Fixes check-llvm when bootstrapping.
Also remove mostly dead and most likely incorrect logic regarding preemption
of weak undefined symbols.
llvm-svn: 267314
Previously, we have re-implemented utility functions such as `expect`
or `next` in LinkerScript.cpp. This patch reuses the existing
implementation that is in ScriptParser.cpp.
llvm-svn: 267255
ScriptParserBase class is a container of collection of various methods
to parse linker script-ish text. It had a virtual method `run` to run
the parser. But we don't have to enforce its descendents to implement
that. It's up to them.
This patch removes pure virtual function `run`.
llvm-svn: 267246
The fix is to handle local symbols referring to SHF_MERGE sections.
Original message:
GC entries of SHF_MERGE sections.
It is a fairly direct extension of the gc algorithm. For merge sections
instead of remembering just a live bit, we remember which offsets
were used.
This reduces the .rodata sections in chromium from 9648861 to 9477472
bytes.
llvm-svn: 267233
This patch is to remove -lto-no-discard-value-names flag and
instead to use -save-temps as we discussed in the post-commit
review thread for r267020.
Differential Revision: http://reviews.llvm.org/D19437
llvm-svn: 267230
This patch only implements support for version scripts of the form:
{ [ global: symbol1; symbol2; [...]; symbolN; ] local: *; };
No wildcards are supported, other than for the local entry. Symbol versioning
is also not supported.
It works by introducing a new Symbol flag which tracks whether a symbol
appears in the global section of a version script.
This patch also simplifies the logic in SymbolBody::isPreemptible(), and
teaches it to handle the case where symbols with default visibility in DSOs
do not appear in the dynamic symbol table because of a version script.
Fixes PR27482.
Differential Revision: http://reviews.llvm.org/D19430
llvm-svn: 267208
These are properties of a symbol name, rather than a particular instance
of a symbol in an object file. We can simplify the code by collecting these
properties in Symbol.
The MustBeInDynSym flag has been renamed ExportDynamic, as its semantics
have been changed to be the same as those of --dynamic-list and
--export-dynamic-symbol, which do not cause hidden symbols to be exported.
Differential Revision: http://reviews.llvm.org/D19400
llvm-svn: 267183
It is a fairly direct extension of the gc algorithm. For merge sections
instead of remembering just a live bit, we remember which offsets were
used.
This reduces the .rodata sections in chromium from 9648861 to 9477472
bytes.
llvm-svn: 267164
It turns out that this will read data from the section to properly
handle Elf_Rel implicit addends.
Sorry for the noise.
Original messages:
Try to fix Windows lld build.
Move getRelocTarget to ObjectFile.
It doesn't use anything from the InputSection.
llvm-svn: 267163
llvm\tools\lld\ELF\MarkLive.cpp(49): error C2872: 'ObjectFile': ambiguous symbol
llvm\tools\lld\elf\InputFiles.h(100): note: could be 'lld:🧝:ObjectFile'
llvm\include\llvm/Object/IRObjectFile.h(26): note: or 'llvm::object::ObjectFile'
llvm\tools\lld\ELF\MarkLive.cpp(133): note: see reference to function template instantiation
'void forEachSuccessor<ELFT>(lld:🧝:InputSection<ELFT> *,
std::function<void (lld:🧝:InputSectionBase<ELFT> *)>)'
being compiled with
[ ELFT=llvm::object::ELF32LE ]
llvm\tools\lld\ELF\MarkLive.cpp(136): note: see reference to function template instantiation
'void lld:🧝:markLive<llvm::object::ELF32LE>(lld:🧝:SymbolTable<llvm::object::ELF32LE> *)
being compiled
llvm-svn: 267161
I will eventually make `evaluate` function a usual parse function
rather than a function that works on a separate token list.
This is the first step toward that.
llvm-svn: 267083
You can instruct the linker to not discard sections even if they
are unused and --gc-sections option is given. The linker script
command for doing that is KEEP. The syntax is KEEP(foo) where foo
is a section name. KEEP commands are written in SECTIONS command,
so you can specify the order of sections *and* which sections
will be kept.
Each sub-command in SECTIONS command are translated into SectionRule
object. Previously, each SectionRule has `Keep` bit. However,
if you think about it, this hid information in too deep in elements
of a list. Semantically, KEEP commands aren't really related to
SECTIONS subcommands. We can keep the section list for KEEP in a
separate list. This patch does that.
llvm-svn: 267065
Since there is a copy in every translation unit that uses them, they can
be omitted from the symbol table if the address is not significant.
This still doesn't catch as many cases as the gold plugin. The
difference is that we check canBeOmittedFromSymbolTable in each file and
use lazy loading which limits what it can do. Gold checks it in the merged file.
I think the correct way of getting the same results as gold is just to
cache in the IR the result of canBeOmittedFromSymbolTable.
llvm-svn: 267063
I noticed that I was looking for the definition of SymPair when hacking
the Writer, only to find that it is just a pair of DefinedRegular symbols.
