[luci] Introduce the parent class method to luci::Pass

[tomdol]

This directive fixes a build break caused by a compiler error emitted when compiling with -Werror=overloaded-virtual flag switched on. The error is about the logo::Pass::run method being hidden by luci::Pass::run.

ONE-DCO-1.0-Signed-off-by: Tomasz Dolbniak [email protected]

Related issue NPU_Compiler/issues/19901

[seanshpark]

@lemmaa , what is the guide for putting internal server URLs?

[seanshpark]

I don't understand why add this here.
I cannot accept the resolution method. please find another way of solution.

[tomdol]

This is in fact the solution. The reason this error occurs in the first place is that the luci::Pass::run(luci::Module *) has a different signature than the parent's loco::Pass::run(loco::Graph *) and this can cause overload resolution problems when compiling the code in certain situations. This is why newer compilers report a warning and the -Werror=overloaded-virtual makes it an error which basically blocks the build on Ubuntu 24.

The using directive adds the logo::Pass::run method to the overload set of the luci::Pass class which makes the warning(error) go away and most importantly - it doesn't break anything.

[seanshpark]

IMHO you got it wrong. luci::Pass::run(luci::Module *) is also pure virtual so that inherit class SHOULD also override.
You can inherit from loco::Pass if do not want to use luci::Module * parameter.

[tomdol]

The original build error (screenshot in the linked issue) comes from a file CircleNodePass.h which includes the logo/Pass.h header and contains a class which inherits from logo::Pass. This is correct and matches what you said above - CircleNodePass overrides run(loco::Graph* graph) and doesn't touch the version which operates on luci::Module.

Yet the compiler produces an error about luci::Pass::run hiding logo::Pass::run withing this compilation context.

Here's a smaller snippet that demonstrates how hiding the virtual methods interferes with name lookup and overload resolution https://ideone.com/lI3QNL

Uncomment the using A::run; line fixes the problem and this is exactly what I'm proposing here.

[tomdol]

The only other solution I can imagine is renaming the conflicting methods so that they don't hide each other:

logo::Pass::run(Graph*) -> logo::Pass::run_on_graph(Graph*)
luci::Pass::run(Module*) -> luci::Pass::run_on_module(Module*)

[seanshpark]

Have you tried overriding luci::Pass::run(luci::Module *) ? something like

   bool run(luci::Module *) override { throw "NYI"; }

[batcheu]

First of all, I'm not familiar with this kind of warning and I didn't understand neither what above code tries to solve at the first.
So, I've searched the general solution for this warning and found that most of directions guided as @tomdol's.

"In cases where the different signatures are not an accident, the simplest solution is to add a using-declaration to the derived class to un-hide the base function, e.g. add using A::f; to B. "

• from GCC Docs : -Woverloaded-virtual

We may solve the issue in different ways (e.g. duplicating logo::pass to luci:pass, renaming the functions ...) but current suggestion seems quite optimal for me ;)

[seanshpark]

I assume this issue is to fix for U24.04 cause of your situation.
Current ONE/compiler does not have CI for U24.04.
I cannot confirm this check is appropriate for the issue in internal compiler.
Personally I do not want this patch to land.

What I can suggest is written in #14589 (comment)

[dahlinPL]

Please take a look into #14448, I believe this workaround can be removed after fixing it in a way presented in this PR, @hseok-oh, you're author of #14448 what's your opinion?

[hseok-oh]

@dahlinPL @seanshpark We can see this warning when we are using Clang or latest GCC version.

https://stackoverflow.com/questions/18515183/c-overloaded-virtual-function-warning-by-clang

This warning is there to prevent accidental hiding of overloads when overriding is intended.

Clang users have been experiencing this issue for more than 10 years. And now GCC has begun to warn this issue, unfortunately.
I added comment that TODO Remove -Wno-reoder and -Wno-overloaded-virtual on #14448. But I've changed my opinion because I think overloaded-virtual warning is excessive. I want to ignore this warning by keeping flag -Wno-overloaded-virtual.

[dahlinPL]

@dahlinPL @seanshpark We can see this warning when we are using Clang or latest GCC version.

https://stackoverflow.com/questions/18515183/c-overloaded-virtual-function-warning-by-clang

This warning is there to prevent accidental hiding of overloads when overriding is intended.

Clang users have been experiencing this issue for more than 10 years. And now GCC has begun to warn this issue, unfortunately. I added comment that TODO Remove -Wno-reoder and -Wno-overloaded-virtual on #14448. But I've changed my opinion because I think overloaded-virtual warning is excessive. I want to ignore this warning by keeping flag -Wno-overloaded-virtual.

I fully understand your concern :)

But please keep in mind below:

• ONE can be used as dependency in some projects, and these projects can face this build issue and maybe project owners don't want to use -Wno-overloaded-virtual
• in fact overloaded-virtual seems to be quite easy to fix in ONE, even if it's a bit excessive

so, even if opinions about overloaded-virtual usefulness vary, please reconsider fixing these few lines with explicity using to supress compiler doubts :)

I would be grateful, it will help us a lot