[PATCH] D92775: [clang][cli] Add flexible TableGen multiclass for boolean options

[Jan Svoboda via Phabricator via llvm-commits]

jansvoboda11 added a comment.

That's great to hear, thanks.



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Comment at: clang/include/clang/Driver/Options.td:371
+  // TODO: Assert that the flags have different value.
+  // TODO: Assert that only one of the flags can be implied.
+
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Does TableGen support some kind of assertion mechanism?


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Comment at: clang/unittests/Frontend/CompilerInvocationTest.cpp:226
   ASSERT_THAT(GeneratedArgs,
-              Contains(StrEq("-fno-experimental-new-pass-manager")));
+              Not(Contains(StrEq("-fno-experimental-new-pass-manager"))));
   ASSERT_THAT(GeneratedArgs,
----------------
dexonsmith wrote:
> Can you clarify why this was dropped? Was it previously emitted due to a limitation in the implementation, or are we no longer supporting options that always get emitted for clarity?
This option was the only one using the old infrastructure (`BooleanMarshalledFFlag`).
It was set up to always generate the flag, even when it wasn't necessary (this flag sets the keypath to its default value).

I think we should aim to generate only command line arguments that are necessary to preserve the original invocation semantics.
I imagine this will be useful when debugging: one won't need to scan hundreds of flags that don't have any effect on CompilerInvocation.


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Comment at: llvm/include/llvm/Option/OptParser.td:176
   : MarshallingInfoFlag<keypath, defaultvalue> {
-  bit ShouldAlwaysEmit = 1;
-  code Normalizer = "makeBooleanFlagNormalizer(OPT_"#neg_name#")";
----------------
Removal of this property causes the disappearance of `-fno-experimental-new-pass-manager` from list of generated arguments.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D92775/new/

https://reviews.llvm.org/D92775