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
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
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
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
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
This resubmits commit c0c249e9f2ef83e1d1e5f166b50673d92f3579d7.
It was broken due to some weird template issues, which have
since been fixed.
llvm-svn: 305517
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
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
Ed Maste