SuccessChanges

Summary

  1. [clang][cli] Do not marshall only CC1Option flags in BoolOption (details)
  2. [clang][cli] Prevent double denormalization (details)
  3. [mlir] Lookup the latest value with a legal type when remapping values. (details)
Commit 95114f21f5bf1704672dadb45ca7c25efca72e03 by jan_svoboda
[clang][cli] Do not marshall only CC1Option flags in BoolOption

We cannot be sure whether a flag is CC1Option inside the definition of `BoolOption`. Take the example below:

```
let Flags = [CC1Option] in {
  defm xxx : BoolOption<...>;
}
```

where TableGen applies `Flags = [CC1Option]` to the `xxx` and `no_xxx` records **after** they have been is fully declared by `BoolOption`.

For the refactored `-f[no-]debug-pass-manager` flags (see the diff), this means `BoolOption` never adds any marshalling info, as it doesn't see either of the flags as `CC1Option`.

For that reason, we should defensively append the marshalling information to both flags inside `BoolOption`. Now the check for `CC1Option` needs to happen later, in the parsing macro, when all TableGen logic has been resolved.

However, for some flags defined through `BoolOption`, we can run into issues:

```
// Options.td
def fenable_xxx : /* ... */;

// Both flags are CC1Option, the first is implied.
defm xxx : BoolOption<"xxx,
  "Opts.Xxx", DefaultsToFalse,
  ChangedBy<PosFlag, [CC1Option], "", [fenable_xxx]>,
  ResetBy<NegFlag, [CC1Option]>>;
```

When parsing `clang -cc1 -fenable-xxx`:
* we run parsing for `PosFlag`:
  * set `Opts.Xxx` to default `false`,
  * discover `PosFlag` is implied by `-fenable-xxx`: set `Opts.Xxx` to `true`,
  * don't see `-fxxx` on command line: do nothing,
* we run parsing for `NegFlag`:
  * set `Opts.Xxx` to default `false`,
  * discover `NegFlag` cannot be implied: do nothing,
  * don't see `-fno-xxx` on command line: do nothing.

Now we ended up with `Opts.Xxx` set to `false` instead of `true`. For this reason, we need to ensure to append the same `ImpliedByAnyOf` instance to both flags.

This means both parsing runs now behave identically (they set the same default value, run the same "implied by" check, and call `makeBooleanOptionNormalizer` that already has information on both flags, so it returns the same value in both calls).

The solution works well, but what might be confusing is this: you have defined a flag **A** that is not `CC1Option`, but can be implied by another flag **B** that is `CC1Option`:
* if **A** is defined manually, it will never get implied, as the code never runs
```
def no_signed_zeros : Flag<["-"], "fno-signed-zeros">, Group<f_Group>, Flags<[]>,
  MarshallingInfoFlag<"LangOpts->NoSignedZero">, ImpliedByAnyOf<[menable_unsafe_fp_math]>;
```
* if **A** is defined by `BoolOption`, it could get implied, as the code is run by its `CC1Option` counterpart:
```
defm signed_zeros : BoolOption<"signed-zeros",
  "LangOpts->NoSignedZero", DefaultsToFalse,
  ChangedBy<NegFlag, [], "Allow optimizations that ignore the sign of floating point zeros",
            [cl_no_signed_zeros, menable_unsafe_fp_math]>,
  ResetBy<PosFlag, [CC1Option]>, "f">, Group<f_Group>;
```

This is a surprising inconsistency.

One solution might be to somehow propagate the final `Flags` of the implied flag in `ImpliedByAnyOf` and check whether it has `CC1Option` in the parsing macro. However, I think it doesn't make sense to spend time thinking about a corner case that won't come up in real code.

An observation: it is unfortunate that the marshalling information is a part of the flag definition. If we represented it in a separate structure, we could avoid the "double parsing" problem by having a single source of truth. This would require a lot of additional work though.

Note: the original patch missed the `CC1Option` check in the parsing macro, making my reasoning here incomplete. Moreover, it contained a change to denormalization that wasn't necessarily related to these changes, so I've extracted that to a follow-up patch: D93094.

Reviewed By: dexonsmith, Bigcheese

Differential Revision: https://reviews.llvm.org/D93008
The file was modifiedclang/unittests/Frontend/CompilerInvocationTest.cpp
The file was modifiedclang/include/clang/Driver/Options.td
The file was modifiedclang/lib/Frontend/CompilerInvocation.cpp
Commit f2661bed185e14a8f5aa9a54565a8b938a7a10aa by jan_svoboda
[clang][cli] Prevent double denormalization

If both flags created through BoolOption are CC1Option and the keypath has a non-default or non-implied value, the denormalizer gets called twice. If the denormalizer has the ability to generate both flags, we can end up generating the same flag twice.

Reviewed By: dexonsmith, Bigcheese

Differential Revision: https://reviews.llvm.org/D93094
The file was modifiedclang/lib/Frontend/CompilerInvocation.cpp
The file was modifiedclang/include/clang/Driver/Options.td
The file was modifiedclang/unittests/Frontend/CompilerInvocationTest.cpp
The file was modifiedllvm/include/llvm/Option/OptParser.td
Commit f8184d4c44dff1fab13122221f0c23ab50936647 by pifon
[mlir] Lookup the latest value with a legal type when remapping values.

The current condition implies that the target materialization will be
called even if the type is the new operand type is legal, but slightly
different. For example, if there is a bufferization pattern that changes
memref layout, then target materialization for an illegal type
(TensorType) would be called.

Differential Revision: https://reviews.llvm.org/D93126
The file was modifiedmlir/lib/Transforms/Utils/DialectConversion.cpp