In the last patch for --trace-symbol, I introduced a new symbol type
PlaceholderKind and store it to SymVector storage. It made all code
that iterates over SymVector to recognize and skip PlaceholderKind
symbols. I found that that's annoying.
In this patch, I removed PlaceholderKind and stop storing them to SymVector.
Now the information whether a symbol is being watched by --trace-symbol
is stored to the Symtab hash table.
llvm-svn: 275747
SymVector contains all symbols, so we can iterate either Symtab or SymVector
to visit all symbols. Iterating over SymVector makes the next change for
--trace-symbol possible.
llvm-svn: 275746
--trace-symbol is a command line option to watch a symbol.
Previosly, we looked up a hash table for a new symbol if the
option is given. Any code that looks up a hash table for each
symbol is expensive because the linker handles a lot of symbols.
In our design, we look up a hash table strictly only once
for a symbol, so --trace-symbol was an exception.
This patch improves efficiency of the option by merging the
hash table into the symbol table.
Instead of looking up a separate hash table with a string,
this patch sets `Traced` flag to symbols specified by --trace-symbol.
So, if you insert a symbol and get a symbol with `Traced` flag on,
you know that you need to print out a log message for the symbol.
This is nearly zero cost.
llvm-svn: 275716
Versions can be assigned to symbols in two different ways.
One is the usual version scripts, and the other is special
symbol suffix '@'. If a symbol contains '@', the string after
that is considered to specify a version name.
Previously, we look for '@' for all symbols.
Anything that works on every symbol can be expensive because
the linker has to handle a lot of symbols. The search for '@'
was not an exception.
In this patch, I made two optimizations.
The first optimization is to handle '@' only when at least one
version is defined. If no versions are defined, no versions can
be assigned to any symbols, so it's waste of time to search for '@'.
The second optimization is to scan only suffixes of symbol names
instead of entire symbol names. Symbol names can be very long, but
symbol versions are usually short, so scanning entire symbol names
is waste of time, too.
There are some error cases which we no longer be able to detect
with this patch. I don't think it's a major drawback because they
are minor errors. Speed is more important.
This change improves LLD with debug info self-link time from
6.6993 seconds to 6.3426 seconds (or -5.3%).
Differential Revision: https://reviews.llvm.org/D22433
llvm-svn: 275711
Previously, each subclass of SymbolBody had a pointer to a source
file from which it was created. So, there was no single way to get
a source file for a symbol. We had getSourceFile<ELFT>(), but the
function was a bit inconvenient as it's a template.
This patch makes SymbolBody have a pointer to a source file.
If a symbol is not created from a file, the pointer has a nullptr.
llvm-svn: 275701
The identifier `Version` was used too often in the code to handle
symbol versions. The struct that contains version definitions is
named `Version`. Local variables for version ID are named `Version`.
Local varaible for version string are named `Version`.
This patch give them different names.
llvm-svn: 275673
Previously, Verdefs and Verdauxs are separated in the section.
The new layout is easier to write as we do not have to maintain
two pointers and can avoid passing a reference to a pointer.
llvm-svn: 275665
In a linker script, `.` is a special symbol indicating a counter.
Previously, we had two expression types, ExprKind and SymbolAssignmentKind
for `.` and all the other symbol names, respectively. But we could merge
them because the former is a special case of the latter.
llvm-svn: 275527
Previously, it checked for the EC parameter and set HasError
only when there was an error. But in most places we called
error only when error had occurred, so this behavior was confusing.
llvm-svn: 275517
Dispatching based on argv[0] seems to be more convenient for users
than dispatching based on -flavor option. Currently, when a user
invoke LLD as "lld", we recommend them pass -flavor option. This
patch changes the message so that we recommend use ld.lld, ld or
lld-link instead.
Differential Revision: http://reviews.llvm.org/D22321
llvm-svn: 275448
ELF spec says that alignment of 0 is equivalent to 1.
Previously, we arbitrary set to 0 or 1, but always setting to 1
makes our program simpler.
llvm-svn: 275374
r275301 made .got section be aligned on Target->GotEntrySize,
so GotEntrySize must have been initialized. We didn't initialize
it for AMDGPU.
llvm-svn: 275373
Patch by H.J Lu.
For x86-64 psABI, the entry size of .got and .got.plt sections is 8
bytes for both LP64 and ILP32. Add GotEntrySize and GotPltEntrySize
to ELF target instead of using size of ELFT::uint. Now we can generate
a simple working x32 executable.
