 250047
2015-10-12 15:15:45 +00:00
Rafael Espindola fb677dfd73 Make getStaticELFKind a member function now that we can.
llvm-svn: 250031
2015-10-12 12:14:30 +00:00
Rafael Espindola 9b278a1695 This doesn't need to be virtual anymore.
llvm-svn: 250028
2015-10-12 11:26:55 +00:00
Rafael Espindola dfce5a25cb Simplify the InputFile type hierarchy by removing unnecessary middle classses.
llvm-svn: 250006
2015-10-12 02:22:58 +00:00
Rafael Espindola af70764aa1 Simplify the InputFile type hierarchy.
Now that the SymbolTable is templated, we don't need the ELFData class or
multiple inheritance.

llvm-svn: 250005
2015-10-12 01:55:32 +00:00
Rui Ueyama 35da9b6e1c ELF2: Implement --as-needed.
This patch adds AsNeeded and IsUsed bool fields to SharedFile. AsNeeded bit
is set if the DSO is enclosed with --as-needed and --no-as-needed. IsUsed
bit is off by default. When we adds a symbol to the symbol table for dynamic
linking, we set its SharedFile's IsUsed bit.

If AsNeeded is set but IsUsed is not set, we don't want to write that
file's SO name to DT_NEEDED field.

http://reviews.llvm.org/D13579

llvm-svn: 249998
2015-10-11 20:59:12 +00:00
Rafael Espindola 9afbac479f Handle a crash in conflict detection with archive members.
llvm-svn: 249996
2015-10-11 20:19:20 +00:00
Rafael Espindola 525914defd Detect incompatible files when one of them comes from an archive.
llvm-svn: 249968
2015-10-11 03:36:49 +00:00
Rafael Espindola 444576d4c4 Add support for comdats.
The implementation is a direct translation to c++ of the rules in the ELF spec.

llvm-svn: 249881
2015-10-09 19:25:07 +00:00
Rui Ueyama e66e001c90 ELF2: Use the same name as COFF.
llvm-svn: 249635
2015-10-07 23:20:23 +00:00
Denis Protivensky 1ef7b3ff55 [ELF2] Handle -m option
Parse and apply emulation given with -m option.
Check input files to match ELF type and machine architecture provided with -m.

Differential Revision: http://reviews.llvm.org/D13055

llvm-svn: 249529
2015-10-07 09:13:03 +00:00
Rafael Espindola 6a3b5ded8a Don't include shared libraries multiple times.
llvm-svn: 249061
2015-10-01 19:52:48 +00:00
Igor Kudrin 2696bbeb93 [ELF2] Add --[no-]whole-archive command line switches
Summary:
If --whole-archive is used, all symbols from the following archives are added to the output. --no-whole-archive restores default behavior. These switches can be used multiple times.

NB. We have to keep an ArchiveFile instance within SymbolTable even if --whole-archive mode is active since it can be a thin archive which contains just names of external files. In that case actual memory buffers for the archive members will be stored within the File member of ArchiveFile class.

Reviewers: rafael, ruiu

Subscribers: grimar, llvm-commits

Projects: #lld

Differential Revision: http://reviews.llvm.org/D13286

llvm-svn: 249045
2015-10-01 18:02:21 +00:00
Rafael Espindola c8b158155c Copy DT_SONAME to DT_NEEDED.
If a shared library has a DT_SONAME entry, that is what should be included
in the DT_NEEDED of a program using it.

We don't implement -soname yet, so check in a .so for now.

llvm-svn: 249025
2015-10-01 15:47:50 +00:00
Rui Ueyama 983ed2b749 ELF2: Define Driver::addFile() as a one-stop place to open a file.
Opening a file and dispatching to readLinkerScript() or createFile()
is a common operation. We want to use that at least from Driver and
from LinkerScript. In COFF, we had the same problem. This patch
resolves the problem in the same way as we did for COFF.

