Don't use Optional::hasValue (NFC)

[lld] Use value_or instead of getValueOr (NFC)

Fix warnings about variables that are set but only used in debug mode

Add void casts to mark the variables used, next to the places where
they are used in assert or `LLVM_DEBUG()` expressions.

Diff

Fix warnings about variables that are set but only used in debug mode

Add void casts to mark the variables used, next to the places where
they are used in assert or `LLVM_DEBUG()` expressions.

Differential Revision: https://reviews.llvm.org/D123117

show more ...

[WebAssembly] Second phase of implemented extended const proposal

This change continues to lay the ground work for supporting extended
const expressions in the linker.

The included test covers obje

[WebAssembly] Second phase of implemented extended const proposal

This change continues to lay the ground work for supporting extended
const expressions in the linker.

The included test covers object file reading and writing and the YAML
representation.

Differential Revision: https://reviews.llvm.org/D121349

show more ...

[lld][WebAssembly] Improve error reporting for bad ar archive members

Show the name of of the archive in the error message as well as the name
of the object within it.

Differential Revision: https:

[lld][WebAssembly] Improve error reporting for bad ar archive members

Show the name of of the archive in the error message as well as the name
of the object within it.

Differential Revision: https://reviews.llvm.org/D120689

show more ...

[MC][WebAssembly] Fix crash when relocation addend underlows U32

For the object file writer we need to allow the underflow (ar write
zero), but for the final linker output we should probably generat

[MC][WebAssembly] Fix crash when relocation addend underlows U32

For the object file writer we need to allow the underflow (ar write
zero), but for the final linker output we should probably generate an
error (I've left that as a TODO for now).

Fixes: https://github.com/llvm/llvm-project/issues/54012

Differential Revision: https://reviews.llvm.org/D120522

show more ...

[lld][WebAssembly] Handle TLS symbols in older object file

In older versions of llvm (e.g. llvm 13), symbols were not individually
flagged as TLS. In this case, the indent was to implicitly mark an

[lld][WebAssembly] Handle TLS symbols in older object file

In older versions of llvm (e.g. llvm 13), symbols were not individually
flagged as TLS. In this case, the indent was to implicitly mark any
symbols defined in TLS segments as TLS. However, we were not performing
this implicit conversion if the segment was explicitly marked as TLS

As it happens, llvm 13 was branched between the addition of the segment
flag and the addition of the symbol flag. See:

- segment flag added: https://reviews.llvm.org/D102202
- symbol flag added: https://reviews.llvm.org/D109426

Testing this is tricky because the assembler will imply the TLS status
of the symbol based on the segment its declared in, so we are forced to
use a yaml file here.

Fixes: https://github.com/emscripten-core/emscripten/issues/15891

Differential Revision: https://reviews.llvm.org/D118414

show more ...

Re-land [LLD] Remove global state in lldCommon

Move all variables at file-scope or function-static-scope into a hosting structure (lld::CommonLinkerContext) that lives at lldMain()-scope. Drivers wi

Re-land [LLD] Remove global state in lldCommon

Move all variables at file-scope or function-static-scope into a hosting structure (lld::CommonLinkerContext) that lives at lldMain()-scope. Drivers will inherit from this structure and add their own global state, in the same way as for the existing COFFLinkerContext.

See discussion in https://lists.llvm.org/pipermail/llvm-dev/2021-June/151184.html

The previous land f860fe362282ed69b9d4503a20e5d20b9a041189 caused issues in https://lab.llvm.org/buildbot/#/builders/123/builds/8383, fixed by 22ee510dac9440a74b2e5b3fe3ff13ccdbf55af3.

Differential Revision: https://reviews.llvm.org/D108850

show more ...

Revert [LLD] Remove global state in lldCommon

It seems to be causing issues on https://lab.llvm.org/buildbot/#/builders/123/builds/8383

[LLD] Remove global state in lldCommon

Move all variables at file-scope or function-static-scope into a hosting structure (lld::CommonLinkerContext) that lives at lldMain()-scope. Drivers will inher

[LLD] Remove global state in lldCommon

Move all variables at file-scope or function-static-scope into a hosting structure (lld::CommonLinkerContext) that lives at lldMain()-scope. Drivers will inherit from this structure and add their own global state, in the same way as for the existing COFFLinkerContext.

See discussion in https://lists.llvm.org/pipermail/llvm-dev/2021-June/151184.html

Differential Revision: https://reviews.llvm.org/D108850

show more ...

[lld][WebAssembly] Fix for debug relocations against undefined function symbols

This is very similar to https://reviews.llvm.org/D103557 but applies to
symbols which are undefined at link time rathe

[lld][WebAssembly] Fix for debug relocations against undefined function symbols

This is very similar to https://reviews.llvm.org/D103557 but applies to
symbols which are undefined at link time rather than compile time.

We already have code that handles symbols which were defined at link
time but dead stripped by `--gc-sections` (See
`test/wasm/debug-removed-fn.ll`). In that case the symbols are not live
(!isLive()). However, we can also have live symbols (which are
references by the program) but which are undefined at link time and are
imported by the linker.