I don't think it provides more values than the cost of using brainpower
to memorize the type. I didn't roll back r266317, which introduced SymPair,
because the patch removes code repetitions. I ported that change to new
code.
llvm-svn: 267047
GNU ld and gold only support the discard-all and discard-locals with two dashes.
Retain the compatibility with the one dash spelling, but also accept the two
dashed form.
llvm-svn: 267032
`--add-needed` and `--no-add-needed` have been deprecated due to the similarity
of their spelling to `--as-needed` and `--no-as-needed`. They have been renamed
to `--copy-dt-needed-entries` and `--no-copy-dt-needed-entries`.
llvm-svn: 267031
Rafael reported on the mailing list that this reduces peak memory
usage while linking llvm-as by 15%. It makes sense to make it
the default, and introduce an inverse knob -lto-no-discard-value-names
for those who want to restore the old behavior.
llvm-svn: 267020
The gold plugin logic for common symbols is a little bit convoluted
as the plugin API has not an explicit way to update the alignment.
In gold, then, we need to keep the bitcode symbol @a around because
that's the only way to get the alignment right in the final object.
In lld, this is not true. We already have all the informations we
need about common symbols (size/alignment) so we don't have to
keep the existing symbol and pass it to the mover.
llvm-svn: 267007
SectionOrder vector was a part of LinkerScript class.
It can be removed because Commands vector contains the
same information and SectiorOrder is just a subset.
Differential revision: http://reviews.llvm.org/D19171
llvm-svn: 266974
These relocations are calculated as S + A - DTPREL or S + A - TPREL,
where DTPREL = TlsVA - 0x8000, TPREL = TlsVA - 0x7000. So the result
is relative to the TLS output section and is not an absolut value
The fix allows to escape creation of unnecessary dynamic relocations
in case of DSO linking.
llvm-svn: 266923
MIPS ABI turns using of GOT and dynamic relocations inside out. While
regular ABI uses dynamic relocations to fill up GOT entries MIPS ABI
requires dynamic linker to fills up GOT entries using specially sorted
dynamic symbol table. This affects even dynamic relocations against
symbols which do not require GOT entries creation explicitly, i.e. do
not have any GOT-relocations. So if a preemptible symbol has a dynamic
relocation we anyway have to create a GOT entry for it.
If a non-preemptible symbol has a dynamic relocation against it, dynamic
linker takes it st_value, adds offset and writes down result of the
dynamic relocation. In case of preemptible symbol dynamic linker
performs symbol resolution, writes the symbol value to the GOT entry and
reads the GOT entry when it needs to perform a dynamic relocation.
Differential Revision: http://reviews.llvm.org/D18948
llvm-svn: 266921
With the llvm change in r266919 this is the matching needed change to the lld code
now that libObject’s getName() for symbols now returning Expected<...> .
llvm-svn: 266920
Previously the function reads an operator and the rest of
the expressions. This patch makes it to actually parse an expression
which starts with a primary pexression followed by other expressions
concatenated with operators.
llvm-svn: 266912
Originally, linker scripts were basically an alternative way to specify
options to the command line options. But as we add more features to hanlde
symbols and sections, many member functions needed to be templated.
Now most the members are templated. It is probably time to template the
entire class.
Previously, LinkerScript is an executor of the linker script as well as
a storage of linker script configurations. This is not suitable to template
the class because when we are reading linker script files, we don't know
the ELF type yet, so we can't instantiate ELF-templated classes.
In this patch, I defined a new class, ScriptConfiguration, to store
linker script configurations. ScriptParser writes parse results to it,
and LinkerScript uses them.
Differential Revision: http://reviews.llvm.org/D19302
llvm-svn: 266908
It is now redundant. Writer.cpp can reason that 2 dynamic relocations
are needed: one to find the final got entry address and one to fill the
got entry.
llvm-svn: 266876
This reverts commit r266618. It breaks basically everything.
I think VS2013 doesn't interpret this code in the same way.
The size field (at least) is left uninitialized, causing all sorts of havok
(e.g. creating a 34GB file for a trivial hello world program).
The offending compiler reports itself as follows:
c:\release-vs2013>cl /?
Microsoft (R) C/C++ Optimizing Compiler Version 18.00.40629 for x64
Copyright (C) Microsoft Corporation. All rights reserved.
llvm-svn: 266857
This patch is based heavily on George Rimor's patch
http://reviews.llvm.org/D19221.
In the linker script, you can write expressions to compute addresses.
Currently we only support "+" operator. This adds a few more operators.
Since this patch adds * and /, we need to handle operator precedences
properly. I implemented that using the operator-precedence grammar.
Differential Revision: http://reviews.llvm.org/D19237
llvm-svn: 266798
Rafael Espindola