Differential Revision: http://reviews.llvm.org/D22288
llvm-svn: 275301
Config members are named after corresponding command line options.
This patch renames VAStart ImageBase so that they are in line with
--image-base.
Differential Revision: http://reviews.llvm.org/D22277
llvm-svn: 275298
This is to follow the convention of naming the test after the name
of the option.
Differential Revision: http://reviews.llvm.org/D22276
llvm-svn: 275295
Minor cleanup.
Currently it looks wierd that having method addPredefinedSections()
we still add 2 sections outside it without real reasons.
Patch fixes that.
Differential revision: http://reviews.llvm.org/D19981
llvm-svn: 275269
Patch implements 'extern' version script tag.
Currently only values in quotes(") are supported.
Matching of externs is performed in the same pass as exact match of globals.
Differential revision: http://reviews.llvm.org/D21930
llvm-svn: 275257
lld currently relies on lib.exe in order to generate an empty import library.
The "empty" import library consists of 5 members:
- first linker member
- second linker member
- Import Descriptor
- NULL Import Descriptor
- NULl Thunk
The first two entries (first and second linker members) are string tables which
are never updated. Therefore, they may as well as not be present. A subsequent
change to add that is probably warranted. However, this does not prevent the
use of the linker.
The Import Descriptor is the content which is most important. It provides an
Import Name Table entry for the library (as specified by the LIBRARY directive
in the DEF file). Additionally, it contains undefined references to the NULL
Import Descriptor and the library NULL Thunk Data. This ensures that the linker
will pull in the subsequent objects from the import library for the link. The
Import Descriptor has a single symbol (__IMPORT_DESCRIPTOR_<Library>) which
contains 3 relocations, one to the INT (Import Name Table) entry, one to the ILT
(Import Lookup Table) entry, and one to the IAT (Import Address Table) entry.
The NULL Import Descriptor is the last import descriptor and terminates the
import descriptor array. It contains a single symbol
(__NULL_IMPORT_DESCRIPTOR).
The NULL Thunk contains a single symbol (\x7f<Library>_NULL_THUNK_DATA) and
provides the terminator for the ILT and IAT.
These files are currently constructed manually following the example of the
Short Import Library format. This is arguably less than ideal, and it may be
possible to use MCAssembler and feed it the fragments to construct the object.
The major difference between the LIB (LINK) generated objects and the ones
generated here is that they are all one section shorter (.debug$S) as they do
not contain the debug information and one symbol shorter (@comp.id) as they do
not contain the RICH signature.
Move the logic related to the librarian into a new source file (Librarian.cpp).
llvm-svn: 275242
Patch by H.J. Lu.
This patch adds -m elf32_x86_64 to lld. But it doesn't generate working
x32 binaries.
Differential Revision: http://reviews.llvm.org/D22268
llvm-svn: 275236
Patch by H.J. Lu.
As x86-64 psABI supports both LP64 and ILP32, this patch adds <ELFT>
template to X86_64TargetInfo.
Differential Revision: http://reviews.llvm.org/D22287
llvm-svn: 275235
Creating sections on linkerscript side requires some methods
that can be reused if are exported from writer.
Patch implements that change.
Differential revision: http://reviews.llvm.org/D20104
llvm-svn: 275162
Since linkerscript should create sections by itself
(if SECTIONS command is present),
then we might want to reuse the OutputSectionFactory (D19976 already do that now),
so this patch moves it out from writer cpp file for that purpose.
Differential revision: http://reviews.llvm.org/D19977
llvm-svn: 275161
That helps to avoid expressions like I + 2 in code
that assigns version number to symbols.
Change was suggested by Rui Ueyama.
Differential revision: http://reviews.llvm.org/D22086
llvm-svn: 275159
Only MipsThunk were using the function, and the way how it wrote
thunk contents was different from ARM thunks. This patch makes
them consistent.
llvm-svn: 274997
Although they are in the same .cpp file, the way they were written
were slightly different, so they looked more different than they were.
This patch makes their styles consistent.
llvm-svn: 274996
Symbol's dtors are not called because they are allocated using
BumpPtrAllocators. So, members of std::unique_ptr type are not
freed when symbols are deallocated.
This patch is to allocate Thunks using BumpPtrAllocators.
llvm-svn: 274896
The TinyPtrVector of const Thunk<ELFT>* in InputSections.h can cause
build failures on certain compiler/library combinations when Thunk<ELFT>
is not a complete type or is an abstract class. Fixed by making Thunk<ELFT>
non Abstract.
type or is an abstract class
llvm-svn: 274863
Generalise the Mips LA25 Thunk code and implement ARM and Thumb
interworking Thunks.
