This change adds experimental support for SHT_RELR sections, proposed
here: https://groups.google.com/forum/#!topic/generic-abi/bX460iggiKg
Definitions for the new ELF section type and dynamic array tags, as well
as the encoding used in the new section are all under discussion and are
subject to change. Use with caution!
Author: rahulchaudhry
Differential Revision: https://reviews.llvm.org/D47919
llvm-svn: 335922
Object FIle Representation
At codegen time this is emitted into the ELF file a pair of symbol indices and a weight. In assembly it looks like:
.cg_profile a, b, 32
.cg_profile freq, a, 11
.cg_profile freq, b, 20
When writing an ELF file these are put into a SHT_LLVM_CALL_GRAPH_PROFILE (0x6fff4c02) section as (uint32_t, uint32_t, uint64_t) tuples as (from symbol index, to symbol index, weight).
Differential Revision: https://reviews.llvm.org/D44965
llvm-svn: 333823
Previously we emitted 20-byte SHA1 hashes. This is overkill
for identifying debug info records, and has the negative side
effect of making object files bigger and links slower. By
using only the last 8 bytes of a SHA1, we get smaller object
files and ~10% faster links.
This modifies the format of the .debug$H section by adding a new
value for the hash algorithm field, so that the linker will still
work when its object files have an old format.
Differential Revision: https://reviews.llvm.org/D46855
llvm-svn: 332669
We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.
Patch produced by
for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done
Differential Revision: https://reviews.llvm.org/D46290
llvm-svn: 331272
This patch adds the ability for the ObjectYAML DWARFEmitter to calculate
the lengths of DIEs. This is accomplished by creating a DIEFixupVisitor
class which traverses the DWARF DIEs to calculate and fix up the lengths
in the Compile Unit header.
The DIEFixupVisitor can be extended in the future to enable more complex
fix ups which will enable simplified YAML string representations.
This is also very useful when using the YAML format in unit tests
because you no longer need to know the length of the compile unit when
writing the YAML string.
Differential commandeered from Chris Bieneman (beanz)
Differential revision: https://reviews.llvm.org/D30666
llvm-svn: 330421
Summary:
Original change was D43313 (r326932) and reverted by r326953 because it
broke an LLD test and a windows build. The LLD test was already fixed in
lld commit r326944 (thanks maskray). This is the original change with
the windows build fixed.
llvm-svn: 326970
This patch enhances DWARFDebugFrame with the capability of parsing and
printing DWARF expressions in CFI instructions. It also makes FDEs and
CIEs accessible to lib users, so they can process them in client tools
that rely on LLVM. To make it self-contained with a test case, it
teaches llvm-readobj to be able to dump EH frames and checks they are
correct in a unit test. The llvm-readobj code is Maksim Panchenko's work
(maksfb).
Reviewers: JDevlieghere, espindola
Reviewed By: JDevlieghere
Differential Revision: https://reviews.llvm.org/D43313
llvm-svn: 326932
Neither the linker nor the runtime need this information
anymore. We were originally using this to model BSS size
but the plan is now to use the segment metadata to allow
for BSS segments.
Differential Revision: https://reviews.llvm.org/D41366
llvm-svn: 326267
This is combination of two patches by Nicholas Wilson:
1. https://reviews.llvm.org/D41954
2. https://reviews.llvm.org/D42495
Along with a few local modifications:
- One change I made was to add the UNDEFINED bit to the binary format
to avoid the extra byte used when writing data symbols. Although this
bit is redundant for other symbols types (i.e. undefined can be
implied if a function or global is a wasm import)
- I prefer to be explicit and consistent and not have derived flags.
- Some field renaming.
- Some reverting of unrelated minor changes.
- No test output differences.
Differential Revision: https://reviews.llvm.org/D43147
llvm-svn: 325860
Introduce an extension to support passing linker options to the linker.
These would be ignored by older linkers, but newer linkers which support
this feature would be able to process the linker.