Now, if you have a path that you want to open, just call
Driver->addFile(StringRef). That function opens the file and handles
that as if that were given by command line. This function is the
only place we call identify_magic().

llvm-svn: 249023
2015-10-01 15:23:09 +00:00
Rui Ueyama f5c4aca98f ELF2: Add basic linker script support.
This linker script parser and evaluator is powerful enough to read
Linux's libc.so, which is (despite its name) a linker script that
contains OUTPUT_FORMAT, GROUP and AS_NEEDED directives.

The parser implemented in this patch is a recursive-descendent one.
It does *not* construct an AST but consumes directives in place and
sets the results to Symtab object, like what Driver is doing.
This should be very fast since less objects are allocated, and
this is also more readable.

http://reviews.llvm.org/D13232

llvm-svn: 248918
2015-09-30 17:06:09 +00:00
Rui Ueyama 294b136db4 Remove `explicit` from constructors that take more than one parameter.
llvm-svn: 248873
2015-09-30 02:06:17 +00:00
Rui Ueyama c5e22d906b ELF2: Include file names in error messages.
llvm-svn: 248724
2015-09-28 18:20:41 +00:00
Davide Italiano aa7c533ec3 [ELF2] Fix binaries so they actually run on FreeBSD.
Since FreeBSD 4.1, the kernel expects binaries to be marked with
ELFOSABI_FREEBSD in the ELF header to exec() them. LLD unconditionally 
sets OSABI to ELF_OSABINONE, and everything linked with it won't run 
on FreeBSD (unless explicitly rebranded).

Example:
% ./aarch64-hello
ELF binary type "0" not known.
zsh: exec format error: ./aarch64-hello

FreeBSD could be modified to accept ELF_OSABINONE, but that would break all
existing binaries, so the kernel needs to support both ABINONE and ABIFREEBSD.
I plan to push this change in FreeBSD one day, which, unfortunately, is 
not today. This code patches lld so it sets the header field correctly.

For completeness, the rationale of this change is explained in the FreeBSD 
commit message, and it's apparently to pleasee binutils maintainers at the time.
https://svnweb.freebsd.org/base?view=revision&revision=59342

Differential Revision:	 http://reviews.llvm.org/D13140

llvm-svn: 248554
2015-09-25 01:59:13 +00:00
Rafael Espindola e1901cc33d Simplify memory management by having ELFData contain a ELFObj.
llvm-svn: 248502
2015-09-24 15:11:50 +00:00
Rafael Espindola 503fe9408d Expose ELFFileBase::getEMachine. NFC.
I will use it in a followup patch.

llvm-svn: 248287
2015-09-22 16:53:55 +00:00
Rafael Espindola 7167585c94 Remove the Chunk terminology from ELF.
llvm-svn: 248229
2015-09-22 00:16:19 +00:00
Rafael Espindola 9d06ab6ded Rename Chunks.(h|cpp) to InputSection.(h|cpp). NFC.
llvm-svn: 248226
2015-09-22 00:01:39 +00:00
Rafael Espindola 53d5cea648 Rename SectionChunk to InputSection.
This is more consistent with OutputSection. This is also part of removing
the "Chunk" term from the ELF linker, since we just have input/output sections
and program headers.

llvm-svn: 248183
2015-09-21 17:47:00 +00:00
Davide Italiano f7892a1f3a [ELF2] Constify member functions.
llvm-svn: 248019
2015-09-18 18:28:08 +00:00
Rafael Espindola 5c2310c30c Start adding support for creating the GOT.
With this a program can call into a shared library with

  jmp *foo@GOTPCREL(%rip)

llvm-svn: 247992
2015-09-18 14:40:19 +00:00
Davide Italiano b5b47b432b [ELF2] Fill up local symbols fields correctly.
Differential Revision:	http://reviews.llvm.org/D12944

llvm-svn: 247960
2015-09-18 01:08:17 +00:00
Davide Italiano 6d328d3841 [ELF2] Initial support for local symbols.
Symbol table is now populated correctly, but some fields are missing,
they'll be added in the future. This patch also adds --discard-all
flag, which was the default behavior until now.

