The ARMDisassembler changes allow changing between ARM and Thumb mode
based on the MCSubtargetInfo, rather than the Target, which simplifies
the other changes a bit.
I'm not really happy with adding more target-specific logic to
tools/llvm-objdump/, but there isn't any easy way around it: the logic
in question specifically applies to disassembling an object file, and
that code simply isn't located in lib/Target, at least at the moment.
Differential Revision: https://reviews.llvm.org/D60927
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@363903 91177308-0d34-0410-b5e6-96231b3b80d8
r363016 let lld-link and llvm-lib share the /machine: parsing code.
This lets llvm-cvtres share it as well.
Making llvm-cvtres depend on llvm-lib seemed a bit strange (it doesn't
need llvm-lib's dependencies on BinaryFormat and BitReader) and I
couldn't find a good place to put this code. Since it's just a few
lines, put it in lib/Object for now.
Differential Revision: https://reviews.llvm.org/D63120
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@363144 91177308-0d34-0410-b5e6-96231b3b80d8
For lld, pass in Config->Timestamp (which is set based on lld's
/timestamp: and /Brepro flags). Since the writeWindowsResourceCOFF()
data is only used in-memory by LLD and the obj's timestamp isn't used
for anything in the output, this doesn't change behavior.
For llvm-cvtres, add an optional /timestamp: parameter, and use the
current behavior of calling time() if the parameter is not passed in.
This doesn't really change observable behavior (unless someone passes
/timestamp: to llvm-cvtres, which wasn't possible before), but it
removes the last unqualified call to time() from llvm/lib, which seems
like a good thing.
Differential Revision: https://reviews.llvm.org/D63116
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@363050 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
When handling exports from the command line or from .def files, the
linker does a "fuzzy" string lookup to allow finding mangled symbols.
However, when the symbol is re-exported under a new name, the linker has
to transfer the decorations from the exported symbol over to the new
name. This is implemented by taking the mangled symbol that was found in
the object and replacing the original symbol name with the export name.
Before this patch, LLD implemented the fuzzy search by adding an
undefined symbol with the unmangled name, and then during symbol
resolution, checking if similar mangled symbols had been added after the
last round of symbol resolution. If so, LLD makes the original symbol a
weak alias of the mangled symbol. Later, to get the original symbol
name, LLD would look through the weak alias and forward it on to the
import library writer, which copies the symbol decorations. This
approach doesn't work when bar is itself a weak alias, as is the case in
asan. It's especially bad when the aliasee of bar contains the string
"bar", consider "bar_default". In this case, we would end up exporting
the symbol "foo_default" when we should've exported just "foo".
To fix this, don't look through weak aliases to find the mangled name.
Save the mangled name earlier during fuzzy symbol lookup.
Fixes PR42074
Reviewers: mstorsjo, ruiu
Subscribers: thakis, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62984
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@362849 91177308-0d34-0410-b5e6-96231b3b80d8
Includes a fix for an introduced build failure due to a post c++11 use of std::mismatch.
This fixes some thin archive relative path issues, paths are shortened where possible and paths are output correctly when using the display table command.
Differential Revision: https://reviews.llvm.org/D59491
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@362484 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r362407. It broke compilation of
llvm/lib/Object/ArchiveWriter.cpp:
error: type 'llvm::sys::path::const_iterator' does not provide a call
operator
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@362413 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This patch implement parsing symbol table for xcoffobjfile and
output as yaml format. Parsing auxiliary entries of a symbol
will be in a separate patch.
The XCOFF object file (aix_xcoff.o) used in the test comes from
-bash-4.2$ cat test.c
extern int i;
extern int TestforXcoff;
int main()
{
i++;
TestforXcoff--;
}
Patch by DiggerLin
Reviewers: sfertile, hubert.reinterpretcast, MaskRay, daltenty
Differential Revision: https://reviews.llvm.org/D61532
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@361832 91177308-0d34-0410-b5e6-96231b3b80d8
For clients iterating the symbol table, none expects to handle index 0
(STN_UNDEF). Skip it to improve consistency with other binary formats.
Clients that need STN_UNDEF (e.g. lld) can use
getSectionContentsAsArray(). A test will be added in D62148.
Reviewed By: mtrent
Differential Revision: https://reviews.llvm.org/D62296
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@361506 91177308-0d34-0410-b5e6-96231b3b80d8
This patch implements a limited form of autolinking primarily designed to allow
either the --dependent-library compiler option, or "comment lib" pragmas (
https://docs.microsoft.com/en-us/cpp/preprocessor/comment-c-cpp?view=vs-2017) in
C/C++ e.g. #pragma comment(lib, "foo"), to cause an ELF linker to automatically
add the specified library to the link when processing the input file generated
by the compiler.
