We could have add this function either Symbol or SymbolBody. I added it
to Symbol at first. But I noticed that if I've added it to SymbolBody,
we could've removed SymbolBody::setName(). So I'll do that in this patch.
llvm-svn: 306590
Summary:
In order to do this without switching on the symbol kind multiple times,
I created Defined::getChunkAndOffset and use that instead of
SymbolBody::getRVA in the inner relocation loop.
Now we get the symbol's chunk before switching over relocation types, so
we can test if it has been discarded outside the inner relocation type
switch. This also simplifies application of section relative
relocations. Previously we would switch on symbol kind to compute the
RVA, then the relocation type, and then the symbol kind again to get the
output section so we could subtract that from the symbol RVA. Now we
*always* have an OutputSection, so applying SECREL and SECTION
relocations isn't as much of a special case.
I'm still not quite happy with the cleanliness of this code. I'm not
sure what offsets and bases we should be using during the relocation
processing loop: VA, RVA, or OutputSectionOffset.
Reviewers: ruiu, pcc
Reviewed By: ruiu
Subscribers: majnemer, inglorion, llvm-commits, aprantl
Differential Revision: https://reviews.llvm.org/D34650
llvm-svn: 306566
Add support for the most common SPARC relocations.
Make DT_PLTGOT point to the PLT on SPARC.
Mark the PLT as executable on SPARC.
This adds a basic test that creates a SPARV9 executable
that invokes the exit system call on OpenBSD.
Patch by Mark Kettenis.
Differential Revision: https://reviews.llvm.org/D34618
llvm-svn: 306565
This is PR33596. Previously LLD would crash
because BYTE command synthesized output section,
but it was not assigned to Sec member of OutputSectionCommand.
Behaviour of -script and -r combination is not well defined,
but it seems after this change LLD naturally inherits behavior of
GNU linkers - creates output section requested in script and does not
crash anymore.
Differential revision: https://reviews.llvm.org/D34676
llvm-svn: 306527
This fixes PR33598.
Size field for undefined symbols is not significant.
Setting it to fixed value, like zero, may be useful though.
For example when we have 2 DSO's, like in this PR, if lower level DSO may
change slightly (in part of some symbol's st_size) and higher-level DSO is
rebuilt, then tools that monitoring checksum of high level DSO file can notice
it and trigger cascade of some other unnecessary actions.
If we set st_size to zero, that can be avoided.
Differential revision: https://reviews.llvm.org/D34673
llvm-svn: 306526
When -ffunction-sections and ARM C++ exceptions are used each .text.suffix
section will have at least one .ARM.exidx.suffix section and may have an
additional .ARM.extab.suffix section if the unwinding instructions are too
large to inline into the .ARM.exidx table entry. For a large program without
a linker script this can lead to a large number of section header table
entries that can increase the size of the ELF file.
This change introduces a default rule for .ARM.extab.* to be placed in
a single output section called .ARM.extab . This follows the behavior of
ld.gold and ld.bfd.
fixes pr33407
Differential Revision: https://reviews.llvm.org/D34678
llvm-svn: 306522
It is somewhat pointless to check that a specific error is not
produced. That is already checked by the ld.lld exit value.
Instead make the test a bit stronger by checking that the output file
has the expected symbol and section.
llvm-svn: 306496
Summary: The testing on the resource section of executables produced by lld has been very lax, and allowed a major bug to go unnoticed when we switched from shelling out to cvtres.exe to using llvm's own library. These additional tests should cover all the major failure points.
Reviewers: zturner, ruiu
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34664
llvm-svn: 306465
This patch fills holes in executable sections with 0xd4 (ARM) or
0xef (MIPS). These trap instructions were suggested by Theo de Raadt.
llvm-svn: 306322
This patch removes the dependency on the external rc.exe tool by writing
a simple .res file using our own library. In this patch I also added an
explicit definition for the .res file magic. Furthermore, I added a
unittest for embeded manifests and fixed a bug exposed by the test.
llvm-svn: 306311
Summary:
They do the obvious thing: provide the section index of .bss and the
offset of the symbol in .bss.
Reviewers: ruiu
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34628
llvm-svn: 306304
Over time we've started to add inputs and test cases using the .yaml
extension, which seems to be preferred over the .objtxt extension that
we were using initially. One nice thing about using .yaml is that it
triggers existing editor highlighting and formatting support.
