PCC: remove proof-carrying code (for now?). (#12800)

In late 2023, we built out an experimental feature called
Proof-Carrying Code (PCC), where we attached "facts" to values in the
CLIF IR and built

PCC: remove proof-carrying code (for now?). (#12800)

In late 2023, we built out an experimental feature called
Proof-Carrying Code (PCC), where we attached "facts" to values in the
CLIF IR and built verification of these facts after lowering to
machine instructions. We also added "memory types" describing layout
of memory and a "checked" flag on memory operations such that we could
verify that any checked memory operation accessed valid memory (as
defined by memory types attached to pointer values via
facts). Wasmtime's Cranelift backend then put appropriate memory types
and facts in its IR such that all accesses to memory (aspirationally)
could be checked, taking the whole mid-end and lowering backend of
Cranelift out of the trusted core that enforces SFI.

This basically worked, at the time, for static memories; but never for
dynamic memories, and then work on the feature lost
prioritization (aka I had to work on other things) and I wasn't able
to complete it and put it in fuzzing/enable it as a production option.

Unfortunately since then it has bit-rotted significantly -- as we add
new backend optimizations and instruction lowerings we haven't kept
the PCC framework up to date.

Inspired by the discussion in #12497 I think it's time to delete
it (hopefully just "for now"?) unless/until we can build it again. And
when we do that, we should probably get it to the point of validating
robust operation on all combinations of memory configurations before
merging. (That implies a big experiment branch rather than a bunch of
eager PRs in-tree, but so it goes.) I still believe it is possible to
build this (and I have ideas on how to do it!) but not right now.

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Cranelift: add debug tag infrastructure. (#11768)

* Cranelift: add debug tag infrastructure.

This PR adds *debug tags*, a kind of metadata that can attach to CLIF
instructions and be lowered to VCo

Cranelift: add debug tag infrastructure. (#11768)

* Cranelift: add debug tag infrastructure.

This PR adds *debug tags*, a kind of metadata that can attach to CLIF
instructions and be lowered to VCode instructions and as metadata on
the produced compiled code. It also adds opaque descriptor blobs
carried with stackslots. Together, these two features allow decorating
IR with first-class debug instrumentation that is properly preserved
by the compiler, including across optimizations and
inlining. (Wasmtime's use of these features will come in followup
PRs.)

The key idea of a "debug tag" is to allow the Cranelift embedder to
express whatever information it needs to, in a format that is opaque
to Cranelift itself, except for the parts that need translation during
lowering. In particular, the `DebugTag::StackSlot` variant gets
translated to a physical offset into the stackframe in the compiled
metadata output. So, for example, the embedder can emit a tag
referring to a stackslot, and another describing an offset in that
stackslot.

The debug tags exist as a *sequence* on any given instruction; the
meaning of the sequence is known only to the embedder, *except* that
during inlining, the tags for the inlining call instruction are
prepended to the tags of inlined instructions. In this way, a
canonical use-case of tags as describing original source-language
frames can preserve the source-language view even when multiple
functions are inlined into one.

The descriptor on a stackslot may look a little odd at first, but its
purpose is to allow serializing some description of
stackslot-contained runtime user-program data, in a way that is firmly
attached to the stackslot. In particular, in the face of inlining,
this descriptor is copied into the inlining (parent) function from the
inlined function when the stackslot entity is copied; no other
metadata outside Cranelift needs to track the identity of stackslots
and know about that motion. This fits nicely with the ability of tags
to refer to stackslots; together, the embedder can annotate
instructions as having certain state in stackslots, and describe the
format of that state per stackslot.

This infrastructure is tested with some compile-tests now;
testing of the interpretation of the metadata output will come with
end-to-end debug instrumentation tests in a followup PR.

* Review feedback: add back sequence points and enforce tags only on sequence points or calls.

* Use Vecs for debug metadata in MachBuffer to avoid SmallVec size penalty in not-used case.