- Introduce a new module Thunks.cpp to store the Target Specific Thunk
implementations.
- DefinedRegular and Shared have a ThunkData field to record Thunk.
- A Target can have more than one type of Thunk.
- Support PC-relative calls to Thunks.
- Support Thunks to PLT entries.
- Existing Mips LA25 Thunk code integrated.
- Support for ARMv7A interworking Thunks.
Limitations:
- Only one Thunk per SymbolBody, this is sufficient for all currently
implemented Thunks.
- ARM thunks assume presence of V6T2 MOVT and MOVW instructions.
Differential revision: http://reviews.llvm.org/D21891
llvm-svn: 274836
When building executable usually version script is absent.
Before this patch error was shown in the case when
symbol name contained version and there was no script to match it.
Instead of error out patch allows
to create new version declaration in this case and use it.
gnu linkers do the same.
That is PR28359.
Differential revision: http://reviews.llvm.org/D21890
llvm-svn: 274828
Previously, it was not tested because the test was written in
a way that it passed on a platform that does not support
abi::__cxa_demangle. Now we restrict this test to Unix (by adding
"REQUIRES: shell") and assume that it always demangle symbols.
Thanks to Davide to find out the issue.
llvm-svn: 274808
Symbols.cpp contains functions to handle ELF symbols.
demangle() function is essentially a function to work on a
string rather than on an ELF symbol. So Strings.cpp is a
better place to put that function.
This change also make demangle to demangle symbols unconditionally.
Previously, it demangled symbols only when Config->Demangle is true.
llvm-svn: 274804
Previously we had incorrect logic here. Imagine we would have the next script:
LIBSAMPLE_1.0
{
global:
a_2;
local:
*;
};
LIBSAMPLE_2.0
{
global:
a*;
};
According to previous logic it would assign version 1 to a_2 and then
would try to reassign it to version 2 because of applying wildcard a*.
And show a warning about that.
Generally Ian Lance Tailor wrote about next rules that should be applied:
(http://www.airs.com/blog/archives/300)
Here are the current rules for gold:
"If there is an exact match for the mangled name, we use it. If there is more than one exact match, we give a warning, and we use the first tag in the script which matches. If a symbol has an exact match as both global and local for the same version tag, we give an error.
Otherwise, we look for an extern C++ or an extern Java exact match. If we find an exact match, we use it. If there is more than one exact match, we give a warning, and we use the first tag in the script which matches. If a symbol has an exact match as both global and local for the same version tag, we give an error.
Otherwise, we look through the wildcard patterns, ignoring “*” patterns. We look through the version tags in reverse order. For each version tag, we look through the global patterns and then the local patterns. We use the first match we find (i.e., the last matching version tag in the file).
Otherwise, we use the “*” pattern if there is one. We give a warning if there are multiple “*” patterns."
Patch makes wildcard matching to be in revered order and to follow after the regular naming matching.
Differential revision: http://reviews.llvm.org/D21894
llvm-svn: 274739
Previously, ch_size was read in host byte order, so if a host and
a target are different in byte order, we would produce a corrupted
output.
llvm-svn: 274729
The build otherwise fails with:
[ 39%] Building CXX object
tools/lld/ELF/CMakeFiles/lldELF.dir/OutputSections.cpp.o
/export/gnu/import/git/llvm/tools/lld/ELF/OutputSections.cpp: In
member function ‘void
lld:🧝:GnuHashTableSection<ELFT>::addSymbols(std::vector<std::pair<lld:🧝:SymbolBody*,
long unsigned int> >&)’:
/export/gnu/import/git/llvm/tools/lld/ELF/OutputSections.cpp:585:8:
error: inconsistent deduction for ‘auto’: ‘auto’ and then
‘__gnu_cxx::__normal_iterator<std::pair<lld:🧝:SymbolBody*, long
unsigned int>*, std::vector<std::pair<lld:🧝:SymbolBody*, long
unsigned int> > >’
Reported by: H. J. Liu
llvm-svn: 274518
This is PR28358
According to
https://www.akkadia.org/drepper/dsohowto.pdf
"The fourth point, the VERS 1.0 version being referred to in the VERS 2.0 definition, is not really important in symbol versioning. It marks the predecessor relationship of the two versions and it is done to maintain the similar- ities with Solaris’ internal versioning. It does not cause any problem it might in fact be useful to a human reader so predecessors should always be mentioned."