Fix two pdb*.yaml test cases that I added that weren't being run as part
of check-lld.
llvm-svn: 306303
Summary:
The main change is that we can have SECREL and SECTION relocations
against ___safe_se_handler_table, which is important for handling the
debug info in the MSVCRT.
Previously we were using DefinedRelative for __safe_se_handler_table and
__ImageBase, and after we implement CFGuard, we plan to extend it to
handle __guard_fids_table, __guard_longjmp_table, and more. However,
DefinedRelative is really only suitable for implementing __ImageBase,
because it lacks a Chunk, which you need in order to figure out the
output section index and output section offset when resolving SECREl and
SECTION relocations.
This change renames DefinedRelative to DefinedSynthetic and gives it a
Chunk. One wart is that __ImageBase doesn't have a chunk. It points to
the PE header, effectively. We could split DefinedRelative and
DefinedSynthetic if we think that's cleaner and creates fewer special
cases.
I also added safeseh.s, which checks that we don't emit a safe seh table
entries pointing to garbage collected handlers and that we don't emit a
table at all when there are no handlers.
Reviewers: ruiu
Reviewed By: ruiu
Subscribers: inglorion, pcc, llvm-commits, aprantl
Differential Revision: https://reviews.llvm.org/D34577
llvm-svn: 306293
Most "reserved" symbols are in ElfSym and it looks like there's no
reason to not do the same thing for _GLOBAL_OFFSET_TABLE_. This should
help https://reviews.llvm.org/D34618 too.
llvm-svn: 306292
On many architectures gcc and clang will recognize _GLOBAL_OFFSET_TABLE_ - .
and produce a relocation that can be processed without needing to know the
value of _GLOBAL_OFFSET_TABLE_. This is not always the case; for example ARM
gcc produces R_ARM_BASE_PREL but clang produces the more general
R_ARM_REL32 to _GLOBAL_OFFSET_TABLE_. To evaluate this relocation
correctly _GLOBAL_OFFSET_TABLE_ must be defined to be the either the base of
the GOT or end of the GOT dependent on architecture..
If/when llvm-mc is changed to recognize _GLOBAL_OFFSET_TABLE_ - . this
change will not be necessary for new objects. However there may still be
old objects and versions of clang.
Differential Revision: https://reviews.llvm.org/D34355
llvm-svn: 306282
This is useful when an upper limit on the cache size needs to be
controlled independently of the amount of the amount of free space.
One use case is a machine with a large number of cache directories
(e.g. a buildbot slave hosting a large number of independent build
jobs). By imposing an upper size limit on each cache directory,
users can more easily estimate the server's capacity.
Differential Revision: https://reviews.llvm.org/D34547
llvm-svn: 306126
Summary:
For SECTION relocations against absolute symbols, MSVC emits the largest
output section index plus one. I've implemented that by threading a
global variable through DefinedAbsolute that is filled in by the Writer.
A more library-oriented approach would be to thread the Writer through
Chunk::writeTo and SectionChunk::applyRel*, but Rui seems to prefer
doing it this way.
MSVC rejects SECREL relocations against absolute symbols, but only when
the relocation is in a real output section. When the relocation is in a
CodeView debug info section destined for the PDB, it seems that this
relocation error is suppressed, and absolute symbols become zeros in the
object file. This is easily implemented by checking the input section
from which we're applying relocations.
This should fix errors about __safe_se_handler_table and
__guard_fids_table when linking the CRT and generating a PDB.
Reviewers: ruiu
Subscribers: aprantl, llvm-commits
Differential Revision: https://reviews.llvm.org/D34541
llvm-svn: 306071
Now you run llvm-pdbutil dump <options>. This is a followup
after having renamed the tool, whereas before raw was obviously
just the style of dumping, whereas now "dump" is the action to
perform with the "util".
llvm-svn: 306055
Previously, when symbol A is renamed B, both A and B end up having
the same name. This is because name is a symbol's attribute, and
we memcpy symbols for symbol renaming.
This pathc saves the original symbol name and restore it after memcpy
to keep the original name.