Currently this extension is unique to LLVM and LLD. However, care has been taken
to design this feature so that it could be supported by other ELF linkers.
The design goals were to provide:
- A simple linking model for developers to reason about.
- The ability to to override autolinking from the linker command line.
- Source code compatibility, where possible, with "comment lib" pragmas in other
environments (MSVC in particular).
Dependent library support is implemented differently for ELF platforms than on
the other platforms. Primarily this difference is that on ELF we pass the
dependent library specifiers directly to the linker without manipulating them.
This is in contrast to other platforms where they are mapped to a specific
linker option by the compiler. This difference is a result of the greater
variety of ELF linkers and the fact that ELF linkers tend to handle libraries in
a more complicated fashion than on other platforms. This forces us to defer
handling the specifiers to the linker.
In order to achieve a level of source code compatibility with other platforms
we have restricted this feature to work with libraries that meet the following
"reasonable" requirements:
1. There are no competing defined symbols in a given set of libraries, or
if they exist, the program owner doesn't care which is linked to their
program.
2. There may be circular dependencies between libraries.
The binary representation is a mergeable string section (SHF_MERGE,
SHF_STRINGS), called .deplibs, with custom type SHT_LLVM_DEPENDENT_LIBRARIES
(0x6fff4c04). The compiler forms this section by concatenating the arguments of
the "comment lib" pragmas and --dependent-library options in the order they are
encountered. Partial (-r, -Ur) links are handled by concatenating .deplibs
sections with the normal mergeable string section rules. As an example, #pragma
comment(lib, "foo") would result in:
.section ".deplibs","MS",@llvm_dependent_libraries,1
.asciz "foo"
For LTO, equivalent information to the contents of a the .deplibs section can be
retrieved by the LLD for bitcode input files.
LLD processes the dependent library specifiers in the following way:
1. Dependent libraries which are found from the specifiers in .deplibs sections
of relocatable object files are added when the linker decides to include that
file (which could itself be in a library) in the link. Dependent libraries
behave as if they were appended to the command line after all other options. As
a consequence the set of dependent libraries are searched last to resolve
symbols.
2. It is an error if a file cannot be found for a given specifier.
3. Any command line options in effect at the end of the command line parsing apply
to the dependent libraries, e.g. --whole-archive.
4. The linker tries to add a library or relocatable object file from each of the
strings in a .deplibs section by; first, handling the string as if it was
specified on the command line; second, by looking for the string in each of the
library search paths in turn; third, by looking for a lib<string>.a or
lib<string>.so (depending on the current mode of the linker) in each of the
library search paths.
5. A new command line option --no-dependent-libraries tells LLD to ignore the
dependent libraries.
Rationale for the above points:
1. Adding the dependent libraries last makes the process simple to understand
from a developers perspective. All linkers are able to implement this scheme.
2. Error-ing for libraries that are not found seems like better behavior than
failing the link during symbol resolution.
3. It seems useful for the user to be able to apply command line options which
will affect all of the dependent libraries. There is a potential problem of
surprise for developers, who might not realize that these options would apply
to these "invisible" input files; however, despite the potential for surprise,
this is easy for developers to reason about and gives developers the control
that they may require.
4. This algorithm takes into account all of the different ways that ELF linkers
find input files. The different search methods are tried by the linker in most
obvious to least obvious order.
5. I considered adding finer grained control over which dependent libraries were
ignored (e.g. MSVC has /nodefaultlib:<library>); however, I concluded that this
is not necessary: if finer control is required developers can fall back to using
the command line directly.
RFC thread: http://lists.llvm.org/pipermail/llvm-dev/2019-March/131004.html.
Differential Revision: https://reviews.llvm.org/D60274
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@360984 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
the stream format is exactly the same as for ThreadList and ModuleList
streams, only the entry types are slightly different, so the changes in
this patch are just straight-forward applications of established
patterns.
Reviewers: amccarth, jhenderson, clayborg
Subscribers: markmentovai, lldb-commits, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61885
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@360908 91177308-0d34-0410-b5e6-96231b3b80d8
r360876 didn't fix 2 call sites in clang.
Expected<ArrayRef<uint8_t>> may be better but use Expected<StringRef> for now.
Follow-up of D61781.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@360892 91177308-0d34-0410-b5e6-96231b3b80d8
It broke the Clang build, see llvm-commits thread.
> Expected<ArrayRef<uint8_t>> may be better but use Expected<StringRef> for now.
