This patch adds a way for users to create their own custom sections to
be added to wasm files. At the LLVM IR layer, they are defined through
the "wasm.custom_sections" named metadata. The expected use case for
this is bindings generators such as wasm-bindgen.
Patch by Dan Gohman
Differential Revision: https://reviews.llvm.org/D45297
llvm-svn: 329315
This is required in order to enable relocs to be validated
as they are read in.
Also update tests with new section ordering.
Differential Revision: https://reviews.llvm.org/D43940
llvm-svn: 326694
The original BinaryEncoding.md document used to specify that
these values were `varint7`, but the official spec lists them
explicitly as single byte values and not LEB.
A similar change for wabt is in flight:
https://github.com/WebAssembly/wabt/pull/782
Differential Revision: https://reviews.llvm.org/D43921
llvm-svn: 326454
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
Add an explicit check before looking up symbol in SymbolIndices.
This was previously silently succeeding and returning zero for such
unnamed temporaries.
Differential Revision: https://reviews.llvm.org/D43365
llvm-svn: 325367
For now, we are not using wasm globals, except for modeling of
the stack points.
Alos, factor out common struct WasmGlobalType, which matches the
name for that tuple in the Wasm spec and rename methods
to "isBindingGlobal", "isTypeGlobal" to avoid ambiguity.
Patch by Nicholas Wilson!
Differential Revision: https://reviews.llvm.org/D42750
llvm-svn: 323901
This change is useful for the upcoming addition of the symbol
table (D41954) since in that world aliases for given function
all share the same function index.
This change does not effect lld because it essentially ignores
the wasm "table". The table exists only to the wasm objects
will validate and disassembly meaningfully.
Patch by Nicholas Wilson!
Differential Revision: https://reviews.llvm.org/D42095
llvm-svn: 323900
Relocations of type R_WEBASSEMBLY_TABLE_INDEX represent places
where the table index for a given function is needed. While the
value stored in this location is a table index, the index in
the relocation entry itself is a function index (the index of
the function which is to be called indirectly).
This is how is was spec'd originally but the LLVM implementation
didn't do this. This makes things a little simpler in the linker
since the table in the input file can essentially be ignored that
the output table can be created purely based on these relocations.
Patch by Nicholas Wilson!
Differential Revision: https://reviews.llvm.org/D42080
llvm-svn: 323165
Summary:
For consistency with the output of lld.
This is useful in runnable binaries as can them be sure the
null function pointer will never be a valid argument
call_indirect.
Subscribers: jfb, dschuff, jgravelle-google, aheejin, sunfish, llvm-commits
Differential Revision: https://reviews.llvm.org/D42284
llvm-svn: 322978
Get rid of DEBUG_FUNCTION_NAME symbols. When we actually debug
data, maybe we'll want somewhere to put it... but having a symbol
that just stores the name of another symbol seems odd.
It means you have multiple Symbols with the same name, one
containing the actual function and another containing the name!
Store the names in a vector on the WasmObjectFile when reading
them in. Also stash them on the WasmFunctions themselves.
The names are //not// "symbol names" or aliases or anything,
they're just the name that a debugger should show against the
function body itself. NB. The WasmObjectFile stores them so that
they can be exported in the YAML losslessly, and hence the tests
can be precise.
Enforce that the CODE section has been read in before reading
the "names" section. Requires minor adjustment to some tests.
Patch by Nicholas Wilson!
Differential Revision: https://reviews.llvm.org/D42075
llvm-svn: 322741
Summary:
This argument (the isUsed flag) seems to only be relevant
when parsing. Other calls sites such as these don't seem
to ever use it.
Subscribers: jfb, dschuff, jgravelle-google, aheejin, sunfish
Differential Revision: https://reviews.llvm.org/D41970
llvm-svn: 322332
This is more in line with what happens in the final
executable when symbols are undefined (i.e. weak
references).
Differential Revision: https://reviews.llvm.org/D41840
llvm-svn: 322130
Previously, taking the address for an alias would result in:
"Symbol not found in table index space"
Increase test coverage for weak aliases.
This code should be more efficient too as it avoids building
the `IsAddressTaken` set.
Differential Revision: https://reviews.llvm.org/D41510
llvm-svn: 321384
When weak aliases are used with in same translation
unit we need to be able to directly reference to alias
and not just the thing it is aliases. We do this by
defining both a wasm import and a wasm export in this
case that result in a single Symbol. This change is
a partial revert of rL314245. A corresponding lld
change address the previous issues we had with this.
See: https://github.com/WebAssembly/tool-conventions/issues/34
Differential Revision: https://reviews.llvm.org/D41472
llvm-svn: 321242
Summary:
- lowers @llvm.global_dtors by adding @llvm.global_ctors
functions which register the destructors with `__cxa_atexit`.
- impements @llvm.global_ctors with wasm start functions and linker metadata
See [here](https://github.com/WebAssembly/tool-conventions/issues/25) for more background.