This patch shouldn't change program's meaning, but names in symbol
tables make more sense than before.
llvm-svn: 306036
Summary:
The main complexity in adding symbol records is that we need to
"relocate" all the type indices. Type indices do not have anything like
relocations, an opaque data structure describing where to find existing
type indices for fixups. The linker just has to "know" where the type
references are in the symbol records. I added an overload of
`discoverTypeIndices` that works on symbol records, and it seems to be
able to link the standard library.
Reviewers: zturner, ruiu
Subscribers: llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D34432
llvm-svn: 305933
This works around a strange interaction with Authenticode signatures,
in which a signed PE executable with {Major,Minor}LinkerVersion = 0.0
fails to validate on Windows 7 (but is OK on Windows 10). Setting the
linker version to 14.0 (which is what VS2015 outputs) makes it work
again.
Patch by Simon Tatham <simon.tatham@arm.com>.
llvm-svn: 305929
The --exclude-libs option is not a popular option, but at least some
programs in Android depend on it, so it's worth to support it.
Differential Revision: https://reviews.llvm.org/D34422
llvm-svn: 305920
VC2017 contains these new symbols as undefined symobls. They are used
for /guard:cf. Since we do not support the control flow guard, but we
want to at least ignore these symbols so that we can link against VS2017
libraries.
Fixes https://bugs.chromium.org/p/chromium/issues/detail?id=727193.
llvm-svn: 305876
We forgot to serialize these because llvm-readobj didn't dump them. They
are typically all zeros in an object file. The linker fills them in with
relocations before adding them to the PDB. Now we can properly round
trip these symbols through pdb2yaml -> yaml2pdb.
I made these fields optional with a zero default so that we can elide
them from our test cases.
llvm-svn: 305857
The option numbers in the macro were off by one which
leads to some confusion. There are actually 12 arguments
to this macro.
Differential Revision: https://reviews.llvm.org/D34413
llvm-svn: 305823
Summary:
Previously we didn't add debug info chunks to the SparseChunks array, so
they didn't participate in section GC. Now we do.
Reviewers: ruiu
Subscribers: aprantl, llvm-commits
Differential Revision: https://reviews.llvm.org/D34356
llvm-svn: 305811
This is patch for GSoC project, bash-completion for clang.
To use this on bash, please run `source clang/utils/bash-autocomplete.sh`.
bash-autocomplete.sh is code for bash-completion.
In this patch, Options.td was mainly changed in order to add value class
in Options.inc.
llvm-svn: 305805
I found this while trying to build u-boot. It uses -Ttext in
combination with linker scripts.
My first reaction was to change the linker scripts to have the correct
value, but I found that it is actually quite convenient to have -Ttext
take precedence.
By having just
.text : { *(.text) }
In the script, they can define the text address in a single Makefile
and pass it to ld with -Ttext and for the C code with
-DFoo=value. Doing the same with linker scripts would require them to
be generated during the build.
llvm-svn: 305766
Summary:
This is a first step towards getting line info to show up in VS and
windbg. So far, only llvm-pdbutil can parse the PDBs that we produce.
cvdump doesn't like something about our file checksum tables. I'll have
to dig into that next.
This patch adds a new DebugSubsectionRecordBuilder which takes bytes
directly from some other producer, such as a linker, and sticks it into
the PDB. Line tables only need to be relocated. No data needs to be
rewritten.
File checksums and string tables, on the other hand, need to be re-done.
Reviewers: zturner, ruiu
Subscribers: llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D34257
llvm-svn: 305713
This patch adds support for segment NONE in linker scripts which enables the
specification that a section should not be assigned to any segment.
Note that GNU ld does not disallow the definition of a segment named NONE, which
if defined, effectively overrides the behaviour described above. This feature
has been copied.
Differential Revision: https://reviews.llvm.org/D34203
llvm-svn: 305700
In r305364, Rui changed the mechanism that parses -z option values slightly.
This caused a bug, as demonstrated by this test, which now fails:
---
# REQUIRES: x86
# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
# RUN: ld.lld %t.o -o %t -z max-page-size
.global _start
_start:
nop
---
Before, the link succeeded and set the max-page-size to the target default.
After we get the following two error messages:
"invalid max-page-size: "
"max-page-size: value isn't a power of 2"
The latter error is because an uninitialised variable ends up being passed back
to getMaxPageSize).