* Review feedback: switch from inlined stackslot descriptor blobs to u64 keys.

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fix: accurate leaf detection (#11581)

* feat: add is_call() method to MachInst trait and VCode analysis

Add is_call() method to MachInst trait to enable accurate leaf function
detection during regi

fix: accurate leaf detection (#11581)

* feat: add is_call() method to MachInst trait and VCode analysis

Add is_call() method to MachInst trait to enable accurate leaf function
detection during register allocation. Update VCode compute_clobbers() to
return (clobbers, is_leaf) tuple by analyzing actual call instructions
in machine code.

* feat: implement is_call() method across all architectures

Implement is_call() method for all architecture-specific MachInst
implementations:

- x64: Detects CallKnown, CallUnknown, ReturnCall variants, and TLS
calls (ElfTlsGetAddr, MachOTlsGetAddr)
- aarch64: Detects Call, CallInd, ReturnCall variants, and TLS calls
(ElfTlsGetAddr, MachOTlsGetAddr)
- riscv64: Detects Call, CallInd, ReturnCall variants, and ElfTlsGetAddr
- s390x: Detects CallKnown, CallUnknown, ReturnCall variants
- pulley: Detects Call, CallIndirect, ReturnCall variants

Co-authored-by: bjorn3 <[email protected]>

* feat: improve leaf function detection and pass is_leaf to FrameLayout

* test: add filetests for leaf detection

* test: update expected outputs for accurate leaf function detection

* test(riscv64): update filetests output

---------

Co-authored-by: bjorn3 <[email protected]>

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Update Wasmtime to the 2024 Rust Edition (#10806)

* Update Wasmtime to the 2024 Rust Edition

Now that our MSRV supports the 2024 edition it's possible to make this
switch. This commit moves Wasmtim

Update Wasmtime to the 2024 Rust Edition (#10806)

* Update Wasmtime to the 2024 Rust Edition

Now that our MSRV supports the 2024 edition it's possible to make this
switch. This commit moves Wasmtime to the 2024 Edition to keep
up-to-date with Rust idioms and access many of the edition features
exclusive to the 2024 edition.

prtest:full

* Reformat with the 2024 edition

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[DI] Dump value label assignments in a table (#10549)

* Dump compilation start/end

* [DI] Log value label ranges in a table

Sample table:

|Inst |IP |VL0 |VL1 |VL3 |VL4 |VL5

[DI] Dump value label assignments in a table (#10549)

* Dump compilation start/end

* [DI] Log value label ranges in a table

Sample table:

|Inst |IP |VL0 |VL1 |VL3 |VL4 |VL5 |VL7 |VL10 |VL11 |VL4294967294|
|--------|----|--------|---------|---------|--------|--------|--------|---------|--------|------------|
|Inst 0 |53 | | | | | | | | | | | | | | | | | | |
|Inst 1 |53 | | | | | | | | | | | | | | | | | | |
|Inst 2 |60 |v194|p2i|v232|p12i| | | | | | | | | | | | |v192|p7i |
|Inst 3 |64 |* |p2i|* |p12i|v231|p13i| | | | | | | | | | |* |p7i |
|Inst 4 |68 |* |p2i|* |p12i|* |p13i| | | | | | | | | | |* |p7i |
|Inst 5 |72 |* |p2i|* |p12i|* |p13i| | | | | | | | | | |* |p7i |
|Inst 6 |76 |* |p2i|* |p12i|* |p13i| | | | | | | | | | |* |p7i |
|Inst 7 |87 |* | |* |p12i|* |p13i| | | | | | | | | | |* |p7i |
|Inst 8 |92 |* | |* |p12i|* |p13i|v227|p0i| | | | | | | | |* |p15i |
|Inst 9 |94 |* | |v204| |v204| |v204| |v204| |v204| |v204| |v204| |* |p15i |
|Inst 10 |100 |* | |* | |* | |* | |* | |* | |* | |* | |* |p15i |
|Inst 11 |105 |* | |* | |* | |* | |v226|p9i|* | |* | |* | |* |p15i |
|Inst 12 |109 |* | |* | |* | |* | |* | |v225|p9i|* | |* | |* |p15i |
|Inst 13 |114 |* | |* | |* | |* | |* | |* | |* | |* | |* |p15i |
|Inst 14 |119 |* | |* | |* | |* | |* | |* | |* | |* | |* |p15i |
|Inst 15 |125 |* | |* | |* | |* | |* | |* | |* | |* | |* |p15i |
|Inst 16 |129 |* | |* | |* | |* | |* | |* | |v223|p11i|* | |* |p15i |
|Inst 17 |134 |* | |* | |* | |* | |* | |* | |* | |* | |* |p15i |
|Inst 18 |134 |* | |* | |* | |* | |* | |* | |* | |* | |* |p15i |
|Inst 19 |139 |* | |* | |* | |* | |* | |* | |* | |v222|p0i|* |p15i |
|Inst 20 |143 |* | |* | |* | |* | |* | |* | |* | |* |p0i|* |p15i |
|Inst 21 |143 |* | |* | |* | |* | |* | |* | |* | |* |p0i|* | |