Emit a special discarded section `.linker-option`. The content of this
section is a pair of strings (key, value). The key is a type identifier for
the parameter. This allows for an argument free parameter that will be
processed by the linker with the value being the parameter. As an example,
`lib` identifies a library to be linked against, traditionally the `-l`
argument for Unix-based linkers with the parameter being the library name.
Thanks to James Henderson, Cary Coutant, Rafael Espinolda, Sean Silva
for the valuable discussion on the design of this feature.
llvm-svn: 323783
These indexes are useful because they are not always zero based and
functions and globals are referenced elsewhere by their index.
This matches what we already do for the type index space.
Differential Revision: https://reviews.llvm.org/D41877
llvm-svn: 322121
The problem was that our Obj -> Yaml dumper had not been taught
to handle certain types of records. This meant that when I
generated the test input files, the records were still there but
none of its fields were filled out. So when it did the
Yaml -> Obj conversion as part of the test, it generated records
with garbage in them.
The patch here fixes the Obj <-> Yaml converter, and additionally
updates the test file with fresh Yaml generated by the fixed
converter.
llvm-svn: 322029
This is the only wasm def (and likely likely will be
for the foreseeable) file so no need for a sub-directory
Differential Revision: https://reviews.llvm.org/D41476
llvm-svn: 321246
LLVM IR function names which disable mangling start with '\01'
(https://www.llvm.org/docs/LangRef.html#identifiers).
When an identifier like "\01@abc@" gets dumped to MIR, it is quoted, but
only with single quotes.
http://www.yaml.org/spec/1.2/spec.html#id2770814:
"The allowed character range explicitly excludes the C0 control block
allowed), the surrogate block #xD800-#xDFFF, #xFFFE, and #xFFFF."
http://www.yaml.org/spec/1.2/spec.html#id2776092:
"All non-printable characters must be escaped.
[...]
Note that escape sequences are only interpreted in double-quoted scalars."
This patch adds support for printing escaped non-printable characters
between double quotes if needed.
Should also fix PR31743.
Differential Revision: https://reviews.llvm.org/D41290
llvm-svn: 320996
Currently this is an LLVM extension to the COFF spec which is
experimental and intended to speed up linking. For now it is
behind a hidden cl::opt flag, but in the future we can move it
to a "real" cc1 flag and have the driver pass it through whenever
it is appropriate.
The patch to actually make use of this section in lld will come
in a followup.
Differential Revision: https://reviews.llvm.org/D40917
llvm-svn: 320649
The motivation behind this patch is that future directions require us to
be able to compute the hash value of records independently of actually
using them for de-duplication.
The current structure of TypeSerializer / TypeTableBuilder being a
single entry point that takes an unserialized type record, and then
hashes and de-duplicates it is not flexible enough to allow this.
At the same time, the existing TypeSerializer is already extremely
complex for this very reason -- it tries to be too many things. In
addition to serializing, hashing, and de-duplicating, ti also supports
splitting up field list records and adding continuations. All of this
functionality crammed into this one class makes it very complicated to
work with and hard to maintain.
To solve all of these problems, I've re-written everything from scratch
and split the functionality into separate pieces that can easily be
reused. The end result is that one class TypeSerializer is turned into 3
new classes SimpleTypeSerializer, ContinuationRecordBuilder, and
TypeTableBuilder, each of which in isolation is simple and
straightforward.
A quick summary of these new classes and their responsibilities are:
- SimpleTypeSerializer : Turns a non-FieldList leaf type into a series of
bytes. Does not do any hashing. Every time you call it, it will
re-serialize and return bytes again. The same instance can be re-used
over and over to avoid re-allocations, and in exchange for this
optimization the bytes returned by the serializer only live until the
caller attempts to serialize a new record.
