In preparation for inserting Thunks into InputSectionDescriptions this
simple change associates added Thunks with a vector of InputSections instead
of an OutputSection. As of now we are just using OutputSection::Sections.
Differential Revision: https://reviews.llvm.org/D33832
llvm-svn: 304782
Previously LLD would fail for case when there are multiple comdats and -r.
That happened because it merged all ".group" (SHT_GROUP) sections into single
output, producing broken result. Such sections may have similar name, alignment and flags
and other properties. We need to produce separate output section for each such input one.
Differential revision: https://reviews.llvm.org/D33643
llvm-svn: 304769
Traditionally, it has been defined in crtbegin.o, which is typically
provided by libgcc or as part of the C library on some systems. However,
but there's no principled reason for it to be there. We optionaly
define this symbol, which can be used on platforms that don't provide
__dso_handle in crtbegin.o or which don't use crtbegin.o at all.
Differential Revision: https://reviews.llvm.org/D33856
llvm-svn: 304732
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
This is PR33289.
Previously LLD leaved section naming as is and that lead to wrong result,
because we decompress sections when using -r,
and hence should remove ".z" prefix.
Differential revision: https://reviews.llvm.org/D33885
llvm-svn: 304711
This change alters the sorting for OutputSections with the SHF_LINK_ORDER
flag in OutputSection::finalize() to use the InputSectionDescription
representation and not the OutputSection::Sections representation.
Differential revision: https://reviews.llvm.org/D33772
llvm-svn: 304700
This reverts commit r304561 and re-lands r303490 & co.
The fix was to use "SymbolName" when translating LLD's internal export
list to lib/Object's short export struct. The SymbolName reflects the
actual symbol name, which may include fastcall and stdcall mangling bits
not included in the /EXPORT or .def file EXPORTS name:
@@ -434,8 +434,7 @@ std::vector<COFFShortExport> createCOFFShortExportFromConfig() {
std::vector<COFFShortExport> Exports;
for (Export &E1 : Config->Exports) {
COFFShortExport E2;
- E2.Name = E1.Name;
+ // Use SymbolName, which will have any stdcall or fastcall qualifiers.
+ E2.Name = E1.SymbolName;
E2.ExtName = E1.ExtName;
E2.Ordinal = E1.Ordinal;
E2.Noname = E1.Noname;
llvm-svn: 304573
The .def file parser changes I reverted broke this test case, and
exported "__imp__foo" instead of "__imp__foo@8". This was
http://crbug.com/728726.
llvm-svn: 304572
This reverts commits r303490, r303491, r303493, and r303494.
This caused http://crbug.com/728726. Essentially, exporting stdcall
functions doesn't appear to work after this change. Reduced test case
soon.
llvm-svn: 304561
Spec says: (http://www.sco.com/developers/gabi/latest/ch4.sheader.html)
sh_info
This member holds extra information, whose interpretation depends on the section type.
If the sh_flags field for this section header includes the attribute SHF_INFO_LINK,
then this member represents a section header table index.
SHF_INFO_LINK
The sh_info field of this section header holds a section header table index.
Since sh_info for SHT_REL[A] sections should contain the section header index of the
section to which the relocation applies, this is
consistent with spec to put this flag. Behavior matches both bfd and gold as well.
Differential revision: https://reviews.llvm.org/D33763
llvm-svn: 304531
Object files have symbol records not aligned to any particular
boundary (e.g. 1-byte aligned), while PDB files have symbol
records padded to 4-byte aligned boundaries. Since they share
the same reading / writing code, we have to provide an option to
specify the alignment and propagate it up to the producer or
consumer who knows what the alignment is supposed to be for the
given container type.
Added a test for this by modifying the existing PDB -> YAML -> PDB
round-tripping code to round trip symbol records as well as types.
Differential Revision: https://reviews.llvm.org/D33785
llvm-svn: 304484
This is probably the correct location for it: next to
fabricateDefaultCommands. If we don't have a linker script, we
fabricate one. If we have one, we patch it.
llvm-svn: 304436
This is PR33243. R_GOTONLY_PC_FROM_END was not in a list of link time constant
expressions and that was a result of confusiing messages like PR shows:
/usr/bin/ld.lld: error: /usr/lib/go/src/runtime/alg.go:47:
can't create dynamic relocation R_386_GOTPC against local symbol in readonly segment defined in /tmp/nice/go-link-597453838/go.o
Though in reality we just should not have try to create a dynamic relocation for this case at all.
Patch fixes the issue.
Differential revision: https://reviews.llvm.org/D33717
llvm-svn: 304393
We were looking up sections by name during expression evaluation. By
keeping track of forward declarations we can do the lookup during
script parsing.