This will make it much easier to diagnose problems with incomplete/missing live ranges.

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Cranelift: initial try_call / try_call_indirect (exception) support. (#10510)

* Cranelift: initial try_call / try_call_indirect (exception) support.

This PR adds `try_call` and `try_call_indirect`

Cranelift: initial try_call / try_call_indirect (exception) support. (#10510)

* Cranelift: initial try_call / try_call_indirect (exception) support.

This PR adds `try_call` and `try_call_indirect` instructions, and
lowerings on four of five ISAs (x86-64, aarch64, riscv64, pulley; s390x
has its own non-shared ABI code that will need separate work).

It extends CLIF to support these instructions as new kinds of branches,
and extends block-calls to accept `retN` and `exnN` block-call args that
carry the normal return values or exception payloads (respectively) into
the appropriate successor blocks.

It wires up the "normal return path" so that it continues to work.
It updates the ABI so that unwinding is possible without an initial
register state at throw: specifically, as per our RFC, all registers are
clobbered. It also includes metadata in the `MachBuffer` that describes
exception-catch destinations. However, no unwinder exists to interpret
these catch-destinations yet, so they are untested.

* Add try_call_indirect lowering as well.

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Don't allow jump instructions after a terminator in is_block_basic (#9592)

We merged brz/brnz+jump into br_if a while ago.

Enforce `uninlined_format_args` for the workspace (#9065)

* Enforce `uninlined_format_args` for the workspace

* fix: failing `Monolith Checks` job

* fix: formatting

Cranelift: Add a helper for getting a block's successors (#9067)

Co-authored-by: Trevor Elliott <[email protected]>

cranelift: Remove support for WebAssembly tables (#8124)

Wasmtime no longer needs any of this infrastructure and neither should
anybody else.

This diff is nearly identical to @bjorn3's version of t

cranelift: Remove support for WebAssembly tables (#8124)

Wasmtime no longer needs any of this infrastructure and neither should
anybody else.

This diff is nearly identical to @bjorn3's version of the same change,
except I didn't remove Uimm64, which has started being used in other
places. I forgot bjorn3 had already tackled this part until after I was
already done, but it's reassuring that we both made the same changes.

https://github.com/bjorn3/wasmtime/commit/fb82ccb3948e949641a6d9581aa84472f68f97b8

Fixes #5532

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PCC: initial end-to-end integration with Wasmtime's static memories. (#7274)

* PCC: add facts to global values, parse and print them. No verification yet.

Co-authored-by: Nick Fitzgerald <fitzgen@g

PCC: initial end-to-end integration with Wasmtime's static memories. (#7274)

* PCC: add facts to global values, parse and print them. No verification yet.

Co-authored-by: Nick Fitzgerald <[email protected]>

* PCC: propagate facts on GV loads and check them.