In the test case here the symbol `undef` is used but is not defined
in the program but is imported by the linker due to the
`--import-undefined` flag.

Fixes: https://github.com/emscripten-core/emscripten/issues/15528

Differential Revision: https://reviews.llvm.org/D114921

show more ...

[lld][WebAssembly] Handle TLS variables in Symbol::getVA. NFC

In the shared memory case we can always assume that TLS addresses
are relative to __tls_base. In the non-shared memory case TLS
variabl

[lld][WebAssembly] Handle TLS variables in Symbol::getVA. NFC

In the shared memory case we can always assume that TLS addresses
are relative to __tls_base. In the non-shared memory case TLS
variables are absolute, just like normal data addresses.

This simplifies the code in calcNewValue so that TLS relocations
no longer need special handling.

Differential Revision: https://reviews.llvm.org/D112831

show more ...

[lld][WebAssembly] Handle duplicate archive member names in ThinLTO

This entire change, including the test case, comes almost verbatim
from the ELF driver.

Fixes: https://github.com/emscripten-core

[lld][WebAssembly] Handle duplicate archive member names in ThinLTO

This entire change, including the test case, comes almost verbatim
from the ELF driver.

Fixes: https://github.com/emscripten-core/emscripten/issues/12763

Differential Revision: https://reviews.llvm.org/D112723

show more ...

fix comment typos to cycle bots

[WebAssembly] Make EH work with dynamic linking

This makes Wasm EH work with dynamic linking. So far we were only able
to handle destructors, which do not use any tags or LSDA info.

1. This uses `T

[WebAssembly] Make EH work with dynamic linking

This makes Wasm EH work with dynamic linking. So far we were only able
to handle destructors, which do not use any tags or LSDA info.

1. This uses `TargetExternalSymbol` for `GCC_except_tableN` symbols,
which points to the address of per-function LSDA info. It is more
convenient to use than `MCSymbol` because it can take additional
target flags.

2. When lowering `wasm_lsda` intrinsic, if PIC is enabled, make the
symbol relative to `__memory_base` and generate the `add` node. If
PIC is disabled, continue to use the absolute address.

3. Make tag symbols (`__cpp_exception` and `__c_longjmp`) undefined in
the backend, because it is hard to make it work with dynamic
linking's loading order. Instead, we make all tag symbols undefined
in the LLVM backend and import it from JS.

4. Add support for undefined tags to the linker.

Companion patches:
- https://github.com/WebAssembly/binaryen/pull/4223
- https://github.com/emscripten-core/emscripten/pull/15266

Reviewed By: sbc100

Differential Revision: https://reviews.llvm.org/D111388

show more ...

[WebAssembly] Remove WasmTagType

This removes `WasmTagType`. `WasmTagType` contained an attribute and a
signature index:
```
struct WasmTagType {
uint8_t Attribute;
uint32_t SigIndex;
};
```

Cu

[WebAssembly] Remove WasmTagType

This removes `WasmTagType`. `WasmTagType` contained an attribute and a
signature index:
```
struct WasmTagType {
uint8_t Attribute;
uint32_t SigIndex;
};
```

Currently the attribute field is not used and reserved for future use,
and always 0. And that this class contains `SigIndex` as its property is
a little weird in the place, because the tag type's signature index is
not an inherent property of a tag but rather a reference to another
section that changes after linking. This makes tag handling in the
linker also weird that tag-related methods are taking both `WasmTagType`
and `WasmSignature` even though `WasmTagType` contains a signature
index. This is because the signature index changes in linking so it
doesn't have any info at this point. This instead moves `SigIndex` to
`struct WasmTag` itself, as we did for `struct WasmFunction` in D111104.

In this CL, in lib/MC and lib/Object, this now treats tag types in the
same way as function types. Also in YAML, this removes `struct Tag`,
because now it only contains the tag index. Also tags set `SigIndex` in
`WasmImport` union, as functions do.

I think this makes things simpler and makes tag handling more in line
with function handling. These two shares similar properties in that both
of them have signatures, but they are kind of nominal so having the same
signature doesn't mean they are the same element.

Also a drive-by fix: the reserved 'attirubute' part's encoding changed
from uleb32 to uint8 a while ago. This was fixed in lib/MC and
lib/Object but not in YAML. This doesn't change object files because the
field's value is always 0 and its encoding is the same for the both
encoding.

This is effectively NFC; I didn't mark it as such just because it
changed YAML test results.

Reviewed By: sbc100, tlively

Differential Revision: https://reviews.llvm.org/D111086

show more ...

[Object][WebAssemlby] Report function types (signatures). NFC

This simplifies the code in a number of ways and avoids
having to track functions and their types separately.

Differential Revision: ht

[Object][WebAssemlby] Report function types (signatures). NFC

This simplifies the code in a number of ways and avoids
having to track functions and their types separately.

Differential Revision: https://reviews.llvm.org/D111104

show more ...