Doing the lookup earlier will be more efficient when assignAddresses
is run twice and removes two uses of OutputSections.
llvm-svn: 304381
Before InputSectionBase had an OutputSection pointer, but that was not
always valid. For example, if it was a merge section one actually had
to look at MergeSec->OutSec.
This was brittle and caused bugs like the one fixed by r304260.
We now have a single Parent pointer that points to an OutputSection
for InputSection, but to a SyntheticSection for merge sections and
.eh_frame. This makes it impossible to accidentally access an invalid
OutSec.
llvm-svn: 304338
We would crash if a SHF_LINK_ORDER section pointed to a non
InputSection section. Since those sections are not merged in order,
SHF_LINK_ORDER is pretty meaningless and we can error on that case.
llvm-svn: 304327
This change converts the writing of the .ARM.exidx sentinel section to use
the InputSectionDescriptions instead of OutputSection::Sections this is in
preparation for the retirement of OutputSection::Sections.
Differential Revision: https://reviews.llvm.org/D33500
llvm-svn: 304289
This happens when attempting to link shared libraries using exceptions on
MIPS. It requires -z notext because clang generates R_MIPS_64 relocations
inside .eh_frame.
The crash happened because for EhInputSection the OutSec member is null.
Patch by Alexander Richardson!
llvm-svn: 304260
When there is a linker script with .ARM.exidx in the SECTIONS
command we must add the .ARM.exidx sentinel section to the
InputSectionDescriptions as well as to OutputSection::Sections.
Differential Revision: https://reviews.llvm.org/D33496
llvm-svn: 304206
I found that during visual inspection of code while wrote different patch.
Script in testcase probably have nothing common with real life, but
we segfault currently using it.
If output section is known NOBITS, there is no need to create
writers threads for doing nothing or proccess any filler logic that
is useless here. We can just early return, that is what this patch do.
DIfferential revision: https://reviews.llvm.org/D33646
llvm-svn: 304192
InputSections may contain MergeInputSection members which trigger
a segmentation fault when trying to cast them to InputSection.
Differential Revision: https://reviews.llvm.org/D33628
llvm-svn: 304189
While the following expression is handled fine:
PROVIDE_HIDDEN(newsym = oldsym + address);
The following expression triggers an error because the expression
is evaluated as absolute:
PROVIDE_HIDDEN(newsym = ALIGN(oldsym, CONSTANT(MAXPAGESIZE)) + address);
To avoid this error, we use late evaluation for ALIGN by making the
alignment an attribute of the expression itself.
Differential Revision: https://reviews.llvm.org/D33629
llvm-svn: 304185
Now that we are trying to use the linker script representation as the
canonycal one, there are a few loops looking for just OutputSectionCommands.
Create a vector with just the OutputSectionCommands once that is
stable to simplify the rest of the code.
llvm-svn: 304181
This is PR33052, "Bug 33052 - -r eats comdats ".
To fix it I stop removing group section from out when -r is given
and fixing SHT_GROUP content when writing it just like we do some
other fixup, e.g. for Rel[a]. (it needs fix for section indices that
are in group).
Differential revision: https://reviews.llvm.org/D33485
llvm-svn: 304140
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
On SPARC, .plt is both writeable and executable. The current way
sections are sorted means that lld puts it after .data/.bss. but it
really needs to be close to .test to make sure branches into .plt
don't overflow. I'd argue that because .bss is supposed to come last
on all architectures, we should change the default sort order such
that writable and executable sections come before sections that are
just writeable. read-only executable sections should still come after
sections that are just read-only of course. This diff makes this
change.
llvm-svn: 304008
I found this when builded llc binary using gcc 5.4.1 + LLD.
gcc produces duplicate entries in .debug_gnu_pubtypes section, ex:
UnifyFunctionExitNodes.cpp.o has:
0x0000ac07 EXTERNAL TYPE "std::success_type<void*>"
0x0000ac07 EXTERNAL TYPE "std::success_type<void*>"
clang produces single entry here:
0x0000d291 EXTERNAL TYPE "std::__success_type<void *>"
If we link output from gcc with LLD, that would produce excessive duplicate
entries in .gdb_index constant pool area. That does not seem affect gdb work,
but makes .gdb_index larger than it can be.
I also checked that gold filters out such duplicates too. Patch fixes it.
Differential revision: https://reviews.llvm.org/D32647
llvm-svn: 303975
https://sourceware.org/gdb/onlinedocs/gdb/Index-Section-Format.html says:
"A CU vector in the constant pool is a sequence of offset_type values.
The first value is the number of CU indices in the vector.
Each subsequent value is the index and symbol attributes of a CU in the CU list."
Previously we keeped 2 values until the end, what was useless.
Initially was a part of D32647, though it is possible to split out.
Patch do that.