Patch partially reverts 273423 "[ELF] - Implemented version script hierarchies.",
version references are just ignored now.
Differential revision: http://reviews.llvm.org/D21888
llvm-svn: 274345
In general, we accept both -foo and --foo as command line options,
but if an option is a single letter option, we don't want to allow
double dashes because GNU linkers don't accept such combination.
llvm-svn: 274219
Option has next description (http://linux.die.net/man/1/ld):
"--unresolved-symbols=method
Determine how to handle unresolved symbols. There are four possible values for method
according to documentation:
ignore-all: Do not report any unresolved symbols.
report-all: Report all unresolved symbols. This is the default.
ignore-in-object-files: Report unresolved symbols that are contained in shared libraries, but ignore them if they come from regular object files.
ignore-in-shared-libs: Report unresolved symbols that come from regular object files, but ignore them if they come from shared libraries."
Since report-all is default and we traditionally do not report about undefined symbols in lld,
report-all does not report about undefines from DSO.
ignore-in-object-files also does not do that. Handling of that option differs from what gnu linkers do.
Option works in next way in lld:
ignore-all: Do not report any unresolved symbols.
report-all: Report all unresolved symbols except symbols from DSOs. This is the default.
ignore-in-object-files: The same as ignore-all.
gnore-in-shared-libs: The same as report-all.
This is PR24524.
Differential revision: http://reviews.llvm.org/D21794
llvm-svn: 274123
Previously BC files were not checked for the same platform etc,
That lead to confusing error "Invalid section header entry size (e_shentsize) in ELF header" when
mixing files for different architectures.
Patch fixes PR28324.
Differential revision: http://reviews.llvm.org/D21832
llvm-svn: 274113
So that users are not forced to pass `-m` on the command line
when the inputs are all bitcode.
PR: 28268
Differential Revision: http://reviews.llvm.org/D21779
llvm-svn: 274107
We allowed the function to return a vector that contains nullptrs
which is weird. This change makes the function to return only
defined symbols.
Differential Revision: http://reviews.llvm.org/D21828
llvm-svn: 274099
Example:
VERSION_1.0 {
global: foo*;
local: *; }
now correctly matches all the symbols which name starts with
`foo`.
Differential Revision: http://reviews.llvm.org/D21732
llvm-svn: 274091
Previously, we initialized Config->EKind and Config->EMachine when
we instantiate ELF objects. That was not an ideal location to do that
because the logic was buried too deep inside a concrete logic.
This patch moves the code to the driver so that the initialization
becomes explicit.
Differential Revision: http://reviews.llvm.org/D21784
llvm-svn: 274089
t is possible to create new version of symbol instead of depricated one
using combination of version script and asm commands. For example:
__asm__(".symver b_1,b@LIBSAMPLE_1.0");
int b_1() { return 10; }
__asm__(".symver b_2,b@@LIBSAMPLE_2.0");
int b_2() { return 20; }
This code makes b_2() to be default implementation for b().
b_1() is used for compatibility with binaries compiled against
library of older version LIBSAMPLE_1.0.
This patch implements support for above functionality in lld.
Differential revision: http://reviews.llvm.org/D21681
llvm-svn: 274002
Option checks for cases where a version script explicitly lists
a symbol, but the symbol is not defined and errors out such
cases if any.
Differential revision: http://reviews.llvm.org/D21745
llvm-svn: 273998
Previously, we searched for a .so file from all library paths and
then searched for a .a file. That logic is wrong. What we need to
do is to look for a .so and a .a for each library path.
llvm-svn: 273846
These references are used to implement MachO/x64-64 subtractor relocations
where the minuend is being fixed up, rather than the subtrahend. The 64-bit
version was not previously supported, the 32-bit version was partially
implemented but contained bugs not caught by existing test cases. This
patch fixes both functionality and test coverage.
llvm-svn: 273759
Previously the next sample script would generate 2 entries in
Config->SymbolVersions with the same version name.
VERSION {
global: c;
};
That happened because parseVersionSymbols() was called twice.
At first for "global:" and since there is no local tag, it was called again.
Patch fixes the issue, testcase was updated to demonstrate.
Differential revision: http://reviews.llvm.org/D21640
llvm-svn: 273663
Patch implements support of zlib style compressed sections.
SHF_COMPRESSED flag is used to recognize that decompression is required.
After that decompression is performed and flag is removed from output.