Differential Revision:   http://reviews.llvm.org/D12874

llvm-svn: 247849
2015-09-16 20:45:57 +00:00
Rafael Espindola 19e3889dba Start creating dynamic relocations.
For now we don't create got/plt and only Elf_Rela is supported.

llvm-svn: 247811
2015-09-16 15:54:15 +00:00
Rafael Espindola 18173d420e Start adding support for symbols in shared libraries.
llvm-svn: 247019
2015-09-08 15:50:05 +00:00
Michael J. Spencer 1b348a68e5 [elf2] Add basic archive file support.
llvm-svn: 246886
2015-09-04 22:28:10 +00:00
Rafael Espindola f98d6d84cd Start adding support for shared libraries.
This just adds the types and enough support to detect incompatibilities among
shared libraries and object files.

llvm-svn: 246797
2015-09-03 20:03:54 +00:00
Rafael Espindola 8788e1a630 Make getSymbols non-virtual. NFC.
llvm-svn: 246731
2015-09-02 23:01:37 +00:00
Rafael Espindola 905ad3442d Split out the ELF kind from the InputFile Kind.
There were at least two issues with having them together:
* For compatibility checks, we only want to look at the ELF kind.
* Adding support for shared libraries should introduce one InputFile kind,
  not 4.

llvm-svn: 246707
2015-09-02 20:43:43 +00:00
Rafael Espindola f2f41a9f97 Fix the gcc build:
InputFiles.h:98:53: error: invalid use of incomplete type ‘class lld::elf2::SymbolBody’
     return SymbolBodies[SymbolIndex - FirstNonLocal]->getReplacement();

llvm-svn: 246262
2015-08-28 02:40:04 +00:00
Michael J. Spencer 67bc8d6b3f [elf2] Add basic relocation support for x86-64.
This currently doesn't handle local symbols.

Differential Revision: http://reviews.llvm.org/D11612

llvm-svn: 246234
2015-08-27 23:15:56 +00:00
Rafael Espindola 2034822981 Add support for reading files with more than 0xff00 sections.
llvm-svn: 245880
2015-08-24 21:43:25 +00:00
Rafael Espindola beee25e484 Make these headers as being c++.
llvm-svn: 245050
2015-08-14 14:12:54 +00:00
Rafael Espindola d8340dae0c Don't depend on getDotSymtabSec. It is going away.
llvm-svn: 244451
2015-08-10 15:12:17 +00:00
Rafael Espindola e7a00e326a For now we only have on Chunk type. Simplify.
The others we have in sight are
* common symbols.
* entries in SHF_MERGE sections.

They will have a substantially different treatment. It is not clear if it is
worth it putting them all in a single list just to dispatch based on the kind on
the other side.

I hope to implement common symbols soon, and then we will be in a position
to have a concrete discussion. For now this is simpler for the the implemented
features.

llvm-svn: 244042
2015-08-05 13:55:34 +00:00
Rafael Espindola 3c9cb4b3d3 lld elf2: Diagnose trying to mix incompatible files.
This is also a step in instantiating the writer with the correct template
argument.

llvm-svn: 244035
2015-08-05 12:03:34 +00:00
Rafael Espindola 2ffdd4d0e5 The SymbolTable doesn't need to be a template.
It was already using just code that is common to all object files.

llvm-svn: 243985
2015-08-04 14:29:01 +00:00
Michael J. Spencer 84487f1174 [ELF2] Add a new ELF linker based on the new PE/COFF linker.
Differential Revision: http://reviews.llvm.org/D11188

llvm-svn: 243161
2015-07-24 21:03:07 +00:00
Michael J. Spencer bae540e945 Revert ELF port. Posting to mailing list.
llvm-svn: 242118
2015-07-14 04:49:48 +00:00
Michael J. Spencer 8a4145411f Initial ELF port.
This is a direct port of the new PE/COFF linker to ELF.

It can take a single object file and generate a valid executable that executes at the first byte in the text section.

llvm-svn: 242088
2015-07-13 23:48:06 +00:00