We should be using one of BIND_OPCODE_SET_DYLIB_SPECIAL_IMM, BIND_OPCODE_SET_DYLIB_ORDINAL_IMM,
and BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB depending on whether ordinals are <= 0, <= 15, > 15.
This matches the behaviour of ld64.
llvm-svn: 278407
We already had logic for binding opcodes had the same addend as last time. This adds
the cases where the ordinal, symbol name, type, and segment offsets are the same as
the last emitted ordinal.
This gets us one step closer to emitting rebase opcodes as compressed as ld64 can manage.
llvm-svn: 278405
Currently we do this when an atom is used, but we need to do it when a
dylib is referenced on the cmdline as this matches ld64.
This fixes much confusion over which maps are indexed with installName
vs path. There is likely other confusion so i'll be seeing if i can remove
path() completely in a future commit as path() shouldn't really be needed by anyone.
llvm-svn: 278396
A future commit will change when we choose to add an LC_LOAD_DYLIB to the final image. Currently
we do this when an atom is used, but we need to do it when a dylib is referenced on the cmdline as
this matches ld64.
To allow this change, libsystem (and other future yaml files representing dylibs) need to be dylibs
so that the loader can see to add them to the referenced dylib list.
llvm-svn: 278386
A version of 0x1000 is 0.16.0, not 1.0.0 as the comment said. Fix the
value to match the comment, and also the one test case which had this
wrong.
llvm-svn: 278381
An upcoming commit will change how we choose to reference a dylib. Currently
dylibs are only given an LC_LOAD_DYLIB in the final image if an atom is used.
This is different from ld64 which adds the load command when the dylib is referenced
on the cmdline.
In order to change this behaviour, we need libSystem.yaml to actually contain a mach header
so that it is parsed as a dylib, instead of currently being parsed as a normalised file.
To get a mach header, we also require an arch, so now we have one libsystem per arch and
all the tests have been updated to choose the correct one.
llvm-svn: 278372
Using vmsize to populate this file works when outputing MachO images, but fails
when outputting relocatable objects. This patch fixes the computation to use
file offsets, which works for both output types.
Fixes <rdar://problem/27727666>
llvm-svn: 278297
MIPS ISA encoded using two ELF flags: general architecture flag like
EF_MIPS_ARCH_32, EF_MIPS_ARCH_64R6 etc and optional machine variant flag
like EF_MIPS_MACH_4111, EF_MIPS_MACH_OCTEON3 etc. When we check
compatibility between two input files and deduce ELF flags for generated
output we need to take into account both of these flags.
llvm-svn: 278230
SIZEOF_HEADERS - Return the size in bytes of the output file’s headers.
It is is a feature used in FreeBsd script, for example.
There is a discussion on PR28688 page about it.
Differential revision: https://reviews.llvm.org/D23165
llvm-svn: 278204
Previously, we incrementally updated the reuslting flag as we check
file flags, so it was not very clear who is updating what flags.
This patch makes them pure functions -- that has no side effect and
don't update arguments to improve readability.
Now each function construct a patial result, and all resutls are then
bitwise-OR'ed to construct the final result.
This patch also creates a new file, Mips.cpp, to move all these
MIPS functions to a separate file.
Differential Revision: https://reviews.llvm.org/D23249
llvm-svn: 278042
I faced that when tried to link FreeBSD kernel.
It was "duplicate symbol: _edata in (internal) and (internal)" error.
_data was a shared symbol that came from hack.so. At first it was replaced with DefinedRegular by the code
disabled in this patch and later when script tried to define the same symbol - the error was shown.
In the same situation (as given in testcase) ld defines them as UND. gold defines as ABS with zero value.
Patch just disables any operations of creating these symbols if script do layout.
Differential revision: https://reviews.llvm.org/D23206
llvm-svn: 277986
The patch extends the `getMipsEFlags` function. Now in that function
we iterate over all object files, parse ELF header flags and merge them.
If a file is incompatible with previously analyzed ones we show an error
or warning. That can happen if, for example, we try to link files with
incompatible ABI, ISA, NAN encoding etc.
There is an alternative solution. We can check and merge flags and
reject incompatible input modules in the `isCompatible` function which
is called from the `SymbolTable::addFile` method. But in that case we
have to save and keep somewhere a merged ELF flags combination to use it
later in the writer.
Differential Revision: http://reviews.llvm.org/D23161
llvm-svn: 277911
The export trie was being emitted in the order the nodes were
added to the vector, but instead needs to be visited in the order
that the nodes are traversed. This matches the behaviour of ld64.
llvm-svn: 277869
Don't blindly OR in the new value, but clear the existing one, since it can be
nonzero. Read out the existing value before, and add into the desired offset.
(The add is done outside of the applyMOV, to handle potential overflow between
the two.)
Patch by Martin Storsjö!
llvm-svn: 277846
The opcode for the bl branches can initially be F000 F800, i.e.
the J1 and J2 bits are already set. Therefore mask these bits out
before or'ing in the new bits.
Patch by Martin Storsjö!
llvm-svn: 277836
ASSERT(exp, message)
Ensure that exp is non-zero. If it is zero, then exit the linker with an error
code, and print message.