Subscribers: jfb, dschuff, mgorny, jgravelle-google, aheejin, sunfish
Differential Revision: https://reviews.llvm.org/D41211
llvm-svn: 320774
Instead of having .o files contain linear-memory and function table
definitions, use imports. This is more consistent with the stack pointer
being imported, and it's consistent with the linker being the one to
decide whether linear memory and function table are imported or defined
in the linked output. This implements tool-conventions #23.
Differential Revision: https://reviews.llvm.org/D40875
llvm-svn: 319989
This is not currently valid by the wasm spec, however:
- It replaces doing set_global on an immutable global, which is also
not valid.
- It's expected be valid in the near future:
https://github.com/WebAssembly/threads/blob/master/proposals/threads/Globals.md
- This only occurs before linking, so a fully linked object will be
valid.
llvm-svn: 319810
Original change was rL319488.
This was reverted rL319602 due to a gcc 7.1 warning.
Differential Revision: https://reviews.llvm.org/D40772
llvm-svn: 319626
The LLVM "hidden" flag needs to be passed through the Wasm
intermediate objects in order for the linker to apply
it to the final Wasm object.
The corresponding change in LLD is here: https://github.com/WebAssembly/lld/pull/14
Patch by Nicholas Wilson
Differential Revision: https://reviews.llvm.org/D40442
llvm-svn: 319488
Generalize FixFunctionBitcasts to handle varargs functions. This in
particular fixes the case where clang bitcasts away a varargs when
calling a K&R-style function.
This avoids interacting with tricky ABI details because it operates
at the LLVM IR level before varargs ABI details are exposed.
This fixes PR35385.
llvm-svn: 319186
This ensures that each segment has a unique address.
Without this, consecutive zero sized symbols would
end up with the same address and the linker cannot
map symbols to unique data segments.
Differential Revision: https://reviews.llvm.org/D39107
llvm-svn: 316717
Summary:
Add LLVM_FORCE_ENABLE_DUMP cmake option, and use it along with
LLVM_ENABLE_ASSERTIONS to set LLVM_ENABLE_DUMP.
Remove NDEBUG and only use LLVM_ENABLE_DUMP to enable dump methods.
Move definition of LLVM_ENABLE_DUMP from config.h to llvm-config.h so
it'll be picked up by public headers.
Differential Revision: https://reviews.llvm.org/D38406
llvm-svn: 315590
functions.
This makes the ownership of the resulting MCObjectWriter clear, and allows us
to remove one instance of MCObjectStreamer's bizarre "holding ownership via
someone else's reference" trick.
llvm-svn: 315327
to WasmObjectWriter's constructor.
Fixes the same ownership issue for COFF that r315245 did for MachO:
WasmObjectWriter takes ownership of its MCWasmObjectTargetWriter, so we want to
pass this through to the constructor via a unique_ptr, rather than a raw ptr.
llvm-svn: 315260
Previously these were being included as both imports and
exports, with the import being satisfied by the export
(or some strong symbol) at runtime. However proved
unnecessary and actually complicated linking as it meant
there was not a 1-to-1 mapping between a wasm function
/global index and a linker symbol.
Differential Revision: https://reviews.llvm.org/D38246
llvm-svn: 314245
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
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: 313692
This means that we can honor -fdata-sections rather than
always creating a segment for each symbol.
It also allows for a followup change to add .init_array and friends.
Differential Revision: https://reviews.llvm.org/D37876
llvm-svn: 313395
Previously the 'Padding' argument was the number of padding
bytes to add. However most callers that use 'Padding' know
how many overall bytes they need to write. With the previous
code this would mean encoding the LEB once to find out how
many bytes it would occupy and then using this to calulate
the 'Padding' value.
See: https://reviews.llvm.org/D36595
Differential Revision: https://reviews.llvm.org/D37494
llvm-svn: 313393
- Create helper function for resolving weak references.
- Add test that preproduces the crash.
Differential Revision: https://reviews.llvm.org/D37916
llvm-svn: 313381
This is stepping stone towards honoring -fdata-sections
and letting the assembler decide how many wasm data
segments to create.
Differential Revision: https://reviews.llvm.org/D37834
llvm-svn: 313313
Summary: When implementing MCFillFragment, use the size of the fragment,
rather than the size of the section.
Patch by Dan Gohman
Differential Revision: https://reviews.llvm.org/D35090
llvm-svn: 307565
Model weakly defined symbols as symbols that are both
exports and imported and marked as weak. Local references
to the symbols refer to the import but the linker can
resolve this to the weak export if not strong symbol
is found at link time.
Differential Revision: https://reviews.llvm.org/D35029
llvm-svn: 307348
Previously we were generating a void(void) function type
for a weak alias. Update the weak-alias test case to
catch this.
Differential Revision: https://reviews.llvm.org/D34734
llvm-svn: 307194
The overal size of the data section (including BSS)
is otherwise not included in the wasm binary.