This change ensures we only get the first error.
Reviewers: ruiu
Differential Revision: https://reviews.llvm.org/D34234
llvm-svn: 305679
The get{ARM,AArch64}UndefinedRelativeWeakVA() functions should only be
called for PC-relative relocations. Complete the supported pc-relative
relocations in the switch statement and make the default case unreachable.
The R_ARM_TARGET relocation can be evaluated as R_ARM_REL32 but it is only
used in the context of exception tables, and is never output with respect
to a weak reference so it does not appear in the switch statement.
Differential Revision: https://reviews.llvm.org/D34138
llvm-svn: 305673
In this patch, I flip the switch in DriverUtils from using the external
cvtres.exe tool to using the Windows Resource library in llvm.
I also fixed a bug where .rsrc sections were marked as discardable
memory and therefore were placed in the wrong order in the final PE.
Furthermore, I modified WindowsResource to write the coff directly to a
memory buffer instead of to file, also had it use the machine types
already declared in COFF.h instead creating my own enum.
Finally, I flipped the switch to allow all unit tests that had
previously run only on windows due to a winres dependency to run
cross-platform.
Reviewers: zturner, ruiu
Subscribers: llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D34265
llvm-svn: 305592
Summary:
Adds a "Discarded" bool to SectionChunk to indicate if the section was
discarded by COMDAT deduplication. The Writer still just checks
`isLive()`.
Fixes PR33446
Reviewers: ruiu
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34288
llvm-svn: 305582
AVR support is somewhat exotic as generated ELF executables are not
directly consumed but objcopy'ed to write it to on-chip flush memory.
This comment describes it for those why a full-fledged ELF linker is
used to link programs for the 8-bit microcontroller.
llvm-svn: 305567
Target.cpp contains code for all the targets that LLD supports. It was
simple and easy, but as the number of supported targets increased,
it got messy.
This patch splits the file into per-target files under ELF/arch directory.
Differential Revision: https://reviews.llvm.org/D34222
llvm-svn: 305565
In preparation for supporting range extension thunks we now continually
call createThunks() until no more thunks are added. This requires us to
record the thunks we add on each pass and only merge the new ones into the
OutputSection. We also need to check if a Relocation is targeting a thunk
to prevent us from infinitely creating more thunks.
Differential Revision: https://reviews.llvm.org/D34034
llvm-svn: 305555
This resubmits commit c0c249e9f2ef83e1d1e5f166b50673d92f3579d7.
It was broken due to some weird template issues, which have
since been fixed.
llvm-svn: 305517
This is probably the main patch left in unifying our intermediary
representation.
It moves the creation of default commands before section sorting. This
has the nice effect that we now have one location where we decide
where an orphan section should be placed.
Before this patch sortSections would decide the relative location of
orphan sections to other sections, but it was up to placeOrphanSection
to decide on the exact location.
We now only sort sections we created since the linker script is
already in the correct order.
llvm-svn: 305512
This reverts commit 83ea17ebf2106859a51fbc2a86031b44d33696ad.
This is failing due to some strange template problems, so reverting
until it can be straightened out.
llvm-svn: 305505
When link is invoked with `/def:` and no input files, it behaves as if
`lib.exe` was invoked. Emulate this behaviour, generating the import
library from the def file that was passed. Because there is no input to
actually generate the dll, we simply process the def file early and exit
once we have created the import library.
llvm-svn: 305502
After some internal discussions, we agreed that the raw output style had
outlived its usefulness. It was originally created before we had even
thought of dumping to YAML, and it was intended to give us some insight
into the internals of a PDB file. Now we have YAML mode which does
almost exactly this but is more powerful in that it can round-trip back
to a PDB, which the raw mode could not do. So the raw mode had become
purely a maintenance burden.
One option was to just delete it. However, its original goal was to be
as readable as possible while staying close to the "metal" - i.e.
presenting the output in a way that maps directly to the underlying file
format. We don't actually need that last requirement anymore since it's
covered by the yaml mode, so we could repurpose "raw" mode to actually
just be as readable as possible.
This patch implements about 80% of the functionality previously in raw
mode, but in a completely different style that is more akin to what
cvdump outputs. Records are very compressed, often times appearing on
just one line. One nice thing about this is that it makes full record
matching easier, because you can grep for indices, names, and leaf types
on a single line often.