>
> Follow-up of D61781.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@360878 91177308-0d34-0410-b5e6-96231b3b80d8
Change
std::error_code getSectionContents(DataRefImpl, StringRef &) const;
to
Expected<ArrayRef<uint8_t>> getSectionContents(DataRefImpl) const;
Many object formats use ArrayRef<uint8_t> as the underlying type, which
is generally better than StringRef to represent binary data, so change
the type to decrease the number of type conversions.
Reviewed By: ruiu, sbc100
Differential Revision: https://reviews.llvm.org/D61781
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@360648 91177308-0d34-0410-b5e6-96231b3b80d8
This fixes the https://bugs.llvm.org/show_bug.cgi?id=41355.
Previously with -r we printed relocation section name instead of the target section name.
It was like this: "RELOCATION RECORDS FOR [.rel.text]"
Now it is: "RELOCATION RECORDS FOR [.text]"
Also when relocation target section has more than one relocation section,
we did not combine the output. Now we do.
Differential revision: https://reviews.llvm.org/D61312
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@360143 91177308-0d34-0410-b5e6-96231b3b80d8
Patch adds support for dumping of file headers with llvm-readobj. XCOFF
object files are added to test dumping a well formed file, and dumping
both negative timestamps and negative symbol counts, both of which are
allowed in the XCOFF definition.
Differential Revision: https://reviews.llvm.org/D60878
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@359878 91177308-0d34-0410-b5e6-96231b3b80d8
As a side benefit, lld-link now reports more than one duplicate resource
entry before exiting with an error even if the new flag is not passed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@359829 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
The stream contains the list of threads belonging to the process
described by the minidump. Its structure is the same as the ModuleList
stream, and in fact, I have generalized the ModuleList reading code to
handle this stream too.
Reviewers: amccarth, jhenderson, clayborg
Subscribers: llvm-commits, lldb-commits, markmentovai, zturner
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61064
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@359762 91177308-0d34-0410-b5e6-96231b3b80d8
Reduces the error message from:
lld-link: error: failed to parse .res file: duplicate resource: type STRINGTABLE (ID 6)/name ID 3/language 1033, in test1.res and in test2.res
To:
lld-link: error: duplicate resource: type STRINGTABLE (ID 6)/name ID 3/language 1033, in test1.res and in test2.res
Make sure every error message emitted by cvtres contains the name of at
least one ".res" file, so that removing the "failed to parse .res file"
string doesn't lose information.
Differential Revision: https://reviews.llvm.org/D61388
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@359749 91177308-0d34-0410-b5e6-96231b3b80d8
For well-known type IDs, include the name of the type.
To not duplicate the ID->name map, make llvm-readobj call this new
function as well. It has slightly different output, so this also
requires updating a few tests.
Differential Revision: https://reviews.llvm.org/D61086
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@359153 91177308-0d34-0410-b5e6-96231b3b80d8
If two .res files contain the same resource, cvtres.exe (and hence
link.exe) reject the input with this message:
CVTRES : fatal error CVT1100: duplicate resource. type:STRING, name:101, language:0x0409
LINK : fatal error LNK1123: failure during conversion to COFF: file invalid or corrupt
llvm-cvtres (and lld-link) used to silently pick one of the duplicate
resources instead. This patch makes them report an error as well.
We slightly improve on cvtres by printing the name of two .res files
containing duplicate entries as well.
Differential Revision: https://reviews.llvm.org/D61049
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@359083 91177308-0d34-0410-b5e6-96231b3b80d8
Before, there was an IsData parameter. Now, there are two different
functions for data nodes and ID nodes. No behavior change, needed for a
follow-up change to make two data nodes (but not two ID nodes) with the
same ID an error.
For consistency, rename another addChild() overload to addNameChild().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@359024 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This patch adds support for yaml (de)serialization of the minidump
ModuleList stream. It's a fairly straight forward-application of the
existing patterns to the ModuleList structures defined in previous
patches.
One thing, which may be interesting to call out explicitly is the
addition of "new" allocation functions to the helper BlobAllocator
class. The reason for this was, that there was an emerging pattern of a
need to allocate space for entities, which do not have a suitable
lifetime for use with the existing allocation functions. A typical
example of that was the "size" of various lists, which is only available
as a temporary returned by the .size() method of some container. For
these cases, one can use the new set of allocation functions, which
will take a temporary object, and store it in an allocator-managed
buffer until it is written to disk.
Reviewers: amccarth, jhenderson, clayborg, zturner
Subscribers: lldb-commits, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60405
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358672 91177308-0d34-0410-b5e6-96231b3b80d8
This updates the StackMap parser in the llvm-readobj tool to parse version 3 StackMaps, which were bumped in https://reviews.llvm.org/D32629.