Differential revision: https://reviews.llvm.org/D33551
llvm-svn: 303973
In this way, the content and the flag is always consistent, which I
think better than removing the bit when input sections reaches the Writer.
llvm-svn: 303926
Originally this was intended to be set up so that when linking
a PDB which refers to a type server, it would only visit the
PDB once, and on subsequent visitations it would just skip it
since all the records had already been added.
Due to some C++ scoping issues, this was not occurring and it
was revisiting the type server every time, which caused every
record to end up being thrown away on all subsequent visitations.
This doesn't affect the performance of linking clang-cl generated
object files because we don't use type servers, but when linking
object files and libraries generated with /Zi via MSVC, this means
only 1 object file has to be linked instead of N object files, so
the speedup is quite large.
llvm-svn: 303920
If you pass /delayload:<dllname> to the COFF linker, it creates thunks
so that DLLs are loaded when they are used for the first time instead of
load-time.
This mechanism do not work for data symbols as there's no way to trap
acccesses to data imported from DLLs. (Technically, I think if we do not
initially map dllimport tables in memory, we could actually trap accesses
and delay-load data symbols, but that's not what Windows do.)
This patch is to report an error when you try to delay-load data symbols.
Fixes https://bugs.llvm.org/show_bug.cgi?id=33106
Differential Revision: https://reviews.llvm.org/D33557
llvm-svn: 303890
This is a different implementation than r303225 (which was reverted
in r303270, re-submitted in r303304 and then re-reverted in r303527).
In the previous patch, I tried to add Live bit to each dllimported
symbol. It turned out that it didn't work with "oldnames.lib" which
contains a lot of weak aliases to dllimported symbols.
The way we handle weak aliases is to check if undefined symbols
can be resolved using weak aliases, and if so, memcpy the Defined
symbols to weak Undefined symbols, so that any references to weak
aliases automatically see defined symbols instead of undefined ones.
This memcpy happens before MarkLive kicks in.
That means we may have multiple copies of dllimported symbols. So
turning on one instance's Live bit is not enough.
This patch moves the Live bit to dllimport file. Since multiple
copies of dllsymbols still point to the same file, we can use it as the
central repository to keep track of liveness.
Differential Revision: https://reviews.llvm.org/D33520
llvm-svn: 303814
It is not clear why a synthetic section wants to use padding defined
in the linker script. The padding is for the space between sections.
It was also missing a test.
llvm-svn: 303812
This is the only place we use threads for ICF. The intention of this code
was to split an input vector into 256 shards and process them in parallel.
What the code was actually doing was to split an input into 257 shards,
process the first 256 shards in parallel, and the remaining one in serial.
That means this code takes ceil(256/n)+1 instead of ceil(256/n) where n
is the number of available CPU cores. The former converges to 2 while
the latter converges to 1.
This patches fixes the above issue.
llvm-svn: 303797
Summary:
This is required on some platforms, as GNU libstdc++ std::call_once is known to be buggy.
This fixes operation of LLD on at least NetBSD and perhaps OpenBSD and Linux PowerPC.
The same change has been introduced to LLVM and LLDB.
Reviewers: ruiu
Reviewed By: ruiu
Subscribers: emaste, #lld
Tags: #lld
Differential Revision: https://reviews.llvm.org/D33508
llvm-svn: 303788
A variable `ComdatGroup` is not supposed to contain a large number of
items. Even when linking clang, it ends up having only 300K strings.
It doesn't make sense to use CachedHashStringRef for this hash table.
This patch has neutral or slightly positive impact on performance while
reducing code complexity.
llvm-svn: 303787
This reduces how many times we have to map from OutputSection to
OutputSectionCommand. It is a required step to moving
clearOutputSections earlier.
In order to always use writeTo in OutputSectionCommand we have to call
fabricateDefaultCommands for -r links and move section compression
after it.
llvm-svn: 303784
LazyRandomTypeCollection is designed for random access, and in
order to provide this it lazily indexes ranges of types. In the
case of types from an object file, there is no partial index
to build off of, so it has to index the full stream up front.
However, merging types only requires sequential access, and when
that is needed, this extra work is simply wasted. Changing the
algorithm to work on sequential arrays of types rather than
random access type collections eliminates this up front scan.
llvm-svn: 303707
Once the dummy linker script is created, we want it to be used for
everything to avoid having two redundant representations that can get
out of sync.
We were already clearing OutputSections. With this patch we clear the
Sections vector of every OutputSection.
llvm-svn: 303703
By the time we get to linker scripts, all special InputSectionBase
should have been combined into synthetic sections, which are a type of
InputSection. The net result is that we can use InputSection in a few
places that were using InputSectionBase.
llvm-svn: 303702
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
Previous algotirhm assumed that types and ids are in a single
unified stream. For inputs that come from object files, this
is the case. But if the input is already a PDB, or is the result
of a previous merge, then the types and ids will already have
been split up, in which case we need an algorithm that can
accept operate on independent streams of types and ids that
refer across stream boundaries to each other.