[lld][WebAssembly] Cleanup output of --verbose

Remove some unnecessary logging from wasm-ld when running under
`--verbose`. Unlike `-debug` this logging is available in release
builds. This change

[lld][WebAssembly] Cleanup output of --verbose

Remove some unnecessary logging from wasm-ld when running under
`--verbose`. Unlike `-debug` this logging is available in release
builds. This change makes it little more minimal/readable.

Also, avoid compiling the `debugWrite` function in releaase builds
where it does nothing. This should remove a lot debug strings from
the binary, and avoid having to construct unused debug strings at
runtime.

Differential Revision: https://reviews.llvm.org/D109583

show more ...

[WebAssembly] Add explict TLS symbol flag

As before we maintain backwards compat with older object files
by also infering the TLS flag based on the name of the segment.

This change is was split out

[WebAssembly] Add explict TLS symbol flag

As before we maintain backwards compat with older object files
by also infering the TLS flag based on the name of the segment.

This change is was split out from https://reviews.llvm.org/D108877.

Differential Revision: https://reviews.llvm.org/D109426

show more ...

[LTO] Add SelectionKind to IRSymtab and use it in ld.lld/LLVMgold

In PGO, a C++ external linkage function `foo` has a private counter
`__profc_foo` and a private `__profd_foo` in a `comdat nodedupli

[LTO] Add SelectionKind to IRSymtab and use it in ld.lld/LLVMgold

In PGO, a C++ external linkage function `foo` has a private counter
`__profc_foo` and a private `__profd_foo` in a `comdat nodeduplicate`.

A `__attribute__((weak))` function `foo` has a weak hidden counter `__profc_foo`
and a private `__profd_foo` in a `comdat nodeduplicate`.

In `ld.lld a.o b.o`, say a.o defines an external linkage `foo` and b.o
defines a weak `foo`. Currently we treat `comdat nodeduplicate` as `comdat any`,
ld.lld will incorrectly consider `b.o:__profc_foo` non-prevailing. In the worst
case when `b.o:__profd_foo` is retained and `b.o:__profc_foo` isn't, there will
be dangling reference causing an `undefined hidden symbol` error.

Add SelectionKind to `Comdat` in IRSymtab and let linkers ignore nodeduplicate comdat.

Differential Revision: https://reviews.llvm.org/D106228

show more ...

[WebAssembly] Support R_WASM_MEMORY_ADDR_TLS_SLEB64 for wasm64

Also fixed TLS tests swapping addr & value in store op
Differential Revision: https://reviews.llvm.org/D106096

[WebAssembly] Rename event to tag

We recently decided to change 'event' to 'tag', and 'event section' to
'tag section', out of the rationale that the section contains a
generalized tag that referenc

[WebAssembly] Rename event to tag

We recently decided to change 'event' to 'tag', and 'event section' to
'tag section', out of the rationale that the section contains a
generalized tag that references a type, which may be used for something
other than exceptions, and the name 'event' can be confusing in the web
context.

See
- https://github.com/WebAssembly/exception-handling/issues/159#issuecomment-857910130
- https://github.com/WebAssembly/exception-handling/pull/161

Reviewed By: tlively

Differential Revision: https://reviews.llvm.org/D104423

show more ...

[lld][WebAssemlby] Fix for string merging of -dwarf-5 sections

We were mistakenly treating `.debug_str_offsets` as a string mergable
section when it is not (it contains integers not strings). This

[lld][WebAssemlby] Fix for string merging of -dwarf-5 sections

We were mistakenly treating `.debug_str_offsets` as a string mergable
section when it is not (it contains integers not strings). This is an
indication that we really should find a way to store flags for custom
sections.

Fixes: https://bugs.llvm.org/show_bug.cgi?id=48828
Fixes: https://bugs.chromium.org/p/chromium/issues/detail?id=1172217

Differential Revision: https://reviews.llvm.org/D103486

show more ...

[WebAssembly] Fix PIC/GOT codegen for wasm64

__table_base is know 64-bit, since in LLVM it represents a function pointer offset
__table_base32 is a copy in wasm32 for use in elem init expr, since no

[WebAssembly] Fix PIC/GOT codegen for wasm64

__table_base is know 64-bit, since in LLVM it represents a function pointer offset
__table_base32 is a copy in wasm32 for use in elem init expr, since no truncation may be used there.
New reloc R_WASM_TABLE_INDEX_REL_SLEB64 added

Differential Revision: https://reviews.llvm.org/D101784

show more ...

[lld][WebAssembly] Enable string tail merging in debug sections

This is a followup to https://reviews.llvm.org/D97657 which
applied string tail merging to data segments.

Fixes: https://bugs.llvm.or

[lld][WebAssembly] Enable string tail merging in debug sections

This is a followup to https://reviews.llvm.org/D97657 which
applied string tail merging to data segments.

Fixes: https://bugs.llvm.org/show_bug.cgi?id=48828

Differential Revision: https://reviews.llvm.org/D102436

show more ...