Co-authored-by: Nick Fitzgerald <[email protected]>

* PCC: support propagating facts on iteratively-elaborated GVs as well.

Co-authored-by: Nick Fitzgerald <[email protected]>

* PCC: fix up Wasmtime uses of GVs after refactors to memflags handling.

Co-authored-by: Nick Fitzgerald <[email protected]>

* PCC: working end-to-end for static memories!

Co-authored-by: Nick Fitzgerald <[email protected]>

* PCC: add toplevel Wasmtime option `-C enable-pcc=y`.

* Fix filetests build.

* Review feedback, and blessed test updates due to GV legalization changes.

---------

Co-authored-by: Nick Fitzgerald <[email protected]>

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PCC: add basic "memory types". (#7219)

* PCC: define memory types and add some examples in filetests (no parsing yet).

* PCC: add a notion of memory types.

Co-authored-by: Nick Fitzgerald <fitzgen

PCC: add basic "memory types". (#7219)

* PCC: define memory types and add some examples in filetests (no parsing yet).

* PCC: add a notion of memory types.

Co-authored-by: Nick Fitzgerald <[email protected]>

* Transition `points_to` to a `memory` (static memory) memory-type.

* Review feedback.

---------

Co-authored-by: Nick Fitzgerald <[email protected]>

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cranelift: Consider functions with TLS values as non leaf (#7177)

Decouple `serde` from its `derive` crate (#6917)

By not activating the `derive` feature on `serde`, the compilation speed
can be improved by a lot. This is because `serde` can then compile in
parall

Decouple `serde` from its `derive` crate (#6917)

By not activating the `derive` feature on `serde`, the compilation speed
can be improved by a lot. This is because `serde` can then compile in
parallel to `serde_derive`, allowing it to finish compilation possibly
even before `serde_derive`, unblocking all the crates waiting for
`serde` to start compiling much sooner.

As it turns out the main deciding factor for how long the compile time of a
project is, is primarly determined by the depth of dependencies rather
than the width. In other words, a crate's compile times aren't affected
by how many crates it depends on, but rather by the longest chain of
dependencies that it needs to wait on. In many cases `serde` is part of
that long chain, as it is part of a long chain if the `derive` feature
is active:

`proc-macro2` compile build script > `proc-macro2` run build script >
`proc-macro2` > `quote` > `syn` > `serde_derive` > `serde` >
`serde_json` (or any crate that depends on serde)

By decoupling it from `serde_derive`, the chain is shortened and compile
times get much better.

Check this issue for a deeper elaboration:
https://github.com/serde-rs/serde/issues/2584

For `wasmtime` I'm seeing a reduction from 24.75s to 22.45s when
compiling in `release` mode. This is because wasmtime through `gimli`
has a dependency on `indexmap` which can only start compiling when
`serde` is finished, which you want to happen as early as possible so
some of wasmtime's dependencies can start compiling.

To measure the full effect, the dependencies can't by themselves
activate the `derive` feature. I've upstreamed a patch for
`fxprof-processed-profile` which was the only dependency that activated
it for `wasmtime` (not yet published to crates.io). `wasmtime-cli` and
co. may need patches for their dependencies to see a similar
improvement.

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A bunch of minor cleanups (#6767)

* Remove DisplayFunctionAnnotations

It used to exist for printing the debuginfo value ranges with the clif
ir, but this no longer happens, so it is now useless.

*

A bunch of minor cleanups (#6767)

* Remove DisplayFunctionAnnotations

It used to exist for printing the debuginfo value ranges with the clif
ir, but this no longer happens, so it is now useless.

* Remove debug info collection from DummyEnvironment

There are no remaining users of it

* Remove ComparableSourceLoc

It is unused

* Move LabelValueLoc re-export out of the ir module

It encodes target specific information, so shouldn't be in the target
independent ir module.