Version 3 StackMaps differ in that they have a uint16 sized "location size" field which was added to the Location block in a StackMap record. The record has additional padding for alignment. This was a backwards incompatible change resulting in a StackMap version bump.
Patch By: jacob.hughes@kcl.ac.uk (with a rewrite of tests by me)
Differential Revision: https://reviews.llvm.org/D59020
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358325 91177308-0d34-0410-b5e6-96231b3b80d8
The size field of a location can be different for each entry, so it is useful to have this displayed in the output of llvm-readobj -stackmap. Below is an example of how the output would look:
Record ID: 2882400000, instruction offset: 16
3 locations:
#1: Constant 1, size: 8
#2: Constant 2, size: 8
#3: Constant 3, size: 8
0 live-outs: [ ]
Patch By: jacob.hughes@kcl.ac.uk (with heavy modification by me)
Differential Revision: https://reviews.llvm.org/D59169
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358324 91177308-0d34-0410-b5e6-96231b3b80d8
Motivation is to reduce silly diffs when we change the format. For instance, this causes most of D59020 to disappear.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358322 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This ensures that object files will continue to validate as
WebAssembly modules in the presence of bulk memory operations. Engines
that don't support bulk memory operations will not recognize the
DataCount section and will report validation errors, but that's ok
because object files aren't supposed to be run directly anyway.
Reviewers: aheejin, dschuff, sbc100
Subscribers: jgravelle-google, hiraditya, sunfish, rupprecht, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60623
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358315 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
The ModuleList stream consists of an integer giving the number of
entries in the list, followed by the list itself. Each entry in the list
describes a module (dynamically loaded objects which were loaded in the
process when it crashed (or when the minidump was generated).
The code for reading the list is relatively straight-forward, with a
single gotcha. Some minidump writers are emitting padding after the
"count" field in order to align the subsequent list on 8 byte boundary
(this depends on how their ModuleList type was defined and the native
alignment of various types on their platform). Fortunately, the minidump
format contains enough redundancy (in the form of the stream length
field in the stream directory), which allows us to detect this situation
and correct it.
This patch just adds the ability to parse the stream. Code for
conversion to/from yaml will come in a follow-up patch.
Reviewers: zturner, amccarth, jhenderson, clayborg
Subscribers: jdoerfert, markmentovai, lldb-commits, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60121
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357897 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Provides a new type, `LLVMBinaryRef`, and a binding to `llvm::object::createBinary` for more general interoperation with binary files than `LLVMObjectFileRef`. It also provides the proper non-consuming API for input buffers and populates an out parameter for error handling if necessary - two things the previous API did not do.
In a follow-up, I'll define section and symbol iterators and begin to build upon the existing test infrastructure.
This patch is a first step towards deprecating that API and replacing it with something more robust.
Reviewers: deadalnix, whitequark
Reviewed By: whitequark
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60322
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357822 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Strings in minidump files are stored as a 32-bit length field, giving
the length of the string in *bytes*, which is followed by the
appropriate number of UTF16 code units. The string is also supposed to
be null-terminated, and the null-terminator is not a part of the length
field. This patch:
- adds support for reading these strings out of the minidump file (this
implementation does not depend on proper null-termination)
- adds support for writing them to a minidump file
- using the previous two pieces implements proper (de)serialization of
the CSDVersion field of the SystemInfo stream. Previously, this was
only read/written as hex, and no attempt was made to access the
referenced string -- now this string is read and written correctly.
The changes are tested via yaml2obj|obj2yaml round-trip as well as a
unit test which checks the corner cases of the string deserialization
logic.
Reviewers: jhenderson, zturner, clayborg
Subscribers: llvm-commits, aprantl, markmentovai, amccarth, lldb-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59775
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357749 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
getRelocatedValue may compute incorrect value for SHT_RELA-typed relocation entries.
// DWARFDataExtractor.cpp
uint64_t DWARFDataExtractor::getRelocatedValue(uint32_t Size, uint32_t *Off,
...
// This formula is correct for REL, but may be incorrect for RELA if the value
// stored in the location (getUnsigned(Off, Size)) is not zero.
return getUnsigned(Off, Size) + Rel->Value;
In this patch, we
* refactor these visit* functions to include a new parameter `uint64_t A`.
Since these visit* functions are no longer used as visitors, rename them to resolve*.
+ REL: A is used as the addend. A is the value stored in the location where the
relocation applies: getUnsigned(Off, Size)
+ RELA: The addend encoded in RelocationRef is used, e.g. getELFAddend(R)
* and add another set of supports* functions to check if a given relocation type is handled.