ASSERT is useful and was seen in few projects in the wild.
Differential revision: https://reviews.llvm.org/D22912
llvm-svn: 277710
According to spec:
"SORT_BY_ALIGNMENT will sort sections into descending order by
alignment before placing them in the output file"
Previously they were sorted into ascending order.
llvm-svn: 277706
With the previous change, it is now obvious that readProvide in
this context appended new commands to a wrong command list.
It was mistakenly adding new commands to the top level.
Thus, all commands inside output section descriptions were
interpreted as they were written on top level.
PROVIDE command naturally requires symbol assignment support
in the output section description. We don't have that one yet.
I removed the implementation because there's no way to fix it now.
We can resurrect the test once we support the symbol assignment
(with a modification to detect errors that we failed to find as
described.)
llvm-svn: 277687
Previously, a decimal filler expression is interpreted as a byte value.
Gold on the other hand use it as a 32-bit big-endian value.
This patch fixes the compatibility issue.
Differential Revision: https://reviews.llvm.org/D23142
llvm-svn: 277680
Previously we supported only sorting by name.
When there are nested section sorting commands in linker script, there can be at most 1
level of nesting for section sorting commands.
SORT_BY_NAME (SORT_BY_ALIGNMENT (wildcard section pattern)). It will sort the input
sections by name first, then by alignment if 2 sections have the same name.
SORT_BY_ALIGNMENT (SORT_BY_NAME (wildcard section pattern)). It will sort the input
sections by alignment first, then by name if 2 sections have the same alignment.
SORT_BY_NAME (SORT_BY_NAME (wildcard section pattern)) is treated the same as SORT_
BY_NAME (wildcard section pattern).
SORT_BY_ALIGNMENT (SORT_BY_ALIGNMENT (wildcard section pattern)) is treated the
same as SORT_BY_ALIGNMENT (wildcard section pattern).
All other nested section sorting commands are invalid.
Patch implements that all above.
Differential revision: https://reviews.llvm.org/D23019
llvm-svn: 277583
Mergeable sections with size zero are useless because they don't
actually contain data, and therefore there's no merit ot merge them.
However, in reality, there are object files in the wild containing
such sections. Currently, LLD can't handle them proerply.
This patch makes LLD to handle such sections as if they are non-
mergeable to fix the issue.
Fixes bug 28822.
llvm-svn: 277568
This is a bit of an odd feature. It is normally used in
. = SEGMENT_START(seg, val);
In bfd it evaluates to val or to the value of the corresponding
-T<seg>-segment. Note that the -T<seg>-segment in bfd doesn't actually
change the segment address, just the value this evaluates too,
including in the default linker script.
In gold the -T<seg>-segment options do change the segment address and
seeing this expressions in linker scripts disables the options.
For new this just always evaluates the expression to val.
llvm-svn: 277014
The previous run line depended on libSystem.dylib being present, which it's not
on non-darwin platforms. The new run line uses libSystem.yaml instead.
llvm-svn: 276999
Some scripts can contain SORT(CONSTRUCTORS) expression:
https://svnweb.freebsd.org/base/head/sys/conf/ldscript.amd64?revision=284870&view=markup#l152
for ELF it just a nop:
"When linking object file formats which do not support arbitrary sections, such as ECOFF and XCOFF, the linker will automatically recognize C++ global constructors and destructors by name. For these object file formats, the CONSTRUCTORS command tells the linker to place constructor information in the output section where the CONSTRUCTORS command appears. The CONSTRUCTORS command is ignored for other object file formats."
(http://www.sourceware.org/binutils/docs-2.10/ld_3.html)
So patch implements ignoring.
Differential revision: https://reviews.llvm.org/D22848
llvm-svn: 276965
This patch causes LLD to build stabs debugging symbols for files containing
DWARF debug info, and to propagate existing stabs symbols for object files
built using '-r' mode. This enables debugging of binaries generated by LLD
from MachO objects.
llvm-svn: 276921
In compare with what GNU linkers do (https://sourceware.org/binutils/docs/ld/Builtin-Functions.html),
this implementation simple:
Do not touch DATA_SEGMENT_ALIGN, it do what it do now - just aligns to the page boundary.
Parameters of DATA_SEGMENT_RELRO_END is ignored. That should be correct as it is usually just a 24 bytes
shift that allows to protect first 3 entries of got.plt with relro.
(https://svnweb.freebsd.org/base/head/sys/conf/ldscript.amd64?revision=284870&view=markup#l146).
DATA_SEGMENT_RELRO_END just aligns to the page boundary.
That is what expected because all sections that are not affected by relro should be on another memory page.
So at fact the difference with documented behavior is that we do not pad DATA_SEGMENT_ALIGN.
3 entries of got.plt are uncovered by relro, but functionality is simple and equal to lld behavior
for case when script is not given.
Differential revision: https://reviews.llvm.org/D22813
llvm-svn: 276778
We can simplify the evaluation of DATA_SEGMENT_ALIGN
just to simple align(). That way it will work exactly like we have in non-script case.