* Remove RelocDistance dependency from ir::extfunc and ir::globalvalue

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Allow serializing all cranelift-module data structures (#6172)

* Remove ModuleCompiledFunction

The same information can be retrieved using

ctx.compiled_code().unwrap().code_info().total_size

In a

Allow serializing all cranelift-module data structures (#6172)

* Remove ModuleCompiledFunction

The same information can be retrieved using

ctx.compiled_code().unwrap().code_info().total_size

In addition for Module implementations that don't immediately compile the
given function there is no correct value that can be returned.

* Don't give anonymous functions and data objects an internal name

This internal name can conflict if a module is serialized and then
deserialized into another module. It also wasn't used by any of the
Module implementations anyway.

* Allow serializing all cranelift-module data structures

This allows a Module implementation to serialize it's internal state and
deserialize it in another compilation session. For example to implement
LTO or to load the module into cranelift-interpreter.

* Use expect

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Minir typo/Grammar fixes (#6187)

* fix typo

* add test to check that Option<EntityRef> is twice as large as EntityRef

* grammar

* grammar

* reverse snakecase -- Not sure if folks want this type

Minir typo/Grammar fixes (#6187)

* fix typo

* add test to check that Option<EntityRef> is twice as large as EntityRef

* grammar

* grammar

* reverse snakecase -- Not sure if folks want this type of change

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cranelift: Implement PartialEq in `Function` (#6157)

Rework br_table to use BlockCall (#5731)

Rework br_table to use BlockCall, allowing us to avoid adding new nodes during ssa construction to hold block arguments. Additionally, many places where we p

Rework br_table to use BlockCall (#5731)

Rework br_table to use BlockCall, allowing us to avoid adding new nodes during ssa construction to hold block arguments. Additionally, many places where we previously matched on InstructionData to extract branch destinations can be replaced with a use of branch_destination or branch_destination_mut.

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Move default blocks into jump tables (#5756)

Move the default block off of the br_table instrution, and into the JumpTable that it references.

Move jump tables to the DataFlowGraph (#5745)

Move the storage for jump tables off of FunctionStencil and onto DataFlowGraph. This change is in service of #5731, making it easier to access the jump

Move jump tables to the DataFlowGraph (#5745)

Move the storage for jump tables off of FunctionStencil and onto DataFlowGraph. This change is in service of #5731, making it easier to access the jump table data in the context of helpers like inst_values.

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Add assertions for matches that used to use analyze_branch (#5733)

Following up from #5730, add debug assertions to ensure that new branch instructions don't slip through matches that used to use an

Add assertions for matches that used to use analyze_branch (#5733)

Following up from #5730, add debug assertions to ensure that new branch instructions don't slip through matches that used to use analyze_branch.

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Refactor matches that used to consume BranchInfo (#5734)

Explicitly borrow the instruction data, and use a mutable borrow to avoid rematch.

Remove analyze_branch and BranchInfo (#5730)

We don't have overlap in behavior for branch instructions anymore, so we can remove analyze_branch and instead match on the InstructionData directly.

Remove analyze_branch and BranchInfo (#5730)

We don't have overlap in behavior for branch instructions anymore, so we can remove analyze_branch and instead match on the InstructionData directly.

Co-authored-by: Jamey Sharp <[email protected]>

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cranelift: Add a conditional branch instruction with two targets (#5446)

Add a conditional branch instruction with two targets: brif. This instruction will eventually replace brz and brnz, as it enc

cranelift: Add a conditional branch instruction with two targets (#5446)

Add a conditional branch instruction with two targets: brif. This instruction will eventually replace brz and brnz, as it encompasses the behavior of both.

This PR also changes the InstructionData layout for instruction formats that hold BlockCall values, taking the same approach we use for Value arguments. This allows branch_destination to return a slice to the BlockCall values held in the instruction, rather than requiring that we pattern match on InstructionData to fetch the then/else blocks.

Function generation for fuzzing has been updated to generate uses of brif, and I've run the cranelift-fuzzgen target locally for hours without triggering any new failures.

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