DWARFObjInMemory uses them to fail early.
Reviewers: echristo, dblaikie
Reviewed By: echristo
Subscribers: mgorny, aprantl, aheejin, fedor.sergeev, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D57939
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356729 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This patch adds basic support for reading minidump files. It contains
the definitions of various important minidump data structures (header,
stream directory), and of one minidump stream (SystemInfo). The ability
to read other streams will be added in follow-up patches. However, all
streams can be read even now as raw data, which means lldb's minidump
support (where this code is taken from) can be immediately rebased on
top of this patch as soon as it lands.
As we don't have any support for generating minidump files (yet), this
tests the code via unit tests with some small handcrafted binaries in
the form of c char arrays.
Reviewers: Bigcheese, jhenderson, zturner
Subscribers: srhines, dschuff, mgorny, fedor.sergeev, lemo, clayborg, JDevlieghere, aprantl, lldb-commits, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59291
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356652 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
llvm-objdump (via libObject) validates DYLD_INFO rebase and bind
entries against the basic structure found in the Mach-O file before
evaluating the contents of those entries. Certain malformed Mach-Os can
defeat the validation check and force llvm-objdump (libObject) to crash.
The previous logic verified a rebase or bind started in a valid Mach-O
section, but did not verify that the section wholely contained the
fixup. It also generally allows rebases or binds to start immediately
after a valid section even if that range is not itself part of a valid
section. Finally, bind and rebase opcodes that indicate more than one
fixup (apply N times...) are not completely validated: only the first
and final fixups are checked.
The previous logic also rejected certain binaries as false positives.
Some bind and rebase opcodes can modify the state machine such that the
next bind or rebase will fail. libObject will reject these opcodes as
invalid in order to be helpful and print an error message associated
with the instruction that caused the problem, even though the binary is
not actually illegal until it consumes the invalid state in the state
machine. In other words, libObject may reject a Mach-O binary that
Apple's dynamic linker may consider legal. The original version of
macho-rebase-add-addr-uleb-too-big is an example of such a binary.
I have replaced the existing checkSegAndOffset and checkCountAndSkip
functions with a single function, checkSegAndOffsets, which validates
all of the fixups realized by a DYLD_INFO opcode. checkSegAndOffsets
verifies that a Mach-O section fully contains each fixup. Every fixup
realized by an opcode is validated, and some (but not all!)
inconsistencies in the state machine are allowed until a fixup is
realized. This means that libObject may fail on an opcode that realizes
a fixup, not on the opcode that introduced the arithmetic error.
Existing test cases have been modified to reflect the changes in error
messages returned by libObject. What's more, the test case for
macho-rebase-add-addr-uleb-too-big has been modified so that it actually
triggers the error condition; the new code in libObject considers the
original test binary "legal".
rdar://47797757
Reviewers: lhames, pete, ab
Reviewed By: pete
Subscribers: rupprecht, jdoerfert, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59574
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356629 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Implements a new target features section in assembly and object files
that records what features are used, required, and disallowed in
WebAssembly objects. The linker uses this information to ensure that
all objects participating in a link are feature-compatible and records
the set of used features in the output binary for use by optimizers
and other tools later in the toolchain.
The "atomics" feature is always required or disallowed to prevent
linking code with stripped atomics into multithreaded binaries. Other
features are marked used if they are enabled globally or on any
function in a module.
Future CLs will add linker flags for ignoring feature compatibility
checks and for specifying the set of allowed features, implement using
the presence of the "atomics" feature to control the type of memory
and segments in the linked binary, and add front-end flags for
relaxing the linkage policy for atomics.
Reviewers: aheejin, sbc100, dschuff
Subscribers: jgravelle-google, hiraditya, sunfish, mgrang, jfb, jdoerfert, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59173
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356610 91177308-0d34-0410-b5e6-96231b3b80d8
That patch is the fix for https://bugs.llvm.org/show_bug.cgi?id=40703
"wrong line number info for obj file compiled with -ffunction-sections"
bug. The problem happened with only .o files. If object file contains
several .text sections then line number information showed incorrectly.
The reason for this is that DwarfLineTable could not detect section which
corresponds to specified address(because address is the local to the
section). And as the result it could not select proper sequence in the
line table. The fix is to pass SectionIndex with the address. So that it
would be possible to differentiate addresses from various sections. With
this fix llvm-objdump shows correct line numbers for disassembled code.
Differential review: https://reviews.llvm.org/D58194
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354972 91177308-0d34-0410-b5e6-96231b3b80d8