Differential Revision: https://reviews.llvm.org/D34657
llvm-svn: 306459
- Use auto where appropriate
- Use early return to reduce nesting
- Remove stray comment line
- Use C++ foreach over explicit iterator
Differential Revision: https://reviews.llvm.org/D34477
llvm-svn: 305971
The lld-x86_64-darwin13 is failing with:
error: unused function 'operator<<'
Wrap the declation in ifndef NDEBUG, which matches
what is done in MipsELFObjectWriter.cpp.
Differential Revision: https://reviews.llvm.org/D34384
llvm-svn: 305771
This fixes two build failures that only occur in certain
configurations:
- error: unused function 'operator<<'
- error: control reaches end of non-void function
Differential Revision: https://reviews.llvm.org/D34382
llvm-svn: 305770
This ensures that symbolic relocations are generated for stack
pointer manipulations.
These relocations are of type R_WEBASSEMBLY_GLOBAL_INDEX_LEB.
This change also adds support for reading relocations of this
type in WasmObjectFile.cpp.
Since its a globally imported symbol this does mean that
the get_global/set_global instruction won't be valid until
the objects are linked that global used in no longer an
imported global.
Differential Revision: https://reviews.llvm.org/D34172
llvm-svn: 305616
Previously we were writing the value function index space
value but for these types of relocations we want to be
writing the table element index space value.
Add a test case for these relocation types that fails
without this change.
Differential Revision: https://reviews.llvm.org/D33962
llvm-svn: 305253
This creates a new library called BinaryFormat that has all of
the headers from llvm/Support containing structure and layout
definitions for various types of binary formats like dwarf, coff,
elf, etc as well as the code for identifying a file from its
magic.
Differential Revision: https://reviews.llvm.org/D33843
llvm-svn: 304864
The change cleans up and unifies the handling of relocation
entries in WasmObjectWriter. Type index relocation no longer
need to be handled separately.
The only externally visible change should be that type
index relocations are no longer grouped at the end.
Differential Revision: https://reviews.llvm.org/D33918
llvm-svn: 304816
These methods looks like they were originally came from
MCELFObjectTargetWriter but they are never called by the
WasmObjectWriter.
Remove these methods meant the declaration of WasmRelocationEntry
could also move into the cpp file.
Differential Revision: https://reviews.llvm.org/D33905
llvm-svn: 304804
The size of this function was getting a little out of.
control. Split code for writing each section type into
seperate functions.
Differential Revision: https://reviews.llvm.org/D33792
llvm-svn: 304634
Undefined externals don't need to have a size or an offset.
This was broken by r303915. Added a test for this case.
This fixes the "Compile LLVM Torture (o)" step on the wasm
waterfall.
Differential Revision: https://reviews.llvm.org/D33803
llvm-svn: 304505
Also, include global entries for all data symbols, not
just external ones, since these are referenced by the
relocation records.
Add a test case that includes unnamed data.
Differential Revision: https://reviews.llvm.org/D33079
llvm-svn: 303915
Also, add test for data relocations and fix addend to
be signed.
Subscribers: jfb, dschuff
Differential Revision: https://reviews.llvm.org/D32513
llvm-svn: 301690
Add support for the new relocations and linking metadata section support in
https://github.com/WebAssembly/tool-conventions/blob/master/Linking.md. In
particular, this allows LLVM to indicate which variable is the stack pointer,
so that it can be linked with other objects.
This also adds support for emitting type relocations for call_indirect
instructions.
Right now, this is mainly tested by using wabt and hexdump to examine the
output on selected testcases. We'll add more tests as the design stablizes
and more of the pieces are in place.
llvm-svn: 299141
This fix is a follow up a previous change with stored
value types as signed integers in memory.
In future, once the yaml<->wasm binary patche lands we
can add test coverage for this kind of thing.
Differential Revision: https://reviews.llvm.org/D31227
Patch by Sam Clegg
llvm-svn: 298612
A recent change switch the in-memory wasm value types
to be signed integers, but I missing a few cases where
these were being writing to the binary.
Differential Revision: https://reviews.llvm.org/D31014
Patch by Sam Clegg
llvm-svn: 297991
This change updates to the format of the 'names' sectionin the
generated wasm binary to match the latest changesto the design
and 'wabt'.
Differential Revision: https://reviews.llvm.org/D30950
Patch by Sam Clegg
llvm-svn: 297877
Previously we were using the encoded LEB hex values
for the value types. This change uses the decoded
negative value and the LEB encoder to write them out.
Differential Revision: https://reviews.llvm.org/D30847
Patch by Sam Clegg
llvm-svn: 297777
With the "wasm32-unknown-unknown-wasm" triple, this allows writing out
simple wasm object files, and is another step in a larger series toward
migrating from ELF to general wasm object support. Note that this code
and the binary format itself is still experimental.
llvm-svn: 296190
This just adds the basic skeleton for supporting a new object file format.
All of the actual encoding will be implemented in followup patches.
Differential Revision: https://reviews.llvm.org/D26722
llvm-svn: 295803