Differential Revision: https://reviews.llvm.org/D33417
llvm-svn: 303577
This reverts commit r303304 because it looks like the change
introduced a crash bug. At least after that change, LLD with thinlto
crashes when linking Chromium.
llvm-svn: 303527
This is split up into two commits.
This commit removes the DEF parser from LLD
See the previous commit for the creation in LLVM.
Reviewers: ruiu
Differential Revision: https://reviews.llvm.org/D32689
llvm-svn: 303491
This was originally reverted because it was a breaking a bunch
of bots and the breakage was not surfacing on Windows. After much
head-scratching this was ultimately traced back to a bug in the
lit test runner related to its pipe handling. Now that the bug
in lit is fixed, Windows correctly reports these test failures,
and as such I have finally (hopefully) fixed all of them in this
patch.
llvm-svn: 303446
This is a squash of ~5 reverts of, well, pretty much everything
I did today. Something is seriously broken with lit on Windows
right now, and as a result assertions that fire in tests are
triggering failures. I've been breaking non-Windows bots all
day which has seriously confused me because all my tests have
been passing, and after running lit with -a to view the output
even on successful runs, I find out that the tool is crashing
and yet lit is still reporting it as a success!
At this point I don't even know where to start, so rather than
leave the tree broken for who knows how long, I will get this
back to green, and then once lit is fixed on Windows, hopefully
hopefully fix the remaining set of problems for real.
llvm-svn: 303409
Right now we have multiple notions of things that represent collections of
types. Most commonly used are TypeDatabase, which is supposed to keep
mappings from TypeIndex to type name when reading a type stream, which
happens when reading PDBs. And also TypeTableBuilder, which is used to
build up a collection of types dynamically which we will later serialize
(i.e. when writing PDBs).
But often you just want to do some operation on a collection of types, and
you may want to do the same operation on any kind of collection. For
example, you might want to merge two TypeTableBuilders or you might want
to merge two type streams that you loaded from various files.
This dichotomy between reading and writing is responsible for a lot of the
existing code duplication and overlapping responsibilities in the existing
CodeView library classes. For example, after building up a
TypeTableBuilder with a bunch of type records, if we want to dump it we
have to re-invent a bunch of extra glue because our dumper takes a
TypeDatabase or a CVTypeArray, which are both incompatible with
TypeTableBuilder.
This patch introduces an abstract base class called TypeCollection which
is shared between the various type collection like things. Wherever we
previously stored a TypeDatabase& in some common class, we now store a
TypeCollection&.
The advantage of this is that all the details of how the collection are
implemented, such as lazy deserialization of partial type streams, is
completely transparent and you can just treat any collection of types the
same regardless of where it came from.
Differential Revision: https://reviews.llvm.org/D33293
llvm-svn: 303388
This converts the last (chronologically) user of OutputSections to use
the linker script commands instead.
The idea is to convert all uses after fabricateDefaultCommands, so
that we have a single representation.
llvm-svn: 303384
Our output is not compatible with the Binding feature, so make it
explicit that.
Differential Revision: https://reviews.llvm.org/D33336
llvm-svn: 303378
Previously, LLD-produced executables had IAT (Import Address Table) and
ILT (Import Lookup Table) as separate chunks of data, although their
contents are identical. My interpretation of the COFF spec when I wrote
the COFF linker is that they need to be separate tables even though they
are the same.
But Peter found that the Windows loader is fine with executables in
which IAT and ILT are merged. This is a patch to merge IAT and ILT.
I confirmed that an lld-link self-hosted with this patch works fine.
Fixes https://bugs.llvm.org/show_bug.cgi?id=33064
Differential Revision: https://reviews.llvm.org/D33326
llvm-svn: 303374
The import lists are already binned by DLL name, so there's no need to
deduplicate here.
Differential Revision: https://reviews.llvm.org/D33330
llvm-svn: 303371
We've been using make<> to allocate new objects in ELF. We have
the same function in COFF, but we didn't use it widely due to
negligence. This patch uses the function in COFF to close the gap
between ELF and COFF.
llvm-svn: 303357
GetSection is a template because write calls relocate.
relocate has two parts. The non alloc code really has to be a
template, as it is looking a raw input file data.
The alloc part is only a template because of getSize.
This patch folds the value of getSize early, detemplates
getRelocTargetVA and splits relocate into a templated non alloc case
and a regular function for the alloc case. This has the nice advantage
of making sure we collect all the information we need for relocations
before getting to InputSection::relocateNonAlloc.
Since we know got is alloc, it can just call the function directly and
avoid the template.
llvm-svn: 303355
Peter Smith