[PATCH] D114645: [CommandLine] Keep option default value unset if no cl::init() is used

[Don Hinton via Phabricator via llvm-commits]

hintonda added inline comments.


================
Comment at: llvm/unittests/Support/CommandLineTest.cpp:1793
+  StackOption<bool> OptA("a", cl::desc("option a"), cl::init(false));
+  StackOption<bool> OptB(cl::init(false),
       "b", cl::desc("option b -- This option turns on option a"),
----------------
yrouban wrote:
> hintonda wrote:
> > Are these additional `cl::init` calls needed? 
> Yes, I found them needed as the test failed otherwise.
> 
> For example, the first cl::init(false) for the option "a" when reset by cl::ResetAllOptionOccurrences() ...
> 
> CommandLine.h:
> ```
>   template <class T,
>             class = std::enable_if_t<std::is_assignable<T &, T>::value>>
>   void setDefaultImpl() {
>     const OptionValue<DataType> &V = this->getDefault();
>     if (V.hasValue())
>       this->setValue(V.getValue());
>   }
> ```
> 
> Without the explicit default value specified //V.hasValue()// is //None// and //setDefaultValueImple<bool>()// does not call //setValue()//. So the option is left not reset at line 1843.
> 
Ah, got it.  

Would it be possible to tweak `cl::ResetAllOptionOccurrences()` instead?  That way users don't have to modify their code.

I'm just worried about breaking code that's been around for a while.


Repository:
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  https://reviews.llvm.org/D114645/new/

https://reviews.llvm.org/D114645