Differential revision: http://reviews.llvm.org/D20272
llvm-svn: 273661
The patch adds one more partition to the MIPS GOT. This time it is for
TLS related GOT entries. Such entries are located after 'local' and 'global'
ones. We cannot get a final offset for these entries at the time of
creation because we do not know size of 'local' and 'global' partitions.
So we have to adjust the offset later using `getMipsTlsOffset()` method.
All MIPS TLS relocations which need GOT entries operates MIPS style GOT
offset - 'offset from the GOT's beginning' - MipsGPOffset constant. That
is why I add new types of relocation expressions.
One more difference from othe ABIs is that the MIPS ABI does not support
any TLS relocation relaxations. I decided to make a separate function
`handleMipsTlsRelocation` and put MIPS TLS relocation handling code
there. It is similar to `handleTlsRelocation` routine and duplicates its
code. But it allows to make the code cleaner and prevent pollution of
the `handleTlsRelocation` by MIPS 'if' statements.
Differential Revision: http://reviews.llvm.org/D21606
llvm-svn: 273569
Patch by Shridhar Joshi.
This option provides names of all the link time modules which define and
reference symbols requested by user. This helps to speed up application
development by detecting references causing undefined symbols.
It also helps in detecting symbols being resolved to wrong (unintended)
definitions in case of applications containing multiple definitions for
same symbols with different types, bindings.
Implements PR28226.
llvm-svn: 273536
Peter Smith found while trying to support thunk creation for ARM that
LLD sometimes creates broken thunks for MIPS. The cause of the bug is
that we assign file offsets to input sections too early. We need to
create all sections and then assign section offsets because appending
thunks changes file offsets for all following sections.
This patch separates the pass to assign file offsets from thunk
creation pass. This effectively reverts r265673.
Differential Revision: http://reviews.llvm.org/D21598
llvm-svn: 273532
This fixes PR28218. Thanks to Rafael for spotting a failure in
the SHARED_LIBS build!
Differential Revision: http://reviews.llvm.org/D21577
llvm-svn: 273451
Patch implements hierarchies for version scripts.
This allows to handle script files with dependencies, like next one has:
LIBSAMPLE_1.0{
global:
a;
};
LIBSAMPLE_2.0
{
global:
b;
}LIBSAMPLE_1.0;
Differential revision: http://reviews.llvm.org/D21556
llvm-svn: 273423
For next version script:
VER1{
global:
a;
};
VER2{
global:
a;
};
gold would produce warning like:
"warning: using 'VER1' as version for 'a' which is also named in version 'VER2' in script."
Documentation also says we do not want this duplications (https://people.freebsd.org/~deischen/symver/library_versioning.txt):
"Note that you do not want to duplicate symbols in the map file. The .symver directives are all that is required to add compatibility
symbols into old versions."
This patch restricts such mixing and makes lld to produce error in this case.
Differential revision: http://reviews.llvm.org/D21555
llvm-svn: 273396
Previously, relocations for MIPS were scanned twice; once in regular
scanRelocs() and the other is in scanRelocsForThunks. In the former
function, we computed types of relocations and skipped R_THUNK relocations.
In the latter function, we computed the same value again and skipped
all but R_THUNK relocations. It was wasteful. This patch fixes that.
Now R_THUNK relocations are handled in the regular manner.
llvm-svn: 273346
This is a follow-up patch to r273218. GNU ld accepts both "--" and "-"
for all multi-letter options except "-o". This patch makes lld compatible
with that behavior.
llvm-svn: 273256
`Inst` and `Op` variables are removed since they are not always
point to an instruction nor an operand. For 5-byte MOV instruction,
Op points to an instruction, which is confusing.
llvm-svn: 273246
This patch is to rewrite the function with a table-lookup-ish approach
so that it can read as a series of "convert this pattern to this" pattern.
llvm-svn: 273238
GNU ld's manual page says that all options whose names are
multiple letters, except those who start with "o", can start
either with one or two dashes.
llvm-svn: 273218
With fix:
-soname flag was not set in testcase. Hash calculated for base def was different on local
and bot machines because filename fos used for calculating.
Initial commit message:
Patch implements basic support of versioned symbols.
There is no wildcards patterns matching except local: *;
There is no support for hierarchies.
There is no support for symbols overrides (@ vs @@ not handled).
This patch allows programs that using simple scripts to link and run.
Differential revision: http://reviews.llvm.org/D21018
llvm-svn: 273152
Rafael Espindola