Change was suggested by Rafael Ávila de Espíndola
Differential revision: https://reviews.llvm.org/D22807
llvm-svn: 276745
This flag is implemented similarly to --reproduce in the ELF linker.
This patch implements /linkrepro by moving the cpio writer and associated
utility functions to lldCore, and using that implementation in both linkers.
One COFF-specific detail is that we store the object file from which the
resource files were created in our reproducer, rather than the resource
files themselves. This allows the reproducer to be used on non-Windows
systems for example.
Differential Revision: https://reviews.llvm.org/D22418
llvm-svn: 276719
PROVIDE request us to define a symbol only if it is referenced and is
not defined by any object included in the link. We created the
symbol in the symbol table no matter what.
Differential Revision: https://reviews.llvm.org/D22739
llvm-svn: 276592
Previously, we handled an expression as a vector of tokens. In other
words, an expression was a vector of uncooked raw StringRefs.
When we need a value of an expression, we used ExprParser to run
the expression.
The separation was needed essentially because parse time is too
early to evaluate an expression. In order to evaluate an expression,
we need to finalize section sizes. Because linker script parsing
is done at very early stage of the linking process, we can't
evaluate expressions while parsing.
The above mechanism worked fairly well, but there were a few
drawbacks.
One thing is that we sometimes have to parse the same expression
more than once in order to find the end of the expression.
In some contexts, linker script expressions have no clear end marker.
So, we needed to recognize balanced expressions and ternary operators.
The other is poor error reporting. Since expressions are parsed
basically twice, and some information that is available at the first
stage is lost in the second stage, it was hard to print out
apprpriate error messages.
This patch fixes the issues with a new approach.
Now the expression parsing is integrated into ScriptParser.
ExprParser class is removed. Expressions are represented as lambdas
instead of vectors of tokens. Lambdas captures information they
need to run themselves when they are created.
In this way, ends of expressions are naturally detected, and
errors are handled in the usual way. This patch also reduces
the amount of code.
Differential Revision: https://reviews.llvm.org/D22728
llvm-svn: 276574
Otherwhise undefined references to symbols defined in linker scripts
are never resolved.
Differential Revision: https://reviews.llvm.org/D22664
llvm-svn: 276536
Not all relocations from a .eh_frame that point to an executable
section should be ignored. In particular, the relocation finding the
personality function should not.
This is a reduction from trying to bootstrap a static lld on linux.
llvm-svn: 276329
It is called basic because:
CONSTANT expression can refer to COMMONPAGESIZE and MAXPAGESIZE.
This sizes are usually different and used for possible optimization of
memory consumption.
More details are here: https://sourceware.org/ml/binutils/2002-02/msg00265.html
We currently do not support this optimization, so both CONSTANT(MAXPAGESIZE)
and CONSTANT(COMMONPAGESIZE) just return Target->PageSize value.
DATA_SEGMENT_ALIGN and DATA_SEGMENT_END are used as a part of opt.
The latter one is just ignored now.
According to documentation DATA_SEGMENT_ALIGN has 2 possible
calculation, but since we do not support mentioned opt - it
is always calculated now as (ALIGN(MAXPAGESIZE) + (. & (MAXPAGESIZE - 1))).
In general this should work for now until we deside to support this opt.
Differential revision: https://reviews.llvm.org/D19663
llvm-svn: 276323
We no longer need it for relocations in .eh_frame.
The only relocations that point to .eh_frame are the ones trying to
find the output .eh_frame.
This actually fixes a bug in the symbol value code. It was not
handling -1 as an indicator for a piece not being included in the
output.
llvm-svn: 276175
LLD still does not produce a correct combination of MIPS ELF flags if
input files have different sets of ELF flags (i.e. EF_MIPS_ARCH_32 and
EF_MIPS_ARCH_32R2). But now we do not stick to "R2" ABI version and can
emit EF_MIPS_ARCH_32R6 for example.
llvm-svn: 276172
- R_ARM_TLS_LDM32
- R_ARM_TLS_LDO32
The local dynamic implementation and tests follows the same model as
the other ARM TLS models. The R_ARM_TLS_LDO32 is implemented as R_ABS
expr type as the getVA() for a TLS symbol will return the offset from the
start of the TLS block.
Differential Revision https://reviews.llvm.org/D22563
llvm-svn: 276123
Add relocations and identification functions for the Initial Exec
and Global Dynamic TLS model defined in Addenda to, and Errata in,
the ABI for the ARM Architecture.
ARM uses variant 1 of the thread local storage data
structures as defined in ELF Handling for Thread-Local Storage.
The "experimental" descriptor based model that can be selected in
gcc, but not clang with -mtls-dialect=gnu2 is not supported.
The relocations R_ARM_TLS_LE12 and R_ARM_TLS_IE12GP are not
supported, I know of no ARM Toolchain that supports these relocations
as they limit the size of the TLS block.
No code relaxation is supported as the standard ARM TLS model puts
the relocations on literal data.
Support for the local dynamic model will come in a follow up patch.
Differential Revision: https://reviews.llvm.org/D22462
llvm-svn: 276095
--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
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
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
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
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
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
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
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
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
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
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
Pete Cooper