See the tests for some examples of what the new output looks like.
Note that this patch actually regresses the functionality of raw mode in
a few areas, but only because the patch was already unreasonably large
and going 100% would have been even worse. Specifically, this patch is
missing:
The ability to dump module debug subsections (checksums, lines, etc)
The ability to dump section headers
Aside from that everything is here. While goign through the tests fixing
them all up, I found many duplicate tests. They've been deleted. In
subsequent patches I will go through and re-add the missing
functionality.
Differential Revision: https://reviews.llvm.org/D34191
llvm-svn: 305495
This is necessary to ensure that sections containing symbols referenced
from linker scripts (e.g. in data commands) don't get GC'd.
Differential Revision: https://reviews.llvm.org/D34195
llvm-svn: 305452
This was originally reverted because of some non-deterministic
failures on certain buildbots. Luckily ASAN eventually caught
this as a stack-use-after-scope, so the fix is included in
this patch.
llvm-svn: 305393
Summary: I found that getString defined in the LLD's Driver.cpp is
exactly the same as Arg::getLastArgValue defined in
llvm/Option/ArgLIst.h. This patch removes that local function and use
the function that the Arg class provides.
Reviewers: ruiu
Subscribers: emaste, llvm-commits
Differential Revision: https://reviews.llvm.org/D34196
llvm-svn: 305374
This is causing failures on linux bots with an invalid stream
read. It doesn't repro in any configuration on Windows, so
reverting until I have a chance to investigate on Linux.
llvm-svn: 305371
This allows us to use yaml2obj and obj2yaml to round-trip CodeView
symbol and type information without having to manually specify the bytes
of the section. This makes for much easier to maintain tests. See the
tests under lld/COFF in this patch for example. Before they just said
SectionData: <blob> whereas now we can use meaningful record
descriptions. Note that it still supports the SectionData yaml field,
which could be useful for initializing a section to invalid bytes for
testing, for example.
Differential Revision: https://reviews.llvm.org/D34127
llvm-svn: 305366
Currently we do layout as if non alloc sections had an actual address
and then set it to zero. This produces a few odd results where a
symbol has an address that is inconsistent with the section address.
The simplest way to fix it is probably to just set the address earlier.
The behavior of bfd seems to be similar, but it only sets the non
alloc section address is missing from the linker script or if the
script has an explicit " : 0" setting the address of the output
section (which the default script does).
llvm-svn: 305323
This means that 'llvm-pdbutil' in test commands will resolve
to the absolute path to the tool, in line with what happens
already for other tools.
This works either way because the bin directory is also
prepended to the PATH. I'm not sure why both methods are
used.
Differential Revision: https://reviews.llvm.org/D34128
llvm-svn: 305297
Summary:
Expose the module descriptor index and fill it in for section
contributions.
Reviewers: zturner
Subscribers: llvm-commits, ruiu, hiraditya
Differential Revision: https://reviews.llvm.org/D34126
llvm-svn: 305296
This shows an oddity of this output. While the section address is 0,
the the symbol address is computed as if the section was allocatable.
llvm-svn: 305250
The last fix required the user to manually add the required
feature. This caused an LLD test to fail because I failed to
update LLD. In practice we can hide this logic so it can just
be transparently added when we write the PDB.
llvm-svn: 305236
The ELF standard defines that the SHT_GROUP section as follows:
- its sh_link has the symbol index, and
- the symbol name is used to uniquify section groups.
Object files created by GNU gold does not seem to comply with the
standard. They have this additional rule:
- if the symbol has no name and a STT_SECTION symbol, a section
name is used instead of a symbol name.
If we don't do anything for this, the linker fails with a mysterious
error message if input files are generated by gas. It is unfortunate
but I think we need to support it.
Differential Revision: https://reviews.llvm.org/D34064
llvm-svn: 305218
Given
.weak target
.global _start
_start:
b target
The intention is that the branch goes to the instruction after the
branch, effectively turning it on a nop. The branch adds the runtime
PC, but we were adding it statically too.
I noticed the oddity by inspection, but llvm-objdump seems to agree,
since it now prints things like:
b #-4 <_start+0x4>
llvm-svn: 305212
Rafael Espindola