- ContinuationRecordBuilder : Turns a FieldList-like record into a series
of fragments. Does not do any hashing. Like SimpleTypeSerializer,
returns references to privately owned bytes, so the storage is
invalidated as soon as the caller tries to re-use the instance. Works
equally well for LF_FIELDLIST as it does for LF_METHODLIST, solving a
long-standing theoretical limitation of the previous implementation.
- TypeTableBuilder : Accepts sequences of bytes that the user has already
serialized, and inserts them by de-duplicating with a hash table. For
the sake of convenience and efficiency, this class internally stores a
SimpleTypeSerializer so that it can accept unserialized records. The
same is not true of ContinuationRecordBuilder. The user is required to
create their own instance of ContinuationRecordBuilder.
Differential Revision: https://reviews.llvm.org/D40518
llvm-svn: 319198
Summary:
This change introduces a `DynamicSymbols` field to the ELF specific YAML
supported by `yaml2obj` and `obj2yaml`. This grouping of symbols provides a way
to represent ELF dynamic symbols. The `DynamicSymbols` structure is identical to
the existing `Symbols`.
Reviewers: compnerd, jakehehrlich, silvas
Reviewed By: silvas
Subscribers: silvas, jakehehrlich, llvm-commits
Differential Revision: https://reviews.llvm.org/D39582
llvm-svn: 318433
Summary:
This change allows yaml input to control the order of implicitly added sections
(`.symtab`, `.strtab`, `.shstrtab`). The order is controlled by adding a
placeholder section of the given name to the Sections field.
This change is to support changes in D39582, where it is desirable to control
the location of the `.dynsym` section.
This reapplied version fixes:
1. use of a function call within an assert
2. failing lld test which has an unnamed section
3. incorrect section count when given an unnamed section
Additionally, one more test to cover the unnamed section failure.
Reviewers: compnerd, jakehehrlich
Reviewed By: jakehehrlich
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D39749
llvm-svn: 317789
Summary:
This change allows yaml input to control the order of implicitly added sections
(`.symtab`, `.strtab`, `.shstrtab`). The order is controlled by adding a
placeholder section of the given name to the Sections field.
This change is to support changes in D39582, where it is desirable to control
the location of the `.dynsym` section.
This reapplied version fixes:
1. use of a function call within an assert
2. failing lld test which has an unnamed section
Additionally, one more test to cover the unnamed section failure.
Reviewers: compnerd, jakehehrlich
Reviewed By: jakehehrlich
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D39749
llvm-svn: 317646
Summary:
This change allows yaml input to control the order of implicitly added sections
(`.symtab`, `.strtab`, `.shstrtab`). The order is controlled by adding a
placeholder section of the given name to the Sections field.
This change is to support changes in D39582, where it is desirable to control
the location of the `.dynsym` section.
Reviewers: compnerd, jakehehrlich
Reviewed By: jakehehrlich
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D39749
llvm-svn: 317622
Sometimes program headers have larger alignments than any of the
sections they contain. Currently yaml2obj can't produce such files. A
bug recently appeared in llvm-objcopy that failed in such a case. I'd
like to be able to add tests to llvm-objcopy for such cases.
This change adds an optional alignment parameter to program headers that
will be used instead of calculating the alignment.
Differential Revision: https://reviews.llvm.org/D39130
llvm-svn: 317139
This is in preparation for testing lld's upcoming relocation packing
feature (D39152). I have verified that this implementation correctly
unpacks the relocations from a Chromium DSO built with gold and the
Android relocation packer for ARM32 and ARM64.
Differential Revision: https://reviews.llvm.org/D39272
llvm-svn: 316543
This was previously being silently dropped by obj2yaml and caused
parsing errors with yaml2obj.
Differential Revision: https://reviews.llvm.org/D38490
llvm-svn: 314768
Add adds support for naming data segments. This is useful
useful linkers so that they can merge similar sections.
Differential Revision: https://reviews.llvm.org/D37886
llvm-svn: 313795
Alexandre Ganea